scholarly journals Synergistic interaction of hyposalinity stress with Vibrio infection causes mass mortalities in oysters by inducing host microflora imbalance and immune dysregulation

2021 ◽  
Author(s):  
Shikai Liu ◽  
Xin Li ◽  
Ben Yang ◽  
Chenyu Shi ◽  
Hebing Wang ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Transcriptome Profiling ◽  
Immune Dysregulation ◽  
Synergistic Interaction ◽  
Microbial Composition ◽  
Significant Information ◽  
Extreme Precipitation Events ◽  
Community Profiling ◽  
Apoptosis And Inflammation ◽  
Mass Mortalities

A sudden drop in salinity following extreme precipitation events usually causes mass mortalities of oysters exposed to pathogens in ocean environment. While how hyposalinity stress interacts with pathogens to cause mass mortality remains obscure. In this study, we performed an experiment by mimicking hyposalinity stress and pathogen infection with V. alginolyticus to investigate their synergistic effect on the mortality of infected oysters toward understanding of the interaction among environment, host, and pathogen. We showed that hyposalinity stress (10‰, 20‰ versus 30‰) did not significantly affect proliferation and virulence of V. alginolyticus, but significantly altered microbial composition and diversity in infected oysters. Microbial community profiling by 16S rRNA sequencing revealed disrupted homeostasis of digestive bacterial microbiota with increased abundance of several pathogenic bacteria, which may affect the pathogenesis in oysters. Transcriptome profiling of infected oysters revealed that a large number of genes associated with apoptosis and inflammation were significantly induced under hyposalinity, suggesting that hyposalinity stress may have triggered immune dysregulation in infected oysters. This work provides significant information in decoding mechanisms of synergistic interaction among environment factors, host genetics, and digestive microbiota, and how they contribute to pathogenesis.

Periodontopathogens: a new view. Systematic review. Part 2

2020 ◽  
Vol 20 (2) ◽  
pp. 160-167
Author(s):  
E. S. Slazhneva ◽  
E. A. Tikhomirova ◽  
V. G. Atrushkevich
Keyword(s):  
Systematic Review ◽  
Periodontal Disease ◽  
Pathogenic Bacteria ◽  
Periodontal Diseases ◽  
Oral Microbiome ◽  
Controlled Trials ◽  
New Paradigm ◽  
Microbial Composition ◽  
Randomized Controlled ◽  
The Past

Relevance. The modern view of periodontitis as a dysbiotic disease that occurs as a result of changes in the microbial composition of the subgingival region is considered in a systematic review.Purpose. To study a new paradigm of development of generalized periodontitis.Materials and methods. Randomized controlled trials (RCTS) were selected for the study, including cluster RCTS, controlled (non-randomized) microbiological and clinical studies of the oral microbiome in adult patients with generalized periodontitis over the past 10 years.Results. The transition from a symbiotic microflora to a dysbiotic pathogenic community triggers the host's inflammatory response, which contributes to the development of periodontal diseases. Modern ideas about periodontal pathogenic bacteria dictate new requirements for the treatment of periodontal diseases. The second part of the review examines the microbial profiles of periodontal disease in various nosological forms, the mechanisms of the immune response and approaches to the treatment of periodontal disease from the perspective of biofilm infection.Conclusions. As follows from modern literature periodontitis is to a certain extent caused by the transition from a harmonious symbiotic bacterial community to a dysbiotic one. Recent scientific studies have shown that not single microorganism is not able to cause disease but the microbial community as a whole leads to the development of pathology.

scholarly journals Community-Acquired Pneumonia in Children: Myths and Facts

2019 ◽  
Vol 36 (S 02) ◽  
pp. S54-S57 ◽  
Author(s):  
Ki Wook Yun ◽  
Rebecca Wallihan ◽  
Alexis Juergensen ◽  
Asuncion Mejias ◽  
Octavio Ramilo
Keyword(s):  
Respiratory Tract ◽  
Bacterial Infections ◽  
Pathogenic Bacteria ◽  
Bacterial Pathogen ◽  
Transcriptome Profiling ◽  
Antibiotic Use ◽  
Respiratory Viruses ◽  
Community Acquired Pneumonia ◽  
Prognostic Indicators ◽  
Upper Respiratory Tract

