{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,8]],"date-time":"2026-10-08T20:23:22Z","timestamp":1791491002697,"version":"4.3.4"},"reference-count":45,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,1,20]],"date-time":"2026-01-20T00:00:00Z","timestamp":1768867200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Cell. Infect. Microbiol."],"abstract":"\n Background<\/jats:title>\n \n Streptococcus agalactiae<\/jats:italic>\n increases the risk of adverse pregnancy outcomes and neonatal infections. Clindamycin is a key alternative for intrapartum prophylaxis in penicillin-allergic women, but the prevalence of clindamycin-resistant\n S. agalactiae<\/jats:italic>\n is increasing, posing a significant clinical challenge.\n <\/jats:p>\n <\/jats:sec>\n \n Methods<\/jats:title>\n A total of 178 strains isolated from tertiary hospitals in Jinan and Qingdao, Shandong Province, China, were characterized using antimicrobial susceptibility testing, whole-genome sequencing, multilocus sequence typing, serotyping, and analysis of resistance and virulence genes.<\/jats:p>\n <\/jats:sec>\n \n Results<\/jats:title>\n \n All strains were susceptible to penicillin, ampicillin, linezolid, vancomycin, and tigecycline. In contrast, resistance rates to erythromycin, levofloxacin, and tetracycline were 95.5%, 60.1%, and 56.7%, respectively. Six serotypes and 15 sequence types belonging to eight clonal complexes were identified. Notable regional differences were observed. The Ib-ST10-CC12 lineage dominated in Jinan, whereas V-ST529-CC327 was predominant in Qingdao. The resistance gene\n mreA<\/jats:italic>\n was ubiquitous (100%), followed by\n ermB<\/jats:italic>\n (80.3%). The key virulence genes\n cylE<\/jats:italic>\n ,\n hylB<\/jats:italic>\n , and\n pavA<\/jats:italic>\n , were detected in all strains.\n fbsA<\/jats:italic>\n (99.4%), the alpha protein family (98.9%),\n cfb<\/jats:italic>\n (98.3%), the Pilus Island gene cluster (94.9%), and\n lmb<\/jats:italic>\n (92.7%) were also highly prevalent. The two major clindamycin resistance genes,\n erm<\/jats:italic>\n and\n lnuB<\/jats:italic>\n , exhibited distinctly different enrichment patterns among\n S. agalactiae<\/jats:italic>\n clonal complexes, despite a certain overlap in CC19 and CC327. Specifically,\n erm<\/jats:italic>\n was significantly enriched in CC12 (serotype Ib), CC19 (III\/V), and CC327 (III\/V). In contrast,\n lnuB<\/jats:italic>\n was predominantly restricted to CC19 and CC327, where it defined a unique phylogenetic subcluster. Significant differences in resistance and virulence gene profiles were observed across different clonal complexes.\n <\/jats:p>\n <\/jats:sec>\n \n Conclusion<\/jats:title>\n \n Clindamycin-resistant\n S. agalactiae<\/jats:italic>\n in late-pregnancy women in Shandong Province, China exhibits a broad resistance spectrum, diverse molecular types, and significant regional heterogeneity. These findings underscore the need for continued surveillance and region-specific strategies for preventing neonatal\n S. agalactiae<\/jats:italic>\n infections.\n <\/jats:p>\n <\/jats:sec>","DOI":"10.3389\/fcimb.2025.1721174","type":"journal-article","created":{"date-parts":[[2026,1,20]],"date-time":"2026-01-20T06:33:16Z","timestamp":1768890796000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":2,"title":["Drug-resistant genes, virulence characteristics, and molecular typing of clindamycin-resistant Streptococcus agalactiae in late pregnancy"],"prefix":"10.3389","volume":"15","author":[{"given":"Meng","family":"Yu","sequence":"first","affiliation":[{"name":"Clinical Laboratory, Qingdao Municipal Hospital","place":["Qingdao, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ting","family":"Yu","sequence":"additional","affiliation":[{"name":"Clinical Laboratory, Qingdao Municipal Hospital","place":["Qingdao, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shui","family":"Yu","sequence":"additional","affiliation":[{"name":"Clinical Laboratory, Qingdao Women and Children\u2019s Hospital","place":["Qingdao, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Li","family":"Li","sequence":"additional","affiliation":[{"name":"Clinical Laboratory, Qingdao Municipal Hospital","place":["Qingdao, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shuang","family":"Chen","sequence":"additional","affiliation":[{"name":"Clinical Laboratory, Qingdao Municipal Hospital","place":["Qingdao, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yujie","family":"Wang","sequence":"additional","affiliation":[{"name":"Clinical Laboratory, Qingdao Municipal Hospital","place":["Qingdao, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kun","family":"Wang","sequence":"additional","affiliation":[{"name":"Clinical Laboratory, Jinan Maternity and Child Care Hospital Affiliated to Shandong First Medical University","place":["Jinan, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,1,20]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","first-page":"263","DOI":"10.1016\/s1473-3099(20)30478-3","article-title":"Safety and immunogenicity of a novel hexavalent group B streptococcus conjugate vaccine in healthy, non-pregnant adults: a phase 1\/2, randomised, placebo-controlled, observer-blinded, dose-escalation trial","volume":"21","author":"Absalon","year":"2021","journal-title":"Lancet Infect. 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