Disruption of skin microbiota contributes to salamander disease

Escalating occurrences of emerging infectious diseases underscore the importance of understanding microbiome–pathogen interactions. The amphibian cutaneous microbiome is widely studied for its potential to mitigate disease-mediated amphibian declines. Other microbial interactions in this system, however, have been largely neglected in the context of disease outbreaks. European fire salamanders have suffered dramatic population crashes as a result of the newly emerged Batrachochytrium salamandrivorans ( Bsal ). In this paper, we investigate microbial interactions on multiple fronts within this system. We show that wild, healthy fire salamanders maintain complex skin microbiotas containing Bsal -inhibitory members, but these community are present at a remarkably low abundance. Through experimentation, we show that increasing bacterial densities of Bsal -inhibiting bacteria via daily addition slowed disease progression in fire salamanders. Additionally, we find that experimental- Bsal infection elicited subtle changes in the skin microbiome, with selected opportunistic bacteria increasing in relative abundance resulting in septicemic events that coincide with extensive destruction of the epidermis. These results suggest that fire salamander skin, in natural settings, maintains bacterial communities at numbers too low to confer sufficient protection against Bsal, and, in fact, the native skin microbiota can constitute a source of opportunistic bacterial pathogens that contribute to pathogenesis. By shedding light on the complex interaction between the microbiome and a lethal pathogen, these data put the interplay between skin microbiomes and a wildlife disease into a new perspective.

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Dynamics of host populations affected by the emerging fungal pathogen Batrachochytrium salamandrivorans

Royal Society Open Science ◽

10.1098/rsos.160801 ◽

2017 ◽

Vol 4 (3) ◽

pp. 160801 ◽

Cited By ~ 16

Author(s):

Benedikt R. Schmidt ◽

Claudio Bozzuto ◽

Stefan Lötters ◽

Sebastian Steinfartz

Keyword(s):

Emerging Infectious Diseases ◽

Disease Outbreaks ◽

Host Population ◽

Mitigation Measures ◽

Disease Emergence ◽

Batrachochytrium Salamandrivorans ◽

In The Wild ◽

Successful Control ◽

Using Data ◽

Local Extirpation

Emerging infectious diseases cause extirpation of wildlife populations. We use an epidemiological model to explore the effects of a recently emerged disease caused by the salamander-killing chytrid fungus Batrachochytrium salamandrivorans ( Bsal ) on host populations, and to evaluate which mitigation measures are most likely to succeed. As individuals do not recover from Bsal , we used a model with the states susceptible, latent and infectious, and parametrized the model using data on host and pathogen taken from the literature and expert opinion. The model suggested that disease outbreaks can occur at very low host densities (one female per hectare). This density is far lower than host densities in the wild. Therefore, all naturally occurring populations are at risk. Bsal can lead to the local extirpation of the host population within a few months. Disease outbreaks are likely to fade out quickly. A spatial variant of the model showed that the pathogen could potentially spread rapidly. As disease mitigation during outbreaks is unlikely to be successful, control efforts should focus on preventing disease emergence and transmission between populations. Thus, this emerging wildlife disease is best controlled through prevention rather than subsequent actions.

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Secretory Proteases of the Human Skin Microbiome

Infection and Immunity ◽

10.1128/iai.00397-21 ◽

2021 ◽

Author(s):

Wisely Chua ◽

Si En Poh ◽

Hao Li

Keyword(s):