AbstractCommunity-acquired pneumonia (CAP) is the leading cause of death in children < 5 years of age worldwide. It is also one of the most frequent infectious diseases in children, leading to large antibiotic use and hospitalization even in the industrialized countries. However, the optimal management of CAP in children is still not well defined. Currently, respiratory viruses are considered the most frequent etiologic agents, but detection of viruses in the upper respiratory tract does not guarantee causation of pneumonia, nor precludes the presence of a bacterial pathogen. In both the upper and lower respiratory tract, respiratory viruses and pathogenic bacteria interact. Emerging evidence indicates that dual viral–bacterial infections function synergistically in many cases and together likely enhance the severity of CAP. Therefore, new and advanced technologies capable of sensitively and specifically discriminating viral, bacterial, and viral–bacterial coinfections are needed. Instead of focusing on the pathogen, analysis of host immune transcriptome profiles from children with CAP can potentially offer diagnostic signatures, help to assess disease severity, and eventually, prognostic indicators. An optimized management strategy by using molecular pathogen testing and transcriptome profiling will facilitate prompt, more appropriate, and targeted therapies, which in turn will lead to improved clinical outcomes in children with CAP.

Diets supplemented with chickpea or its main oligosaccharide component raffinose modify faecal microbial composition in healthy adults

2010 ◽  
Vol 1 (2) ◽  
pp. 197-207 ◽  
Author(s):  
W. Fernando ◽  
J. Hill ◽  
G. Zello ◽  
R. Tyler ◽  
W. Dahl ◽  
...  
Keyword(s):  
16S Rrna ◽  
Pathogenic Bacteria ◽  
Control Diet ◽  
Rflp Analysis ◽  
Healthy Adults ◽  
Rrna Gene ◽  
Microbial Composition ◽  
Clone Libraries ◽  
Bacterial Populations ◽  
Significant Difference

The effects of diets supplemented with either chickpea or its main oligosaccharide raffinose on the composition of the faecal microbial community were examined in 12 healthy adults (18-65 years) in a randomised crossover intervention study. Subjects consumed their usual diet supplemented with soups and desserts that were unfortified, or fortified with either 200 g/d of canned chickpeas or 5 g/d of raffinose for 3 week periods. Changes in faecal bacterial populations of subjects were examined using 16S rRNA-based terminal restriction fragment length polymorphisms (T-RFLP) and clone libraries generated from the diet pools. Classification of the clone libraries and T-RFLP analysis revealed that Faecalibacterium prausnitzii, reported to be an efficient butyrate producer and a highly metabolically active bacterium in the human intestinal microbiota, was more abundant in the raffinose diet and the chickpea diet compared to the control diet. However, no significant difference was observed in the faecal total short chain fatty acid concentration or in the levels of the components (butyrate, acetate and propionate) with the chickpea diet or the raffinose diet compared to the control diet. Bifidobacterium species were detected by T-RFLP in all three diet groups and quantitative real-time PCR (qPCR) analysis showed a marginal increase in 16S rRNA gene copies of Bifidobacterium with the raffinose diet compared to control (P>0.05). The number of individuals showing TRFs for the Clostridium histolyticum - Clostridum lituseburense groups, which include pathogenic bacteria species and putrefactive bacteria, were lower in the chickpea diet compared to the other two treatments. Diet appeared to affect colonisation by a high ammonia-producing bacterial isolate which was detected in 83%, 92% and 42% of individuals in the control, raffinose and chickpea groups, respectively. Our results indicate that chickpea and raffinose have the potential to modulate the intestinal microbial composition to promote intestinal health in humans.

scholarly journals Seasonal resistome diversity and dissemination of WHO priority antibiotic-resistant pathogens in Lebanese estuaries

2021 ◽  
Author(s):  
Wadad Hobeika ◽  
Margaux Gaschet ◽  
Marie-Cecile Ploy ◽  
Elena Buelow ◽  
Dolla Karam Sarkis ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Pathogenic Bacteria ◽  
Anthropogenic Activities ◽  
Resistant Bacteria ◽  
Anthropogenic Pressure ◽  
Significant Information ◽  
Antibiotic Resistant ◽  
Culture Techniques ◽  
Antimicrobial Resistance Genes ◽  
Key Drivers

