LOCAL IMMUNE-RESPONSE IN HELICOBACTER PYLORI-INFECTED CATS AND IDENTIFICATION OF HELICOBACTER-PYLORI IN SALIVA, GASTRIC FLUID AND FECES

Helicobacter pylori-infected cats were screened by culture and polymer ase chain reaction (PCR) for the presence of H. pylori in salivary sec retions, gastric juice, gastric tissue and faeces. H. pylori was cultu red from salivary secretions in six of 12 (50%) cats and from gastric fluid samples in 11 of 12 (91%) cats. A 298 base pair polymerase chain reactions (PCR) product specific for an H. pylori 26 000 MW surface p rotein was amplified from dental plaque samples from five of 12 (42%) cats and from the faeces of four of five (80%) cats studied. Analyses of serum and mucosal secretions by enzyme-linked immunosorbent assay ( ELISA) revealed an H. pylori-specific immunoglobulin G (IgG) response, and elevated IgA anti-H. pylori antibody levels in salivary and local gastric secretions. Immunohistochemical analyses of gastric tissue re vealed the presence of IgM(+) B cells assembled into multiple lymphoid follicles surrounded by clusters of CD4(+) and CD8(+) T cells. The la mina propria also contained single cells or aggregates of IgA(+) and I gM(+) B cells. These observations show that H. pylori can be identifie d in feline mucosal secretions, and that a localized IgA immune respon se develops in gastric tissue of H. pylori-infected cats. The findings suggest a zoonotic risk from exposure to personnel handling H. pylori -infected cats in vivaria.