Microbiology Commons^™

Using Molecular Diagnostics To Develop Therapeutic Strategies For Carbapenem-Resistant Gram-Negative Infections, Fred C. Tenover

Biology Faculty Publications

Infections caused by multidrug-resistant Gram-negative organisms have become a global threat. Such infections can be very difficult to treat, especially when they are caused by carbapenemase-producing organisms (CPO). Since infections caused by CPO tend to have worse outcomes than non-CPO infections, it is important to identify the type of carbapenemase present in the isolate or at least the Ambler Class (i.e., A, B, or D), to optimize therapy. Many of the newer beta-lactam/beta-lactamase inhibitor combinations are not active against organisms carrying Class B metallo-enzymes, so differentiating organisms with Class A or D carbapenemases from those with Class B enzymes rapidly …

Phenotypic/Genotypic Profile Of Oxa-10-Like-Harboring, Carbapenem-Resistant Pseudomonas Aeruginosa: Using Validated Pharmacokinetic/Pharmacodynamic In Vivo Models To Further Evaluate Enzyme Functionality And Clinical Implications, Fred C. Tenover, Christian M. Gill, Adrian Brink, Chun Yat Chu, Jennifer Coetzee, George Dimopoulos, Clinton Moodley, Christoffel Johannes Opperman, Spyros Pournaras, Isabella A. Tickler, Hafsah Deepa Tootla, Sophia Vourli, David P. Nicolau

Biology Faculty Publications

In vitro MICs and in vivo pharmacodynamics of ceftazidime and cefepime human-simulated regimens (HSR) against modified carbapenem inactivation method (mCIM)-positive Pseudomonas aeruginosa isolates harboring different OXA-10-like subtypes were described. The murine thigh model assessed ceftazidime (2 g every 8 h [q8h] HSR) and cefepime (2 g and 1 g q8h HSR). Phenotypes were similar despite possessing OXA-10-like subtypes with differing spectra. Ceftazidime produced ≥1-log10 killing in all isolates. Cefepime activity was dose dependent and MIC driven. This approach may be useful in assessing the implications of β-lactamase variants.

Insights Into Halophilic Microbial Adaptation: Analysis Of Integrons And Associated Genomic Structures And Characterization Of A Nitrilase In Hypersaline Environments, Sarah Sonbol

Theses and Dissertations

Hypersaline environments are extreme habitats that can be exploited as biotechnological resources. Here, we characterized a nitrilase (NitraS-ATII) isolated from Atlantis II Deep brine pool. It showed higher thermal stability and heavy metal tolerance compared to a closely related nitrilase.

We also studied integrons in halophiles and hypersaline environments. Integrons are genetic platforms in which an integron integrase (IntI) mediates the excision and integration of gene cassettes at specific recombination sites. In order to search for integrons in halophiles and hypersaline metagenomes, we used a PCR-based approach, in addition to different bioinformatics tools, mainly IntegronFinder.

We found that integrons and …

Unbiased Automated Quantitation Of Ros Signals In Live Retinal Neurons Of Drosophila Using Fiji/Imagej, Prajakta Deshpande, Neha Gogia, Anuradha Venkatakrishnan Chimata, Amit Singh

Biology Faculty Publications

Numerous imaging modules are utilized to study changes that occur during cellular processes. Besides qualitative (immunohistochemical) or semiquantitative (Western blot) approaches, direct quantitation method(s) for detecting and analyzing signal intensities for disease(s) biomarkers are lacking. Thus, there is a need to develop method(s) to quantitate specific signals and eliminate noise during live tissue imaging. An increase in reactive oxygen species (ROS) such as superoxide (O2•-) radicals results in oxidative damage of biomolecules, which leads to oxidative stress. This can be detected by dihydroethidium staining in live tissue(s), which does not rely on fixation and helps prevent stress on tissues. However, …

Overcoming Obstacles In Protein Expression In The Yeast Pichia Pastoris: Interviews Of Leaders In The Pichia Field, Zoe Ingram, Abha Patkar, Dahoon Oh, Kevin K. Zhang, Christina Chung, Joan Lin-Cereghino, Geoff P. Lin-Cereghino

