B群链球菌耐药性及红霉素耐药机制的研究  

Susceptibility patterns and mechanisms of erythromycin resistance in group B streptococcus isolates

作　　者：周义正[1] 李高莲[1] 邱晓燕[1] 王昌富[1] 

机构地区：[1]荆州市中心医院检验科,湖北荆州434020

出　　处：《中国微生态学杂志》2011年第1期66-68,共3页Chinese Journal of Microecology

摘　　要：目的探讨荆州地区GBS对常用抗生素的耐药谱和对红霉素的耐药机制。方法采用选择性培养法从阴道和肛门拭子中分离B群链球菌(GroupB Streptococci,GBS),用标准的K-B法对常用的7种抗生素进行药敏试验,然后针对红霉素耐药菌株检测耐药基因ermA、ermB和mefA。结果 176株GBS对头孢噻肟和万古霉素均敏感,对青霉素和氨苄青霉素虽然没有耐药但其中介率达到12.0%。对红霉素的耐药率和中介率分别为35.8%和6.8%;对克林霉素的耐药率和中介率分别为9.5%和12.5%。63株对红霉素耐药的GBS中有22株同时对克林霉素耐药(cMLS型),有41株对红霉素耐药而对克林霉素敏感(M型)。在22株cMLS型耐药的菌株中有18株检测到ermB基因,2株检测到检测到ermA基因。在M型耐药的菌株中有32株检测到mefA基因,6株检测到ermB基因,1株检测到检测到ermA基因。结论青霉素是治疗本地区GBS感染的有效药物,但本地区GBS对红霉素的耐药比较严重。mefA介导的外排机制可能是是本地区分离的GBS对红霉素耐药的主要机制。Objective To explore the antibiotic susceptibility and mechanisms of erythromycin resistance in group B streptococcus （GBS） isolated from Samples in Jingzhou. Method GBS were isolated from vagina swabs and anal swabs by selective method. GBS positive cultures were tested for their resistance to seven antibiotics by K-B method. Gene ermA, ermB and mefA were detected in isolates resistant to erythromycin. Result Susceptibility testing revealed that none of the GBS isolates were resistant to cefotaxime and vancomycin, but 12% of the isolates showed intermediate susceptibility to penicillin G and ampicillin. The rates of erythromycin resistance and intermediate were 35.8% and 6.8% respectively. The rate of clindamycin resistance and intermediate were 9.5% and 12.5% respectively. 22 strains of GBS were resistant to erythromyein and clindamycin（cMLS phenotpye）. Gene ermB was detected in 18 strains of cMLS phenotpye. Gene ermA was detected in 2 strains of eMLS phenotpye. 41 strains of GBS were resistant to exythromycin but susceptible to elindamy- cin（M phenotpye）. Gene ermB was detected in 6 strains of M phenotpye. Gene ermA was detected in 1 strain of M phe- notpye. Gene mefA was detected in 32 strains of M phenotpye. Conclusion Penicillin is an effective drug to GBS infec- tion in the region, but the region＇s GBS resistance to erythromycin is more serious. The mefA-mediated ettlux mechanism may be the main mechanism of erythromycin resistance in the GBS isolated from this region.

关 键 词：B群链球菌 耐药性 基因 

分 类 号：R378.12[医药卫生—病原生物学]