Brazilian Journal of Microbiology, Volume: 44, Issue: 1, Published: 2013
  • Prebiotic inulin: Useful dietary adjuncts to manipulate the livestock gut microflora Review

    Samanta, A.K.; Jayapal, Natasha; Senani, S.; Kolte, A.P.; Sridhar, Manpal

    Abstract in English:

    In recent years, there has been a growing appreciation on the relevance of gastrointestinal microflora in both ruminants and non-ruminants owing to revelation of their role in several physiological functions including digestion, nutrient utilization, pathogen exclusion, gastrointestinal development, immunity system, gut gene expression and quality of animal products. The ban imposed on the use of antibiotics and hormones in feed has compelled animal researchers in finding an alternative which could overcome the issues of conventional feed additives. Though the concept of prebiotic was evolved keeping in mind the gastrointestinal flora of human beings, presently animal researchers are exploring the efficiency of prebiotic (inulin) for modulating the gut ecosystem of both ruminants and non-ruminants. It was revealed that prebiotic inulin is found to exhibit desirable changes in the gut of non-ruminants like poultry, swine, rabbit etc for augmenting gut health and improvement of product quality. Similarly, in ruminants the prebiotic reduces rumen ammonia nitrogen, methane production, increase microbial protein synthesis and live weight gains in calves. Unlike other feed additives, prebiotic exhibits its effect in multipronged ways for overall increase in the performances of the animals. In coming days, it is expected that prebiotics could be the part of diets in both ruminants and non-ruminants for enabling modulation of gut microflora vis a vis animals productivity in ecological ways.
  • Molecular identification of Lactobacillus spp. associated with puba, a Brazilian fermented cassava food Food Microbiology

    Crispim, S.M.; Nascimento, A.M.A.; Costa, P.S.; Moreira, J.L.S.; Nunes, A.C.; Nicoli, J.R.; Lima, F.L.; Mota, V.T.; Nardi, R.M.D.

    Abstract in English:

    Puba or carimã is a Brazilian staple food obtained by spontaneous submerged fermentation of cassava roots. A total of 116 lactobacilli and three cocci isolates from 20 commercial puba samples were recovered on de Man, Rogosa and Sharpe agar (MRS); they were characterized for their antagonistic activity against foodborne pathogens and identified taxonomically by classical and molecular methods. In all samples, lactic acid bacteria were recovered as the dominant microbiota (7.86 ± 0.41 log10 CFU/g). 16S-23S rRNA ARDRA pattern assigned 116 isolates to the Lactobacillus genus, represented by the species Lactobacillus fermentum (59 isolates), Lactobacillus delbrueckii (18 isolates), Lactobacillus casei (9 isolates), Lactobacillus reuteri (6 isolates), Lactobacillus brevis (3 isolates), Lactobacillus gasseri (2 isolates), Lactobacillus nagelii (1 isolate), and Lactobacillus plantarum group (18 isolates). recA gene-multiplex PCR analysis revealed that L. plantarum group isolates belonged to Lactobacillus plantarum (15 isolates) and Lactobacillus paraplantarum (3 isolates). Genomic diversity was investigated by molecular typing with rep (repetitive sequence)-based PCR using the primer ERIC2 (enterobacterial repetitive intergenic consensus). The Lactobacillus isolates exhibited genetic heterogeneity and species-specific fingerprint patterns. All the isolates showed antagonistic activity against the foodborne pathogenic bacteria tested. This antibacterial effect was attributed to acid production, except in the cases of three isolates that apparently produced bacteriocin-like inhibitory substances. This study provides the first insight into the genetic diversity of Lactobacillus spp. of puba.
  • Prediction of acid lactic-bacteria growth in turkey ham processed by high hydrostatic pressure Food Microbiology

    Mathias, S.P.; Rosenthal, A.; Gaspar, A.; Aragão, G.M.F.; Slongo-Marcusi, A.

    Abstract in English:

    High hydrostatic pressure (HHP) has been investigated and industrially applied to extend shelf life of meat-based products. Traditional ham packaged under microaerophilic conditions may sometimes present high lactic acid bacteria population during refrigerated storage, which limits shelf life due to development of unpleasant odor and greenish and sticky appearance. This study aimed at evaluating the shelf life of turkey ham pressurized at 400 MPa for 15 min and stored at 4, 8 and 12 ºC, in comparison to the non pressurized product. The lactic acid bacteria population up to 10(7) CFU/g of product was set as the criteria to determine the limiting shelf life According to such parameter the pressurized sample achieved a commercial viability within 75 days when stored at 4 ºC while the control lasted only 45 days. Predictive microbiology using Gompertz and Baranyi and Roberts models fitted well both for the pressurized and control samples. The results indicated that the high hydrostatic pressure treatment greatly increased the turkey ham commercial viability in comparison to the usual length, by slowing down the growth of microorganisms in the product.
  • Influence of carvacrol and thymol on the physiological attributes, enterotoxin production and surface characteristics of Staphylococcus aureus strains isolated from foods Food Microbiology

    Souza, E.L.; Oliveira, C.E.V.; Stamford, T.L.M.; Conceição, M.L.; Gomes Neto, N.J.

    Abstract in English:

    This study evaluated the influence of the phenolic compounds carvacrol (CAR) and thymol (THY) on some physiological characteristics and on the modulation of the secretion of some staphylococcal virulence factors, that is, coagulase and enterotoxin. This study also investigated possible mechanisms for the establishment of the anti-staphylococcal activity of these compounds. Sublethal concentrations (0.3 and 0.15 µL/mL) of CAR and THY inhibited the activity of the enzymes coagulase and lipase and led to a decrease in salt tolerance. At the tested sublethal concentrations, both CAR and THY led to a total suppression of enterotoxin production. The loss of a 260-nm-absorbing material and an efflux of potassium ions occurred immediately after the addition of CAR and THY at 0.6 and 1.2 µL/mL and increased up to 120 min of exposure. Electron microscopy of cells exposed to CAR and THY (0.6 µL/mL) revealed that individual cells appeared to be deformed, with projections of cellular material. The observations of leakage of cellular material and an altered cell surface suggest that gross damage to a cell's cytoplasmic membrane, which results in a disruption in protein secretion, could be responsible for the anti-staphylococcal properties of CAR and THY.
  • Detection of Salmonella spp, Salmonella Enteritidis and Typhimurium in naturally infected broiler chickens by a multiplex PCR-based assay Food Microbiology

    Paião, F.G.; Arisitides, L.G.A.; Murate, L.S.; Vilas-Bôas, G.T.; Vilas-Boas, L.A.; Shimokomaki, M.

    Abstract in English:

    The presence of Salmonella in the intestinal tract, on the chickens skin and among their feathers, may cause carcasses contamination during slaughtering and processing and possibly it is responsible by the introduction of this microorganism in the slaughterhouses. A rapid method to identify and monitor Salmonella and their sorovars in farm is becoming necessary. A pre-enriched multiplex polymerase chain reaction (m-PCR) assay employing specific primers was developed and used to detect Salmonella at the genus level and to identify the Salmonella enterica serovar Enteritidis (S. Enteritidis) and Salmonella enterica serovar Typhimurium (S. Typhimurium) in broiler chicken swab samples. The method was validated by testing DNA extract from 90 fresh culture cloacal swab samples from poultry chicken cultured in phosphate buffer peptone water at 37 ºC for 18 h. The final results showed the presence of Salmonella spp. in 25% of samples, S. Enteritidis was present in 12% of the Salmonella-positive samples and S. Typhimurium in 3% of the samples. The m-PCR assay developed in this study is a specific and rapid alternative method for the identification of Salmonella spp. and allowed the observation of specific serovar contamination in the field conditions within the locations where these chickens are typically raised.
  • Bio-preservation of ground beef meat by Enterococcus faecalis CECT7121 Food Microbiology

    Sparo, M.D.; Confalonieri, A.; Urbizu, L.; Ceci, M.; Sánchez Bruni, S.F.

