Microbiology Commons^™

Systemic Infection Of Beauveria Bassiana In A Stranded Endangered Green Turtle Chelonia Mydas: A Case Report, Ming-An Tsai, I-Chun Chen, Tsung-Hsien Li

The Thai Journal of Veterinary Medicine

The green turtle (Chelonia mydas) is the most frequently encountered marine turtle species in Taiwan. This study describes the postmortem findings of a juvenile green turtle with injuries to the right foreflipper that was rescued off the Taiwan coast and died after 3 months in rehabilitation. Necropsy revealed large, yellow, multifocal caseous lesions involving the right foreflipper, spleen, liver, kidneys, and lungs. Fungal infection of Beauveria bassiana was confirmed by culture, morphological and molecular characterization, phylogenetic analysis, and histopathological examination. This report provides evidence that B. bassiana is associated with a systemic fungal infection which can be fatal …

In Vivo Expression Profiling Of Listeria Monocytogenes Internalins (Inlf, Inlp, Inlj) And Their Corresponding Host Receptors (Vim, Afdn, Muc2) Using A Rabbit Ligated Intestinal Loop Model, Nawar Al-Janabi, Nadhim Mushtaq Hashim Al-Bderee, Zahraa M. Madania, Mohanad Jawad Kadhim

Karbala International Journal of Modern Science

Listeria monocytogenes is a Gram-positive pathogen that causes severe infections, particularly in immunocompromised individuals. Internalin genes are important virulence factors that facilitate the bacterium's invasion of host cells. This research aimed to quantify in vivo expression of selected internalin genes (inlF, inlP, and inlJ) and their corresponding host receptors (VIM, AFDN, and MUC2) during L. monocytogenes infection. To achieve this aim, a rabbit ligated intestinal loop model was constructed comprising two intestinal loops. The first loop was injected with 1 mL of L. monocytogenes (1 × 10⁷ CFU/mL), while the second loop was injected with 1 mL of PBS as …

Pharky, Phedro, Phractured, And Stagephright: Complete Genome Sequences Of Four Ek2 Cluster Microbacterium Phages, Susan M. R. Gurney, Medha Gupta, Deeksha Reddy, Gloria Zacharias, Aleda S. Jomy, Carly J. Smith, Matthew T. Mcdonald, Brett M. Condon

Student Papers, Posters & Projects

We report the complete genome sequence of four Microbacterium phages, Pharky, Phedro, Phractured, and StagePhright, isolated using the bacterial host Microbacterium foliorum from soil samples collected in Philadelphia. All four phages are genetically very similar and contain a gene of unknown function, which is uncommon in the EK2 cluster.

Homocysteine Thiolactone From Translation Proofreading Is An Endogenous Ligand For Cell-Cell Signaling By The Receptor Sdia, Lorenzo Eugenio Leiva, Roberto A. Zúñiga, Gregory J. Phillips, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Several widespread mechanisms enable cellular communication and coordinate the behavior of bacterial populations. The modules responsible for cellular communication are often found in matching pairs: an enzyme that synthesizes a signal molecule and a specific receptor that decodes it. A notable exception is Escherichia coli SdiA, a homolog of known N-acyl-homoserine lactone (AHL) receptors, for which no corresponding AHL synthase exists. SdiA is an orphan receptor that enables cross-talk by sensing AHLs from other bacterial species. In this work, we investigated whether homocysteine thiolactone (HTL), an AHL-like molecule arising from a proofreading reaction of methionyl tRNA synthetase (MetRS) to correct …

Understanding The Effects Of Simulated Microgravity On Staphylococcus Epidermidis And Escherichia Coli In Co-Culture, Emma Costa, Mitchell K. Villafania, Makaila Olson, Kareigh N. Gammon, Hugo Castillo

Beyond: Undergraduate Research Journal

With the popularity of space travel increasing, it is important to understand the effects of microgravity on microbial communities as alterations on bacterial interactions can occur. Staphylococcus epidermidis and Escherichia coli are bacteria that are commonly found within human microbiomes. S. epidermidis is a cocci-shaped gram-positive bacterium that is part of the human skin microbiome. However, it can gather on sites of open skin and enter the body leading to an infection. E. coli is a rod-shaped gram-negative bacterium that can be found in the human gut microbiome. The pathogenic strains of E. coli have the potential to cause harmful …

