Phylogeny of Helicobacter Isolates from Bird and Swine Feces and Description of Helicobacter pametensis sp. nov.

Abstract

Previously, nine fecal isolates from wild birds and a domestic swine were identified as helicobacters by phenotypic characterization and reaction with a helicobacter genus-specific DNA probe. These isolates fell into three biotypes by analysis of phenotypic traits. To further characterize these isolates, full 16s rRNA sequences were determined for strains representing each biotype, and sequence comparison indicated that the strains represented three novel, phylogenetically defined Helicobucter species. Three 16s rRNA-based DNA probes were designed and used to identify the remaining strains. Probe reactivity divided the strains into the same three groups identified phenotypically. Six of the isolates represented a new species of the genus Helicobucter for which we propose the name Helicobacter pumetensis sp. nov. The following phenotypic features distinguished H. pametensis from other Helicobucter and Cumpylobucter species: positive tests for oxidase, catalase, alkaline phosphatase, nitrate reduction, growth at 42"C, and growth in the presence of 1% glycine; negative tests for urease, gamma glutamyl transpeptidase, indoxyl acetate hydrolysis, and hippurate hydrolysis; and susceptibility to nalidixic acid and cephalothin. H. pametensis cells were motile and possessed one subterminal sheathed flagellum at each end. The two additional Helicobucter species were similar to H. pametensis except that they were urease positive, hydrolyzed indoxyl acetate, and were resistant to cephalothin. Because these two additional species are phenotypically similar and are represented by only two isolates for one species and one isolate for the other, they are not formally named but are referred to as Helicobucter sp. "Bird-B" and Helicobucter sp. "Bird-C." These three new Helicobacter species can easily be confused with Cumpylobucter coli, Cumpylobucter luri, and Cumpylobucter jejuni if only a limited number of phenotypic traits are used for identification. Since it is now known that birds can harbor Helicobacter as well as Cumpybbucter species, methods which clearly distinguish these genera should be used to identify bird campylobacter-like isolates or bacterial strains traceable to bird fecal contamination. The zoonotic potential of these new Helicobucter species should be examined.

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Identification of carboxylation enzymes and characterization of a novel four-subunit pyruvate:flavodoxin oxidoreductase from Helicobacter pylori

“…To date, eleven Helicobacter species have been isolated from a range of mammals (15,20,32). The organism is now accepted as the etiological agent for type B gastritis, and extensive evidence suggests a link with duodenal and gastric ulcer diseases (17,21,25,47,52).…”

Helicobacter trogontum sp. nov., Isolated from the Rat Intestine

“…In summary, the genus Helicobacter now includes not only gastric bacteria, as first hypothesized (16,18), but also intestinal colonizers (3,5,8,9,18,27,28,32). Studies of the hostparasite relationship of intestinal helicobacters, of natural and experimental infections, and of the conditions under which the intestinal helicobacters can induce disease are important for uinderstanding how H. pylon causes peptic ulcer disease as well as gastric cancer.…”