I'm an assistant professor of animal and veterinary studies at the University of Maine, Orono, studying how animals get their microbes. I am also the Founder and Lead of the Microbes and Social Equity working group.
The Microbes and Social Equity Working Group was featured in on the American Society for Microbiology (ASM) blog in a piece today: “Microbes and social equity“. The blog post describes the global rise of research, education, and policy surrounding microbiomes and how social policy can influence our exposure to them – for better or worse.
You can read more using the link below to the growing list of contributions to the special collections featured by the scientific journal mSystems; “Special Series: Social Equity as a Means of Resolving Disparities in Microbial Exposure.”
Did you know that camels have three stomach chambers or that they have to throw up their own food in order to digest their food properly? Have you felt excluded from science spaces before? Then this blog post is for you!
Allow me to introduce myself.
My name is Myra, and I am a rising senior at SUNY Stony Brook University, where my major is Ecosystems and Human Impact, with a biology minor. In a nutshell, my major is interdisciplinary with a focus on conservation and ecology within human societies.
If I were to describe my college experience in one word I’d pick “surprises”. I never actually saw myself being a scientist in my middle and high school years. I found it hard to care about abstract concepts or theories that felt so far removed from humanity, particularly minority communities. But, during college I found myself falling in love with environmental studies, and along with it, the beautiful complexities that come with being human in our increasingly anthropogenic world.
At UMaine, we focus on the One Health Initiative, which views the health of humans, animals, and the environment as interconnected. When COVID-19 caused everyone to go into lockdown, I was fortunate to find this farm was looking for crew members, with a focus on food security. While certainly not how I planned to spend the summer of 2020, farming for underserved communities is where I saw how impactful One Health was. Organic farmers commonly use plastic mulch as a popular alternative to pesticides for weed suppression. At my home institution, I lead a project on the impacts of microplastics on earthworm health, an Ecotoxicology lab (students of the lab affectionately gave it the nickname “the Worm lab”). We use earthworm health as an indicator of soil health, which in turn is crucial for crop flourishment. The Worm Lab and farming emboldened me to pursue science and, ergo, look for this REU!
At UMaine, I am a member of the Ishaq Lab where I work on the camel metagenome project. Basically, scientists in Egypt raised camels on different diets, then used samples from their feces to sequence their microbial genome. These microbes live in the camel rumen (part of the camel stomach), and help the camel digest their food. What I do with Dr. Ishaq’s lab is, I perform data analysis on these sequences to see how the microbial gene profile changes with different diets. Camels are essential for transportation and food for the communities that rely on them, so finding the most efficient feed for them is important. Camels also release methane depending on their diet so it’s possible humans could control methane production of camels through their diet.
Being a part of the REU ANEW program for 2021 definitely has been an interesting experience, since it is the first time this program has been conducted virtually. Even though I would have loved to have seen everyone in person and spent time in lovely Orono, Maine, I’m glad for the research opportunity as it has further solidified my love of research and the One Health initiative.
Myra’s poster for the REU Research Symposium, virtual, Aug 13, 2021.
Live discussion date: “Thursday, August 5th, 2021”
Live discussion time: 9:30 AM – 10:30 AM Pacific Time
Microbiomes — environmental, human and other organismal symbionts — are increasingly seen as critical physiological, developmental and ecological mediators within and among living things, and between the latter and our abiotic environments. Therefore, it is no surprise that microbial communities may be altered, depleted or disrupted by social and economic determinants. Social inequality entails concrete alterations and differentiation of microbial communities among social groups, by way of such factors as nutritional access, environmental pollutants or green space availability, often to the detriment of human and ecosystem health. This special session will be organized as a panel discussion with break-out groups in order to provide participants the opportunity to discuss the ways in which social inequity interacts with microbiomes, and how we might intervene as scientists and communities to promote favorable microbiomes while advancing social equality. We hope to generate research questions and actionable items.Panel speakers: Michael Friedman, Naupaka Zimmerman, Justin Stewart, Monica Trujillo, Sue Ishaq, Sierra Jech, Jennifer Bhatnagar, and Ariangela Kozik ESA meeting program: https://www.esa.org/longbeach/
Registration to the ESA meeting is required to attend this event.