Effectiveness Of Organic Amendments In Enriching Nitrogen In Compost Produced From Organic Fractions Of Market Waste Generated In Dar Es Salaam, Tanzania, Amani Bilula, Ally Mahadhy, Anthony Manoni Mshandete, Amelia Kivaisi

Tanzania Journal of Science

Low nitrogen (N) content remains a key limitation of compost derived from urban organic waste. This study evaluated the effectiveness of selected plant-based organic amendments in enhancing nitrogen content and improving compost quality. Four plant- based organic amendments, Leucaena leucocephala (BN01), Commelina benghalensis (BN02), Morus alba (BN03), and Helianthus annuus (sunflower) cake (BN04), were incorporated into market waste compost at ratios of 1:0.06:0.04, 1:0.06:0.25, and 1:0.06:0.5 (organic waste: sawdust: amendment). Composting was conducted using a 4 × 3 factorial design with three replicates per treatment (n = 36). Temperature, moisture, and pH were monitored throughout the composting period. Total nitrogen, …

Birds Of A Tether Flock Together: Examining Centromere Tethering And Chromosome Segregation In Caulobacter Crescentus, Jake Dwyer, Simon Kruczak, Rodrigo Arana-Garrido, Paola Mera

MICRO-CCS student projects

Introduction:

Chromosome segregation is essential for all domains of life. Caulobacter crescentus is a key model for studying this process. It divides asymmetrically into two morphologically distinct cells. Proteins can be seen directly with fluorescent tags.

Research done on Caulobacter can apply to many different bacteria. The ParABS system is integral to chromosome segregation in Caulobacter.

ParS – DNA sequence on the chromosome

ParB – CTP-binding protein that specifically recognizes parS

ParA – ATP-binding protein that non-specifically binds DNA and provides the force for segregation.

PopZ – Polar tethering protein via interactions with ParB.

TipN - Polar protein that …

Has Plant Domestication Compromised Plant Defensive Chemistry? Aphid Induced Stress In Tomatoes, Nhi Do, Satinderpal Kaur, Minxing Zhu, Esther N. Ngumbi

MICRO-CCS student projects

Tomato plants have natural defensive mechanisms.

Direct: Phenolics are secondary metabolites that can protect the plant by intoxicating the herbivores and/or producing strong repulsive odors.

Indirect: VOCs, Volatile Organic Chemicals, are gas phase signals that attract the predators of the attacking herbivore to the plant.

Domestication of plants may chemically alter these defenses by prioritizing fruit production over defensive traits.

We hypothesize that wild/ancient tomato plants would have a greater quantity of volatiles and increased concentration of leaf total phenolics compared to cultivated tomatoes during aphid herbivory.

How Does High-Oil Sorghum Change Potential Extracellular Enzyme Activity Across Soil Depth Profiles Under Drought Conditions?, Krystal Monique Role, Rounak Patra, Wendy Yang

MICRO-CCS student projects

Transgenic oil sorghum reallocates photosynthate-carbon (C) into vegetative lipids, accumulating nonstructural lipids in both shoot and root tissues. Altered plant C allocation and root lipid accumulation may shift root exudate chemistry, belowground C inputs, and microbial nutrient demand throughout the soil profile. While aboveground productivity in high-oil sorghum is well-characterized, its belowground impacts on soil microbial enzyme activity and exchangeable cation dynamics, especially across soil horizons under drought stress remain unknown.

Project objective was to find out how transgenic high oil sorghum (Tx-HO1) influences CNP acquiring extracellular enzyme activities and soil exchangeable cation dynamics across soil horizons under drought and …

Investigation Of Biological Denitrification Inhibition By Specific Anthocyanins, Kristin Palazzo, Holly Anderson, Aislinn Geedey, Angela Kent

MICRO-CCS student projects

Nitrogen fertilizers are applied to corn fields to support high crop yields, but some nitrogen is lost through microbial denitrification, producing nitrous oxide (N2O), a potent greenhouse gas. Some plants produce certain flavonoids that can suppress microbial denitrification, a trait known as biological denitrification inhibition (BDI). Maize produces flavonoids in the form of anthocyanins, including cyanidin-3-glucoside (C3G), the major anthocyanin produced by maize.

