中国南方儿童携带 mcr-1 基因的大肠杆菌的粪便携带情况和分子流行病学研究。

Fecal carriage and molecular epidemiology of mcr-1-harboring Escherichia coli from children in southern China.

机构信息

Clinical Laboratory, Longgang Maternity and Child Institute of Shantou University Medical College, Longgang District Maternity & Child Healthcare Hospital of Shenzhen City, Shenzhen 518172, PR China; Clinical Laboratory, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, Guangdong 510623, PR China; Clinical Laboratory, Affiliated Foshan Maternity & Child Healthcare Hospital, Southern Medical University, Foshan 528000, PR China.

Clinical Laboratory, Longgang Maternity and Child Institute of Shantou University Medical College, Longgang District Maternity & Child Healthcare Hospital of Shenzhen City, Shenzhen 518172, PR China; Clinical Laboratory, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, Guangdong 510623, PR China; Clinical Laboratory, Guangdong Provincial Second Hospital of Traditional Chinese Medicine, Guangdong Provincial Engineering Technology Research Institute of Traditional Chinese Medicine, Guangzhou 510095, PR China.

出版信息

J Infect Public Health. 2023 Jul;16(7):1057-1063. doi: 10.1016/j.jiph.2023.05.005. Epub 2023 May 11.

DOI:10.1016/j.jiph.2023.05.005

PMID:37196369

Abstract

BACKGROUND

The increase of multidrug-resistant Enterobacteriaceae bacteria has led to the reintroduction of colistin for clinical treatments, and colistin has become a last resort for infections caused by multidrug-resistant bacteria. Enterobacteriaceae bacteria carrying the mcr-1 gene are majorly related to colistin resistance, which may be the main reason for the continued increase in the colistin resistance rate of Enterobacteriaceae. The study aimed to investigate the sequence type and prevalence of Escherichia coli (E. coli) harboring the mcr-1 gene in the gut flora of children in southern China.

METHODS

Fecal samples (n = 2632) of children from three medical centers in Guangzhou were cultured for E. coli. The mcr-1-harboring isolates were screened via polymerase chain reaction (PCR). The colistin resistance transfer frequency was studied by conjugation experiments. DNA sequencing data of seven housekeeping genes were used for multi-locus sequence typing analysis (MLST).

RESULTS

PCR indicated that 21 of the 2632 E. coli (0.80%) isolates were positive for mcr-1; these strains were resistant to colistin. Conjugation experiments indicated that 18 mcr-1-harboring isolates could transfer colistin resistance phenotypes to E. coli J53. MLST analysis revealed that the 21 isolates were divided into 18 sequence types (STs); E. coli ST69 was the most common (14.3%), followed by E. coli ST58 (9.5%).

CONCLUSION

These results demonstrate the colonization dynamics and molecular epidemiology of E. coli harboring mcr-1 in the gut flora of children in southern China. The mcr-1 gene can be horizontally transmitted within species; hence, it is necessary to monitor bacteria that harbor mcr-1 in children.

摘要

背景

多药耐药肠杆菌科细菌的增加导致粘菌素重新用于临床治疗，而粘菌素已成为治疗多药耐药菌感染的最后手段。携带 mcr-1 基因的肠杆菌科细菌主要与粘菌素耐药性有关，这可能是肠杆菌科粘菌素耐药率持续上升的主要原因。本研究旨在调查中国南方儿童肠道菌群中携带 mcr-1 基因的大肠杆菌（E. coli）的序列型和流行率。

方法

对来自广州三家医疗中心的 2632 名儿童的粪便样本进行大肠杆菌培养。通过聚合酶链反应（PCR）筛选携带 mcr-1 的分离株。通过接合实验研究粘菌素耐药转移频率。对 7 个管家基因的 DNA 测序数据进行多位点序列分型分析（MLST）。

结果

PCR 表明，2632 株大肠杆菌中有 21 株（0.80%）mcr-1 阳性；这些菌株对粘菌素耐药。接合实验表明，18 株 mcr-1 携带株可将粘菌素耐药表型转移至大肠杆菌 J53。MLST 分析显示，21 株分离株分为 18 种序列型（ST）；大肠杆菌 ST69 最为常见（14.3%），其次是大肠杆菌 ST58（9.5%）。