U.S. Department of Agriculture, National Wildlife Research Center, Fort Collins, CO, USA.
U.S. Department of Agriculture, National Wildlife Research Center, Fort Collins, CO, USA.
J Microbiol Methods. 2020 May;172:105892. doi: 10.1016/j.mimet.2020.105892. Epub 2020 Mar 14.
A method was developed and validated for the detection of colistin-resistant Escherichia coli containing mcr-1 in the feces of feral swine. Following optimization of an enrichment method using EC broth supplemented with colistin (1 μg/mL) and vancomycin (8 μg/mL), aliquots derived from 100 feral swine fecal samples were spiked with of one of five different mcr-1 positive E. coli strains (between 10 and 10 CFU/g), for a total of 1110 samples tested. Enrichments were then screened using a simple boil-prep and a previously developed real-time PCR assay for mcr-1 detection. The sensitivity of the method was determined in swine feces, with mcr-1 E. coli inocula of 0.1-9.99 CFU/g (n = 340), 10-49.99 CFU/g (n = 170), 50-99 CFU/g (n = 255), 100-149 CFU/g (n = 60), and 200-2200 CFU/g (n = 175), which were detected with 32%, 72%, 88%, 95%, and 98% accuracy, respectively. Uninoculated controls (n = 100) were negative for mcr-1 following enrichment.
建立并验证了一种检测粪便中携带 mcr-1 的耐药大肠埃希菌的方法。在使用添加多粘菌素（1μg/mL）和万古霉素（8μg/mL）的 EC 肉汤对富集方法进行优化后，从 100 份野猪粪便样本中提取等分试样，然后分别接种五种不同 mcr-1 阳性大肠埃希菌菌株（10 到 10 CFU/g）中的一种，总共测试了 1110 个样本。然后，使用简单的煮沸预处理和先前开发的实时 PCR 检测 mcr-1 的方法对富集物进行筛选。该方法在猪粪便中的灵敏度如下：0.1-9.99 CFU/g（n=340）、10-49.99 CFU/g（n=170）、50-99 CFU/g（n=255）、100-149 CFU/g（n=60）和 200-2200 CFU/g（n=175）的 mcr-1 大肠埃希菌接种物的检测准确率分别为 32%、72%、88%、95%和 98%。100 个未接种对照样本（n=100）在富集后 mcr-1 均为阴性。
