The aim of this study was to assess the prevalence and risk factors for faecal carriage of extended-spectrum β-lactamase (ESBL) and plasmidic AmpC β-lactamase (pAmpC) Escherichia coli producers in dogs. A three-month cross-sectional study was conducted and 151 rectal swabs were obtained from healthy dogs. ESBL and pAmpC genes were detected by PCR and were sequenced. Logistic regression models were used to investigate risk factors for the carriage of ESBL and pAmpC-producing E. coli. About 15 per cent of the isolates carried ESBL genes (blaCTX-M-32 n=8, blaCTX-M-15 n=5, blaCTX-M-1 n=3, blaCTX-M-9-like n=4) and 20 per cent carried pAmpC genes (blaCMY-2 n=23, blaCMY-2-like n=2). Thirteen dogs carried an E. coli isolate with both an ESBL and a pAmpC gene. One E. coli isolate harboured the human blaDHA-1 pAmpC gene, which has not been previously reported in companion animals in Europe. Dogs with a history of antimicrobial therapy in the past year had a higher risk of being carriers of ESBL-producing (P=0.003, OR =7.85) and pAmpC-producing (P=0.005, OR=6.28) E. coli. Dogs from shelter/breeders were approximately three times more likely to have an ESBL- or a pAmpC-producing E. coli than dogs from private owners. Males have a reduced risk of carrying a pAmpC-producing E. coli than females (P=0.017, OR =0.28). The knowledge of potential risk factors may help to limit the impact of resistance through implementation of effective control measures and judicious antimicrobial therapy.

This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Background:The extended-spectrum ␤-lactamases (ESBL) Ambler's class A are capable of hydrolyze broad spectrum penicillin and cephalosporins, and mostly are codified by plasmidial genes. Health-care associated infections (HAI) are a group of entities with a high frequency worldwide, specially in critical adult patients and children in Intensive Care Units (ICU). The frequency of ESBL in this kind of patients is unknown nowadays in ICU in Cartagena de Indias D.T., Bolívar Colombia.Methods & Materials: The goal of this project was to describe the epidemiology of ESBLS type TEM and SHV in the city of Cartagena de Indias D.T state of Bolívar in Colombia. Clinical samples (blood, urine, LRT secretion, surgical site secretion) were collected from adult patients under HAIs diagnosis (Ventilator Associated Pneumonia, Bloodstream Infection, Urinary Tract Infection, Surgical Site Infection). Phenotypic identification, susceptibility test and antibiotic profile was performed with an automatized method according the current CLSI standards, following of genotypic identification with molecular biology methods as PCR and sequencing to confirm the presence of TEM and SHV genes in susceptible and resistant bacteria.Results: The presence of ESBLS type TEM and SHV was frequent in the samples collected, finding that the presence of TEM/SHV at the same time was found in 43.3% of the samples and TEM ESBL was the most frequent, these findings were observed in susceptible and resistant bacteria. K pneumoniae was the most frequent bacteria (33.3%) follow by P. aeruginosa (28,9%) with TEM and SHV genes in susceptible and resistant samples at the same time. Conclusion:The presence of ESBL type TEM and SHV in susceptible and resistant bacteria in Health-care associated infections (HAI) in Intensive Care Units (ICU) patients has an importance in antibiotic therapy and prognosis of this kind of patients worldwide. Silenced genes in susceptible strains has been described in this kind of isolates, in Cartagena, Colombia this kind of findings are new, and could be part of the reason of the negative outcome on these patients.