Microbiota in Health and Disease (Jul 2020)

Helicobacter pylori infection in shepherds, sheep and sheep-dogs

  • M. Dore,
  • G. Pes,
  • G. Sanna,
  • A. Sepulveda,
  • D. Graham

DOI
https://doi.org/10.26355/mhd_20207_306
Journal volume & issue
Vol. 2

Abstract

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Objectives: Previous studies demonstrated a high prevalence of Helicobacter pylori infection among shepherds, sheep, sheep raw milk and children having contact with sheep, suggesting a model of transmission of infection at elevated frequency. The aim of this study was to examine whether H. pylori infection may be present in sheep-dogs. Material and Methods: Stool, serum, and wool were collected from sheep and sheep-dogs belonging to different flocks chosen because the shepherds had documented (13C-UBT) H. pylori infection. H. pylori status in the animals was evaluated using a homemade anti-H. pylori IgG enzyme-linked immunosorbent assay (ELISA) for sheep and sheep-dogs. Stool samples from sheep and sheep-dogs were also analyzed using the stool antigen test (HpSA) developed for humans. Results were expressed as optical density (OD450). PCR amplification was performed using primers specific for H. pylori [cagA, vacA (s and m region), iceA, babA2] as well as primers specific for Helicobacter species (16S rRNA) from the DNA extracted from sheep wool wash surrounding the mammalian glands. Results: 58 animals were studied (44 sheep, 8 lambs and 6 sheep-dogs). The H. pylori antigen test was positive in 82% (36/44) and in 100% of sheep and sheep-dogs stool samples, respectively. Lamb stool samples were weakly positive. High anti H. pylori IgG serum levels were detected in all 6 sheep-dogs and in 42 of 44 sheep. Genomic H. pylori and Helicobacter species DNA was not detected from any of the sheep wool samples collected. Conclusions: Although cross-reactivity cannot be excluded, the presence of the H. pylori antigen in stools obtained from sheep and from sheep-dogs, and the strong positivity for anti H. pylori IgG in both coupled with the ability to isolate H. pylori from sheep milk and stomachs, suggest that interaction between species may enhance the spread of bacteria in heavily contaminated settings.

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