Fecal and vaginal microbiota of vaccinated and non-vaccinated pregnant elk challenged with Brucella abortus

IntroductionBrucella abortus is the causative agent of brucellosis in cattle and in humans, resulting in economic losses in the agricultural sector and representing a major threat to public health. Elk populations in the American Northwest are reservoirs for this bacterium and transmit the agent to domestic cattle herds. One potential strategy to mitigate the transmission of brucellosis by elk is vaccination of elk populations against B. abortus; however, elk appear to be immunologically distinct from cattle in their responses to current vaccination strategies. The differences in host response to B. abortus between cattle and elk could be attributed to differences between the cattle and elk innate and adaptive immune responses. Because species-specific interactions between the host microbiome and the immune system are also known to affect immunity, we sought to investigate interactions between the elk microbiome and B. abortus infection and vaccination.MethodsWe analyzed the fecal and vaginal microbial communities of B. abortus-vaccinated and unvaccinated elk which were challenged with B. abortus during the periparturient period.ResultsWe observed that the elk fecal and vaginal microbiota are similar to those of other ruminants, and these microbial communities were affected both by time of sampling and by vaccination status. Notably, we observed that taxa representing ruminant reproductive tract pathogens tended to increase in abundance in the elk vaginal microbiome following parturition. Furthermore, many of these taxa differed significantly in abundance depending on vaccination status, indicating that vaccination against B. abortus affects the elk vaginal microbiota with potential implications for animal reproductive health.DiscussionThis study is the first to analyze the vaginal microbiota of any species of the genus Cervus and is also the first to assess the effects of B. abortus vaccination and challenge on the vaginal microbiome

Tardigrade community microbiomes in North American orchards include putative endosymbionts and plant pathogens

The microbiome of tardigrades, a phylum of microscopic animals best known for their ability to survive extreme conditions, is poorly studied worldwide and completely unknown in North America. An improved understanding of tardigrade-associated bacteria is particularly important because tardigrades have been shown to act as vectors of the plant pathogen Xanthomonas campestris in the laboratory. However, the potential role of tardigrades as reservoirs and vectors of phytopathogens has not been investigated further. This study analyzed the microbiota of tardigrades from six apple orchards in central Iowa, USA, and is the first analysis of the microbiota of North American tardigrades. It is also the first ever study of the tardigrade microbiome in an agricultural setting. We utilized 16S rRNA gene amplicon sequencing to characterize the tardigrade community microbiome across four contrasts: location, substrate type (moss or lichen), collection year, and tardigrades versus their substrate. Alpha diversity of the tardigrade community microbiome differed significantly by location and year of collection but not by substrate type. Our work also corroborated earlier findings, demonstrating that tardigrades harbor a distinct microbiota from their environment. We also identified tardigrade-associated taxa that belong to genera known to contain phytopathogens (Pseudomonas, Ralstonia, and the Pantoea/Erwinia complex). Finally, we observed members of the genera Rickettsia and Wolbachia in the tardigrade microbiome; because these are obligate intracellular genera, we consider these taxa to be putative endosymbionts of tardigrades. These results suggest the presence of putative endosymbionts and phytopathogens in the microbiota of wild tardigrades in North America.This is a preprint made available through bioRxiv at doi:10.1101/2022.01.28.478239. It is made available under a CC-BY-NC-ND 4.0 International license

FISHing for Rickettsia in tardigrades: additional evidence for tardigrade endosymbionts

Many ecdysozoans harbour endosymbiotic bacteria within their microbiota, and these endosymbionts can have a range of positive and negative effects on their hosts. Recent 16S rRNA gene amplicon sequencing studies have provided evidence for endosymbionts within the tardigrade microbiota. In a previous amplicon study, we determined that sequences corresponding to the endosymbiotic genus Rickettsia were significantly more associated with tardigrades than with the substrate from which they were isolated. Here, we performed fluorescence in situ hybridization (FISH) using a Rickettsia-specific probe, RickB1, to determine if Rickettsia could be found in tardigrades. RickB1 and a probe targeting most bacteria, EUB338, colocalized within tardigrade tissues, indicating the presence of Rickettsia. We also performed FISH using RickB1 and a nonsense probe, which allowed us to distinguish between false-positives and true positives. This method revealed RickB1 signals in tardigrades that were not due to erroneous probe binding, providing further evidence that Rickettsia is present in tardigrades. Future research will be necessary to determine the effects, if any, of these endosymbionts on their tardigrade hosts.This article is published as Bienvenido W Tibbs-Cortes and others, FISHing for Rickettsia in tardigrades: additional evidence for tardigrade endosymbionts, Zoological Journal of the Linnean Society, 2023;, zlad081, https://doi.org/10.1093/zoolinnean/zlad081. Posted with permission.This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited

Closed genome sequences of two Listeria monocytogenes ST121 strains

We performed Oxford Nanopore and Illumina sequencing to generate accurate, closed genomes for the Listeria monocytogenes strains 6179 and L58-55. The new assemblies were generally similar to the previous Illumina-based assemblies, but additional rRNA operons and repeat regions were identified in the new assembly for strain 6179.This article is published as Tibbs-Cortes, Bienvenido W., Dylan L. Schultz, and Stephan Schmitz-Esser. "Closed genome sequences of two Listeria monocytogenes ST121 strains." Microbiology Resource Announcements (2023): e00750-23. doi:https://doi.org/10.1128/MRA.00750-23. Copyright © 2023 Tibbs-Cortes et al. This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International license

Influence of the artificial sodium saccharin sweetener Sucram® on the rumen content and rumen epithelium microbiota in dairy cattle: A pilot study

