AUTHOR=Yang Xiaojuan , Wu Qingping , Zhang Jumei , Huang Jiahui , Chen Ling , Wu Shi , Zeng Haiyan , Wang Juan , Chen Moutong , Wu Haoming , Gu Qihui , Wei Xianhu 

TITLE=Prevalence, Bacterial Load, and Antimicrobial Resistance of Salmonella Serovars Isolated From Retail Meat and Meat Products in China

JOURNAL=Frontiers in Microbiology

VOLUME=10

YEAR=2019

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2019.02121

DOI=10.3389/fmicb.2019.02121

ISSN=1664-302X

ABSTRACT=<p><italic>Salmonella</italic> remains the leading cause of reported bacterial foodborne disease in China. Meat products are recognized as one of the major sources of human salmonellosis; however, there is a lack of comprehensive, quantitative data concerning <italic>Salmonella</italic> contamination of these foods. Therefore, the objectives of this study were to investigate the prevalence, bacterial load, and antimicrobial resistance profiles of various <italic>Salmonella</italic> serovars in retail meat across the whole of China. Between July 2011 and June 2016, a total of 807 retail meat samples were collected, covering most provincial capitals in China. Overall, 159 (19.7%) samples tested positive for <italic>Salmonella</italic>. The highest contamination rate occurred in pork (37.3%, <italic>n</italic> = 287), followed by beef (16.1%, <italic>n</italic> = 161), mutton (10.9%, <italic>n</italic> = 92), dumplings (6.6%, <italic>n</italic> = 212), and smoked pork (3.6%, <italic>n</italic> = 55). Most probable number (MPN) analysis revealed that contamination was mainly in the range of 0.3–10 MPN/g among those samples testing positive using this method (<italic>n</italic> = 83), with eight samples exceeding 110 MPN/g. Among the 456 <italic>Salmonella enterica</italic> subsp. <italic>enterica</italic> isolates obtained in this study, 29 serovars and 33 multilocus sequence typing patterns were identified, with <italic>S.</italic> Derby, <italic>S.</italic> Typhimurium, <italic>S.</italic> London, <italic>S.</italic> Rissen, <italic>S.</italic> 1,4,[5],12:i:-, <italic>S.</italic> Weltevreden, and <italic>S.</italic> Enteritidis being the most prevalent. Among the 218 non-duplicate isolates, 181 (83.0%) were resistant to at least one class of antimicrobials and 128 (58.7%) were resistant to at least three classes. High rates of resistance were observed for tetracycline (65.6%), ampicillin (45.4%), trimethoprim-sulfamethoxazole (40.8%), streptomycin (40.4%), and nalidixic acid (35.8%), with the seven most prevalent serovars, except <italic>S.</italic> Weltevreden, showing higher rates of resistance and multidrug resistance compared with the less dominant serovars. Of note, all <italic>S.</italic> Indiana isolates exhibited resistance to extended-spectrum cephalosporins (including ceftriaxone and cefepime), ciprofloxacin, and multiple other classes of antibiotics. Further, two <italic>S</italic>. <underline>1</underline>,4,[5],12:i:- isolates showed resistance to imipenem. This study provides systematic and comprehensive data on the prevalence and antimicrobial resistance profiles of various <italic>Salmonella</italic> serovars isolated from meat products in China, indicating their potential risk to public health.</p>