1. The Microbiological Characteristics of Carbapenem-Resistant Enterobacteriaceae Carrying the mcr-1 Gene.
- Author
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Chen, Chih-Wei, Tang, Hung-Jen, Chen, Chi-Chung, Lu, Ying-Chen, Chen, Hung-Jui, Su, Bo-An, Weng, Tzu-Chieh, Chuang, Yin-Ching, and Lai, Chih-Cheng
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PULSED-field gel electrophoresis ,ENTEROBACTERIACEAE ,NOSOCOMIAL infections ,GENES ,MEMBRANE proteins - Abstract
Objectives: This study aims to assess the prevalence of the mcr-1 gene among carbapenem-resistant Enterobacteriaceae (CRE) isolated from clinical specimens and to further investigate the clinical significance and microbiological characteristics of CRE carrying the mcr-1 gene. Methods: Four hundred and twenty-three CRE isolates were screened for the presence of the mcr-1 gene. After identification, their clinical significance, antibiotic susceptibility, and antibiotic resistance mechanisms including the ESBL gene, carbapenemase gene, outer membrane protein (OMP), and plasmid sequencing were assessed. Results: Only four (0.9%) isolates of carbapenem-resistant Escherichia coli (E. coli) were found to carry the mcr-1 gene and demonstrated different pulsed-field gel electrophoresis (PFGE) patterns and sequence types (ST). While one patient was considered as having mcr-1-positive carbapenem-resistant E. coli (CREC) colonization, the other three mcr-1-positive CREC-related infections were classified as nosocomial infections. Only amikacin and tigecycline showed good in vitro activity against these four isolates, and three of them had a minimum inhibitory concentration with colistin of ≥4 mg/L. In the colistin-susceptible isolate, mcr-1 was nonfunctional due to the insertion of another gene. In addition, all of the mcr-1-positive CREC contained various resistant genes, such as AmpC
CMY , blaNDM , blaTEM , blaSHV , and blaCTX . In addition, one strain (EC1037) had loss of the OMP. Conclusions: The emergence of the mcr-1 gene among CRE, especially E. coli, remains worth our attention due to its resistance to most antibiotics, and a further national survey is warranted. [ABSTRACT FROM AUTHOR]- Published
- 2019
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