Abstract in English:BACKGROUND The link between Candida albicans and diabetes mellitus is well-acknowledged, but incompletely elucidated. OBJECTIVES The purpose of this study is to assess the growth rate of C. albicans (CA) in the presence of different concentrations of glucose and fructose, two of the main pathophysiologic and nutritionally relevant sugars in diabetic patients, in order to obtain a better understanding of the nutrient acquisition strategy and its possible relation to the hyperglycemic status of diabetic patients. METHODS The effects of different concentrations of glucose and fructose (1000 mg%, 500 mg%, 250 mg% and 100 mg% w/v) on the growth rate of CA have been studied by flow-cytometry. FINDINGS We found that glucose concentration is directly related to CA growth, which may be linked to the frequent yeast infections that occur in non-controlled diabetic patients; we also show that fructose inhibits CA growth rate. MAIN CONCLUSIONS As a consequence of our hypothesis, the study demonstrates that fructose-containing food may prevent the development of candidiasis, at least in oral sites.
Abstract in English:BACKGROUND Paleoparasitology reveals the status of parasitic infections in humans and animals in ancient times based on parasitic particles found in biological remains from archaeological excavations. This line of research emerged in Iran in 2013. OBJECTIVE The identification of parasites from Neolithic times is an attractive subject that shows the oldest origins of parasitic infections in a given geographical region. From an archaeological point of view, this archaeological site is well-known for animal domestication and agriculture in ancient Iran. METHODS In this study, soil deposited on the surface and in the pores of a dog pelvic bone was carefully collected and rehydrated using trisodium phosphate solution. FINDINGS The results showed ascarid and taeniid eggs retrieved from the biological remains of a dog excavated at the East Chia Sabz archaeological site, which dates back to the Neolithic period (8100 BC). MAIN CONCLUSION The current findings clearly illustrate the natural circulation of nematode and cestode parasites among dogs at that time. These ancient helminth eggs can also be used to track the oldest parasitic infections in the Iranian plateau and contribute to the paleoparasitological documentation of the Fertile Crescent.
Abstract in English:BACKGROUND As chronic Chagas disease does not have a definitive treatment, the development of alternative therapeutic protocols is a priority. Dipyridamole (DPY) is an alternative to counteract the pathophysiological phenomena involved in Chagas cardiomyopathy. OBJECTIVE To evaluate the therapeutic efficacy of DPY associated with nifurtimox (Nfx) in epimastigote axenic cultures and in mice with acute Chagas disease. METHODS NMRI adult male mice were divided into nine groups: three healthy and six Trypanosoma cruzi-infected groups. Mice received vehicle, Nfx or DPY, alone or combined. The doses assayed were Nfx 10 and 40 mg/kg and DPY 30 mg/kg. The treatment efficacy was evaluated by clinical, electrocardiographic, parasitological, biochemical and histopathological methods. FINDINGS In vitro, DPY and Nfx had a trypanocidal effect with IC50 values of 372 ± 52 and 21.53 ± 2.13 µM, respectively; DPY potentiated the Nfx effect. In vivo, Nfx (40 mg/kg) with or without DPY had a therapeutic effect, which was reflected in the 84-92% survival rate and elimination of parasitaemia and heart tissue amastigotes. Nfx (10 mg/kg) had a subtherapeutic effect with no survival and persistence of amastigotes, inflammation and fibrosis in heart tissue; adding DPY increased the survival rate to 85%, and all tested parameters were significantly improved. MAIN CONCLUSION DPY has a trypanocidal effect in vitro and enhances the Nfx therapeutic effect in an in vivo murine model.
