Prevalence and Characterization of Monophasic Salmonella Serovar 1,4,[5],12:i:- of Food Origin in China

• Published in: PloS one Vol. 10; no. 9; p. e0137967
• Main Authors: Yang, Xiaojuan, Wu, Qingping, Zhang, Jumei, Huang, Jiahui, Guo, Weipeng, Cai, Shuzhen
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 11.09.2015; Public Library of Science (PLoS)
• Subjects: Ampicillin; Anti-Bacterial Agents - pharmacology; Antibiotic resistance; Antibiotics; Antigens; Antimicrobial agents; Causes of; China - epidemiology; Clonal deletion; Drug resistance; Drug Resistance, Bacterial; Epidemiology; Food chains; Food contamination; Food contamination & poisoning; Food Microbiology - statistics & numerical data; Food production; Food safety; Food sources; Gene Deletion; Genes; Genes, Bacterial; Genetic aspects; Genotypes; Health risks; Hogs; Humans; Identification and classification; Laboratories; Microbial Sensitivity Tests; Multidrug resistant organisms; Multilocus Sequence Typing; Polymerase Chain Reaction; Pork; Prevalence; Public health; Public health administration; Risk management; Salmonella; Salmonella enterica; Salmonella enterica - classification; Salmonella enterica - drug effects; Salmonella enterica - genetics; Salmonella enterica - isolation & purification; Salmonella Food Poisoning; Salmonella Infections - epidemiology; Salmonella Infections - microbiology; Salmonella typhimurium - classification; Salmonella typhimurium - genetics; Salmonella typhimurium - isolation & purification; Salmonellosis; Serogroup; Serotyping; Streptomycin; Sulfonamides; Virulence - genetics; Zoonoses; China
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0137967

Salmonella enterica subsp. enterica serovar 1,4,[5],12:i:- is a monophasic variant of Salmonella Typhimurium, which has recently been recognized as an emerging cause of infection worldwide. This bacterium has also ranked among the four most frequent serovars causing human salmonellosis in China. However, there are no reports on its contamination in Chinese food. Serotyping, polymerase chain reaction, antibiotic resistance, virulotyping, and multilocus sequence typing (MLST) assays were used to investigate the prevalence of this serological variant in food products in China, and to determine phenotypic and genotypic difference of monophasic isolates and Salmonella Typhimurium isolated over the same period. Salmonella 1,4,[5],12:i:- was prevalent in various food sources, including beef, pork, chicken, and pigeon. The study also confirmed the high prevalence (53.8%) of resistance to ampicillin, streptomycin, sulfonamides, and tetracycline in Salmonella 1,4,[5],12:i:-, which was higher than that in Salmonella Typhimurium. Moreover, Salmonella 1,4,[5],12:i:- isolates in our study were different from Salmonella Typhimurium isolates by the absence of three plasmid-borne genes (spvC, pefA, and rck) and the presence of gipA in all isolates. All Salmonella 1,4,[5],12:i:- isolates demonstrated MLST pattern ST34. Genomic deletions within the fljBA operon and surrounding genes were only found in Salmonella 1,4,[5],12:i:- isolates, with all isolates containing a deletion of fljB. However, hin and iroB were identified in all Salmonella 1,4,[5],12:i:- isolates. Three different deletion profiles were observed and two of them were different from the reported Salmonella 1,4,[5],12:i:- clones from Spain, America, and Italy, which provided some new evidence on the independent evolution of the multiple successful monophasic clones from Salmonella Typhimurium ancestors. This study is the first report of Salmonella 1,4,[5],12:i:- in food products from China. The data are more comprehensive and representative, providing valuable information for epidemiological studies, risk management, and public health strategies.