Pacific Journal of Health

The yeast Pichia pastoris (also known as Komagataella pastoris) has been used for over 30 years to produce thousands of valuable, heterologous proteins, such as insulin to treat diabetes and antibodies to prevent migraine headaches. Despite its success, there are some common, stubborn problems encountered by research scientists when they try to use the yeast to produce their recombinant proteins. In order to provide those working in this field with strategies to overcome these common obstacles, nine experts in P. pastoris protein expression field were interviewed to create a written review and video (https://www.youtube.com/watch?v=FyC9xXVLyD0). This review describes …

Telomeric And Sub-Telomeric Structure And Implications In Fungal Opportunistic Pathogens, Raffaella Diotti, Michelle Esposito, Chang Hui Shen

Publications and Research

Telomeres are long non-coding regions found at the ends of eukaryotic linear chromosomes. Although they have traditionally been associated with the protection of linear DNA ends to avoid gene losses during each round of DNA replication, recent studies have demonstrated that the role of these sequences and their adjacent regions go beyond just protecting chromosomal ends. Regions nearby to telomeric sequences have now been identified as having increased variability in the form of duplications and rearrangements that result in new functional abilities and biodiversity. Furthermore, unique fungal telomeric and chromatin structures have now extended clinical capabilities and understanding of pathogenicity …

Implementing Crispr-Cas9 Gene Editing System In Microbotryum., Stevana Reese Schauer

College of Arts & Sciences Senior Theses

Microbotryum dianthorum is a species of smut fungus which causes infection in plants in the Dianthus genus. The infection process is aided by small-secreted proteins known as effectors. Effectors may aid in the infection process because they are secreted by the fungus and can enter plant tissue, possibly to facilitate infection and/or manipulate the host. Thus, it is of interest to investigate the genes for these effectors to determine their role in the infection process. One method to study genes is through gene disruption, via the CRISPR/Cas9 gene editing system, but this has not yet been implemented in Microbotryum dianthorum …

Identification Of Proteins That Contribute To Yeast Heat Stress By Lysine Acetylation, Weijia Shi

Biological Sciences Undergraduate Honors Theses

Evidence is emerging that protein lysine acetylation may be a novel type of post-translational modification (PTM) contributing to the mechanisms of yeast heat stress responses. Proteomics studies including ours have identified over 1,000 acetylated proteins in the yeast proteomes that are composed of about 6,000 proteins. Our lab recently identified 596 proteins that underwent acetylation changes during heat shock by mass spectrometry. However, the role of lysine acetylation on specific residues of specific proteins in yeast thermotolerance remains largely unknown. This study selected 43 proteins from our lab’s previous work and examined their possible contributions to yeast heat stress responses. …

A Peek Inside The Machines Of Bacterial Nucleotide Excision Repair, Thanyalak Kraithong, Silas Hartley, David Jeruzalmi, Danaya Pakotiprapha

Publications and Research

Double stranded DNA (dsDNA), the repository of genetic information in bacteria, archaea and eukaryotes, exhibits a surprising instability in the intracellular environment; this fragility is exacerbated by exogenous agents, such as ultraviolet radiation. To protect themselves against the severe consequences of DNA damage, cells have evolved at least six distinct DNA repair pathways. Here, we review recent key findings of studies aimed at understanding one of these pathways: bacterial nucleotide excision repair (NER). This pathway operates in two modes: a global genome repair (GGR) pathway and a pathway that closely interfaces with transcription by RNA polymerase called transcription-coupled repair (TCR). …

Utilizing Plastic-Degrading Microbes For Plastic Degradation, Brandon Garcia

Global Sustainable Development Projects

Our oceans are full of pollution and a large portion of those are plastics. They resist degradation from the elements and have long half-lives. About 300 million metric tons of plastic are dumped into our oceans every year. Many of these include polyethylene (PE), polypropylene (PP), polystyrene (PS), etc. Much of this is not recycled and so there is a massive accumulation of it present in our oceans. Microbes tend to form biofilms on these plastics and break them down. However, the relationship between plastics and the diversity of biofilm communities are being understood as well as how we can …

Characterizing The Physiology And Genetics Of Contact Dependent Growth Inhibiton Systems In Burkholderia Species, Alice Elizabeth Oates

