Validation of key sponge symbiont pathways using genome-centric metatranscriptomics.

The sponge microbiome underpins host function through provision and recycling of essential nutrients in a nutrient poor environment. Genomic data suggest that carbohydrate degradation, carbon fixation, nitrogen metabolism, sulphur metabolism and supplementation of B-vitamins are central microbial functions. However, validation beyond the genomic potential of sponge symbiont pathways is rarely explored. To evaluate metagenomic predictions, we sequenced the metagenomes and metatranscriptomes of three common coral reef sponges: Ircinia ramosa, Ircinia microconulosa and Phyllospongia foliascens. Multiple carbohydrate active enzymes were expressed by Poribacteria, Bacteroidota and Cyanobacteria symbionts, suggesting these lineages have a central role in assimilating dissolved organic matter. Expression of entire pathways for carbon fixation and multiple sulphur compound transformations were observed in all sponges. Gene expression for anaerobic nitrogen metabolism (denitrification and nitrate reduction) were more common than aerobic metabolism (nitrification), where only the I. ramosa microbiome expressed the nitrification pathway. Finally, while expression of the biosynthetic pathways for B-vitamins was common, the expression of additional transporter genes was far more limited. Overall, we highlight consistencies and disparities between metagenomic and metatranscriptomic results when inferring microbial activity, while uncovering new microbial taxa that contribute to the health of their sponge host via nutrient exchange.

STI and HIV testing: examining factors that influence uptake among domestic Australian-born, domestic overseas-born and international tertiary students studying in Australia.

OBJECTIVES: Sexual health knowledge among international students in Australia is lower than domestic students, however, little is known about what factors affect the uptake of STI testing, nor if there are differences for overseas-born domestic students. METHODS: We included sexually active respondents from a survey of university students in Australia (N = 3,075). Multivariate regression and mediation analyses investigated associations of STI and HIV testing with STI and HIV knowledge respectively, sexual risk behaviour and demographics, including comparisons among: domestic Australian-born, domestic overseas-born, and international students. RESULTS: STI and HIV knowledge was positively associated with STI and HIV testing respectively (STI OR = 1.13, 95% CI: 1.09, 1.16; HIV OR = 1.37, 95% CI: 1.27, 1.48). STI knowledge was significantly lower for international than domestic Australian-born students (10.8 vs. 12.2 out of 16), as was STI testing (32% vs. 38%); the difference in knowledge accounted for half the difference in STI testing rates between these two groups. International students from Southern Asia, and Eastern Asia reported the lowest STI testing rates. HIV testing was highest amongst international students from Africa and North America. Higher sexual risk behaviour, younger age, and identifying as gay or bisexual were positively associated with higher STI and HIV testing rates. CONCLUSIONS: Our study supports greater investment and commitment by universities for the provision of sexual health education that can promote access to testing to improve the health of their students.

Characterization of Influenza-Like Illness Burden Using Commercial Wearable Sensor Data and Patient-Reported Outcomes: Mixed Methods Cohort Study.

BACKGROUND: The burden of influenza-like illness (ILI) is typically estimated via hospitalizations and deaths. However, ILI-associated morbidity that does not require hospitalization remains poorly characterized. OBJECTIVE: The main objective of this study was to characterize ILI burden using commercial wearable sensor data and investigate the extent to which these data correlate with self-reported illness severity and duration. Furthermore, we aimed to determine whether ILI-associated changes in wearable sensor data differed between care-seeking and non-care-seeking populations as well as between those with confirmed influenza infection and those with ILI symptoms only. METHODS: This study comprised participants enrolled in either the FluStudy2020 or the Home Testing of Respiratory Illness (HTRI) study; both studies were similar in design and conducted between December 2019 and October 2020 in the United States. The participants self-reported ILI-related symptoms and health care-seeking behaviors via daily, biweekly, and monthly surveys. Wearable sensor data were recorded for 120 and 150 days for FluStudy2020 and HTRI, respectively. The following features were assessed: total daily steps, active time (time spent with >50 steps per minute), sleep duration, sleep efficiency, and resting heart rate. ILI-related changes in wearable sensor data were compared between the participants who sought health care and those who did not and between the participants who tested positive for influenza and those with symptoms only. Correlative analyses were performed between wearable sensor data and patient-reported outcomes. RESULTS: After combining the FluStudy2020 and HTRI data sets, the final ILI population comprised 2435 participants. Compared with healthy days (baseline), the participants with ILI exhibited significantly reduced total daily steps, active time, and sleep efficiency as well as increased sleep duration and resting heart rate. Deviations from baseline typically began before symptom onset and were greater in the participants who sought health care than in those who did not and greater in the participants who tested positive for influenza than in those with symptoms only. During an ILI event, changes in wearable sensor data consistently varied with those in patient-reported outcomes. CONCLUSIONS: Our results underscore the potential of wearable sensors to discriminate not only between individuals with and without influenza infections but also between care-seeking and non-care-seeking populations, which may have future application in health care resource planning. TRIAL REGISTRATION: Clinicaltrials.gov NCT04245800; https://clinicaltrials.gov/ct2/show/NCT04245800.

