北京地区2006～2007年霍乱弧菌耐药状况及霍乱毒素基因的研究

A study on antibiotic resistance and virulence gene of Vibrio cholerae in Beijing from 2006 to 2007

目的了解北京地区2006～2007年O1群和O139群霍乱弧菌耐药性和霍乱毒素(cholera toxin,CT)基因的特征,探讨其耐药特征与CT基因和菌种来源的关系。方法用PCR方法检测124株霍乱弧菌CT基因;用WHO推荐的改良K-B纸片法,对所有菌株进行5种常用抗菌药物的药敏试验;用卡方检验对结果进行统计学分析。结果124株O1群和O139群霍乱弧菌对诺氟沙星和环丙沙星的敏感率均达85%以上。103株O1群霍乱弧菌中,21株CT阳性的O1群霍乱弧菌对丁胺卡那的耐药率为81%,82株CT阴性的O1群霍乱弧菌的耐药率为4.9%;59株外环境来源的O1群霍乱弧菌对丁胺卡那的耐药率为33.9%,44株人源性的O1群霍乱弧菌对其耐药率为2.3%。21株O139群霍乱弧菌中,6株CT阳性的O139群霍乱弧菌对强力霉素的耐药率为66.7%,15株CT阴性的O139群霍乱弧菌对其耐药率为13.3%;10株外环境来源的O139群霍乱弧菌对强力霉素的耐药率为60%,11株人源性的O139群霍乱弧菌对其耐药率为9.1%。经卡方检验,以上差异均有统计学意义(P<0.05)。结论诺氟沙星和环丙沙星对霍乱弧菌有较高的敏感性,可以作为霍乱防治的首选药物。霍乱弧菌对部分抗生素的耐药特征与CT基因和菌种来源有一定的关系。

Objective To investigate the characteristics of antibiotic resistance and cholera toxin （CT） genes of Vibrio cholera and discuss the relationships between antibiotic resistance and CT genes and ori- gin of Vibrio cholera. Methods CT genes of 124 Vibrio cholera isolates were detected by PCR. Antibiotics susceptibility test was also performed against 5 kinds of antibiotics in common use with Kirby-Bauer method, which was introduced by WHO. The experiment results were analyzed by statistic method. Results Among the 124 Vibrio cholera O1 and Vibrio cholera O139 isolates, over 85 percent were sensitive to Norfloxacin and Ciprofloxacin. Among the 103 Vibrio cholera O1 isolates, the drug resistant rate of 21 isolates with CT genes a- gainst Amikacin was 81% and the remained 82 isolates without CT genes against Amikacin was 4.9%. Among the 103 Vibrio cholera O1 isolates, the drug resistant rate of 59 environmental isolates against Amikacin was 33.9% and the remained 44 clinical isolates against Amikacin was 2.3%. Among the 21 Vibrio cholera O139 isolates, the drug resistant rate of 6 isolates with CT genes against Doxycycline was 66.7% and the remained 15 isolates without CT genes was 13.3%. Among the 21 Vibrio cholera O139 isolates, the drug resistant rate of 10 environmental isolates against Doxycycline was 60% and the remained 11 clinical isolates was 9.1%. The statistical significance of the above resuhs have been showed at the 95% level （P 〈0. 05）. Conclusions Vibrio cholera exhibit high sensitivity to Norfloxacin and Ciprofloxacin and may be the first choice in the treat- ment and prevention against cholera. The drug resistance feature of Vibrio cholera against some of the antibiotics are related with the CT genes and the origin of the isolates.