内科

目的分析孕晚期女性无乳链球菌（S. agalactiae）定植与小婴儿感染及耐药情况。方法对2017～2023年在广西壮族自治区妇幼保健院建卡的137 790例孕晚期女性进行S. agalactiae筛查（其中有24 723例在该院分娩），并回顾性分析同期该院住院的48 927例0～3月龄婴儿的临床资料，以了解孕晚期女性S. agalactiae定植与小婴儿的S. agalactiae感染情况。对在该院分娩的S. agalactiae阳性孕妇及同期住院的S. agalactiae感染小婴儿分离菌株进行药物敏感性试验。结果 137 790例孕晚期女性中，S. agalactiae阳性检出率为12.56%（17 303/137 790），肛拭子的检出率（9.81%，13 519/137 790）高于阴道拭子（7.88%，10 862/137 790）（P<0.05）。24 723例该院分娩的孕妇中，检出S. agalactiae阳性452例，共分离出523株S. agalactiae；同期48 927例住院小婴儿中，43例确诊S. agalactiae感染（0.09%），共分离出54株S. agalactiae。S. agalactiae孕妇株和婴儿株对四环素（85.47%，83.33%）、红霉素（69.22%，75.93%）和克林霉素（50.09%，72.22%）的耐药率较高，对左氧氟沙星的耐药率相对较低（17.78%，3.70%），而对青霉素等其他抗菌药物均敏感。43例S. agalactiae感染患儿的主要临床表现包括肺炎、呼吸窘迫综合征、休克、败血症和高胆红素血症，其病死率为23.26%，其中早发型感染（29.63%，8/27）与晚发型感染（12.50%，2/16）的病死率差异无统计学意义（P>0.05）。结论孕晚期女性S. agalactiae检出率较高，采用肛拭子联合阴道拭子检测可提高S. agalactiae检出率。孕妇株和婴儿株对四环素、红霉素和克林霉素均呈现高耐药性，但对首选预防用药青霉素仍保持敏感。孕晚期S. agalactiae定植可能增加小婴儿不良结局风险，建议通过规范筛查和产时抗生素预防降低母婴传播概率。

Objective To analyze the colonization status of Streptococcus agalactiae (S. agalactiae) in women during late-pregnancy and the infection status in infants, as well as the drug resistance of S. agalactiae. Methods This study screened 137 790 late-pregnancy women registered at Maternity and Child Health Care of Guangxi Zhuang Autonomous Region from 2017 to 2023 (including 24 723 who delivered at this institution), with concurrent retrospective analysis of clinical data from 48 927 hospitalized infants aged 0-3 months, to characterize both maternal S. agalactiae colonization patterns in late pregnancy and S. agalactiae infection profiles in young infants. Drug susceptibility tests were performed on the strains isolated from S. agalactiae-positive pregnant women who delivered in this hospital and S. agalactiae-infected infants hospitalized during the same period. Results Among the 137 790 women during late-pregnancy, the positive detection rate of S. agalactiae was 12.56% (17 303/137 790), and the detection rate of anal swabs (9.81%, 13 519/137 790) was higher than that of vaginal swabs (7.88%, 10 862/137 790) (P<0.05). Among the 24 723 pregnant women who delivered in that hospital, 452 were detected as S. agalactiae-positive, and a total of 523 strains of S. agalactiae were isolated. Among the 48 927 infants hospitalized during the same period, 43 were diagnosed with S. agalactiae infection (0.088%), and a total of 54 strains of S. agalactiae were isolated. Both pregnant women and infant strains of S. agalactiae showed high resistance rates to tetracycline (85.47%, 83.33%), erythromycin (69.22%, 75.93%), and clindamycin (50.09%, 72.22%), but the resistance rates to levofloxacin were relatively low (17.78%, 3.70%), while they were sensitive to penicillin and other antibacterial drugs. The main clinical manifestations of the 43 children with S. agalactiae infection included pneumonia, respiratory distress syndrome, shock, sepsis, and hyperbilirubinemia. Their mortality rate was 23.26%, and there was no statistically significant difference in the mortality rate between early-onset infections (29.63%, 8/27) and late-onset infections (12.50%, 2/16) (P>0.05). Conclusion The detection rate of S. agalactiae in women during late-pregnancy is relatively high, and the combined detection using anal swabs and vaginal swabs can improve the detection rate of S. agalactiae. Both pregnant women and infant strains show high resistance to tetracycline, erythromycin, and clindamycin, but remain sensitive to penicillin, the first-choice prophylactic agent. Given that colonization of S. agalactiae in late pregnancy may increase the risk of adverse outcomes in infants, standardized screening and intrapartum antibiotic prophylaxis are recommended to reduce the probability of mother-to-child transmission.