Next week kicks off the live events, including with question + answer, discussions, and special sessions being held in real time, for the Ecological Society of America’s annual conference, which is being held virtually this year. Prerecorded presentations are already available on demand.
Can a necromenic nematode serve as a biological Trojan horse for an invasive ant?
Session 1-PS7: Vital Connections in Ecology: Breakthroughs in Understanding Species Interactions
Poster and narration available on demand.
Live discussion: Monday, August 2, 2021, 9:30 AM – 10:30 AM Pacific Time
Abstract:
Background/Question/Methods The invasive European fire ant (Myrmica rubra) threatens native ant species and human health along the coast of Maine, United States. M. rubra mortality has been associated with infection by Pristionchus entomophagus, a necromenic nematode that is hypothesized to transfer pathogenic bacteria acquired from the environment to ant colonies. To investigate this hypothesis, we conducted a series of experiments on nematode-infected ants collected from Mount Desert Island. First, we isolated bacteria cultured from nematodes emerging from M. rubra cadavers and assessed the ability of the nematodes to acquire and transfer environmental bacteria to Galleria mellonella waxworm larvae. Second, we identified bacteria which were potentially transferred from nematodes to infected ant nests on MDI using bacterial community similarity and sequence tracking methods.
Results/Conclusions Multiple bacterial species, including Paenibacillus spp., were found in the nematodes’ digestive tract. Serratia marcescens, Serratia nematodiphila, and Pseudomonas fluorescens were collected from the hemolymph of nematode-infected G. mellonella larvae. Variability was observed in insect virulence in relation to the site origin of the nematodes. In vitro assays confirmed uptake of red fluorescence protein (RFP)-labeled Pseudomonas aeruginosa strain PA14 by nematodes. Bacteria were highly concentrated in the digestive tract of adult nematodes, some bacteria were observed in the digestive tract of juveniles with a more significant amount on their cuticle, and none on the cuticle of adults. RFP-labeled P. aeruginosa were not observed in hemolymph of G. mellonella larvae, indicating an apparent lack of bacterial transfer from juvenile nematodes to the insects despite larval mortality.
Host species was the primary factor affecting bacterial community profiles. Spiroplasma sp. and Serratia marcescens sequences were shared across ants, nematodes, and nematode-exposed G. mellonella larvae. Alternative to the idea of transferring bacteria from environment to host, we considered whether nematode-exposure might disorder or depauperate the endobiotic community of an insect host. While total bacterial diversity was not statistically lower in nematode-exposed G. mellonella larvae when compared to controls, 16 bacterial sequence variants were less abundant in nematode-exposed larvae, while three were increased, including Serratia, Pseudomonas, and Proteus. This study suggests that transfer of bacteria from nematodes to ants is feasible, although largely serendipitous, and may contribute to ant mortality in Maine. Hypothetically, the use of an engineered biological control, such as nematodes carrying specifically-seeded bacterial species, may be effective, especially if the pathogenic bacteria are naturally found in soil ecosystems and represent a low risk for biosafety control.
Poster Citation: Hotopp*, A., Silverbrand, S., Ishaq, S.L., Dumont, J., Michaud, A., MacRae, J., Stock, S.P., Groden, E. “Can a necromenic nematode serve as a biological Trojan horse for an invasive ant?” Ecological Society of America 2021. (virtual). Aug 2-6, 2021. (poster)
Ishaq, S.L., A. Hotopp2, S. Silverbrand2, J.E. Dumont, A. Michaud, J. MacRae, S. P. Stock, E. Groden. 2021. Assessment of pathogenic bacteria transfer from Pristionchus entomophagus (Nematoda: Diplogasteridae) to the invasive fire ant (Myrmica rubra) and its potential role in colony mortality in coastal Maine. iScience 24(6):102663. Article.
Talk #93066, “The effect of simulated warming ocean temperatures on the bacterial communities on the shells of healthy and epizootic shell diseased American Lobster (Homarus americanus)”
COS 87: Climate Change: Communities 1 Recorded talk available on demand.
