RESUMO Em 2004 ocorreu um surto de diarreia aguda no Estado de Pernambuco, Brasil. Setenta por cento (14 dos 20) dos sobrenadantes de cultura de Aeromonas caviae, isoladas neste episódio induziram acúmulo de líquido em testes de alça ligada de intestino de coelhos, assim como em teste em camundongos recém-nascidos. Os mesmos sobrenadantes mostraram também atividade citotóxica em células de Vero e Caco-2, mas não em células HeLa e HEp2. As atividades enterotóxicas e citotóxicas mantiveram-se mesmo após o aquecimento a 100 ºC dos sobrenadantes de cultura. Este trabalho revela a expressão de um provável fator diarreiogênico: uma enterotoxina-citotóxica termo-estável, produzida por A. caviae que pode ser associada ao surto de diarreia ocorrido no Brasil. Atualmente estamos purificando esta enterotoxina termo-estável, com o objetivo de elucidar seu papel como fator de virulência na diarreia causada por A. caviae.

SUMMARY In the present study enterotoxic and cytotoxic activities of twenty Aeromonas caviaestrains were examined. They originated from fecal specimens of patients with acute diarrhea during an outbreak in Brazil in 2004. Culture supernatants of fourteen strains (70%) caused fluid accumulation in rabbit ileal intestinal loops and in suckling mice assays, and also showed a cytotoxic activity in Vero and Caco-2 cells. The enterotoxic and cytotoxic factors were heat-stable after culture supernatants treatment at 100 ºC. The results revealed that A. caviaestrains produce a putative diarrheagenic virulence factor, a heat-stable cytotoxic enterotoxin that could be linked to the diarrhea outbreak that took place in Brazil.

Ten out of fifty fresh and refrigerated samples of shrimp (Litopenaeus vannamei) collected from retailers in Natal (Rio Grande do Norte, Northeastern Brazil) tested positive for Vibrio parahaemolyticus. The Kanagawa test and multiplex PCR assays were used to detect TDH and TRH hemolysins and the tdh, trh and tlh genes, respectively. All strains were Kanagawa-negative and tlh-positive. Antibiotic susceptibility testing was done for seven antibiotics by the agar diffusion technique. Five strains (50%) presented multiple antibiotic resistance to ampicillin (90%) and amikacin (60%), while two strains (20%) displayed intermediate-level resistance to amikacin. All strains were sensitive to chloramphenicol. Intermediate-level susceptibility and/or resistance to other antibiotics ranged from 10 to 90%, with emphasis on the observed growing intermediate-level resistance to ciprofloxacin. Half our isolates yielded a multiple antibiotic resistance index above 0.2 (range: 0.14-0.29), indicating a considerable risk of propagation of antibiotic resistance throughout the food chain.

INTRODUÇÃO: Listeria monocytogenes é o agente etiológico da listeriose, doença de origem alimentar que acomete principalmente grávidas, pacientes imunodeprimidos e idosos. O tratamento primário é a associação de ampicilina a um aminoglicosídeo além de outros, em segunda escolha, representados por cloranfenicol, eritromicina, tetraciclina e rifampicina. O presente estudo teve como objetivo analisar o perfil de susceptibilidade aos antimicrobianos de amostras de origem humana isoladas nas últimas quatro décadas. MÉTODOS: Foram selecionadas 68 cepas provenientes de casos clínicos humanos ocorridos em diferentes regiões do país no período de 1970-2008. A susceptibilidade aos antimicrobianos testados foi determinada através dos critérios estabelecidos por Soussy pelo método de Kirby-Bauer e a concentração mínima inibitória realizada através do E-Test. RESULTADOS: A amostragem constituiu-se de 68 cepas, isoladas principalmente de líquido cefalorraquidiano, e hemocultura no período, pertencentes ao Laboratório de Zoonoses Bacterianas/LABZOO/Fiocruz. O sorovar L4b (60,3%) foi o mais prevalente, seguido do sorovar 1/2a (20,6%), 1/2b (13,2%) e aqueles mais raros representados por 1/2c, 3b e 4ab (5,9%). Todas as cepas foram sensíveis à ampicilina, cefalotina, eritromicina, gentamicina, teicoplanina e vancomicina. Apenas uma cepa (1,5%) apresentou resistência à rifampicina, enquanto duas (3%) foram resistentes à associação de sulfametoxazol-trimetoprim. CONCLUSÕES: Apesar de o estudo ter demonstrado uma baixa prevalência de amostras resistentes aos antimicrobianos indicados na terapêutica da listeriose humana, o sistema de monitoramento do perfil de resistência antimicrobiana é de extrema importância para a orientação do tratamento adequado, principalmente nas infecções em pacientes imunocomprometidos.

