Current state of knowledge: the canine gastrointestinal microbiome

2012 ◽  
Vol 13 (1) ◽  
pp. 78-88 ◽  
Author(s):  
Seema Hooda ◽  
Yasushi Minamoto ◽  
Jan S. Suchodolski ◽  
Kelly S. Swanson

AbstractGastrointestinal (GI) microbes have important roles in the nutritional, immunological, and physiologic processes of the host. Traditional cultivation techniques have revealed bacterial density ranges from 104to 105colony forming units (CFU)/g in the stomach, from 105to 107CFU/g in the small intestine, and from 109to 1011CFU/g in the colon of healthy dogs. As a small number of bacterial species can be grown and studied in culture, however, progress was limited until the recent emergence of DNA-based techniques. In recent years, DNA sequencing technology and bioinformatics have allowed for better phylogenetic and functional/metabolic characterization of the canine gut microbiome. Predominant phyla include Firmicutes, Bacteroidetes, Fusobacteria, Proteobacteria, and Actinobacteria. Studies using 16S ribosomal RNA (rRNA) gene pyrosequencing have demonstrated spatial differences along the GI tract and among microbes adhered to the GI mucosa compared to those in intestinal contents or feces. Similar to humans, GI microbiome dysbiosis is common in canine GI diseases such as chronic diarrhea and inflammatory bowel diseases. DNA-based assays have also identified key pathogens contributing to such conditions, including variousClostridium,Campylobacter,Salmonella, andEscherichiaspp. Moreover, nutritionists have applied DNA-based techniques to study the effects of dietary interventions such as dietary fiber, prebiotics, and probiotics on the canine GI microbiome and associated health indices. Despite recent advances in the field, the canine GI microbiome is far from being fully characterized and a deeper characterization of the phylogenetic and functional/metabolic capacity of the GI microbiome in health and disease is needed. This paper provides an overview of recent studies performed to characterize the canine GI microbiome.

Pathogens ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 396
Author(s):  
Ewa Sajnaga ◽  
Marcin Skowronek ◽  
Agnieszka Kalwasińska ◽  
Waldemar Kazimierczak ◽  
Karolina Ferenc ◽  
...  

This study focused on the potential relationships between midgut microbiota of the common cockchafer Melolontha melolontha larvae and their resistance to entomopathogenic nematodes (EPN) infection. We investigated the bacterial community associated with control and unsusceptible EPN-exposed insects through nanopore sequencing of the 16S rRNA gene. Firmicutes, Proteobacteria, Actinobacteria, and Bacteroidetes were the most abundant bacterial phyla within the complex and variable midgut microbiota of the wild M. melolontha larvae. The core microbiota was found to include 82 genera, which accounted for 3.4% of the total number of identified genera. The EPN-resistant larvae differed significantly from the control ones in the abundance of many genera belonging to the Actinomycetales, Rhizobiales, and Clostridiales orders. Additionally, the analysis of the microbiome networks revealed different sets of keystone midgut bacterial genera between these two groups of insects, indicating differences in the mutual interactions between bacteria. Finally, we detected Xenorhabdus and Photorhabdus as gut residents and various bacterial species exhibiting antagonistic activity against these entomopathogens. This study paves the way to further research aimed at unravelling the role of the host gut microbiota on the output of EPN infection, which may contribute to enhancement of the efficiency of nematodes used in eco-friendly pest management.


