Callicott Kenneth A, Harğardóttir Hjördís, Georgsson Franklín, Reiersen Jarle, Friğriksdóttir Vala, Gunnarsson Eggert, Michel Pascal, Bisaillon Jean-Robert, Kristinsson Karl G, Briem Haraldur, Hiett Kelli L, Needleman David S, Stern Norman J
Poultry Microbiological Safety Research Unit, USDA-ARS, Athens, GA 30605, USA.
Appl Environ Microbiol. 2008 Nov;74(21):6483-94. doi: 10.1128/AEM.01129-08. Epub 2008 Sep 12.
To examine whether there is a relationship between the degree of Campylobacter contamination observed in product lots of retail Icelandic broiler chicken carcasses and the incidence of human disease, 1,617 isolates from 327 individual product lots were genetically matched (using the flaA short variable region [SVR[) to 289 isolates from cases of human campylobacteriosis whose onset was within approximately 2 weeks from the date of processing. When there was genetic identity between broiler isolates and human isolates within the appropriate time frame, a retail product lot was classified as implicated in human disease. According to the results of this analysis, there were multiple clusters of human disease linked to the same process lot or lots. Implicated and nonimplicated retail product lots were compared for four lot descriptors: lot size, prevalence, mean contamination, and maximum contamination (as characterized by direct rinse plating). For retail product distributed fresh, Mann-Whitney U tests showed that implicated product lots had significantly (P = 0.0055) higher mean contamination than nonimplicated lots. The corresponding median values were 3.56 log CFU/carcass for implicated lots and 2.72 log CFU/carcass for nonimplicated lots. For frozen retail product, implicated lots were significantly (P = 0.0281) larger than nonimplicated lots. When the time frame was removed, retail product lots containing Campylobacter flaA SVR genotypes also seen in human disease had significantly higher mean and maximum contamination numbers than lots containing no genotypes seen in human disease for both fresh and frozen product. Our results suggest that cases of broiler-borne campylobacteriosis may occur in clusters and that the differences in mean contamination levels may provide a basis for regulatory action that is more specific than a presence-absence standard.
为了研究冰岛零售肉鸡胴体产品批次中观察到的弯曲杆菌污染程度与人类疾病发病率之间是否存在关联，对来自327个单独产品批次的1617株分离菌进行了基因匹配（使用flaA短可变区[SVR]），与289株来自人类弯曲杆菌病病例的分离菌进行匹配，这些病例的发病时间在加工日期后的大约2周内。当肉鸡分离菌和人类分离菌在适当的时间范围内具有基因同一性时，一个零售产品批次被归类为与人类疾病有关。根据该分析结果，有多个与同一加工批次或多个加工批次相关的人类疾病聚集群。对涉及和未涉及的零售产品批次进行了四个批次描述指标的比较：批次大小、流行率、平均污染度和最大污染度（通过直接冲洗平板法测定）。对于新鲜分销的零售产品，曼-惠特尼U检验表明，涉及的产品批次平均污染度显著高于未涉及的批次（P = 0.0055）。涉及批次的相应中位数为3.56 log CFU/胴体，未涉及批次的为2.72 log CFU/胴体。对于冷冻零售产品，涉及的批次显著大于未涉及的批次（P = 0.0281）。当去除时间范围因素后，对于新鲜和冷冻产品，含有在人类疾病中也可见的弯曲杆菌flaA SVR基因型的零售产品批次的平均污染度和最大污染度显著高于不含有在人类疾病中未见基因型的批次。我们的结果表明，肉鸡传播的弯曲杆菌病病例可能成簇发生，平均污染水平的差异可能为比存在-不存在标准更具针对性的监管行动提供依据。
