摘要
目的研究验证大样本量(2 kg)生食果蔬中沙门氏菌的富集检测方法,分析北京市售生食果蔬中沙门氏菌的污染、血清型及耐药性等多重特征。方法比较25g样品直接增菌检测和2kg样品清洗、富集检测2种方式对圣女果和生菜中沙门氏菌检测的灵敏度。采集北京市售圣女果和生菜,使用上述方法进行沙门氏菌分离、鉴定,通过微量肉汤稀释法测定分离菌株对9类16种抗生素敏感性,并通过全基因组测序分析分离菌株的血清型、多位点序列分型以及耐药基因。结果大样本量(2kg)结合样品清洗、富集检测法可提升生食果蔬中沙门氏菌的检测灵敏度,检出限可达到10^(0)CFU/样品。在北京地区的应用验证显示,2kg检样量对沙门氏菌检出率(8.9%)较25 g检样量(0.8%)有显著提升(P<0.01)。12株生食果蔬分离的沙门氏菌分为9种血清型。耐药分析显示,66.7%的菌株对至少1种抗生素出现耐药,41.7%的菌株存在多重耐药。从分离株中共检出9类28种抗生素耐药基因和5种喹诺酮耐药决定区点突变。结论大样本量(2 kg)结合清洗、富集检测法可显著提高生食果蔬中沙门氏菌的检出率,可为生食果蔬中沙门氏菌的监测与风险防控提供可靠方法和有效的数据支撑。
Objective To validate an enrichment-based detection method for Salmonella in large-sample(2 kg)raw fruits and vegetables,and to analyze multiple characteristics of contamination,serotypes and antimicrobial resistance of Salmonella isolates from retail raw fruits and vegetables in Beijing.Methods The sensitivity of Salmonella detection in Solanum lycopersicum L.and Lactuca sativa L.was compared between 2 kinds of approaches:Direct enrichment detection of 25 g sample and washing combined with enrichment detection of 2 kg sample.Retail Solanum lycopersicum L.and Lactuca sativa L.were collected in Beijing,and Salmonella strains were isolated and identified using the above methods.The antimicrobial susceptibility of the isolates to 16 kinds of antibiotics across 9 antibiotics classes was determined by the broth microdilution method.Whole genome sequencing was performed to analyze serotypes,multilocus sequence types and antimicrobial resistance genes.Results The large-sample(2 kg)protocol incorporating washing and enrichment significantly improved the detection sensitivity of Salmonella in raw fruits and vegetables,achieving a limit of detection of 10^(0) CFU per sample.Validation in Beijing showed that,the detection rate of Salmonella in the 2 kg sample method(8.9%)was significantly higher than that in the 25 g sample method(0.8%)(P<0.01).The 12 Salmonella isolates were classified into 9 kinds of serotypes.Antimicrobial resistance analysis revealed that 66.7% of the isolates were resistant to at least one antibiotic,and 41.7% exhibited multidrug resistance.A total of 28 kinds of antibiotic resistance genes across 9 antibiotic classes and 5 kinds of quinolone resistance-determining region mutations were identified in the isolates.Conclusion The large-sample(2 kg)protocol combined with washing and enrichment significantly improves the detection rate of Salmonella,and provides a reliable method and valuable data for surveillance and risk management of Salmonella in raw fruits and vegetables.
作者
王学硕
窦越
瞿洪仁
任秀
赵帅
李景云
崔生辉
WANG Xue-Shuo;DOU Yue;QU Hong-Ren;REN Xiu;ZHAO Shuai;LI Jing-Yun;CUI Sheng-Hui(National Institutes for Food and Drug Control,Beijing 100050,China)
出处
《食品安全质量检测学报》
2025年第22期11-17,共7页
Journal of Food Safety and Quality
基金
国家重点研发计划项目(2022YFC2303900)。
关键词
生食果蔬
沙门氏菌
富集检测
全基因组测序
raw fruits and vegetables
Salmonella
enrichment-based detection
whole genome sequencing
