Helicobacter spp. infection in cats: evaluation of the humoral immune response and prevalence of gastric Helicobacter spp.

The principal aims of this study were to evaluate the humoral immune respon se (IgG) of cats with gastric Helicobacter spp. infection, and to determine the prevalence of different types of Helicobacter spp. in the stomachs of cats. The Helicobacter infection status of 45 cats (12 healthy spay/neuter cats, 9 sick cats, 24 colony cats) was determined by evaluating endoscopic gastric biopsies for urease activity, presence of Helicobacter-like organis ms (HLO) on histopathology, and genus and species-specific PCR. Serum sampl es were evaluated with a kinetic enzyme linked immunosorbent assay (ELISA) utilizing the high molecular cell-associated protein (HM-CAP) fraction of H . felis ATCC 49179. Seventeen of 45 cats were infected with Helicobacter spp.: "H. heilmannii" 9/17, H. felis 4/17, mixed "H. heilmannii" and H. felis 3/17, unclassified- Helicobacter spp. 7/17. H. pylori was not detected in any cat. Kinetic ELIS A results were significantly higher for infected cats, than for uninfected cats. Cats infected with different Helicobacter spp. showed similar distrib ution of OD/min values. There were no effects of age or clinical signs on t he results of kinetic ELISA. No correlation between colonization density an d seroconversion was observed. There were statistically significant, but we ak correlations between the degree of seroconversion and the degree of infl ammation, and the number of lymphoid follicles. Infected cats had more seve re inflammation in the pylorus and fundus than uninfected cats. Infected si ck cats had a higher degree of pyloric, but not fundic inflammation, than h ealthy infected cats and uninfected sick cats. The results indicate that naturally acquired infection with gastric Helicob acter spp. is associated with seroconversion (IgG) in cats. The similar ELI SA values in cats infected with a variety of Helicobacter spp. suggests sub stantial antigenic homology between different Helicabacter spp. The higher degree of inflammation in infected than uninfected cats, supports a role fo r Helicobacter as a cause of gastritis in cats. (C) 2001 Elsevier Science B .V. All rights reserved.