Lim Suk-Kyung, Lim Keum-Gi, Lee Hee-Soo, Jung Suk-Chan, Kang Mun-Il, Nam Hyang-Mi
National Veterinary Research and Quarantine Service, Ministry of Agriculture and Forestry, 480 Anyang, Kyonggido, Republic of Korea.
J Vet Med Sci. 2010 May;72(5):611-4. doi: 10.1292/jvms.08-0302. Epub 2009 Dec 15.
A total of 176 E. coli isolates were retrieved from 203 diarrheic fecal samples collected from Korean cattle on 117 different farms. The most frequently observed resistance in E. coli isolates was to tetracycline (88.6%), followed by streptomycin (80.7%) and ampicillin (64.8%). Resistance to cefazolin, cefoperazone, cefepime and amikacin was very low. Of the 176 E. coli strains, forty (22.7%) isolates from 30 farms showed resistance to fluoroquinolones (FQ). All the FQ-resistant strains possessed double mutations at codons 83 and 87 in the gyrA gene, and a single mutation mostly at codon 80 in the parC gene, except in one isolate. The pulsed-field gel electrophoresis profiles of the FQ-resistant E. coli isolates were heterogeneous, but two or three isolates that showed an identical pattern originated from the same or different farms. This study demonstrates that FQ resistance is frequently observed in E. coli from diarrheic cattle and that mutations in the quinolone resistance-determining region are the same as those seen in E. coli originating from other animal species and humans. The FQ resistance in diarrheic cattle might have been mostly acquired independently, although the possibility of transmission of FQ-resistant E. coli within a farm or between farms is plausible.
从117个不同农场的203份韩国肉牛腹泻粪便样本中总共分离出176株大肠杆菌。大肠杆菌分离株中最常见的耐药性是对四环素（88.6%），其次是链霉素（80.7%）和氨苄青霉素（64.8%）。对头孢唑林、头孢哌酮、头孢吡肟和阿米卡星的耐药性非常低。在176株大肠杆菌菌株中，来自30个农场的40株（22.7%）分离株对氟喹诺酮类（FQ）耐药。除一株分离株外，所有FQ耐药菌株在gyrA基因的83和87密码子处都有双重突变，在parC基因中大多在80密码子处有单一突变。FQ耐药大肠杆菌分离株的脉冲场凝胶电泳图谱是异质性的，但显示相同图谱的两株或三株分离株来自同一个或不同的农场。本研究表明，腹泻牛的大肠杆菌中经常观察到FQ耐药性，喹诺酮耐药决定区的突变与来自其他动物物种和人类的大肠杆菌中观察到的突变相同。腹泻牛的FQ耐药性可能大多是独立获得的，尽管FQ耐药大肠杆菌在农场内或农场间传播的可能性是存在的。