Anthropogenic activities are demonstrated to be the key drivers of antimicrobial resistance (AMR) dissemination in the environment. Lebanese rivers that lead to the Mediterranean Sea were sampled at estuaries sites, under high anthropogenic pressure, in spring 2017 and winter 2018 to study seasonal variation of antimicrobial-resistant bacteria (ARBs) and antimicrobial resistance genes (ARGs). Methods: A combined approach using culture techniques and high throughput qPCR identified hotspots for antimicrobial resistance and anthropogenic pressure in particular locations along the Lebanese coast. Results: Multi-resistant Gram-negative (Enterobacterales and Pseudomonas spp) and Gram-positive bacterial pathogens were isolated. A high abundance of certain ARGs (vanB, blaBIC-1, blaGES, tetM, and mcr-1) was detected in 5 Lebanese estuaries. The relative abundance of ARGs was highest in winter and areas with high anthropogenic activities and population growth with an influx of refugees. Conclusion: Qualitative analysis of ARB and the analysis of the Lebanese estuaries resistome revealed critical levels of contamination with pathogenic bacteria and provided significant information about the spread of ARGs in anthropogenically impacted estuaries.

scholarly journals 370 Awardee Talk: Role of feed enzymes in gut health and function

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 111-112
Author(s):  
Charles Martin Nyachoti
Keyword(s):  
Pathogenic Bacteria ◽  
Production Systems ◽  
Nutrient Utilization ◽  
Gut Health ◽  
Microbial Composition ◽  
Medication Costs ◽  
Feed Enzymes ◽  
Enzyme Supplementation ◽  
And Function

Abstract Exogenous enzymes are routinely added to diets for non-ruminant animals, mainly to help enhance energy and nutrient utilization, thus contributing to efficient and sustainable production systems. Also, feed enzymes allow for effective utilization of non-traditional feedstuffs (e.g. co-products) in non-ruminant diets, with potential to mitigate feed cost. In addition to increased nutrient utilization, however, feed enzymes, through their impact on the gastrointestinal environment and microbial composition, can have a profound effect on indices of gut health and function. These effects may explain the reported reductions in medication costs and variability in animal performance and mortality rates observed with dietary enzyme supplementation. By acting on their target substrates, feed enzymes reduce the availability of non-digested substrates and in the case of carbohydrate-degrading enzymes can produce short-chain oligosaccharides with potential prebiotic effects. These changes are known to modulate the gut microbiome in favor of bacteria associated with a healthy gut, while reducing the population of pathogenic bacteria, which explains the reduced incidences of diarrhea that have been attributed to enzyme supplementation. Also, feed enzymes may reduce oxidative stress and enhance the functional capacity (e.g. maintaining barrier function) of the gastrointestinal tract. Feed enzymes by themselves may never be a single solution to mitigate gut health challenges in livestock production systems, but clearly there is a mounting body of evidence to support the role of feed enzymes in this regard. Therefore, their benefits will be maximized when used as part of an integrated solution approach for containing enteric pathogens of economic importance and eliminating the negative effects of dietary components with potential to compromise intestinal integrity.

scholarly journals Microbial communities in hummingbird feeders are distinct from floral nectar and influenced by bird visitation

2019 ◽  
Vol 286 (1898) ◽  
pp. 20182295 ◽  
Author(s):  
Casie Lee ◽  
Lisa A. Tell ◽  
Tiffany Hilfer ◽  
Rachel L. Vannette
Keyword(s):  
Microbial Communities ◽  
Pathogenic Bacteria ◽  
Sucrose Solution ◽  
Microbial Populations ◽  
Floral Nectar ◽  
Solution Ph ◽  
Microbial Composition ◽  
Ascomycete Fungi ◽  
Bacteria And Fungi ◽  
Free Ranging

Human provisioning can shape resource availability for wildlife, but consequences for microbiota availability and exchange remain relatively unexplored. Here, we characterized microbial communities on bills and faecal material of hummingbirds and their food resources, including feeders and floral nectar. We experimentally manipulated bird visitation to feeders and examined effects on sucrose solution microbial communities. Birds, feeders and flowers hosted distinct bacterial and fungal communities. Proteobacteria comprised over 80% of nectar bacteria but feeder solutions contained a high relative abundance of Proteobacteria, Firmicutes and Actinobacteria. Hummingbirds hosted bacterial taxa commonly found in other birds and novel genera including Zymobacter [Proteobacteria] and Ascomycete fungi. For feeders, bird-visited and unvisited solutions both accumulated abundant microbial populations that changed solution pH, but microbial composition was largely determined by visitation treatment. Our results reveal that feeders host abundant microbial populations, including some bird-associated microbial taxa. Microbial taxa in feeders were primarily non-pathogenic bacteria and fungi but differed substantially from those in floral nectar. These results demonstrate that human provisioning influences microbial intake by free-ranging hummingbirds; however, it is unknown how these changes impact hummingbird gastrointestinal flora or health.