    Abstract in English:

    Meat and particularly ground beef is frequently associated with Food Poisoning episodes and breeches in Food Safety. The main goal of this research was to evaluate the bactericide effect of the probiotic Enterococcus faecalis CECT7121, against different pathogens as: Escherichia coli O157:H7, Staphylococcus aureus, Clostridium perfringens and Listeria monocytogenes, inoculated in ground beef meat. Three studies were performed to evaluate the inhibition of E. faecalis CECT7121 on ground beef meat samples inoculated with pathogens: Study I: Samples (100 g meat) were inoculated with pathogens (10³ CFU/g)) and E. faecalis CECT7121 (10(4) CFU/g) simultaneously. Study II: Samples were inoculated with E. faecalis CECT7121 24 h before the pathogens. Study III: E. faecalis CECT7121were inoculated 24 h after pathogens. The viable counts were performed at 0, 24, 48 and 72 h post-inoculation. The simultaneous inoculation of E. faecalis CECT7121 with E. coli O157:H7 strains resulted in the absence of viable counts of bacteria at 72 h post-treatment. However, when the probiotic was added 24 h before and 24 h after the pathogen E. coli O157:H7, viable cells were not detected at 24 h and 48 h post-treatment, respectively. Consistently, neither S. aureus nor Cl. perfringens viable bacteria were detected at 48 h in whole assays when inoculated with E. faecalis CECT7121. The same trend than described before was obtained after applying the 3 models assayed for L. monocytogenes. The current assays demonstrated the bactericide activity of E. faecalis CECT7121 strain on bacterial pathogens in ground beef meat.
  • Formation of biofilm by Listeria monocytogenes ATCC 19112 at different incubation temperatures and concentrations of sodium chloride Food Microbiology

    Lee, H.Y.; Chai, L.C.; Pui, C.F.; Mustafa, S.; Cheah, Y.K.; Nishibuchi, M.; Radu, S.

    Abstract in English:

    Biofilm formation can lead to various consequences in the food processing line such as contamination and equipment breakdowns. Since formation of biofilm can occur in various conditions; this study was carried out using L. monocytogenes ATCC 19112 and its biofilm formation ability tested under various concentrations of sodium chloride and temperatures. Cultures of L. monocytogenes ATCC 19112 were placed in 96-well microtitre plate containing concentration of sodium chloride from 1-10% (w/v) and incubated at different temperature of 4 ºC, 30 ºC and 45 ºC for up to 60 h. Absorbance reading of crystal violet staining showed the density of biofilm formed in the 96-well microtitre plates was significantly higher when incubated in 4 ºC. The formation of biofilm also occurs at a faster rate at 4 ºC and higher optical density (OD 570 nm) was observed at 45 ºC. This shows that storage under formation of biofilm that may lead to a higher contamination along the processing line in the food industry. Formation of biofilm was found to be more dependent on temperature compared to sodium chloride stress.
  • Antagonistic activity of Lactobacillus acidophilus LA10 against Salmonella enterica serovar Enteritidis SE86 in mice Food Microbiology

    Scapin, Diane; Grando, Williani Fabiola; Rossi, Eliandra Mirlei; Perez, Karla Joseane; Malheiros, Patrícia da Silva; Tondo, Eduardo Cesar

    Abstract in English:

    Salmonella enterica serovar Enteritidis is one of the main pathogens responsible for foodborne illness in Brazil. Probiotic bacteria can play a role in defense and recovery from enteropathogenic -infections. In this study, the ability of Lactobacillus acidophilus LA10 to colonise and exert anta-gonistic effects in the gastrointestinal tract was tested before and during experimental infection in conventional mice contaminated with S. Enteritidis (SE86). A dose of 0.1 mL containing 10(8) viable cells of SE86 and L. acidophilus LA10 was orally administered by gavage to mice. The experiment was divided into groups. As a negative control, Group 1 was administered only sterile saline solution. As a positive control, Group 2 was administered only SE86. Group 3 was first administered SE86, and after 10 days, treated with L. acidophilus LA10. Group 4 was first administered L. acidophilus LA10,and after 10 days, challenged with SE86.The results demonstrated that a significant number of SE86 cells were able to colonize the gastrointestinal tract of mice, specifically in the colon and ileum. L. acidophilus LA10 demonstrated an antagonistic effect against SE86, with better results observed for Group 3 over Group 4. Thus, L. acidophilus LA10 shows potential antagonistic effects against S. Enteritidis SE86, especially if administered after infection.
  • Antibacterial efficacy of Nisin, Pediocin 34 and Enterocin FH99 against Listeria monocytogenes and cross resistance of its bacteriocin resistant variants to common food preservatives Food Microbiology

    Kaur, G.; Singh, T.P.; Malik, R.K.

    Abstract in English:

    Antilisterial efficiency of three bacteriocins, viz, Nisin, Pediocin 34 and Enterocin FH99 was tested individually and in combination against Listeria mononcytogenes ATCC 53135. A greater antibacterial effect was observed when the bacteriocins were combined in pairs, indicating that the use of more than one LAB bacteriocin in combination have a higher antibacterial action than when used individually. Variants of Listeria monocytogenes ATCC 53135 resistant to Nisin, Pediocin 34 and Enterocin FH99 were developed. Bacteriocin cross-resistance of wild type and their corresponding resistant variants were assessed and results showed that resistance to a bacteriocin may extend to other bacteriocins within the same class. Resistance to Pediocin 34 conferred cross resistance to Enterocin FH 99 but not to Nisin. Similarly resistance to Enterocin FH99 conferred cross resistance to Pediocin 34 but not to Nisin. Also, the sensitivity of Nisin, Pediocin 34 and Enterocin FH99 resistant variants of Listeria monocytogenes to low pH, salt, sodium nitrite, and potassium sorbate was assayed in broth and compared to the parental wild-type strain. The Nisin, Pediocin 34 and Enterocin FH99 resistant variants did not have intrinsic resistance to low pH, sodium chloride, potassium sorbate, or sodium nitrite. In no case were the bacteriocin resistant Listeria monocytogenes variants examined were more resistant to inhibitors than the parental strains.
  • Reduction of Aeromonas hidrophyla biofilm on stainless stell surface by essential oils Food Microbiology

    Millezi, Alessandra Farias; Cardoso, Maria das Graças; Alves, Eduardo; Piccoli, Roberta Hilsdorf

    Abstract in English:

    This study demonstrates the possibility of using sanitizing detergents based on natural products for the elimination and/or reduction of Aeromonas hydrophila biofilm formed on stainless steel surfaces. The goal of this work was to determine the reduction effect of sanitizing detergents containing essential oils of Thymus vulgaris (thyme) and Cymbopogon citratus (lemongrass) on biofilm formed by A. hydrophila on AISI 304 stainless steel coupons, using UHT skimmed milk as substratum. There was adhesion and biofilm formation by A. hydrophila at 28 ºC, presenting 7.60 log cfu.cm-2 after the fourth day of cultivation. There was no significant difference between the lemongrass treatment and that of the thyme oil (p < 0.05). However, both treatments significantly reduced the biofilm, differing significantly from the NaOH control (p > 0.05). The treatment with lemongrass solution reduced the biofilm by 4.51 log cfu cm-2 at 25 ºC. The thyme detergent also reduced the number of cfu cm-2 by 3.84 log cycles at 25 ºC. The use of the lemongrass and thyme solutions efficiently reduced the A. hydrophila biofilm.
  • Occurrence of Brettanomyces/Dekkera in Brazilian red wines and its correlation with ethylphenols Food Microbiology

    Ávila, Larissa Dias de; Ayub, Marco Antônio Záchia

    Abstract in English:

    The yeast Brettanomyces/Dekkeracan cause important spoilage in wines, with the production of ethylphenols and other off-flavor compounds. This study aimed at determining the presence of this yeast and the ethylphenols produced by them in Brazilian red wines, establishing their relationship with other chemical characteristics. Isolates of Brettanomyces/Dekkerawere quantified by plating 126 samples of dry red wine in selective culture medium, while ethylphenols were analyzed by solid phase extraction and GC/FID. Free and total SO2, alcohol, total dry extract, residual sugar, total and volatile acidity, and pH were also determined. Brettanomyces/Dekkerawas present in 27% of samples. Ethylphenols were detected in most samples, with amounts higher than the threshold limit of 426 mg/L found in 46.03% of samples. The majority of wine samples showed inadequate levels of SO2and residual sugars, facts that might facilitate microbial spoilage. The passage in barrels and the grape varieties (Cabernet Sauvignon and Merlot), did not show any influence on the levels of contamination or ethylphenols contents. The prevalence of Brettanomyces/Dekkeraand the concentrations of ethylphenols were high considering the sensory impact they can cause. The growth of Brettanomyces/Dekkerawas dependent on the levels of SO2and alcohol of wines. Knowledge of the contamination, the presence of ethylphenols, and their relationship with the chemical characteristics of wines can entice effective measures to prevent Brettanomyces/Dekkeraand contribute to improve the general quality of Brazilian red wines.
  • Fusarium species and fumonisins associated with maize kernels produced in Rio Grande do Sul State for the 2008/09 and 2009/10 growing seasons Food Microbiology

    Stumpf, R.; Santos, J. dos; Gomes, L.B.; Silva, C.N.; Tessmann, D.J.; Ferreira, F.D.; Machinski Junior, M.; Del Ponte, E.M.

