scholarly journals Skin bacteria of rainbow trout antagonistic to the fish pathogen Flavobacterium psychrophilum

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mio Takeuchi ◽  
Erina Fujiwara-Nagata ◽  
Taiki Katayama ◽  
Hiroaki Suetake
Keyword(s):  
Rainbow Trout ◽  
Culture Media ◽  
Amplicon Sequencing ◽  
Effective Vaccine ◽  
Rrna Gene ◽  
Skin Microbiome ◽  
Fish Disease ◽  
Flavobacterium Psychrophilum ◽  
Skin Bacteria ◽  
Coldwater Disease

AbstractRainbow trout fry syndrome (RTFS) and bacterial coldwater disease (BCWD) is a globally distributed freshwater fish disease caused by Flavobacterium psychrophilum. In spite of its importance, an effective vaccine is not still available. Manipulation of the microbiome of skin, which is a primary infection gate for pathogens, could be a novel countermeasure. For example, increasing the abundance of specific antagonistic bacteria against pathogens in fish skin might be effective to prevent fish disease. Here, we combined cultivation with 16S rRNA gene amplicon sequencing to obtain insight into the skin microbiome of the rainbow trout (Oncorhynchus mykiss) and searched for skin bacteria antagonistic to F. psychrophilum. By using multiple culture media, we obtained 174 isolates spanning 18 genera. Among them, Bosea sp. OX14 and Flavobacterium sp. GL7 respectively inhibited the growth of F. psychrophilum KU190628-78 and NCIMB 1947T, and produced antagonistic compounds of < 3 kDa in size. Sequences related to our isolates comprised 4.95% of skin microbial communities, and those related to strains OX14 and GL7 respectively comprised 1.60% and 0.17% of the skin microbiome. Comparisons with previously published microbiome data detected sequences related to strains OX14 and GL7 in skin of other rainbow trout and Atlantic salmon.

scholarly journals Pre-digest of unprotected DNA by Benzonase improves the representation of living skin bacteria and efficiently depletes host DNA

Microbiome ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Yacine Amar ◽  
Ilias Lagkouvardos ◽  
Rafaela L. Silva ◽  
Oluwaseun Ayodeji Ishola ◽  
Bärbel U. Foesel ◽  
...  
Keyword(s):  
Defense Mechanisms ◽  
Bacterial Load ◽  
16S Rrna Gene Sequencing ◽  
Rrna Gene ◽  
Skin Microbiome ◽  
Mock Community ◽  
Skin Bacteria ◽  
Α Diversity ◽  
Microbial Turnover ◽  
Microbial Dna

Abstract Background The identification of microbiota based on next-generation sequencing (NGS) of extracted DNA has drastically improved our understanding of the role of microbial communities in health and disease. However, DNA-based microbiome analysis cannot per se differentiate between living and dead microorganisms. In environments such as the skin, host defense mechanisms including antimicrobial peptides and low cutaneous pH result in a high microbial turnover, likely resulting in high numbers of dead cells present and releasing substantial amounts of microbial DNA. NGS analyses may thus lead to inaccurate estimations of microbiome structures and consequently functional capacities. Results We investigated in this study the feasibility of a Benzonase-based approach (BDA) to pre-digest unprotected DNA, i.e., of dead microbial cells, as a method to overcome these limitations, thus offering a more accurate assessment of the living microbiome. A skin mock community as well as skin microbiome samples were analyzed using 16S rRNA gene sequencing and metagenomics sequencing after DNA extraction with and without a Benzonase digest to assess bacterial diversity patterns. The BDA method resulted in less reads from dead bacteria both in the skin mock community and skin swabs spiked with either heat-inactivated bacteria or bacterial-free DNA. This approach also efficiently depleted host DNA reads in samples with high human-to-microbial DNA ratios, with no obvious impact on the microbiome profile. We further observed that low biomass samples generate an α-diversity bias when the bacterial load is lower than 105 CFU and that Benzonase digest is not sufficient to overcome this bias. Conclusions The BDA approach enables both a better assessment of the living microbiota and depletion of host DNA reads. Graphical abstract

scholarly journals Habitat and Client Diversity Influence the Skin Microbiome of the Caribbean Cleaner Goby Elacatinus Evelynae

