Speaker: Dr Ozan Gundogdu, London School of Hygiene and Tropical Medicine will present a seminar entitled:

Molecular and bioinformatic analyses to inform intervention strategies to reduce Campylobacter jejuni infection of chickens

Host: Andrew Page

Abstract:

Campylobacter jejuni is present within the chicken gut and is the leading cause of bacterial foodborne gastroenteritis within humans worldwide. Infection can lead to secondary sequelae such as Guillain-Barré syndrome and stunted growth in children from low-resource areas. Despite the microaerophilic nature of the bacterium, C. jejuni can survive the atmospheric oxygen conditions in the environment. Bacteria that can survive either within a host or in the environment like C. jejuni require variable responses to survive the stresses associated with exposure to different levels of reactive oxygen species. Recently we have shown the MarR-type transcriptional regulators RrpA and RrpB to play a role in controlling both the C. jejuni oxidative and aerobic stress responses. Analysis of 3,746 C. jejuni and 486 C. coli genome sequences showed that whilst rrpA is present in over 99% of C. jejuni strains, the presence of rrpB is restricted and appears to correlate with specific MLST clonal complexes (predominantly ST-21 and ST-61). The oxidative and aerobic stress responses of rrpB- and rrpB+ strains suggest adaptation of C. jejuni within different hosts and niches that can be linked to specific MLST clonal complexes. In addition, how and when C. jejuni appears within chickens remains unclear. The lack of day to day microbiome data with replicates, relevant metadata, and a lack of natural infection studies have delayed our understanding of the chicken gut microbiome and C. jejuni. Here, we performed a comprehensive day to day microbiome analysis of the chicken cecum from day 3 to 35 (12 replicates each day; final n = 379). We combined metadata such as chicken weight and feed conversion rates to investigate what the driving forces are for the microbial changes within the chicken gut over time, and how this relates to C. jejuni appearance within a natural habitat setting. We believe that our findings can be useful for future intervention strategies and help reduce the burden of Campylobacter within the food chain.

Summary
Campylobacter jejuni is present within the chicken gut and is the leading cause of bacterial foodborne gastroenteritis within humans worldwide. Despite the microaerophilic nature of the bacterium, C. jejuni can survive atmospheric oxygen conditions and is omnipresent within the environment. How the bacteria is able to do so remains a conundrum. In addition, how and when C. jejuni infects chickens remains unclear. We have investigated the survival properties of C. jejuni using both molecular and bioinformatic based approaches to try and inform intervention strategies to reduce C. jejuni infection of chickens.

All staff from organisations on the Norwich Research Park are welcome to attend.