Human Skin ◽

Hydrolytic Enzymes ◽

Microbial Interactions ◽

Skin Microbiome ◽

Protein Cleavage ◽

Wide Range ◽

Range Of Functions ◽

Diverse Community ◽

Secreted Proteases ◽

Pathogenic Agents

The human skin is our outermost layer and serves as a protective barrier against external insults. Advances in next generation sequencing have enabled the discoveries of a rich and diverse community of microbes - bacteria, fungi and viruses that are residents of this surface. The genomes of these microbes also revealed the presence of many secretory enzymes. In particular, proteases which are hydrolytic enzymes capable of protein cleavage and degradation are of special interest in the skin environment which is enriched in proteins and lipids. In this minireview, we will focus on the roles of these skin-relevant microbial secreted proteases, both in terms of their widely studied roles as pathogenic agents in tissue invasion and host immune inactivation, and their recently discovered roles in inter-microbial interactions and modulation of virulence factors. From these studies, it has become apparent that while microbial proteases are capable of a wide range of functions, their expression is tightly regulated and highly responsive to the environments the microbes are in. With the introduction of new biochemical and bioinformatics tools to study protease functions, it will be important to understand the roles played by skin microbial secretory proteases in cutaneous health, especially the less studied commensal microbes with an emphasis on contextual relevance.

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Microbiome and Metabolome Analyses Reveal Novel Interplay Between the Skin Microbiota and Plasma Metabolites in Psoriasis

Frontiers in Microbiology ◽

10.3389/fmicb.2021.643449 ◽

2021 ◽

Vol 12 ◽

Author(s):

Dongmei Chen ◽

Jingquan He ◽

Jinping Li ◽

Qian Zou ◽

Jiawei Si ◽

...

Keyword(s):

Lipid Metabolism ◽

Metabolic Pathways ◽

Pathogenic Bacteria ◽

Plasma Metabolites ◽

Skin Microbiome ◽

Inflammatory Skin Disease ◽

Skin Microbiota ◽

Plasma Metabolome ◽

Pathological Mechanism ◽

New Evidence

Psoriasis is a chronic inflammatory skin disease that affects millions of people worldwide. There is still no effective approach for the clinical treatment of psoriasis. This is largely due to the lack of understanding of the pathological mechanism. Here, we comprehensively characterized the skin microbiome and plasma metabolome alterations of psoriasis patients. We observed that some pathogenic bacteria, including Vibrio, were significantly increased in psoriasis patients. The metabolomics results showed alterations in some metabolic pathways, especially pathways for lipid metabolism. In addition, microbiome-specific metabolites, including bile acids and kynurenine, were significantly changed. Correlation analysis revealed the interplay between the skin microbiota and plasma metabolites, especially between Vibrio and several lipids. Our results provide new evidence for the interplay between the skin microbiome and plasma metabolites, which is dramatically disrupted in psoriasis patients. This study also revealed the mechanism underlying the pathogenesis of psoriasis.

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Rhodomyrtus tomentosa Fruit Extract and Skin Microbiota: A Focus on C. acnes Phylotypes in Acne Subjects

Cosmetics ◽

10.3390/cosmetics7030053 ◽

2020 ◽

Vol 7 (3) ◽

pp. 53 ◽

Cited By ~ 1

Author(s):

Sandie Gervason ◽

Isabelle Metton ◽

Elodie Gemrot ◽

Edwige Ranouille ◽

Gilbert Skorski ◽

...

Keyword(s):