The goals of this project were to determine whether C3G:

is produced in maize roots

inhibits microbial denitrification

Recovering Plasmid-Id Barcoded Strains Of Sinorhizobium Meliloti From A Native Soil Microbiome, Kenny Sacks, Hannah Murray, Katy Heath

MICRO-CCS student projects

Introduction

Legume-Rhizobia Mutualism: Nitrogen is an essential nutrient for plant growth. Plants can’t produce nitrogenous compounds. Rhizobia fix atmospheric nitrogen gas into bioavailable forms. Rhizobia form a nutrient exchange mutualism with leguminous plants.

Project description

Can our bacteria persist within the rhizosphere and into the nodule when faced with native microbial competitors? The Medicago-Sinorhizobium mutualism is used as a model system. Survival of strains post competition is difficult to measure due to identical 16S rRNA sequences and similar marker genes. Plasmid-ID barcoding sequences may provide a way of testing strains against a community.

Soil Microbiome Effect On Seedling Diseases And High Throughput Isolate Identification, Annalaysia Smith, Mara Krone, Santiago Mideros

MICRO-CCS student projects

The soil microbiome has a substantial effect on disease suppression. Organic farming is a practice used to create a more diverse microbiome which can create disease suppression. Different agricultural practices such as fertilization and rotation system are known to affect the microbiome (Schlatter et al 2017). Therefore, it is important to study the effects of different microbiomes on disease suppression. Furthermore, methods are necessary for quantifying the effect of disease suppression on specific pathogen populations. To do this, it is important to properly identify the pathogens.

Objectives:

1. Test if different nitrogen treatments cause variations in organic soils disease suppression. …

Effects Of Varying Ph Levels On Prophenoloxidase Activity And Hemocyte Recruitment In Daphnia Dentifera, Yusra Siddiqi, Carla Caceres

MICRO-CCS student projects

Anthropogenic activities and natural processes are responsible for changing the pH of freshwaters which can impact aquatic life. D. dentifera is a keystone species found in midwestern lakes that is susceptible to a parasitic yeast called Australozyma monospora. A. monospora spores puncture the Daphnia gut into the hemolymph and begin using the host’s resources. Invertebrate immunity is under researched.

Research objective: How will different pH impact prophenoloxidase (proPO) activity and hemocyte recruitment in Daphnia dentifera?

Screening A Random Hile Mutant Library To Characterize Hild Regulation In Salmonella, Danista Kannah, Gracious Donkor, James M. Slauch

MICRO-CCS student projects

Salmonella is a leading cause of gastrointestinal diseases globally. It utilizes a type three secretion system (T3SS) encoded on Salmonella Pathogenicity Island 1 (SPI1) to invade host intestinal epithelial cells during infection.

HilE directly regulates HilD via a direct protein-protein interaction. The Slauch lab identified two HilD variants, A141V and A141T, which are blind to HilE. These variants activate hilA expression even in the presence of HilE, indicating that the binding of HilE to these mutants is compromised.

Hypothesis: Performing random mutagenesis of hilE could lead to changes at the protein level which could compensate for the loss of interaction …

Fungal Diversity In Lespedeza Cuneata Roots, Gwendolyn Happ, Sophia Mcdade, Anthony Yannarell

MICRO-CCS student projects

Background

• Plants form a relationship with fungi that can be beneficial or harmful
• Fungi may grow on the plant surface, within plant tissues, or around roots
• Plants release compounds that invite fungi to their roots and chemicals  that can diminish unwanted fungi

Why Lespedeza cuneata? 

• Invasive that competes with native plants and damages biodiversity within plant and animal communities
• Alters soil microbiome
• Expansive seed bank and deep root system
• Understanding its microbiome can help in understanding invasive species success and ecology

Efficacy And Evolutionary Dynamics Of 222 Nm Far-Uvc Against Vibrio Cholerae, Kadicha Madakimova, Angus Wu, Nkrumah Grant

MICRO-CCS student projects

The Far-UVC light at 222 nm wavelength (UV222) is one of the emerging methods of disinfection of bacteria in public spaces such as hospitals and labs.

• Does not penetrate human skin and does not cause harm to eyes making it a safer alternative to conventional UV systems.

• Primarily targets proteins preventing regrowth and repair pathways.

However, the potential for bacterial adaptation following sublethal UV222 exposure remains largely unknown.

Central question: How does QS transcriptional state influence the efficacy and resistance profile of V. cholerae to UV222 nm irradiation?

