晚期妊娠孕妇B群链球菌定植状况及妊娠结局分析

目的: 探讨妊娠晚期孕妇B群链球菌（GBS）定植情况、抗菌药物敏感性及妊娠结局。方法: 纳入2016年1月至2018年12月在东部战区总医院和南京医科大学第一附属医院妇产科定期产检的孕妇，于孕35~37周采用标准方法采集阴道及直肠拭子进行GBS培养，并对阳性标本分离的菌株进行药物敏感性试验。按培养结果分为GBS阳性组和GBS阴性组，阳性组按照产程中是否使用了抗菌药物治疗分为用药组与未用药组，比较不同组别妊娠结局的差异。结果: 共13 000名孕妇入组，GBS总体定植率为3.65%（475/13 000）。GBS在阴道中定植率为2.33%（303/13 000），在直肠中定植率为1.75%（227/13 000）。通过对直肠标本的采集检测，GBS阳性检出率增加了56.77%（172/303）。GBS每月的定植率有明显波动，3月份和10月份最高（均P < 0.05）。475份GBS阳性标本对头孢曲松、万古霉素和利奈唑胺的敏感率为100%，对氨苄西林和青霉素的敏感率分别为97.26%和93.47%，而对左氧氟沙星、克林霉素、红霉素、四环素的耐药率较高，分别为30.11%、48.00%、52.21%和88.63%。GBS阳性组胎膜早破、产后出血、产褥期感染、新生儿肺炎、败血症发生率较GBS阴性组明显增高（均P < 0.01）。产程中预防性使用抗菌药物的GBS阳性孕妇产褥期感染、新生儿感染及新生儿重症监护室入住率明显低于未使用抗菌药物的孕妇（P < 0.05或P < 0.01）。结论: 妊娠晚期孕妇GBS定植率较低，无明显的季节性，通过补充直肠检测能提高GBS检出率。头孢曲松、氨苄西林和青霉素是目前预防和治疗GBS相关疾病的首选药物。GBS感染会明显增加母婴并发症的发生可能，产程中抗菌药物治疗可以改善母婴的结局。

Relationship of group B streptococcus colonization in late pregnancy with perinatal outcomes

Objective: To investigate the relationship of group B streptococcus (GBS) colonization in late pregnancy with perinatal outcome. Methods: Pregnant women who underwent antenatal check-up at General Hospital of PLA Eastern Theater Command and the First Affiliated Hospital of Nanjing Medical University from January 2016 to December 2018 were enrolled in the study. The vaginal and rectal swab samples were collected for GBS culture at 35-37 weeks of pregnancy. The perinatal outcomes of positive and negative GBS groups were compared. The GBS-positive group samples were tested for antibiotic susceptibility. In GBS positive group the maternal and child perinatal outcomes were compared between pregnant women with antibiotics treatment and those without antibiotics. Results: A total of 13 000 pregnant women were enrolled, and the overall colonization rate of GBS was 3.65%(475/13 000). The colonization rate of GBS in the vagina was 2.33%(303/13 000), and the colonization rate in the rectum was 1.75%(227/13 000). Through the collection and detection of rectal specimens, the positive rate of GBS increased by 56.77%(172/303). The monthly colonization rate of GBS showed significant fluctuations with the highest in March and October (all P < 0.05). The sensitivity of 475 GBS-positive specimens to ceftriaxone, vancomycin and linezolid were 100%, and the sensitivity to ampicillin and penicillin were 97.26%and 93.47%, respectively. The resistance rates of the strains to levofloxacin, clindamycin, erythromycin and tetracycline were 30.11%, 48.00%, 52.21%and 88.63%. The incidence of premature rupture of membranes, postpartum hemorrhage, puerperal infection, neonatal pneumonia and sepsis in GBS positive group were significantly higher than those in GBS negative group (all P < 0.01). In pregnant women with positive GBS, the incidence of puerperal infection, neonatal infection and admission to the NICU in the antibiotic group were significantly lower than those in the non-antibiotic group (P < 0.05 or P < 0.01). Conclusions: The total colonization rate of GBS is low. The detection of GBS can be significantly improved by supplementing rectal examination. Ceftriaxone, ampicillin and penicillin are currently the drugs of choice for the prevention and treatment of GBS-related diseases. GBS infection can increase the incidence of maternal and child complications. The use of antibiotics during labor can improve the outcome of mothers and infants.