Detection of enterotoxin and toxic shock syndrome toxin 1 genes in Staphylococcus, with emphasis on coagulase-negative staphylococci

The detection of staphylococcal enterotoxins is decisive for the confirmation of an outbreak and for the determination of the enterotoxigenicity of strains. Since the recognition of their antigenicity, a large number of serological methods for the detection of enterotoxins in food and culture media have been proposed. Since immunological methods require detectable amounts of toxin, molecular biology techniques represent important tools in the microbiology laboratory. In the present study, polymerase chain reaction (PCR) was used to identify genes responsible for the production of enterotoxins and toxic shock syndrome toxin 1 (TSST-1) in S. aureus and coagulase-negative staphylococci (CNS) isolated from patients and the results were compared with those obtained by the reverse passive latex agglutination (RPLA) assay. PCR detection of toxin genes revealed a higher percentage of toxigenic S. aureus strains (46.7%) than the RPLA method (38.3%). Analysis of the toxigenic profile of CNS strains showed that 26.7% of the isolates produced some type of toxin, and one or more toxin-specific genes were detected in 40% of the isolates. These results suggests the need for further studies in order to better characterize the pathogenic potential of CNS and indicate that attention should be paid to the toxigenic capacity of this group of microorganisms.

The role of virulence factors in the outcome of staphylococcal peritonitis in CAPD patients

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Phenotype characterization of Staphylococcus species strains isolated from buffalo (Bubalus bubalis) milk

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Staphylococcus spp., Enterobacteriaceae and Pseudomonadaceae oral isolates from Brazilian HIV-positive patients. Correlation with CD4 cell counts and viral load

The aim was to evaluate the presence of Staphylococcus spp., Enterobacteriaceae and Pseudomonadaceae in the oral cavities of HIV-positive patients. Forty-five individuals diagnosed as HIV-positive by ELISA and Western-blot, and under anti-retroviral therapy for at least 1 year, were included in the study. The control group constituted 45 systemically healthy individuals matched to the HIV patients to gender, age and oral conditions. Oral rinses were collected and isolates were identified by API system. Counts of microorganisms from HIV and control groups were compared statistically by a Mann-Whitney test (alpha = 5%). The percentages of individuals positive for staphylococci were similar between the groups (p = 0.764), whereas for Gram-negative rods, a higher percentage was observed amongst HIV-positive (p = 0.001).There was no difference in Staphylococcus counts between HIV and control groups (p = 0.1008). Counts were lower in the oral cavities of patients with low viral load (p = 0.021), and no difference was observed in relation to CD4 counts (p = 0.929). Staphylococcus aureus was the most frequently isolated species in HIV group, and Staphylococcus epidermidis was the prevalent species in the control group. Significantly higher numbers of enteric bacteria and pseudomonas were detected in the oral cavities of the HIV group than in the control (p = 0.0001). Enterobacter cloacae was the most frequently isolated species in both groups. Counts of enteric bacteria and pseudomonas were significantly lower in patients with low CD4 counts (p = 0.011); however, there was no difference relating to viral load. It may be concluded that HIV group showed greater species diversity and a higher prevalence of Enterobacteriaceae/Pseudomonadaceae. (C) 2011 Elsevier Ltd. All rights reserved.

Staphylococcal carriage and antibodies to toxic shock syndrome toxin 1 in Brazilian women

A study of 215 women from different socioeconomic backgrounds in Botucatu, Brazil, was conducted to reveal possible clues why toxic shock syndrome (TSS) is seldom diagnosed in Brazil. Of the 215 women, 79 were colonized with Staphylococcus aureus either in the nasal passages and/or in the vaginal area, which is comparable to the colonization of individuals in the developed countries Thirteen of the women were colonized with S. aureus that produced toxic shock syndrome toxin-1 (TSST-1), the toxin responsible for the majority of cases of TSS. Eleven strains produced enterotoxin B, the only enterotoxin implicated in TSS, primarily in non-menstrual TSS. Enterotoxin A was produced by 15 strains and is commonly associated with the production of TSST-1, but has not been implicated in TSS. Seven strains produced enterotoxin D and one strain produced enterotoxin C, but these have not been implicated in TSS. Only 9 women used tampons which may be a major reason for the lack of menstrual TSS in Brazil, Only two of the 49 women whose sera were examined for the presence of antibodies to TSST-1 had no or very low antibody titers, the major protection against the development of TSS, both menstrual and non-menstrual TSS. This is a lower percentage than has been observed in the developed countries. Although another possibility for the lack of TSS in Brazil is the failure to recognize the disease, however, the results of this limited study indicate the importance of low usage of tampons and the high percentage of individuals with antibodies to TSST-1. The socioeconomic backgrounds of the participants were of little significance.