Theses and Dissertations--Microbiology, Immunology, and Molecular Genetics

Contact-dependent growth inhibition (CDI) systems mediate interbacterial competition. The genes encoding these systems are widespread among Gram-negative bacteria, including Burkholderia pathogens. CDI systems of Burkholderia species are composed of two-partner secretion pathway proteins and function to deliver the toxic C-terminus of a polymorphic surface-exposed exoprotein BcpA (Burkholderia CDI protein A) to the cytoplasm of neighboring recipient bacteria upon cell-cell contact. Specific outer and inner membrane proteins facilitate BcpA translocation both out of the donor bacterium and into the recipient cell cytoplasm. Most Burkholderia species-specific CDI translocation factors in recipient cells are unknown. BcpA intoxication functions as a mechanism by …

Circadian Rhythmicity And Melatonin Sensitivity In The Human Gut Commensal Bacterium Klebsiella Aerogenes, Kinga Graniczkowska

Theses and Dissertations--Biology

While the expression of circadian rhythms is nearly universal among multicellular eukaryotic organisms, demonstration of this phenomenon in prokaryotes has been largely restricted to photosynthetic cyanobacteria until very recently. Further, growing interest in gastrointestinal microbiomes has revealed a complex temporal relationship between the gastrointestinal clock and the bacterial microbiome within. At least one member of the gut microbiome, Klebsiella (née Enterobacter) aerogenes, responds to the indoleamine hormone melatonin, secreted by the gastrointestinal system itself. Further research revealed that K. aerogenes also expresses a circadian rhythm in motility and gene expression that is temperature compensated. Although rhythmicity is unaltered …

Molecular And Genetic Studies On A Sipd/Ipad-Related Virulence Spike Protein From Immune-Suppressive Particles Of A Drosophila Parasitoid, Carlo Miguel A. Sevilla

Dissertations and Theses

Parasitoid wasps are effective biological control agents that have evolved intricate host immune suppression strategies to overcome host immune defenses. The most important anti-parasite defense mechanism is encapsulation, where the host’s blood cells surround the wasp egg. In the Drosophila/Leptopilina host-parasitoid system, extracellular vesicles (EVs) are oviposited along with the wasp egg. The EVs possess spikes and contain hundreds of proteins, some of which enable wasp eggs to escape encapsulation by changing the morphology and function of hemocytes, or killing them. Previous studies have identified an abundant surface/spike protein (SSp40) from Leptopilina heterotoma EVs. While p40, a predicted …

Multistrain Hiv-1 Elimination: A Crispr-Cas9 And Theranostics-Based Approach, Jonathan Herskovitz

Theses & Dissertations

A critical barrier to achieving a functional cure for infection by human immunodeficiency virus type one (HIV-1) rests in the presence of latent proviral DNA integrated in the nuclei of host CD4+ T cells and mononuclear phagocytes. Accordingly, HIV-1-infected patients must adhere to lifelong regimens of antiretroviral therapy (ART) to prevent viral rebound, CD4+ T cell decline, and progression to acquired immunodeficiency syndrome (AIDS). Gene editing using clustered regularly interspersed short palindromic repeat (CRISPR)-Cas9 technology stands as one means to inactivate integrated proviral DNA. We devised a mosaic gRNA CRISPR-Cas9 system- TatDE- that targets viral transcriptional regulator genes tat / …

Innate Pathogenic Traits In Oral Yeasts, Ayat Ibrahiem Esmaeel Al-Laaeiby, Adnan A. Al-Mousawi, Inaam M.N. Alrubayae, Abdullah Al-Saadoon, Maysoon Almayahi

Karbala International Journal of Modern Science

The normal flora community plays a significant role in both healthy and patient individual’s bodies. It has improved its ability to change from beneficial to opportunistic organisms causing crucial infections in immunocompromised patients. This study was conducted to identify the community of yeast species, and to investigate potential virulence factors. Saliva samples were collected from healthy individuals, yeast species were isolated and identified using both traditional and advance molecular genetics technique. The results revealed that Candida albicans was the dominant isolate, while Meyerozyma caribbica was the least. The phylogenetic tree was constructed for 13 species using the Neighbour-Joining method, which …

Evaluation Of The Xpert Carba-R Nxg Assay For Detection Of Carbapenemase Genes In A Global Challenge Set Of Pseudomonas Aeruginosa Isolates, Fred C. Tenover, Christian M. Gill, Tomefa E. Asempa, Isabella A. Tickler, Caitlin M. Dela Cruz, David P. Nicolau

