From the Division of Infectious Diseases, Departments of Pediatrics, College of Medicine, The Catholic University of Korea, Seoul, Korea.
Clinical Research Institute, Daejeon St. Mary's Hospital, The Catholic University of Korea, Daejeon, Korea.
Pediatr Infect Dis J. 2021 Jan;40(1):49-54. doi: 10.1097/INF.0000000000002882.
To investigate the genetic characteristics associated with eradication failure of Staphylococcus aureus in infants below 90 days old.
S. aureus isolated from clinical specimen cultures (blood, surgical tissue, or drainage, pus, etc.) and routine screening cultures in the neonatal intensive care unit (nasal and axillary skin swab) from patients below 90 days old were collected prospectively for 1 year, from August 2017 to July 2018. The isolates underwent typing and screening for genes associated with chlorhexidine (qacA/B), quaternary ammonium (smr), and mupirocin resistance (iles mutation, mupA, mupB), as well as Panton-Valentine leukocidin (PVL) toxin.
During the study period, 40 nonduplicate isolates were included for analyses, of which 70.0% were methicillin-resistant S. aureus (MRSA). Mupirocin resistance was found in 25% of the total isolates; 17.4% of the colonizers; and 35.3% of the pathogens (P = 0.196). Chlorhexidine resistance gene was found in 3 MRSA isolates colonized in the nares of preterm infants. All isolates harbored the disinfectant quaternary ammonium compound (QAC) resistance gene. PVL toxin gene was found in 57.5%, and the presence of PVL gene among colonizers and pathogens was similar (69.6% vs. 41.2%, P = 0.072).
Mupirocin, chlorhexidine, and QAC-resistant MRSAs harboring the PVL toxin gene were found in the nasal carriages of preterm infants. In this highly vulnerable patient population, one-fourth of the isolates harbored mupirocin-resistant genes, and all were resistant to QAC disinfectants. These strains are associated with persistence in both carriage and environmental reservoirs within the hospitals.
研究与 90 天以下婴儿金黄色葡萄球菌根除失败相关的遗传特征。
前瞻性收集 2017 年 8 月至 2018 年 7 月 1 年间，年龄在 90 天以下、来自新生儿重症监护病房（鼻和腋窝皮肤拭子）的临床标本培养（血液、手术组织或引流液、脓液等）和常规筛查培养中分离的金黄色葡萄球菌。对分离株进行基因分型和与洗必泰（qacA/B）、季铵盐（smr）和莫匹罗星耐药（ileS 突变、mupA、mupB）以及杀白细胞素（PVL）毒素相关基因的筛选。
研究期间共纳入 40 例非重复分离株进行分析，其中 70.0%为耐甲氧西林金黄色葡萄球菌（MRSA）。莫匹罗星耐药在总分离株中发现 25.0%，定植者中发现 17.4%，病原体中发现 35.3%（P=0.196）。3 例耐甲氧西林金黄色葡萄球菌定植于早产儿鼻腔，发现莫匹罗星耐药基因。所有分离株均携带消毒剂季铵化合物（QAC）耐药基因。PVL 毒素基因在 57.5%中发现，定植者和病原体中存在 PVL 基因相似（69.6%比 41.2%，P=0.072）。
在早产儿鼻腔定植中发现了携带 PVL 毒素基因的莫匹罗星、洗必泰和 QAC 耐药的耐甲氧西林金黄色葡萄球菌。在这个高度脆弱的患者群体中，四分之一的分离株携带莫匹罗星耐药基因，且所有分离株均对 QAC 消毒剂耐药。这些菌株与医院内定植和环境储库中的持续存在有关。
