Microbiology Commons^™

Human Microbiome Transfer In The Built Environment Differs Based On Occupants, Objects, And Buildings, Andrew J. Hoisington, Christopher E. Stamper, Katherine L. Bates, Maggie A. Stanislawski, Michael C. Flux, Teodor T. Postolache, Christopher A. Lowry, Lisa A. Brenner

Faculty Publications

Compared to microbiomes on other skin sites, the bacterial microbiome of the human hand has been found to have greater variability across time. To increase understanding regarding the longitudinal transfer of the hand microbiome to objects in the built environment, and vice versa, 22 participants provided skin microbiome samples from their dominant hands, as well as from frequently and infrequently touched objects in their office environments. Additional longitudinal samples from home environments were obtained from a subset of 11 participants. We observed stability of the microbiomes of both the hand and built environments within the office and home settings; however, …

Hematophagy And Tick-Borne Rickettsial Pathogen Shape The Microbial Community Structure And Predicted Functions Within The Tick Vector, Amblyomma Maculatum., Abdulsalam Adegoke, Deepak Kumar, Khemraj Budachetri, Shahid Karim

Faculty Publications

Background: Ticks are the primary vectors of emerging and resurging pathogens of public health significance worldwide. Analyzing tick bacterial composition, diversity, and functionality across developmental stages and tissues is crucial for designing new strategies to control ticks and prevent tick-borne diseases.

Materials and methods: Here, we explored the microbial communities across the developmental timeline and in different tissues of the Gulf-Coast ticks (Amblyomma maculatum). Using a high-throughput sequencing approach, the influence of blood meal and Rickettsia parkeri, a spotted fever group rickettsiae infection in driving changes in microbiome composition, diversity, and functionality was determined.

Results: This study …

Rickettsia Parkeri Infection Modulates The Sialome And Ovariome Of The Gulf Coast Tick, Amblyomma Maculatum, Melina Garcia Guizzo, Khemraj Budachetri, Abdulsalam Adegoke, Jose M.C. Ribeiro, Shahid Karim

Faculty Publications

The Gulf Coast tick, Amblyomma maculatum, is a vector of several tick-borne pathogens, including Rickettsia parkeri. The ability of R. parkeri to persist within the tick population through transovarial and transstadial transmission, without apparently harming the ticks, contributes to the pathogen’s perpetuation in the tick population. Previous studies have shown that the R. parkeri load in A. maculatum is regulated by the tick tissues’ oxidant/antioxidant balance and the non-pathogenic tick microbiome. To obtain further insights into the interaction between tick and pathogen, we performed a bulk RNA-Seq for differential transcriptomic analysis of ovaries and salivary …

Sorption Of Cellulases In Biofilm Enhances Cellulose Degradation By Bacillus Subtilis, Yijie Deng, Shiao Y. Wang

Faculty Publications

Biofilm commonly forms on the surfaces of cellulosic biomass but its roles in cellulose degradation remain largely unexplored. We used Bacillus subtilis to study possible mechanisms and the contributions of two major biofilm components, extracellular polysaccharides (EPS) and TasA protein, to submerged biofilm formation on cellulose and its degradation. We found that biofilm produced by B. subtilis is able to absorb exogenous cellulase added to the culture medium and also retain self-produced cellulase within the biofilm matrix. The bacteria that produced more biofilm degraded more cellulose compared to strains that produced less biofilm. Knockout strains that lacked both EPS and …

Delineating The Role Of The Msaabcr Operon In Staphylococcal Overflow Metabolism, Gc Bibek, Gyan S. Sahukhal, Mohamed O. Elasri

Faculty Publications

Staphylococcus aureus is an important human pathogen that can infect almost every organ system, resulting in a high incidence of morbidity and mortality. The msaABCR operon is an important regulator of several staphylococcal phenotypes, including biofilm development, cell wall crosslinking, antibiotic resistance, oxidative stress, and acute and chronic implant-associated osteomyelitis. Our previous study showed that, by modulating murein hydrolase activity, the msaABCR operon negatively regulates the proteases that govern cell death. Here, we report further elucidation of the mechanism of cell death, which is regulated by the msaABCR operon at the molecular level in the USA300 LAC strain. We showed …

High Level Of Persister Frequency In Clinical Staphylococcal Isolates, Sarita Manandhar, Anjana Singh, Ajit Varma, Shanti Pandey, Neeraj Shrivastava

