Cell and Developmental Biology Commons^™

Npgreat: Assembly Of The Human Subtelomere Regions With The Use Of Ultralong Nanopore Reads And Linked Reads, Eleni Adam, Desh Ranjan, Harold Riethman

Computer Science Faculty Publications

Background: Human subtelomeric DNA regulates the length and stability of adjacent telomeres that are critical for cellular function, and contains many gene/pseudogene families. Large evolutionarily recent segmental duplications and associated structural variation in human subtelomeres has made complete sequencing and assembly of these regions difficult to impossible for many loci, complicating or precluding a wide range of genetic analyses to investigate their function.

Results: We present a hybrid assembly method, NanoPore Guided REgional Assembly Tool (NPGREAT), which combines Linked-Read data with mapped ultralong nanopore reads spanning subtelomeric segmental duplications to potentially overcome these difficulties. Linked-Read sets of DNA sequences identified …

A Pooling Strategy For Detecting Carbapenem Resistance Genes By The Xpert Carba-R Test In Rectal Swab Specimens, Fred C. Tenover, Peng Zhang, Qi Wang, Chaoe Zhou, Feifei Zhang, Xinghui Gao, Yi-Wei Tang, Hui Wang

Biology Faculty Publications

Rapid and accurate detection of carriers of carbapenemase-producing organisms (CPO) in hospitalized patients is critical for infection control and prevention. This study aimed to evaluate a pooling strategy for the detection of carbapenem resistance genes (CRG) in multiple specimens using the Xpert Carba-R test. Two rectal swabs each were collected from 415 unique patients. One swab was tested by Carba-R on the five specimen-pooled strategy. The other swab was tested individually by culture followed by DNA sequence analysis for CRG as the reference. At the first 5:1 pooling testing, 22 of 83 pools were positive, which yielded 34 positives from …

Temporal Trends In Lipoprotein(A) Concentrations: The Atherosclerosis Risk In Communities Study, Matthew R. Deshotels, Caroline Sun, Vijay Nambi, Salim S. Virani, Kunihiro Matsushita, Bing Yu, Christie . M. Ballantyne, Ron C. Hoogeveen

Office of the Provost

Background: Plasma lipoprotein(a) (Lp[a]) concentrations are primarily determined by genetic factors and are believed to remain stable throughout life. However, data are scarce on longitudinal trends in Lp(a) concentrations over time. Therefore, it is unclear whether measurement of Lp(a) once in a person's life is sufficient for cardiovascular risk assessment in all adults.
Methods and Results: Lp(a) concentrations, specifically apolipoprotein(a) concentrations, were measured at visits 4 and 5, ≈15 years apart, in 4734 adult participants of the ARIC (Atherosclerosis Risk in Communities) study (mean age at visits 4 and 5, 60.7±5.1 and 75.5±5.2 years, respectively). Participants were categorized by baseline …

The Genetics Of Skin Cancer: What Genes Drive The Development Of Basal Cell Carcinoma, Squamous Cell Carcinoma, And Melanoma?, Cassandra Poole, Abagail Pack, Elizabeth Whitehead, Virginia Marshall

Spring Showcase for Research and Creative Inquiry

Skin cancer is one of the most common forms of cancer worldwide. The American Academy of Dermatology estimates that 9500 people in the United States are diagnosed with skin cancer every day, and that 1 in 5 Americans will be diagnosed with skin cancer by age 70. With such a high prevalence of disease, understanding how skin cancer develops and how it can be treated is extremely important. This project aims to analyze the genes involved in the development of the three most common forms of skin cancer: basal cell carcinoma, squamous cell carcinoma, and melanoma.