    Abstract in English:

    Ear rots caused by Fusarium spp. are among the main fungal diseases that contribute to poor quality and the contamination of maize grains with mycotoxins. This study aimed to determine the visual incidence of fungal-damaged kernels (FDKs), the incidence of two main Gibberella (a teleomorph of Fusarium) complexes (G. fujikuroi and G. zeae) associated with maize using a seed health blotter test, and the fumonisin levels, using high performance liquid chromatography, in samples of maize grains grown across 23 municipalities during the 2008/09 and 2009/10 growing seasons. Additionally, 104 strains that were representative of all of the analysed samples were identified to species using PCR assays. The mean FDK was seven per cent, and only six of the samples had levels greater than six per cent. Fusarium spp. of the G. fujikuroi complex were present in 96% of the samples, and G. zeae was present in 18% of the samples (5/27). The mean incidence of G. fujikuroi was 58%, and the incidence of G. zeae varied from 2 to 6%. FB1 was found in 58.6%, FB2 in 37.9%, and both toxins in 37.9% of the samples. The FB1 and FB2 levels were below the quantification limits for 41.3% of the samples, and the mean FB1 levels (0.66 µg/g) were higher than the mean FB2 levels (0.42 µg/g). The PCR identification separated the 104 isolates into three of the G. fujikuroi complex: F. verticillioides (76%), F. subglutinans (4%) and F. proliferatum (2%); and G. zeae (anamorph = F. graminearum) (18%). Our results confirmed the dominance of F. verticillioides, similar to other regions of Brazil, but they differed due to the relatively higher incidence of F. graminearum. Total fumonisin levels were below the maximum limit determined by current Brazilian regulations.
  • Fecal indicators and bacterial pathogens in bottled water from Dhaka, Bangladesh Food Microbiology

    Ahmed, W.; Yusuf, R.; Hasan, I.; Ashraf, W.; Goonetilleke, A.; Toze, S.; Gardner, T.

    Abstract in English:

    Forty-six bottled water samples representing 16 brands from Dhaka, Bangladesh were tested for the numbers of total coliforms, fecal indicator bacteria (i.e., thermotolerant Escherichia coli and Enterococcus spp.) and potential bacterial pathogens (i.e., Aeromonas hydrophil, Pseudomonas aeruginos, Salmonella spp., and Shigella spp.). Among the 16 brands tested, 14 (86%), ten (63%) and seven (44%) were positive for total coliforms, E. coil and Enterococcus spp., respectively. Additionally, a further nine (56%), eight (50%), six (37%), and four (25%) brands were PCR positive for A. hydrophila lip, P. aeruginosa ETA, Salmonella spp. invA, and Shigella spp. ipaH genes, respectively. The numbers of bacterial pathogens in bottled water samples ranged from 28 ± 12 to 600 ± 45 (A. hydrophila lip gene), 180 ± 40 to 900 ± 200 (Salmonella spp. invA gene), 180 ± 40 to 1,300 ± 400 (P. aeruginosa ETA gene) genomic units per L of water. Shigella spp. ipaH gene was not quantifiable. Discrepancies were observed in terms of the occurrence of fecal indicators and bacterial pathogens. No correlations were observed between fecal indicators numbers and presence/absence of A. hydrophila lip (p = 0.245), Salmonella spp. invA (p = 0.433), Shigella spp. ipaH gene (p = 0.078), and P. aeruginosa ETA (p = 0.059) genes. Our results suggest that microbiological quality of bottled waters sold in Dhaka, Bangladesh is highly variable. To protect public health, stringent quality control is recommended for the bottled water industry in Bangladesh.
  • Microbial spoilage of portuguese chouriço along shelf life period Food Microbiology

    Matos, Teresa de Jesus da Silva; Bruno-Soares, Arminda; Azevedo, António Amaral

    Abstract in English:

    Microbial flora of portuguese chouriço (Alentejano (A) and Ribatejano (R)) with abnormal sensorial characteristics along shelf life was studied. Mesophilic anaerobic bacteria, enterococci, mesophilic sporeformers, coliforms, coagulase-positive staphylococci, sulphite reducing clostridia, Clostridium perfringens, moulds and yeasts were the most representative in both types of chouriço.
  • Comparison of phenotypic and molecular tests to identify lactic acid bacteria Food Microbiology

    Moraes, Paula Mendonça; Perin, Luana Martins; Silva Júnior, Abelardo; Nero, Luís Augusto

    Abstract in English:

    Twenty-nine lactic acid bacteria (LAB) isolates were submitted for identification using Biolog, API50CHL, 16S rDNA sequencing, and species-specific PCR reactions. The identification results were compared, and it was concluded that a polyphasic approach is necessary for proper LAB identification, being the molecular analyzes the most reliable.
  • Identification and assessment of kefir yeast potential for sugar/ethanol-resistance Food Microbiology

    Miguel, M.G.C.P.; Cardoso, P.G.; Magalhães-Guedes, K.T.; Schwan, R.F.

    Abstract in English:

    Biochemical and molecular analysis was used for identification of different kefir yeasts species from Brazil, Canada and the United States of America. The sugar/ethanol-resistant activity of the yeasts was evaluated. Saccharomyces cerevisiae and Kluyveromyces marxianus had the highest growth rates, suggesting biotechnological applications possible for these strains.
  • Comparison of methods for the detection of biofilm formation by Staphylococcus aureus isolated from bovine subclinical mastitis Veterinary Microbiology

    Melo, Poliana de Castro; Ferreira, Luciano Menezes; Nader Filho, Antônio; Zafalon, Luiz Francisco; Vicente, Hinig Isa Godoy; Souza, Viviane de

    Abstract in English:

    Biofilm formation is considered to be a selective advantage for Staphylococcus aureus mastitis isolates by facilitating bacterial persistence in the udder. It requires attachment to mammary epithelium, proliferation and accumulation of cells in multilayers. The objective of this study was to determine the sensitivity and specificity of three techniques for the detection of S. aureus biofilm-positive strains. Two phenotypic tests, including growth on microtitre plates and Congo red agar, were compared with a PCR technique using 94 S. aureus strains obtained from cows with subclinical mastitis from two farms in the state of São Paulo. These strains were characterised by in vitro slime production on Congo red agar, biofilm formation on microtitre plates and the presence of the icaA and icaD genes. The results revealed that 85% of the isolates tested produced slime on the Congo red agar, 98.9% of the isolates produced biofilms in vitro by adhering to sterile 96-well "U" bottom polystyrene tissue culture plates, and 95.7% of the isolates carried the icaA and icaD genes. The results of the phenotypic tests for biofilm formation were compared with those of the molecular analysis, and the sensitivity and specificity of the Congo red agar test were 88.9% and 100%, respectively, while those of the microtitre plate test were 100% and 25%, respectively. When the phenotypic methods for the detection of biofilm producers, namely growth on microtitre plates and Congo red agar, were compared, the sensitivity and specificity were 86% and 100%, respectively. Therefore, growth on Congo red agar and the microtitre plate test are methods that could be used to determine whether an isolate has the potential for biofilm production.
  • Zoonoses in humans from small rural properties in Jataizinho, Parana, Brazil Veterinary Microbiology

    Gonçalves, Daniela Dib; Benitez, Aline; Lopes-Mori, Fabiana Maria Ruiz; Alves, Lucimara Aparecida; Freire, Roberta Lemos; Navarro, Italmar Teodorico; Santana, Maria Aparecida Zanella; Santos, Luís Roberto Alves dos; Carreira, Teresa; Vieira, Maria Luísa; Freitas, Julio Cesar de

    Abstract in English:

    The aim of this study was to conduct a serological survey for Lyme diseases, brucellosis, leptospirosis and toxoplasmosis and identify the risk variables related to these zoonoses in humans living in the rural area of Jataizinho, state of Parana, Brazil. A total of 63 rural properties were surveyed. Additionally, 207 serum samples collected from these rural area inhabitants were tested for indirect immunofluorescence (IFI) and western blots (WB) were performed to detect Borrelia burgdorferi (sensu lato); a tamponated acidified antigen test (AAT) and 2-mercaptoethanol (2-ME) were used to detect antibodies of Brucella abortus; the microscopic agglutination test (MAT) was carried out to detect antibodies anti-Leptospira spp. and IFI was used to find antibodies of Toxoplasma gondii. Two of the samples (0.96%) were reactive for Lyme borreliosis, three (1.4%) for brucellosis, 25 (12.1%) for leptospirosis and 143 (69.1%) for toxoplasmosis. Although the town of Jataizinho has a human development index (IDH) that was considered to be average (0.733) in the state of Parana, the low social, economic and cultural conditions of the population from small rural properties have resulted in lack of basic information on animal health and direct or indirect contact with the various species of domestic animals, wildlife and ticks have probably contributed to the prevalence levels found. These results show the need for additional regional studies in order to determine the epidemiological characteristics of these diseases as well as their respective vectors and reservoirs so that effective prophylaxis can be administered in the human population.
  • Detection of toxins A/B and isolation of Clostridium difficile and Clostridium perfringens from dogs in Minas Gerais, Brazil Veterinary Microbiology

    Silva, Rodrigo Otávio Silveira; Santos, Renata Lara Resende; Pires, Prhiscylla Sadanã; Pereira, Luiz Carlos; Pereira, Silvia Trindade; Duarte, Marina Carvalho; Assis, Ronnie Antunes de; Lobato, Francisco Carlos Faria

    Abstract in English:

    The objective of this study was to detect C. difficileA/B toxins and to isolate strains of C. perfringensand C. difficile from diarrheic and non-diarrheic dogs in Brazil. Stool samples were collected from 57 dogs, 35 of which were apparently healthy, and 22 of which were diarrheic. C. difficileA/B toxins were detected by ELISA, and C. perfringensand C. difficilewere identified by multiplex PCR. C. difficileA/B toxins were detected in 21 samples (36.8%). Of these, 16 (76.2%) were from diarrheic dogs, and five (23.8%) were from non-diarrheic dogs. Twelve C. difficile strains (21.1%) were isolated, of which ten were A+B+and two were A-B-. All non-toxigenic strains were isolated from non-diarrheic animals. The binary toxin gene cdtBwas found in one strain, which was A+B+and was derived from a non-diarrheic dog. C. perfringensstrains were isolated from 40 samples (70.2%). Of these, 18 (45%) were from the diarrheic group, and 22 (55%) belonged to the non-diarrheic group. All isolates were classified as C. perfringenstype A and there was an association between the detection of the cpegene and the presence of diarrhea. Interestingly, ten strains (25%) were positive for the presence of the cpb2gene. The high rate of detection of the A/B toxins in non-diarrheic dogs suggests the occurrence of subclinical disease in dogs or carriage of its toxins without disease. More studies are needed to elucidate the epidemiology of C. difficileand C. perfringensin dogs and to better our understanding of C. difficileas a zoonotic agent. This is the first study to report the binary toxin gene in C. difficilestrains isolated from dogs in Brazil.
  • Clinical and mycological analysis of dog's oral cavity Veterinary Microbiology

    Santin, Rosema; Mattei, Antonella Souza; Waller, Stefanie Bressan; Madrid, Isabel Martins; Cleff, Marlete Brum; Xavier, Melissa Orzechowski; Nobre, Márcia de Oliveira; Nascente, Patrícia da Silva; Mello, João Roberto Braga de; Meireles, Mário Carlos Araújo

    Abstract in English:

    The oral microbiota of humans and animals is made up of a wide variety of yeasts and bacteria, but microbiota of dogs is not totally described. Although such identification is an important step to establish the etiopathogenesis and adequate therapy for the periodontal disease The aim of this study was to evaluate and correlate oral alterations with the presence of yeasts in oral cavity of female dogs. After clinical evaluation samples from healthy and from dogs with oral diseases were obtained from three different oral sites by swabs, curettes, millimeter periodontal probes and HA membrane tip in cellulose ester. Yeast identification was performed through macroscopic and microscopic colony features and biochemical tests. Dental calculus was the most prevalent occurrence in the oral cavity of 59 females. However, the isolation of yeasts was significantly higher (p < 0.05) in animals suffering from halitosis. Eleven yeast species were identified, namely: Malassezia pachydermatis, Rhodotorula spp., Candida albicans, C. catenulata, C. famata, C. guilliermondii, C. parapsilosis, C. intermedia, Trichosporon asahii, T. mucoides and Cryptococcus albidus. It could be concluded that the yeasts are part of the microbiota from the different sites of the oral cavity of the female canines studied without causing any significant alterations except halitosis.
  • The prevalence of swine enteropathogens in Brazilian grower and finish herds Veterinary Microbiology

    Viott, A.M.; Lage, A.P.; Cruz Junior, E.C.C.; Guedes, R.M.C.

    Abstract in English:

    Diarrhoea among growing and finishing pigs is an important problem in many herds. The prevalence of L. intracellularis, B. pilosicoli, B. hyodysenteriae, Salmonella spp., enterotoxigenic E. coli, Trichuris suis and the occurrence of mixed infection were investigated. Fecal samples for forty-six herds with diarrhea or a history of diarrhea were randomly collected in Minas Gerais state, Brazil. The enteric pathogens were detected by culture (E. coli and Salmonella sp.), PCR (L. intracellularis and Brachyspira spp.) and eggs counts (T. suis). The overall herd prevalence of L. intracellularis, Salmonella enterica serotype Typhimurium and enterotoxigenic E. coli were 19.56%, 6.52%, 10.86% respectively. Mixed infection was diagnosed in 30.43% of herds, and L. intracellularis and Salmonella enterica serotype Typhimurium are main pathogens association (10.87%). B. pilosicoli was diagnosed only in two herds, always associated with mixed infections. B. hyodysenteriae and T. suis were not demonstrated in any sample. These pathogens have been reported world-wide but studies regarding epidemiology in Brazil are few. This study contributes to establish of prevention programs for the control enteropathogens in grower finish herds in Brazil.
  • Relationship between Paratuberculosis and the microelements Copper, Zinc, Iron, Selenium and Molybdenum in Beef Cattle Veterinary Microbiology

    Paolicchi, F.; Perea, J.; Cseh, S.; Morsella, C.

    Abstract in English:

    To study the deficiency of minerals and its relationship with Paratuberculosis, blood, serum, and fecal samples were obtained from 75 adult bovines without clinical symptoms of the disease and from two bovines with clinical symptoms of the disease, from two beef herds with a previous history of Paratuberculosis in the Province of Buenos Aires, Argentina. Serum samples were processed by ELISA and feces were cultured in Herrolds medium. Copper, zinc and iron in serum were quantified by spectrophotometry and selenium was measured by the activity of glutathione peroxidase. We also determined copper, zinc, iron and molybdenum concentrations in pastures and the concentration of sulfate in water. Mycobacterium avium subsp paratuberculosis (Map) was isolated from 17.3% of fecal samples of asymptomatic animals and from the fecal samples from the two animals with clinical symptoms. All the Map-positive animals were also ELISA-positive or suspect, and among them, 84.6% presented low or marginal values of selenium and 69.2% presented low or marginal values of copper. The two animals with clinical symptoms, and isolation of Map from feces and organs were selenium-deficient and had the lowest activity of glutathione peroxidase of all the animals from both herds. All the animals negative to Map in feces and negative to ELISA had normal values of Se, while 13.8% of animals with positive ELISA or suspect and culture negative presented low levels of Se. Half of the animals that were negative both for ELISA and culture in feces were deficient in copper but none of them presented low values of selenium. The content of molybdenum and iron in pasture was high, 2.5 ppm and 1.13 ppm in one herd and 2.5 ppm and 2.02 ppm in the other, respectively, whereas the copper:molybdenum ratio was 1.5 and 5.2, respectively. These results do not confirm an interaction between imbalances of the micronutrients and clinical Paratuberculosis, but show evidence of the relationship between selenium deficiencies in animals with Map infection and ELISA positive results.
  • Identification and antimicrobial susceptibility patterns of Pasteurella multocida isolated from chickens and japanese quails in Brazil Veterinary Microbiology

    Rigobelo, Everlon Cid; Blackall, Patrick Joseph; Maluta, Renato Pariz; Ávila, Fernando Antonio de

    Abstract in English:

    A study was performed to verify the presence of Pasteurella multocida in eight different poultry groups of 90 birds each. Groups I to IV were chickens (I being > 6 weeks of age with a history of respiratory illness, II > 6 weeks of age and free of respiratory illness, III < 6 weeks of age with respiratory illness and IV being < 6 weeks of age and with no respiratory illness. Groups V to VIII had the matching characteristics of Groups I to V but consisted of Japanese Quails. The P. multocida isolation rate from the groups was as follows; Group I 56/90 (62.3%) Group II 18/90 (20.0%), Group III 12/90 (13.3%), Group IV 3/90 (3.33%), Group V 8/90 (8.88%), Group VI 2/90 (2.22%) Group VII 2/90 (2.22%) and Group VIII 1/90 (1.11%). These isolation rates were not significantly different within the groups of a bird type but the overall chicken isolation rate was significantly higher than the quail isolation rate (p < 0.01). All isolates were examined for their sensitivity to four antimicrobial agents. The results showed only low levels of resistance to the agents tested. The highest level of resistance detected was to cephalothin (5.1% of isolates) followed by amikacin (3.4%).
  • Characterization of a virulent Leptospira interrogans strain isolated from an abandoned swimming pool Veterinary Microbiology

    Forster, Karine M.; Hartwig, Daiane D.; Seixas, Fabiana K.; McBride, Alan J.A.; Monte, Leonardo G.; Recuero, Ana Lúcia C.; Brod, Claudiomar S.; Hartleben, Cláudia P.; Amaral, Marta; Dellagostin, Odir A.

    Abstract in English:

    Pathogenic Leptospira spp. are the etiological agents of leptospirosis, an important disease of both humans and animals. In urban settings, L. interrogans serovars are the predominant cause of disease in humans. The purpose of this study was to characterize a novel Leptospira isolate recovered from an abandoned swimming pool. Molecular characterization through sequencing of the rpoB gene revealed 100% identity with L. interrogans and variable-number tandem-repeat (VNTR) analysis resulted in a banding pattern identical to L. interrogans serogroup Icterohaemorrhagiae, serovar Copenhageni or Icterohaemorrhagiae. The virulence of the strain was determined in a hamster model of lethal leptospirosis. The lethal dose 50% (LD50) was calculated to be two leptospires in female hamsters and a histopathological examination of infected animals found typical lesions associated with severe leptospirosis, including renal epithelium degeneration, hepatic karyomegaly, liver-plate disarray and lymphocyte infiltration. This highly virulent strain is now available for use in further studies, especially evaluation of vaccine candidates.
  • Isolation of dermatophytes in wild felids from screening centers Veterinary Microbiology

    Albano, Ana Paula N.; Nascente, Patrícia da Silva; Leite, Alice T. Meirelles; Xavier, Melissa O.; Santin, Rosema; Mattei, Antonella Souza; Humberg, Roberta M.P.; Coimbra, Marco Antonio A.; Minello, Luiz Fernando; Meireles, Mario C.A.

    Abstract in English:

    The aim of this study was detect the presence of dermatophyte fungi on wild felids from screening centers. Samples were taken from 30 animals, assembled in two groups: "free-ranging" and "transitory captivity". The dermatophytes (Trichophyton genus), isolated from two felids (6.6%), both of the group "free-ranging".
  • Susceptibility variation of Malassezia pachydermatis to antifungal agents according to isolate source Veterinary Microbiology

    Weiler, Caroline Borges; Jesus, Francielli Pantella Kunz de; Nardi, Graziela Habib; Loreto, Érico Silva; Santurio, Janio Morais; Coutinho, Selene Dall'Acqua; Alves, Sydney Hartz

    Abstract in English:

    Malassezia pachydermatisis associated with dermatomycoses and otomycosis in dogs and cats. This study compared the susceptibility of M. pachydermatis isolates from sick (G1) and healthy (G2) animals to azole and polyene antifungals using the M27-A3 protocol. Isolates from G1 animals were less sensitive to amphotericin B, nystatin, fluconazole, clotrimazole and miconazole.
  • Assessment of the effectiveness of the PPD-mallein produced in Brazil for diagnosing glanders in mules Veterinary Microbiology

    Silva, Karla Patrícia Chaves da; Takaki, Galba Maria de Campos; Silva, Leonildo Bento Galiza da; Saukas, Tomoe Noda; Santos, André Souza; Mota, Rinaldo Aparecido

    Abstract in English:

    To assess the potency of the PPD-mallein produced in Brazil, five animals were from a property identified as a focus of glanders. These animals had suggestive clinical signs of the disease and the other five, from a property free from glanders, showed no clinical signs and were serology negative (control group). PPD-mallein from Burkholderia mallei was obtained by precipitation with trichlo-roa-cetic acid and ammonium sulfate. The animals were inoculated according to the criteria established by Department of Agriculture, Livestock and Supply (MAPA) for the diagnosis of glanders. After 48 h of application of PPD-mallein, there was swelling in the area of application, presence of ocular secretion and tears in sick animals. The control group showed no inflammatory reaction at the site of inoculation of PPD-mallein. This immunogen produced in Brazil and still being tested was effective for identifying the infection in true positive animals and excluding the truly negative ones, being a new possibility for diagnosis and control of glanders.
  • Submerged fermentation of Lactobacillus rhamnosus YS9 for γ-aminobutyric acid (GABA) production Industrial Microbiology

    Lin, Qian

    Abstract in English:

    γ-Aminobutyric acid (GABA) is a major inhibitory neurotransmitter in central nervous system, and its application in drugs and functional foods has attracted great attention. To enhance production of y-aminobutyric acid, Lactobacillus rhamnosus YS9, a strain isolated from Chinese traditional fermented food pickled vegetable, was grown under submerged fermentation. Its cultivation conditions were investigated. When culture pH condition was adjusted to the optimal pH of glutamate decarboxylase activity, culture of Lb. rhamnosus YS9 in medium supplemented with 200 mM of monosodium glutamate and 200 µM of pyridoxal phosphate (PLP), produced 187 mM of GABA.
  • Enhancement of chitosanase production by cell immobilization of Gongronella sp. JG Industrial Microbiology

    Zhang, Pingping; Zhou, Wei; Wang, Peng; Wang, Li; Tang, Mingli

    Abstract in English:

    Chitosanase production of Gongronella sp. JG cells immobilized in calcium alginate gel and polyurethane foam was compared with that of the free cells, there was a 60% increase in the enzyme yield (2429 U/L) compared to the highest yield obtained from free cells (1513 U/L). The optimal immobilization parameters (concentrations of sodium alginate, calcium chloride, bead inoculums, bead diameter, etc) for the enhanced production of chitosanase were determined as: sodium alginate 2% (w/v), 0.1 M calcium chloride, inoculum 10 mL beads to 100 mL production media and 2.7 mm bead diameter. Maximum chitosanase production was achieved with initial pH of 5.5 and temperature of 30 ºC. The alginate beads had well stability, retained 85% ability of enzyme production even after 7 cycles of repeated batch fermentation. These results showed the immobilization technique was a feasible and economical method for chitosansase production by Gongronella sp. JG.
  • Minerals consumption by Acetobacter xylinum on cultivation medium on coconut water Industrial Microbiology

    Almeida, Denise Milleo; Prestes, Rosilene Aparecida; Fonseca, Adriel Ferreira da; Woiciechowski, Adenise L.; Wosiacki, Gilvan

    Abstract in English:

    The objective of this work is to verifying the consume of the minerals K, Na, Fe, Mg, P, S-SO4-2,B,N Total Kjedahl (NTK), NO3--N, and NH4+-N in the production of bacterial cellulose by Acetobacter xylinum, according to the medium and the manner of cultivation. The fermentative process was in ripe and green coconut water. K and Na were determined by flame emission photometry, Mg and Fe by atomic absorption spectrophotometry, P by molecular absorption spectrophotometry, S-SO4-2 by barium sulphate turbidimetry, B by Azomethin-H method, NTK by Kjeldahl method, N-NO3-and N-NH4+ by vapor distillation with magnesium oxide and Devarda's alloy, respectively. In Fermentation of ripe coconut water there were higher consumption of K (69%), Fe (84,3%), P (97,4%), S-SO2-2 (64,9%), B (56,1%), N-NO3 (94,7%) and N-NH4+ (95,2%), whereas coconut water of green fruit the most consumed ions were Na (94,5%), Mg (67,7%) and NTK (56,6%). The cultivation under agitation showed higher mineral consumption. The higher bacterial cellulose production, 6 g.L-1, was verified in the coconut water fermentative in ripe fruit, added KH2PO4, FeSO4 and NaH2PO4 kept under agitation.
  • Secretion of laccase and manganese peroxidase by Pleurotus strains cultivate in solid-state using Pinus spp. sawdust Industrial Microbiology

    Camassola, Marli; Rosa, Letícia O. da; Calloni, Raquel; Gaio, Tamara A.; Dillon, Aldo J.P.