Faculty Publications

Staphylococcus aureus is a notorious human pathogen that causes often lethal systemic conditions that are mostly medical device associated biofilm infections. Similarly, coagulase negative staphylococci are emerging as leading pathogen for nosocomial infections owing to their ability to form biofilm on implanted medical equipment. Chronic in nature, these infections are difficult to treat. Such recalcitrance of these infections is caused mainly due to the presence of persister cells, which exhibit transient yet extreme tolerance to antibiotics. Despite tremendous clinical significance, there is lack of studies on persister cells formation among clinical bacterial isolates. Considering the importance of factors influencing persister …

Recently Evolved Francisella-Like Endosymbiont Outcompetes An Ancient And Evolutionarily Associated Coxiella-Like Endosymbiont In The Lone Star Tick (Amblyomma Americanum) Linked To The Alpha-Gal Syndrome, Deepak Kumar, Surendra Raj Sharma, Abdulsalam Adegoke, Ashley Kennedy, Holly C. Tuten, Andrew Y. Li, Shahid Karim

Faculty Publications

Background: Ticks are hematophagous arthropods that transmit various bacterial, viral, and protozoan pathogens of public health significance. The lone star tick (Amblyomma americanum) is an aggressive human-biting tick that transmits bacterial and viral pathogens, and its bites are suspected of eliciting the alpha-gal syndrome, a newly emerged delayed hypersensitivity following consumption of red meat in the United States. While ongoing studies have attempted to investigate the contribution of different tick-inherent factors to the induction of alpha-gal syndrome, an otherwise understudied aspect is the contribution of the tick microbiome and specifically obligate endosymbionts to the establishment of the alpha-gal …

An Insight Into The Microrna Profile Of The Ectoparasitic Mite Varroa Destructor (Acari: Varroidae), The Primary Vector Of Honey Bee Deformed Wing Virus, Deepak Kumar, Mohamed Alburaki, Faizan Tahir, Michael Goblirsch, John Adamczyk, Shahid Karim

Faculty Publications

The remarkably adaptive mite Varroa destructor is the most important honey bee ectoparasite. Varroa mites are competent vectors of deformed wing virus (DWV), and the Varroa-virus complex is a major determinant of annual honey bee colony mortality and collapse. MicroRNAs (miRNAs) are 22-24 nucleotide non-coding RNAs produced by all plants and animals and some viruses that influence biological processes through post-transcriptional regulation of gene expression. Knowledge of miRNAs and their function in mite biology remains limited. Here we constructed small RNA libraries from male and female V. destructor using Illumina’s small RNA-Seq platform. A total of 101,913,208 and 91,904,732 …

An Exploratory Study On The Microbiome Of Northern And Southern Populations Of Ixodes Scapularis Ticks Predicts Changes And Unique Bacterial Interactions, Deepak Kumar, Latoyia P. Downs, Abdulsalam Adegoke, Erika Machtinger, Kelly Oggenfuss, Richard S. Ostfeld, Monica Embers, Shahid Karim

Faculty Publications

The black-legged tick (Ixodes scapularis) is the primary vector of Borrelia burgdorferi, the causative agent of Lyme disease in North America. However, the prevalence of Lyme borreliosis is clustered around the Northern States of the United States of America. This study utilized a metagenomic sequencing approach to compare the microbial communities residing within Ix. scapularis populations from northern and southern geographic locations in the USA. Using a SparCC network construction model, we performed potential interactions between members of the microbial communities from Borrelia burgdorferi–infected tissues of unfed and blood-fed ticks. A significant difference in bacterial composition …

The Seasonal Flux And Fate Of Dissolved Organic Carbon Through Bacterioplankton In The Western North Atlantic, Nicholas Baetge, Michael J. Behrenfeld, James Fox, Kimberly H. Halsey, Kristina D.A. Mojica, Anai Novoa, Brandon M. Stephens, Craig A. Carlson

Faculty Publications

The oceans teem with heterotrophic bacterioplankton that play an appreciable role in the uptake of dissolved organic carbon (DOC) derived from phytoplankton net primary production (NPP). As such, bacterioplankton carbon demand (BCD), or gross heterotrophic production, represents a major carbon pathway that influences the seasonal accumulation of DOC in the surface ocean and, subsequently, the potential vertical or horizontal export of seasonally accumulated DOC. Here, we examine the contributions of bacterioplankton and DOM to ecological and biogeochemical carbon flow pathways, including those of the microbial loop and the biological carbon pump, in the Western North Atlantic Ocean (∼39–54°N along ∼40°W) …