Active Ingredient ◽

16S Rrna Gene Sequencing ◽

Rrna Gene ◽

Skin Microbiome ◽

Skin Microbiota ◽

Cutibacterium Acnes ◽

Culture Independent ◽

Rrna Gene Sequencing ◽

Abundant Genus ◽

Rhodomyrtus Tomentosa

Knowing that Rhodomyrtus tomentosa is known to have antibacterial effects, this study investigated the skin microbiota with a focus on Cutibacterium acnes (C. acnes) phylotypes in subjects with acne, and determined microbiota changes after 28 days of treatment with berries Rhodomyrtus tomentosa as an active ingredient (RT). Skin swabs from seventeen acne subjects were collected and the skin microbiome was analyzed using 16S rRNA gene sequencing. A culture-independent next-generation sequencing (NGS)-based SLST (single-locus sequence typing) approach was aimed at evaluating RT extract effects on C. acnes phylotype repartition. Clinical evaluations (lesion counts) were performed at baseline (D0) and after 28 days (D28) of twice-daily application of the RT active ingredient. We determined: (1) the skin microbiota at D0 was dominated by Actinobacteria followed by Firmicutes and Proteobacteria; (2) at the genus level, Cutibacterium was the most abundant genus followed by Staphylococcus and Corynebacterium; (3) C. acnes was the major species in terms of mean abundance, followed by Staphylococcus epidermidis (S. epidermidis) and Staphylococcus hominis (S. hominis); and (4) phylotype IA1 was most represented, with a predominance of SLST type A1, followed by phylotypes II, IB, IA2, IC, and III. After 28 days of RT extract treatment, phylotype repartition were modified with a decrease in abundance (approximately 4%) of phylotype IA1 and an increase in phylotype II and III. Cutibacterium granulosum (C. granulosum) abundance also decreased. Reduction of retentional and inflammatory lesions was also noted only after RT treatment; thus, RT extract acts as a microbiota-regulating agent.

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Habitat disturbance influences the skin microbiome of a rediscovered neotropical-montane frog

BMC Microbiology ◽

10.1186/s12866-020-01979-1 ◽

2020 ◽

Vol 20 (1) ◽

Author(s):

Randall R. Jiménez ◽

Gilbert Alvarado ◽

José Sandoval ◽

Simone Sommer

Keyword(s):

Relative Abundance ◽

Bacterial Communities ◽

Environmental Changes ◽

Defense Mechanism ◽

Anthropogenic Activities ◽

Habitat Disturbance ◽

Amphibian Declines ◽

Stress Factors ◽

Skin Microbiome ◽

Disturbed Habitats

Abstract Background The skin microbiome serves as a first line defense against pathogens in vertebrates. In amphibians, it has the potential to protect against the chytrid fungus Batrachochytrium dendrobatis (Bd), a likely agent of amphibian declines. Alteration of the microbiome associated with unfavorable environmental changes produced by anthropogenic activities may make the host more susceptible to pathogens. Some amphibian species that were thought to be “extinct” have been rediscovered years after population declines in the late 1980s probably due to evolved Bd-resistance and are now threatened by anthropogenic land-use changes. Understanding the effects of habitat disturbance on the host skin microbiome is relevant for understanding the health of these species, along with its susceptibility to pathogens such as Bd. Here, we investigate the influence of habitat alteration on the skin bacterial communities as well as specifically the putative Bd-inhibitory bacterial communities of the montane frog Lithobates vibicarius. This species, after years of not being observed, was rediscovered in small populations inhabiting undisturbed and disturbed landscapes, and with continuous presence of Bd. Results We found that cutaneous bacterial communities of tadpoles and adults differed between undisturbed and disturbed habitats. The adults from disturbed habitats exhibited greater community dispersion than those from undisturbed habitats. We observed a higher richness of putative Bd-inhibitory bacterial strains in adults from disturbed habitats than in those from undisturbed habitats, as well as a greater number of these potential protective bacteria with a high relative abundance. Conclusions Our findings support the microbial “Anna Karenina principle”, in which disturbance is hypothesized to cause greater microbial dispersion in communities, a so-called dysbiosis, which is a response of animal microbiomes to stress factors that decrease the ability of the host or its microbiome to regulate community composition. On the positive side, the high richness and relative abundance of putative Bd-inhibitory bacteria may indicate the development of a defense mechanism that enhances Bd-protection, attributed to a co-occurrence of more than 30-years of host and pathogen in these disturbed habitats. Our results provide important insight into the influence of human-modified landscapes on the skin microbiome and health implications of Bd-survivor species.

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A New Look at Cardiac Defense: Attention or Emotion?

The Spanish Journal of Psychology ◽

10.1017/s1138741600005217 ◽

2003 ◽

Vol 6 (1) ◽

pp. 60-78 ◽

Cited By ~ 11

Author(s):

Jaime Vila ◽

María Carmen Fernández ◽

Joaquín Pegalajar ◽

María Nieves Vera ◽

Humbelina Robles ◽

...