2021 ◽  
Author(s):  
Ana Pereira ◽  
Marta C. Soares ◽  
Teresa Santos ◽  
Ana Poças ◽  
Marcos Pérez-Losada ◽  
...  
Keyword(s):  
Coral Reefs ◽  
Virgin Islands ◽  
Physical Contact ◽  
Rrna Gene ◽  
Skin Microbiome ◽  
Us Virgin Islands ◽  
Alpha And Beta Diversity ◽  
Skin Bacteria ◽  
The Caribbean ◽  
Microbiota Diversity

Abstract Fish associated microorganisms are known to be affected by the environment and other external factors, such as microbial transfer between interacting partners. One of the most iconic mutualistic interactions on coral reefs are the cleaning interactions between cleanerfishes and their clients, during which direct physical contact occurs. Here, we characterized the skin bacteria of the Caribbean cleaner sharknose goby, Elacatinus evelynae, in four coral reefs of the US Virgin Islands using sequencing of the V4 region of the 16S rRNA gene. We specifically tested the relationship between gobies’ level of interaction with clients and skin microbiota diversity and composition. Our results showed differences in microbial alpha- and beta-diversity in the skin of gobies from different reef habitats and high inter-individual variation in microbiota diversity and structure. Overall, the results showed that fish-to-fish direct contact and specifically, access to a diverse clientele, influences the bacterial diversity and structure of cleaner gobies’ skin. Because of their frequent contact with clients, and therefore, high potential for microbial exchange, cleanerfish may serve as models in future studies aiming to understand the role of social microbial transfer in reef fish communities.

scholarly journals Influences of Ingredients and Bakers on the Bacteria and Fungi in Sourdough Starters and Bread

mSphere ◽  
2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Aspen T. Reese ◽  
Anne A. Madden ◽  
Marie Joossens ◽  
Guylaine Lacaze ◽  
Robert R. Dunn
Keyword(s):  
Microbial Community ◽  
Internal Transcribed Spacer ◽  
Amplicon Sequencing ◽  
Rrna Gene ◽  
Skin Microbiome ◽  
Relative Importance ◽  
Naturally Occurring ◽  
Sourdough Bread ◽  
Bacteria And Fungi ◽  
Bidirectional Exchange

ABSTRACT Sourdough starters are naturally occurring microbial communities in which the environment, ingredients, and bakers are potential sources of microorganisms. The relative importance of these pools remains unknown. Here, bakers from two continents used a standardized recipe and ingredients to make starters that were then baked into breads. We characterized the fungi and bacteria associated with the starters, bakers’ hands, and ingredients using 16S and internal transcribed spacer (ITS) rRNA gene amplicon sequencing and then measured dough acidity and bread flavor. Starter communities were much less uniform than expected, and this variation manifested in the flavor of the bread. Starter communities were most similar to those found in flour but shared some species with the bakers’ skin. While humans likely contribute microorganisms to the starters, the reverse also appears to be true. This bidirectional exchange of microorganisms between starters and bakers highlights the importance of microbial diversity on bodies and in our environments as it relates to foods. IMPORTANCE Sourdough starters are complex communities of yeast and bacteria which confer characteristic flavor and texture to sourdough bread. The microbes present in starters can be sourced from ingredients or the baking environment and are typically consistent over time. Herein, we show that even when the recipe and ingredients for starter and bread are identical, different bakers around the globe produce highly diverse starters which then alter bread acidity and flavor. Much of the starter microbial community comes from bread flour, but the diversity is also associated with differences in the microbial community on the hands of bakers. These results indicate that bakers may be a source for yeast and bacteria in their breads and/or that bakers’ jobs are reflected in their skin microbiome.

