Heat-labile serotyping of two Campylobacter jejuni strains isolated from patients with Guillain-Barré syndrome and belonging to serotype O19 (Penner)

To better understand the serological relationship of HL77 and HL84 type strains, we used a standard method to determine their heat-stable (HS) O antigens. While C. jejuni HS O19 strains are not particularly common, it was surprising and unusual to observe that both the HL77 and HL84 type strains were found to possess the HS O:19 antigen. After removal of the anti-O19 antibodies by absorption with O19 lipopolysaccharide-sensitized red blood cells, anti-OH4382 and anti-OH4384 antisera still contained antibodies that reacted with the HL type strains 77 and 84, indicating the presence of HL77 and HL84 antigens on both C. jejuni OH4382 and OH4384. Our serological studies provide further evidence that C. jejuni strains of Penner serotype O19 appear to he clonal or closely related in that they share common HS O and HL surface antigens.