Hypothesis: Qurom-sensing transcriptional state determines V. cholerae susceptibility to UV222 nm UV …

A Tale Of Two Symbionts: Comparative Cellular Localization Of Two Manipulative Rickettsiella Strains In A Spider, Kaitlyn Costanza, Thea Bliss, Matthew Doremus

MICRO-CCS student projects

Many arthropods harbor maternally transmitted endosymbionts that manipulate host reproduction to increase their transmission. One such manipulation is cytoplasmic incompatibility (CI), in which embryos produced by infected males and uninfected females fail to develop.

Rickettsiella has recently been discovered to cause CI in Mermessus fradeorum. Two geographically distinct Rickettsiella strains infect this spider: R1 causes strong CI, whereas R2 causes weaker CI.

Hypothesis: H1: Both Rickettsiella strains will localize within or near developing sperm cells in the testes. H2: The stronger R1 strain will exhibit more consistent localization within infected adult reproductive tissues than the weaker R2 strain.

The Deep Darkness Microbiome: Functional And Taxonomic Diversity In An Oligotrophic Temperate Cave, Philips O. Akinwole, Nina G. Shaffer '25, Emma E.C. Jacobs '25, Zoe Green '27, Thi Doan '27, Crimson Hickman '28, Kaija M. Carr '25, Kenneth L. Brown

Biology Faculty publications

Many subterranean ecosystems are chronically energy limited, yet the mechanisms governing microbial community assembly and metabolic function under extreme carbon scarcity remain poorly resolved. We combined 16S rRNA gene sequencing with community-level physiological profiling (CLPP) to examine how physicochemical gradients regulate microbial diversity and carbon-use strategies across a surface-subsurface transition into the Deep Darkness zone of Indiana Caverns. Progressive isolation from surface inputs resulted in sharp declines in microbial biomass, total organic carbon, and nitrogen, accompanied by increased water content and C:N ratios, indicating strong attenuation of allochthonous organic matter and intensified resource filtering. Microbial communities spanned 42 bacterial phyla, …

Endophytic Actinobacteria: Deciphering Therapeutic And Industrial Potential, And Prospects Of Genome Mining In Novel Products Discovery, Yusra Waheed, Rabia Shahdin, Imran Sajid

Journal of Bioresource Management

Endophytic actinobacteria are a diverse group of Gram-positive bacteria with high G+C content, which inhabit plants’ internal tissues, and represent a significant yet underexplored reservoir of bioactive secondary metabolites. In host plants, a remarkable repertoire of metabolites, including broad-spectrum antibiotics, anticancer, antiviral, antifungal, antioxidant, and immunomodulatory compounds, is synthesized by these microbial allies, carrying significant medicinal and agricultural potential. These endophytes, in contrast to their soil relatives, have developed unique biosynthetic gene clusters (BGCs) strongly influenced by plant-associated factors, leading to the production of structurally novel metabolites. In recent years, the advances in genome mining, metagenomics, and metabolomics have accelerated …

Mobile Genetic Elements Shape Microbial Diversity And Functions In Thawing Permafrost Soils, Jiarong Guo, Samuel T. N. Aroney, Guillermo Domínguez-Huerta, Derek Smith, Dean Vik, Carlos Owusu-Ansah, Akbar Adjie Pratama, Sergei Solonenko, Funing Tian, Cristina Howard-Varona, Zhi-Ping Zhong, Aminata Fofana, Garrett J. Smith, Suzanne B. Hodgkins, Dylan Cronin, Isogenie Field Teams 2010–2017, 2019, Emerge Coordinators, Ben J. Woodcroft, Gene W. Tyson, Virginia I. Rich, Matthew B. Sullivan, Simon Roux, Sarah C. Bagby, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Ecosystems are shaped by communities of microorganisms whose niches and impacts depend on functional profiles influenced by gene gains and losses. Culture-based experiments demonstrate that mobile genetic elements (MGEs) can mediate gene flux, but quantitative understanding of these dynamics in natural systems remains limited. Here we develop and apply a systematic, meta-omic framework to investigate MGEs in a complex natural system using an 8-year soil time series collected at Stordalen Mire, in Sweden’s thawing permafrost margin. In this climate-critical peatland, we identify ~2.1 million MGE recombinases across 89 microbial phyla and assess ecological distributions, affected functions, past mobility and current …