The American lobster, Homarus americanus, is a vital species for the fishing industry along the North Atlantic coast of North America. However, populations in Southern New England have declined, most likely due to increasing ocean temperatures and prevalence of emerging disease. Our previous work suggested that temperature may not be the sole cause for epizootic shell disease (ESD). Here, we examined the shell bacterial communities and progression of ESD in non-shell diseased and diseased adult female lobsters under three simulated seasonal temperature cycles for a year.
Fifty-seven female lobsters were wild-caught from Maine’s management zones F and G, and were assessed for shell disease progression on a scale of 0 (no observable signs) to 3 (visible disease on >50% of the shell surface). ESD-negative lobsters (apparently healthy) and ESD-positive (diseased) lobsters were randomly dispersed into 3 systems, and within each system, healthy and diseased lobsters were placed into separate tanks. These systems were maintained at three temperature ranges comparable to the average seasonal ocean temperatures for Southern New England (SNE), Southern Maine (SME), and Northern Maine (NME) regions. Samples were collected at three timepoints, a baseline “summer” temperature where all tanks were the same temperature, a winter temperature four months later, and a summer temperature 10 months after that.
A total of 131 experimental samples, plus 10 controls, passed PCR amplification, amplicon quantification and purification, Illumina MiSeq ver. 4 sequencing, and quality-control filtering. Sequences were processed using the R software platform, using DADA2, phyloseq, vegan, and assorted other packages.
Results and conclusions
The bacterial richness on lobster shells at the baseline timepoint, when lobsters were wild-caught, was higher than the winter time point, 4 months later, or the summer time point, 10 months later, for the same lobsters after having been kept in tanks, regardless of their temperature or shell disease status. Similarly, the bacterial community membership (unweighted Jaccard similarity) was similar for all samples at baseline, but diverged for later time points.
Tank temperature significantly affected microbial community membership (unweighted Jaccard similarity), as well as the abundance of those community members (weighted Bray-Curtis dissimilarity).
Contrary to our expectations, ESD shell disease index did not progress over time or in warmer conditions, and we hypothesized that frequent tank water changes and shell moltings may have reduced the microbial load. Preliminary results indicate that shell stage and shell disease index were positively associated with increased bacterial richness on lobster shells.
Citation: Ishaq*, S.L., Lee, G., MacRae, J., Hamlin, H., Bouchard, D. “The effect of simulated warming ocean temperatures on the bacterial communities on the shells of healthy and epizootic shell diseased American Lobster (Homarus americanus).” Ecological Society of America 2021. (virtual). Aug 2-6, 2021. (accepted talk)
For some reason the ESA meeting site kept my Montana affiliation from 2017 for all 3 of my submissions.
SS 17: “Microbiomes and Social Equity” (19205)
Prerecorded content available on demand.
Live discussion: Thursday, August 5th, 2021, 9:30 AM – 10:30 AM Pacific Time
Microbiomes — environmental, human and other organismal symbionts — are increasingly seen as critical physiological, developmental and ecological mediators within and among living things, and between the latter and our abiotic environments. Therefore, it is no surprise that microbial communities may be altered, depleted or disrupted by social and economic determinants. Social inequality entails concrete alterations and differentiation of microbial communities among social groups, by way of such factors as nutritional access, environmental pollutants or green space availability, often to the detriment of human and ecosystem health. This special session will be organized as a panel discussion with break-out groups in order to provide participants the opportunity to discuss the ways in which social inequity interacts with microbiomes, and how we might intervene as scientists and communities to promote favorable microbiomes while advancing social equality. We hope to generate research questions and actionable items.
Panel speakers: Michael Friedman, Naupaka Zimmerman, Justin Stewart, Monica Trujillo, Sue Ishaq, Sierra Jech, Jennifer Bhatnagar, and Ariangela Kozik ESA meeting program: https://www.esa.org/longbeach/
Citation: The Microbes and Social Equity Working group, “Special Session 17: “Microbiomes and Social Equity” (19205).”, Ecological Society of America 2021. (virtual). Aug 5, 2021.
