title: A trend analysis of antimicrobial resistance in commensal Escherichia coli from several livestock species in Belgium (2011-2014).
abstract: A temporal trend analysis was performed on antimicrobial resistance data collected over 4 consecutive years (2011-2014) in the official Belgian antimicrobial resistance monitoring programme. Commensal Escherichia coli strains were isolated from faecal samples of four livestock categories (veal calves, young beef cattle, broiler chickens and slaughter pigs) and the trends of resistance profiles were analysed. The resistance prevalence remained high (>50%) during the study period for ampicillin in veal calves and chickens, for ciprofloxacin and nalidixic acid in chickens, for sulfamethoxazole in veal calves, chickens and pigs and for tetracycline in veal calves. Using logistic regression and Generalized Estimating Equation and after p value adjustment for multiple testing (Linear step-up method), statistically significant decreasing temporal trends were observed for several of the 11 tested antimicrobials in several livestock categories: in veal calves (10/11), in chickens (6/11) and in pigs (5/11). A significant increasing trend was observed for the prevalence of resistance to ciprofloxacin in chickens. Multi-resistance, considered as the resistance to at least three antimicrobials of different antibiotic classes, was observed in the four livestock categories but was significantly decreasing in veal calves, chickens and pigs. Overall, the prevalence of resistance and of multi-resistance was lowest in the beef cattle livestock category and highest in broiler chickens. These decreasing temporal trends of antimicrobial resistance might be due to a decrease of the total antimicrobial consumption for veterinary use in Belgium which was reported for the period between 2010 and 2013. The methodology and statistical tools developed in this study provide outputs which can detect shifts in resistance levels or resistance trends associated with particular antimicrobial classes and livestock categories. Such outputs can be used as objective evidence to evaluate the possible efficacy of measures taken by animal health authorities and stakeholders in the livestock sector to limit antimicrobial resistance occurrence.
authors.affiliation: Veterinary and Agrochemical Research Centre (CODA-CERVA), Groeselenberg 99, 1180 Brussels, Belgium. Electronic address: jbhan@coda-cerva.be.
authors.forename: Jean-Baptiste
authors.initials: JB
authors.lastname: Hanon
authors.affiliation: Interuniversity Institute for Biostatistics and statistical Bioinformatics (I-BioStat), Hasselt University, Agoralaan Building D, 3590 Diepenbeek, Belgium.
authors.forename: Stijn
authors.initials: S
authors.lastname: Jaspers
authors.affiliation: Veterinary and Agrochemical Research Centre (CODA-CERVA), Groeselenberg 99, 1180 Brussels, Belgium; Ghent University, Department of Pathology, Bacteriology and Poultry Diseases, Faculty of Veterinary Medicine, Salisburylaan 133, 9820 Merelbeke, Belgium; Ross University, Department of Biosciences, Basseterre, Saint Kitts and Nevis.
authors.forename: Patrick
authors.initials: P
authors.lastname: Butaye
authors.affiliation: Veterinary and Agrochemical Research Centre (CODA-CERVA), Groeselenberg 99, 1180 Brussels, Belgium.
authors.forename: Pierre
authors.initials: P
authors.lastname: Wattiau
authors.affiliation: Veterinary and Agrochemical Research Centre (CODA-CERVA), Groeselenberg 99, 1180 Brussels, Belgium.
authors.forename: Estelle
authors.initials: E
authors.lastname: Méroc
authors.affiliation: Interuniversity Institute for Biostatistics and statistical Bioinformatics (I-BioStat), Hasselt University, Agoralaan Building D, 3590 Diepenbeek, Belgium.
authors.forename: Marc
authors.initials: M
authors.lastname: Aerts
authors.affiliation: Veterinary and Agrochemical Research Centre (CODA-CERVA), Groeselenberg 99, 1180 Brussels, Belgium.
authors.forename: Hein
authors.initials: H
authors.lastname: Imberechts
authors.affiliation: Federal Agency for the Safety of the Food Chain (FASFC), Food Safety Centre, Boulevard du Jardin Botanique 55, 1000 Brussels, Belgium.
authors.forename: Katie
authors.initials: K
authors.lastname: Vermeersch
authors.affiliation: Veterinary and Agrochemical Research Centre (CODA-CERVA), Groeselenberg 99, 1180 Brussels, Belgium; Ghent University, Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Salisburylaan 133, 9820 Merelbeke, Belgium.
authors.forename: Yves
authors.initials: Y
authors.lastname: Van der Stede
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001530:Belgium / Q000453:epidemiology; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology / Q000382:microbiology*; D002645:Chickens; D024901:Drug Resistance, Multiple, Bacterial; D004926:Escherichia coli / Q000187:drug effects*; D004927:Escherichia coli Infections / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*; D005243:Feces / Q000382:microbiology; D008826:Microbial Sensitivity Tests / Q000662:veterinary; D011201:Poultry Diseases / Q000453:epidemiology / Q000382:microbiology*; D015995:Prevalence; D012621:Seasons; D013552:Swine; D013553:Swine Diseases / Q000453:epidemiology / Q000382:microbiology*
chemical_list: D000900:Anti-Bacterial Agents
keywords: Antimicrobial resistance; Commensal bacteria; E. coli; Monitoring; Surveillance; Trend analysis