Author(s):  
Ajay S. Arya ◽  
Minh T. H. Hang ◽  
Mark A. Eiteman

Bacteria were isolated from wastewater and soil containing charred wood remnants based on their ability to use levoglucosan as a sole carbon source and on their levoglucosan dehydrogenase (LGDH) activity. On the basis of their 16S rRNA gene sequences, these bacteria represented diverse genera of Microbacterium, Paenibacillus , Shinella , and Klebsiella . Genomic sequencing of the isolates verified that two isolates represented novel species, Paenibacillus athensensis MEC069 T and Shinella sumterensis MEC087 T , while the remaining isolates were closely related to either Microbacterium lacusdiani or Klebsiella pneumoniae . The genetic sequence of LGDH, lgdA , was found in the genomes of these four isolates as well as Pseudarthrobacter phenanthrenivorans Sphe3. The identity of the P. phenanthrenivorans LGDH was experimentally verified following recombinant expression in E. coli . Comparison of the putative genes surrounding lgdA in the isolate genomes indicated that several other gene products facilitate the bacterial catabolism of levoglucosan, including a putative sugar isomerase and several transport proteins. Importance Levoglucosan is the most prevalent soluble carbohydrate remaining after high temperature pyrolysis of lignocellulosic biomass, but it is not fermented by typical production microbes such as Escherichia coli and Saccharomyces cerevisiae . A few fungi metabolize levoglucosan via the enzyme levoglucosan kinase, while several bacteria metabolize levoglucosan via levoglucosan dehydrogenase. This study describes the isolation and characterization of four bacterial species which degrade levoglucosan. Each isolate is shown to contain several genes within an operon involved in levoglucosan degradation, furthering our understanding of bacteria which metabolize levoglucosan.


2018 ◽  
Vol 17 (2) ◽  
pp. 105
Author(s):  
Agus Eko Prasetyo ◽  
Kikin Hamzah Mutaqin ◽  
Giyanto .

Characterization of phytoplasmas associated with coconut wilt disease in Derawan Island using in silico RFLP. Coconutwilt disease has been reported in Derawan Island that resulted in eradication up to 10% of the total cultivated palms. Theobjective of this study was to detect and characterize phytoplasmas associated with coconut wilt disease in Derawan islandusing nested PCR technique and in silico RFLP based on 16S rRNA gene sequences. Detection of phytoplasmas was performedusing nested PCR method, cloning of nPCR products, sequencing, and analysis of sequencing results using in silico RFLP.The results revealed that phytoplasmas could not be detected by PCR using P1/P7 primer pairs however it could be amplifiedby nested PCR using R16F2n/R16R2 primer pairs resulting amplicon at about 1.25 kb. In silico RFLP analysis indicated thatphytoplasmas associated with coconut wilt disease in Derawan Island belong to 16SrII (witches broom phytoplasma). PCRproduct of the nPCR need to be sequenced because the R16F2n/R16R2 primer will also amplify the other bacterial species, mainly from Gram positive bacteria.


2021 ◽  
Vol 12 ◽  
Author(s):  
Wenyi Xu ◽  
Tianda Chen ◽  
Yuwei Pei ◽  
Hao Guo ◽  
Zhuanyu Li ◽  
...  

Characterization of the bacterial composition and functional repertoires of microbiome samples is the most common application of metagenomics. Although deep whole-metagenome shotgun sequencing (WMS) provides high taxonomic resolution, it is generally cost-prohibitive for large longitudinal investigations. Until now, 16S rRNA gene amplicon sequencing (16S) has been the most widely used approach and usually cooperates with WMS to achieve cost-efficiency. However, the accuracy of 16S results and its consistency with WMS data have not been fully elaborated, especially by complicated microbiomes with defined compositional information. Here, we constructed two complex artificial microbiomes, which comprised more than 60 human gut bacterial species with even or varied abundance. Utilizing real fecal samples and mock communities, we provided solid evidence demonstrating that 16S results were of poor consistency with WMS data, and its accuracy was not satisfactory. In contrast, shallow whole-metagenome shotgun sequencing (shallow WMS, S-WMS) with a sequencing depth of 1 Gb provided outputs that highly resembled WMS data at both genus and species levels and presented much higher accuracy taxonomic assignments and functional predictions than 16S, thereby representing a better and cost-efficient alternative to 16S for large-scale microbiome studies.


2015 ◽  
Vol 61 (2) ◽  
pp. 90-94 ◽  
Author(s):  
Mor Nitzan ◽  
Sefi Mintzer ◽  
Hanah Margalit

The human microbiome is dynamic and unique to each individual, and its role is being increasingly recognized in healthy physiology and in disease, including gastrointestinal and neuropsychiatric disorders. Therefore, characterizing the human microbiome and the factors that shape its bacterial population, how they are related to host-specific attributes, and understanding the ways in which it can be manipulated and the phenotypic consequences of such manipulations are of great importance. Characterization of the microbiome so far has been mostly based on compositional studies alone, where relative abundances of different species are compared in different conditions, such as health and disease. However, inter-relationships among the bacterial species, such as competition and cooperation over metabolic resources, may be an important factor that affects the structure and function of the microbiome. Here we review the network-based approaches in answering such questions and explore the first attempts that focus on the interactions facet, complementing compositional studies, towards understanding the microbiome structure and its complex relationship with the human host.


