Campylobacter jejuni strain discrimination and temperature-dependent glycome expression profiling by lectin microarray

Abstract

Gram-negative Campylobacter jejuni is the leading cause of bacterial gastroenteritis in humans worldwide and the most frequently identified infectious trigger in patients developing Guillain-Barré syndrome (GBS). While C. jejuni is pathogenic in humans, it is a commensal in avian hosts. Bacterial cell surface carbohydrates are important virulence factors and play roles in adherence, colonisation and infection. The mechanisms leading to infection or persistent colonisation of C. jejuni are not well understood but host temperature may provide an important stimulus for specific adaptation. Thus, examination of the modulation of the total surface glycome of C. jejuni in response to temperature may help shed light on commensal and pathogenic mechanisms for this species. C. jejuni strains 81116 and 81-176 were cultured at 37 and 42°C to simulate human and avian host conditions, respectively, and whole cells were profiled on lectin microarrays constructed to include a wide range of binding specificities. C. jejuni 81116 profiles indicated that the previously characterised lipopolysaccharide (LPS)-like molecule and N-linked glycans were the predominantly recognised cell surface structures while capsular polysaccharide (CPS), lipooligosaccharides (LOS) and N-linked glycosylation were best recognised for strain 81-176 at 37°C. The profiles of both strains varied and were distinguishable at both temperatures. At the higher temperature, reduced dominance of the LPS-like structure was associated with strain 81116 and a change in the relative distribution of CPS and LOS structures was indicated for strain 81-176. This change in LOS molecular mass species distribution between temperatures was confirmed by SDS-PAGE analysis. Additionally, opposite behaviour of certain lectins was noted between the plate agglutination assay and the microarray platform. Insights into the important glycosylation involved in C. jejuni host cell tropism at different growth temperatures were gained using the lectin microarray platform.

Keywords: Campylobacter jejuni; Capsular polysaccharide; Lectin microarray; Lipooligosaccharide; Lipopolysaccharide; Virulence factors.