Rethinking referral pathways: qualitative evaluation of general practice networks to increase access to intrauterine contraception.

BACKGROUND: Long-acting reversible contraceptives are recommended first-line contraception; however, intrauterine device (IUD) uptake remains low in Australia. OBJECTIVES: To describe the outcomes of an independent evaluation of the General Practitioner IUD Insertion Network (GPIIN), a project designed to address access barriers through formalized referral pathways between general practitioners (GPs) inserting IUDs and noninserters. METHODS: An independent qualitative pragmatic inductive evaluation, involving 14 in-depth interviews with GPIIN members, was conducted 18 months post-GPIIN implementation in 2 Australian jurisdictions to identify and explore critical success factors and limitations of the model. RESULTS: Local GP-to-GP IUD referral networks were considered a useful model to assist affordable and timely IUD access, improve noninserters' IUD knowledge and inserters' reflection on best practice. However, pathway simplification is needed to determine optimal integration of the concept into pragmatic GP-to-GP referral arrangements. CONCLUSIONS: GPIIN provides an opportunity to improve IUD access in Primary Health Care. Further consideration of organizations best positioned and resourced to facilitate sustainable delivery and coordination is necessary.

STI and HIV knowledge and testing: a comparison of domestic Australian-born, domestic overseas-born and international university students in Australia.

University students usually consist of young people from culturally and linguistically diverse backgrounds, and a group recognised as being at increased risk of STI. This study found lower levels of STI knowledge and STI testing among international students and to a lesser extent, domestic overseas-born students, compared with domestic Australian-born students. International students exhibited lower risk sexual behaviour but were more likely to have had a HIV test than domestic students. This diversity in sexual health knowledge, sexual health services utilisation and sexual experience indicates the need for a variety of public health approaches to improve sexual health.

Single-Cell Classification Using Mass Spectrometry through Interpretable Machine Learning.

The brain consists of organized ensembles of cells that exhibit distinct morphologies, cellular connectivity, and dynamic biochemistries that control the executive functions of an organism. However, the relationships between chemical heterogeneity, cell function, and phenotype are not always understood. Recent advancements in matrix-assisted laser desorption/ionization mass spectrometry have enabled the high-throughput, multiplexed chemical analysis of single cells, capable of resolving hundreds of molecules in each mass spectrum. We developed a machine learning workflow to classify single cells according to their mass spectra based on cell groups of interest (GOI), e.g., neurons vs astrocytes. Three data sets from various cell groups were acquired on three different mass spectrometer platforms representing thousands of individual cell spectra that were collected and used to validate the single cell classification workflow. The trained models achieved >80% classification accuracy and were subjected to the recently developed instance-based model interpretation framework, SHapley Additive exPlanations (SHAP), which locally assigns feature importance for each single-cell spectrum. SHAP values were used for both local and global interpretations of our data sets, preserving the chemical heterogeneity uncovered by the single-cell analysis while offering the ability to perform supervised analysis. The top contributing mass features to each of the GOI were ranked and selected using mean absolute SHAP values, highlighting the features that are specific to the defined GOI. Our approach provides insight into discriminating the chemical profiles of the single cells through interpretable machine learning, facilitating downstream analysis and validation.

Connectivity over a disease risk gradient enables recovery of rainforest frogs.