Biology Faculty Publications

The growing prevalence and diversity of carbapenemase producers among carbapenem-resistant Pseudomonas aeruginosa (CRPA) isolates warrants an expansion of detection capabilities. The purpose of this study was to evaluate the performance of the commercially available Xpert Carba-R (Carba-R) and the research-use-only Xpert Carba-R NxG (Carba-R NxG) in a global collection of P. aeruginosa. The challenge set included 123 P. aeruginosa clinical isolates from 12 countries. Isolates were previously categorized via PCR or whole-genome sequencing. Carbapenemase classes tested include VIM, IMP, NDM, SPM, KPC, and GES. Non-carbapenemase (non-CP)-harboring isolates were also tested (negative control). Isolates were tested using the Carba-R NxG and …

Spatio-Temporal Dynamics Of Fungal Communities And Their Effects On Plants, Kel Cook

Biology ETDs

Fungi perform several critical functions in the environment. Spatiotemporal distributions of fungal communities will mediate when and where these functions happen and how they vary across the landscape. I first explored tropical tree canopy fungal community variation at small spatial scales and documented near total turnover of fungi across sub-meter distances and among adjacent substrates. The second chapter analyzed fungal turnover over the course of three years, where community stability was driven primarily by abundant fungi. In the third chapter, I tested effects of the environment, including host plant and habitat, on canopy fungal communities and found only small effects, …

The Impact Of Sample Processing And Media Chemistry On The Culturable Diversity Of Bacteria Isolated From A Cave, Katey E. Bender, Katelyn Glover, Alexander Archey, Hazel A. Barton

International Journal of Speleology

Although molecular approaches can identify members of microbial communities in the environment, genomic information does not necessarily correlate with environmental phenotype. Understanding functional roles can be done by cultivating representative species, yet the culturablility of bacteria from caves remains low, at 0.02%, limiting our understanding of microbial community interactions and processes. We have investigated several factors influencing culturability of bacteria from a single sample location in Maxwelton Sink Cave, WV, USA. Extended incubation of inoculated plates showed a significant increase in colony counts from two to four weeks, indicating that extended incubations increase culturability. There were no significant differences in …

Herb-Layer Dynamics In An Old-Growth Forest: Vegetation–Environment Relationships And Response To Invasion-Related Perturbations, Taylor M. Buskey, Margaret E. Maloney, Julia I. Chapman, Ryan W. Mcewan

Biology Faculty Publications

Temperate forests of eastern North America are subject to multiple invasions from non-native species that have the potential to drive long-term dynamics in biodiversity. Garlic mustard (Alliaria petiolata (M. Bieb.) Cavara and Grande) is an invasive plant in many deciduous forests, and management efforts often focus on removing this species to initiate native species restoration. Agrilus planipennis Fairmaire (emerald ash borer; Coleoptera: Buprestidae) is a non-native insect pest that has caused substantial loss of ash trees (Fraxinus spp. L.) in North America. Our goal was to understand how the herbaceous layer in an old-growth forest responded to the removal of …

Does The Presence Of Multiple Β-Lactamases In Gram-Negative Bacilli Impact The Results Of Antimicrobial Susceptibility Tests And Extended-Spectrum Β-Lactamase And Carbapenemase Confirmation Methods?, Fred C. Tenover, Caitlin M. Dela Cruz, Scott Dewell, Victoria M. Le, Isabella A. Tickler

Biology Faculty Publications

Objectives: Many multidrug-resistant Gram-negative bacilli (MDR-GNB) harbour multiple β-lactamases. The aim of this study was to assess the impact of multiple β-lactamase carriage on the accuracy of susceptibility tests and extended-spectrum β-lactamase (ESBL) and carbapenemase confirmation methods.

Methods: A total of 50 MDR-GNB, of which 29 carried multiple β-lactamases, underwent broth microdilution (BMD) and disk diffusion (DD) testing as well as confirmation tests for ESBLs and carbapenemases. Whole-genome sequencing (WGS) was used for β-lactamase gene identification.

