Detection of Helicobacter spp. DNA in the colonic biopsies of stray dogs: molecular and histopathological investigations
1 Department of Small Animal Internal Medicine, Resident of Specialized Veterinary Sciences, Science and Research Branch, Islamic Azad University (IAU), NO.14, Corner of Parvaz 1, Payam Blvd., Saadat Abad, Tehran, Iran
2 Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
3 Department of Microbiology, Faculty of Veterinary Medicine, University of Karaj, Karaj, Iran
4 Department of Pathology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
Diagnostic Pathology 2014, 9:50 doi:10.1186/1746-1596-9-50Published: 6 March 2014
In dogs, the gastric Helicobacter spp. have been well studied, but there is little information regarding the other parts of the alimentary system. The incidence of Helicobacter spp. infection in dogs is largely unknown and to our knowledge there are no data about their potential pathogenic role. In light of these considerations, the aims of this study were (i) to assess the prevalence of Helicobacter spp. in colonic biopsies of healthy and symptomatic stray dogs also (ii) we isolate and characterize helicobacters in canine colonic biopsies to compare the commonly used tests for the identification of Helicobacter spp. and to determine the occurrence of these species in dogs.
Tissues from fifteen stray dogs (8 males and 7 females, age 6 months –10 years) were used in this study. From each stray dog, multiple colonic biopsies were taken for PCR. Biopsies for PCR of cecum and colon were immediately frozen and stored at -20°C until DNA extraction. Samples for histological examination were fixed in 10% neutral buffered formalin and embedded in paraffin wax.
In the cecum and colon, Helicobacter spp. DNA was detected in all dogs. H.canis, H.bizzozeronii, H. bilis, H.felis, H.salomonis and H.pylori Identified by specific polymerase chain reaction. Histopathology demonstrated that Helicobacter organisms were localized within the surface mucus and the intestinal crypts. Dogs with heavy Helicobacter spp. colonization were significantly in younger as well as had a higher level of mucosal fibrosis/atrophy than dogs with uncolonized or poorly colonized biopsies (p < 0.05).
We have indicated that the crypts of the cecum and colon of healthy and symptomatic dogs are heavily colonized by Helicobacter spp.. Combined molecular and histological approaches demonstrated that enterohepatic Helicobacter spp. infection is rather common in colonic biopsies of healthy and symptomatic stray dogs, with Helicobacter spp. specialy H. canis, H.bizzozeroni, H.billis, H.felis and H. salomonis identified as the most common species.
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