Increased Antimicrobial And Multidrug Resistance Downstream Of Wastewater Treatment Plants In An Urban Watershed, Maitreyee Mukherjee, Edward Laird, Terry J. Gentry, John P. Brooks, Raghupathy Karthikeyan

Faculty Publications

Development and spread of antimicrobial resistance (AMR) and multidrug resistance (MDR) through propagation of antibiotic resistance genes (ARG) in various environments is a global emerging public health concern. The role of wastewater treatment plants (WWTPs) as hot spots for the dissemination of AMR and MDR has been widely pointed out by the scientific community. In this study, we collected surface water samples from sites upstream and downstream of two WWTP discharge points in an urban watershed in the Bryan-College Station (BCS), Texas area, over a period of nine months. E. coli isolates were tested for resistance to ampicillin, tetracycline, sulfamethoxazole, …

Elevated Incidences Of Antimicrobial Resistance And Multidrug Resistance In The Maumee River (Ohio, Usa), A Major Tributary Of Lake Erie, Maitreyee Mukherjee, Leah Marie, Cheyenne Liles, Nadia Mustafa, George Bullerjahn, Terry J. Gentry, John P. Brooks

Faculty Publications

Maumee River, the major tributary in the western basin of Lake Erie, serves as one of major sources of freshwater in the area, supplying potable, recreational, and industrial water. In this study we collected water samples from four sites in the Maumee River Bay between 2016–2017 and E. coli was isolated, enumerated, and analyzed for antimicrobial resistance (AMR) and multidrug resistance (MDR). Strikingly, 95% of the total isolates were found to be resistant to at least one antibiotic. A very high resistance to the drugs cephalothin (95.3%), ampicillin (38.3%), tetracycline (8.8%), gentamicin (8.2%), ciprofloxacin (4.2%), cefoperazone (4%), and sulfamethoxazole (1.5%) …

The Msaabcr Operon Regulates Persister Formation By Modulating Energy Metabolism In Staphylococcus Aureus, Shanti Pandey, Gyan S. Sahukhal, Mohamed O. Elasri

Faculty Publications

Staphylococcus aureus is a major human pathogen that causes chronic, systemic infections, and the recalcitrance of these infections is mainly due to the presence of persister cells, which are a bacterial subpopulation that exhibits extreme, yet transient, antibiotic tolerance accompanied by a transient halt in growth. However, upon cessation of antibiotic treatment, a resumption in growth of persister cells causes recurrence of infections and treatment failure. Previously, we reported the involvement of msaABCR in several important staphylococcal phenotypes, including the formation of persister cells. Additionally, observations of the regulation of several metabolic genes by the msaABCR operon in transcriptomics and …

Root Exudates Alter The Expression Of Diverse Metabolic, Transport, Regulatory, And Stress Response Genes In Rhizosphere Pseudomonas, Olga V. Mavrodi, Janiece R. Mcwilliams, Jacob O. Peter, Anna Berim, Karl A. Hassan, Liam D.H. Elbourne, Melissa K. Letourneau, David R. Gang, Ian T. Paulsen, David M. Weller, Linda S. Thomashow, Alex S. Flynt, Dmitri V. Mavrodi

Faculty Publications

Plants live in association with microorganisms that positively influence plant development, vigor, and fitness in response to pathogens and abiotic stressors. The bulk of the plant microbiome is concentrated belowground at the plant root-soil interface. Plant roots secrete carbon-rich rhizodeposits containing primary and secondary low molecular weight metabolites, lysates, and mucilages. These exudates provide nutrients for soil microorganisms and modulate their affinity to host plants, but molecular details of this process are largely unresolved. We addressed this gap by focusing on the molecular dialog between eight well-characterized beneficial strains of the Pseudomonas fluorescens group and Brachypodium distachyon, a model …

Microbial Functional Responses In Marine Biofilms Exposed To Deepwater Horizon Spill Contaminants, Rachel L. Mugge, Jennifer L. Salerno, Leila J. Hamdan

Faculty Publications

Marine biofilms are essential biological components that transform built structures into artificial reefs. Anthropogenic contaminants released into the marine environment, such as crude oil and chemical dispersant from an oil spill, may disrupt the diversity and function of these foundational biofilms. To investigate the response of marine biofilm microbiomes from distinct environments to contaminants and to address microbial functional response, biofilm metagenomes were analyzed from two short-term microcosms, one using surface seawater (SSW) and the other using deep seawater (DSW). Following exposure to crude oil, chemical dispersant, and dispersed oil, taxonomically distinct communities were observed between microcosms from different source …

