Study On Resistance And Resistant Genes Of Group B Streptococcus From Perinatal Women In Shijiazhuang During 2014

Objective:1 To analyze the prevalence and the drug resistance of Group B streptococcus in Shijiazhuang district, and providing guidance for Clinical rational drug use.2 Using PCR to amplify Group B streptococcus genes and confirm its gene types, to grasp molecular epidemiological characteristics of Group B streptococcus in Shijiazhuang district.Methods:1 Source of strainsNon-repetitive Group B streptococcus strains which were isolated from the vaginal secretion of 34~37 weeks of pregnant woman were collected.2 Identify and Antibiotic susceptibility testGroup B streptococcus were detected by Mellier ATB bacterial identification instrument and CAMP test.Antibiotic susceptibility was confirmed by K-B method according to CLSI M100-S23(2013) standards.3 Detection of resistant gene6 related to Group B streptococcus Erythomycin resistant genes were detected by PCR technique. The products were detected by electrophoresis and observed by UV Gel imaging system. The gene molecular size bands are same as positive and save the image photography.4 DNA sequencing analysisPCR products of 2~4 strains random from the groups mre A、mef A、erm A、erm B and mef E were sequenced by sequencing company. The sequence results were blasted in Gen Bank to ascertain the subtypes.Results: 1 Detection rate of Group B Streptococcus3504 specimen were cultured which collected from the vaginal secretion of 34~37 weeks of pregnant woman from the fourth hospital of Shijiazhuang in the year of 2014.The detection rate is 2.74% and isolated 96 strains was Group B Streptococcus.2 Atibiotic susceptibility test resultIn the, 96 strains Group B Streptococcus. were tested for Antibiotic susceptibility to 14 kinds of clinical antibiotics.(1)Ceftriaxone,Piperacillin,Piperacillin-Tazobactam,Cefperazone-Sulbactam,Cefamandole,Cefathiamidine all were sensitive.(2) Amoxycillin-Clavulanie acid, Ampicillin-Sulbactam, Cefazolin, Cefuroxime,Penicillin,some had been appeared, resistance rate were 3.13 %,2.08%,2.08%,1.04%,1.04%.(3) Erythromycin,Clindamycin,Azithromycin had been appeared,the high risistance rate were 78.13%,75%,79.17%.3 Results of resistant gene detectionAmong 75 strains of Group B Streptococcus, the detection rates of Erythromycin resistant genes(mre A, mef A, erm A, erm B and erm E) were 94.67%,44.00%,2.67%,73.33%,40.00%; no strains tested erm C.Among them, 1(1.33%)strains didn’t carry resistant gene,7(9.33%) carried 1 kind,35(46.67%)carried 2 kinds,1(20.00%)carried 3 kinds,16(21.33%)carried 4 kinds and 1(1.33%)carried 5 kinds of resistant genes.4 Genes sequencing resultsThe resistant genes of mre A,mef A,erm A,erm B and mef E were sequenced. The nucleotide homology with that of reference strains in Gen Bank was 100%, without gene mutation.Conclusions:1 Detection rate of Group B streptococcus from vaginal secretion of pregnant women in Shijiazhuang district 2014 is 2.74%, and appeared serious drug resistance to Erythromycin,Clindamycin,Azithromycin.2 The positive rate of Group B Streptococcus resistant genes were detected,which are mre A,erm B,mef A,mef E and erm A types from high to low.3 The nucleotide sequence homology of five resistant genotypes(mre A,mef A,erm A,erm B and mef E) is 100% with that of reference strains in Gen Bank.4 The hospital should strengthen the monitor of drug resistance and the resistance genes among Group B streptococcus, so that it would guide scientific and effective use of antimicrobial drugs.