中国循证儿科杂志 ›› 2021, Vol. 16 ›› Issue (5): 379-383.

• 论著 • 上一篇    下一篇

住院新生儿鼻腔和体表定植金黄色葡萄球菌的分子特征及耐药性

王红1,王博1,耿文静1,向希盈1,王青2,3,姚开虎2,3,黑明燕1,3   

  1. 国家儿童医学中心,首都医科大学附属北京儿童医院北京,100045;1 新生儿中心,2 北京市儿科研究所,3 教育部儿科重大疾病研究重点实验室
  • 收稿日期:2021-10-25 修回日期:2021-10-25 出版日期:2021-10-25 发布日期:2021-10-25
  • 通讯作者: 黑明燕
  • 作者简介:黑明燕

Molecular characteristics and antibiotic resistance of colonized Staphylococcus aureus at mucosal and skin surface in hospitalized neonates

WANG Hong1, YU Jie1, WANG Bo1, GENG Wenjing1, XIANG Xiying1, WANG qing2, 3, YAO Kaihu2, 3, HEI Mingyan1, 3   

  • Received:2021-10-25 Revised:2021-10-25 Online:2021-10-25 Published:2021-10-25
  • About author:HEI Mingyan

摘要: 背景:金黄色葡萄球菌(SA)在鼻腔和体表的定植可增加新生儿SA感染的风险,了解住院新生儿的SA定植状况、菌株分子型及耐药性有助于制定合理的治疗方案。 目的:探讨NICU患儿入院时体表的SA定植、菌株分子特征及耐药性。 设计:横断面研究。 方法:纳入2020年8月1日至2021年1月31日入住首都医科大学附属北京儿童医院NICU时入院日龄≤28 d且胎龄≥28周的新生儿,收集临床信息。并对入院后12 h 内体表部位采集的拭子进行细菌培养和菌落计数,采用Staphytect Plus试剂盒及PCR扩增nuc基因进行SA菌株鉴定,并分别进行抗生素耐药性检测。 主要结局指标:NICU住院新生儿体表定植的SA分子特征及耐药性。 结果:共纳入766例NICU住院新生儿,其中257例(33.6%)存在≥1个部位的SA定植,单部位、2个部位、≥3个部位SA定植组分别为135例(52.5%)、65例(25.2%)和57例(22.3%),各组间的临床特征(男婴、入院日龄、剖宫产、入院前纯母乳喂养、入院前应用抗生素、入院时气管插管常频机械通气、住院天数)、菌株分型(MRSA、MSSA)、sarA基因状态差异均无统计学意义,PVL 阳性差异有统计学意义。≥2个部位定植组与1个部位定植组比较,PVL阳性 [39(32.0%)vs 23(17.0%) ,P=0.005]和sarA 阳性[83(68.0%) vs 56 (41.5%),P<0.01]差异有统计学意义。鼻前庭、脐根部、腋下和腹股沟分别培养出176株、124株、72株和76株,MSSA占比分别为82.4%、77.4%、80.6%和80.3%,各部位SA菌株的MRSA和MSSA占比差异均无统计学意义。MSSA菌株最常见的克隆型为ST398- t309型,MRSA菌株最常见的克隆型为ST59-SCCmecIV-t437。PVL 、sarA和PVL+sarA基因检测阳性株,MRSA和MSSA阳性率差异均无统计学意义。所有的288株SA均对莫匹罗星、利奈唑胺及万古霉素敏感;15株美罗培南不敏感株,其中MRSA 14株(1株耐药,13株中介),MSSA 1株(中介);耐药率从高到低依次为青霉素、红霉素、头孢曲松和苯唑西林。 结论:NICU相对病情稳定的新生儿鼻腔和体表皮肤SA定植率为33.6%。≥2个部位定植与1个部位定植相比,PVL和sarA阳性更高。MSSA菌株最常见的克隆型为ST398-t309,MRSA菌株最常见的克隆型为ST59-SCCmecIV-t437。本次研究中所有定植的SA菌株均对莫匹罗星、利奈唑胺及万古霉素敏感,有对美罗培南耐药MRSA分子型菌株检出。

关键词: 金黄色葡萄球菌, 定植, 新生儿, 婴儿, 分子型, 耐药性

Abstract: Background:The colonization of Staphylococcus aureus (SA) on the mucosal and skin surface may increase the risk of SA infection in neonates. To understand the SA colonizing, molecular characteristics and drug resistance of SA strain in hospitalized neonates will facilitate the development of rational therapeutic strategies. Objective:To explore the colonization, molecular characteristics and drug resistance of SA isolates from neonates hospitalized in the neonatal intensive care unit (NICU). Design:A cross-sectional study. Methods:Neonates with age on admission ≤ 28 d and gestational age ≥28 week admitted to the NICU of Beijing Children's Hospital between August 1st, 2020 and January 31st, 2021 were enrolled. Clinical data were collected. The swab samples of the nasal cavity, axilla, root of the umbilicus and groin were collected for culture within the first 12 h after admission.The SA strain identification was completed by using a Staphytect Plus kit and the PCR amplification of nuc gene. Drug resistance of each colonized SA strain to antibiotics was tested. Main outcome measures:Molecular characteristics and drug resistance of the colonized SA at mucosal and skin surface of NICU hospitalized neonates. Result:sA total of 766 children were included, of which 257 (33.6%) had SA colonization at one or more sites. There were 135 (52.5%), 65 (25.2%),and 57 (22.3%) children who had 1, 2, and ≥ 3 sites colonization, respectively. Among them, the clinical characteristics (male, admission age, C-section rate, exclusive breast-feeding rate before admission, antibiotics exposure before admission, ventilation support on admission, and total hospital stay in days), categorization of methicillin-sensitive Staphylococcus aureus (MSSA) or methicillin-resistant Staphylococcus aureus (MRSA), sarA gene expression were not significantly different (all P>0.05). There was significant difference in PVL positive rates. To compare 1 site colonization with 2 sites colonization, the positive rates of both PVL [23 (17.0%) vs. 39(32.0%), P=0.005] and sarA [56 (41.5%) vs. 83(68.0%),P<0.01]were significantly different. There were 176, 124, 72, and 76 SA strains isolated from nasal mucosal cavity, root of umbilicus, axillary cavity, and groin region, with MSSA being the dominant categorization (82.4%, 77.4%, 80.6%, and 80.3%), respectively. There was no significant difference between MRSA and MSSA categorizations at each site (all P >0.05). The commonest MSSA clone was ST398-t309, and the commonest MRSA clone was ST59-SCCmecIV-t437. Among strains with PVL , sarA , and PVL + sarA positive expression, there was no significant difference between MRSA and MSSA categorizations. All strains were sensitive to Mupirocin, Linezolide, and Vancomycin. Totally 15 SA strains were insensitive to Meropenem, among which 14 were MRSA (1 was drug-resistant, 13 was medium sensitive) and 1 was MSSA (medium sensitive). The incidence of resistance to other antibiotics was 78.1% for Penicillin, 55.1% for Erythromycin, 19.8% for Ceftriaxone and 15.3% for Oxacillin, respectively. Conclusion:The SA colonization rate is 33.6% in relatively stable neonates in NICU. The positive rate of PVL 和 sarA in patients with SA colonization at ≥2 sites was higher than that at 1 site. The commonest MSSA clone was ST398-t309, and the commonest MRSA clone was ST59-SCCmecIV-t43. All strains were sensitive to Mupirocin, Linezolide, and Vancomycin. There were MRSA strains insensitive to Meropenem.

Key words: Staphylococcus aureus, Colonization, Newborn, Infant, Molecular characteristics, Antibiotics resistance