Social Immunity in Amphibians: Evidence for Vertical Transmission of Innate Defenses

Walke, Jenifer B.; Harris, Reid N.; Reinert, Laura K.; Rollins‐Smith, Louise A.; Woodhams, Douglas C.

doi:10.1111/j.1744-7429.2011.00787.x

Cited by 101 publications

(114 citation statements)

References 43 publications

(95 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…int-res. com/ articles/ suppl/ d103 p077_supp.pdf) are in line with those found on frogs in other studies (Woodhams et al 2007b, Walke et al 2011.…”

Section: Discussionsupporting

confidence: 80%

“…Microbes that colonise amphibian skin can also confer disease resistance on their hosts (Bettin & Greven 1986, Harris et al 2006, Lauer et al 2007, 2008, Woodhams et al 2007b, Banning et al 2008. Symbiotic microbes can therefore be regarded as another component of amphibians' innate immune defence mechanisms (Woodhams et al 2007b, Walke et al 2011. Symbiotic bacteria resident on anuran skin may sometimes play a greater role than AMPs in defence against Bd, and AMP potency may be attenuated in species that rely heavily on their beneficial microbiota (Conlon 2011).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Screening bacterial metabolites for inhibitory effects against Batrachochytrium dendrobatidis using a spectrophotometric assay

Bell¹,

Alford²,

Garland³

et al. 2013

Dis. Aquat. Org.

View full text Add to dashboard Cite

Certain bacteria present on frog skin can prevent infection by the pathogenic fungus Batrachochytrium dendrobatidis (Bd), conferring disease resistance. Previous studies have used agar-based in vitro challenge assays to screen bacteria for Bd-inhibitory activity and to identify candidates for bacterial supplementation trials. However, agar-based assays can be difficult to set up and to replicate reliably. To overcome these difficulties, we developed a semi-quantitative spectrophotometric challenge assay technique. Cell-free supernatants were prepared from filtered bacterial cultures and added to 96-well plates in replicated wells containing Bd zoospores suspended in tryptone-gelatin hydrolysate-lactose (TGhL) broth medium. Plates were then read daily on a spectrophotometer until positive controls reached maximum growth in order to determine growth curves for Bd. We tested the technique by screening skin bacteria from the Australian green-eyed tree frog Litoria serrata. Of bacteria tested, 31% showed some degree of Bd inhibition, while some may have promoted Bd growth, a previously unknown effect. Our cell-free supernatant challenge assay technique is an effective in vitro method for screening bacterial isolates for strong Bd-inhibitory activity. It contributes to the expanding field of bioaugmentation research, which could play a significant role in mitigating the effects of chytridiomycosis on amphibians around the world. KEY WORDS: Chytridiomycosis · Challenge assay · Bacterial metabolite · Amphibian disease · BioaugmentationResale or republication not permitted without written consent of the publisher

show abstract

“…int-res. com/ articles/ suppl/ d103 p077_supp.pdf) are in line with those found on frogs in other studies (Woodhams et al 2007b, Walke et al 2011.…”

Section: Discussionsupporting

confidence: 80%

Section: Introductionmentioning

confidence: 99%

Screening bacterial metabolites for inhibitory effects against Batrachochytrium dendrobatidis using a spectrophotometric assay

Bell¹,

Alford²,

Garland³

et al. 2013

Dis. Aquat. Org.

View full text Add to dashboard Cite

show abstract

“…were the most widespread in both our study and a previously published study (28). Several ecological and physiological factors could explain this relationship, including (i) their ability to utilize available glucose (50) or to produce siderophores (51), both of which would reduce resource availability for competitors, as well as (ii) selection by the host for pseudomonads given their capacity to produce numerous antimicrobial compounds (52,53). If generalist anti-B.…”

Section: Discussionmentioning

confidence: 87%

Antifungal Bacteria on Woodland Salamander Skin Exhibit High Taxonomic Diversity and Geographic Variability

