Prevalence of Campylobacter hepaticus specific antibodies among commercial free-range layers in Australia

Abstract

Spotty liver disease (SLD) caused by Campylobacter hepaticus affects the health and productivity of layer hens and is a disease of concern in poultry. In this study, blood and cloacal swab samples were collected from 709 birds across 11 free-range layer farms from different regions of Australia. The prevalence of C. hepaticus specific antibodies and DNA was assessed using a C. hepaticus specific ELISA and PCR and its correlation with mortalities and changes in egg production was analyzed to better understand the seroprevalence of C. hepaticus in Australian free-range layer farms. C. hepaticus specific antibodies were detected from birds in four of the five farms that had no history of SLD with seroprevalence as high as 41% in one of the farms. Seroprevalence of anti-C. hepaticus antibodies among flocks that had an active or previous SLD outbreak varied between 2 and 64%. C. hepaticus DNA was detected from birds in three farms with no known SLD history and five farms with confirmed SLD outbreaks. A good correlation was observed between the ELISA and PCR results with a Pearson correlation coefficient value of 0.85 (p-value = 0.001). No correlation was observed between the flock size or flock age and ELISA or PCR outcomes, and no significant difference between the seroprevalence of anti-C. hepaticus antibodies among flocks with or without a known history of SLD was established (p = 0.143). This study demonstrates the usefulness of C. hepaticus specific ELISA and PCR in identifying the occurrence of mild or sub-clinical SLD and provides a broader and more complete understanding of SLD epidemiology that will inform future research aimed at the development of methods to control SLD, such as appropriate biosecurity measures, vaccines, and feed additives.

Descriptive epidemiology of spotty liver disease in Australian cage-free brown egg layer chicken flocks with a scratch area

“…It is evident that C. hepaticus may be present and circulating in a flock of hens well before an outbreak of SLD occurs and may be present in flocks that never show a disease outbreak. This has also been observed by Phung et al (2020) and Muralidharan et al (2022). This was shown first by detection of positive C. hepaticus antibody serology, some weeks before cloacal swabs began to expose its presence, within the small 12 sample size employed in this study.…”

“…Two earlier surveys showed a prevalence of 45% and 43.5% respectively where houses had fully slatted floors ( Gao et al, 2023a ; Gao et al, 2023b ). A study by Muralidharan et al (2022) reported 6 out 12 flocks had experienced clinical SLD, but the individual house designs were not declared. The objective of the present study was to provide descriptive epidemiological information on the occurrence of SLD in Australian cage-free flocks where the house incorporated a scratch area.…”

“…Cloacal swabs and dust were assayed for the presence of C. hepaticus DNA as described above. The sera samples were subjected to a C. hepaticus antibody ELISA, as described by Muralidharan et al ., (2022) .…”

“…Spotty liver disease affects adult hens in cage-free production systems and has been reported as capable of causing considerable mortality (10–15%) and a drop in egg production of up to 35% ( Grimes and Reece, 2011 ; Courtice et al, 2018 ). Examples of egg production drops and mortality have been reported by Muralidharan et al (2022) .…”

The use of filamentous hemagglutinin adhesin to detect immune responses to Campylobacter hepaticus infections in layer hens

“…Nevertheless, considering the extra resources and time required for performing the pre-absorption step in SLD-ELISA1, SLD-ELISA2 is a more convenient option, especially when working with large sample sizes as in the identification of the seroconverted birds in farms or in assessing the immune response of birds in large scale experimental infection studies. SLD-ELISA2 has been used to assay sera samples collected from more than 700 birds in commercial free-range farms to better understand the seroprevalence of anti- C. hepaticus antibodies in Australian free-range farms ( 42 ).…”