1993-2008年禽源大肠杆菌和沙门菌对喹诺酮类药物耐药性分析

目的了解上世纪90年代以来我国部分地区禽源大肠杆菌和沙门菌分离株对1-4代喹诺酮类药物耐药情况。方法血清型采用常规的凝集试验进行测定;药敏纸片试验采用CLSI(clinical and laboratory standards institute)推荐的K-B药敏纸片法。结果344株禽源大肠杆菌分离株覆盖了27个血清型,其中O78、O2、O1和O18血清型菌株分别有141、47、27和22株,共237株,占定型菌株的68.90%;224株禽源沙门菌经血清型鉴定均为鸡白痢沙门菌。1993-1999年禽源大肠杆菌分离株仅对萘啶酸的耐药率超过60%(62.43%,113/181);2000-2008年禽源大肠杆菌分离株对1-3代9种喹诺酮类药物的耐药率均超过60%;禽源沙门菌从2000年起开始出现喹诺酮类耐药菌株,2000-2008年分离到的沙门菌对萘啶酸的耐药率达到了83.74%,但对其它喹诺酮类抗生素的耐药率相对较低。结论近20年来,我国禽源大肠杆菌和沙门菌对喹诺酮类药物的耐药性不断上升,10种喹诺酮类药物之间存在着不同程度的交叉耐药性,且禽源大肠杆菌比沙门菌对喹诺酮类药物的耐药性更为严重,交叉耐药情况亦更为复杂。

The analysis of quinolone resistance of the avian Escherichia coli and Salmonella isolates from 1993 to 2008

Quinolones are broad-spectrum antibacterial agents used in human and veterinary medicine, and their extensive use have been associated with a rise of the quinolone resistance. In the present study, the quinolone resistance of avian E. coli and Salmonella isolates was evaluated and compared, in which 344 avian E. coli and 224 Salmonella isolates from 1990s were serogrouped with antisera and thc antimicrobial susceptibility test to 10 quinolones was carried out by using the Kirby- Bauer method recommended by Clinical and Laboratory Standards Institute （CLSI）. It was demonstrated that the 344 isolates of avian E. coli distributed in 27 serogroups and 68.90% （237/344） of the isolates belonged to four O-serogroups： i.e. 01, 02, 018, 078, and the 224 isolates of avian Salmonella were all determined to be Salmonella pullorum. The drug-resistance rate of avian E. coli isolates to nalicixic acid from 1993--1999 was more than 60%（64. 43%,131/181）, whereas those of isolates to 9 antibiotics from 2000-2008 had a drug-resistance rates of more than 60%, namely,nalicixic acid（92.02%）, fleroxacin（79.75 % ）, pipemidic acid （79.14 % ）, enrofloxacin（78.53 % ）, enoxacin（ 76.07 % ）, lomenfloxacin（ 74.85 % ）, ciprofloxaein （69.33%）, norfloxacin（63.80%） and ofloxacin（61.35%）. For the 4 O-serogroups of the avian E. coli isolates, the drug-resistance rates of more than 50% to antimicrobials were as follows： 078 isolates to 7 antimicrobials; O18 isolates to 5 antimierobials, and O1 and O2 isolates just to 3 antimicrobials. The quinolone resistance of Salmonella isolates was much lower than E. coli, in which 101 salmonella isolates from 1993--1999 were all susceptible to quinolones. Nalicixic acid resistance of salmo- nella isolate firstly appeared in 2000, and the drug-resistance rate of salmonella isolates from 2000- 2008 was found to be more than 60 % for nalicixic acid（83.74%）, but those to other quinolones were comparatively lower. These results indicated that the quinolone resis