Recent Publication:
Ishaq, S.L., Parada Flores, F.J., Wolf, P.G., Bonilla, C.Y., Carney, M.A., Benezra, A., Wissel, E., Friedman, M., DeAngelis, K.M., Robinson, J.M., Fahimipour, A.K., Manus, M.B., Grieneisen, L., Dietz, L.G., Chauhan, A., Pathak, A., Kuthyar, S., Stewart, J.D., Dasari, M.R., Nonnamaker, E., Choudoir, M., Horve, P.F., Zimmerman, N.B., Kozik, A.J., Darling, K.W., Romero-Olivares, A.L., Hariharan, J., Farmer, N., Maki, K., Collier, J.L., O’Doherty, K., Letourneau, J., Kline, J., Moses, P.L., Morar, N. 2021. Introducing the Microbes and Social Equity Working Group: Considering the Microbial Components of Social, Environmental, and Health Justice. mSystems 6:4.
The Microbes and Social Equity Working Group is delighted to make its published debut, with this collaboratively-written perspective piece introducing ourselves and our goals. You can read about us here.
This piece also debuts the special series we are curating in partnership with the scientific journal mSystems; “Special Series: Social Equity as a Means of Resolving Disparities in Microbial Exposure“. Over the next few months to a year, we will be adding additional peer-reviewed, cutting edge research, review, concept, and perspective pieces from researchers around the globe on a myriad of topics which center around social inequity and microbial exposures.
Ishaq, S.L., Parada, F.J., Wolf, P.G., Bonilla, C.Y., Carney, M.A., Benezra, A., Wissel, E., Friedman, M., DeAngelis, K.M., Robinson, J.M., Fahimipour, A.K., Manus, M.B., Grieneisen, L., Dietz, L.G., Pathak, A., Chauhan, A., Kuthyar, S., Stewart, J.D., Dasari, M.R., Nonnamaker, E., Choudoir, M., Horve, P.F., Zimmerman, N.B., Kozik, A.J., Darling, K.W., Romero-Olivares, A.L., Hariharan, J., Farmer, N., Maki, K.A., Collier, J.L., O’Doherty, K., Letourneau, J., Kline, J., Moses, P.L., Morar, N. 2021. Introducing the Microbes and Social Equity Working Group: Considering the Microbial Components of Social, Environmental, and Health Justice. mSystems 6:4.
A few weeks ago, I sat down with Sheba A-J, one of the producers of the WeTalkScience podcast, to talk about one of my recent publications in the research journal iScience, at which Sheba is also an editor. Listen to find out how lobsters are like humans, how I got involved on a project working with ants and nematodes, and how you can help make science a more welcoming place.
Ishaq, S.L., A. Hotopp, S. Silverbrand, J.E. Dumont, A. Michaud, J. MacRae, S. P. Stock, E. Groden. 2021. Bacterial transfer from Pristionchus entomophagus nematodes to the invasive ant Myrmica rubra and the potential for colony mortality in coastal Maine. iScience 24(6):102663. Article.
Now that she has defended, Tindall will focus on revising the research thesis chapter which was not already published into a manuscript to submit for review at a scientific journal. After that, she is planning on pursuing her career in agricultural sustainability research and outreach.
RESPONSE OF SOIL BACTERIAL COMMUNITIES TO CROPPING SYSTEMS, TEMPORAL CHANGES, AND ENVIRONMENTAL CONDITIONS IN THE NORTHERN GREAT PLAINS
by
Laura Tindall Ouverson
Master of Science
Land Resources and Environmental Sciences
MONTANA STATE UNIVERSITY
Bozeman, Montana
July 12 2021
ABSTRACT
Soil bacterial communities are essential components of the soil ecosystem that support crop production and indicate a soil’s health. However, agriculture in semiarid drylands and their associated soil bacterial communities face increasingly warmer and drier conditions due to climate change. Two complementary studies were conducted to assess the response of soil bacterial communities to cropping systems, temporal changes, and soil temperature and moisture conditions in semiarid, dryland agricultural systems of the Northern Great Plains.
The first study focused on soil bacterial community response to crop phase (i.e., crop species) of a rotation in contrasting cropping systems (chemical inputs and no-till, USDA-certified organic tilled, and USDA-certified organic sheep grazed) over a growing season. Organic grazed management supported more diverse bacterial communities than chemical no-till, though diversity in all systems decreased over the growing season. Organic grazed bacterial communities were distinct from those in the organic tilled and chemical no-till systems. An interaction between cropping system and crop phase affected community dissimilarity, indicating that overarching management systems and environmental conditions are influential on soil bacterial communities.