    Abstract in English:

    Pleurotus species secrete phenol oxidase enzymes: laccase (Lcc) and manganese peroxidase (MnP). New genotypes of these species show potential to be used in processes aiming at the degradation of phenolic compounds, polycyclic aromatic hydrocarbons and dyes. Hence, a screening of some strains of Pleurotus towards Lcc and MnP production was performed in this work. Ten strains were grown through solid-state fermentation on a medium based on Pinus spp. sawdust, wheat bran and calcium carbonate. High Lcc and MnP activities were found with these strains. Highest Lcc activity, 741 ± 245 U gdm-1 of solid state-cultivation medium, was detected on strain IB11 after 32 days, while the highest MnP activity occurred with strains IB05, IB09, and IB11 (5,333 ± 357; 4,701 ± 652; 5,999 ± 1,078 U gdm-1, respectively). The results obtained here highlight the importance of further experiments with lignocellulolytic enzymes present in different strains of Pleurotus species. Such results also indicate the possibility of selecting more valuable strains for future biotechnological applications, in soil bioremediation and biological biomass pre-treatment in biofuels production, for instance, as well as obtaining value-added products from mushrooms, like phenol oxidase enzymes.
  • Optimizing a culture medium for biomass and phenolic compounds production using Ganoderma lucidum Industrial Microbiology

    Zárate-Chaves, Carlos Andrés; Romero-Rodríguez, María Camila; Niño-Arias, Fabián Camilo; Robles-Camargo, Jorge; Linares-Linares, Melva; Rodríguez-Bocanegra, María Ximena; Gutiérrez-Rojas, Ivonne

    Abstract in English:

    The present work was aimed at optimizing a culture medium for biomass production and phenolic compounds by using Ganoderma lucidum. The culture was optimized in two stages; a Plackett-Burman design was used in the first one for identifying key components in the medium and a central composite design was used in the second one for optimizing their concentration. Both responses (biomass and phenolic compounds) were simultaneously optimized by the latter methodology regarding desirability, and the optimal concentrations obtained were 50.00 g/L sucrose, 13.29 g/L yeast extract and 2.99 g/L olive oil. Maximum biomass production identified in these optimal conditions was 9.5 g/L and that for phenolic compounds was 0.0452 g/L, this being 100% better than that obtained in the media usually used in the laboratory. Similar patterns regarding chemical characterization and biological activity towards Aspergillus sp., from both fruiting body and mycelium-derived secondary metabolites and extracts obtained in the proposed medium were observed. It was shown that such statistical methodologies are useful for optimizing fermentation and, in the specific case of G. lucidum, optimizing processes for its production and its metabolites in submerged culture as an alternative to traditional culture.
  • Bioethanol production from rice straw residues Industrial Microbiology

    Belal, Elsayed B.

    Abstract in English:

    A rice straw -cellulose utilizing mold was isolated from rotted rice straw residues. The efficient rice straw degrading microorganism was identified as Trichoderma reesei. The results showed that different carbon sources in liquid culture such as rice straw, carboxymethyl cellulose, filter paper, sugar cane bagasse, cotton stalk and banana stalk induced T. reesei cellulase production whereas glucose or Potato Dextrose repressed the synthesis of cellulase. T. reesei cellulase was produced by the solid state culture on rice straw medium. The optimal pH and temperature for T. reesei cellulase production were 6 and 25 ºC, respectively. Rice straw exhibited different susceptibilities towards cellulase to their conversion to reducing sugars. The present study showed also that, the general trend of rice straw bioconversion with cellulase was more than the general trend by T. reesei. This enzyme effectively led to enzymatic conversion of acid, alkali and ultrasonic pretreated cellulose from rice straw into glucose, followed by fermentation into ethanol. The combined method of acid pretreatment with ultrasound and subsequent enzyme treatment resulted the highest conversion of lignocellulose in rice straw to sugar and consequently, highest ethanol concentration after 7 days fermentation with S. cerevisae yeast. The ethanol yield in this study was about 10 and 11 g.L-1.
  • Production and partial characterization of serine and metallo peptidases secreted by Aspergillus fumigatus Fresenius in submerged and solid state fermentatio Industrial Microbiology

    Silva, Ronivaldo Rodrigues da; Cabral, Tatiana Pereira de Freitas; Rodrigues, André; Hamilton, Cabral

    Abstract in English:

    Enzyme production varies in different fermentation systems. Enzyme expression in different fermentation systems yields important information for improving our understanding of enzymatic production induction. Comparative studies between solid-state fermentation (SSF) using agro-industrial waste wheat bran and submerged fermentation (SmF) using synthetic media were carried out to determinate the best parameters for peptidase production by the fungus Aspergillus fumigatus Fresen. Variables tested include: the concentration of carbon and protein nitrogen sources, the size of the inoculum, the pH of the media, temperature, and the length of the fermentation process. The best peptidase production during SSF was obtained after 96 hours using wheat bran at 30 ºC with an inoculum of 1 x 10(6) spores and yielded 1500 active units (UµmL). The best peptidase production using SmF was obtained after periods of 72 and 96 hours of fermentation in media containing 0.5% and 0.25% of casein, respectively, at a pH of 6.0 and at 30 ºC and yielded 40 UµmL. We also found examples of catabolite repression of peptidase production under SmF conditions. Biochemical characterization of the peptidases produced by both fermentative processes showed optimum activity at pH 8.0 and 50 ºC, and also showed that their proteolytic activity is modulated by surfactants. The enzymatic inhibition profile using phenylmethylsulfonyl fluoride (PMSF) in SmF and SSF indicated that both fermentative processes produced a serine peptidase. Additionally, the inhibitory effect of the ethylene-diaminetetraacetic acid (EDTA) chelating agent on the peptidase produced by SmF indicated that this fermentative process also produced a metallopeptidase.
  • Computation of interactive effects and optimization of process parameters for alkaline lipase production by mutant strain of Pseudomonas aeruginosa using response surface methodology Industrial Microbiology

    Bisht, Deepali; Yadav, Santosh Kumar; Darmwal, Nandan Singh

    Abstract in English:

    Alkaline lipase production by mutant strain of Pseudomonas aeruginosa MTCC 10,055 was optimized in shake flask batch fermentation using response surface methodology. An empirical model was developed through Box-Behnken experimental design to describe the relationship among tested variables (pH, temperature, castor oil, starch and triton-X-100). The second-order quadratic model determined the optimum conditions as castor oil, 1.77 mL.L-1; starch, 15.0 g.L-1; triton-X-100, 0.93 mL.L-1; incubation temperature, 34.12 ºC and pH 8.1 resulting into maximum alkaline lipase production (3142.57 U.mL-1). The quadratic model was in satisfactory adjustment with the experimental data as evidenced by a high coefficient of determination (R²) value (0.9987). The RSM facilitated the analysis and interpretation of experimental data to ascertain the optimum conditions of the variables for the process and recognized the contribution of individual variables to assess the response under optimal conditions. Hence Box-Behnken approach could fruitfully be applied for process optimization.
  • Phenotypic and genotypic characterization of Streptococcus agalactiae in pregnant women: first study in a province of Argentina Medical Microbiology

    Oviedo, P; Pegels, E; Laczeski, M; Quiroga, M; Vergara, M

    Abstract in English:

    Group B Streptococcus (GBS) is the leading cause of neonatal infections. Our purpose was to characterize GBS colonization in pregnant women, current serotypes, resistance phenotypes and genes associated with virulence. In Misiones, Argentina, there are no previous data on this topic. Vaginal-rectal swabs from 3125 pregnant women were studied between 2004 and 2010. GBS strains were identified by conventional and serological methods (Phadebact Strep B Test, ETC International, Bactus AB, Sweden). Serotypes were detected using Strep-B Latex (Statens Serum Institut, Denmark). Resistance phenotypes were determined by the double-disk test. Genes were studied by PCR. Maternal colonization was 9.38%. Resistance to erythromycin was 11.6%, and the constitutive phenotype was the predominant one. Serotype Ia was the most frequent, whereas serotypes IV, VI, VII and VIII were not detected. The lmb, bca and hylB genes were detected in more than 79% of the strains. In this study, the colonization rate with GBS and the serotype distribution were compared with studies reported in other areas of the country. The high resistance to erythromycin in Misiones justifies performing antibiotic susceptibility testing. The serotype distribution, the genes encoding putative virulence factors, and the patterns of resistance phenotypes of GBS may vary in different areas. They thus need to be evaluated in each place to devise strategies for prevention.
  • Effect of sub-minimum inhibitory concentrations of ciprofloxacin, amikacin and colistin on biofilm formation and virulence factors of Escherichia coli planktonic and biofilm forms isolated from human urine Medical Microbiology