Abstract in English:BACKGROUND There is a lack of straightforward tests for field application and known biomarkers for predicting leprosy progression in infected individuals. OBJECTIVE The aim was to analyse the response to infection by Mycobacterium leprae based on the reactivity of specific antigens: natural disaccharide linked to human serum albumin via an octyl (NDOHSA), a semisynthetic phenolic glycolipid-I (PGL-I); Leprosy Infectious Disease Research Institute Diagnostic-1 (LID-1) and natural disaccharide octyl - Leprosy Infectious Disease Research Institute Diagnostic-1 (NDOLID). METHODS The study population consisted of 130 leprosy cases diagnosed between 2010 and 2015 and 277 household contacts. An enzyme-linked immunosorbent assay (ELISA) was used to analyse the reactivity of antibodies against NDOHSA, LID-1 and NDOLID. The samples and controls were tested in duplicate, and the antibody titer was expressed as an ELISA index. Data collection was made by home visits with application of questionnaire and dermatological evaluation of all household contacts to identify signs and symptoms of leprosy. FINDINGS Significant differences in the median ELISA results were observed among leprosy cases in treatment, leprosy cases that had completed treatment and household contacts. Higher proportions of seropositivity were observed in leprosy cases in treatment. Seropositivity was also higher in multibacillary in relation to paucibacillary, with the difference reaching statistical significance. Lower titers were observed among cases with a longer treatment time or discharge. For household contacts, the differences according to the clinical characteristics of the leprosy index case were less pronounced than expected. Other factors, such as the endemicity of leprosy, exposure outside the residence and genetic characteristics, appeared to have a greater influence on the seropositivity. MAIN CONCLUSIONS Serologic tests could be used as auxiliary tools for determining the operational classification, in addition to identifying infected individuals and as a strategy for surveillance of household contacts.
Abstract in English:BACKGROUND Leishmanolysins have been described as important parasite virulence factors because of their roles in the infection of promastigotes and resistance to host’s defenses. Leishmania (Viannia) braziliensis contains several leishmanolysin genes in its genome, especially in chromosome 10. However, the functional impact of such diversity is not understood, but may be attributed partially to the lack of structural data for proteins from this parasite. OBJECTIVES This works aims to compare leishmanolysin sequences from L. (V.) braziliensis and to understand how the diversity impacts in their structural and dynamic features. METHODS Leishmanolysin sequences were retrieved from GeneDB. Subsequently, 3D models were built using comparative modeling methods and their dynamical behavior was studied using molecular dynamic simulations. FINDINGS We identified three subgroups of leishmanolysins according to sequence variations. These differences directly affect the electrostatic properties of leishmanolysins and the geometry of their active sites. We identified two levels of structural heterogeneity that might be related to the ability of promastigotes to interact with a broad range of substrates. MAIN CONCLUSION Altogether, the structural plasticity of leishmanolysins may constitute an important evolutionary adaptation rarely explored when considering the virulence of L. (V.) braziliensis parasites.
Abstract in English:BACKGROUND In Brazil, few studies have investigated the prevalence of infection with the precore (PC) and basal core promoter (BCP) mutants of the hepatitis B virus (HBV). OBJECTIVES This study aimed to analyse the frequency of PC and BCP mutations among patients infected with HBV and to evaluate the association between the variants and advanced hepatic disease. METHODS A total of 161 patients infected with HBV were studied. To identify PC and BCP mutations, a 501-bp fragment of HBV DNA was amplified and sequenced. FINDINGS PC and BCP regions from HBV strains were successfully amplified and sequenced in 129 and 118 cases, respectively. PC and BCP mutations were detected in 61.0% and 80.6% of the cases, respectively. The A1762T/G1764A variant was identified in 36.7% of the patients with grade 1 and 2 liver fibrosis (29/79) and in 81.8% of the patients with grade 3 and 4 liver fibrosis (9/11) (p < 0.01); in 76.9% of the patients with cirrhosis (10/13) and in 38.1% of the patients without cirrhosis (40/105) (p = 0.01); and in 77.8% of the patients with hepatocellular carcinoma (HCC) (7/9) and in 39.4% of the patients without HCC (43/109) (p = 0.03). MAIN CONCLUSIONS A high prevalence of HBV PC and BCP mutants was found. The A1762T/G1764A variant was independently associated with advanced forms of liver fibrosis, hepatic cirrhosis, and HCC.
