Prevalence and characterization of Salmonella isolated from raw vegetables in China. (March 2020)

• Record Type: Journal Article
• Authors: Yang, Xiaojuan; Wu, Qingping; Huang, Jiahui; Wu, Shi; Zhang, Jumei; Chen, Ling; Wei, Xianhu; Ye, Yingwang; Li, Yu; Wang, Juan; Lei, Tao; Xue, Liang; Pang, Rui; Zhang, Youxiong
• Is Part Of: Food control. Volume 109(2020)
• Publication Date: 2020-03
• Subjects: Salmonella -- Raw vegetables -- Serovars -- Prevalence -- Antibiotic resistance; Food -- Quality -- Periodicals; Food -- Analysis -- Periodicals; Food handling -- Periodicals; Food industry and trade -- Quality control -- Periodicals; Aliments -- Industrie et commerce -- Qualité -- Contrôle -- Périodiques; Aliments -- Qualité -- Périodiques; Aliments -- Analyse -- Périodiques; Hygiène alimentaire -- Périodiques; Food -- Analysis; Food handling; Food -- Quality; Periodicals; Electronic journals; 664.07
• DOI: 10.1016/j.foodcont.2019.106915
• Languages: English
• ISSNs: 0956-7135

Abstract

Abstract: Raw vegetables have been associated with numerous foodborne Salmonella outbreaks; however, there is little epidemiological or molecular data on Salmonella contaminants of raw vegetables in China. Here, we investigated the prevalence and molecular characteristics of Salmonella isolates from raw vegetables in China. In total, 406 raw vegetable samples were collected covering most provincial capitals in China. The overall prevalence of Salmonella was 3.4% (14/406), with contamination levels of <1 MPN/g. Coriander (7.8%, n = 90) and lettuce (6.0%, n = 83) showed the highest contamination rates. Among the 31 Salmonella isolates recovered from the 14 positive samples, 14 different serovars and 15 multilocus sequence typing patterns were identified. All of the identified serovars have previously caused infections in humans, with several also linked to raw vegetable-associated disease outbreaks. Of the 15 non-duplicate isolates, 7 (46.7%) were resistant to at least one class of antibiotics and 4 (26.7%) were multidrug-resistant. The highest rate of resistance was observed for nalidixic acid (33.3%). This study provides a systematical surveillance on prevalence of Salmonella in Chinese raw vegetables, and suggests that the Salmonella contamination of fresh vegetables is a potential risk to public health when they are eaten raw. Highlights: A high prevalence of Salmonella contamination was observed in raw vegetables. All Salmonella serovars identified in this study can cause human disease. Most of the serovars are linked to raw vegetable-associated disease outbreaks. Isolates from raw vegetables showed high rates of antimicrobial resistance.