    Wojnicz, Dorota; Tichaczek-Goska, Dorota

    Abstract in English:

    The aim of this study was to determine the effect of subinhibitory concentrations (sub-MICs) of ciprofloxacin, amikacin and colistin on biofilm formation, motility, curli fimbriae formation by planktonic and biofilm cells of E. coli strains isolated from the urine of patients with various urinary system infections. Quantification of biofilm formation was carried out using a microtiter plate assay and a spectrophotometric method. Bacterial enumeration was used to assess the viability of bacteria in the biofilm. Curli expression was determined by using YESCA agar supplemented with congo red. Using motility agar the ability to move was examined. All the antibiotics used at sub-MICs reduced biofilm formation in vitro, decreased the survival of bacteria, but had no effect on the motility of planktonic as well as biofilm cells. The inhibitory effect of sub-MICs of antimicrobial agents on curli fimbriae formation was dependent on the form in which the bacteria occurred, incubation time and antibiotic used. Our results clearly show that all the three antibiotics tested reduce biofilm production, interfere with curli expression but do not influence motility. This study suggests that ciprofloxacin, amikacin and colistin may be useful in the treatment of biofilm-associated infections caused by E. coli strains.
  • EsxA might as a virulence factor induce antibodies in patients with Staphylococcus aureus infection Medical Microbiology

    Zhou, Huiqin; Du, Hong; Zhang, Haifang; Shen, Haiying; Yan, Ruhong; He, Yun; Wang, Min; Zhu, Xueming

    Abstract in English:

    Staphylococcus aureus (S. aureus) is an important human pathogen, which commonly causes the acquired infectious diseases in the hospital and community. Effective and simple antibiotic treatment against S. aureus-related disease becomes increasingly difficult. Developing a safe and effective vaccine against S. aureus has become one of the world's hot spots once again. The key issue of developing the vaccine of S. aureus is how to find an ideal key pathogenic gene of S. aureus. It was previously suggested that EsxA might be a very important factor in S. aureus abscess formation in mice, but clinical experimental evidence was lacking. We therefore expressed EsxA protein through prokaryotic expression system and purified EsxA protein by Ni-affinity chromatography. ELISA was used to detect the anti-EsxA antibodies in sera of 78 patients with S. aureus infection and results showed that the anti-EsxA antibodies were positive in the sera of 19 patients. We further analyzed the EsxA positive antibodies related strains by antimicrobial susceptibility assay and found that all of the corresponding strains were multi-drug resistant. Among those multi-drug resistant strains, 73.7% were resistant to MRSA. The results indicated EsxA is very important in the pathogenesis of S. aureus. We suggested that the EsxA is very valuable as vaccine candidate target antigens for prevention and control of S. aureus infection.
  • Molecular basis of high-level ciprofloxacin resistance in Neisseria gonorrhoeae strains from Shandong Province, China Medical Microbiology

    Zhao, L.H.; Zhao, S.P.

    Abstract in English:

    In the study, the ciprofloxacin resistance rate was 100%. High-level ciprofloxacin resistance rate was 63.55%. Sixteen different mutation patterns involved in the formation of ciprofloxacin resistance were identified. The most prevalent were patterns P7 (25.2%), P8 (15.0%), P9 (11.2%), P1 (10.3%), and P5 (10.3%). All of the 107 NG isolates analyzed for mutations in the study have demonstrated a change of Ser-91 → Phe in the gyrA gene, and all except one have demonstrated a change in position 95 of the amino acid sequence. All of the 68 high-level QRNG isolates had double mutations in gyrA gene combined with a single or two mutations in parC gene. It is most important that a new mutation site of Ile-97 → Met in gyrA and a new mutation of Leu-106 → Ile in parC were found in the study, both leading to high-level ciprofloxacin resistance (MIC values, 8 µg/mL, 32 µg/mL, respectively). Therefore, we confim that gyrA mutations are necessary for the fluoroquinolone resistance phenotype and parC mutations are correlated intimately with high-level fluoroquinolone resistance. In China fluoroquinolone resistance in Neisseria gonorrhoeae strains is very serious and the new mutation sites in the fluoroquinolone resistance-determining regions emerge more and more quickly. Hence, in China fluoroquinolones, which are used to treat gonorrhoea presently, should be substituted by a new antibiotics.
  • Detection of Staphylococcus aureus with an intermediate profile to vancomycin (VISA) isolate from Santa Maria, RS Medical Microbiology

    Marques, Jaciane Baggiotto; Dalmolin, Tanise Vendruscolo; Bonez, Pauline Cordenonsi; Agertt, Vanessa Albertina; Campos, Marli Matiko Anraku de; Santos, Roberto Christ Vianna

    Abstract in English:

    Twenty-three isolates of Staphylococcus aureus resistant to methicillin have been analyzed, being found a clinical isolate of VISA through microdilution technique. The others techniques were unable to detect such isolates. This is the first study that shows the presence of VISA in clinical isolates in the city of Santa Maria-RS.
  • Comparison of resazurin microtiter assay performance and BACTEC MGIT 960 in the susceptibility testing of Brazilian clinical isolates of Mycobacterium tuberculosis to four first-line drugs Medical Microbiology

    Miyata, Marcelo; Pavan, Fernando Rogério; Sato, Daisy Nakamura; Marino, Leonardo Biancolino; Hirata, Mario Hiroyuki; Cardoso, Rosilene Fressati; Melo, Fernando Augusto Fiúza de; Leite, Clarice Queico Fujimura

    Abstract in English:

    We assessed the performance of REMA in comparison with BACTEC MGIT 960 in the susceptibility testing of 80 Mycobacterium tuberculosis clinical isolates from Clemente Ferreira Institute against four drugs. REMA proved to be a rapid and accurate method, providing excellent correlation with BACTEC MGIT 960, with the exception of results for the ethambutol drug.
  • Measuring of Mycobacterium tuberculosis growth: a correlation of the optical measurements with colony forming units Medical Microbiology

    Peñuelas-Urquides, Katia; Villarreal-Treviño, Licet; Silva-Ramírez, Beatriz; Rivadeneyra-Espinoza, Liliana; Said-Fernández, Salvador; León, Mario Bermúdez de

    Abstract in English:

    The quantification of colony forming units (cfu), turbidity, and optical density at 600 nm (OD600) measurements were used to evaluate Mycobacterium tuberculosis growth. Turbidity and OD600 measurements displayed similar growth curves, while cfu quantification showed a continuous growth curve. We determined the cfu equivalents to McFarland and OD600 units.
  • Properties of catechol 1,2-dioxygenase in the cell free extract and immobilized extract of Mycobacterium fortuitum Environmental Microbiology

    Silva, A.S.; Jacques, R.J.S.; Andreazza, R.; Bento, F.M.; Roesch, L.F.W.; Camargo, F.A.O.