Two Hundred And Fifty-Four Metagenome-Assembled Bacterial Genomes From The Bank Vole Gut Microbiota, Anton Lavrinienko, Eugene Tukalenko, Timothy A. Mousseau, Luke R. Thompson, Rob Knight, Tapio Mappes, Phillip C. Watts

Faculty Publications

Vertebrate gut microbiota provide many essential services to their host. To better understand the diversity of such services provided by gut microbiota in wild rodents, we assembled metagenome shotgun sequence data from a small mammal, the bank vole Myodes glareolus (Rodentia, Cricetidae). We were able to identify 254 metagenome assembled genomes (MAGs) that were at least 50% (n = 133 MAGs), 80% (n = 77 MAGs) or 95% (n = 44 MAGs) complete. As typical for a rodent gut microbiota, these MAGs are dominated by taxa assigned to the phyla Bacteroidetes (n = 132 MAGs) and …

The Role Of The Msaabcr Operon In Implant-Associated Chronic Osteomyelitis In Staphylococcus Aureus Usa300 Lac, Gyan S. Sahukhal, Michelle Tucci, Hamed Benghuzzi, Gerri Wilson, Mohamed O. Elasri

Faculty Publications

The msaABCR operon regulates several staphylococcal phenotypes such as biofilm formation, capsule production, protease production, pigmentation, antibiotic resistance, and persister cells formation. The msaABCR operon is required for maintaining the cell wall integrity via affecting peptidoglycan cross-linking. The msaABCR operon also plays a role in oxidative stress defense mechanism, which is required to facilitate persistent and recurrent staphylococcal infections. Staphylococcus aureus is the most frequent cause of chronic implant-associated osteomyelitis (OM). The CA-MRSA USA300 strains are predominant in the United States and cause severe infections, including bone and joint infections.

Significance Of Viral Activity For Regulating Heterotrophic Prokaryote Community Dynamics Along A Meridional Gradient Of Stratification In The Northeast Atlantic Ocean, Kristina D.A. Mojica, Corina P.D. Brussaard

Faculty Publications

How microbial populations interact influences the availability and flux of organic carbon in the ocean. Understanding how these interactions vary over broad spatial scales is therefore a fundamental aim of microbial oceanography. In this study, we assessed variations in the abundances, production, virus and grazing induced mortality of heterotrophic prokaryotes during summer along a meridional gradient in stratification in the North Atlantic Ocean. Heterotrophic prokaryote abundance and activity varied with phytoplankton biomass, while the relative distribution of prokaryotic subpopulations (ratio of high nucleic acid fluorescent (HNA) and low nucleic acid fluorescent (LNA) cells) was significantly correlated to phytoplankton mortality mode …

Tick-Borne Pathogens Shape The Native Microbiome Within Tick Vectors, Abdulsalam Adegoke, Deepak Kumar, Cailyn Bobo, Muhammad Imran Rashid, Aneela Zameer Durrani, Muhammad Sohail Sajid, Shahid Karim

Faculty Publications

© 2020 by the authors. Licensee MDPI, Basel, Switzerland. Ticks are blood-feeding arthropods and transmit a variety of medically important viral, bacterial, protozoan pathogens to animals and humans. Ticks also harbor a diverse community of microbes linked to their biological processes, such as hematophagy, and hence affect vector competence. The interactions between bacterial and/or protozoan pathogens and the tick microbiome is a black-box, and therefore we tested the hypothesis that the presence of a protozoan or bacterial pathogen will alter the microbial composition within a tick. Hence, this study was designed to define the microbial composition of two tick species, …

Draft Genome Sequences Of Six Strains Isolated From The Rhizosphere Of Wheat Grown In Cadmium-Contaminated Soil, Vira Hovorukha, Ankita Bhattacharyya, Olga Iungin, Hanna Tashyreva, Victoria Romanovska, Olesia Havyrliuk, Olena Bielikova, Claire Blackwell, Brian Burks, Cara Cothern, Jakia Elliott, Jonathan Hoover, Alexis Jones, Christian Leise, Linda Lowmiller, Ahmed Mohamed, Tiffany Mullen, Ethan Nettleton, Karshanda Polk, Benny Tran, Teresa Tran, Manuel Vega, Landon Ware, Emily Welch, Leandra Williams, Madison Woodward, Kaylin Young, Olga Mavrodi, Oleksandr Tashyrev, Dmitri Mavrodi

Faculty Publications

This study presents high-quality draft genome assemblies of six bacterial strains isolated from the roots of wheat grown in soil contaminated with cadmium. The results of this study will help to elucidate at the molecular level how heavy metals affect interactions between beneficial rhizobacteria and crop plants.

