Dynamics of CMY-2 producing E. coli in a broiler parent flock

Abstract

A B S T R A C TExtended-spectrum β-lactamase and plasmid mediated AmpC β-lactamase (ESBL/pAmpC) producing bacteria are resistant to Extended Spectrum Cephalosporins (ESC), and are present in all levels of the broiler production chain. We determined the prevalence, concentration, and persistence of ESBL/pAmpC-Escherichia coli in a broiler parent flock during the rearing and laying period. One-day old chickens were housed in four separate pens. Until week 33 no antibiotics or coccidiostatics were used. During rearing 57 chickens in each pen (n = 228), and in the laying period two groups of 33 chickens were individually sampled (n = 66). Environmental samples were taken from week 16 onwards. ESBL/pAmpC-E. coli presence was determined by selective culturing. In the samples of week 16-19 the concentration of ESBL/pAmpC-E. coli was determined. All ESC-resistant isolates found were positive for pAmpC gene bla CMY-2 located on IncA/C plasmids, in several E. coli MLST types. CMY-2-E. coli prevalence decreased from 91% (95%CI 86-94%) at day 7 (week 1) to 0% (95%CI 0-5%) in week 21. However, CMY-2-E. coli remained present in the environmental samples during the whole study. CMY-2-E. coli concentration varied between detection limit (< 10^3) and 2·10^4 cfu/g faeces. The sharp reduction of CMY-2-E. coli in this broiler parent flock in absence of antibiotics suggests a selective disadvantage of bla CMY-2 on IncA/C plasmids on animal level. The underlying mechanism should be studied further as this may provide new insights on how to reduce ESBL/pAmpC prevalence and transmission in the broiler production chain.

Effect of ceftiofur cessation and substitution with lincomycin-spectinomycin on extended-spectrum-beta-lactamase/AmpC genes and multidrug resistance in E. coli from a Canadian broiler production pyramid

“…The lower prevalence of bla CTX-M with respect to bla CMY- 2 in our study in contrast to the lower prevalence of bla CMY- 2 reported in Europe (5) could be due to the presence of different plasmids containing bla CTX-M in Europe such as IncN, IncI, IncL/M and IncK (8). Nevertheless, a more recent study in Europe showed a higher proportion of bla CMY-2 (28). The difference in relative predominance of the bla CTX-M and bla CMY-2 .genes could also be explained in part by differences in geographical distribution of these genes (7).…”

“…The presence of such plasmids in our study may explain why multidrug-resistant bacteria were selected when using lincomycin-spectinomycin at the hatchery. Studies in Japan and Netherlands also found IncA/C plasmids harboring bla CMY-2 and resistance to non β-lactam antimicrobial (28, 33). The plasmids selected in our study may have contained bla CMY-2 genes and other resistance genes.…”

“…In the Danish study, a decrease in prevalence of samples positive for cephalosporin resistant E. coli to 27% in broiler flocks originating from breeders which did not receive ceftiofur (19). Finally, maintenance of the high proportion positive samples in the Canadian broilers at one year after the cessation of administration of ceftiofur could also be explained by environmental contamination which may have persisted after birds ceased to excrete E. coli positive for ESBL/AmpC resistance genes (28).…”

“…We observed a significant decrease in non-susceptibility to trimethoprim-sulphamethoxazole in the broiler feces for the flocks which did not receive any antimicrobial in ovo following the cessation of ceftiofur, thus demonstrating the potential for a positive cessation effect for this class of antimicrobials. This decrease could be explained by a selective disadvantage of bla CMY-2 on certain plasmids at the animal level when ceftiofur is stopped and no antimicrobial is used subsequently (28). Furthermore, resistance to phenicols and tetracyclines were lower, although not significantly, for these same flocks, showing a beneficial effect with respect to the prevalence of MDR.…”

Embryo survival and efforts to reduce ESBL cross contamination in the hatchery using One2Born hatcher baskets

“…One way to solve the problem of cross-contamination in the hatchery could be on-farm hatching. In this system, eggs are transferred from the hatchery to the farm after 18 days of incubation, which is three days before hatch (Velkers et al, 2016(Velkers et al, , 2017, thereby avoiding intense exposure of chicks to possible adverse environmental conditions (temperature, dust, fluff) in hatchers, the chick processing room, and the chick holding room (before transport) as described in in De Gouw et al, 2017. In a study by Ceccarelli et al (unpublished results) the hatchery and especially the chick processing room appeared to be a reservoir of ESBL producing E-coli bacteria.…”