Histological and Immunohistochemical Detection of DifferentHelicobacterSpecies in the Gastric Mucosa of Cats

Abstract

Abstract. Detailed histopathological evaluation of the gastric mucosa of Helicobacter-infected cats is complicated by the difficulty of recognizing Helicobacter organisms on hematoxylin and eosin (HE)-stained sections and the ability of multiple Helicobacter species to infect cats. In this study, the presence and localization of different species of Helicobacter in the stomachs of cats was investigated using silver staining and immunohistochemistry. Five groups containing 5 cats each were established (group 1: urease negative and Helicobacter free; groups 2, 3, 4, and 5: urease positive and infected with Helicobacter heilmannii, unclassified Helicobacter spp., Helicobacter felis, and Helicobacter pylori, respectively). Gastric samples were evaluated by HE and silver staining and by immunohistochemistry with 3 different anti-Helicobacter primary antibodies. Helicobacter were detected by Steiner stain in all infected cats at the mucosal surface, in the lumen of gastric glands, and in the cytoplasm of parietal cells. In silver-stained sections, H. pylori was easily differentiated from H. felis, H. heilmannii, and unclassified Helicobacter spp., which were larger and more tightly coiled. No organisms were seen in uninfected cats. Helicobacter antigen paralleled the distribution of organisms observed in Steinerstained sections for 2 of the 3 primary antibodies tested. The antisera were not able to discriminate between the different Helicobacter species examined. A small amount of Helicobacter antigen was present in the lamina propria of 3 H. pylori-, 3 H. felis-, and 1 H. heilmannii-infected cat. Minimal mononuclear inflammation was present in uninfected cats and in those infected with unclassified Helicobacter spp. and H. heilmannii cats. In H. felis-infected cats, lymphoid follicular hyperplasia with mild pangastric mononuclear inflammation and eosinophilic infiltrates were present. The H. pylori-infected cats had severe lymphoid follicular hyperplasia and mild to moderate mononuclear inflammation accompanied by the presence of neutrophils and eosinophils. These findings indicate that Steiner staining and immunohistochemistry are useful for detecting Helicobacter infections, particularly when different Helicobacter species can be present. Monoclonal antibodies specific for the different Helicobacter species could be important diagnostic aids. There appear to be differences in the severity of gastritis in cats infected with different Helicobacter species.Gastric spiral-shaped bacteria of the genus Helicobacter have been described in many animal species as well as in humans. 24,81 Although their presence has been documented since the end of the 19th century, it is only since the discovery of Helicobacter pylori in humans by Warren and Marshall in 1983 that much interest has been expressed in gastric Helicobacter in animals. 5,74,77,87 Helicobacter pylori infection in humans has been associated with chronic active gastritis, peptic ulcer, gastric mucosa-associated lymphoid tissue lymphoma, and adenocarcinoma. 10,20,30...

PCR detection of clarithromycin-susceptible and -resistant Helicobacter pylori from formalin-fixed, paraffin-embedded gastric biopsies

“…15 The failure of amplification in these cases may also be because of the lack of adequate numbers of organism in the sections used for PCR analysis. Alternatively, immunohistochemical methods are known to cross react with other Helicobacter species, 16,17 and these findings may represent infection with Helicobacter organisms other than H. pylori. The primer and probe combinations used in this study have been previously shown to be specific for H. pylori, 12 which raises the possibility of false-positive immunohistochemistry results due to cross reactivity with an expected lack of detection by PCR.…”

Study on the role of gastric Helicobacter infection in gross pathological and histological lesions of the stomach in finishing pigs

“…This antibody was shown to detect H. suis, H. heilmanni and H. felis (De Groote et al, 2000;Scanziani et al, 2001). As control, an additional section was incubated in a similar manner with an irrelevant rabbit serum.…”

Gastric Helicobacters in Domestic Animals and Nonhuman Primates and Their Significance for Human Health

“…However, follicular organization of the inflammatory cells was restricted to the infected animals (193,204).…”