Bacterial Infections and Mycoses Commons^™

Antiviral Activity And Mucosal Safety Of Novel Human-Milk-Inspired Antimicrobial Peptides, Nazita Yousefieh, Louise A. Ouattara, Maimoona Bhutta, Ishita M. Shah, Carolina Herrera, Gustavo F. Doncel

CONRAD Publications

Background: Sexually transmitted infections (STIs) remain a major global health concern, with over one million new curable cases reported daily and limited long-term treatment options. Additionally, there are limited treatment options for women with bacterial vaginosis (BV), a dysbiotic condition predisposing them to STIs. Computationally designed human-milk-inspired antimicrobial peptides (AMPs) are promising candidates for novel antiviral and antibacterial therapies. This study evaluated the cervicovaginal mucosal safety and antiviral activity of three human-milk-inspired AMPs (MAT-006, UCD-MAT-001, and UCD-MAT-002) previously shown to exhibit antimicrobial activity against BV-causing pathogens. Methods: AMP cytotoxicity and inflammatory responses were assessed in relevant genital tract cell lines …

A Scalable Paper-Based Electrochemical Sensor Employing Mwcnts For Isoniazid Detection, Sri Ramulu Torati, Gymama Slaughter

Center for Bioelectronics Publications

Isoniazid (INZ) is an antimicrobial agent that treats tuberculosis by inhibiting the InhA enzyme in Mycobacterium tuberculosis, making sensitive and reliable methods for routine monitoring essential to ensure safe and effective therapy. We report the development of a novel paper-based electrochemical sensor for the sensitive and selective detection of isoniazid. The sensor is constructed using a gold inkjet-printed electrode (GIPE) modified with gold nanoparticles (AuNPs), chitosan (CH), and multi-walled carbon nanotubes (MWCNTs), forming a GIPE/AuNPs/CH/MWCNTs sensor. Electrochemical deposition of AuNPs effectively addressed insulating gaps generated during the sintering of the gold ink, enhancing electrical conductivity and surface uniformity. The …

Cultures For Acid-Fast Bacilli: Are We Being Good Stewards?, Jennifer Hanrahan, Julie D. Sill, Patricia Ver Schneider, Jessica F. Copeland, Elsie Frimpongmaa Amoako-Kissi, Ogochukwu O. Ilobi, Angela J. Toepp

Department of Medicine Faculty Publications

Objective: To describe the use of cultures for acid-fast bacilli (AFB) and situations in which AFB cultures are unlikely to be of clinical benefit.

Design: Retrospective descriptive study of AFB cultures submitted to Sentara Health microbiology laboratory from December 1, 2021, to December 1, 2023. Data were collected from the electronic medical record and included patient demographics, the service line that ordered the culture, specimen source, and culture results.

Setting: Sentara Healthcare System.

Patients: All patients who had specimens submitted to the microbiology laboratory during the study period were included.

Results: A total of 13,944 AFB cultures from 8,243 …

Reiq-Mediated Alarmone Signalling Regulates Growth, Stress-Induced Biofilm Formation And Spore Accumulation In Clostridioides Difficile, Areej Malik, Adenrele Oludiran, Asia Poudel, Orlando Berumen Alvarez, Charles Woodward, Erin B. Purcell

Chemistry & Biochemistry Faculty Publications

The bacterial stringent response (SR) is a conserved transcriptional reprogramming pathway mediated by the nucleotide signalling alarmones, (pp)pGpp. The SR has been implicated in antibiotic survival in Clostridioides difficile, a biofilm- and spore-forming pathogen that causes resilient, highly recurrent C. difficile infections. The role of the SR in other processes and the effectors by which it regulates C. difficile physiology are unknown. C. difficile RelQ is a clostridial alarmone synthetase. Deletion of relQ dysregulates C. difficile growth in unstressed conditions, affects susceptibility to antibiotic and oxidative stressors and drastically reduces biofilm formation. While wild-type C. difficile displays increased biofilm …

Machine-Learning-Enabled Diagnostics With Improved Visualization Of Disease Lesions In Chest X-Ray Images, Md. Fashiar Rahman, Tzu-Liang (Bill) Tseng, Michael Pokojovy, Peter Mccaffrey, Eric Walser, Scott Moen, Alex Vo, Johnny C. Ho