Chytridiomycosis has been a key driver of global frog declines and extinctions, particularly for high-altitude populations across Australia and the Americas. While recent evidence shows some species are recovering, the extent of such recoveries and the mechanisms underpinning them remain poorly resolved. We surveyed the historical latitudinal and elevational range of four Australian rainforest frogs that disappeared from upland sites between 1989 and 1994 to establish their contemporary distribution and elevational limits, and investigate factors affecting population recovery. Five rainforest streams were surveyed from mountain-base to summit (30 sites in total), with swabs collected from the target species (Litoria dayi, L. nannotis, L. rheocola, and L. serrata) to determine their infection status, and data loggers deployed to measure microclimatic variation across the elevational gradient. Infection probability increased with elevation and canopy cover as it was tightly and inversely correlated with stream-side air temperature. Occupancy patterns suggest varying responses to this disease threat gradient. Two species, L. rheocola and L. serrata, were found over their full historical elevational range (≥1,000 m above sea level [asl]), while L. dayi was not detected above 400 m (formerly known up to 900 m asl) and L. nannotis was not detected above 800 m (formerly known up to 1,200 m asl). Site occupancy probability was negatively related to predicted infection prevalence for L. dayi, L. nannotis, and L. rheocola, but not L. serrata, which appears to now tolerate high fungal burdens. This study highlights the importance of environmental refuges and connectivity across disease risk gradients for the persistence and natural recovery of frogs susceptible to chytridiomycosis. Likewise, in documenting both interspecific variation in recovery rates and intraspecific differences between sites, this study suggests interactions between disease threats and host selection exist that could be manipulated. For example, translocations may be warranted where connectivity is poor or the increase in disease risk is too steep to allow recolonization, combined with assisted selection or use of founders from populations that have already undergone natural selection.

Peer-delivered point-of-care testing for Chlamydia trachomatis and Neisseria gonorrhoeae within an urban community setting: a cross-sectional analysis.

Background The advent of fully automated nucleic acid amplification test (NAAT) technology brings new public health opportunities to provide Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) point-of-care testing (POCT) in non-traditional settings. METHODS: This pilot study evaluated the integration of the CT/NG Xpert diagnostic assay into an urban peer-led community setting providing HIV and syphilis POCT. A comprehensive protocol of testing, result notification, referral and follow up, managed by peer test facilitators, was undertaken. RESULTS: Over 67 weeks, there were 4523 occasions of CT/NG testing using urine, oropharyngeal and anorectal samples with 25.7% (803) of the 3123 unique participants returning for repeat testing. The prevalence of CT and NG was 9.5% and 5.4% respectively. Where CT and or NG infection was detected, 98.4% (604/614) of participants were successfully notified of detected infection and referred for treatment. Evaluation Survey responses (11.4%, 516/4523) indicated a substantial proportion of respondents (27.1%, 140/516) 'would not have tested anywhere else'. Of note, 17.8% (92/516) of participants reported no previous CT/NG test and an additional 17.8% (92/516) reported testing more than 12 months ago. A total of 95.9% (495/516) of participants 'Strongly agreed' or 'Agreed' to being satisfied with the service. CONCLUSION: The project successfully demonstrated an acceptable and feasible model for a peer-delivered community-led service to provide targeted molecular CT/NG POCT. This model offers capacity to move beyond the traditional pathology and STI testing services and establish community-led models that build trust and increase testing rates for key populations of epidemiological significance.

Reduced sensitivity from pooled urine, pharyngeal and rectal specimens when using a molecular assay for the detection of chlamydia and gonorrhoea near the point of care.

Background The aim of this study was to compare the performance of pooled self-collected urogenital, pharyngeal and anorectal specimens to that of individual specimen results for the molecular detection of Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) near the point of care (POC) for diagnostic sensitivity. METHODS: Clients (mostly men who have sex with men) attending an urban community testing service and three sex-on-premises venues in Brisbane, Australia, were offered CT and NG testing by trained lay providers. Participants provided three self-collected specimens (urine, pharyngeal and rectal) for testing by GeneXpert (Cepheid, Sunnyvale, CA, USA). If any of the individual specimens from a participant were positive, all three specimens were pooled and retested. RESULTS: Of the 388 participants who provided three individual anatomical specimens, 76 (19.6%) were found to be positive for CT and/or NG at one or more sites. The pooling approach failed to detect five CT rectal and four NG pharyngeal infections. The overall performance (sensitivity) of the pooling approach compared with individual specimen testing and Cohen's κ were 90.0% and 0.86 respectively for CT and 89.7% and 0.89 respectively for NG. CONCLUSIONS: Reduced sensitivity was observed when using pooled specimens for the detection of CT and NG using GeneXpert near the POC, similar to results reported in laboratory-based CT and NG pooling studies. These data suggest specimen pooling is feasible near to the POC, potentially saving time and costs when screening at-risk populations for CT and NG. Our data also suggest a reduction in pooled urine could improve overall test sensitivity.