Phenotypic and genotypic analysis of Flavobacterium psychrophilum isolates from Ontario salmonids with bacterial coldwater disease

2008 ◽  
Vol 54 (8) ◽  
pp. 619-629 ◽  
Author(s):  
Shohreh Hesami ◽  
Katie J. Allen ◽  
Devon Metcalf ◽  
Vaughn E. Ostland ◽  
Janet I. MacInnes ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Rainbow Trout ◽  
16S Rrna ◽  
Sequence Type ◽  
Chain Reaction ◽  
Flavobacterium Psychrophilum ◽  
Genotypic Analysis ◽  
Polymerase Chain ◽  
Coldwater Disease ◽  
Bacterial Coldwater Disease

Flavobacterium psychrophilum is the causative agent of bacterial coldwater disease (BCWD) and rainbow trout fry syndrome. BCWD has a considerable economic impact on aquaculture operations in Ontario, Canada, and our limited understanding of the population structure and epidemiology of F. psychrophilum isolates is an impediment to the development of improved management strategies. Seventy-five 16S rRNA gene and gyr polymerase chain reaction positive isolates of F. psychrophilum that had been collected over a 16-year period from farmed salmonids with tail rot, necrotic myositis, and osteochondrosis were characterized morphologically, biochemically, and genotypically. Although the isolates were homogeneous by preliminary biochemical and phenotypic characterization, two distinct biovars were found by API ZYM testing. As well, four restriction pattern types were detected by 16S rRNA polymerase chain reaction – restriction fragment length polymorphism analysis and there was a significant (P < 0.001) correlation between biovar I and digestion with MaeIII and between biovar II and digestion with MnlI or no site (P < 0.05). Further heterogenity was detected by sequence analysis of a 194 bp stem loop 3 region of rRNA. Nine sequence types were identified; 40/46 biovar I isolates were sequence type “a”, while 21/32 biovar II isolates belonged to either sequence type “c” or “d”. More than one biovar and genotype was identified among the strains recovered from separate fish sampled from three groups of rainbow trout ( Oncorhynchus mykiss ) experiencing BCWD mortality events. No association was found between genotype or biovar and type of disease. Taken together, these data suggest that F. psychrophilum from Ontario can be grouped into two major lineages based on biovar and 16S rRNA polymorphisms, and although three major strain types were most frequently isolated in this study, it appears that the population of F. psychrophilum with pathogenic potential is quite heterogeneous.

scholarly journals Large-Scale Analysis ofFlavobacterium psychrophilumMultilocus Sequence Typing Genotypes Recovered from North American Salmonids Indicates that both Newly Identified and Recurrent Clonal Complexes Are Associated with Disease

2019 ◽  
Vol 85 (6) ◽  
Author(s):  
Christopher Knupp ◽  
Gregory D. Wiens ◽  
Mohamed Faisal ◽  
Douglas R. Call ◽  
Kenneth D. Cain ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Rainbow Trout ◽  
North America ◽  
North American ◽  
Economic Losses ◽  
Content Type ◽  
Flavobacterium Psychrophilum ◽  
Coldwater Disease ◽  
Rainbow Trout Fry Syndrome ◽  
Bacterial Coldwater Disease

ABSTRACTFlavobacterium psychrophilum, the etiological agent of bacterial coldwater disease (BCWD) and rainbow trout fry syndrome (RTFS), causes significant economic losses in salmonid aquaculture, particularly in rainbow trout (Oncorhynchus mykiss). Prior studies have used multilocus sequence typing (MLST) to examine genetic heterogeneity withinF. psychrophilum. At present, however, its population structure in North America is incompletely understood, as only 107 isolates have been genotyped. Herein, MLST was used to investigate the genetic diversity of an additional 314 North AmericanF. psychrophilumisolates that were recovered from ten fish host species from 20 U.S. states and 1 Canadian province over nearly four decades. These isolates were placed into 66 sequence types (STs), 47 of which were novel, increasing the number of clonal complexes (CCs) in North America from 7 to 12. Newly identified CCs were diverse in terms of host association, distribution, and association with disease. The largestF. psychrophilumCC identified was CC-ST10, within which 10 novel genotypes were discovered, most of which came fromO. mykissexperiencing BCWD. This discovery, among others, provides evidence for the hypothesis that ST10 (i.e., the founding ST of CC-ST10) originated in North America. Furthermore, ST275 (in CC-ST10) was recovered from wild/feral adult steelhead and marks the first recovery of CC-ST10 from wild/feral fish in North America. Analyses also revealed that at the allele level, the diversification ofF. psychrophilumin North America is driven three times more frequently by recombination than random nucleic acid mutation, possibly indicating how new phenotypes emerge within this species.IMPORTANCEFlavobacterium psychrophilumis the causative agent of bacterial coldwater disease (BCWD) and rainbow trout fry syndrome (RTFS), both of which cause substantial losses in farmed fish populations worldwide. To better prevent and control BCWD and RTFS outbreaks, we sought to characterize the genetic diversity of several hundredF. psychrophilumisolates that were recovered from diseased fish across North America. Results highlighted multipleF. psychrophilumgenetic strains that appear to play an important role in disease events in North American aquaculture facilities and suggest that the practice of trading fish eggs has led to the continental and transcontinental spread of this bacterium. The knowledge generated herein will be invaluable toward guiding the development of future disease prevention techniques.