INTRODUCTION: Listeria monocytogenes is the causative agent of listeriosis, a foodborne illness that affects mainly pregnant women, the elderly and immunocompromised patients. The primary treatment is a combination of ampicillin with an aminoglycoside, in addition to a second-choice drug represented by chloramphenicol, erythromycin, tetracycline and rifampicin. The aim of this study was to analyze the antimicrobial susceptibility profile of strains isolated from human sources in the last four decades. METHODS: Sixty-eight strains were selected from the culture collection of the Laboratory of Bacterial Zoonoses/LABZOO/FIOCRUZ isolated in different regions of Brazil from 1970 to 2008 and primarily isolated from cerebrospinal fluid and blood culture. Susceptibility tests to antimicrobials drugs were evaluated using the criteria established by Soussy using the Kirby-Bauer method and E-Test strips were used to determine the minimum inhibitory concentration (MIC). RESULTS: Among the strains tested, serovar L4b (60.3%) was the most prevalent, followed by serovar 1/2a (20.6%), 1/2b (13.2%) and the more uncommon serovars 1/2c, 3b and 4ab (5.9%). All strains were susceptible to ampicillin, cephalothin, erythromycin, gentamicin, teicoplanin and vancomycin. Only one strain (1.5%) showed resistance to rifampin, and two (3%) were resistant to trimethoprim-sulfamethoxazole. MICs with values up to 2μg/ml reinforce the need for microbiological surveillance. CONCLUSIONS: The study demonstrated low prevalence of strains resistant to the antimicrobial drugs indicated in the treatment of human listeriosis. Monitoring antimicrobial resistance profile is still very important to determine adequate treatment, especially in immunocompromised patients.

Thirty water samples were collected, at two week intervals, from the estuary of the River Cocó. The aim was to characterize the presence, distribution and types of Aeromonas spp, in the estuary of the River Cocó, Ceara, Brazil (03º46'28.83''S e 38º26'36.52''S). Aeromonas were identified in 19 (63%) samples analyzed by plating and CFU counts. Presence/absence tests were positive for 11 (37%) of the samples resulting in the detection of Aeromonas in a total of 23 (77%) of samples. CFU counts varied from < 10 to 1.4 x 10(4) CFU mL-1 . From the isolated strains seven species of Aeromonas were identified: A. caviae (29/69), A. veronii bv. sobria (13/69), A. veronii bv. veronii (8/69), A. trota (6/69), A. media (5/69), A. sobria (4/69) and A. hydrophila and Aeromonas sp. (2/69). Of the 38 strains tested, 23 (60%) showed resistance to at least one of the eight antimicrobials. Multiple resistance to antibiotics was observed in A. caviae, A. media, A. sóbria and A. veronii bv. sobria. Aeromonas caviae showed the highest multiple resistance, being resistant to four antibiotics. The presence of those microorganisms may contribute to the occurrence of gastroenteritis, mainly in children, since they are considered opportunists.

Aeromonas spp é reconhecida como patogênica para o homem após o consumo de água e alimentos contaminados. Na presente investigação, foram avaliadas 2.323 amostras de swabs retais de neonatos hospitalizados no Rio de Janeiro objetivando o isolamento de Aeromonas. As amostras foram coletadas e enviadas ao Laboratório de Referência Nacional de Cólera e outras enteroinfecções bacterianas, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz. Os swabs foram submetidos ao enriquecimento em água peptonada alcalina adicionada de 1% de cloreto de sódio (NaCl) e água peptonada alcalina adicionada de 3% de NaCl (37ºC/18-24h) e semeadas em agar seletivo para Pseudomonas aeromonas (Agar GSP). Foram isoladas 56 cepas de Aeromonas assim distribuídas: Aeromonas caviae (42,8%), Aeromonas media (25%), Aeromonas veronii biogrupo sobria (10,7%), Aeromonas hydrophila (9%), Aeromonas veronii biogrupo veronii (5,3%), Aeromonas sobria (1,8%), Aeromonas jandaei (1,8%), Aeromonas schubertii (1,8%) e Aeromonas sp (1,8%). Foi observada resistência a uma ou mais drogas antimicrobianas em 26,8% das cepas. Considerando a relevância de Aeromonas torna-se urgente alertar sobre sua importância para o controle de infecções hospitalares.