Abstract in English:BACKGROUND Hepatitis C virus (HCV) infection is a worldwide public health problem. A characterisation of the differences in exposure sources among genders will enable improvements in surveillance actions. METHODS Exposure data were obtained for 1180 confirmed HCV cases Brazil’s mandatory reporting to epidemiological surveillance, which was directed by a reference laboratory in Rio de Janeiro, Brazil. The Chi-square test (χ2) was used to assess the associations between exposure sources and gender. The prevalence ratio (PR) was calculated for exposures that showed an association. RESULTS The results showed 57.7% cases were female, and associations with snorting drugs, sexual activity, surgery, aesthetic procedures, blood transfusions, and educational level were observed (p < 0.001). Men showed 2.53 (1.33-3.57), 4.83 (3.54-6.59), and 2.18 (1.33-3.57) times more exposure to sniffing drugs, risky sex and higher levels of education, respectively, than women. Women demonstrated 4.46 (3.21-6.21), 1.94 (1.43-2.63), and 3.10 (2.09-4.61) times more exposure to surgery, aesthetic procedures, and blood transfusions, respectively, than men. CONCLUSION Our results showed differences in risk behaviours associated with gender among HCV carriers. These data are likely to significantly influence clinical practice regarding the adoption of specific approaches for counselling and control policies to prevent the emergence of new cases and break the chain of transmission of the virus.
Abstract in English:BACKGROUND Cutaneous leishmaniasis (CL) generally presents with a single or several localised cutaneous ulcers without involvement of mucous membranes. Ulcerated lesions are susceptible to secondary contamination that may slow the healing process. OBJECTIVE This study verified the influence of non-parasitic wound infection on wound closure (epithelialisation) and total healing. METHODS Twenty-five patients with a confirmed diagnosis of CL and ulcerated lesions underwent biopsy of ulcer borders. One direct microbial parameter (germ identification in cultures) and four indirect clinical parameters (secretion, pain, burning sensation, pruritus) were analysed. FINDINGS Biopsies of ten lesions showed secondary infection by one or two microorganisms (Staphylococcus aureus, Pseudomonas aeruginosa, Enterococcus faecalis, Streptococcus pyogenes and Candida parapsilosis). “Secretion” and “burning sensation” influenced epithelialisation time but not total healing time. Positive detection of germs in the ulcer border and “pain” and “pruritus” revealed no influence on wound closure. CONCLUSIONS Our borderline proof of clinical CL ulcer infection inhibiting CL wound healing supports the need to follow antimicrobial stewardship in CL ulcer management, which was recently proposed for all chronic wounds.
Abstract in English:CC398 is a livestock-associated Staphylococcus aureus. However, it has also been isolated from humans with no previous contact with livestock. A surveillance of methicillin-resistant S. aureus colonisation among children attending public day care centres and hospitals in Niterói and Rio de Janeiro, Brazil, between 2011 and 2013, resulted in the isolation of six cases of CC398 from individuals with no previous exposure to livestock. These isolates showed a high frequency of the erm(C) gene (4/6, 66.7%) with induced resistance to clindamycin, and a relatively high frequency of SEs and lukS/lukF genes. These results suggest the emergence of a non-LA-CC398 in Brazil.
Abstract in English:In early 2016, it was suspected that there were more deaths in Pernambuco than in previous years during an epidemic of chikungunya. This study tested whether there was an increased number of deaths and, if so, whether this increase could be related to a chikungunya epidemic. Indeed, there was an increase of 4235 deaths in 2016 compared to the average of the four previous years, and the highest differences were found during the peak period of the epidemic. It was evident that not all of these deaths could be attributed to complications of chikungunya. However, considering the temporal overlap, some of these deaths may have been caused by the aggravation of pre-existing comorbidities or complications caused directly by chikungunya virus infection.