Antimicrobial Resistance Genes and Diversity of Clones among Faecal ESBL-Producing Escherichia coli Isolated from Healthy and Sick Dogs Living in Portugal

Abstract

The purpose of this study was to analyse the prevalence and genetic characteristics of ESBL and acquired-AmpC (qAmpC)-producing Escherichia coli isolates from healthy and sick dogs in Portugal. Three hundred and sixty-one faecal samples from sick and healthy dogs were seeded on MacConkey agar supplemented with cefotaxime (2 µg/mL) for cefotaxime-resistant (CTXR) E. coli recovery. Antimicrobial susceptibility testing for 15 antibiotics was performed and the ESBL-phenotype of the E. coli isolates was screened. Detection of antimicrobial resistance and virulence genes, and molecular typing of the isolates (phylogroups, multilocus-sequence-typing, and specific-ST131) were performed by PCR (and sequencing when required). CTXRE. coli isolates were obtained in 51/361 faecal samples analysed (14.1%), originating from 36/234 sick dogs and 15/127 healthy dogs. Forty-seven ESBL-producing E. coli isolates were recovered from 32 sick (13.7%) and 15 healthy animals (11.8%). Different variants of blaCTX-M genes were detected among 45/47 ESBL-producers: blaCTX-M-15 (n = 26), blaCTX-M-1 (n = 10), blaCTX-M-32 (n = 3), blaCTX-M-55 (n = 3), blaCTX-M-14 (n = 2), and blaCTX-M-variant (n = 1); one ESBL-positive isolate co-produced CTX-M-15 and CMY-2 enzymes. Moreover, two additional CTXR ESBL-negative E. coli isolates were CMY-2-producers (qAmpC). Ten different sequence types were identified (ST/phylogenetic-group/β-lactamase): ST131/B2/CTX-M-15, ST617/A/CTX-M-55, ST3078/B1/CTX-M-32, ST542/A/CTX-M-14, ST57/D/CTX-M-1, ST12/B2/CTX-M-15, ST6448/B1/CTX-M-15 + CMY-2, ST5766/A/CTX-M-32, ST115/D/CMY-2 and a new-ST/D/CMY-2. Five variants of CTX-M enzymes (CTX-M-15 and CTX-M-1 predominant) and eight different clonal complexes were detected from canine ESBL-producing E. coli isolates. Although at a lower rate, CMY-2 β-lactamase was also found. Dogs remain frequent carriers of ESBL and/or qAmpC-producing E. coli with a potential zoonotic role.

Characterization of ESBL-Producing Escherichia coli and Klebsiella pneumoniae Isolated from Clinical Samples in a Northern Portuguese Hospital: Predominance of CTX-M-15 and High Genetic Diversity

“…In Germany, this enzyme was also the most prevalent ESBL type (around 50% of the strains investigated) [ 17 ]. Recently, the bla CTX-M-15 gene was the most frequently detected among E. coli of both sick and healthy dogs and cats in Portugal [ 14 , 15 ]. Nevertheless, the bla CTX-M-1 was the most common ESBL gene among healthy students in Portugal (Lisbon), followed by the bla CTX-M-15 gene [ 13 ].…”

“…The CTX-M-15 gene is frequently associated with a specific international lineage, the epidemic clone ST131, which has spread worldwide [ 15 , 57 ]. According to Belas et al (2019) [ 56 ], the E. coli ST131/CTX-M-15/B2 is the most disseminated E. coli clonal group worldwide associated with an extensive antimicrobial resistance profile; this lineage was found among 90% of our E. coli clinical isolates ( Table 1 ), which represent a public health concern.…”

“…Moreover, recent studies reported ESBL-producing K. pneumoniae isolates among urinary tract infections and invasive infections in patients in Portugal [ 4 , 5 , 9 ], as well as among healthy Portuguese students in Lisbon [ 13 ]. Furthermore, a previous report created by our group showed the presence of ESBL-producing E. coli among healthy and sick cats [ 14 ] and dogs [ 15 ] in Portugal.…”

“…In the last decade, E. coli clonal group ST131 has emerged as a high-risk clone with important clinical health concerns causing multidrug-resistant (MDR) infections worldwide [ 11 ]. Particularly in Portuguese territory, ST131 clone was detected among residents of nursing homes [ 22 ], sick dogs [ 15 ], as well as in UTI clinical isolates from humans [ 24 ]. Nevertheless, other high-risk international clones have been detected among ESBL- or carbapenemase-producing E. coli isolates, as is the case of ST410 [ 25 , 26 , 27 ].…”

The Prevalence and Characterization of Fecal Extended-Spectrum-Beta-Lactamase-Producing Escherichia coli Isolated from Pigs on Farms of Different Sizes in Latvia

“…ESBLs are able to confer resistance to penicillin, first-, second-, and third-generation cephalosporin, and monobactam. Most ESBL genes are located in the mobile genetic elements; therefore, horizontal gene transfer has promoted the spread of antibiotic resistance genes among strains and species [ 7 ]. In addition, ESBL-producing Escherichia coli ( E. coli ) has often been found to be co-resistant to other antibiotic classes [ 8 ].…”