Study On Serotype And Drug Resistance Of Group B Streptococcus Carried By Women In Perinatal Period

Objective:In order to understand the serotypes of group B streptococcus(GBS)carried by perinatal women in central Jiangxi and their resistance to commonly used antibacterial drugs,and to observe the pregnancy outcome of pregnant women infected with different GBS serotypes.Method:The genital tract secretions of 10145 hospitalized pregnant women from Jiangxi Province Maternal and Child Health Hospital from June to November 2019 were collected for routine culture,and the VITEK 2 system was used to identify the strains and the supporting drug sensitivity card for drug sensitivity testing.The detected group B streptococci were used to amplify the capsular genes cps D,E,F,G,H,I,J,K,L,M,N,and O by multiplex PCR method for serotyping.Result:A total of 10145 samples of genital tract secretions of pregnant women were collected this time and routinely isolated and cultured.A total of 149 strains of GBS were detected,with the positive rate of 1.47%.The age of pregnant women was20-42 years old with an average of(29.41±3.25)years old.Among pregnant women were eighty-three women of right age(<35 years old),accounting for 88.30%,and eleven women of advanced age(≥35 years),accounting for 11.70%,and twenty-two premature pregnant women(<37 weeks),accounting for 23.40%,and seventy-two full-term pregnant women(≥37 weeks),accounting for 76.60%,and fity first-time pregnant women,accounting for 53.19%,and forty-four pregnant women with multiple pregnancies,accounting for 46.81%.Nature labour women accounted for56.38%,and 43.62% pregnant women were underwent a cesarean section.Among the newborns,there were ninety-seven live births,fifty-six boys,accounting for57.73%,weighing 2.99±0.66 g,and forty-one girls,weighing 3.00±0.63 g,and five stillbirths,accounting for 4.90%.The GBS carried by 94 pregnant women was successfully divided into 7serotypes by amplifying the capsular genes cps D,E,F,G,H,I,J,K,L,M,N,and O.33 strains of type Ib(35.11%),25 strains of type III(26.60%),22 strains of type Ia(23.40%),and 5 strains of type V(5.32%),4 strains each of type II and VI(4.26%),and 1 strain of type IX(1.06%).No types IV,VII,and VIII were detected.Serotype complicated with pregnancy complications,including 13 cases(13.83%)of serotype Ia complicated with pregnancy complications,10 cases(10.64%)of type Ib complicated pregnancy complications,8 cases(8.51%)of type III complicated pregnancy complications,others 4 cases of serotype(4.26%).Comparing serotype Ia and Ib with pregnancy complications,p <0.05,and the difference is statistically significant.The GBS serotypes isolated in pregnant women who cause premature delivery and intrauterine infection are mainly type III and Ia.GBS that cause premature rupture of membranes are mainly type Ia and Ib.It causes fetal distress and even stillbirth,which is of type III,Ib and Ia.The rate of complications of premature rupture of membranes is 13.83%(13/94),and the stillbirth rate is as high as 4.90%(5/102).The resistance results of 94 GBS strains have higher resistance rates to clindamycin(81.91%),erythromycin(79.79%)and tetracycline(65.96%),followed by levofloxacin(41.49%)and moxifloxacin(27.66%).All GBS strains were 100%sensitive to penicillin,ampicillin,linezolid,vancomycin and quinupridine/dalfopristin.The results of the GBS drug susceptibility test on 8 categories and 10 antibiotics showed that 6 strains(6.38%)were fully sensitive to 8 categories of antibiotics,18 strains(19.15%)were resistant to one or two antibiotics.70 strains(74.47%)were multi-drug resistant,and GBS was mainly resistant to clindamycin,erythromycin and tetracycline at the same time.Conclusion:The colonization rate of GBS carried by perinatal women in central Jiangxi is1.47%,which is slightly lower than the colonization rate of GBS carried by pregnant women nationwide.The serotypes of GBS strains carried by pregnant women in central Jiangxi are mainly Ib and III,followed by Ia.But type Ia has a higher incidence of pregnancy complications than other serotypes.These GBS stains of bacterial resistance and multi-drug resistance are relatively serious,but they are still100.00% sensitive to penicillin,ampicillin and vancomycin.