Integrated HIV self-testing (HIVST) service delivery in Queensland for policy and service development: study protocol.

This study aims to pilot and evaluate an integrated model for HIV self-testing (HIVST) service delivery in a peer-led Queensland community setting to increase access to HIVST, particularly for men who have sex with men (MSM) living in regional, remote and rural areas. It seeks to provide evidence that would overcome some of the key objections previously raised to HIVST. Recruitment strategies have been designed to engage hard to reach MSM populations in testing. Awareness of the trial will be generated through advertising on social media platforms, including dating applications, word of mouth and HIV related websites. Participants will access an HIVST online ordering system hosted by a HIV community organisation. This system: (1) enables on-line informed consent; 2) gives clients the choice to accept verbal pre-test information from a trained peer test facilitator or not; and (3) allows for ordering of the HIVST kit after completion of an online survey (with demographic information and testing history etc.). Clients receive the kits via the post; and at 2 weeks receive a follow-up phone-call and SMS link to a post-test survey. If the test is non-reactive, clients can opt for test reminders. If reactive, referral to clinical services, peer navigation and support systems are provided. This study addresses important gaps in understanding of acceptable and feasible methods to integrate HIVST into an existing peer-led testing service and into the broader suite of HIV testing options and services. The findings will inform the actions needed to enhance access to HIVST for MSM wishing to use this technology in Australia and elsewhere, especially those who have never tested and infrequent testers.

Reef invertebrate viromics: diversity, host specificity and functional capacity.

Recent metagenomic analyses have revealed a high diversity of viruses in the pelagic ocean and uncovered clear habitat-specific viral distribution patterns. Conversely, similar insights into the composition, host specificity and function of viruses associated with marine organisms have been limited by challenges associated with sampling and computational analysis. Here, we performed targeted viromic analysis of six coral reef invertebrate species and their surrounding seawater to deliver taxonomic and functional profiles of viruses associated with reef organisms. Sponges and corals' host species-specific viral assemblages with low sequence identity to known viral genomes. While core viral genes involved in capsid formation, tail structure and infection mechanisms were observed across all reef samples, auxiliary genes including those involved in herbicide resistance and viral pathogenesis pathways such as host immune suppression were differentially enriched in reef hosts. Utilising a novel OTU based assessment, we also show a prevalence of dsDNA viruses belonging to the Mimiviridae, Caudovirales and Phycodnaviridae in reef environments and further highlight the abundance of ssDNA viruses belonging to the Circoviridae, Parvoviridae, Bidnaviridae and Microviridae in reef invertebrates. These insights into coral reef viruses provide an important framework for future research into how viruses contribute to the health and evolution of reef organisms.

Integrated approach to understanding the onset and pathogenesis of black band disease in corals.

Emerging infectious diseases are contributing to global declines in coral reef ecosystems, highlighting a growing need for aetiological knowledge to develop effective management strategies. In this review, we focus on black band disease (BBD), one of the most virulent diseases and the only polymicrobial disease so far known to affect corals. A multipartite microbial consortium dominated by Cyanobacteria, but also including sulfur-cycling bacteria, other bacterial groups and members of the Archaea and Eukarya, forms a sulfide-rich anaerobic mat that migrates across the surface of coral colonies, killing the underlying tissues. The polymicrobial nature of the disease challenges classic aetiological approaches to unravelling disease causation. Here, we synthesize current knowledge on the range of pathogens forming the microbial consortium with recent studies on the transmission, biogeochemistry and environmental drivers of BBD to develop a conceptual model of BBD pathogenesis. The model illustrates how the development of BBD virulence factors is linked to a cascade of microbial community shifts and associated functional roles that progressively develop the microbial consortium from comparatively benign cyanobacterial patches to virulent BBD lesions. This review showcases how an approach that integrates multiple key aspects of the disease provides insights essential to elucidating the aetiology of BBD.

Endemicity of chytridiomycosis features pathogen overdispersion.

