A review of the novel thermophilicCampylobacter,Campylobacter hepaticus,a pathogen of poultry

Abstract

In 2015, a novel thermophilic Campylobacter was isolated from cases of spotty liver disease in laying hens in the UK. In 2016, it was isolated from laying hens in Australia where it was formally named Campylobacter hepaticus and confirmed as the cause of spotty liver disease. It has also been isolated from laying hens in America. It is fastidious, grows slowly on first isolation and does not grow on media used to routinely isolate Campylobacter. Spotty liver disease is an acute, randomly distributed, focal, necrotic hepatitis causing mortality in up to 10% of a flock and a 10%–15% fall in egg production. It occurs mainly in free‐range hens or hens reared on the ground at around the time of peak lay. The incidence of the disease has increased in countries where there is an increase in keeping free‐range laying hens. It is similar to the condition avian vibrionic hepatitis which was reported in America, Europe and Australasia in the 1950s to 1970s and the agent isolated from cases of avian vibrionic hepatitis and C. hepaticus appear to be very similar. It is not known if C. hepaticus is zoonotic but whole genome sequencing shows that it is most closely related to the known zoonotic campylobacters Campylobacter jejuni and Campylobacter coli. Human exposure to C. hepaticus is likely through similar exposure routes. Analysis of the whole genome showed a reduction in the genes for iron metabolism compared to C. jejuni. A requirement for iron was confirmed as it showed reduced growth in an iron depletion assay and this may explain its tissue tropism. With a move towards free‐range egg production in many countries, the incidence of C. hepaticus hepatitis is likely to increase, but the identification of the causal agent will provide opportunities for the development of control methods.

Point Deletion or Insertion in CmeR-Box, A2075G Substitution in 23S rRNA, and Presence of erm(B) Are Key Factors of Erythromycin Resistance in Campylobacter jejuni and Campylobacter coli Isolated From Central China

“…Campylobacter jejuni and Campylobacter coli are major foodborne pathogens worldwide, and poultry is recognized as the most important reservoir of these pathogens (Crawshaw, 2019;Thomas et al, 2019). Usually, erythromycin is the first-line choice for treatment of campylobacteriosis (Bolinger and Kathariou, 2017).…”

New and alternative strategies for the prevention, control, and treatment of antibiotic-resistant Campylobacter

“…However, a recently identified Campylobacter species, Campylobacter hepaticus, has been shown to cause spotty liver disease (SLD) around the world. 38 SLD manifests as acute infectious hepatitis and is characterized by many multifocal, small necrotic foci on the surface of the liver. It affects mostly free-range layer chickens with up to 15% mortality and 35% reduced egg production.…”

Campylobacter hepaticus, the Cause of Spotty Liver Disease in Chickens: Transmission and Routes of Infection

“…Spotty Liver Disease (SLD) has been a persistent problem in the Australian and UK poultry industries for several decades and its presence in North America has recently been confirmed (1)(2)(3). In Australia, SLD was first noted in the 1980s (4,5) and now the disease is regarded as one of the most important disease challenges for the Australian egg industry (6). Affected flocks can have an acute reduction in egg production of up to 25%, and an increase in mortality of up to 10% (1,2).…”