scholarly journals Segregation of age-related skin microbiome characteristics by functionality

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Hye-Jin Kim ◽  
Jin Ju Kim ◽  
Nu Ri Myeong ◽  
Taeyune Kim ◽  
DooA Kim ◽  
...  
Keyword(s):  
Chinese Women ◽  
Age Groups ◽  
Amplicon Sequencing ◽  
Skin Aging ◽  
Future Research ◽  
Rrna Gene ◽  
Skin Microbiome ◽  
Age Related ◽  
Functional Pathways ◽  
Two Age Groups

AbstractAlthough physiological changes are the most evident indicators of skin aging by alteration of the skin’s structure and function, we question whether skin aging is also affected by the structure and assembly process of the skin microbiome. We analysed the skin microbiomes of 73 healthy Chinese women in two age groups (25–35 years old and 56–63 years old) using 16S rRNA gene amplicon sequencing; the overall microbiome structure was significantly different between the two age groups. An analysis using ecological theory to evaluate the process of microbial community assembly processes revealed that the microbiomes of the older group were formed under a greater influence of the niche-based process, with the network of microbes being more collapsed than that of the younger group. Inferred metagenomic functional pathways associated with replication and repair were relatively more predominant in the younger group whereas, among the various metabolism-related pathways, those associated with biodegradation were more predominant in the older group. Interestingly, we found two segregated sub-typing patterns in the younger group which were also observed in the skin microbiomes of young Chinese women living in four other cities in China. The results of our study highlights candidate microbes and functional pathways that are important for future research into preventing skin aging and which could lead to a comprehensive understanding of age-related skin microbiome characteristics.

scholarly journals Seasonal and ontogenetic variation of skin microbial communities and relationships to natural disease dynamics in declining amphibians

2015 ◽  
Vol 2 (7) ◽  
pp. 140377 ◽  
Author(s):  
Ana V. Longo ◽  
Anna E. Savage ◽  
Ian Hewson ◽  
Kelly R. Zamudio
Keyword(s):  
Bacterial Diversity ◽  
Batrachochytrium Dendrobatidis ◽  
Developmental Stages ◽  
Pathogenic Fungus ◽  
Natural Populations ◽  
Amplicon Sequencing ◽  
Protective Role ◽  
Skin Microbiome ◽  
Skin Bacteria

Recently, microbiologists have focused on characterizing the probiotic role of skin bacteria for amphibians threatened by the fungal disease chytridiomycosis. However, the specific characteristics of microbial diversity required to maintain health or trigger disease are still not well understood in natural populations. We hypothesized that seasonal and developmental transitions affecting susceptibility to chytridiomycosis could also alter the stability of microbial assemblages. To test our hypothesis, we examined patterns of skin bacterial diversity in two species of declining amphibians ( Lithobates yavapaiensis and Eleutherodactylus coqui ) affected by the pathogenic fungus Batrachochytrium dendrobatidis ( Bd ). We focused on two important transitions that affect Bd susceptibility: ontogenetic (from juvenile to adult) shifts in E. coqui and seasonal (from summer to winter) shifts in  L. yavapaiensis . We used a combination of community-fingerprinting analyses and 16S rRNA amplicon sequencing to quantify changes in bacterial diversity and assemblage composition between seasons and developmental stages, and to investigate the relationship between bacterial diversity and pathogen load. We found that winter-sampled frogs and juveniles, two states associated with increased Bd susceptibility, exhibited higher diversity compared with summer-sampled frogs and adult individuals. Our findings also revealed that hosts harbouring higher bacterial diversity carried lower Bd infections, providing support for the protective role of bacterial communities. Ongoing work to understand skin microbiome resilience after pathogen disturbance has the potential to identify key taxa involved in disease resistance.

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