Background.
Helicobacter felis, an organism naturally infecting both canine and feline gastric mucosa, has been largely used as in animal models to study the ecology and treatment of human ...Helicobacter pylori infections. H. felis has not yet been studied at the genetic level.
Methods.
The aims of this study were to modify an in situ DNA isolation method suitable for H. felis and, by the use of pulsed‐field gel electrophoresis (PFGE), plasmid profiling, and ribotyping, to determine the degree of genetic variation among H. felis strains isolated from cats and dogs from various geographic locations, and to determine the genome size of H. felis. Furthermore, the ability of these new H. felis strains to colonize mice was tested.
Results.
Most H. felis strains were distinguishable from each other, and 20 distinct PFGE types were detected. Four pairs of strains within a country and animal species produced identical patterns. All strains tested were found to carry several plasmids and plasmid profiling was equally discriminatory to PFGE. Ribotyping was not able to discriminate all the strains.
Conclusions.
The genome size of H. felis was found to be ≈ 1.6 Mb.
During a study of the prevalence and distribution of gastric helicobacters in domestic pets, a novel group of Helicobacter-like organisms were identified. These "Helicobacter group 2" strains were ...initially distinguished from the species Helicobacter felis and Helicobacter bizzozeronii by their cellular morphology and the type of motility exhibited. Bacterial cells were only slightly spiral, 5 to 7 microns long, and 0.8 to 1.2 microns wide and showed an unusual slow wavelike motion. Each cell had tufts of sheathed flagella at one or both ends. Phylogenetic analysis by 16S ribosomal DNA sequence comparison revealed that H. felis, H. bizzozeronii, "Gastrospirillum hominis" 2, and the new group of helicobacters formed a distinct cluster with intraspecies similarity values of more than 98%. These taxa were clearly separated from all other known Helicobacter species. Dot blot DNA-DNA hybridization studies indicated that the Helicobacter group 2 strains are genetically homogeneous and distinct from other canine and feline gastric helicobacters. Quantitative DNA-DNA hybridization experiments showed that Helicobacter group 2 strains exhibit > 90% DNA homology to each other, but < 39% homology to the phylogenetically related taxa H. felis and H. bizzozeronii. We propose the name Helicobacter salomonis for the novel Helicobacter group 2 strains. The type strain is H. salomonis Inkinen (= CCUG 37845).
We describe the first verified domestic HEV case in a previously healthy 53-year-old man who presented a three-day history of upper stomach pain, nausea, fever, arthralgia and fatigue. At the first ...phase laboratory tests revealed high levels of AST and ALT and at the second phase high levels of bilirubin. Serum was positive for anti-HEV IgM and for HEV RNA confirming the diagnosis of acute hepatitis E. The HEV was genotype 3. Jaundice resolved in three months. In nonendemic areas autochthonous hepatitis E is more common than previously recognized and is possible in patients with acute hepatitis.
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