Plasmid-mediated colistin resistance mcr-1 in a clinical isolate of Escherichia coli ST19 in Algeria

Abstract

We describe the emergence of plasmid-mediated colistin resistance mcr-1 in a clinical isolate of Escherichia coli ST19. The strain was isolated from a urine sample of a 75-year-old male patient. The identification was carried out by an automated system. The antibiogram was performed according to CLSI recommendations. The colistin MIC was determined by broth micro-dilution according to CA-SFM/EUCAST criteria. The detection of mcr-1 was carried out by immunochromatographic test and PCR mcr-1. Genetic transfers and determination of the plasmid incompatibility group were made. The ST was carried out by MLST using the Pasteur scheme. The strain has a high-level penicillinase resistance phenotype. It was susceptible to amikacin and resistant to gentamicin, tobramycin, fluoroquinolones, tetracycline, chloramphenicol, and cotrimoxazole. The strain was resistant to colistin (MIC ꞊ 4 μg/ml). The genetic transfer is given a colistin-resistant transconjugant. The plasmid carrying mcr-1 gene belongs to the incompatibility group IncHI2.The strain belongs to ST19. J Microbiol Infect Dis 2019; 10(4):222-224.