2006 ◽  
Vol 72 (4) ◽  
pp. 2837-2848 ◽  
Author(s):  
Patricia I. Diaz ◽  
Natalia I. Chalmers ◽  
Alexander H. Rickard ◽  
Colin Kong ◽  
Craig L. Milburn ◽  
...  

ABSTRACT The initial microbial colonization of tooth surfaces is a repeatable and selective process, with certain bacterial species predominating in the nascent biofilm. Characterization of the initial microflora is the first step in understanding interactions among community members that shape ensuing biofilm development. Using molecular methods and a retrievable enamel chip model, we characterized the microbial diversity of early dental biofilms in three subjects. A total of 531 16S rRNA gene sequences were analyzed, and 97 distinct phylotypes were identified. Microbial community composition was shown to be statistically different among subjects. In all subjects, however, 4-h and 8-h communities were dominated by Streptococcus spp. belonging to the Streptococcus oralis/Streptococcus mitis group. Other frequently observed genera (comprising at least 5% of clone sequences in at least one of the six clone libraries) were Actinomyces, Gemella, Granulicatella, Neisseria, Prevotella, Rothia, and Veillonella. Fluorescence in situ hybridization (FISH) confirmed that the proportion of Streptococcus sp. sequences in the clone libraries coincided with the proportion of streptococcus probe-positive organisms on the chip. FISH also revealed that, in the undisturbed plaque, not only Streptococcus spp. but also the rarer Prevotella spp. were usually seen in small multigeneric clusters of cells. This study shows that the initial dental plaque community of each subject is unique in terms of diversity and composition. Repetitive and distinctive community composition within subjects suggests that the spatiotemporal interactions and ecological shifts that accompany biofilm maturation also occur in a subject-dependent manner.


2011 ◽  
Vol 78 (2) ◽  
pp. 511-518 ◽  
Author(s):  
Yohei Watanabe ◽  
Fumiko Nagai ◽  
Masami Morotomi

ABSTRACTIsolation, cultivation, and characterization of the intestinal microorganisms are important for understanding the comprehensive physiology of the human gastrointestinal (GI) tract microbiota. Here, we isolated two novel bacterial strains, YIT 12067Tand YIT 12068, from the feces of healthy human adults. Phylogenetic analysis indicated that they belonged to the same species and were most closely related toPhascolarctobacterium faeciumACM 3679T, with 91.4% to 91.5% 16S rRNA gene sequence similarities, respectively. Substrate availability tests revealed that the isolates used only succinate; they did not ferment any other short-chain fatty acids or carbohydrates tested. When these strains were cocultured with the xylan-utilizing and succinate-producing bacteriumParaprevotella xylaniphilaYIT 11841T, in medium supplemented with xylan but not succinate, their cell numbers became 2 to 3 orders of magnitude higher than those of the monoculture; succinate became undetectable, and propionate was formed. Database analysis revealed that over 200 uncultured bacterial clones from the feces of humans and other mammals showed high sequence identity (>98.7%) to YIT 12067T. Real-time PCR analysis also revealed that YIT 12067T-like bacteria were present in 21% of human fecal samples, at an average level of 3.34 × 108cells/g feces. These results indicate that YIT 12067T-like bacteria are distributed broadly in the GI tract as subdominant members that may adapt to the intestinal environment by specializing to utilize the succinate generated by other bacterial species. The phylogenetic and physiological properties of YIT 12067Tand YIT 12068 suggest that these strains represent a novel species, which we have designatedPhascolarctobacterium succinatutenssp. nov.