Results: Categorical agreement of BMD and DD testing results ranged from 86.5 to 97.7% for 10 β-lactam agents. BMD and DD algorithms for ESBL …

The Influence Of Riparian Invasion By The Terrestrial Shrub Lonicera Maackii On Aquatic Macroinvertebrates In Temperate Forest Headwater Streams, Michelle N. Little, Kevin W. Custer, Eric B. Borth, Julia I. Chapman, Mitchell J. Kukla, Corey Kuminecz, Margaret E. Maloney, Michaela J. Woods, Ryan Mcewan

Biology Faculty Publications

The ecology of headwater streams is tightly linked to the riparian zone through organic matter subsidies which are highly susceptible to alteration due to biological invasion. Lonicera maackii is a non-native shrub that is a highly successful invader of headwater stream riparian zones in the American Midwest. We assessed effects on benthic macroinvertebrates across a gradient of invasion intensity from references sites with minimal invasion to a site that had a very heavy invasion. Benthic macroinvertebrates were sampled throughout the year and compositional differences were assessed using Non-metric Multidimensional Scaling ordination, and by comparing the prevalence of sensitive (Ephemeroptera, Plectoptera, …

Molecular Characterisation Of Hsp70 Gene Expression, Histopathology And Immune System Of Snakehead Fish, Channa Striata, Under Temperature And Bacterial Stress, Eid Elhussein Ihlam Ibrahim

Student Works (2020-2029)

Snakeheads are air-breathing freshwater fishes containing two genera, Channa (Asia) and Parachanna (Africa). The Asian genus is dominated by Channa striata which is found in southern and Southeastern parts of the continent. In this research, environmental and bacteria stressor to Channa striata were investigated. HSP70 gene was studied as an environmental stress gene (ChHSP70). Results showed a cDNA sequence of the gene to be (~918bp). It was also shown the gene is highly similar to that of other fish species. Constructing a phylogenetic tree of the gene across vertebrate species revealed six main clusters; same class remained conserved by showing …

Characterization Of The Overexpression Of The Native H+-Pumping Pyrophosphatase In The Microalga Picochlorum Soloecismus, Kimberly T. Wright

Biology ETDs

Microalgae are of interest for the creation of sustainable and cost competitive alternatives to petroleum-based fuels and chemicals. However, cultivation, extraction and processing of algal biomass requires improved yields to achieve economic feasibility. The advancement of microalgal biotechnology and various genetic engineering techniques allow the improvement of microalgae biomass for this purpose. Here, the characterization of the overexpression of the native vacuolar H+ pumping pyrophosphate (AVP1) in Picochlorum soloecismus was examined. AVP1 overexpression causes biomass increase in relevant plant crops. When overexpressed in this microalga it increases carbon storage in the form of starch in a closed laboratory photobioreactor. However, …

Inactivation Of Hippo And Cjun-N-Terminal Kinase (Jnk) Signaling Mitigate Fus Mediated Neurodegeneration In-Vivo, Ankita Sarkar, Abijeet Singh Mehta, Prajakta Deshpande, Madhuri Kango-Singh, Udai Bhan Pandey, Amit Singh

Biology Faculty Publications

Amyotrophic Lateral Sclerosis (ALS), a late-onset neurodegenerative disorder characterized by the loss of motor neurons in the central nervous system, has no known cure to-date. Disease causing mutations in human Fused in Sarcoma (FUS) leads to aggressive and juvenile onset of ALS. FUS is a well-conserved protein across different species, which plays a crucial role in regulating different aspects of RNA metabolism. Targeted misexpression of FUS in Drosophila model recapitulates several interesting phenotypes relevant to ALS including cytoplasmic mislocalization, defects at the neuromuscular junction and motor dysfunction. We screened for the genetic modifiers of human FUS-mediated neurodegenerative phenotype using molecularly …

Characterization Of The Broad-Spectrum Inhibitory Capability Of Alcaligenes Faecalis And A. Viscolactis Against Potential Pathogenic Microorganisms, Andrew Fuqua

Undergraduate Honors Theses

The recent rise of multidrug resistant microorganisms has grown from an isolated concern to a massive public health crisis. It has become imperative that scientists look for new ways to combat this issue. Due to the selective pressures of competition, bacteria and other microbes possess a host of defenses and weapons designed to exploit vulnerabilities in other microorganisms. Consequently, the study of these systems and microbial interactions has much to reveal in the search for novel antimicrobial treatments. Previous research from our laboratory has discovered that both Alcaligenes faecalis and Alcaligenes viscolactis, two rarely studied and generally non-virulent bacteria, …