Pathogens can be critical drivers of the abundance and distribution of wild animal populations. The presence of an overdispersed pathogen load distribution between hosts (where few hosts harbour heavy parasite burdens and light infections are common) can have an important stabilizing effect on host-pathogen dynamics where infection intensity determines pathogenicity. This may potentially lead to endemicity of an introduced pathogen rather than extirpation of the host and/or pathogen. Overdispersed pathogen load distributions have rarely been considered in wild animal populations as an important component of the infection dynamics of microparasites such as bacteria, viruses, protozoa and fungi. Here we examined the abundance, distribution and transmission of the model fungal pathogen Batrachochytrium dendrobatidis (Bd, cause of amphibian chytridiomycosis) between wild-caught Litoria rheocola (common mist frogs) to investigate the effects of an overdispersed pathogen load distribution on the host population in the wild. We quantified host survival, infection incidence and recovery probabilities relative to infectious burden, and compared the results of models where pathogen overdispersion either was or was not considered an important feature of host-pathogen dynamics. We found the distribution of Bd load between hosts to be highly overdispersed. We found that host survival was related to infection burden and that accounting for pathogen overdispersion allowed us to better understand infection dynamics and their implications for disease control. In addition, we found that the pattern of host infections and recoveries varied markedly with season whereby (i) infections established more in winter, consistent with temperature-dependent effects on fungal growth, and (ii) recoveries (loss of infection) occurred frequently in the field throughout the year but were less likely in winter. Our results suggest that pathogen overdispersion is an important feature of endemic chytridiomycosis and that intensity of infection determines disease impact. These findings have important implications for our understanding of chytridiomycosis dynamics and the application of management strategies for disease mitigation. We recommend quantifying individual infectious burdens rather than infection state where possible in microparasitic diseases.

Cell Density Effects of Frog Skin Bacteria on Their Capacity to Inhibit Growth of the Chytrid Fungus, Batrachochytrium dendrobatidis.

Bacterial symbionts on frog skin can reduce the growth of the chytrid fungus Batrachochytrium dendrobatidis (Bd) through production of inhibitory metabolites. Bacteria can be effective at increasing the resistance of amphibians to chytridiomycosis when added to amphibian skin, and isolates can be screened for production of metabolites that inhibit Bd growth in vitro. However, some bacteria use density-dependent mechanism such as quorum sensing to regulate metabolite production. It is therefore important to consider cell density effects when evaluating bacteria as possible candidates for bioaugmentation. The aim of our study was to evaluate how the density of cutaneous bacteria affects their inhibition of Bd growth in vitro. We sampled cutaneous bacteria isolated from three frog species in the tropical rainforests of northern Queensland, Australia, and selected ten isolates that were inhibitory to Bd in standardised pilot trials. We grew each isolate in liquid culture at a range of initial dilutions, sub-sampled each dilution at a series of times during the first 48 h of growth and measured spectrophotometric absorbance values, cell counts and Bd-inhibitory activity of cell-free supernatants at each time point. The challenge assay results clearly demonstrated that the inhibitory effects of most isolates were density dependent, with relatively low variation among isolates in the minimum cell density needed to inhibit Bd growth. We suggest the use of minimum cell densities and fast-growing candidate isolates to maximise bioaugmentation efforts.

Susceptibility of amphibians to chytridiomycosis is associated with MHC class II conformation.

The pathogenic chytrid fungus Batrachochytrium dendrobatidis (Bd) can cause precipitous population declines in its amphibian hosts. Responses of individuals to infection vary greatly with the capacity of their immune system to respond to the pathogen. We used a combination of comparative and experimental approaches to identify major histocompatibility complex class II (MHC-II) alleles encoding molecules that foster the survival of Bd-infected amphibians. We found that Bd-resistant amphibians across four continents share common amino acids in three binding pockets of the MHC-II antigen-binding groove. Moreover, strong signals of selection acting on these specific sites were evident among all species co-existing with the pathogen. In the laboratory, we experimentally inoculated Australian tree frogs with Bd to test how each binding pocket conformation influences disease resistance. Only the conformation of MHC-II pocket 9 of surviving subjects matched those of Bd-resistant species. This MHC-II conformation thus may determine amphibian resistance to Bd, although other MHC-II binding pockets also may contribute to resistance. Rescuing amphibian biodiversity will depend on our understanding of amphibian immune defence mechanisms against Bd. The identification of adaptive genetic markers for Bd resistance represents an important step forward towards that goal.