Keyword(s):

Psychological Research ◽

Cognitive Approach ◽

Psychological Mechanisms ◽

Health And Illness ◽

Parametric Studies ◽

Parasympathetic Influences ◽

New Perspective ◽

Natural Settings ◽

Traditional Approaches ◽

New Look

The study of cardiac defense has a long tradition in psychological research both within the cognitive approach—linked to Pavlov, Sokolov, and Graham's work on sensory reflexes—and within the motivational one—linked to the work of Cannon and subsequent researchers on the concepts of activation and stress. These two approaches have been difficult to reconcile in the past. We summarize a series of studies on cardiac defense from a different perspective, which allows integration of the traditional approaches. This new perspective emphasizes a sequential process interpretation of the cardiac defense response. Results of descriptive and parametric studies, as well as those of studies examining the physiological and psychological mechanisms underlying the response, show a complex response pattern with both accelerative and decelerative components, with both sympathetic and parasympathetic influences, and with both attentional and emotional significance. The implications of this new look at cardiac defense are discussed in relation to defensive reactions in natural settings, the brain mechanisms controlling such reactions, and their effects on health and illness.

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Profiling Skin Microbiome in Healthy Young Adult Representing Javanese, Papuans, and Chinese Descent in Indonesia

HAYATI Journal of Biosciences ◽

10.4308/hjb.28.4.249-261 ◽

2021 ◽

Vol 28 (4) ◽

pp. 249-261

Author(s):

Stella Vania ◽

Amarila Malik

Keyword(s):

Skin Diseases ◽

Geographical Location ◽

Alpha Diversity ◽

Ethnic Origin ◽

Skin Microbiome ◽

Microbiota Composition ◽

Skin Microbiota ◽

Pathogen Invasion ◽

Chinese Descent ◽

Microbiome Research

Skin serves as the first physical barrier and biological barrier by the colonization of commensal bacteria to prevent pathogen invasion. It was known that the disruption on normal commensal microbiota composition or dysbiosis causes skin diseases, while the skin microbiota diversity itself is influenced by several factors, one of them is ethnicity. This study shows the influence of ethnicity factor in Papuans, Javanese, and Chinese descent young adults living in Jakarta on skin microbiome profiles. The microbiota genomic DNA are extracted from the face skin samples and sequenced with Next Generation Sequencing method to be further analyzed. The result shows that individuals with the same ethnic background share similar skin microbiome characteristics. The greatest skin microbiome alpha diversity is shown by the Papuans and the Chinese descent the smallest. Ethnicity factor that shows statistically significant differences in interindividual dissimilarities are independent of other intriguing factors such as age, geographical location, etc. Therefore the ethnic origin of individuals especially from three ethnics above is a factor to be considered in skin microbiome research and the skin microbiota composition can be used for potential future applications.

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Emergence of evidence during disease outbreaks: lessons learnt from the Zika virus outbreak

10.1101/2020.03.16.20036806 ◽

2020 ◽

Cited By ~ 1

Author(s):

Michel J Counotte ◽

Kaspar W Meili ◽

Nicola Low

Keyword(s):

Infectious Diseases ◽

Study Design ◽

Zika Virus ◽

Case Reports ◽

Emerging Infectious Diseases ◽

Case Series ◽

Disease Outbreaks ◽

Basic Research ◽

First Case ◽

Over Time

AbstractIntroductionOutbreaks of infectious diseases trigger an increase in scientific research and output. Early in outbreaks, evidence is scarce, but it accumulates rapidly. We are continuously facing new disease outbreaks, including the new coronavirus (SARS-nCoV-2) in December 2019.The objective of this study was to describe the accumulation of evidence during the 2013-2016 Zika virus (ZIKV) outbreak in the Pacific and the Americas related to aetiological causal questions about congenital abnormalities and Guillain-Barré syndrome.MethodsWe hypothesised that the temporal sequence would follow a pre-specified order, according to study design. We assessed 1) how long it takes before findings from a specific study design appear, 2) how publication of preprints could reduce the time to publication and 3) how time to publication evolves over time.ResultsWe included 346 publications published between March 6, 2014 and January 1, 2019. In the 2013-–2016 ZIKV outbreak, case reports, case series and basic research studies were published first. Case-control and cohort studies appeared between 400–700 days after ZIKV was first detected in the region of the study origin. Delay due to the publication process were lowest at the beginning of the outbreak. Only 4.6% of the publications was available as preprints.DiscussionThe accumulation of evidence over time in new causal problems generally followed a hierarchy. Preprints reduced the delay to initial publication. Our methods can be applied to new emerging infectious diseases.