Meeting Report Of The Third Annual Tri-Service Microbiome Consortium Symposium, J Philip Karl, Robyn A. Barbato, Laurel A. Doherty, Aarti Gautam, Sarah M. Glaven, Robert J. Kokoska, Dagmar Leary, Rebecca Mickol, Matthew A. Perisin, Andrew J. Hoisington, Edward J. Van Opstal, Vanessa Varaljay, Nancy Kelley-Loughnane, Camilla A. Mauzy, Michael S. Goodson, Jason W. Soares

Faculty Publications

The Tri-Service Microbiome Consortium (TSMC) was founded to enhance collaboration, coordination, and communication of microbiome research among U.S. Department of Defense (DoD) organizations and to facilitate resource, material and information sharing among consortium members. The 2019 annual symposium was held 22–24 October 2019 at Wright-Patterson Air Force Base in Dayton, OH. Presentations and discussions centered on microbiome-related topics within five broad thematic areas: 1) human microbiomes; 2) transitioning products into Warfighter solutions; 3) environmental microbiomes; 4) engineering microbiomes; and 5) microbiome simulation and characterization. Collectively, the symposium provided an update on the scope of current DoD microbiome research efforts, highlighted …

Listeria Monocytogenes Response To Anaerobic Environments, Brandy N. Roberts, Damayanti Chakravarty, J.C. Gardner Iii, Steven C. Ricke, Janet R. Donaldson

Faculty Publications

Listeria monocytogenes is a Gram-positive facultative anaerobic bacterium that is responsible for the disease, listeriosis. It is particularly lethal in pregnant women, the fetus, the elderly and the immunocompromised. The pathogen survives and replicates over a wide range of temperatures (4 to 42 °C), pH, salt and oxygen concentrations. Because it can withstand various environments, L. monocytogenes is a major concern in food processing industries, especially in dairy products and ready-to-eat fruits, vegetables and deli meats. The environment in which the pathogen is exposed can influence the expression of virulence genes. For instance, studies have shown that variations in oxygen …

The Antimicrobial Activity And Cellular Pathways Targeted By P-Anisaldehyde And Epigallocatechin Gallate In The Opportunistic Human Pathogen Pseudomonas Aeruginosa, Yetunde Adewumni, Sanchirmaa Namjilsuren, William D. Walker, Dahlia N. Amato, Douglas V. Amato, Olga V. Mavrodi, Derek L. Patton, Dmitri V. Mavrodi

Faculty Publications

Plant-derived aldehydes are constituents of essential oils that possess broad-spectrum antimicrobial activity and kill microorganisms without promoting resistance. In our previous study, we incorporated p-anisaldehyde from star anise into a polymer network called PANDAs (Pro-Antimicrobial Networks via Degradable Acetals) and used it as a novel drug delivery platform. PANDAs released p-anisaldehyde upon a change in pH and humidity, and controlled growth of the multi-drug resistant pathogen Pseudomonas aeruginosa PAO1. In this study, we identified cellular pathways targeted by p-anisaldehyde, by generating 10,000 transposon mutants of PAO1 and screened them for hypersensitivity to p-anisaldehyde. To improve the …

Analysis Of The Cody Rnome Reveals Rsad As A Stress-Responsive Riboregulator Of Overflow Metabolism In Staphylococcus Aureus, Yoann Augagneur, Alyssa N. King, Noëlla Germain-Amiot, Mohamed Sassi, John W. Fitzgerald, Gyan S. Sahukhal, Mohamed O. Elasri, Brice Felden, Shaun R. Brinsmade

Faculty Publications

In Staphylococcus aureus, the transcription factor CodY modulates the expression of hundreds of genes, including most virulence factors, in response to the availability of key nutrients like GTP and branched‐chain amino acids. Despite numerous studies examining how CodY controls gene expression directly or indirectly, virtually nothing is known about the extent to which CodY exerts its effect through small regulatory RNAs (sRNAs). Herein, we report the first set of sRNAs under the control of CodY. We reveal that staphylococcal sRNA RsaD is overexpressed >20‐fold in a CodY‐deficient strain in three S. aureus clinical isolates and in S. epidermidis. …

