Staphylococcus aureus, a major food-poisoning pathogen, is a common contaminant in dairy industries worldwide, including in Brazil. We determined the occurrence of S. aureus in five dairies in Brazil over 8 months. Of 421 samples, 31 (7.4%) were positive for S. aureus and prevalence varied from 0 to 63.3% between dairies. Sixty-six isolates from the 31 samples were typed by Multi-Locus Sequence...

The structural genes which constitute the cholera toxin operon, ctxAB, were genetically mapped in the Vibrio cholerae El Tor strain RV79. This strain of V. cholerae contains two copies of the ctx operon located on a 7-kilobase-pair tandemly duplicated region. We began by isolating a vibriophage VcA1 insertion mutation in one of the two ctxA genes located in this region. The mutant carrying this...

Strains of Yersinia enterocolitica produce a heat-stable enterotoxin which is positive in the suckling mouse bioassay. Partial purification by a procedure previously worked out for heat-stable Escherichia coli enterotoxin yielded a substance which increases particulate guanylate cyclase activity and short-circuit current and inhibits active Cl-absorption in rabbit ileal mucosa. These effects of...

Recently, we demonstrated rapid dissemination of different methicillin-resistant Staphylococcus aureus (MRSA) clones at the Institute for Microbiology at the University of Magdeburg (B. Ghebremedhin, W. König, and B. König, Eur. J. Clin. Microbiol. Infect. Dis. 24:388-398, 2005). The majority of them harbored the readily transmissible mec cassette type IV. Thus, theoretically, methicillin-susce...

Staphylococcus pseudintermedius is a genuine opportunistic pathogen of the skin, especially in canids. However, characterisation of virulence, antimicrobial resistance and genotypic variability in methicillin-susceptible S. pseudintermedius isolates has not been fully explored. In this study, coagulase-positive staphylococcal isolates collected from dogs of various breeds and ages suffering fro...

The objectives of this study were to evaluate the prevalence of Bacillus cereus spores in vegetables and to investigate the toxigenic characteristics of spore isolates. The detection rate of spores was 26.7% (12 out of 45 samples) which possess a higher risk of food poisoning than vegetative cell. The occurrence rate of toxin genes in spore isolates were 91.7, 100 and 100% for hblCDA, nheABC an...

Three variants of the chloramine-T radioiodination method were used to iodinate staphylococcal enterotoxin A with 125I. Only one method consistently produced usable labels for radioimmunoassay. The iodine incorporation was 55 to 76%; the specific activity was 3.5 to 5.5 muCi/microgram of enterotoxin, and the label was extremely stable on storage at -20 degrees C. Determinations of the enterotox...