AUTHOR=Thung Tze Y. , Radu Son , Mahyudin Nor A. , Rukayadi Yaya , Zakaria Zunita , Mazlan Nurzafirah , Tan Boon H. , Lee Epeng , Yeoh Soo L. , Chin Yih Z. , Tan Chia W. , Kuan Chee H. , Basri Dayang F. , Wan Mohamed Radzi Che W. J. 

TITLE=Prevalence, Virulence Genes and Antimicrobial Resistance Profiles of Salmonella Serovars from Retail Beef in Selangor, Malaysia

JOURNAL=Frontiers in Microbiology

VOLUME=8

YEAR=2018

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2017.02697

DOI=10.3389/fmicb.2017.02697

ISSN=1664-302X

ABSTRACT=<p>The aim of the present study was to investigate the prevalence of <italic>Salmonella</italic> spp., <italic>Salmonella</italic> Enteritidis and <italic>Salmonella</italic> Typhimurium in retail beef from different retail markets of Selangor area, as well as, to assess their pathogenic potential and antimicrobial resistance. A total of 240 retail beef meat samples (chuck = 60; rib = 60; round = 60; sirloin = 60) were randomly collected. The multiplex polymerase chain reaction (mPCR) in combination with the most probable number (MPN) method was employed to detect <italic>Salmonella</italic> spp., <italic>S</italic>. Enteritidis and <italic>S</italic>. Typhimurium in the meat samples. The prevalence of <italic>Salmonella</italic> spp., <italic>S</italic>. Enteritidis and <italic>S</italic>. Typhimurium in 240 beef meat samples were 7.50, 1.25, and 0.83%, respectively. The microbial loads of total <italic>Salmonella</italic> was found in the range of &lt;3 to 15 MPN/g. Eight different serovars of <italic>Salmonella</italic> were identified among the 23 isolates, and <italic>S</italic>. Agona was the predominant serovar (26.09%). Interestingly, all the <italic>Salmonella</italic> isolates were resistant to penicillin, erythromycin and vancomycin, but the sensitivity was observed for tetracycline, gentamicin and amoxicillin/clavulanic acid. All 23 isolates were resistant to at least three antibiotics. Two <italic>S</italic>. Typhimurium isolates (8.70%) exhibited the highest multiple antibiotic resistance (MAR) index value of 0.56 which shown resistance to nine antibiotics. PCR analysis of virulence genes showed that all <italic>Salmonella</italic> isolates (100%) were positive for the <italic>invA</italic> gene. Meanwhile, <italic>pefA</italic> was only identified in <italic>S</italic>. Enteritidis and <italic>S</italic>. Typhimurium. The findings in this study indicate that retail beef products tested were widely contaminated with multi-drug resistant (MDR) <italic>Salmonella</italic> and various virulence genes are present among the isolated <italic>Salmonella</italic> serovars.</p>