Detection of mcr-1 gene in Escherichia coli from companion animals in Argentina.

RUMI MARÍA VALERIA; DI CONZA JOSÉ; PEREYRA A; GENTILINI ELIDA; GUTKIND GABRIEL

New Orleans

Congreso; ASM MICROBE 2017; 2017

American Society for Microbiology

Colistin (COL) is still one of the last line therapy options against infections caused by multidrug-resistant (MDR) Gram-negative pathogens. The recent emergence of a plasmid-borne colistin resistance gene (mcr-1) has alerted the health authorities, and led to changes in how is perceived globally. The mcr-1 gene was first reported in 2015 in food, animal, and patient isolates from China. Taken into account its genetic localization, this mechanism could be spreading among other bacterial species.The aim of this study was to detect mcr-1gene in Enterobacteriaceae isolated from urinary tract infection from pets and to characterize others resistance mechanisms associated. A total of 54 Enterobacteriaceae were collected from urinary samples from dogs and cats during April- June, 2014 from Buenos Aires, Argentina. Identification was determined by conventional biochemical test and confirmed by MALDI-TOF. Susceptibility pattern was determined by the disk diffusion method according to CLSI. Interpretative criteria used for a 10-μg COL disk inhibition zone were: ≤11 mm as resistance and ≥12 mm as susceptibility. Multidrug-resistance (MDR) was considered when the isolates were resistant to three or more antibioticsof different families. Screening for extended spectrum β-lactamases (ESBL) production were conducted by double disk synergy test. ESBL and MCR-1 coding genes were investigated by PCR. The main Escherichia coli phylogenetic groups were assessed by PCR according to Clermont et al. Out of 54 isolates recovered in this period, the more prevalent was E. coli(30), followed by Klebsiella pneumoniae (9), Proteus mirabilis (8), Enterobacter cloacae (4), Enterobacter aerogenes (2) and Serratia marcescens (1).A profile of MDR was detected in 26/54 isolates (48%). Only one mcr-1?harboring E. coli isolates was detected from a dog. This strain (E. coli v80) was phenotypically categorized as COL resistant but was also resistant to ampicillin, cefotaxime, gentamicin and quinolones. E. coli v80 (phylogenetic group B2) was also ESBL-producer. This β-lactamase was characterized as CTX-M-2 by sequencing.These findings suggest that mcr-1?producing E. coli is present in pets with clinical infections. Also suggest that, in addition to food animals and humans, companion animals can actas a reservoir of COL-resistant E. coli, adding another layer of complexity to the rapidly evolving epidemiology of plasmid-mediated colistin resistance in the community. As far as we know, this is the first detection of mcr-1 in E. coli isolated from pets from Argentina.