Publikationsdatenbank

Transmission processes of ESBL-/AmpC-producing Enterobacteriaceae in the broiler production chain (2021)

Art

Hochschulschrift

Autor

Boll, Katrin (WE 10)

Quelle

Berlin, 2021 — II, 84 Seiten

Sprache

Englisch

Verweise

URL (Volltext): https://refubium.fu-berlin.de/handle/fub188/32373

Kontakt

Institut für Tier- und Umwelthygiene

Robert-von-Ostertag-Str. 7-13
14169 Berlin
+49 30 838 51845
tierhygiene@vetmed.fu-berlin.de

Abstract / Zusammenfassung

ESBL-/AmpC-producing Enterobacteriaceae represent a problem both in human and veterinary medicine. High prevalence for these resistant bacteria especially were demonstrated for broiler fattening farms and also on slaughterhouse level as well as in chicken retail meat. In chicken, blaCTX-M1 and blaCMY-2 are the most frequent detected ESBL-/AmpC-resistance genes. In contrast, the most determined beta-lactamase genes in humans are blaCTX-M14 and blaCTX-M15. These genes are also found in chicken, but with low prevalence. Nevertheless, an impact of animal-originated bacteria on public health is assumed and might occur due to direct contact or the consumption of contaminated meat. Regarding these facts, intervention strategies facilitating a reduction of the load of ESBL-/AmpC-producing Enterobacteriaceae in chicken should be considered. Therefore, information on transmission pathways of these bacteria into the broiler farms are needed, however, little was known about it. Earlier studies have assumed the vertical transmission of pathogenic E. coli and as ESBL-/AmpC-producing Enterobacteriaceae even were detected in day-old chicken and (grand)parent flocks, first indications for the vertical transfer of these resistant bacteria were given. On the other hand, other studies assume that contaminated farm environment could represent a source for ESBL-/AmpC-producing Enterobacteriaceae. This transmission is defined as horizontal transmission. The presented study within in RESETII-consortium intended to elucidate possible transmission routes of ESBL-/AmpC-producing Enterobacteriaceae along the entire broiler production chain. Therefore, seven ESBL-/AmpC-positive parent flocks, their corresponding hatching eggs and hatchlings in the hatchery as well as the respective fattening chicken were investigated. For detailed information on the horizontal transmission, two flocks fattened consecutively in the same barn were included in this study. Additionally, within the RESETII-consortium, the same flocks were also investigated at the slaughterhouse, enabling an assessment of transmission routes including that stage of the broiler production chain (Institute of Food Safety and Food Hygiene, FUB, thesis of Philine von Tippelskirch). By using whole genome sequencing to determine phylogenetic relationships we showed that the transmission and entry of ESBL-/AmpC-producing Enterbacteriaceae occurs at different stages of the broiler production chain. On the one hand, the pseudo-vertical transmission route was demonstrated. Thereby the introduction of resistant strains from a parent flock into the hatchery occurs which can result in a positive fattening flock due to the uptake of the bacteria in the hatchery (Publication II). On the other hand, we demonstrated the horizontal transmission route. This transmission pathway occurs due to contaminated housing environment resulting in the subsequent flock being positive for the resistant Enterobacteriaceae (Publication I). Due to the intensive investigation of broiler chicken in their first three days of life concerning the detectability of Enterobacteriaceae we showed that samplings in recently restocked chicken forthe detection of ESBL-/AmpC-producing Enterobacteriaceae using cloacal swabs should not be performed within the first 24 hours of life (Unpublished data). Indications for the subsequent transmission of resistant bacteria from fattening farms into the slaughterhouse as well as cross-contamination at slaughterhouse level were shown as well within the RESETII-consortium at the Insitute of Food Safety and Food Hygiene, FUB. In summary, transmission pathways of ESBL-/AmpC-producing Enterobacteriaceae in the broiler production chain are immensely complex and occur in all stages of the production chain. Therefore, intervention strategies to reduce the load of ESBL-/AmpC-producing Enterobacteriaceae in chicken should be considered at all levels.