Mathematics & Statistics Faculty Publications

The class activation map (CAM) represents the neural-network-derived region of interest, which can help clarify the mechanism of the convolutional neural network’s determination of any class of interest. In medical imaging, it can help medical practitioners diagnose diseases like COVID-19 or pneumonia by highlighting the suspicious regions in Computational Tomography (CT) or chest X-ray (CXR) film. Many contemporary deep learning techniques only focus on COVID-19 classification tasks using CXRs, while few attempt to make it explainable with a saliency map. To fill this research gap, we first propose a VGG-16-architecture-based deep learning approach in combination with image enhancement, segmentation-based region …

Nanosecond Pulsed Electric Fields Increase Antibiotic Susceptibility In Methicillin-Resistant Staphylococcus Aureus, Alexandra E. Chittams-Miles, Areej Malik, Erin B. Purcell, Claudia Muratori

Bioelectrics Publications

Staphylococcus aureus is the leading cause of skin and soft-tissue infections (SSTIs). SSTIs caused by bacteria resistant to antimicrobials, such as methicillin-resistant S. aureus (MRSA), are increasing in incidence and have led to higher rates of hospitalization. In this study, we measured MRSA inactivation by nanosecond pulsed electric fields (nsPEF), a promising new cell ablation technology. Our results show that treatment with 120 pulses of 600 ns duration (28 kV/cm, 1 Hz), caused modest inactivation, indicating cellular damage. We anticipated that the perturbation created by nsPEF could increase antibiotic efficacy if nsPEF were applied as a co-treatment. To test this …

Salmonella Detection In Food Using A Hek-Htlr5 Reported Cell-Based Sensor, Esma Eser, Victoria A. Felton, Rishi Drolia, Arun K. Bhunia

Biological Sciences Faculty Publications

The development of a rapid, sensitive, specific method for detecting foodborne pathogens is paramount for supplying safe food to enhance public health safety. Despite the significant improvement in pathogen detection methods, key issues are still associated with rapid methods, such as distinguishing living cells from dead, the pathogenic potential or health risk of the analyte at the time of consumption, the detection limit, and the sample-to-result. Mammalian cell-based assays analyze pathogens’ interaction with host cells and are responsive only to live pathogens or active toxins. In this study, a human embryonic kidney (HEK293) cell line expressing Toll-Like Receptor 5 (TLR-5) …

Clonal Diversity, Antibiotic Resistance, And Virulence Factor Prevalence Of Community Associated Staphylococcus Aureus In Southeastern Virginia, Katelyn D. Cranmer, Mohan D. Pant, Suzanne Quesnel, Julia A. Sharp

EVMS School of Health Professions Faculty Publications

Staphylococcus aureus is a significant human pathogen with a formidable propensity for antibiotic resistance. Worldwide, it is the leading cause of skin and soft tissue infections (SSTI), septic arthritis, osteomyelitis, and infective endocarditis originating from both community- and healthcare associated settings. Although often grouped by methicillin resistance, both methicillin-resistant (MRSA) and methicillin-sensitive (MSSA) strains are known to cause significant pathologies and injuries. Virulence factors and growing resistance to antibiotics play major roles in the pathogenicity of community-associated strains. In our study, we examined the genetic variability and acquired antibiograms of 122 S. aureus clinical isolates from SSTI, blood, and urinary …

Study Of Glucose Supplementation On Antibiotic Efficacy Against Staphylococcus Aureus, Areej Malik, Alexandra E. Chittams-Miles, Claudia Muratori, Erin B. Purcell

College of Sciences Posters

Staphylococcus aureus (S. aureus), is a Gram-positive, facultative anaerobic, biofilm-forming bacterium. It is the leading cause of skin and soft tissue infections (SSTIs) in the United States. The public health impact of S. aureus has been increased by the emergence of Methicillin-resistant Staphylococcus aureus. It has also shown intermediate resistance to Vancomycin, which suggests that full resistance may develop. It is known that hyperglycemia (high blood sugar) from diabetes reduces immune system function. Patients with diabetes experience a greater rate of skin and soft tissue infections. This research explores the effect of increasing glucose concentration on S. …

Incidence And Potential Co-Morbidities In Facial Pigmentary Demarcation Lines In Indian Populations, Lakkireddygari Sujana, Savitha L. Beergouder, Alekhya Rallapalli, Sujatha Alla, Prasanthi Chidipudi

