Comprehensive analysis of lipo-oligosaccharides in Campylobacter jejuni isolated from Guillain–Barré syndrome and enteritis patients, and healthy controls

**Background**: *Campylobacter jejuni* is one of the most frequent causes of acute gastroenteritis and is associated with post-infectious sequelae such as Guillain–Barre Syndrome (GBS). The lipooligosaccharide (LOS) of *C. jejuni* has been reported as an important determinant to develop GBS. **Objective**: This study aimed to investigate the association of *C. jejuni* LOS classes with GBS and enteritis patients and healthy controls in Bangladesh. **Method**: We studied 30 *C. jejuni* strains from GBS patients, 152 from enteritis patients and 215 from healthy control in Bangladesh. All strains were analyzed by PCR for 14 LOS classes (A-S). **Results**: A total of 314/397 (79%) *C. jejuni* strains assigned to different LOS classes. LOS class A was significantly associated with GBS-associated strains compared to enteritis patients (47% vs 3%, p <0.01) and healthy controls (47% vs 7%, p <0.01). LOS Class B was frequent in GBS (50%), enteritis patients (40%) and healthy controls (53%). LOS class E was identified more frequently in enteritis patients compared to healthy controls (16% and 8% respectively). A total of 28 (7%) *C. jejuni* either from enteritis or healthy controls belonged to one of the following classes D, I, Q, K, N, F, J, or S. Two strains from enteritis patients had LOS class N and two from healthy control had LOS class S, J or F. **Conclusion**: Our study identified LOS class A being responsible for the induction of GBS; however, further effort is warranted for proper classification of the strains which could not be typed by the existing LOS classification scheme.