Ilias Chantziaras1,2, Annemieke Smet2,3, Freddy Haesebrouck2, Filip Boyen2, Jeroen Dewulf1. 1. Veterinary Epidemiology Unit, Department of Reproduction, Obstetrics and Herd Health, Faculty of Veterinary Medicine, Ghent University, 9820 Merelbeke, Belgium. 2. Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, 9820 Merelbeke, Belgium. 3. Laboratory of Experimental Medicine and Pediatrics, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium.
Abstract
Objectives: Factors potentially contributing to fluoroquinolone resistance selection in commensal Escherichia coli strains in poultry were studied through a series of in vivo experiments. The effect of the initial prevalence of enrofloxacin resistance in the E. coli gut microbiota, effect of the bacterial fitness of the enrofloxacin-resistant strain and effect of treatment with enrofloxacin (effect of dose and effect of route of administration) were assessed. Methods: Four in vivo studies with broiler chickens were performed. Right after hatching, the chicks were inoculated with either a bacteriologically fit or a bacteriologically non-fit fluoroquinolone-resistant strain as either a minority or the majority of the total E. coli population. Six days later, the chicks were treated for three consecutive days either orally or parenterally and using three different doses (under-, correct- and over-dose) of enrofloxacin. The faecal shedding of E. coli strains was quantified by plating on agar plates either supplemented or not supplemented with enrofloxacin. Linear mixed models were used to assess the effect of the aforementioned variables on the selection of enrofloxacin resistance. Results: The factors that significantly contributed were treatment ( P < 0.001), bacterial fitness of the resistant donor strain ( P < 0.001), administration route ( P = 0.052) and interactions between bacterial fitness and administration route ( P < 0.001). Conclusions: In the currently used models, fluoroquinolone resistance selection was influenced by treatment, bacterial fitness of the inoculation strain and administration route. The use of oral treatment seems to select more for fluoroquinolone resistance, particularly in the model where a non-fit strain was used for inoculation.
Objectives: Factors potentially contributing to fluoroquinolone resistance selection in commensal Escherichia coli strains in poultry were studied through a series of in vivo experiments. The effect of the initial prevalence of enrofloxacin resistance in the E. coli gut microbiota, effect of the bacterial fitness of the enrofloxacin-resistant strain and effect of treatment with enrofloxacin (effect of dose and effect of route of administration) were assessed. Methods: Four in vivo studies with broiler chickens were performed. Right after hatching, the chicks were inoculated with either a bacteriologically fit or a bacteriologically non-fit fluoroquinolone-resistant strain as either a minority or the majority of the total E. coli population. Six days later, the chicks were treated for three consecutive days either orally or parenterally and using three different doses (under-, correct- and over-dose) of enrofloxacin. The faecal shedding of E. coli strains was quantified by plating on agar plates either supplemented or not supplemented with enrofloxacin. Linear mixed models were used to assess the effect of the aforementioned variables on the selection of enrofloxacin resistance. Results: The factors that significantly contributed were treatment ( P < 0.001), bacterial fitness of the resistant donor strain ( P < 0.001), administration route ( P = 0.052) and interactions between bacterial fitness and administration route ( P < 0.001). Conclusions: In the currently used models, fluoroquinolone resistance selection was influenced by treatment, bacterial fitness of the inoculation strain and administration route. The use of oral treatment seems to select more for fluoroquinolone resistance, particularly in the model where a non-fit strain was used for inoculation.
Authors: Daniela Gaio; Matthew Z DeMaere; Kay Anantanawat; Graeme J Eamens; Linda Falconer; Toni A Chapman; Steven Djordjevic; Aaron E Darling Journal: PLoS One Date: 2022-06-24 Impact factor: 3.752
Authors: Roosmarijn E C Luiken; Liese Van Gompel; Patrick Munk; Steven Sarrazin; Philip Joosten; Alejandro Dorado-García; Rasmus Borup Hansen; Berith E Knudsen; Alex Bossers; Jaap A Wagenaar; Frank M Aarestrup; Jeroen Dewulf; Dik J Mevius; Dick J J Heederik; Lidwien A M Smit; Heike Schmitt Journal: J Antimicrob Chemother Date: 2019-09-01 Impact factor: 5.790
Authors: Joren De Smet; Filip Boyen; Siska Croubels; Geertrui Rasschaert; Freddy Haesebrouck; Robin Temmerman; Sofie Rutjens; Patrick De Backer; Mathias Devreese Journal: BMC Vet Res Date: 2020-10-08 Impact factor: 2.741