AUTHOR=Zhang Yang , Xu Dongyang , Shi Lei , Cai Rujian , Li Chunling , Yan He 

TITLE=Association Between agr Type, Virulence Factors, Biofilm Formation and Antibiotic Resistance of Staphylococcus aureus Isolates From Pork Production

JOURNAL=Frontiers in Microbiology

VOLUME=9

YEAR=2018

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2018.01876

DOI=10.3389/fmicb.2018.01876

ISSN=1664-302X

ABSTRACT=<p>Livestock-associated <italic>Staphylococcus aureus</italic> colonization and/or infections exist in pigs and people in frequent contact with pigs. In this study, a total of 130 <italic>S. aureus</italic> isolates obtained from different stages of pork production were subjected to antimicrobial susceptibility, biofilm formation, as well as PCR screening to identify virulence genes, and the accessory gene regulator alleles (<italic>agr</italic>). Among all 130 <italic>S. aureus</italic> isolates, 109 (83.8%, 109/130) isolates were positive for <italic>agr</italic>. All swine farms isolates belonged to <italic>agr</italic> IV, whereas <italic>S. aureus</italic> isolated from slaughterhouse and retail indicated diverse <italic>agr</italic> types. All isolates exhibited biofilm formation ability, and raw meat isolates (belonging to <italic>agr</italic> I) exhibited a greater ability to form strong biofilms than swine farms isolates (belonging to <italic>agr</italic> IV). <italic>agr</italic>-positive isolates were associated with more virulence genes than <italic>agr</italic>-negative isolates. Most biofilm-producing isolates were positive for microbial surface component recognizing adhesive matrix molecule (MSCRAMM), capsule type and <italic>ica</italic> group genes. The results illustrate a significant association between the prevalence rate of MSCRAMM, capsule type and <italic>ica</italic> group genes among isolates producing weak, moderate and strong biofilms. The high prevalence of resistance to ciprofloxacin, gentamicin, tetracycline, clarithromycin, clindamycin, and trimethoprim-sulfamethoxazole were mainly observed in moderate and weak biofilm producers. Our findings indicate that <italic>S. aureus</italic> isolates from pork production displayed diverse molecular ecology.</p>