Aeromonas spp is recognized as pathogenic to humans after consumption of contaminated water and food. In the present investigation, 2,323 rectal swab samples from newborns hospitalized in Rio de Janeiro were evaluated with a view to isolating Aeromonas. The samples were collected and sent to the national reference laboratory for cholera and other bacterial intestinal infections, at the Oswaldo Cruz Institute of the Oswaldo Cruz Foundation. The swabs were subjected to enrichment in alkaline peptonated water with the addition of 1% sodium chloride (NaCl) and alkaline peptonated water plus 3% NaCl (37°C/18-24h) and were streaked onto agar that was selective for Pseudomonas-Aeromonas (GSP Agar). Fifty-six Aeromonas strains were isolated, distributed as follows: Aeromonas caviae (42.8%), Aeromonas media (25%), Aeromonas veronii biogroup sobria (10.7%), Aeromonas hydrophila (9%), Aeromonas veronii biogroup veronii (5.3%), Aeromonas sobria (1.8%), Aeromonas jandaei (1.8%), Aeromonas schubertii (1.8%) and Aeromonas sp (1.8%). Resistance to one or more antimicrobial drugs was observed in 26.8% of the strains. Considering the importance of Aeromonas, there is an urgent need to warn about this in relation to nosocomial infection control.

No primeiro semestre de 2004, ocorreu um surto de diarréia em São Bento do Una, Pernambuco, registrando-se 2.170 casos. Nas 582 coproculturas realizadas, 145 (25%) revelaram um enteropatógeno bacteriano, destacando 114 casos (19,5%) com a participação de Aeromonas, representadas por Aeromonas caviae (57/9,8%), Aeromonas veronii biovar sobria (23/3,9%), Aeromonas veronii biovar veronii (15/2,6%) e outras espécies (19/3,2%). Nos 31 episódios restantes (5,3%), foram detectados: V. cholerae O1 Ogawa toxigênico (18/3,1%), Salmonella spp (8/1,4%), Shigella spp (3/0,5%) e Vibrio cholerae não O1/não O139 (2/0,3%).

An acute diarrhea outbreak, with 2170 cases, was described during January to July, 2004, in São Bento do Una, Pernambuco. 582 stools were examined and an enteric pathogen was recovered in 25% (145 patients). Aeromonas species were the most frequent (114-19.5%) and the main isolates were Aeromonas caviae (57-9.8%), Aeromonas veronii biovar sobria (23-3.9%), Aeromonas veronii biovar veronii (15-2.6%) and other species (19-3.2%). The other isolated enteropathogens were Vibrio cholerae O1-Ogawa toxigenic (18-3.1%), Salmonella spp (8-1.4%), Shigella spp (3-0.5%) and Vibrio cholerae non-O1/non-O139 (2-0.3%).

A análise fenotípica de 255 amostras do gênero Listeria isoladas de material clínico humano, tanto de indivíduos doentes (220-86,3%), como de aparentemente normais (35-13,7%) de várias regiões do país e colecionadas no período de 1969 a 2000, permitiu caracterizar a distribuição de sorovares de Listeria monocytogenes. Nas faixas etárias de 0 a 10 e de 41 a 60 anos, predominaram os isolamentos de líquido cefalorraquidiano sobre os de sangue, incluindo dos transplantados renais. Somente dos hemocultivos foi possível detectar os sete sorovares de Listeria monocytogenes. No cômputo geral, o sorovar 4b foi o mais incidente (154-60,3%) secundado por ¹/2 a (74-29%) nos três decênios considerados, além de ocorrerem em quase todas as regiões do país. Os dados deste estudo evidenciaram a circulação de L. monocytogenes na espécie humana, provocando quadros graves de meningite e septicemia, bem como, revelando a figura do portador assintomático, razão pela qual são recomendadas novas investigações bacteriológicas, subsidiadas por análises clínico-patológicas e epidemiológicas.

