RESUMO
Staphylococcus aureus is a major bacterial pathogen involved in a wide range of diseases varying from infections to toxaemia. Staphylococcal food-poisoning syndrome is caused by ingestion of bacterial enterotoxins. These toxins are microbial superantigens and may also be virulence factors involved in staphylococcal infection. This study determined the enterotoxin types and pulsed-field gel patterns found among S. aureus isolates obtained from food handlers in community or hospital-located kitchens. Staphylococcal enterotoxin C was the most frequent enterotoxin produced. The data also suggested horizontal spread of ent genes among isolates belonging to the Brazilian epidemic MRSA clone III::B:A. A subclone of MRSA clone III::B:A was isolated from two hospital kitchen workers. This was the first report of this clone from a hospital in Teresina, Piaui State, although the presence of this MRSA clone has already been reported in six other Brazilian cities.
Assuntos
Portador Sadio/microbiologia , Enterotoxinas/biossíntese , Manipulação de Alimentos , Doenças Profissionais/microbiologia , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/metabolismo , Brasil/epidemiologia , Portador Sadio/epidemiologia , DNA Bacteriano/análise , Eletroforese em Gel de Campo Pulsado , Dedos/microbiologia , Humanos , Resistência a Meticilina/genética , Testes de Sensibilidade Microbiana , Unhas/microbiologia , Mucosa Nasal/microbiologia , Doenças Profissionais/epidemiologia , Infecções Estafilocócicas/epidemiologia , Staphylococcus aureus/genética , Staphylococcus aureus/isolamento & purificaçãoRESUMO
1. Strains of Yersinia enterocolitica, Y. intermedia, Y. frederiksenii and Y. kristensenii from non-human sources were examined for virulence factors. Four of these strains were positive for autoagglutination, three were calcium dependent at 37 degrees C, three produced lipase, five had the ability to bind Congo red, six had pyrazinamidase activity, and two had a 42 MDa plasmid. 2. One strain (Y. enterocolitica 0:5) was lethal for mice and had the ability to invade guinea pig eyes and HeLa cells. After inoculation of mice by the intravenous route, this strain was isolated from the cecum. The spleen, liver, kidneys and lymph nodes presented necrosis. After intragastric inoculation, the strain was isolated from all of the organs and tissues examined. 3. Three of the remaining strains invaded HeLa cells but none caused guinea pig conjunctivitis. 4. After intragastric inoculation, all the strains were isolated from the cecum but disappeared between days 3 and 6. After intravenous infection, three strains produced necrosis of the spleen and were more invasive, eliciting infection in various organs. The remaining strains caused hypertrophy and hyperplasia of Peyer's patches and/or lymph nodes. 5. These results indicate that Y. enterocolitica 0:5 can be considered as virulent as typical European Y. enterocolitica strains. The remaining strains perhaps induce a weak immune response independent of virulence factors.
