Swine Enteric Colibacillosis in Spain: Pathogenic Potential of mcr-1 ST10 and ST131 E. coli Isolates

Abstract

This is a wide epidemiological study of 499 E. coli isolates recovered from 179 outbreaks of enteric colibacillosis from pig production farms in Spain during a period of 10 years. Most samples were of diarrheagenic cases occurred during the post-wean period (PWD) which showed to be significantly associated with ETEC (67%) followed by aEPEC (21.7%). On the contrary, aEPEC was more prevalent (60.3%) among diarrheas of suckling piglets, followed by ETEC (38.8%). STEC/ETEC or STEC were recovered in 11.3 and 0.9% of PWD and neonatal diarrhea, respectively. Detection of the F4 colonization factor was not significantly different between isolates recovered from neonatal pigs and those recovered post wean (40.5 versus 27.7%) while F18 was only present among PWD isolates (51.5% of ETEC, STEC, and STEC/ETEC isolates). We also found a high prevalence of resistance to colistin related to the presence of the mcr-1 gene (25.6% of the diarreagenic isolates). The characterization of 65 representative mcr-1 isolates showed that all were phenotypically resistant to colistin (>2 μg/ml), and most (61 of 65) multidrug-resistant (MDR). Six ETEC and one STEC mcr-1 isolates were also carriers of ESBL genes. In addition, other seven mcr-1 isolates harbored mcr-4 (three ETEC) and mcr-5 (two ETEC and two aEPEC) genes. In the phylogenetic analysis of the 65 mcr-1 diarrheagenic isolates we found that more than 50% (38 out of 65) belonged to A-ST10 Cplx and from those, 29 isolates showed the clonotype CH11-24. In this study, we also recovered 18 ST131 isolates including seven mcr-1 carriers. To the best of our knowledge, this would be the first report of ST131 mcr-1 isolation in pigs. Worryingly, the swine mcr-1 ST131 carriers also showed MDR, including to trimethoprim-sulfamethoxazole, tobramycin, gentamicin and ciprofloxacin. In the PFGE-macrorestriction comparison of clinical swine and human ST131, we found high similarities (≥85%) between two pig and two human ST131 isolates of virotype D5. Acquisition of mcr-1 by this specific clone means an increased risk due to its special feature of congregating virulence and resistance traits, together with its spread capability. Here we show a potential zoonotic swine source of ST131.

mcr-Colistin Resistance Genes Mobilized by IncX4, IncHI2, and IncI2 Plasmids in Escherichia coli of Pigs and White Stork in Spain

“…In particular, in Spain, mcr-1 has been described circulating in pig farms for many years (Quesada et al, 2016;Garcia-Menino et al, 2018), and our results demonstrate its presence in pig farms in Spain as early as 2005. Although other mcr-gene variants have also been reported in Spain (Carattoli et al, 2017), studies by Garcia-Menino et al (2018) screening large number of E. coli isolates from diagnostic cases of post-weaning diarrhea detected mcr-1 as the most common variant followed by mcr-4. Our study also confirmed similar results, although more recently described mcr-genes have not been tested herein.…”

“…Plasmid mediated colistin resistance has been described worldwide in a variety of Enterobacterales of different origins, environment, food producing animals, wildlife and humans (Zurfluh et al, 2016;Guenther et al, 2017;Ovejero et al, 2017;Barlaam et al, 2019;Elbediwi et al, 2019;Lalaoui et al, 2019;Mendes Oliveira et al, 2019;Nang et al, 2019;Zając et al, 2019). In particular, in Spain, mcr-1 has been described circulating in pig farms for many years (Quesada et al, 2016;Garcia-Menino et al, 2018), and our results demonstrate its presence in pig farms in Spain as early as 2005. Although other mcr-gene variants have also been reported in Spain (Carattoli et al, 2017), studies by Garcia-Menino et al (2018) screening large number of E. coli isolates from diagnostic cases of post-weaning diarrhea detected mcr-1 as the most common variant followed by mcr-4.…”

Escherichia coli ST302: Genomic Analysis of Virulence Potential and Antimicrobial Resistance Mediated by Mobile Genetic Elements

“…The major causative pathotype is enterotoxigenic E. coli (ETEC), which is routinely screened for by veterinary diagnostic laboratories, and characterized by their fimbriae and enterotoxins (Fairbrother et al, 2005). However, though not routinely screened for, aEPEC (eae+, stx−, bfp−) are also known to cause enteric colibacillosis in swine (Fairbrother et al, 2005;Luppi, 2017) and García-Meniño et al (2018) found aEPEC outnumbered ETEC as the causative agents in suckling piglets. Nevertheless, eae+ E. coli has been isolated from both healthy and diarrheic pigs (Krause et al, 2005;Fröhlicher et al, 2008;Malik et al, 2017), implying that a combination of additional VAGs, as well as host-related factors, and poor herd management and husbandry practices, are required to establish disease.…”

Whole Genome Sequencing and Characteristics of mcr-1–Harboring Plasmids of Porcine Escherichia coli Isolates Belonging to the High-Risk Clone O25b:H4-ST131 Clade B

“…The isolates belong to extensive epidemiological studies accomplished in Spain. The seven isolates from diarrheic piglets were isolated during period 2006(García-Meniño et al, 2018 and the four from pork meat during the years (Herrera Estévez, 2015.…”

“…Worryingly, resistance to last-resort antibiotics such as carbapenems and polymyxins has already been reported in the pandemic E. coli clone ST131 (Trobos et al, 2009;Schink et al, 2013;Hasman et al, 2015;Ewers et al, 2016;Kuo et al, 2016;Sonnevend et al, 2016;de Toro et al, 2017;Ortiz de la Tabla et al, 2017;García-Meniño et al, 2018;Ellaby et al, 2019;Hojabri et al, 2019;Reid et al, 2019). Colistin (polymyxin E) is associated with nephrotoxicity and neurotoxicity.…”