Caracterização do perfil clonal, fatores de virulência e determinação da resistência em Staphylococcus spp. isolados de leite ovino

Pós-graduação em Biologia Geral e Aplicada - IBB

Determinação do perfil toxigênico em Staphylococcus aureos e estafilococos coagulase-negativa isolados de recém-nascidos pela técnica de RT-PCR

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Caracterização molecular de Staphylococcus sp, isolados de leite de vacas com mastite, em diferenes regiões do estado de São Paulo

Pós-graduação em Biologia Geral e Aplicada - IBB

Importância da virulência nas linhagens de Staphylococcus spp. em portadores e no risco de peritonites em diálise peritoneal ambulatorial

Pós-graduação em Fisiopatologia em Clínica Médica - FMB

Diversity of Staphylococcus species and prevalence of enterotoxin genes isolated from milk of healthy cows and cows with subclinical mastitis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Potentiated Electron Transference in alpha-Ag2WO4 Microcrystals with Ag Nanofilaments as Microbial Agent

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Staphylococcus sp na produção primária de leite: aspectos de saúde pública

Staphylococcus is one of the more important causes of the called Foodborne Disease(FD), being that from the 40 species described from genus, the more important is Staphylococcus aureus. During years believed that the S. aureus was the only specie from genus able to produce enterotoxins, responsable for the clinical frame in humans, but latest studies report the isolation of other species both positive coagulase (PC) as negative with enterotoxigenic potential. The symptoms of this intoxication appear after a short period of incubation (2-6 hours) and usually characterized by nausea, vomits, abdominal ache, diarrhea, and rarely is fatal. For the toxin to be formed in food is necessary that bacteria population to be at least 105 UFC/g, being that such toxins characterized by presenting great resistance front of gastrointestinal proteases and of homemade termical treatment. Among the main foods that might carry the microorganism, the milk and its derivatives have highlights. The contamination of the product might happen as from the milk from cows with clinical and/or subclinical mastitis, as the Staphylococcus genus is one of the main agents etiologic from this disease, equipments utensils badly sanitized equipments and utensils and from the manipulators. The control of these factors configures as fundamental condition for the achievement of a safe, quality product, which doesn’t offer risk to the consumers

Rheological characterisation and effect of abiotic factors on the antimicrobial efficacy of chitosan-based hidrogels containing alpha-hydroxy acids

The aim of this study was to investigate the rheological properties and antibacterial efficacy of chitosan/ alpha-hydroxy acids (lactic acid and glycolic acid) and cellulose polymers, both in hydrogels, in order to produce a formulation with improved activity against Propionibacterium acnes and Staphylococcus aureus, which can potentially be used in the treatment of acne. The rheological characterisation of the hydrogels was examined using continuous shear and viscoelastic creep. The antibacterial activities of formulations were performed by the well diffusion and broth microdilution. The hydrogels formulated with only chitosan showed pseudoplastic behavior while the chitosan hydrogels with cellulose polymers presented viscoelastic properties. The antibacterial activity was proportional to AHA and chitosan concentration. It was enhanced at low pH values and with high molecular weight chitosan and did not change with the incorporation of two cellulose polymers. The antibacterial mechanism of chitosan has currently been hypothesized as being related to surface interference. The results show that chitosan - based hydrogels containing AHA and cellulose polymers are viscoelastic,indicating good applicability onto the skin, and they present bacterial activity under various experimental conditions.

Ocorrência de Staphylococcus sp. em água utilizada em propriedades leiteiras do Estado de São Paulo

Com o objetivo de verificar o papel da água utilizada durante a produção do leite como via de transmissão de Staphylococcus sp., fez-se a contagem de Staphylococcus coagulase negativa e Staphylococcus aureus nas amostras de água das fontes, dos reservatórios e dos estábulos de 30 propriedades leiteiras situadas na região Nordeste do Estado de São Paulo. As maiores ocorrências de isolamentos (10,0 e 16,6%) e os maiores valores médios (4,3×10(4) e 2,5×10(4)) de contagens desses microrganismos foram encontrados nas amostras de água dos estábulos utilizada na obtenção de leite. Estes resultados são importantes pois evidenciam a possibilidade de contaminação do leite ou dos animais por cepas patogênicas.

Phenolic compounds in leaves of Alchornea triplinervia: anatomical localization, mutagenicity, and antibacterial activity

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)