Molecular characteristics of Staphylococcus aureus isolates from food surveillance in southwest China

Abstract

BackgroundStaphylococcal food poisoning (SFP) is one of the most common food-borne diseases in the world. Pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST) and spa typing methods were used to characterize Staphylococcus aureus isolates from food surveillance during 2013–2015 in southwest China, and Staphylococcal cassette chromosome mec (SCCmec) typing was used for methicillin-resistant S. aureus (MRSA). Isolates were also examined for their antibiotic resistance and carriage of virulence genes.ResultsIsolation rate of S. aureus was 2.60% during the three years’ surveillance and 29.50% of them were MRSA. All the S. aureus had hla genes (100%), 14.34% of the strains had tst, and 16.73% had PVL. 163 PFGE-SmaI patterns, 41 ST types and 36 spa types were obtained for all the S. aureus. Among them, ST6-t701 (13.15%), ST7-t091 (12.75%), ST59-t437 (9.96%) and ST5-t002 (7.57%) were the prevalent genotypes. Most of MRSA in this study belonged to SCCmec IV and V, accounted for 74.32% and 20.27% respectively. ST6-SCCmec IV-t701 (36.50%) was the most prevalent clone among isolates from food, followed by ST59-SCCmec V-t437 (20.30%), ST5-SCCmec IV-t002 (12.20%) and ST59-SCCmec IV-t437 (12.20%). Some strains had the identical PFGE patterns, ST and spa types with isolates from patients.ConclusionsS. aureus isolated from food in southwest China displayed heterogeneity. Isolates had the same genotype profiles with isolates from patients, indicating high homology.Electronic supplementary materialThe online version of this article (10.1186/s12866-018-1239-z) contains supplementary material, which is available to authorized users.

Molecular epidemiology, genetic diversity and antimicrobial resistance of Staphylococcus aureus isolated from chicken and pig carcasses, and carcass handlers

“…This could facilitate the contamination of chicken carcasses and the handlers unlike the pig carcasses that were washed using different containers of water because of their size. Lower isolation rates of 0.72% and 0.86% have been reported in food samples including meat from Nujiang and Yuxi provinces, respectively, in China [37]. The high level of contamination observed in this study could also be attributed to the poor state (lack of regular source of water for hygienic dressing of carcasses and cleaning the environment, no proper disposal of waste arising from the dressing carcasses, lack of In this study, 41 (77.4%) of the 53 S. aureus isolates studied were MSSA while 12 (22.6%) were MRSA.…”

A comparative genomic analysis between methicillin-resistant Staphylococcus aureus strains of hospital acquired and community infections in Yunnan province of China

“…In our study, Yunnan isolates from southwest China were closely related to T0131 and clustered with strains of the 'Turkish clade' from Eastern Europe. We considered the similar ST239-t030 clonal Yunnan isolates in this study were more likely to demonstrate the local endemic of primary clone Our previous study [14] compared the S. aureus isolates from patients and food, the results showed some strains from patients had identical PFGE patterns, ST and spa types with food isolates. These strains were dominated with ST6-t701, ST5-t14723, ST59-t437 and ST965-t062, specifically for ST6-t701.…”

“…However, ST59 clone of isolates were the primary CA-MRSA infections in Asia [12,13]. Furthermore, our previous study [14] on molecular characteristics of S. aureus from food surveillance indicated that ST6-t701 was the prevalent genotypes in southwest China, and some strains had the same genotype profiles with patients' isolates. The different clonal structures of MRSA strains maybe represent the different infection sources or disease spectrums.…”

Large-Scale Staphylococcus aureus Foodborne Disease Poisoning Outbreak among Primary School Children

“…ST6 is a clone commonly associated with foodborne S. aureus infections, e.g., in China [23][24][25][26], whereas other clones predominated in such outbreaks in South Korea (ST1, ST59, and ST30 [19]), Japan (ST45 and ST81 [20][21][22]) and Europe (ST45 and ST5 [23,24]). In China, both ST6-t701 [25] and ST6-t304 [23] have been described as being highly prevalent. The resistance profiles of the ST6 isolates in China are highly diverse, ranging from being fully susceptible to resistant to several antimicrobials with our outbreak ST6-t701 clone, showing penicillin and tetracycline resistance only.…”