The second study evaluated soil bacterial communities in a winter wheat-cover crop or fallow rotation. Observations were conducted in the summer fallow and two cover crop mixtures differing by species composition and phenologies, terminated by three different methods (chemical, grazing, or haying), and subjected to either induced warmer/drier or ambient soil conditions. Only the presence and composition of cover crops affected bacterial community dissimilarity. Bacterial communities responded to an interaction between the presence and composition of cover crops and environmental conditions, but not termination. Additionally, soil bacterial communities from mid-season cover crops were distinct from early season and fallow. No treatments affected bacterial communities in 2019, which could be attributed to historic rainfall. Cover crop mixtures including species tolerant to warmer and drier conditions can foster diverse soil bacterial communities compared to fallow soils.
Overall, these studies increased our understanding of how soil bacterial communities respond to soil health building practices in the Northern Great Plains. Cropping systems can foster unique soil bacterial communities, but these effects may be moderated by environmental and temporal conditions.
A collaborative pilot project was funded by the Maine Food and Agriculture Center (MFAC) to investigate Vibrio bacteria in scallop hatcheries in Maine! This will support some ongoing work by a collaborative research team at UMaine and the Downeast Institute, as we develop a long-term, larger-scale project investigating scallop health and survival in hatcheries, something which will be critical to supporting sustainable and economically viable aquaculture productions.
“Investigating microbial biofilms in Maine hatchery production of sea scallop, Placopecten magellanicus.”
Principal Investigator: Sue Ishaq
Co-Investigators:
Dr. Tim Bowden, Associate Professor of Aquaculture, University of Maine
Dr. Jennifer Perry, Assistant Professor of Food Microbiology, University of Maine
Dr. Brian Beal, Professor of Marine Ecology, University of Maine at Machias; and Research Director/Professor, Downeast Institute
Dr. Erin Grey, Assistant Professor of Aquatic Genetics, University of Maine
Project Summary: Atlantic deep-sea scallops, Placopecten magellanicus, are an economically important species, generating up to $9 million in Maine alone. Despite their potential to the aquaculture industry, hatchery-based sea scallop production cannot rely on the generation of larvae to produce animals for harvest. In hatcheries, the last two weeks of the larval maturation phase is plagued by massive animal death, going from 60 million scallop larvae down to a handful of individuals in a span of 48 hours. This forces farmed scallop productions to rely on collection of wild scallop spat (juveniles), but wild population crashes, habitat quality, harvesting intensity, and warmer water temperatures threaten the sustainability and economic viability of this industry. The reasons for sea scallop larvae death remain unknown, but other cultured scallop species are known to suffer animal loss from bacterial infections, including from several bacterial species of Vibrio and Aeromonas. At the Downeast Institute in Beals, Maine, biofilms appear on tank surfaces within 24 hours. Routine screening for the presence of Vibrio sp. in tanks at DEI reveals no obvious signs of colonies in scallop tanks. Preliminary culturing and genetic identification from these biofilms suggests a species of Pseudoalteromonas, known biofilm formers which outcompete or inhibit other microorganisms. Our goal is to investigate the dynamics of tank surface biofilms in bivalve aquaculture facilities. Our long-term goals are to understandmicrobial community assembly and animal health during scallop hatchery production, and to standardize management practices to enhance the success of cultured scallop production.
Experimental design schematic for this project. Our objectives are to 1) Identify the microbial community members involved in tank biofilms, and if it is a repeated or novel community assembly, and 2) Test for biofilm antagonism in vitro, using competing microorganisms, chemical treatments, and environmental conditions.
I’m delighted to announce that a paper was published on the effect of a dietary additive on the rumen and fecal bacterial communities in dairy cattle, in the journal Animal: The International Journal of Animal Biosciences!
A lot of factors can be manipulated to help get the most out of one’s diet, including the source and processing method of the ingredients – in most cases in livestock feed: plants. Growing plants for animal feed can be expensive, and often nutrients in plants become more available to the animal after the plant has been processed/broken down in some way. This sometimes allows for food byproducts to be reused for animal feed, and one common example is used brewers’ grains. Once the grains have been fermented to produce alcohol, the simple sugars have been used up but a lot of the complex sugar carbohydrates – in other words: fiber – are left over. Ruminants don’t need simple sugars, but they do need a lot of fiber, and brewers’ grains have been investigated for their usefulness for animal nutrition because they are a cheap, readily-available, and common source of fiber, as well as protein.
