Abstract
Helicobacter spp. are almost ubiquitously present in the stomach of dogs. Various Helicobacter species have been isolated, however, their identification by routine diagnostic methods is impossible, culture is cumbersome and not sensitive. We developed and validated a PCR assay based on amplification of the urease B gene for the detection of Helicobacter species in gastric biopsy specimens of dogs against a set of established invasive and non-invasive detection methods. Altogether, urease B gene PCR had a sensitivity of 98% identifying 59 of 60 infected dogs in a series of 65 dogs. Direct identification of helicobacters present in gastric biopsies was obtained by species-specific PCR based on the urease gene with a newly developed PCR for H. bizzozeronii/H. salomonis and in established PCR assays for H. felis and 'H. heilmannii'. In the 59 dogs positive by the urease B gene PCR the colonizing Helicobacter was identified by species specific PCR and/or culture as H. bizzozeronii/H. salomonis in nineteen, 'H. heilmannii' in twelve, H. felis in seven and a Helicobacter sp. in two; no identification was obtained in 31 dogs and a double infection was found in six dogs. Results of species-specific PCR were concordant with conventional and molecular identification of Helicobacter strains isolated in six culture positive dogs. These findings indicate that urease B gene PCR is accurate in diagnosing a helicobacteriosis in dogs, and that various Helicobacter species can reliably be identified by species specific urease PCR.