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Chronic Diseases Associated with Malassezia Yeast

10.20944/preprints202109.0416.v1 ◽

2021 ◽

Author(s):

Abdourahim Abdillah ◽

Stéphane Ranque

Keyword(s):

Colorectal Cancer ◽

Chronic Diseases ◽

Normal Skin ◽

Human Diseases ◽

Skin Microbiome ◽

Body Site ◽

Inflammatory Bowel ◽

New Perspective ◽

Malassezia Spp ◽

Shed Light

Malassezia are lipid-dependent basidiomycetous yeast of the normal skin microbiome, although Malassezia DNA has been recently detected in other body sites and has been associated with cer-tain chronic human diseases. This new perspective raises many questions. Are these yeasts truly present in the investigated body site or were they contaminated by other body sites, adjacent or not? Does this DNA contamination come from living or dead yeast? If these yeasts are alive, do they belong to the resident mycobiota or are they transient colonizers which are not permanently established within these niches? And, finally, are these yeasts associated with certain chronic diseases or not? In an attempt to shed light on this knowledge gap, we critically re-viewed the 31 published studies focusing on the association of Malassezia spp. with chronic human diseases, including psoriasis, atopic dermatitis (AD), chronic rhinosinusitis (CRS), asthma, cystic fibrosis (CF), HIV infection, inflammatory bowel disease (IBD), colorectal cancer (CRC), and neurodegenerative diseases.

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Effect of treatments on skin microbiota in patients with atopic dermatitis: a protocol for systematic review

BMJ Open ◽

10.1136/bmjopen-2021-053488 ◽

2022 ◽

Vol 12 (1) ◽

pp. e053488

Author(s):

Yang Guo ◽

Xia Dou ◽

Xing-ling Jian ◽

Kao-yuan Zhang ◽

Ying-jie Zheng ◽

...

Keyword(s):

Systematic Review ◽

Atopic Dermatitis ◽

Data Extraction ◽

Risk Of Bias ◽

Microbial Interactions ◽

Skin Microbiota ◽

Clinical Trial Registry ◽

Bias Assessment ◽

Study Selection ◽

Registration Number

IntroductionAtopic dermatitis (AD) is a chronic inflammatory skin disease and skin microbiota dysbiosis shows an important role in the pathogenesis of AD. Effects of treatment on skin microbiota for patients with AD have been evaluated in recent years; however, the results remained controversial across studies. This systematic review will summarise studies evaluating the effect of treatments on skin microbiota among patients with AD.Methods and analysisWe will search PubMed, EMBASE, Web of Science, ClinicalTrials.gov and Chinese Clinical Trial Registry in November 2021; other data sources will also be considered, including searching specific authors and screening references cited in the enrolled articles. Interventional studies, which enrolled patients with AD receiving treatments and reported treatment-related skin microbiota changes, will be included. Our primary outcomes include skin microbiota diversity and treatment-related differential microbes; the secondary outcomes include microbiota functions and microbial interactions. Risk of bias assessment will be performed using Cochrane risk-of-bias tool for randomised trials, risk of bias in non-randomised studies of interventions and methodological index for non-randomised studies. Two researchers will independently perform study selection, data extraction and risk of bias assessment, with disagreements resolved by group discussions. Subgroup analyses will be performed according to different types of treatment for AD.Ethics and disseminationEthics approval is not required for this systematic review. Findings will be disseminated via peer-reviewed publication or conference proceedings.PROSPERO registration numberCRD42021246566.

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