The FISH assay was evaluated both by spiking poultry faecal samples with Campylobacter jejuni and by detecting Campylobacter in naturally colonized chickens. C. jejuni was reliably detected at levels of 106 cfu/g faeces after a 3- h enrichment step in Blood Preston Selective broth. Low level contaminations (≤ 102 cfu/g) were reliably identified after 24 h of enrichment. By screening cloacal swab samples obtained from birds from a poultry slaughterhouse, thermotolerant Campylobacter spp. were even detected without pre-enrichment.
Moreover, the in situ assay was applied on poultry liver samples. The probes allowed a direct, specific detection of thermotolerant Campylobacter in cryosectioned liver samples.
Campylobacter spp. detection by FISH using highly specific probes looks promising to become a future monitoring system in a logistic poultry slaughter concept.