Occurrence of Staphylococcus aureus in raw milk produced in dairy farms in São Paulo state, Brazil

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

Occurrence of coagulase-positive Staphylococcus in various food products commercialized in Botucatu, SP, Brazil and detection of toxins from food and isolated strains

The aim of this work was to assess the microbiological quality of commercialized desserts, sandwiches and finger food in Botucatu, SP, for human consumption. A total of 172 food samples were analyzed for fecal coliforms and coagulase-positive Staphylococcus and 69 (40.1%) were in disagreement with the standards established by Decree No. 12 (Brazilian Food Sanitation Standard, 2001). Coagulase-positive Staplylococcus was isolated from 26 (15.1%) samples. Toxins were not isolated directly from foods but 27 (54%) coagulase-positive Staphylococcus strains were enterotoxigenic, and toxin type C was the most frequently detected. These results suggest that these products may act as an important vehicle of transmission for well-established pathogens. (c) 2006 Elsevier Ltd. All rights reserved.

High Incidence of Enterotoxin D Producing Staphylococcus spp. in Brazilian Cow's Raw Milk and Its Relation with Coagulase and Thermonuclease Enzymes

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

PCR detection of staphylococcal enterotoxin genes in Staphylococcus aureus strains isolated from raw and pasteurized milk

Milk is considered a nutritious food because it contains several important nutrients including proteins and vitamins. Conversely, it can be a vehicle for several pathogenic bacteria such as Staphylococcus aureus. This study aimed to analyze the frequency of genes encoding the staphylococcal enterotoxins (SEs) SEA, SEB, SEC, SED, SEE, SEG, SEH, SEI and SEJ in S. aureus strains isolated from raw or pasteurized bovine milk. S. aureus was found in 38 (70.4%) out of 54 raw milk samples at concentrations of up to 8.9 X 10(5) CFU/ml. This microorganism was present in eight samples of pasteurized milk before the expiration date and in 11 samples analyzed on the expiration date. of the 57 strains studied, 68.4% were positive for one or more genes encoding the enterotoxins, and 12 different genotypes were identified. The gene coding for enterotoxin A, sea, was the most frequent ( 16 strains, 41%), followed by sec (8 strains, 20.5%), sed (5 strains, 12.8%). seb (3 strains. 7.7%) and see (2 strains, 5.1%). Among the genes encoding the other enterotoxins, seg was the most frequently observed (11 strains. 28.2%), followed by sei (10 strains) and seh and sej (3 strains each). With the recent identification of new SEs, the perceived frequency of enterotoxigenic strains has increased. suggesting that the pathogenic potential of staphylococci may be higher than previously thoughts however, further studies are required to assess the expression of these new SEs by S. aureus. and their impact in foodborne disease. The quality of Brazilian milk is still low. and efforts from the government and the entire productive chain are required to attain consumer safety. (C) 2008 Elsevier B.V. All rights reserved.

Occurrence of toxigenic Escherichia coli in raw milk cheese in Brazil

Pesquisou-se a ocorrência de Escherichia coli toxigênica, em queijo produzido com leite não pasteurizado, na Região Centro Oeste do Brazil. Foram utilizados 50 queijos adquiridos em diferentes supermercados. As amostras isoladas foram classificadas por sorogrupo, avaliadas em relação à sensibilidade para 13 agentes antimicrobianos e submetidas à reação em cadeia da polimerase para a presença de genes característicos de E. coli verotoxigênica (VTEC) e enterotoxigênica (ETEC). E. coli foi recuperada em 48(96,0%) dos queijos. Foram identificados os sorogrupos O125 (6,0%), O111 (4,0%), O55 (2,0%) e O119 (2,0%). Três (6,0%) amostras de E. coli foram classificadas como VTEC e uma (2,0%) como ETEC. Os maiores índices de resistência foram verificados para: cefalotina (60,0%), ácido nalidíxico (40,0%), doxiciclina (33,0%), tetraciclina (31,0%) e ampicilina (29,0%).

IDENTIFICAÇÃO DOS GENES QUE CODIFICAM PARA A ENTEROTOXINA TERMOLÁBIL LT-II em AMOSTRAS DE ESCHERICHIA COLI ISOLADAS DE BEZERROS COM DIARRÉIA NA REGIÃO DE JABOTICABAL, SP, BRASIL

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

Evaluation of survival of Staphylococcus aureus and Clostridium botulinum in charqui meats

Charqui meats were prepared in laboratory conditions in order to carry out experiments to observe the possibility of development of enterotoxigenic Staphylococcus aureus and Clostridium bottilinum proteolytic type B spores and their toxins. Results demonstrated that the harsh processing conditions, high salt concentration, relative high temperature, a, values, inhibited the growth of both bacteria. Under our experimental conditions, S. aureus would survive throughout the sequence of salting steps i.e. brine followed by rock salting and the sunshine drying step. However, at final a(w) value of 0.70-0.75 would create conditions to inhibit its development. The other experiment revealed that C. botulinum spores germination also was impaired because of these low a(w) values. Under these conditions, charqui meats revealed to be safe products in relation to toxins from both enterotoxigenic S. aureus and C. botulinum. (C) 2003 Elsevier B.V. Ltd. All rights reserved.

