Ransom J R, Belk K E, Bacon R T, Sofos J N, Scanga J A, Smith G C
Center for Red Meat Safety, Department of Animal Sciences, Colorado State University, Fort Collins 80523-1171, USA.
J Food Prot. 2002 Apr;65(4):621-6. doi: 10.4315/0362-028x-65.4.621.
This study compared sampling methods for detecting Escherichia coli O157:H7 and Salmonella in beef cattle feces and on hides and carcasses and for enumerating E. coli biotype I counts (ECC) on carcasses. Fecal samples were collected by rectal/colonal palpation and colonal sponge swabbing. Hides were sampled by sponge swabbing three sites, hair clipping, excision, rinsing, and gauze swabbing, whereas carcasses were sampled by three-site thoracic and pattern-mark sponge swabbing and tissue excision. Overall, irrespective of sampling method, 36.7, 13.3, and 0.0% of lots contained at least one E. coli O157:H7-positive hide, fecal, and carcass sample, respectively, while the corresponding prevalence of Salmonella was 70.0, 16.7, and 6.7%, respectively. For hide sampling, excision and gauze swabbing yielded the fewest (13.3%) E. coli O157:H7-positive samples, while hair clipping and sponge swabbing yielded the most (23.3%). None of the carcass-sampling methods detected E. coli O157:H7 or differed (P > 0.05) in their ability to enumerate ECC. Colonal swabbing was the most effective (10.0%) method for detecting E. coli O157:H7 in feces. No differences (P > 0.05) in Salmonella prevalence were observed between carcass-sampling methods, although three-site sponge swabbing and tissue excision detected the most (3.3%). Hide rinsing was the most effective (P < 0.05) Salmonella detection method (63.3%), but dangers associated with its application may preclude its use by industry; there were no differences (P > 0.05) among other hide-sampling methods. No differences (P > 0.05) in Salmonella detection were observed between fecal-sampling methods. Overall, three-site sponge swabbing was the most feasible and effective sampling method for the detection of E. coli O157:H7 and Salmonella on hides and carcasses.
本研究比较了用于检测肉牛粪便、皮张和胴体中大肠杆菌O157:H7和沙门氏菌以及用于计数胴体上大肠杆菌I型菌数（ECC）的采样方法。粪便样本通过直肠/结肠触诊和结肠海绵拭子采集。皮张通过在三个部位进行海绵拭子采样、剪毛、切除、冲洗和纱布拭子采样，而胴体通过在三个部位进行胸部和图案标记海绵拭子采样以及组织切除采样。总体而言，无论采用何种采样方法，分别有36.7%、13.3%和0.0%的批次至少含有一份大肠杆菌O157:H7阳性的皮张、粪便和胴体样本，而沙门氏菌的相应检出率分别为70.0%、16.7%和6.7%。对于皮张采样，切除和纱布拭子采样产生的大肠杆菌O157:H7阳性样本最少（13.3%），而剪毛和海绵拭子采样产生的阳性样本最多（23.3%）。没有一种胴体采样方法检测到大肠杆菌O157:H7，并且在计数ECC的能力方面没有差异（P>0.05）。结肠拭子采样是检测粪便中大肠杆菌O157:H7最有效的方法（10.0%）。在胴体采样方法之间，沙门氏菌检出率没有差异（P>0.05），尽管在三个部位进行海绵拭子采样和组织切除检测到的沙门氏菌最多（3.3%）。皮张冲洗是最有效的（P<0.05）沙门氏菌检测方法（63.3%），但其应用相关的风险可能使行业无法采用；其他皮张采样方法之间没有差异（P>0.05）。在粪便采样方法之间，沙门氏菌检测没有差异（P>0.05）。总体而言，在三个部位进行海绵拭子采样是检测皮张和胴体上大肠杆菌O157:H7和沙门氏菌最可行且有效的采样方法。
