Streptococcus agalactiae:Sensitivity profile in pregnant women attending health units in northeastern Brazil

BACKGROUNDG roup B Streptococcus agalactiae (GBS) is the main etiologic agent associated withearly-onset neonatal sepsis, and of all newborns of parturients colonized by GBS,approximately 1%-2% develop invasive, early-onset disease. The risk of infectionincreases to 15.2% in premature neonates, to 10.7% when the parturient haschorioamnionitis or premature rupture of membranes for more than 24 h and to9.7% if the mother has postpartum bacteremia. In addition to causing perinatal,neonatal and postnatal deaths, neonatal hospital infection is associated with highcosts, as hospitalization is three times longer than in uninfected children. Theidentification of pregnant women colonized by GBS, through universal screening,associated with the adoption of appropriate antibiotics at the time of delivery arethe most successful preventive measures.AIMTo evaluate the sensitivity profile of GBS isolated from pregnant womenattending Vitória da Conquista-BA.METHODS This is a cross-sectional study with a quantitative approach carried out in themunicipality of Vitória da Conquista-Bahia between February 2017 and March2018. The study population was composed of 210 pregnant women, with agestational age of 32 to 40 wk, who were aged 18 years or older living in the urbanarea of the municipality of Vitória da Conquista. After a brief explanation aboutthe research and obtaining a signed an informed consent form, data andvaginorectal swabs were collected from the women for GBS research. Examinationof the samples in order to identify the presence of GBS was by culture on sheep blood agar and chromogenic agar for GBS and then, seeded on plates containingstreptococcal culture medium and incubated for 18 h to 24 h at 35°C. Theantimicrobial sensitivity profile of positive GBS samples was determined by thedisk diffusion technique, according to the Clinical and Laboratory StandardsInstitute manual (2017). The data obtained were stored in a database usingMicrosoft Office Excel spreadsheets and a descriptive analysis was performedwith the aid of the EPI-INFO statistical package (version 3.5.2).RESULTSAmong the 210 pregnant women participating in the study, 38 (18.1%) had apositive GBS culture. All strains isolated from GBS were sensitive to 10 Upenicillin, 10 μg ampicillin, 30 μg cefotaxime and 30 μg vancomycin. Seven strains(18.4%) resistant to clindamycin 2 μg and eight (21.1%) resistant to erythromycin15 μg were found. Of these, six were concomitantly resistant to erythromycin andclindamycin, two resistant only to erythromycin and one resistant only toclindamycin. All nine GBS isolates that showed resistance to erythromycin and/orclindamycin showed negative results on the D-test. Two thirds of the isolatesshowed cMLSB phenotype and resistance only to erythromycin in specimens inthis study (02), refers to strains with phenotype M and resistance to clindamycin(01) only with phenotype L.CONCLUSIONChemoprophylaxis for GBS in pregnant women, especially for those allergic topenicillin, should be guided by an antimicrobial susceptibility test as resistantGBS strains were reported in this study.

孕妇孕晚期GBS定植及新生儿早发型GBS感染趋势

目的观察孕晚期B族链球菌(GBS)的定植情况以及母婴垂直传播率,评估新生儿早发型GBS疾病(EOD)的发病趋势。方法选择2014年1月至2015年3月在南京医学院附属苏州母子医疗保健中心住院分娩的3487例孕妇进行阴道GBS筛查,根据美国疾病控制中心(CDC)推荐的培养筛查策略评估孕妇孕晚期GBS的定植率;对1018对孕妇-新生儿配对病例进行垂直传播筛查,追踪新生儿结局,统计母婴垂直传播率及新生儿EOD的发病率。结果在培养筛查组,3487例孕妇标本中有142例GBS培养阳性,孕妇阴道GBS定植率为4.07%;在母婴垂直传播筛查组,1018对配对标本中,有52例孕妇GBS培养阳性,其分娩新生儿有4例阳性,垂直传播率为7.69%。在1062例纳入研究的新生儿中有1例发生EOD,其发病率为0.94%。(1/1062)。结论虽然孕妇孕晚期GBS定植率低,但其垂直传播率及新生儿EOD发病率均较高。有必要于有条件的地区进一步推行GBS产前筛查和相关治疗。

围产期孕妇与新生儿中B群链球菌(GBS)感染率及耐药性分析

目的研究围产期孕妇及其分娩新生儿GBS的感染率以及耐药性,从而探讨GBS的临床特点,为临床医师提供准确的用药依据。方法对408例围产期孕妇以及分娩后415例新生儿进行样本采集,之后给予GBS细菌鉴定及药敏试验,记录鉴定及药敏试验结果。结果 408例围产期孕妇GBS阳性检测率为21.1%,415例新生儿的GBS阳性检测率为3.1%,提示围产期孕妇及新生儿GBS检测阳性率较去年有所上升,新生儿早发型GBS感染有增加的趋势。分离菌株对头孢唑啉、左氧氟沙星和万古霉素均敏感,对青霉素和氨苄青霉素虽然没有耐药但其中介率达到6.8%。对克林霉素的耐药率和中介率分别为10.6%和16.5%。GBS耐药性有所增强。结论研究表明,及时的进行GBS预防检查,对GBS感染的孕妇与GBS早发型新生儿应及早进行治疗,并恰当的选择治疗药物,避免耐药性的增加,同时定期对新生儿进行GBS检查,避免晚发型GBS感染,提高围产期孕妇与新生儿生活质量。