A genome-centric view of the role of the Acropora kenti microbiome in coral health and resilience.

Microbial diversity has been extensively explored in reef-building corals. However, the functional roles of coral-associated microorganisms remain poorly elucidated. Here, we recover 191 bacterial and 10 archaeal metagenome-assembled genomes (MAGs) from the coral Acropora kenti (formerly A. tenuis) and adjacent seawater, to identify microbial functions and metabolic interactions within the holobiont. We show that 82 MAGs were specific to the A. kenti holobiont, including members of the Pseudomonadota, Bacteroidota, and Desulfobacterota. A. kenti-specific MAGs displayed significant differences in their genomic features and functional potential relative to seawater-specific MAGs, with a higher prevalence of genes involved in host immune system evasion, nitrogen and carbon fixation, and synthesis of five essential B-vitamins. We find a diversity of A. kenti-specific MAGs encode the biosynthesis of essential amino acids, such as tryptophan, histidine, and lysine, which cannot be de novo synthesised by the host or Symbiodiniaceae. Across a water quality gradient spanning 2° of latitude, A. kenti microbial community composition is correlated to increased temperature and dissolved inorganic nitrogen, with corresponding enrichment in molecular chaperones, nitrate reductases, and a heat-shock protein. We reveal mechanisms of A. kenti-microbiome-symbiosis on the Great Barrier Reef, highlighting the interactions underpinning the health of this keystone holobiont.

A cross-sectional investigation of the factors associated with awareness of PEP and PrEP among Queensland university students.

OBJECTIVE: University creates unique social environments for many young people that can result in behaviour changes that can impact sexual health-related risks and facilitate transmission of HIV. Little is known about HIV knowledge, risk, and awareness of pre-exposure prophylaxis/post-exposure prophylaxis (PrEP/PEP) among Australian university students. METHODS: A 2019 online survey distributed through Queensland universities, using active recruitment/snowball sampling. Descriptive and logistical regression analysis investigated HIV knowledge/risk and PrEP/PEP awareness. RESULTS: Of the 4,291 responses, 60.4% were 20-29 years old, 57.0% identified as heterosexual, and 31.8% were born-overseas. Mean HIV knowledge score was 9.8/12. HIV risk scores were higher among men-who-have-sex-with-men (MSM) (mean=5.2/40) compared to all other sexual behaviours (mean=3.1/40). Logistic regression indicated PrEP and PEP awareness was associated with older age (p<0.05), being non-binary/gender-diverse (p<0.05), and MSM (p<0.05). Lower odds of PrEP awareness were associated with international student status (p<0.05). CONCLUSION: This study highlights the need for future health promotion targeting younger Australians at risk of HIV to increase uptake of PrEP/PEP, particularly among overseas-born young people and those ineligible for appropriate health care in Australia. IMPLICATIONS FOR PUBLIC HEALTH: Addressing these gaps will improve sexual health outcomes for young Australians at risk of HIV and work towards virtual elimination of HIV transmission in Australia.

Mitigating amphibian chytridiomycosis with bioaugmentation: characteristics of effective probiotics and strategies for their selection and use.

Probiotic therapy through bioaugmentation is a feasible disease mitigation strategy based on growing evidence that microbes contribute to host defences of plants and animals. Amphibians are currently threatened by the rapid global spread of the pathogen, Batrachochytrium dendrobatidis (Bd), which causes the disease chytridiomycosis. Bioaugmentation of locally occurring protective bacteria on amphibians has mitigated this disease effectively in laboratory trials and one recent field trial. Areas still naïve to Bd provide an opportunity for conservationists to proactively implement probiotic strategies to prevent further amphibian declines. In areas where Bd is endemic, bioaugmentation can facilitate repatriation of susceptible amphibians currently maintained in assurance colonies. Here, we synthesise the current research in amphibian microbial ecology and bioaugmentation to identify characteristics of effective probiotics in relation to their interactions with Bd, their host, other resident microbes and the environment. To target at-risk species and amphibian communities, we develop sampling strategies and filtering protocols that result in probiotics that inhibit Bd under ecologically relevant conditions and persist on susceptible amphibians. This filtering tool can be used proactively to guide amphibian disease mitigation and can be extended to other taxa threatened by emerging infectious diseases.