Off-label use of ceftiofur in one-day chicks triggers a short-term increase of ESBL-producing E. coli in the gut

Abstract

This trial was designed to evaluate the off-label use of ceftiofur with Marek’s vaccine in one-day-old broiler chicks, a prophylactic treatment that has been done in some commercial hatcheries, on the emergence of extended-spectrum beta-lactamase producing Escherichia coli (ESBL-E. coli). A total of 168 chicks (Cobb500®) were used in a completely randomized design. Birds were assigned to two treatments (Marek’s vaccine plus saline vs Marek’s vaccine plus ceftiofur) and six repetitions, with 14 animals each. Cloacal swabs were collected from 1 to 14 days post-hatch. The majority (86%; p<0.0001) of the ESBL-producing isolates harboring blaCTX-M and blaSHV genes originated from animals receiving the antimicrobial. None of the isolates were positive for plasmid-mediated AmpC betalactamase genes (blaACC, blaCMY-2, blaDHA, blaFOX, blaMOX and blaMIR). These findings indicate that the off-label use of ceftiofur with Marek’s vaccine is associated with the short-term increase in ESBL-producing Escherichia coli in the gut of chicks.

High occurrence of β-lactamase-producing Salmonella Heidelberg from poultry origin

“…These results are in accordance with previous works which reported cephalosporin-resistance in Salmonella from food-producing animals and poultry meat, since early 2000s [9,35,36]. Third-generation cephalosporin, as ceftiofur, have been frequently used in day-old chicks together with Marek's vaccine [16], and it is related to short-term antimicrobial resistance in Enterobacteriaceae [13,14].…”

“…Despite that CEF is not a common cephalosporin used in human medicine, previous studies have shown a strict relationship between it and CTX resistance in Enterobacteriaceae [13,37]. We found complete agreement in that CEF and CTX resistance.…”

“…Extended spectrum β-lactamase genes were identified in seven of 62 SH strains studied: bla CTX-M , 3.22% (2/62); bla SHV , 4.83% (3/62); bla TEM-1 , 3.22% (2/62). ESBL-producing Enterobacteriaceae harboring these genes are frequently found from animal and human origin [5,13,38,39]. None of other studied ESBL genes-bla PSE and bla OXA-2 -were found in this study.…”

“…Veterinary prescription is also required but sometimes failures in the official surveillance of antimicrobial use can lead to misuse. It is known that off-label use of some antimicrobials make a selective pressure which have been associated with quickly increased of bacterial resistance in Enterobacteriaceae species, as E. coli, from farms animals [13,14].…”

Antimicrobial Resistance in Farm Animals in Brazil: An Update Overview

“…and E. coli producing bla CTX-M-variants have been detected in poultry farms environment and on the surface of flies from dairy farms, respectively [124,145]. In addition, a study has shown that the prophylactic administration of ceftiofur to one-day-old broiler chicks may be associated with early carriage of ESBL-producing E. coli in the gut of these animals [154]. Table 5 describes the source, geographic location of sampling, and bla genes found in studies that reported ESBL and pAmpC-encoding genes in food or food-producing animals in Brazil. In Salmonella, bla CTX-M-2 was identified in non-transferable and conjugative plasmids of 90 to 290 kb.…”