Clonal Spread of Escherichia coli ST93 Carrying mcr-1-Harboring IncN1-IncHI2/ST3 Plasmid Among Companion Animals, China

Abstract

The purpose of this study was to investigate the occurrence of plasmid-mediated colistin resistance gene mcr-1 in Enterobacteriaceae isolates from companion animals in Guangzhou, China. Enterobacteriaceae isolated from 180 samples collected from cats and dogs were screened for mcr-1 by PCR and sequencing. MCR-1-producing isolates were further characterized by multilocus sequence typing and pulsed-field gel electrophoresis (PFGE). Plasmid characterization was performed by conjugation, replicon typing, S1-PFGE, and Southern blot hybridization. Plasmid pHN6DS2 as a representative IncN1-IncHI2/ST3 plasmid from ST93 E. coli was fully sequenced. pHN6DS2-like plasmids were screened by PCR-mapping and sequencing. The mcr-1 gene was detected in 6.25% (8/128) Escherichia coli isolates, of which, five belonged to E. coli ST93 and had identical PFGE patterns, resistance profiles and resistance genes. mcr-1 genes were located on ∼244.4 kb plasmids (n = 6), ∼70 kb plasmids, and ∼60 kb plasmids, respectively. Among them, five mcr-1-carrying plasmids were successfully transferred to recipient by conjugation experiments, and were classified as IncN1-IncHI2/ST3 (∼244.4 kb, n = 4, all obtained from E. coli ST93), and IncI2 (∼70 kb, n = 1), respectively. Plasmid pHN6DS2 contained a typical IncHI2-type backbone, with IncN1 segment (ΔrepA-Iterons I-gshB-ΔIS1294) inserted into the multiresistance region, and was similar to other mcr-1-carrying IncHI2/ST3 plasmids from Enterobacteriaceae isolates of various origins in China. The remaining five mcr-1-bearing plasmids with sizes of ∼244.4 kb were identified to be pHN6DS2-like plasmids. In conclusion, clonal spread of ST93 E. coli isolates was occurred in companion animals in Guangzhou, China.

First Report of an Escherichia coli Strain Carrying the Colistin Resistance Determinant mcr-1 from a Dog in South Korea

“…PCR and sequencing analysis identified the mcr-1 gene in one of the colistin-resistant isolates. The mcr-1 prevalence in E. coli isolates in this study was lower than those previously reported in E. coli recovered from companion animals in Argentina (1.9%) [25], Beijing, China (2.3%) [27], and Guangzhou, China (6.25%) [28]. However, it was almost similar to our previously described mcr-1 detection in food animals in Korea [12].…”

High Prevalence and Diversity of Cephalosporin-Resistant Enterobacteriaceae Including Extraintestinal Pathogenic E. coli CC648 Lineage in Rural and Urban Dogs in Northwest Spain

“…E. coli ST93 were reported in wild birds in Pakistan, associated with the carriage of bla CTX-M-15 [ 28 ]; in beef, veal, pork and poultry, associated with bla CTX-M-1 in Switzerland [ 28 ]; and in broiler chickens carrying bla CTX-M-2 in Brazil [ 39 ]. In addition, ST93 was also associated to the spread of the mcr -1 gene in companion animals and retail food in China [ 40 , 41 ]. Regarding infections in humans, mcr -1-carrying ST93 E. coli was recovered from a patient with bacteremia in Uruguay [ 42 ].…”

Farm animals and aquaculture: significant reservoirs of mobile colistin resistance genes

“…However, levels of colistin resistance are consistently low. The gene mcr-1 has also been identified in bacteria from sheep (Tang et al, 2019), poultry (ducks, geese, and pigeons) (Zhang et al, 2018;Zhuge et al, 2019), companion animals (dogs and cats) (Sun et al, 2016;Zhang et al, 2016;Lei et al, 2017;Wang et al, 2018a;Ortega-Paredes et al, 2019;Rumi et al, 2019), and even wild animals (Liakopoulos et al, 2016;Mohsin et al, 2016;Ruzauskas and Vaskeviciute, 2016;Unger et al, 2017;Bachiri et al, 2018;Oteo et al, 2018) (Table 1 and Supporting Information Table S1). The first report of a wild animal carrying mcr-1 gene could be traced back to 2012, when Liakopoulos et al identified five mcr-1-positive E. coli from Larus dominicanus (n = 50) in Argentina, and all mcr-1 genes were located on IncI2 plasmids (Liakopoulos et al, 2016).…”