Molecular epidemiology of Campylobacter jejuni associated with Guillain–Barré syndrome

Campylobacter jejuni is the leading cause of bacterial gastroenteritis and its post-infectious sequelae, Guillain-Barré syndrome (GBS). Disease epidemiology of campylobacteriosis differs between high- and low-income countries. The molecular epidemiology of GBS-associated C. jejuni strains has not been thoroughly studied to understand its population dynamics and unique genomic features. We investigated a genome-based epidemiological analysis of 90 GBS-associated C. jejuni strains from 10 different countries to elucidate bacterial genomic features and epidemiological patterns related to GBS induction. We found 11 clonal complexes (CC) and 25 sequence types (STs) with two prevalent lineages, CC-362 (ST-2993) and CC-22(ST-22). SNP-based phylogenetic analysis revealed, the first sequenced C. jejuni (CC-22) from USA was genetically associated with strains from Bangladesh, Mexico, and China. Lipo-oligosaccharide (LOS) class A was prevalent worldwide (63%). In Bangladesh, 32% (9/28) of sialyltransferase cstII-genes harbored a Threonine at 51st-position, compared to China (60%, 6/10), USA (100%, 2/2), and Netherlands (67%, 4/6). Type-VI secretion system was enriched in Bangladesh (11/38, 29%). Among C. jejuni-integrated elements, CJIE-1 was most common (27/90, 30%). Phase variation was significantly higher in CC-403 strains. These diversified genomic characteristics of GBS-associated C. jejuni enhance our understanding of its pathogenic virulence features and linked epidemiological-pattern in Bangladesh and worldwide.