Leaf Phenology And Freeze Tolerance Of The Invasive Tree Pyrus Calleryana (Roseaceae) And Potential Native Competitors, Margaret E. Maloney, Abby Hay, Eric B. Borth, Ryan W. Mcewan

Biology Faculty Publications

Pyrus calleryana is one of the most problematic invasive species in the eastern United States. The mechanisms that enable Py. calleryana to establish and outcompete native plants are not fully understood but likely include a profile of advantageous traits. Extended leaf phenology is a characteristic noted in many woody invasive plants. Leaf phenology of Py. calleryana and two native woody species, Populus deltoides and Platanus occidentalis, was observed in natural areas near Dayton, OH from December 2019 to November 2020. A frost event in May also gave us the serendipitous opportunity to assess frost tolerance of these species. We …

Mechanisms Of Carbapenemase-Mediated Resistance Among High-Risk Pseudomonas Aeruginosa Lineages In Peru, Isabella A. Tickler, Juan Carlos Gomez De La Torre, Luis Alvarado, Anne E. Obradovich, Fred C. Tenover

Biology Faculty Publications

Objectives: Pseudomonas aeruginosa is one of the leading causes of healthcare-associated infections globally. High-risk carbapenemase-encoding P. aeruginosa clones are disseminating in many regions. The aim of this study was to learn more about the lineages and mechanisms of resistance of P. aeruginosa circulating in Peru.

Methods: A total of 141 carbapenemase-producing isolates recovered from hospitalized and ambulatory patients in Lima were sequenced and analyzed to infer their lineages through whole-genome sequence typing (wgST) and to identify their antimicrobial resistance genes.

Results: wgST identified nine sequence types (STs); ST111 and ST357 were the most frequently encountered (44.0% and 38.3%, respectively), followed …

Resolving The Repression Pathway Of Virulence Gene Hila In Salmonella, Alexandra King, Lon Chubiz Phd, Brenda Pratte, Lauren Daugherty

Undergraduate Research Symposium

Salmonella is a relatively abundant, virulent species of bacteria that is most known for spreading gastrointestinal diseases through food. These illnesses result in approximately 1.35 million infections, including over 25,000 hospitalizations each year, in the U.S. alone (CDC.gov). As antibiotic resistance becomes an increasingly urgent public health problem, the importance of developing alternative treatment methods is only becoming more crucial. One of the genes responsible for this virulence is known as hilA. HilA is the main transcriptional regulator of Salmonella Pathogenicity Island-1 gene (UniProt). SPI-1 plays an important role in the invasion of Salmonella into epithelial cells. The proteins encoded …

When Problems Become Solutions: Harnessing The Osteogenic Capacity Of Disease-Causing Stem Cells To Repair Bone Fractures, Mehreen Pasha

University Scholar Projects

While we often perceive disease as negative, there is potential to engineer seemingly negative biological phenomena into therapeutics to treat a variety of human illnesses. Fibrodysplasia ossificans progressiva (FOP) is a genetic disorder involving uncontrolled, widespread, extraskeletal bone growth, or heterotopic ossification (HO). In FOP patients, stem cells called fibro/adipogenic progenitors (FAPs) follow an abnormal, osteogenic pathway. In the present study, we investigate whether we can adapt these Acvr1 mutant FAPs, which are exceptional at producing bone, to repair bone fractures in otherwise normal patients. The primary aims of this study are (1) to devise and optimize a novel method …

When Problems Become Solutions: Harnessing The Osteogenic Capacity Of Disease-Causing Stem Cells To Repair Bone Fractures, Mehreen Pasha

Honors Scholar Theses

While we often perceive disease as negative, there is potential to engineer seemingly negative biological phenomena into therapeutics to treat a variety of human illnesses. Fibrodysplasia ossificans progressiva (FOP) is a genetic disorder involving uncontrolled, widespread, extraskeletal bone growth, or heterotopic ossification (HO). In FOP patients, stem cells called fibro/adipogenic progenitors (FAPs) follow an abnormal, osteogenic pathway. In the present study, we investigate whether we can adapt these Acvr1 mutant FAPs, which are exceptional at producing bone, to repair bone fractures in otherwise normal patients. The primary aims of this study are (1) to devise and optimize a novel method …

Characterization Of SccMec Instability In Methicillin-Resistant Staphylococcus Aureus Affecting Adjacent Chromosomal Regions, Including The Gene For Staphylococcal Protein A (Spa), Isabella A. Tickler, Fred C. Tenover, C. R. Scharn, R. V. Goering

