Detection of Helicobacter-like DNA in the gastric mucosa of Thoroughbred horses

AIMS: To assess the presence of Helicobacter DNA in the gastric mucosa Thoroughbred horses. METHODS AND RESULTS: Squamous and glandular mucosa samples were collected from 20 Thoroughbreds. None of these horses had shown any clinical symptoms of gastrointestinal disease. Necropsy tissues were analysed using histopathological techniques and a Helicobacter genus-specific PCR assay followed by sequencing of the amplicons. Seven horses were diagnosed with gastric ulceration, five with gastritis and six with both pathologies. Only two horses had a healthy gastric mucosa. Helicobacter-like DNA was detected in two out of seven horses with gastric ulcers, three out of five horses with gastritis, five out of six horses with both pathologies and one horse with normal gastric mucosa. The sequences of 1195 and 1237 bp fragments of the 16S rRNA gene shared 99% identity with the Helicobacter pylori 16S rRNA gene. However, all the samples were negative when tested with H. pylori-specific PCR assays targeting the cagA and glmM genes. CONCLUSIONS: The Helicobacter genus might colonize the gastric mucosa of horses. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first report of Helicobacter-like DNA in the gastric mucosa of horses and the pathogenic potential of these organisms requires further investigation.