基于方法学评估与检测基线预测广西玉林市从业人员沙门菌带菌水平

Methodological assessment and detection base line based prediction of Salmonella carriage level in catering and public service employees in Yulin

目的基于沙门菌筛检流程的方法评价和检测基线,预测广西壮族自治区(广西)玉林市从业人员沙门菌的带菌水平。方法以沙门菌选择性增菌液(SBG)和3种选择性平板(CAS、XLD、DHL)构建沙门菌筛选和检定流程,通过测试菌株和408份从业者粪便样品实测获得统计参数,据此评估不同组合流程(SBG-CAS/XLD/DHL)筛检沙门菌的敏感性、特异性和阳性预测值;基于SBG-DHL分离沙门菌的敏感性校准和预测2014-2017年玉林市从业人员的带菌水平。结果CAS、XLD、DHL对测试菌株的敏感性和特异性分别为100.00%和96.67%、100.00%和83.33%、83.33%和50.00%;应用组合流程筛检408份从业人员粪便,共分离沙门菌22株,带菌率为5.39%;敏感性和阳性预测值分别为95.45%和89.23%(CAS)、86.36%和27.72%(XLD)、68.18%和16.15%(DHL)、100.00%和29.27%(CAS+XLD);CAS+XLD组合发现1例兼有硫化氢阴性和阳性的罗森沙门菌的无症状带菌者;校准和预测2014-2017年玉林市从业人员的平均年度带菌率为3.35%,以实测人数评估地区从业人员的带菌水平约为3350/10万。结论沙门菌检测敏感性和阳性预测值可作为检测质量和方法学的评价指标,大数据证实华南地区从业人员中沙门菌的高比例持留,公共卫生机构应加强沙门菌带菌者的防控,降低食源性病原菌的隐性扩散风险。

Objective To predict the carriage level of Salmonella in catering and public service employees in Yulin in Guangxi based on the base line and methodological assessment of Salmonella detection process.Method The selective enrichment broth(SBG)and selective plates(CAS,XLD,DHL)were used to establish Salmonella screening techniques process.Statistical parameters were obtained through the detections of stock strains and 408 stool samples of the employees for the evaluation of the sensitivity,specificity and positive predictive value of different combination process(SBG+CAS/XLD/DHL)in the detection of Salmonella.The Salmonella carriage level in catering and public service employees in Yulin from 2014 to 2017 were adjusted and predicted according to the sensitivity of SBG-DHL in Salmonella isolation.Results Reference stock strain detection showed that the sensitivity and specificity of CAS,XLD and DHL were 100.00%and 96.67%,100.00%and 83.33%,83.33%and 50.00%,respectively.A total of 22 Salmonella strains were isolated from 408 stool samples by using combined plates,the positive rate was 5.39%.The sensitivity and positive predictive rates were 95.45%and 89.23%for CAS,86.36%and 27.72%for XLD,68.18%and 16.15%for DHL,100.00%and 29.27%for CAS+XLD,respectively.A Salmonella Rissen isolate with both hydrogen sulfide-negative and positive clones was isolated from an asymptomatic carrier by CAS and XLD.Through the calibration and prediction,the annual rate of Salmonella carriage was 3.35%in the employees from 2014 to 2017.Accordingly,we predicted that the Salmonella carriage rate was 3350/100000 in catering and public service employees in Yulin of Guangxi.Conclusion The sensitivity and positive predictive rate of Salmonella detection can be used as the indicators for evaluation of detection quality and methodologies.Big data confirmed that the high Salmonella carriage arte was persistent in catering and public service employees in southern China.It is necessary to strengthen the screening of asymptomatic Salmonella carriers to reduce the recessive spread of food-borne pathogenic bacteria.