Selective enrichment of commensal gut bacteria protects againstCitrobacter rodentium-induced colitis

2015 ◽  
Vol 309 (3) ◽  
pp. G181-G192 ◽  
Author(s):  
Linda Vong ◽  
Lee J. Pinnell ◽  
Pekka Määttänen ◽  
C. William Yeung ◽  
Eberhard Lurz ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Intestinal Barrier ◽  
Gut Bacteria ◽  
Enterohemorrhagic Escherichia Coli ◽  
Host Immune System ◽  
Citrobacter Rodentium ◽  
Bacterial Strains ◽  
Microbial Composition ◽  
Selective Enrichment ◽  
Intestinal Pathogens

The intestinal microbiota plays a key role in shaping the host immune system. Perturbation of gut microbial composition, termed dysbiosis, is associated with an increased susceptibility to intestinal pathogens and is a hallmark of a number of inflammatory, metabolic, and infectious diseases. The prospect of mining the commensal gut microbiota for bacterial strains that can impact immune function represents an attractive strategy to counteract dysbiosis and resulting disease. In this study, we show that selective enrichment of commensal gut lactobacilli protects against the murine pathogen Citrobacter rodentium, a well-characterized model of enteropathogenic and enterohemorrhagic Escherichia coli infection. The lactobacilli-enriched bacterial culture prevented the expansion of Gammaproteobacteria and Actinobacteria and was associated with improved indexes of epithelial barrier function (dextran flux), transmissible crypt hyperplasia, and tissue inflammatory cytokine levels. Moreover, cultivation of gut bacteria from Citrobacter rodentium-infected mice reveals the differential capacity of bacterial subsets to mobilize neutrophil oxidative burst and initiate the formation of weblike neutrophil extracellular traps. Our findings highlight the beneficial effects of a lactobacilli -enriched commensal gut microenvironment and, in the context of an intestinal barrier breach, the ability of neutrophils to immobilize both commensal and pathogenic bacteria.

scholarly journals Transcriptome Profiling and Metagenomic Analysis Help to Elucidate Interactions in an Inflammation-Associated Cancer Mouse Model

Cancers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 3683
Author(s):  
Kazuko Sakai ◽  
Marco A. De Velasco ◽  
Yurie Kura ◽  
Kazuto Nishio
Keyword(s):  
Protein A ◽  
Enrichment Analysis ◽  
Transcriptome Profiling ◽  
Gene Set Enrichment Analysis ◽  
Biosynthetic Pathways ◽  
Microbial Composition ◽  
Gene Set Enrichment ◽  
Downstream Target ◽  
Whole Transcriptome ◽  
16S Rdna Gene Sequencing

Colitis is a risk factor for colorectal cancer (CRC) and can change the dynamics of gut microbiota, leading to dysbiosis and contributing to carcinogenesis. The functional interactions between colitis-associated CRC and microbiota remain unknown. In this study, colitis and CRC were induced in BALB/c mice by the administration of dextran sodium sulfate (DSS) and/or azoxymethane (AOM). Whole transcriptome profiling of normal colon was then performed, and gene set enrichment analysis (GSEA) revealed enriched fatty acid metabolism, oxidative phosphorylation, and PI3K-Akt-mTOR signaling in the tissues from DSS/AOM mice. Additionally, immunohistochemical staining showed increased expression levels of phosphorylated S6 ribosomal protein, a downstream target of the PI3K-Akt-mTOR pathway in the inflamed mucosa of DSS/AOM mice. Fecal microbes were characterized using 16S rDNA gene sequencing. Redundancy analysis demonstrated a significant dissimilarity between the DSS/AOM group and the others. Functional analysis inferred from microbial composition showed enrichments of the sphingolipid signal and lipoarabinomannan biosynthetic pathways. This study provides additional insights into alterations associated with DSS/AOM-induced colitis and associates PI3K-Akt-mTOR, sphingolipid-signaling and lipoarabinomannan biosynthetic pathways in mouse DSS/AOM-induced colitis.

scholarly journals Comparative Genome Analyses of Lactobacillus crispatus Isolates from Different Ecological Niches Reveal an Adaptation of This Species to the Human Vaginal Environment