Assuntos
Yersiniose/microbiologia , Yersinia/patogenicidade , Animais , Células HeLa/microbiologia , Humanos , Dose Letal Mediana , Camundongos , Sorotipagem , Virulência , Yersinia/classificação , Yersinia/isolamento & purificaçãoRESUMO
1. Strains of Yearsinia enterocolitica, Y. intermedia, Y frederiksenii and Y. kristensenii from non-human sources were examined for virulence factors. Four of these strains were positive for autoagglutination, three were calcium dependent at 37-C, three produced lipase, five had the ability to bind Congo red, six had pyrazinamidase activity, and two had a 42 MDa plasmid. 2. One strain (Y. enterocolitica 0:5) was lethal for mice and had the ability to invade guinea pig eyes and HeLa cells. After inoculation of mice by the intravenous route, this strain was isolated from the cecum. The spleen, liver, kidneys and lymph nodes presented necrosis. After intragastric inoculation, the strain was isolated from all of the organs and tissues examined. 3. Three of the remaining strains invaded HeLa cells but none caused guinea pig conjunctivitis. 4. After intragastric inoculation, all the strains were isolated from the cecum but disappeared between dys 3 and 6. After intravenous infection, three strains produced necrosis of the spleen and were more invasive, eliciting infection in various organs. The remaining strains caused hypertrophy and hyperplasua of Peyer's patches and/or lymph nodes. 5. These results indicate that Y. enterocolitica 0:5 can be considered as virulent as typical European Y. enterocolitica strains. The remaining strains perphaps induce a weak immune response independent of virulence factors
Assuntos
Animais , Camundongos , Yersiniose/microbiologia , Yersinia/patogenicidade , Células HeLa/microbiologia , Dose Letal Mediana , Sorotipagem , Virulência , Yersinia/genética , Yersinia/isolamento & purificaçãoRESUMO
Two Staphylococcus aureus strains were grown in brain-heart infusion (BHI) broth and a meat medium with Bacillus cereus, Streptococcus faecalis, Escherichia coli, and Pseudomonas aeruginosa. Both S. aureus strains grew well and produced enterotoxin in the presence of S. faecalis in BHI broth; however, enterotoxin production was observable in the meat medium only when the S. aureus inoculum was greater than the S. faecalis inoculum. S. aureus FRI-100 grown with B. cereus produced enterotoxin in both media only when the S. aureus inoculum was much higher than the B. cereus inoculum (10 versus 10(4) CFU), whereas S. aureus FRI-196E produced enterotoxin in both media at all inoculum combinations except in the meat medium, when the inocula of the two organisms were the same. S. aureus grown with E. coli in BHI broth produced enterotoxin at all inoculum combinations except when the E. coli inoculum was greater than the S. aureus inoculum; however, in the meat medium, enterotoxin was produced only when the S. aureus inoculum was much greater than the E. coli inoculum (10 versus 10(4) CFU), S. aureus FRI-100 grown with P. aeruginosa in either medium produced enterotoxin only when the S. aureus inoculum was much greater than the P. aeruginosa inoculum (10 versus 10(3) or 10(4) CFU). It can be concluded from these results that enterotoxin production is unlikely in mixed cultures unless the staphylococci outnumber the other contaminating organisms.
Assuntos
Enterotoxinas/biossíntese , Microbiologia de Alimentos , Staphylococcus aureus/metabolismo , Bacillus cereus/crescimento & desenvolvimento , Meios de Cultura , Enterococcus faecalis/crescimento & desenvolvimento , Escherichia coli/crescimento & desenvolvimento , Pseudomonas aeruginosa/crescimento & desenvolvimento , Staphylococcus aureus/crescimento & desenvolvimentoRESUMO
Sera from 33 persons with staphylococcal infections and from 37 healthy persons were surveyed for the presence of antibody to staphylococcal enterotoxins A, B, C, D, and E and toxic shock syndrome toxin 1. Thirty-one (93.9%) of the patients and 35 (94.6%) of the control group had antibodies to one or more of the enterotoxins. The numbers of patients with antibody to the enterotoxins were as follows: A, 8; B, 9; C, 7; D, 17; E, 21; and toxic shock syndrome toxin 1, 11. The numbers of healthy individuals with antibody to the enterotoxins were as follows: A, 6; B, 12; C, 8; D, 27; E, 21; and toxic shock syndrome toxin 1, 9.
Assuntos
Antitoxinas/análise , Toxinas Bacterianas , Enterotoxinas/imunologia , Infecções Estafilocócicas/imunologia , Staphylococcus aureus , Superantígenos , Brasil , HumanosRESUMO
O estudo de 137 estirpes de Staphylococcus aureus, recentemente isoladas de pacientes nao hospitalizados e de alimentos, mostrou alta percentagem de resistencia a penicilina G e percentual variavel a eritromicina, cloranfenicol, tetraciclina, canamicina, amicacina, sulfadiazina e estreptomicina. Uma estirpe produziu enterotoxina B e mal produziram enterotoxina C. Agentes estafilococcinogenicos foram detectados em 13 estirpes