title: Prevalence, toxin gene profiles, and antimicrobial resistance of Staphylococcus aureus isolated from quick-frozen dumplings.
abstract: The aim of this study was to investigate the prevalence of Staphylococcus aureus in quick-frozen dumplings and to characterize these strains. A total of 120 dumpling samples, including lamb (n = 13), vegetarian (n = 14), seafood (n = 12), and pork (n = 81) stuffing, were collected in Shaanxi province in China and screened for S. aureus. All S. aureus isolates were characterized by antimicrobial susceptibility testing, and detection of genes encoding staphylococcal enterotoxins, exfoliative toxins A and B (eta and etb), toxic shock syndrome toxin 1 (tsst-1), and resistance to methicillin-oxacillin (mecA). In all, 60.0% of all samples were positive for S. aureus, and 117 S. aureus isolates, including seven mecA-positive strains, were recovered from these positive samples. In addition, all mecA-positive S. aureus isolates were recovered from products of animal origin. In these S. aureus isolates, resistance was observed most frequently to ampicillin (92.3%) and penicillin (86.3%), followed by clarithromycin, erythromycin, midecamycin, tetracycline, and kanahemycin (from 53.8 to 28.2%). All isolates were sensitive to cefoperazone, minocycline, vancomycin, and ofloxacin. The predominant toxin gene was sec (38.5%), followed by seg (19.7%), sej (16.2%), see (12.8%), sea (11.1%), and seb (10.3%), whereas eta, etb, and tsst-1 genes were not detected. These findings indicate that S. aureus was present commonly in quick-frozen dumplings, accompanied by multiple antimicrobial resistance and toxin genes. Our findings highlight the urgency for stricter hygiene strategies in food production and the prudent use of antibiotics in the breeding industry.
authors.affiliation: College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi 712100, People's Republic of China, College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi 712100, People's Republic of China.
authors.forename: Dan
authors.initials: D
authors.lastname: Hao
authors.affiliation: College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi 712100, People's Republic of China.
authors.forename: Xiaonan
authors.initials: X
authors.lastname: Xing
authors.affiliation: College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi 712100, People's Republic of China.
authors.forename: Guanghui
authors.initials: G
authors.lastname: Li
authors.affiliation: College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi 712100, People's Republic of China. xinwang7516@nwsuaf.edu.cn.
authors.forename: Xin
authors.initials: X
authors.lastname: Wang
authors.affiliation: College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi 712100, People's Republic of China.
authors.forename: Min
authors.initials: M
authors.lastname: Zhang
authors.affiliation: College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi 712100, People's Republic of China.
authors.forename: Weisong
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Department of Nutrition and Food Science, University of Maryland, College Park, Maryland 20742, USA.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Xia
authors.affiliation: Department of Nutrition and Food Science, University of Maryland, College Park, Maryland 20742, USA.
authors.forename: Jianghong
authors.initials: J
authors.lastname: Meng
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001427:Bacterial Toxins / Q000235:genetics*; D002681:China; D024881:Drug Resistance, Bacterial; D005516:Food Microbiology; D005628:Frozen Foods / Q000382:microbiology*; D008460:Meat / Q000382:microbiology; D017747:Seafood / Q000382:microbiology; D012756:Sheep; D013211:Staphylococcus aureus / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification*; D013552:Swine; D059467:Transcriptome; D014675:Vegetables / Q000382:microbiology
chemical_list: D000900:Anti-Bacterial Agents; D001427:Bacterial Toxins