Occurrence and Characteristics of Mcrs among Gram-Negative Bacteria Causing Bloodstream Infections of Infant Inpatients between 2006 and 2019 in China

Wu，Lijuan1,4; Xu，Tingting2,3; Ji，Yang2,3; Song，Jingjie2,3; Wang，Feiling1; Huang，Junxi2,3; Zhou，Kai2,3

2022-02-01

10.1128/spectrum.01938-21

Microbiology Spectrum   影响因子和分区

2165-0497

2165-0497

The aim of this study was to determine the occurrence of mobilized colistin resistance (mcr) genes in Gram-negative bacteria causing bloodstream infections of child inpatients in China. Bacteria were collected between 2006 and 2019 in a maternal and child health hospital, and mcr genes were screened by PCR. Five of 252 isolates were mcr-positive, including one mcr-1-positive colistin-resistant Escherichia coli isolate, two mcr-9-positive colistin-susceptible Salmonella enterica isolates, and two mcr-9-positive colistin- susceptible Enterobacter hormaechei isolates. These were obtained from two neonate and three infant patients admitted between 2009 and 2018. The E. coli isolate was obtained from a neonate aged 20 min, suggestive of a possible mother-to-neonate transmission. The five mcr-positive isolates were multidrug resistant, and two S. enterica and one E. hormaechei isolate showed a hypervirulent phenotype compared to a hypervirulent Klebsiella pneumoniae type strain in a Galleria mellonella infection model. The mcr-1 gene was carried by an IncX4-type pA1-like epidemic plasmid, and the mcr-9 gene was detected on IncHI2/2A-type novel plasmids co-carrying multiple resistance genes. The four IncHI2/2A-type plasmids shared a backbone and a high similarity ($77% coverage and $ 90% nucleotide identity), suggesting that they were derived from a common ancestor with cross-species transmission and have circulated locally over a long period. The conjugation assay showed that the mcr-1-encoding plasmid and one mcr-9-encoding plasmid were self-transmissible to E. coli with high conjugation frequencies. Our findings demonstrate that mcr genes have disseminated in the community and/or hospitals, mediated by epidemic/endemic plasmids over a long period. The study shows that continuous monitoring of mcr genes is imperative for understanding and tackling their dissemination.

Bloodstream infections Infant Mcr-1 Mcr-9

SCI

英语

通讯

National Key R&D Program of China[2021YFC2300300] ; National Natural Science Foundation of China[81902030,81902121,82172330] ; Shenzhen Basic Research Key projects[JCYJ20200109144220704] ; Shenzhen Key Medical Discipline Construction Fund[SZXK028] ; Shenzhen Basic Research projects["JCYJ20180228163744684","JCYJ20190807144409307"]

Microbiology

Microbiology

WOS:000766015800151

AMER SOC MICROBIOLOGY

2-s2.0-85124265928

Scopus

1.Clinical Laboratory,Shenzhen Bao'an Women and Children's Hospital,Shenzhen,Guangdong,China
2.Shenzhen Institute of Respiratory Diseases,Second Clinical Medical College (Shenzhen People's Hospital),Jinan University,Shenzhen,Guangdong,China
3.The First Affiliated Hospital (Shenzhen People's Hospital),Southern University of Science and Technology,Shenzhen,Guangdong,China
4.Maternal-Fetal Medicine Institute,Shenzhen Bao'an Women and Children's Hospital,Shenzhen,Guangdong,China

Wu，Lijuan,Xu，Tingting,Ji，Yang,et al. Occurrence and Characteristics of Mcrs among Gram-Negative Bacteria Causing Bloodstream Infections of Infant Inpatients between 2006 and 2019 in China[J]. Microbiology Spectrum,2022,10(1).

Wu，Lijuan.,Xu，Tingting.,Ji，Yang.,Song，Jingjie.,Wang，Feiling.,...&Zhou，Kai.(2022).Occurrence and Characteristics of Mcrs among Gram-Negative Bacteria Causing Bloodstream Infections of Infant Inpatients between 2006 and 2019 in China.Microbiology Spectrum,10(1).

Wu，Lijuan,et al."Occurrence and Characteristics of Mcrs among Gram-Negative Bacteria Causing Bloodstream Infections of Infant Inpatients between 2006 and 2019 in China".Microbiology Spectrum 10.1(2022).