Engineering Management & Systems Engineering Faculty Publications

Background: The most noticeable part of human body is face. The obvious boundaries on the skin known as Pigmentary Demarcation Lines (PDL) found over face and have clear borders of abrupt transition between more hyper-pigmented skin and areas of normal skin pigmentation due to differences in melanocyte distribution that may be influenced by multiple factors. Facial pigmentary demarcation lines (PDL) directly reflect on patient’s physical appearance and self-image as they may contribute to dysmorphism and even central to depressive illness in susceptible individuals posing cosmetic concern for the patient and a challenge for dermatologist. Therefore, it is important for early …

Orofacial Manifestations Of Lyme Disease: A Systematic Review, Brenda Bradshaw, Kelsey M. Jones, Joleen M. Westerdale-Mcinnis, Holly Gaff

Dental Hygiene Faculty Publications

Purpose: Orofacial manifestations of Lyme disease can affect head and neck anatomical structures that are frequently examined by dental professionals. The purpose of this systematic review was to examine the literature for types and frequencies of orofacial manifestations documented in populations in the United States (US) with Lyme disease.

Methods: Four electronic databases (Dentistry and Oral Sciences, PubMed, Cinahl Plus, and Medline) were systematically searched during the summer of 2019 using keywords and MeSH terms to identify relevant studies. Search term alterations and synonyms were cross-checked using the US National Library of Medicine Unified Medical Language System Metathesaurus. Full-text, English …

Antimicrobial Efficacy And Safety Of A Novel Gas Plasma-Activated Catheter Lock Solution, Sudhir Bhatt, Poonam Mehta, Chen Chen, Dayle A. Daines, Leonard A. Mermel, Hai-Lan Chen, Michael G. Kong

Bioelectrics Publications

Antimicrobial lock solutions are important for prevention of microbial colonization and infection of long-term central venous catheters. We investigated the efficacy and safety of a novel antibiotic-free lock solution formed from gas plasma-activated disinfectant (PAD). Using a luminal biofilm model, viable cells of methicillin-resistant Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, and Candida albicans in mature biofilms were reduced by 6 to 8 orders of magnitude with a PAD lock for 60 min. Subsequent 24-h incubation of PAD-treated samples resulted in no detectable regrowth of viable bacteria or fungi. As a comparison, the use of a minocycline-EDTA-ethanol lock solution for 60 …

Gas Plasma Pre-Treatment Increases Antibiotic Sensitivity And Persister Eradication In Methicillin-Resistant Staphylococcus Aureus, Li Guo, Ruobing Xu, Yiming Zhao, Dingxin Liu, Zhijie Liu, Xiaohua Wang, Hailan Chen, Michael G. Kong

Bioelectrics Publications

Methicillin-resistant Staphylococcus aureus (MRSA) is a major cause of serious nosocomial infections, and recurrent MRSA infections primarily result from the survival of persister cells after antibiotic treatment. Gas plasma, a novel source of ROS (reactive oxygen species) and RNS (reactive nitrogen species) generation, not only inactivates pathogenic microbes but also restore the sensitivity of MRSA to antibiotics. This study further found that sublethal treatment of MRSA with both plasma and plasma-activated saline increased the antibiotic sensitivity and promoted the eradication of persister cells by tetracycline, gentamycin, clindamycin, chloramphenicol, ciprofloxacin, rifampicin, and vancomycin. The short-lived ROS and RNS generated by plasma …

Hydrocortisone, Vitamin C And Thiamine For The Treatment Of Severe Sepsis And Septic Shock: A Retrospective Before-After Study, Paul E. Marik, Vikramjit Khangoora, Racquel Rivera, Michael H. Hooper, John Catravas

Bioelectrics Publications

BACKGROUND: The global burden of sepsis is estimated as 15 to 19 million cases annually with a mortality rate approaching 60% in low income countries.

METHODS: In this retrospective before-after clinical study, we compared the outcome and clinical course of consecutive septic patients treated with intravenous vitamin C, hydrocortisone and thiamine during a 7-month period (treatment group) compared to a control group treated in our ICU during the preceding 7 months. The primary outcome was hospital survival. A propensity score was generated to adjust the primary outcome.