The aim of this pilot study was to identify changes in both the rumen content and rumen epithelial microbiota in response to the supplementation of Sucram ® , a sodium-saccharin-based sweetener (Pancosma S.A./ADM Groups, Rolle, Switzerland). Rumen microbial communities are essential for animal growth and performance, and changes in these communities can have major effects on these parameters. Little or no research is available regarding how saccharin-based artificial sweeteners, fed to cattle in attempts to increase palatability and encourage feed intake, affect rumen microbial communities. The rumen epithelium and rumen content microbiota of five lactating Holstein-Friesian dairy cattle were compared before (baseline, BL) and after a 28-day supplementation of Sucram ® using Illumina MiSeq-based 16S rRNA gene sequencing. After supplementation of Sucram ® , significant changes in the abundance of specific taxa were detected: an increase in Prevotella and Sharpea species, a decrease in Treponema, Leptospiraceae, Ruminococcus and methanogenic archaea (pThis is an open-access article distributed under the terms of the Creative Commons Attribution License

Fecal and vaginal microbiota of vaccinated and non-vaccinated pregnant elk challenged with Brucella abortus

Introduction: Brucella abortus is the causative agent of brucellosis in cattle and in humans, resulting in economic losses in the agricultural sector and representing a major threat to public health. Elk populations in the American Northwest are reservoirs for this bacterium and transmit the agent to domestic cattle herds. One potential strategy to mitigate the transmission of brucellosis by elk is vaccination of elk populations against B. abortus; however, elk appear to be immunologically distinct from cattle in their responses to current vaccination strategies. The differences in host response to B. abortus between cattle and elk could be attributed to differences between the cattle and elk innate and adaptive immune responses. Because species-specific interactions between the host microbiome and the immune system are also known to affect immunity, we sought to investigate interactions between the elk microbiome and B. abortus infection and vaccination. Methods: We analyzed the fecal and vaginal microbial communities of B. abortus-vaccinated and unvaccinated elk which were challenged with B. abortus during the periparturient period. Results: We observed that the elk fecal and vaginal microbiota are similar to those of other ruminants, and these microbial communities were affected both by time of sampling and by vaccination status. Notably, we observed that taxa representing ruminant reproductive tract pathogens tended to increase in abundance in the elk vaginal microbiome following parturition. Furthermore, many of these taxa differed significantly in abundance depending on vaccination status, indicating that vaccination against B. abortus affects the elk vaginal microbiota with potential implications for animal reproductive health. Discussion: This study is the first to analyze the vaginal microbiota of any species of the genus Cervus and is also the first to assess the effects of B. abortus vaccination and challenge on the vaginal microbiome.This article is published as Tibbs-Cortes BW, Rahic-Seggerman FM, Schmitz-Esser S, Boggiatto P, Olsen S and Putz EJ (2024) Fecal and vaginal microbiota of vaccinated and non-vaccinated pregnant elk challenged with Brucella abortus. Front. Vet. Sci. 11:1334858. doi: 10.3389/fvets.2024.1334858. © 2024 Tibbs-Cortes, Rahic-Seggerman, Schmitz-Esser, Boggiatto, Olsen and Putz. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms

Influence of a sodium-saccharin sweetener on the rumen content and rumen epithelium microbiota in dairy cattle during heat stress

The effect of a saccharin-based artificial sweetener was tested on animal performance measures and on the microbial communities associated with the rumen content and with the rumen epithelium during heat stress. Ten cannulated Holstein-Friesian milking dairy cattle were supplemented with 2 grams of saccharin-based sweetener per day, top-dressed into individual feeders for a 7-day adaptation period followed by a 14-day heat stress period. A control group of ten additional cows subjected to the same environmental conditions but not supplemented with sweetener were included for comparison. 16S rRNA gene amplicon sequencing was performed on rumen content and rumen epithelium samples from all animals, and comparisons of rumen content microbiota and rumen epithelial microbiota were made between supplemented and control populations. Supplementation of the saccharin-based sweetener did not affect the rumen content microbiota, but differences in the rumen epithelial microbiota beta-diversity (PERMANOVA, P = 0.003, R 2 = 0.12) and alpha-diversity (Chao species richness, P = 0.06 and Shannon diversity, P = 0.034) were detected between the supplemented and control experimental groups. Despite the changes detected in the microbial community, animal performance metrics including feed intake, milk yield, and short-chain fatty acid (acetic, propionic, and butyric acid) concentrations were not different between experimental groups. Thus, under the conditions applied, supplementation with a saccharin-based sweetener does not appear to affect animal performance under heat stress. Additionally, we detected differences in the rumen epithelial microbiota due to heat stress when comparing initial, pre-stressed microbial communities to the communities after heat stress. Importantly, the changes occurring in the rumen epithelial microbiota may have implications on barrier integrity, oxygen scavenging, and urease activity. This research adds insight into the impact of saccharin-based sweeteners on the rumen microbiota and the responsivity of the rumen epithelial microbiota to different stimuli, providing novel hypotheses for future research.This is a pre-copyedited, author-produced version of an article accepted for publication in Journal of Animal Science following peer review. The version of record: Koester, Lucas R., Kris Hayman, Chiron J. Anderson, Bienvenido W. Tibbs-Cortes, Karrie M. Daniels, Faith M. Seggerman, Patrick J. Gorden, Mark Lyte, and Stephan Schmitz-Esser. "Influence of a sodium-saccharin sweetener on the rumen content and rumen epithelium microbiota in dairy cattle during heat stress." Journal of Animal Science (2022) is available online at DOI: 10.1093/jas/skac403. Copyright 2022 The Author(s). This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited. Posted with permission