Muletz‐Wolz

DiRenzo

Yarwood³

et al. 2017

Appl Environ Microbiol

View full text Add to dashboard Cite

Diverse bacteria inhabit amphibian skin; some of those bacteria inhibit growth of the fungal pathogen Batrachochytrium dendrobatidis. Yet there has been no systematic survey of anti-B. dendrobatidis bacteria across localities, species, and elevations. This is important given geographic and taxonomic variations in amphibian susceptibility to B. dendrobatidis. Our collection sites were at locations within the Appalachian Mountains where previous sampling had indicated low B. dendrobatidis prevalence. We determined the numbers and identities of anti-B. dendrobatidis bacteria on 61 Plethodon salamanders (37 P. cinereus, 15 P. glutinosus, 9 P. cylindraceus) via culturing methods and 16S rRNA gene sequencing. We sampled co-occurring species at three localities and sampled P. cinereus along an elevational gradient (700 to 1,000 meters above sea level [masl]) at one locality. We identified 50 anti-B. dendrobatidis bacterial operational taxonomic units (OTUs) and found that the degree of B. dendrobatidis inhibition was not correlated with relatedness. Five anti-B. dendrobatidis bacterial strains occurred on multiple amphibian species at multiple localities, but none were shared among all species and localities. The prevalence of anti-B. dendrobatidis bacteria was higher at Shenandoah National Park (NP), VA, with 96% (25/26) of salamanders hosting at least one anti-B. dendrobatidis bacterial species compared to 50% (7/14) at Catoctin Mountain Park (MP), MD, and 38% (8/21) at Mt. Rogers National Recreation Area (NRA), VA. At the individual level, salamanders at Shenandoah NP had more anti-B. dendrobatidis bacteria per individual ( ϭ 3.3) than those at Catoctin MP ( ϭ 0.8) and at Mt. Rogers NRA ( ϭ 0.4). All salamanders tested negative for B. dendrobatidis. Anti-B. dendrobatidis bacterial species are diverse in central Appalachian Plethodon salamanders, and their distribution varied geographically. The antifungal bacterial species that we identified may play a protective role for these salamanders.IMPORTANCE Amphibians harbor skin bacteria that can kill an amphibian fungal pathogen, Batrachochytrium dendrobatidis. Some amphibians die from B. dendrobatidis infection, whereas others do not. The bacteria that can kill B. dendrobatidis, called anti-B. dendrobatidis bacteria, are thought to influence the B. dendrobatidis infection outcome for the amphibian. Yet how anti-B. dendrobatidis bacterial species vary among amphibian species and populations is unknown. We determined the distribution of anti-B. dendrobatidis bacterial species among three salamander species (n ϭ 61) sampled at three localities. We identified 50 unique anti-B. dendrobatidis bacterial species and found that all of the tested salamanders were negative for B. dendrobatidis. Five anti-B. dendrobatidis bacterial species were commonly detected, suggesting a stable, functional association with these salamanders. The number of

show abstract

“…For some amphibian species, the microbial environment is manipulated before they emerge from the egg. Evidence of transmission of antifungal bacteria from adult to egg has been observed for the glass frog Hyalinobatrachium colymbiphyllum (Walke et al, 2011) and the salamanders Plethodon cinereus and Hemidactylium scutatum (Brucker et al, 2008;Banning et al, 2008). These examples suggest that the assembly of microbial symbionts in early life stages may have adaptive significance for adult host health.…”

Section: Introductionmentioning

confidence: 86%

Inhibitory bacteria reduce fungi on early life stages of endangered Colorado boreal toads (Anaxyrus boreas)

et al. 2015

View full text Add to dashboard Cite

Increasingly, host-associated microbiota are recognized to mediate pathogen establishment, providing new ecological perspectives on health and disease. Amphibian skin-associated microbiota interact with the fungal pathogen, Batrachochytrium dendrobatidis (Bd), but little is known about microbial turnover during host development and associations with host immune function. We surveyed skin microbiota of Colorado's endangered boreal toads (Anaxyrus boreas), sampling 181 toads across four life stages (tadpoles, metamorphs, subadults and adults). Our goals were to (1) understand variation in microbial community structure among individuals and sites, (2) characterize shifts in communities during development and (3) examine the prevalence and abundance of known Bd-inhibitory bacteria. We used high-throughput 16S and 18S rRNA gene sequencing (Illumina MiSeq) to characterize bacteria and microeukaryotes, respectively. Life stage had the largest effect on the toad skin microbial community, and site and Bd presence also contributed. Proteobacteria dominated tadpole microbial communities, but were later replaced by Actinobacteria. Microeukaryotes on tadpoles were dominated by the classes Alveolata and Stramenopiles, while fungal groups replaced these groups after metamorphosis. Using a novel database of Bd-inhibitory bacteria, we found fewer Bd-inhibitory bacteria in post-metamorphic stages correlated with increased skin fungi, suggesting that bacteria have a strong role in early developmental stages and reduce skinassociated fungi.

show abstract

Social Immunity in Amphibians: Evidence for Vertical Transmission of Innate Defenses

Cited by 101 publications

References 43 publications

Screening bacterial metabolites for inhibitory effects against Batrachochytrium dendrobatidis using a spectrophotometric assay

Screening bacterial metabolites for inhibitory effects against Batrachochytrium dendrobatidis using a spectrophotometric assay

Antifungal Bacteria on Woodland Salamander Skin Exhibit High Taxonomic Diversity and Geographic Variability

Inhibitory bacteria reduce fungi on early life stages of endangered Colorado boreal toads (Anaxyrus boreas)

Contact Info

Product

Resources

About