2021 ◽  
Vol 87 (8) ◽  
Author(s):  
Leonardo Mancabelli ◽  
Walter Mancino ◽  
Gabriele Andrea Lugli ◽  
Christian Milani ◽  
Alice Viappiani ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Vaginal Microbiota ◽  
Microbial Consortia ◽  
Microbial Composition ◽  
Vaginal Infections ◽  
Shotgun Metagenomics ◽  
Content Type ◽  
Lactobacillus Crispatus ◽  
Vaginal Tract

ABSTRACT The vaginal microbiota is defined as the community of bacteria residing in the human vaginal tract. Recent studies have demonstrated that the vaginal microbiota is dominated by members of the Lactobacillus genus, whose relative abundance and microbial taxon composition are dependent on the healthy status of this human body site. Particularly, among members of this genus, the high prevalence of Lactobacillus crispatus is commonly associated with a healthy vaginal environment. In the current study, we assessed the microbial composition of 94 healthy vaginal microbiome samples through shotgun metagenomics analyses. Based on our results, we observed that L. crispatus was the most representative species and correlated negatively with bacteria involved in vaginal infections. Therefore, we isolated 15 L. crispatus strains from different environments in which this species abounds, ranging from vaginal swabs of healthy women to chicken fecal samples. The genomes of these strains were decoded and their genetic content was analyzed and correlated with their physiological features. An extensive comparative genomic analysis encompassing all publicly available genome sequences of L. crispatus and combined with those decoded in this study revealed a genetic adaptation of strains to their respective ecological niche. In addition, in vitro growth experiments involving all isolated L. crispatus strains, together with a synthetic vaginal microbiota, reveal how this species is able to modulate the composition of the vaginal microbial consortia at the strain level. Overall, our findings suggest that L. crispatus plays an important ecological role in reducing the complexity of the vaginal microbiota by depleting pathogenic bacteria. IMPORTANCE The vaginal microbiota is defined as the community of bacteria residing in the human vaginal tract. Recent studies have demonstrated that the high prevalence of Lactobacillus crispatus strains is commonly associated with a healthy vaginal environment. In the current study, we assessed the microbial composition of 94 public healthy vaginal samples through shotgun metagenomics analyses. Results showed that L. crispatus was the most representative species and correlated negatively with bacteria involved in vaginal infections. Moreover, we isolated and sequenced the genomes of new L. crispatus strains from different environments, and the comparative genomics analysis revealed a genetic adaptation of strains to their ecological niche. In addition, in vitro growth experiments display the capability of this species to modulate the composition of the vaginal microbial consortia. Overall, our findings suggest an ecological role exploited by L. crispatus in reducing the complexity of the vaginal microbiota toward a depletion of pathogenic bacteria.

scholarly journals Impacts of Zostera eelgrasses on microbial community structure in San Diego coastal waters

Elem Sci Anth ◽  
2019 ◽  
Vol 7 ◽  
Author(s):  
Sahra J. Webb ◽  
Tia Rabsatt ◽  
Natalia Erazo ◽  
Jeff S. Bowman
Keyword(s):  
Community Structure ◽  
Microbial Community ◽  
Microbial Community Structure ◽  
San Diego ◽  
Pathogenic Bacteria ◽  
Marine Ecosystem ◽  
Rrna Gene ◽  
Microbial Composition ◽  
San Diego Bay ◽  
The Impact

Marine eelgrasses are influential to their surrounding environments through their many ecosystem services, ranging from the provisioning of food and shelter for marine life to serving as a natural defense against pollution and pathogenic bacteria. In the marine waters of San Diego, CA, USA, eelgrass beds comprised of Zostera spp. are an integral part of the coastal ecosystem. To evaluate the impact of eelgrass on bacterial and archaeal community structure we collected water samples in San Diego Bay and sequenced the 16S rRNA gene from paired eelgrass-present and eelgrass-absent sites. To test the hypothesis that microbial community structure is influenced by the presence of eelgrass we applied mixed effects models to these data and to bacterial abundance data derived by flow cytometry. This approach allowed us to identify specific microbial taxa that were differentially present at eelgrass-present and eelgrass-absent sites. Principal coordinate analysis organized the samples by location (inner vs. outer bay) along the first axis, where the first two axes accounted for a 90.8% of the variance in microbial community structure among the samples. Differentially present bacterial taxa included members of the order Rickettsiales, family Flavobacteriaceae, genus Tenacibaculum and members of the order Pseudomonadales. These findings constitute a unique look into the microbial composition of San Diego Bay and examine how eelgrasses contribute to marine ecosystem health, e.g., by supporting specific microbial communities and by filtering and trapping potentially harmful bacteria to the benefit of marine organisms.

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