    Abstract in English:

    Polycyclic aromatic hydrocarbons (PAH) are carcinogenic compounds which contaminate water and soil, and the enzymes can be used for bioremediation of these environments. This study aimed to evaluate some environmental conditions that affect the production and activity of the catechol 1,2-dioxygenase (C12O) by Mycobacterium fortuitum in the cell free and immobilized extract in sodium alginate. The bacterium was grown in mineral medium and LB broth containing 250 mg L-1 of anthracene (PAH). The optimum conditions of pH (4.0-9.0), temperature (5-70 ºC), reaction time (10-90 min) and the effect of ions in the enzyme activity were determined. The Mycobacterium cultivated in LB shown higher growth and the C12O activity was two-fold higher to that in the mineral medium. To both extracts the highest enzyme activity was at pH 8.0, however, the immobilized extract promoted the increase in the C12O activity in a pH range between 4.0 and 8.5. The immobilized extract increased the enzymatic activity time and showed the highest C12O activity at 45 ºC, 20 ºC higher than the greatest temperature in the cell free extract. The enzyme activity in both extracts was stimulated by Fe3+, Hg2+ and Mn2+ and inhibited by NH4+ and Cu2+, but the immobilization protected the enzyme against the deleterious effects of K+ and Mg2+ in tested concentrations. The catechol 1,2-dioxygenase of Mycobacterium fortuitum in the immobilized extract has greater stability to the variations of pH, temperature and reaction time, and show higher activity in presence of ions, comparing to the cell free extract.
  • Mucorales from the semiarid of Pernambuco, Brazil Environmental Microbiology

    Santiago, André Luiz Cabral Monteiro de Azevedo; Santos, Paulo Jorge Parreira dos; Maia, Leonor Costa

    Abstract in English:

    Nineteen taxa of Mucorales, belonging to Absidi, Apophysomyces, Cunninghamella, Fennellomyces, Lichtheimi, Mucor, Mycotypha, Rhizopus and Syncephalastrum were isolated from 36 composite soil samples in three semiarid areas in the State of Pernambuco (Triunfo, Cabrobó and Belém de São Francisco), Northeast Brazil, which are characterized by Caatinga vegetation. Triunfo is preserved, whereas Cabroró and Belém de São Francisco are experiencing low and severe desertification processes, respectively. Mucorales were isolated in Petri dishes in triplicate from 5 mg samples of soil placed on the surface of wheat germ agar plus chloramphenicol and Cercobin [Dimethyl 4,49-(103 phenylene) bis (3-thioallophanate)] medium. The plates were left on a bench at room temperature (28 ± 2 ºC) for 72 h of alternating dark and light periods. Absidia cylindrospora presented the highest amount of CFU/g of soil, followed by L. hyalospor, C. phaeospora and C. echinulata var. echinulata. The latter, and R. microsporus var. microsporus, presented the highest frequencies of occurrence. Soils from Triunfo showed higher diversity of Mucorales than the samples from the other areas, although without differing statistically in relation to species richness. The communities of Mucorales from the degraded areas were more similar, while that from the preserved area was quite different. Most of the identified specimens have been commonly isolated from soil in other Brazilian regions, which indicates that they are not endemic of the semiarid. Eleven taxa are registered for the first time in this ecosystem, while F. heterothallicus is reported for the first time in Brazil.
  • Hexavalent chromium reduction by aerobic heterotrophic bacteria indigenous to chromite mine overburden Environmental Microbiology

    Satarupa, Dey; Paul, A.K.

    Abstract in English:

    Microbiological analysis of overburden samples collected from chromite mining areas of Orissa, India revealed that they are rich in microbial density as well as diversity and dominated by Gramnegative (58%) bacteria. The phenotypically distinguishable bacterial isolates (130) showed wide degree of tolerance to chromium (2-8 mM) when tested in peptone yeast extract glucose agar medium. Isolates (92) tolerating 2 mM chromium exhibited different degrees of Cr+6 reducing activity in chemically defined Vogel Bonner (VB) broth and complex KSC medium. Three potent isolates, two belonging to Arthrobacter spp. and one to Pseudomonas sp. were able to reduce more than 50 and 80% of 2 mM chromium in defined and complex media respectively. Along with Cr+6 (MIC 8.6-17.8 mM), the isolates showed tolerance to Ni+2, Fe+3, Cu+2 and Co+2 but were extremely sensitive to Hg+2 followed by Cd+2, Mn+2 and Zn+2. In addition, they were resistant to antibiotics like penicillin, methicillin, ampicillin, neomycin and polymyxin B. During growth under shake-flask conditions, Arthrobacter SUK 1201 and SUK 1205 showed 100% reduction of 2 mM Cr+6 in KSC medium with simultaneous formation of insoluble precipitates of chromium salts. Both the isolates were also equally capable of completely reducing the Cr+6 present in mine seepage when grown in mine seepage supplemented with VB concentrate.
  • Isolation, morphological and molecular characterization of phytate-hydrolysing fungi by 18S rDNA sequence analysis Environmental Microbiology

    Gontia-Mishra, Iti; Deshmukh, Dhanshree; Tripathi, Niraj; Bardiya-Bhurat, Khushboo; Tantwai, Keerti; Tiwari, Sharad

    Abstract in English:

    Phytate is the primary storage form of phosphate in plants. Monogastric animals like poultry, pigs and fishes have very low or no phytase activities in their digestive tracts therefore, are incapable to efficiently utilize phytate phosphorus from the feed. Phytase from microbial sources are supplemented to feedstuff of these to increase the uptake of phytate phosphorus. In the present work efforts were made to isolate and characterize proficient phytase producing fungi from soil. Phytase producing fungi were isolated using phytate specific medium. Fungal isolates were selected according to their higher phytase activities. These isolates were further characterized and identified by morphological and microscopic analysis and confirmed by amplification of 18S rRNA gene, using specific primers. This gene was subsequently sequenced and phylogenetic affiliations were assigned. Fungal isolates were identified as various species of Aspergillus. Phytases from these fungi could be utilized as a feed additive in poultry and swine industries.
  • 16S rRNA gene-based identification of microbiota associated with the parthenogenetic troglobiont sand fly Deanemyia maruaga (Diptera, Psychodidae) from central Amazon, Brazil Environmental Microbiology

    Sousa, Katianne Barbosa Alves de; Silva, Túllio Romão Ribeiro da; Alencar, Ronildo Baiatone; Baton, Luke Anthony; Naveca, Felipe Gomes; Shimabukuro, Paloma Helena Fernandes

    Abstract in English:

    Bacteria associated with the parthenogenetic troglobiont sand fly Deanemyia maruaga were characterized by sequencing cloned 16S rDNA PCR products. Eleven novel partial 16S rDNA sequences, with varying degrees of similarity to Actinobacteria, were identified. None of the sequences identified had homology to those known from parthenogenesis-inducing bacteria.
  • Diversity of the candidate phylum Poribacteria in the marine sponge Aplysina fulva Environmental Microbiology

    Hardoim, C.C.P.; Cox, C.J.; Peixoto, R.S.; Rosado, A.S.; Costa, R.; Elsas, J.D. van

    Abstract in English:

    Poribacterial clone libraries constructed for Aplysina fulva sponge specimens were analysed with respect to diversity and phylogeny. Results imply the coexistence of several, prevalently "intraspecific" poribacterial genotypes in a single sponge host, and suggest quantitative analysis as a desirable approach in studies of the diversity and distribution of poribacterial cohorts in marine sponges.
  • Human coronavirus ocurrence in different populations of Sao Paulo: a comprehensive nine-year study using a pancoronavirus RT-PCR assay Genetics And Molecular Microbiology

    Cabeça, Tatiane K.; Passos, Ana Maria; Granato, Celso; Bellei, Nancy

    Abstract in English:

    Human coronaviruses (HCoVs) are considered one of the most common respiratory viruses associated with respiratory tract illnesses. An emergent human coronavirus was identified as the causal agent of an epidemic of severe acute respiratory syndrome (SARS) during 2002-2003. The severity of the disease combined with its rapid spread requires the continuous surveillance of coronaviruses in worldwide populations. Epidemiological and clinical data of HCoVs infectious in the Brazilian population are scarce and restricted to one or two groups of patients. Our study aimed to investigate retrospectively the presence of HCoVs in different populations of São Paulo presenting acute respiratory tract infections (ARIs) during the years of 2001-2010. A pancoronavirus RT-PCR was performed in this study. Coronaviruses were detected in 126 (11.5%) of 1,087 specimens. Peaks detection frequency was observed during 2002-2004 and 2008-2009, with the highest detection in 2008. The prevalence of HCoVs was higher among children with heart diseases (24.6%), patients under stem cell transplantation program (24.3%) and renal transplanted patients (20.2%). Coryza, cough and fever were the most common symptoms at presentation of positive cases and wheezing, a lower respiratory tract infection symptom was reported by 12% of the total, and 27% of high at-risk patients. HCoVs may have an important role among patients with underlying conditions and transplanted ones.
Sociedade Brasileira de Microbiologia USP - ICB III - Dep. de Microbiologia, Sociedade Brasileira de Microbiologia, Av. Prof. Lineu Prestes, 2415, Cidade Universitária, 05508-900 São Paulo, SP - Brasil, Ramal USP 7979, Tel. / Fax: (55 11) 3813-9647 ou 3037-7095 - São Paulo - SP - Brazil
E-mail: bjm@sbmicrobiologia.org.br