Agga Getahun E, Arthur Terrance M, Hinkley Susanne, Bosilevac Joseph M
1 U.S. Department of Agriculture, Agricultural Research Service, Roman L. Hruska U.S. Meat Animal Research Center, Clay Center, Nebraska 68933; and.
2 Neogen Corporation, NeoSEEK Laboratory, 4131 North 48th Street, Lincoln, Nebraska 68504, USA.
J Food Prot. 2017 Apr;80(4):661-667. doi: 10.4315/0362-028X.JFP-16-435.
Cattle are a primary reservoir of enterohemorrhagic Escherichia coli (EHEC), and contaminated beef products are a source of human infections. The U.S. Department of Agriculture Food Safety and Inspection Service declared seven EHEC serogroups (O26, O45, O103, O111, O121, O145, and O157) as adulterants in raw ground beef. Sampling a large number of animals for EHEC surveillance or evaluations of EHEC-focused preharvest interventions requires a convenient and robust sampling method. We evaluated the diagnostic performance of rectoanal mucosal swab (RAMS) for the detection of the top seven EHEC serogroups. Paired fecal grab (FG) and RAMS samples were collected from 176 beef cattle and tested using the NeoSEEK Shiga toxin-producing E. coli (STEC) confirmation method. The prevalence of virulence-associated genes (stx, stx, stx, eae, and nleB) was higher in RAMS than in FG samples. The results of the two methods had poor agreement, as indicated by kappa statistics, for the detection of the seven serogroups. When FG and RAMS results were combined for comparison, RAMS was more sensitive than FG for the detection of serogroups O103 (82% versus 39%), O157 (75% versus 67%), and O45 (79% versus 73%) with similar sensitivity for the detection of serogroup O145 (67%). Serogroups O111 and O121 were detected from one and two samples, respectively, by FG and were not detected by RAMS. Serogroup O26 was not detected with either method. RAMS appears to be equivalent or superior to FG sampling for detection of the top seven EHEC serogroups in the feces of beef cattle with the NeoSEEK STEC confirmation test.
牛是肠出血性大肠杆菌（EHEC）的主要宿主，受污染的牛肉产品是人类感染的来源。美国农业部食品安全与检验局宣布，七种EHEC血清型（O26、O45、O103、O111、O121、O145和O157）为生牛肉末中的掺假物质。对大量动物进行EHEC监测或评估以EHEC为重点的收获前干预措施需要一种方便且可靠的采样方法。我们评估了直肠肛门黏膜拭子（RAMS）对七种主要EHEC血清型的检测诊断性能。从176头肉牛中采集配对的粪便抓取样本（FG）和RAMS样本，并使用NeoSEEK产志贺毒素大肠杆菌（STEC）确认方法进行检测。RAMS样本中毒力相关基因（stx、stx、stx、eae和nleB）的流行率高于FG样本。kappa统计表明，两种方法在检测这七种血清型时一致性较差。当将FG和RAMS结果合并进行比较时，RAMS在检测O103血清型（82%对39%）、O157血清型（75%对67%）和O45血清型（79%对73%）时比FG更敏感，检测O145血清型时敏感性相似（67%）。FG分别从1个和2个样本中检测到O111和O121血清型，而RAMS未检测到。两种方法均未检测到O26血清型。对于使用NeoSEEK STEC确认试验检测肉牛粪便中七种主要EHEC血清型，RAMS似乎等同于或优于FG采样。
