Helicobacter apri sp. nov., isolated from wild boars

Abstract

Three isolates (A19 T , C21 and F12) with spiral-shaped cells and one bipolar sheathed flagellum were obtained from gastric mucosa and caecal contents of three different wild boars (Sus scrofa) and subjected to a polyphasic taxonomic study. A genus-specific PCR showed that these isolates belonged to the genus Helicobacter. Phylogenetic analysis based on 16S rRNA, 60-kDa heat-shock protein (HSP60) and atpA genes demonstrated they formed a novel lineage within this genus. Pairwise 16S rRNA, HSP60 and atpA gene sequence comparisons of the three isolates revealed 99.7, 99.4 and 99.9 % similarity, respectively, among the three isolates; the 16S rRNA gene of isolate A19 T shared 98.5 % sequence similarity with its nearest validly named neighbouring species, Helicobacter mastomyrinus (to the type strain MIT 97-5577 T ). The taxonomic uniqueness of the wild boar isolates was confirmed by protein analysis performed by matrix-assisted laser desorption/ionization time-of-flight MS and by a distinctive biochemical profile. These data indicated that isolates A19 T , C21 and F12 represent a novel taxon, for which the name Helicobacter apri sp. nov. is proposed, with isolate A19 T (=DSM 28990 T =LMG 28471 T ) as the type strain.The genus Helicobacter was erected by Goodwin (1989) with the description of two species: Helicobacter pylori and Helicobacter mustelae. Vandamme et al. (1991) transferred two additional Campylobacter species to this novel genus as Helicobacter fennelliae and Helicobacter cinaedi. The genus has since expanded considerably and, at the time of writing (October 2015), comprises 36 species with validly published names (Jeon et al., 2015), including several species isolated from the stomach of pigs and other animals (Dewhirst et al., 1994;Moyaert et al., 2007;Baele et al., 2008;Smet et al., 2012). In the present study, three novel isolates from three different animals, two recovered from caecal contents (A19 T and F12) and one from stomach mucosa (C21) of wild boars, were submitted to a polyphasic taxonomic characterization.From January to September 2011, during a study of gastric and intestinal Epsilonproteobacteria of wild boars killed within a programme for reducing their density in the Apennine Mountains in Bologna Province (Italy), Helicobacter isolates were obtained from 16 of 21 animals. In all 16 animals, Helicobacter isolates were recovered from caecal contents and in four animals they were also isolated from gastric mucosa. Isolations were made after 4 days of incubation at 37±1 C in a microaerobic atmosphere, on nutrient sheep-blood agar using a filter method (Zanoni et al., 2007) and, at the same time, on nutrient sheep-blood agar [Nutrient Broth No. 2 (Oxoid) with 1.5 % Bacto Agar (Difco) and 10 % sheep blood] plus Skirrow and Blaser Wang selective supplement (Oxoid). Agar plates were never more than 3-4Abbreviations: BI, Bayesian inference; MALDI-TOF, matrix-assisted laser desorption/ionization time-of-flight; ML, maximum-likelihood.

Evidence for a primate origin of zoonotic Helicobacter suis colonizing domesticated pigs

“…This further supports our theory of a fairly recent host jump of H. suis to pigs from macaques or other unknown hosts, although further research should be performed in additional wild boar populations around the globe to provide more insights. Recently, a novel Helicobacter species, H. apri, has been described in wild boars, but this is an enterohepatic Helicobacter species that does not produce urease (Zanoni et al, 2016). It was, therefore, not included in our study.…”

Other Helicobacters, gastric and gut microbiota

“…Another novel urease‐negative Helicobacter species, “ Helicobacter apri” sp. nov., was isolated from the stomach and cecal contents of wild boars living in the Apennine Mountains . “ Helicobacter canicola” sp.…”

“…nov., was isolated from the stomach and cecal contents of wild boars living in the Apennine Mountains. 3 "Helicobacter canicola" sp. nov., isolated from canine feces, was previously misidentified as Helicobacter cinaedi.…”

Helicobacter labacensis sp. nov., Helicobacter mehlei sp. nov., and Helicobacter vulpis sp. nov., isolated from gastric mucosa of red foxes (Vulpes vulpes)

“…The discriminating characteristics are presented in , where they are compared to data from other gastric helicobacters, as listed in the study by Zanoni et al . [33]. The fox isolates differed from other gastric Helicobacter in their sensitivity to nalidixic acid and cephalotin (sensitive to both).…”