Characterization of the Vaginal Microbiota of Ewes and Cows Reveals a Unique Microbiota with Low Levels of Lactobacilli and Near-Neutral pH

Abstract

Although a number of common reproductive disorders in livestock involve bacterial infection, very little is known about their normal vaginal microbiota. Therefore, we sought to determine the species composition of sheep and cattle vaginal microbiota. Twenty Rambouillet ewes and twenty crossbred cows varying in age and reproductive status were sampled by ectocervicovaginal lavage. We amplified and sequenced the V3–V4 region of the 16S ribosomal RNA (rRNA) contents yielding a total of 907,667 high-quality reads. Good’s Coverage estimates indicated that we obtained data on 98 ± 0.01% of the total microbial genera present in each sample. Cow and ewe vaginal microbiota displayed few differences. Cow microbiota exhibited greater (P ≤ 0.05) α-diversity compared to the ewe microbiota. Both livestock species differed (P ≤ 0.05) from all previously reported vaginal communities. While bacteria were numerically dominant, Archaea were detected in 95% of cow and ewe samples, mainly of the order Desulfurococcales. Both ewes and cows were predominately colonized by the bacterial phyla Bacteroidetes, Fusobacteria, and Proteobacteria. The most abundant genera were Aggregatibacter spp., and Streptobacillus spp. Lactobacillus spp. were detected in 80% of ewe and 90% of cow samples, but only at very low abundances. Bacteria previously described from culture-based studies as common to the cow and ewe vaginal tract, except for Escherichia, were variably present, and only in low abundance. Ewe and cow pH differed (P ≤ 0.05), with means (±SD) of 6.7 ± 0.38 and 7.3 ± 0.63, respectively. In conclusion, 16S rRNA sequencing of cow and ewe vaginal ectocervicovaginal lavages showed that cow and ewe vaginal microbiota differ from culture-led results, revealing a microbiota distinct from previously described vaginal ecosystems.

Comparison of the Vaginal Cytological and Microbiological Results in the Detection of Normal Microflora of Pregnant

“…Vaginal microflora investigations in different reproductive periods acquired a 55.6% rate of bacterial growth in pregnant sheep. These results, Enterobacter species, Escherichia coli and Lactobacilli were the most isolated bacteria (Zaid, 2009). Swartz (2014 characterized vaginal microbiota of ewes and reported that Aggregatibacter spp.…”

“…Swartz (2014 characterized vaginal microbiota of ewes and reported that Aggregatibacter spp. and Streptobacillus spp were the most abundant agents (Swartz et al, 2014). In this study, we planned to determinate normal microbial flora in pregnant ewes based on vaginal cytology and microbiology.…”

Approved and novel strategies in diagnostics of rat bite fever and otherStreptobacillusinfections in humans and animals

“…51 Some other isolates formerly assigned to S. moniliformis exist, from which S. notomytis from a spinifex hopping mouse (Notomys alexis) and from black rats (Rattus rattus) and S. ratti from an asymptomatically colonized black rat were recently described. 52,53 Contrarily to Nolan et al, 54 various potentially novel Streptobacillus species and phylotypes consistent with operational taxonomic units have been identified in the last few years from Atlantic salmon 55 and microbiomes of digestive tracts in dolphins and sea lions, [56][57][58] upper respiratory tracts in cotton rats, 37 digestive tracts in dogs, 39,59,60 intestinal tract of a ducks, 61 genital tracts in livestock, 32 and skin and gut microbiomes in humans (Fig. 1).…”

“…4,13,[16][17][18][19][20][21][22] Recently, various publications suggest that Streptobacillus species might be far more common and distributed in the environment or as commensal microbiota than previously thought. 32,37,[59][60][61][62][63] It could recently be shown that the natural reservoir for the very rare cases of human S. hongkongensis infection known to date is indeed the human oropharynx à and presumably not an unidentified animal or environmental reservoir. 49 Despite a certain amount of annually published case reports, most of which have solely used 16S rRNA sequencing alone for definite diagnosis, there has not been much progress in the diagnosis of acute clinical cases of RBF in the last decades.…”

“…17,20 However, as these strains are physically not available, reports are not fully in congruence with the genotypic and phenotypic properties of S. moniliformis. Moreover, as recent studies have even found large quantities also in genital tracts from cows and ewes, 32 there is some doubt if streptobacilli in livestock are identical with the RBF organism. Anecdotally, streptobacilli have been described from exotic host species like gerbils and squirrels that were occasionally named "Streptothrix paraxeri cepapi" after Smith's bush squirrel (Paraxerus cepapi), [33][34][35] partially with involvement of human infection resembling RBF, 33,36 but these isolates have also not been stored.…”