Biology Faculty Publications

Staphylococcal cassette chromosome mec (SCCmec) represents a sequence of clear clinical and diagnostic importance in staphylococci. At a minimum the chromosomal cassette contains the mecA gene encoding PBP2a but frequently also includes additional antibiotic resistance genes (e.g., ermA and aadC; macrolide and aminoglycoside resistance, respectively). Certain regions within SCCmec elements are hot spots for sequence instability due to cassette-specific recombinases and a variety of internal mobile elements. SCCmec changes may affect not only cassette stability but the integrity of adjacent chromosomal sequences (e.g., the staphylococcal protein A gene; spa). We investigated SCCmec stability …

Carbapenemase-Producing Pseudomonas Aeruginosa – An Emerging Challenge, Fred C. Tenover, David P. Nicolau, Christian M. Gill

Biology Faculty Publications

Carbapenem-resistant Pseudomonas aeruginosa (CR-PA) is a major healthcare-associated pathogen worldwide. In the United States, 10–30% of P. aeruginosa isolates are carbapenem-resistant, while globally the percentage varies considerably. A subset of carbapenem-resistant P. aeruginosa isolates harbour carbapenemases, although due in part to limited screening for these enzymes in clinical laboratories, the actual percentage is unknown. Carbapenemase-mediated carbapenem resistance in P. aeruginosa is a significant concern as it greatly limits the choice of anti-infective strategies, although detecting carbapenemase-producing P. aeruginosa in the clinical laboratory can be challenging. Such organisms also have been associated with nosocomial spread requiring infection prevention interventions. The carbapenemases …

Escherichia Coli Alanyl-Trna Synthetase Maintains Proofreading Activity And Translational Accuracy Under Oxidative Stress, Arundhati Kavoor, Paul Kelly, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Aminoacyl-tRNA synthetases (aaRSs) are enzymes that synthesize aminoacyl-tRNAs to facilitate translation of the genetic code. Quality control by aaRS proofreading and other mechanisms maintains translational accuracy, which promotes cellular viability. Systematic disruption of proofreading, as recently demonstrated for alanyl-tRNA synthetase (AlaRS), leads to dysregulation of the proteome and reduced viability. Recent studies showed that environmental challenges such as exposure to reactive oxygen species can also alter aaRS synthetic and proofreading functions, prompting us to investigate if oxidation might positively or negatively affect AlaRS activity. We found that while oxidation leads to modification of several residues in Escherichia coli AlaRS, unlike …

Detection Of Methicillin-Resistant Staphylococcus Aureus Infections Using Molecular Methods, Fred C. Tenover, Isabella A. Tickler

Biology Faculty Publications

The application of molecular detection methods for bacterial pathogens has dramatically improved the outcomes of septic patients, including those with methicillin-resistant Staphylococcus aureus (MRSA) infections. Molecular methods can be applied to a variety of clinical specimens including nasal swabs, growth in blood culture bottles, and wounds. While data show that the overall accuracy of molecular tests for MRSA is high, results can be confounded by the presence of multiple staphylococcal species in a specimen, insertions and deletions of DNA in and around the Staphylococcal Cassette Chromosome mec (SCCmec) element, and point mutations in mecA. Herein, we explore the complexities of …

Clinical Performance Of The Xpert® Ct/Ng Test For Detection Of Chlamydia Trachomatis And Neisseria Gonorrhoeae: A Multicenter Evaluation In Chinese Urban Hospitals, Fred C. Tenover, Yan Han, Mei-Qin Shi, Qing-Ping Jiang, Wen-Jing Le, Xiao-Lin Qin, Han-Zhen Xiong, He-Ping Zheng, Yi-Wei Tang, Yue-Ping Yin

Biology Faculty Publications

Background: We aimed to evaluate the clinical performance of the GeneXpert® (Xpert) CT/NG assay for the detection of Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) using urine and cervical swabs collected from patients in China.

Methods: This study was conducted from September 2016 to September 2018 in three Chinese urban hospitals. The results from the Xpert CT/NG test were compared to those from the Roche cobas® 4800 CT/NG test. Discordant results were confirmed by DNA sequence analysis.

Results: In this study, 619 first void urine (FVU) specimens and 1,042 cervical swab specimens were included in the final dataset. There were …