Department of Pathogen, Infection and Immunity, Nara Medical University, Kashihara, Nara, Japan.
Center for Infectious Diseases, Nara Medical University, Kashihara, Nara, Japan.
PLoS One. 2020 Oct 19;15(10):e0240590. doi: 10.1371/journal.pone.0240590. eCollection 2020.
Invasive Streptococcus agalactiae (GBS) infections are increasingly common among neonates and the elderly. Therefore, GBS surveillance for better antibiotic treatment and prophylaxis strategies are needed. We retrospectively evaluated the clinical aspects of invasive infections and the phenotypic and genetic diversity of infectious isolates from Nara, Japan, collected between 2007 and 2016, by using information from hospital records. GBS strains collected from the blood and cerebrospinal fluid cultures were evaluated for capsular types, multi-locus sequence typing (MLST), antibiotic susceptibility, antibiotics resistance gene, and pulsed-field gel electrophoresis. Forty GBS isolates (10 from children and 30 from adults) were analyzed, and the distribution of molecular serotype and allelic profiles varied between children and adults. We found the rates of early-onset disease in neonates with birth complications to be higher than that of previous reports, indicating that there could be relevance between complications at birth and early-onset disease. Standard antibiotic prophylaxis strategies may need to be reconsidered in patients with birth complications. In adults, the mean age of the patients was 68 years (male: 63%). Primary bacteremia was the most common source of infection. In the neonates, six had early-onset diseases and four had late-onset diseases. The most frequently identified strains were molecular serotype Ia ST23 (40%) and molecular serotype Ib ST10 (20%) in children and molecular serotype Ib ST10 (17%), molecular serotype VI ST1 (13%), and molecular serotype V ST1 (13%) in adults. Levofloxacin-resistant molecular serotype Ib strains and molecular serotypes V and VI ST1 were common causes of GBS infection in adults but were rarely found in children. Furthermore, pulsed-field gel electrophoresis in our study showed that specific clone isolates, that tend to have antibiotics resistance were widespread horizontally for a decade. Continuous surveillance and molecular investigation are warranted to identify the transmission route and improve antibiotic treatment strategies.
侵袭性无乳链球菌（GBS）感染在新生儿和老年人中越来越常见。因此，需要对 GBS 进行监测，以制定更好的抗生素治疗和预防策略。我们回顾性地评估了 2007 年至 2016 年间日本奈良收集的侵袭性感染的临床特征，以及感染分离株的表型和遗传多样性，使用的信息来自医院记录。对从血液和脑脊液培养物中收集的 GBS 菌株进行了荚膜型、多位点序列分型（MLST）、抗生素敏感性、抗生素耐药基因和脉冲场凝胶电泳分析。对 40 株 GBS 分离株（儿童 10 株，成人 30 株）进行了分析，儿童和成人的分子血清型和等位基因谱分布不同。我们发现，有出生并发症的新生儿早发性疾病的发生率高于以往的报告，这表明出生并发症与早发性疾病之间可能存在相关性。对于有出生并发症的患者，可能需要重新考虑标准的抗生素预防策略。在成人中，患者的平均年龄为 68 岁（男性：63%）。原发性菌血症是最常见的感染源。在新生儿中，有 6 例早发性疾病，4 例晚发性疾病。最常见的分离株是儿童中分子血清型 Ia ST23（40%）和分子血清型 Ib ST10（20%），以及成人中分子血清型 Ib ST10（17%）、分子血清型 VI ST1（13%）和分子血清型 V ST1（13%）。左氧氟沙星耐药的分子血清型 Ib 菌株和分子血清型 V 和 VI ST1 是成人 GBS 感染的常见原因，但在儿童中很少发现。此外，我们的研究中的脉冲场凝胶电泳显示，具有抗生素耐药性的特定克隆分离株在十年间广泛横向传播。需要持续监测和分子研究，以确定传播途径并改善抗生素治疗策略。
