Phenotypic characterization and prevalence of enterotoxin genes in Staphylococcus aureus isolates from outbreaks of illness in Chengdu City
Autor: | Yiwu Du, Huanrong Zhang, Junni Tang, Xiao-nong Yang, Changting Wang, Hua Yue, Cheng Tang, Juan Chen |
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Rok vydání: | 2011 |
Předmět: |
DNA
Bacterial China Staphylococcus aureus Enterotoxin Biology medicine.disease_cause Applied Microbiology and Biotechnology Microbiology Polymerase Chain Reaction law.invention Disease Outbreaks Enterotoxins law Genotype medicine Prevalence Food microbiology Humans Polymerase chain reaction DNA Primers Food poisoning medicine.disease 16S ribosomal RNA Staphylococcal Food Poisoning Phenotype Food Microbiology Animal Science and Zoology Food Science |
Zdroj: | Foodborne pathogens and disease. 8(12) |
ISSN: | 1556-7125 |
Popis: | Staphylococcus aureus produces a spectrum of enterotoxin that is recognized as the main reason for causing staphylococcal food poisoning. The aim of the current study was to investigate the phenotypic characteristics and enterotoxin genotypes of S. aureus isolated from food poisoning sufferers. On the basis of the amplification of 16S rRNA and nuc gene specific to S. aureus assay and the phenotype (hemolytic activity, thermal stable nuclease [Tnase] test, and biofilm formation), all isolates were identified as S. aureus. To genotypically characterize S. aureus isolates, genes encoding staphylococcal enterotoxin (sea, seb, sec, sed, see, seg, seh, sei, sej, sek, sem, sen, ser, and seu) were investigated by using polymerase chain reaction technique. The results showed that the eight isolates of S. aureus had different enterotoxin genotypic characteristics, which was the main cause of food poisoning. One isolate contained 10 enterotoxin genes, and the other 7 isolates carried 3 or more enterotoxin genes. The frequency of the newly identified enterotoxin genes (seg-seu) was higher than classical genes (sea-see). Overall, multi-gene detection rates were 75% (for sek, ser, and seu); 50% (for sea and sem); 37.5% (for sen, seg, and sei); and 12.5% (for seb, sec, sed, and sej), respectively. The see and seh gene were not detected in any isolates. The current study provided the exact distribution of enterotoxin genes in eight S. aureus strains from food poisoning sufferers, which indicated that the pathogenicity of the newly identified enterotoxin should be highlighted. The need for prevention of food poisoning occurrences caused by enterotoxin of S. aureus should be reinforced. |
Databáze: | OpenAIRE |
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