Current Understanding Of West Nile Virus Clinical Manifestations, Immune Responses, Neuroinvasion, And Immunotherapeutic Implications, Fengwei Bai, E. Ashley Thompson, Parminder J.S. Vig, A. Arturo Leis

Faculty Publications

West Nile virus (WNV) is the most common mosquito-borne virus in North America. WNV-associated neuroinvasive disease affects all ages, although elderly and immunocompromised individuals are particularly at risk. WNV neuroinvasive disease has killed over 2300 Americans since WNV entered into the United States in the New York City outbreak of 1999. Despite 20 years of intensive laboratory and clinical research, there are still no approved vaccines or antivirals available for human use. However, rapid progress has been made in both understanding the pathogenesis of WNV and treatment in clinical practices. This review summarizes our current understanding of WNV infection in …

Parasitic Microbiome Project: Grand Challenges, Nolwenn M. Dheilly, Joaquín Martínez Martínez, Karyna Rosario, Paul J. Brindley, Raina N. Fichorava, Jonathan Z. Kaye, Kevin D. Kohl, Laura J. Knoll, Julius Lukeš, Susan L. Perkins, Robert Poulin, Lynn Schriml, Luke R. Thompson

Faculty Publications

No abstract provided.

Establishment Of Listeria Monocytogenes In The Gastrointestinal Tract, Morgan L. Davis, Steven C. Ricke, Janet R. Donaldson

Faculty Publications

Listeria monocytogenes is a Gram positive foodborne pathogen that can colonize the gastrointestinal tract of a number of hosts, including humans. These environments contain numerous stressors such as bile, low oxygen and acidic pH, which may impact the level of colonization and persistence of this organism within the GI tract. The ability of L. monocytogenes to establish infections and colonize the gastrointestinal tract is directly related to its ability to overcome these stressors, which is mediated by the efficient expression of several stress response mechanisms during its passage. This review will focus upon how and when this occurs and how …

Host Lipids In Positive-Strand Rna Virus Genome Replication, Zhenlu Zhang, Guijuan He, Natalie A. Filipowicz, Glenn Randall, George A. Belov, Benjamin G. Kopek, Xiaofeng Wang

Faculty Publications

Membrane association is a hallmark of the genome replication of positive-strand RNA viruses [(+)RNA viruses]. All well-studied (+)RNA viruses remodel host membranes and lipid metabolism through orchestrated virus-host interactions to create a suitable microenvironment to survive and thrive in host cells. Recent research has shown that host lipids, as major components of cellular membranes, play key roles in the replication of multiple (+)RNA viruses. This review focuses on how (+)RNA viruses manipulate host lipid synthesis and metabolism to facilitate their genomic RNA replication, and how interference with the cellular lipid metabolism affects viral replication.

Diversity And Shifts Of The Bacterial Community Associated With Baikal Sponge Mass Mortalities, Sergei Belikov, Natalia Belkova, Tatiana Butina, Lubov Chernogor, Alexandra Martynova-Van Kley, Armen Nalian, Colin Rorex, Igor Khanaev, Olga Maikova, Sergey Feranchuk

Faculty Publications

The disease of freshwater sponges was first discovered in 2011, when pink samples were found in the Central Basin of Lake Baikal. Subsequently, the visible signs of the disease have changed, and now sponges appear with various symptoms of damage to the body, such as discoloration, tissue necrosis, the formation of brown patches and dirty-purple biofilms on some branches. These signs of the disease are accompanied by the mass death of sponges. We identified differences in microbiomes by sequencing 16S rRNA genes and found changes in the consortium of microorganisms of freshwater Baikal sponges. We found that the observed imbalance …

A Novel Sparse Compositional Technique Reveals Microbial Perturbations, Cameron Martino, James T. Morton, Clarisse A. Martoz, Luke R. Thompson, Anupriya Tripathi, Rob Knight, Karsten Zengler

Faculty Publications

The central aims of many host or environmental microbiome studies are to elucidate factors associated with microbial community compositions and to relate microbial features to outcomes. However, these aims are often complicated by difficulties stemming from high-dimensionality, non-normality, sparsity, and the compositional nature of microbiome data sets. A key tool in microbiome analysis is beta diversity, defined by the distances between microbial samples. Many different distance metrics have been proposed, all with varying discriminatory power on data with differing characteristics. Here, we propose a compositional beta diversity metric rooted in a centered log-ratio transformation and matrix completion called robust Aitchison …