Using phenotype techniques, characterization was realized of species and serovars of 255 strains of Listeria isolated from human material: 220-86.3% were from patients with possible invasive disease, while 35-13.7% were from colonized healthy individuals. The strains were collected in several regions of Brazil from 1969-2000. In individuals aged 0-10 or 41-60 years old Listeria monocytogenes was isolated more often in cerebral spinal fluid than in blood cultures, including samples from renal transplant recipients. All Listeria monocytogenes serovars were detected in blood culture strains. The predominant serovars characterized were 4b (154-60.3%) and ¹/2 a (74-29%). In this study, Listeria monocytogenes causing invasive diseases, such as meningitis or septicemia, or colonizing individuals, were identified. Consequently further studies focusing on clinical and pathological as well as epidemiological issues, including risk factors associated with foodborne transmission should be pursued.

A análise fenotípica de 246 amostras do gênero Listeria isolados de animais portadores e doentes, provenientes de três regiões do país, colecionadas no período de 1971 a 2000, permitiu caracterizar as espécies e sorovares prevalentes. Dentre os animais predominaram os espécimes fecais de bovinos normais (217 amostras, 88,2%), em contraposição aos 29 isolados (11,7%) de Listeria de animais doentes, apresentando comprometimento do sistema nervoso central (15 amostras, 6,0%) e outras localizações sistêmicas (14 amostras, 5,6%). Quanto às espécies e sorovares, predominaram L. innocua 6a e não tipável (140 amsotras, 56,9%) e L.monocytogenes 4a (37 amostras, 15,0) e 4b (22 amostras, 8,9%) principalmente nas fezes de bovinos hígidos e nos animais doentes, L. monocytogenes sorovares 4b (14 amostras, 5,6%) com destaque nos ruminantes e 1a (8 amostras, 3,2%) incidindo nas outras espécies animais (roedores e canídeos) e tendo localizações prevalentes em áreas distintas ao sistema nervoso central.

Two hundred fourty-six strains of the genus Listeria were isolated from sick and clinically healthy animals, collected in three different regions of Brazil during 1971-2000. About 88.2% (217 cultures) yielded Listeria species from faecal specimens of healthy cattle and 29 strains (11.7%) were isolated from sick animals: 15 (6.0%) from central nervous system (CNS) and 14(5.6%) were from otherwise sterile sites. Phenotyping techniques were used to characterize the Listeria isolates. The commonest were L. innocua 6a and non-typable (140/56.9%), L. monocytogenes 4a (37/15.0%) and 4b (22/8.9%), originated mainly from stools of healthy cattle. From sick animals the predominant species and serovars were L. monocytogenes 4b (14/5.6%), and the higher incidence was observed in ruminants (12/4.8%) and 8/3.2% of the serovar 1a from other animal species (rodents and canines) mainly isolated from CNS samples.

O isolamento de Burkholderia pseudomallei, de meio ambiente e de espécimes clínicos, foi raramente registrado na América do Sul, particularmente no Brasil. Este relato descreve o caso de melioidose em um paciente de 10 anos de idade, de área rural do estado do Ceará (Tejuçuoca). As hemoculturas foram positivas e as análises dos testes bioquímicos e de susceptibilidade aos antimicrobianos do isolado foram indicativos para a identificação de B. pseudomallei. A fonte de contaminação foi obscura, uma vez que as análises microbiológicas de solo e água no tanque foram negativas.

Burkholderia pseudomallei has rarely been isolated from environmental and clinical specimens in South America, particularly, in Brazil. This report describes a case of melioidosis with fulminant sepsis in a 10 year old boy, from rural area, in Tejuçuoca, State of Ceará, Brazil. Blood samples were positive and, through the analysis of results from biochemical tests and of drugs susceptibility profile, identified this gram-negative bacillus as B. pseudomallei. The contamination source remains obscure in this case, as soil and water tanks samples submitted to microbiological analyses did not indicate the presence of B. pseudomallei.