Microb Genom. 2026 Jul;12(7). doi: 10.1099/mgen.0.001798.
ABSTRACT
Staphylococcus capitis is a common pathogen causing late-onset sepsis in neonatal intensive care units (NICUs). A specific clone, S. capitis NRCS-A, which was first reported in 2012 from France, is spreading globally in NICU settings. The present study was carried out to explore the molecular characteristics and clinical features of S. capitis bacteraemia among infants hospitalized in NICUs in Taiwan. We retrieved and molecularly characterized 191 S. capitis bloodstream isolates from hospitalized patients of a medical centre in Taiwan between 2014 and 2021, with whole-genome sequencing (WGS) for 79 isolates. Seventy-three isolates were identified from 65 infants in neonatal units and 118 isolates from inpatients staying outside the neonatal units (non-neonates). Seventy-one (97%) of the 73 neonate isolates were characterized to 2 major pulsotypes: 16 out of 73 (22%) were pulsotype 300 which was similar to that of the NRCS-A strain, and 55 isolates were pulsotype 1300, while 27 pulsotypes were identified from 118 non-neonatal isolates. Seventy (96%) of 73 neonatal isolates were oxacillin-resistant. Of the 73 neonatal isolates and 6 selective non-neonatal isolates (pulsotype 300 for 5 isolates) selected for WGS, 69 neonatal isolates and 5 non-neonatal isolates clustered into four major clades (A to D), corresponding to the two major pulsotypes, 300 and 1300. By phylogenetic analysis, 15 neonatal isolates and 5 non-neonatal isolates, sharing pulsotype 300 and clades C/D, were embedded within the international isolates of the previously designated pandemic outbreak clone of the NRCS-A strain and also carried NRCS-A strain-related marker genes, confirmed as the NRCS-A strain. In addition to resistance to oxacillin and penicillin, the dominant clone (non-NRCS-A strain) exhibited additional resistance to erythromycin and clindamycin. Conclusively, in contrast to diverse genetic characteristics among non-neonatal isolates, over 95% of S. capitis bloodstream isolates from neonates in Taiwanese NICUs were resistant to oxacillin and belonged to two major clones, including the NRCS-A strain. The dominant clone was a non-NRCS-A strain and exhibited broader antibiotic resistance. Further surveillance is needed.
PMID:42525550 | DOI:10.1099/mgen.0.001798