孕妇妊娠晚期B族链球菌感染对妊娠结局及新生儿的影响

目的:分析孕妇妊娠晚期B族链球菌感染对妊娠结局及新生儿的影响。方法:2019年3月-2020年3月收治妊娠晚期B族链球菌感染孕妇100例,作为感染组;选取同期妊娠晚期无感染的孕妇100例,作为正常组。比较两组妊娠结局和新生儿结局。结果:感染组胎膜早破、宫内感染、产褥感染及剖宫产的发生率均高于正常组,且新生儿感染、新生儿窒息及新生儿肺炎的发生率均高于正常组,差异有统计学意义(P<0.05)。结论:妊娠晚期B族链球菌感染产妇的不良妊娠结局及新生儿疾病发病率均较高。

早产儿侵袭性B族链球菌感染疾病分布特点与血清分型研究

目的探讨对早产儿侵袭性B族链球菌感染疾病分布特点与血清分型,为早产儿侵袭性GBS感染的预防和治疗提供参考。方法选取2016年1月-2018年5月在医院诊治的侵袭性GBS感染早产儿60例,采集患儿痰液、血液分泌物等标本进行病原菌分离培养、菌株鉴定,采用乳胶凝集法对GBS血清分型进行检测。结果患儿诊断肺炎7例、败血症14例、化脓性脑膜炎6例、肺炎合并败血症13例、败血症合并化脓性脑膜炎7例、肺炎合并败血症及化脓性脑膜炎13例,分别占11.67%、23.33%、10.00%、21.67%、11.67%、21.67%;肺炎患儿主要以发热及气促为临床表现,败血症以发热为主要临床表现,化脓性脑膜炎主要以发热、呼吸困难、四肢肌张力高为临床表现;患儿检出的60株GBS血清型分别为Ia型6株、Ib型8株、III型37株、V型2株,分别占10.00%、13.33%、61.67%、3.33%,以III型为主;败血症、化脓性脑膜炎、肺炎合并败血症、败血症合并化脓性脑膜炎、肺炎合并败血症及化脓性脑膜炎均以III型为主,分别占57.14%、83.33%、69.23%、55.56%、69.23%;早发型和晚发型GBS均以III型为主,血清分型比较差异无统计学意义(P>0.05)。结论早产儿侵袭性B族链球菌感染疾病以败血症、肺炎合并败血症、化脓性脑膜炎等多种疾病合并多见,血清分型均以III型为主,血清分型与疾病临床感染分型无关。

B族链球菌规律成簇间隔短回文重复序列与基因分型及耐药基因的关系

目的:探讨孕晚期孕妇生殖道定植及侵袭性感染患儿的B族链球菌(group B Streptococcus,GBS)规律成簇间隔短回文重复序列(clustered regularly interspaced short palindromic repeats,CRISPR)分布及其与多位点序列分型(multilocus sequence typing,MLST)、耐药基因的关系。方法:回顾性收集2017年1月至2022年1月山西医科大学附属儿童医院(山西省妇幼保健院)收治的孕晚期孕妇定植GBS及GBS侵袭性感染患儿临床分离的84株GBS菌株(包括侵袭性菌株17株、定植菌株67株),检测其CRISPR、MLST、耐药表型及耐药基因。采用χ^(2)检验或Fisher精确概率法进行统计分析,并采用MEGA11构建发育树图。结果:84株中共有10种ST型别,最常见的是ST10(46.4%)。GBS对青霉素敏感,对红霉素和克林霉素的耐药率分别为75.0%和73.8%;17株GBS侵袭性菌株中,ST10型对红霉素、克林霉素以及左氧氟沙星耐药率达100%。62株检出CRISPR1基因,阳性率为73.8%;CRISPR1阳性菌株中ST10占比显著高于CRISPR1阴性菌株[56.5%(35/62)与18.2%(4/22),χ^(2)=9.56,P=0.002];CRISPR1阳性菌株中检出ermB、gyrA、parC比例明显高于阴性菌株[分别为54.8%(34/62)与22.7%(5/22)、67.7%(42/62)与36.4%(8/22)及71.0%(44/62)与36.4%(8/22),χ^(2)值分别为6.73、6.64及8.25,P值均<0.05],而ermA的比例低于阴性菌株[6.5%(4/62)与31.8%(7/22),χ^(2)=7.09,P=0.008]。结论:ST10是孕妇生殖道定植GBS及婴儿侵袭性GBS感染的主要基因型;GBS对青霉素敏感;在CRISPR1阳性菌株中ST10型GBS占优势;CRISPR1与部分耐药基因的传播相关。