Assessing The Influence Of Riparian Invasion By The Shrub Lonicera Maackii On Terrestrial Subsidies To Headwater Streams, Erin C. Rowekamp, Julia I. Chapman, Ryan Mcewan

Biology Faculty Publications

Invasion of Amur honeysuckle (Lonicera maackii) into riparian areas of headwater streams creates strong potential for alterations of terrestrial subsidies that may drive bottom-up effects on aquatic biota. In this study, we analyzed effects of L. maackii on terrestrial subsidies in stream sites that represented a gradient of invasion intensity in temperate deciduous forests of southwestern Ohio (USA). Leaf litter biomass, terrestrial and aquatic fine woody debris (0.5–9.9 cm diameter) volume and count, and terrestrial and aquatic coarse woody debris (>9.9 cm diameter) volume were analyzed. Based on previous research, we hypothesized that sites with a higher …

Antibiotic Resistant Bacteria, Antibiotic Resistance Genes And Potential Drivers In The Aquatic Environments, Shuo Shen

Dissertations

As antibiotic resistance genes in aquatic environment have been increasing across the world, affecting water quality and public health, many studies documented concentrations of antibiotic resistance genes and some studies discussed their potential drivers. However, systematic and quantitative reviews that link antibiotic resistance genes (ARGs) to anthropogenic and environmental factors are limited. Nevertheless, this information will be important for developing regulation policy on controlling antibiotic use and therefore reducing potential risks to antibiotic resistance. I conducted meta-analysis of ARGs concentration at a global scale using Bayesian inference to explore climatic and socio-economic factors as drivers. I found local-scale climatic variables …

Assessing Seed Handling Processes To Facilitate A Community-Engaged Approach To Regional Forest Restoration, Meredith Cobb, Michaela J. Woods, Ryan Mcewan

Biology Faculty Publications

In the Midwestern United States, there is a strong management impetus toward reforestation to replace trees lost to due to tree mortality and to establish forests on previously cleared properties. Here, we describe a public outreach and volunteer effort that aimed to generate positive, community-engaged restoration outcomes and report on a practical experiment involving seed handling. We obtained tree seeds that were donated by members of the community to local land managers. We evaluated the size of the seeds collected and tested the influence of common stratification media (none, sand and vermiculite) and seed size on germination success of three …

A Positive Feedback Loop Of Hippo- And C-Jun-Amino-Terminal Kinase Signaling Pathways Regulates Amyloid-Beta-Mediated Neurodegeneration, Madison Irwin, Meghana Tare, Aditi Singh, Oorvashi Roy Puli, Neha Gogia, Matthew Riccetti, Prajakta Deshpande, Madhuri Kango-Singh, Amit Singh

Biology Faculty Publications

Alzheimer's disease (AD, OMIM: 104300) is an age-related disorder that affects millions of people. One of the underlying causes of AD is generation of hydrophobic amyloid-beta 42 (Aβ42) peptides that accumulate to form amyloid plaques. These plaques induce oxidative stress and aberrant signaling, which result in the death of neurons and other pathologies linked to neurodegeneration. We have developed a Drosophila eye model of AD by targeted misexpression of human Aβ42 in the differentiating retinal neurons, where an accumulation of Aβ42 triggers a characteristic neurodegenerative phenotype. In a forward deficiency screen to look for genetic modifiers, we identified a molecularly …

Identification Of Uncommon Antibiotic-Producing Illinois Soil Isolates, Lesly Muniz, Dr. Lori Scott

Identifying and Characterizing Novel Antibiotic Producing Microbes From the Soil

This project is a collaboration with the Tiny Earth Project Initiative (TEPI), which is a global network of educators and students focused on student sourcing antibiotic discovery from the soil. We researched tester strains B. subtilis and E. coli from the soil isolates obtained. We further verified if the isolates were common antibiotic bacteria. Unfortunately, this project heavily relied on biochemical tests, colony morphology, and Gram stains to reject or fail to reject our hypothesis. Our goal was to discover new antibiotic-producing bacteria that could be beneficial in combating ESKAPE strains. A proper PCR and DNA extraction would be required …