Localimmuneresponse inHelicobacter pylori-infected catsandidentification ofH.pylori insaliva, gastric fluid andfaeces

SUMMARY Helicobacter pylori-infected catswere screened byculture andpolymerase chainreaction (PCR) forthepresenceofH.pylori insalivary secretions, gastric juice, gastric tissue andfaeces. H.pylori was cultured fromsalivary secretions insixof12(50%)catsandfromgastric fluid samples in11 of 12(91%)cats. A 298basepair polymerase chain reactions (PCR)product specific for an H.pylori 26000MWsurface protein was amplified fromdental plaque samples fromfive of12(42%)cats andfromthefaeces offouroffive (80%)catsstudied. Analyses ofserum andmucosal secretions by enzyme-linked immunosorbent assay(ELISA) revealed an H.pylori-specific immunoglobulin G (IgG) response,andelevated IgAanti-H. pylori antibody levels insalivary andlocal gastric secretions. Immunohistochemical analyses ofgastric tissue revealed thepresenceofIgM+Bcells assembled into multiple lymphoid follicles surrounded byclusters ofCD4+andCD8+Tcells. The laminapropria alsocontained single cells or aggregates ofIgA+andIgM+B cells. These observations showthat H.pylori canbeidentified infeline mucosal secretions, andthat alocalized IgAimmuneresponsedevelops ingastric tissue ofH.pylori-infected cats.Thefindings suggest a zoonotic risk fromexposuretopersonnel handling H.pylori-infected catsinvivaria.