Singh Pallavi, Sha Qiong, Lacher David W, Del Valle Jacquelyn, Mosci Rebekah E, Moore Jennifer A, Scribner Kim T, Manning Shannon D
Department of Microbiology and Molecular Genetics, Michigan State University East Lansing, MI, USA.
Division of Molecular Biology, Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration Laurel, MD, USA.
Front Cell Infect Microbiol. 2015 Apr 1;5:29. doi: 10.3389/fcimb.2015.00029. eCollection 2015.
Shiga toxin-producing Escherichia coli (STEC) is an important foodborne pathogen. Cattle are suggested to be an important reservoir for STEC; however, these pathogens have also been isolated from other livestock and wildlife. In this study we sought to investigate transmission of STEC, enterohemorrhagic E. coli (EHEC) and enteropathogenic E. coli (EPEC) between cattle and white-tailed deer in a shared agroecosystem. Cattle feces were collected from 100 animals in a Michigan dairy farm in July 2012, while 163 deer fecal samples were collected during two sampling periods (March and June). The locations of deer fecal pellets were recorded via geographic information system mapping and microsatellite multi-locus genotyping was used to link the fecal samples to individual deer at both time points. Following subculture to sorbitol MacConkey agar and STEC CHROMagar, the pathogens were characterized by serotyping, stx profiling, and PCR-based fingerprinting; multilocus sequence typing (MLST) was performed on a subset. STEC and EHEC were cultured from 12 to 16% of cattle, respectively, and EPEC was found in 36%. Deer were significantly less likely to have a pathogen in March vs. June where the frequency of STEC, EHEC, and EPEC was 1, 6, and 22%, respectively. PCR fingerprinting and MLST clustered the cattle- and deer-derived strains together in a phylogenetic tree. Two STEC strains recovered from both animal species shared MLST and fingerprinting profiles, thereby providing evidence of interspecies transmission and highlighting the importance of wildlife species in pathogen shedding dynamics and persistence in the environment and cattle herds.
产志贺毒素大肠杆菌(STEC)是一种重要的食源性病原体。牛被认为是STEC的重要宿主;然而,这些病原体也已从其他家畜和野生动物中分离出来。在本研究中,我们试图调查在共享农业生态系统中牛和白尾鹿之间STEC、肠出血性大肠杆菌(EHEC)和肠致病性大肠杆菌(EPEC)的传播情况。2012年7月从密歇根州一个奶牛场的100头牛中采集粪便样本,同时在两个采样期(3月和6月)采集了163份鹿粪便样本。通过地理信息系统绘图记录鹿粪便颗粒的位置,并使用微卫星多位点基因分型在两个时间点将粪便样本与个体鹿联系起来。在接种到山梨醇麦康凯琼脂和STEC显色培养基上进行继代培养后,通过血清分型、stx分型和基于PCR的指纹图谱对病原体进行鉴定;对一部分样本进行多位点序列分型(MLST)。分别从12%至16%的牛中培养出STEC和EHEC,36%的牛中发现了EPEC。与6月相比,3月鹿携带病原体的可能性显著降低,其中STEC、EHEC和EPEC的检出率分别为1%、6%和22%。PCR指纹图谱和MLST在系统发育树中将牛源和鹿源菌株聚集在一起。从两种动物中分离出的两种STEC菌株具有相同的MLST和指纹图谱,从而提供了种间传播的证据,并突出了野生动物物种在病原体排放动态以及在环境和牛群中持续存在方面的重要性。