The original experiment for this work took place several years ago, and involved an animal feeding trial which added reduced-fat distillers’ grains with solubles into dairy cattle feed. The research team found no negatives effect on milk production or animal health, and that work was previously published. To add to that project, the original research team wanted to know if the diet would drastically change the bacterial community living in the rumen, which would have implications for feed digestion and animal health.
A collaborator of mine donated the cow microbial community DNA data to my AVS 590 special topics in DNA Sequencing Data Analysis course in spring 2020 (now formally registered as AVS 454/554). I worked with UMaine graduate students Adwoa Dankwa and Usha Humagain over the semester to train them in coding and develop the manuscript. The diet only had minimal effects on the bacterial community profiles, which in this case is a good finding – we want to be able to feed a cheap, nutritional source like distillers’ grains without harming the cow or its microbes.
Reduced-fat dried distillers’ grains with solubles (RF-DDGS) is a co-product of ethanol production and contains less fat than traditional distillers’ grains. The fat in corn is ~ 91% unsaturated, and it is toxic to rumen microorganisms so it could influence the composition of the rumen microbiome. It has been demonstrated that RF-DDGS is a suitable ration ingredient to support the high-producing dairy cow, and this feedstuff is a promising alternative protein source for lactating dairy cows. The current study aims to better understand the effect of RF-DDGS on the rumen and fecal bacterial composition in lactating dairy cows. Thirty-six multiparous (2 or 3), mid-lactation Holstein cows (BW = 680 ± 11 kg; 106 ± 27 DIM) were randomly assigned to two groups which were fed a control diet made up of corn, corn silage, and alfalfa hay supplemented with expeller soybean meal or with added RF-DDGS (20% of the dry matter (DM)) containing approximately 6.0% fat. Whole rumen contents (rumen fluid and digesta; esophageal tubing method) and feces (free catch method) were collected on day 35 of the experimental period, after the 14-d acclimation period. Rumen contents and feces from each cow were used for DNA extraction. The bacterial community composition in rumen and fecal samples was assessed via the 16S rRNA gene by using the Illumina MiSeq sequencing platform. Bacteroidetes, Actinobacteria, and Firmicutes were the most abundant phyla in rumen contents. The fecal microbiota was dominated by the phyla Firmicutes and Bacteroidetes, as well as Actinobacteria and Chloroflexi. RF-DGGS increased bacterial richness, evenness, and Shannon diversity in both rumen and fecal samples and was associated with several taxa that had different abundance in treatment versus control comparisons. The RF-DGGS, however, did not significantly alter the bacterial community in the rumen or feces. In general, these findings demonstrated that dietary inclusion of RF-DDGS did not impose any serious short-term (within 30 days) health or production consequences, as would be expected. With this study, we present further evidence that inclusion of 20% (DM basis) RF-DDGS in the diet of lactating dairy cows can be done without consequence on the microbiome of the rumen.
Implications
Reduced-fat dried distillers’ grains with solubles is a quality, economical, and readily available protein source demonstrated to support the protein needs of high-producing dairy cows. In this study, the rumen and fecal bacterial communities of lactating dairy cows were not significantly influenced by 20% (dry matter basis) reduced-fat dried distillers’ grains with solubles and did not impose serious short-term (within 30 days) health or production consequences. This diet could potentially be introduced into Total Mixed Ration feeding of dairy cattle given the fact that it is readily available and relatively economical.
Last week, the Microbes and Social Equity working group hosted its first ever symposium! We hosted 15 talks over 5 days, with each session melding presentations and active discussion groups.
In total, the symposium had 254 participants (467 registrants) from 22 countries, and including researchers from various fields and career levels, as well as members of the Maine State Legislation, and members of the general public. The breakout rooms resulted in 16 draft documents collaboratively written by meeting ideas, which highlight issues/barriers to social equity in research and practice, resources and policy ideas to resolve inequity, research questions yet to be answered, and ideas for curricula development and integrating research and policy into education.
The Ishaq Lab 