深圳市婴儿感染B族链球菌的克林霉素诱导型耐药研究

Inducible Resistance to Clindamycin in Group B Streptococcus Isolated from Infants in Shenzhen

目的:了解婴儿感染B族链球菌(GBS)的红霉素、克林霉素耐药率及大环内酯-林可酰胺-链阳菌素B(MLSB)类抗菌药物耐药表型。方法:采用纸片扩散法检测婴儿感染GBS菌株对红霉素、克林霉素的敏感性,D试验检测红霉素对克林霉素的诱导耐药性。结果:本研究纳入的患儿中男16例,女15例,年龄3 h^5个月。GBS对红霉素、克林霉素的耐药率分别为80.6%、77.4%;对红霉素、克林霉素同时敏感的GBS 3株,占9.7%;对红霉素耐药、对克林霉素敏感的2株,占6.5%。23例(92.0%)内在型耐药(cMLSB),2例(8.0%)M型耐药,未发现诱导型耐药。结论:婴儿感染的B族链球菌对红霉素、克林霉素耐药率高,MLSB耐药表型以cMLSB为主,未发现诱导型耐药。

Objective： To explore the resistance rate of group B Streptococcus （GBS） to erythromycin and clindamycin and phenotype of resistance to macrolides, lincosamides and type B streptogramin （MLSB）in infected infants. Methods： The antimicrobial susceptibility of GBS to erythromycin and clindamycin were determined by the disk diffusion technique in Mueller-Hinton agar. The inducible resistance of erythromycin to elindamyein was detected by D test. Results： Thirty one strains were isolated from 31 children （16 boys, 15 girls）. The ages ranged from 3 h to 5 months. Among the 31 GBS-positive cultures, erythromycin resistance was found in 25 strains （80. 6% ） , clindamycin resistance was found in 24 strains （77.4%）. Three GBS isolates were susceptible to both erythromyein and clindamycin. Two isolates were resistant to erythromyein whilst susceptible to clindamycin. Among the 25 erythromycin-resistant isolates, the constitutive MLSB （eMLSB） was indentified in 23 eases（92.0% ）. The iMLSB phenotype was not found. Conclusion： Rates of GBS resistance to erythromycin and clindamycin in infants are high. The eMLSB phenotype is common and iMLSB is not found.