Virulence factors in Escherichia coli strains isolated from pigs in the Ribeirao Preto region, State of Sao Paulo, Brazil.

Three-hundred faecal swabs were obtained from pigs with diarrhoea in farms located in different areas of the Ribeirao Preto region in the State of Sao Paulo. One-hundred Escherichia coli strains were isolated and tested for production of thermolabile (TL) and thermostable (STRa and STb) enterotoxins, and for the presence of colonization factors F4, F5 and F6. The strains were also tested for sensitivity to 14 antibiotics and chemotherapeutic agents. Twenty-four Escherichia coli strains produced enterotoxin STb, 5 produced LT and 3 produced STa. In the mannose-resistant haemagglutination reaction, one strain reacted positively with sheep, chicken, horse and human red blood cells and another reacted positively with guinea pig, sheep, chicken, horse and human red cells. However, both strains were negative for colonization factors F4, F5 and F6 when submitted to the slide agglutination test. All Escherichia coli strains were resistant to at least one antibiotic, the highest percentages being obtained for resistance to penicillin, tetracycline and cephalotin. In addition to the importance of the virulence factors normally encountered in enterotoxigenic Escherichia coli strains from pigs, the present results show the possible existence of new colonization factors other than F4, F5 and F6 participating in E. coli-induced pigs colibacillosis in the Ribeirao Preto region.

Espectro de agentes etiológicos associados a surtos de doenças transmitidas por alimentos em núcleos receptores turísticos de três regiões geográficas do Estado de São Paulo

Foodborne and waterborne diseases are spread by the consumption of food or water contaminated with bacteria and/or their toxins, viruses, parasites or chemicals. The aim of the research reported here was to establish the spectrum of etiologic agents of foodborne outbreaks at 15 tourist resorts in three geographic regions of the State of Sao Paulo (Brazil). The study was based on the cases reported to the Epidemic Surveillance Center (CVE) of the Public Health Authority of the State of São Paulo (SES), from 2002 to 2005. The tourist centers were chosen at random in three regions of the state (Capital, Interior and Coast) and offered the following attractions: events, agribusiness, cultural history, shopping, town center, gastronomy, health and leisure, sun and sea. Among the bacteria, the results showed that Salmonella spp. were most frequently associated with outbreaks, followed by Shigella spp., enterotoxigenic Escherichia coli, Staphylococcus aureus, Clostridium perfringens, Bacillus cereus and Campylobacter spp. Viruses (Rotavirus and Hepatitis A) played a part in many of the cases, while the frequency of parasites and worm infestations was low in the foodborne disease outbreaks at these resorts. The mixed foods (rice, beans, liver, potatoes, barbecue, juice), fish and poultry were the three commonest vehicles implicated in the outbreaks.

Detection of enterotoxin A in coagulase-negative staphylococci isolated from nutrition students

Background: Staphylococcus is a clinically important genus because of its capacity to produce enterotoxins and to cause food poisoning. Staphylococci are the most frequent microorganisms of the skin and mucosal microbiota, with an estimated 20 to 40% of individuals carrying these bacteria on their hands or nose. Since nutrition professionals are involved in the handling and preparation of foods and are possible carriers of these bacteria, the objective of this study was to investigate the presence of Staphylococcus on the hands and in the nasal fossae of undergraduate nutrition students and to determine the enterotoxigenic capacity of these microorganisms. Methods and Findings: A total of 201 strains were isolated from the hands and nose of 61 nutrition students. Of these, 180 (89.5%) were identified as coagulasenegative staphylococci and 21 (10.5%) as S. aureus. Thirty-seven (18.4%) Staphylococcus isolates were producers of enterotoxin A. Toxin production was detected in 5 (19%) of the S. aureus isolates and in 31 (17.2%) of the coagulase-negative staphylococci. Conclusions: This study demonstrated a large number of enterotoxin-producing staphylococci on the hands and nose of nutrition students and professionals involved in the handling and preparations of foods. These findings indicate the need for adequate hygiene measures to prevent food poisoning. © iMedPub.

Enterotoxinas de Staphylococus coagulase positiva e negativa isoladas das fossas nasais e mãos de manipuladores de alimentos

Pós-graduação em Medicina Veterinária - FMVZ

Detecção molecular de Staphylococcus aureus e de suas toxinas no leite de tanque de rebanhos bovinos, em condições de refrigeração e sob temperatura ambiente

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

Bactérias do grupo do Bacillus cereus em leite e estudo enterotoxigênico das cepas isoladas

Pós-graduação em Medicina Veterinária - FCAV

Escherichia coli potencialmente patogênica isoladas de ovinos saudáveis criados extensivamente e de carcaças em matadouros-frigoríficos no Estado de São Paulo

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

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