2018 ◽  
Vol 5 (10) ◽  
pp. 329-337
Author(s):  
Daniel Olusegun Diyaolu ◽  
Fatuyi Olanipekun Ekundayo ◽  
Emmanuel Adedayo Fasakin ◽  
Olabode Thomas Adebayo

This study aimed at identifying Lactobacillus plantarum from fermented maize, sorghum, soyabeans and cassava, using both phenotypic method and 16S RNA sequencing, as well as determining similarity or otherwise among recovered isolates. Biochemical characterization of isolates recovered from these fermented foods revealed that L. plantarum occurred in all fermented food examined, with slight variation in their abilities to ferment some sugars (arabinose, dulbitol and mannitol). These phenotypically identified isolates were also confirmed to be L. plantarum by 16S rRNA sequencing, having close relatedness (> 95%) with other isolates available in the gene bank. However, intragenomic heterogeneity of the 16S rRNA gene was observed among these L. plantarum isolates. The result obtained in this finding pinpoints the need to evaluate the beneficial effects each strain of L. plantarum may possess as promising probiotics, rather than generalising common effects for all strains of this bacterial species.


2016 ◽  
Vol 65 (3) ◽  
pp. 341-352 ◽  
Author(s):  
Wael S. El-Sayed

Anaerobic reductive dechlorination of 2,3-dichlorophenol (2,3DCP) and 2,4,6-trichlorophenol (2,4,6TCP) was investigated in microcosms from River Nile sediment. A stable sediment-free anaerobic microbial consortium reductively dechlorinating 2,3DCP and 2,4,6TCP was established. Defined sediment-free cultures showing stable dechlorination were restricted to ortho chlorine when enriched with hydrogen as the electron donor, acetate as the carbon source, and either 2,3-DCP or 2,4,6-TCP as electron acceptors. When acetate, formate, or pyruvate were used as electron donors, dechlorination activity was lost. Only lactate can replace dihydrogen as an electron donor. However, the dechlorination potential was decreased after successive transfers. To reveal chlororespiring species, the microbial community structure of chlorophenol-reductive dechlorinating enrichment cultures was analyzed by PCR-denaturing gradient gel electrophoresis (DGGE) of 16S rRNA gene fragments. Eight dominant bacteria were detected in the dechlorinating microcosms including members of the genera Citrobacter, Geobacter, Pseudomonas, Desulfitobacterium, Desulfovibrio, and Clostridium. Highly enriched dechlorinating cultures were dominated by four bacterial species belonging to the genera Pseudomonas, Desulfitobacterium, and Clostridium. Desulfitobacterium represented the major fraction in DGGE profiles indicating its importance in dechlorination activity, which was further confirmed by its absence resulting in complete loss of dechlorination. Reductive dechlorination was confirmed by the stoichiometric dechlorination of 2,3DCP and 2,4,6TCP to metabolites with less chloride groups and by the detection of chlorophenol RD cprA gene fragments in dechlorinating cultures. PCR amplified cprA gene fragments were cloned and sequenced and found to cluster with the cprA/pceA type genes of Dehalobacter restrictus.


Animals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 31
Author(s):  
Elisa Cotozzolo ◽  
Paola Cremonesi ◽  
Giulio Curone ◽  
Laura Menchetti ◽  
Federica Riva ◽  
...  

The microbiota is extremely important for the animal’s health, but, to date, knowledge on the intestinal microbiota of the rabbit is very limited. This study aimed to describe bacterial populations that inhabit the different gastrointestinal compartments of the rabbit: stomach, duodenum, jejunum, ileum, caecum, and colon. Samples of the luminal content from all compartments of 14 healthy New White Zealand rabbits were collected at slaughter and analyzed using next generation 16S rRNA Gene Sequencing. The findings uncovered considerable differences in the taxonomic levels among the regions of the digestive tract. Firmicutes were the most abundant phylum in all of the sections (45.9%), followed by Bacteroidetes in the large intestine (38.9%) and Euryarchaeota in the foregut (25.9%). Four clusters of bacterial populations were observed along the digestive system: (i) stomach, (ii) duodenum and jejunum, (iii) ileum, and (iv) large intestine. Caecum and colon showed the highest richness and diversity in bacterial species, while the highest variability was found in the upper digestive tract. Knowledge of the physiological microbiota of healthy rabbits could be important for preserving the health and welfare of the host as well as for finding strategies to manipulate the gut microbiota in order to also promote productive performance.


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