Sayah Raida S, Kaneene John B, Johnson Yvette, Miller RoseAnn
Population Medicine Center, A-109 Veterinary Medical Center, Michigan State University, East Lansing, MI 48824-1314, USA.
Appl Environ Microbiol. 2005 Mar;71(3):1394-404. doi: 10.1128/AEM.71.3.1394-1404.2005.
A repeated cross-sectional study was conducted to determine the patterns of antimicrobial resistance in 1,286 Escherichia coli strains isolated from human septage, wildlife, domestic animals, farm environments, and surface water in the Red Cedar watershed in Michigan. Isolation and identification of E. coli were done by using enrichment media, selective media, and biochemical tests. Antimicrobial susceptibility testing by the disk diffusion method was conducted for neomycin, gentamicin, streptomycin, chloramphenicol, ofloxacin, trimethoprim-sulfamethoxazole, tetracycline, ampicillin, nalidixic acid, nitrofurantoin, cephalothin, and sulfisoxazole. Resistance to at least one antimicrobial agent was demonstrated in isolates from livestock, companion animals, human septage, wildlife, and surface water. In general, E. coli isolates from domestic species showed resistance to the largest number of antimicrobial agents compared to isolates from human septage, wildlife, and surface water. The agents to which resistance was demonstrated most frequently were tetracycline, cephalothin, sulfisoxazole, and streptomycin. There were similarities in the patterns of resistance in fecal samples and farm environment samples by animal, and the levels of cephalothin-resistant isolates were higher in farm environment samples than in fecal samples. Multidrug resistance was seen in a variety of sources, and the highest levels of multidrug-resistant E. coli were observed for swine fecal samples. The fact that water sample isolates were resistant only to cephalothin may suggest that the resistance patterns for farm environment samples may be more representative of the risk of contamination of surface waters with antimicrobial agent-resistant bacteria.
开展了一项重复横断面研究，以确定从密歇根州红杉河流域的人类污水、野生动物、家畜、农场环境和地表水分离出的1286株大肠杆菌的耐药模式。通过使用增菌培养基、选择性培养基和生化试验进行大肠杆菌的分离和鉴定。采用纸片扩散法对新霉素、庆大霉素、链霉素、氯霉素、氧氟沙星、甲氧苄啶-磺胺甲恶唑、四环素、氨苄西林、萘啶酸、呋喃妥因、头孢噻吩和磺胺异恶唑进行药敏试验。家畜、伴侣动物、人类污水、野生动物和地表水的分离株均表现出对至少一种抗菌药物的耐药性。一般来说，与人类污水、野生动物和地表水的分离株相比，来自家养物种的大肠杆菌分离株对最多数量的抗菌药物耐药。耐药性最常见的药物是四环素、头孢噻吩、磺胺异恶唑和链霉素。按动物分类，粪便样本和农场环境样本的耐药模式存在相似性，农场环境样本中头孢噻吩耐药分离株的水平高于粪便样本。在多种来源中均发现了多重耐药性，猪粪便样本中多重耐药大肠杆菌的水平最高。水样分离株仅对头孢噻吩耐药这一事实可能表明，农场环境样本的耐药模式可能更能代表地表水被耐药菌污染的风险。
