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Diverse and emerging molecular mechanisms award polymyxins resistance to Enterobacteriaceae clinical isolates from a tertiary hospital of Recife, Brazil
- Source :
- Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases. 85
- Publication Year :
- 2020
-
Abstract
- Objective To describe the molecular mechanisms of polymyxins resistance in five Enterobacteriaceae clinical isolates from a tertiary hospital of Recife, Brazil. Methods The species identification and the susceptibility to antimicrobials were firstly performed by automatized methods and polymyxin resistance was confirmed by broth microdilution methods. The genetic basis of resistance was characterized with WGS analyses to study their resistome, plasmidome and mobilome, by BLAST searches on reference databases. Results Five (5%) Enterobacteriaceae isolates, comprising Escherichia coli (n = 2), Klebsiella pneumoniae (n = 2) and Citrobacter freundii (n = 1) species, exhibited polymyxin resistance. The mcr-1.1 gene was found in identical IncX4-plasmids harbored by both K. pneumoniae C119 (PolB MIC = 512 mg/L) and E. coli C153 (PolB MIC = 8 mg/L). The remaining E. coli strain C027 harbored the mcr-5.1 gene on an undefined Inc-plasmid (PolB MIC 256 mg/L). Some amino acid substitutions in PmrA (S29G, G144S), PmrB (S202P; D283G, W350*, Y258N) and PhoP (I44L) was detected among the E. coli clinical isolates, however they were also found in colistin-susceptible strains and predicted as neutral alterations. The mgrB of the ST54 KPC-2-producing K. pneumoniae C151 (PolB MIC = 32 g/mL) was interrupted at 69 nt by the IS903 element. The ST117 C. freundii C156 (PolB MIC = 256 mg/L) showed the A91T substitution on HAMP domain of the histidine kinase sensor CrrB, predicted as deleterious and deemed the remarkable determinant to polymyxins resistance in this strain. Conclusions Diverse mechanisms of polymyxins resistance were identified among clinical Enterobacteriaceae from a tertiary hospital of Recife, Brazil, such as plasmid-mediated MCR-1 and MCR-5; IS903-interruption of mgrB and mutation in CrrAB regulatory system. These findings highlight the involvement of the identified plasmids on mcr dissemination among Enterobacteriaceae; warn about co-selection of the polymyxin-resistant and KPC-producer K. pneumoniae ΔmgrB lineage by carbapenems usage; and demonstrate potential role of CrrAB on emerging of polymyxin resistance among Enterobacteriaceae, besides Klebsiella species.
- Subjects :
- 0301 basic medicine
Microbiology (medical)
Klebsiella pneumoniae
medicine.drug_class
Polymyxin
030106 microbiology
Microbial Sensitivity Tests
Biology
medicine.disease_cause
Microbiology
Tertiary Care Centers
03 medical and health sciences
Enterobacteriaceae
Drug Resistance, Bacterial
Genetics
medicine
Polymyxins
Molecular Biology
Escherichia coli
Ecology, Evolution, Behavior and Systematics
Broth microdilution
Enterobacteriaceae Infections
biology.organism_classification
Citrobacter freundii
Resistome
Anti-Bacterial Agents
030104 developmental biology
Infectious Diseases
Genes, Bacterial
MCR-1
Brazil
Plasmids
Subjects
Details
- ISSN :
- 15677257
- Volume :
- 85
- Database :
- OpenAIRE
- Journal :
- Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases
- Accession number :
- edsair.doi.dedup.....b808d557c4147ebf8781ba63941fc972