title: Molecular Typing and Virulence Gene Profiles of Enterotoxin Gene Cluster (egc)-Positive Staphylococcus aureus Isolates Obtained from Various Food and Clinical Specimens.
abstract: The enterotoxin gene cluster (egc) has been proposed to contribute to the Staphylococcus aureus colonization, which highlights the need to evaluate genetic diversity and virulence gene profiles of the egc-positive population. Here, a total of 43 egc-positive isolates (16.2%) were identified from 266 S. aureus isolates that were obtained from various food and clinical specimens in Shanghai. Seven different egc profiles were found based on the polymerase chain reaction (PCR) result for egc genes. Then, these 43 egc-positive isolates were further typed by multilocus sequence typing, pulsed-field gel electrophoresis (PFGE), multiple-locus variable-number tandem-repeat analysis (MLVA), and accessory gene regulatory (agr) typing. It showed that the 43 egc-positive isolates displayed 17 sequence types, 28 PFGE patterns, 29 MLVA types, and 4 agr types, respectively. Among them, the dominant clonal lineage was CC5-agr II (48.84%). Thirty toxin and 20 adhesion-associated genes were detected by PCR in egc-positive isolates. Notably, invasive toxin genes showed a high prevalence, such as 76.7% for Panton-Valentine leukocidin encoding genes, 27.9% for sec, and 23.3% for tsst-1. Most of the examined adhesion-associated genes were found to be conserved (76.7-100%), whereas the fnbB gene was only found in 8 (18.6%) isolates. In addition, 33 toxin gene profiles and 13 adhesion gene profiles were identified, respectively. Our results imply that isolates belonging to the same clonal lineage harbored similar adhesion gene profiles but diverse toxin gene profiles. Overall, the high prevalence of invasive virulence genes increases the potential risk of egc-positive isolates in S. aureus infection.
authors: 1 MOST-USDA Joint Research Center for Food Safety, School of Agriculture and Biology, and State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University , Shanghai, P.R. China .
authors: Minghui
authors: M
authors: Song
authors: 1 MOST-USDA Joint Research Center for Food Safety, School of Agriculture and Biology, and State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University , Shanghai, P.R. China .
authors: Chunlei
authors: C
authors: Shi
authors: 2 Shanghai Municipal Center for Disease Control and Prevention , Shanghai, P.R. China .
authors: Xuebing
authors: X
authors: Xu
authors: 1 MOST-USDA Joint Research Center for Food Safety, School of Agriculture and Biology, and State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University , Shanghai, P.R. China .
authors: Xianming
authors: X
authors: Shi
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001427:Bacterial Toxins / Q000235:genetics / Q000378:metabolism; D015815:Cell Adhesion Molecules / Q000235:genetics / Q000378:metabolism; D002681:China; D016521:Electrophoresis, Gel, Pulsed-Field; D004768:Enterotoxins / Q000235:genetics / Q000378:metabolism*; D005098:Exotoxins / Q000235:genetics / Q000378:metabolism; D005516:Food Microbiology; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D006801:Humans; D007956:Leukocidins / Q000235:genetics / Q000378:metabolism; D058889:Molecular Typing / Q000379:methods; D005810:Multigene Family; D058885:Multilocus Sequence Typing; D010802:Phylogeny; D011110:Polymorphism, Genetic; D013202:Staphylococcal Food Poisoning / Q000382:microbiology* / Q000503:physiopathology; D013211:Staphylococcus aureus / Q000145:classification / Q000302:isolation & purification / Q000378:metabolism* / Q000472:pathogenicity; D020080:Tandem Repeat Sequences; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism*; D014839:Vomiting / Q000209:etiology
chemical_list: C095698:Agr protein, Staphylococcus aureus; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D015815:Cell Adhesion Molecules; D004768:Enterotoxins; D005098:Exotoxins; D007956:Leukocidins; C078284:Panton-Valentine leukocidin; D015534:Trans-Activators; D037521:Virulence Factors
keywords: MLST; MLVA; Staphylococcus aureus; adhesion genes; enterotoxin gene cluster (egc); toxin genes