FINDINGS: There were 47 patients in both treatment and control groups with no …

Invasion Of Two Tick-Borne Diseases Across New England: Harnessing Human Surveillance Data To Capture Underlying Ecological Invasion Processes, Katharine S. Walter, Kim M. Pepin, Colleen T. Webb, Holly D. Gaff, Peter J. Krause, Virginia E. Pitzer, Maria A. Diuk-Wasser

Biological Sciences Faculty Publications

Modelling the spatial spread of vector-borne zoonotic pathogens maintained in enzootic transmission cycles remains a major challenge. The best available spatio-temporal data on pathogen spread often take the form of human disease surveillance data. By applying a classic ecological approach-occupancy modelling-to an epidemiological question of disease spread, we used surveillance data to examine the latent ecological invasion of tick-borne pathogens. Over the last half-century, previously undescribed tick-borne pathogens including the agents of Lyme disease and human babesiosis have rapidly spread across the northeast United States. Despite their epidemiological importance, the mechanisms of tick-borne pathogen invasion and drivers underlying the distinct …

Tick-Bourne Pathogens Of Potential Zoonotic Importance In The Southern African Region, Simbarashe Chitanga, Holly Gaff, Samson Mukaratirwa

Biological Sciences Faculty Publications

The aim of this communication is to provide preliminary information on the tick-borne pathogens of potential zoonotic importance present in southern Africa, mainly focusing on their geographical distribution and host range, and to identify research gaps. The following tick-borne zoonoses have been reported to occur in southern Africa based mainly on case reports: Crimean–Congo haemorrhagic fever caused by Crimean–Congo haemorrhagic fever virus; ehrlichiosis caused by Ehrlichia ruminantium, Ehrlichia canis and Anaplasma phagocytophilum; babesiosis caused by Babesia microti; relapsing fever caused by Borrelia duttonii and rickettsioses caused by Rickettsia africae, Rickettsia aeschlimannii and Rickettsia conorii. The …

Estimating The Reproductive Numbers For The 2008-2009 Cholera Outbreaks In Zimbabwe, Zindoga Mukandavire, Shu Liao, Jin Wang, Holly Gaff, David L. Smith, J. Glenn Morris Jr.

Biological Sciences Faculty Publications

Cholera remains an important global cause of morbidity and mortality, capable of causing periodic epidemic disease. Beginning in August 2008, a major cholera epidemic occurred in Zimbabwe, with 98,585 reported cases and 4,287 deaths. The dynamics of such outbreaks, particularly in nonestuarine regions, are not well understood. We explored the utility of mathematical models in understanding transmission dynamics of cholera and in assessing the magnitude of interventions necessary to control epidemic disease. Weekly data on reported cholera cases were obtained from the Zimbabwe Ministry of Health and Child Welfare (MoHCW) for the period from November 13, 2008 to July 31, …

Results From A Mathematical Model For Human Monocytic Ehrlichiosis, H. Gaff, L. Gross, E. Schaefer

Biological Sciences Faculty Publications

Human monocytic ehrlichiosis (Ehrlichia chaffeensis), HME, is a tick-transmitted, rickettsial disease that has recently increased substantially in the USA from 142 reported cases in 2001 to 506 reported cases in 2005 [1,2]. There have been increasing surveys of tick populations over the past 10 years that have in turn supported the development of models for tick-borne disease transmission. Resulting HME models [3] suggest the importance of metapopulation structures, landscape environment parameters and periodic climatic effects in predicting the dynamics of HME transmission and the efficacy of control efforts, such as the reduction of the tick population through acaricide …

Characterization Of Β-Lactam Resistant Pandemic Serotypes Of Vibrio Cholerae Isolated From Ships' Ballast Tanks And Coastal Waters, Amanda Lynn Goodrich

OES Theses and Dissertations

Vibrio cholerae serotypes 01 and 0139 are responsible for world-wide epidemics of cholera. These pandemic causing strains must possess genes that encode for the cholera toxin (CTX) and toxin co-regulated pili (TCP) in order to infect their hosts. In this study, 284 isolates of Vibrio cholerae from ballast and coastal waters were serotyped, with 11 % testing positive for serotype 01 and 21 % testing positive for serotype 0139. PCR assays were used to detect the presence of ctxA and tcpA genes in all positive isolates, none of which contained ctxA while 2% of the isolates contained tcpA. The 01 …

Bacillus Anthracis Virulent Plasmid Px02 Genes Found In Large Plasmids Of Two Other Bacillus Species, Vicki A. Luna, Debra S. King, K. Kealy Peak, Frank Reeves, Lea Heberlein-Larson, William Veguilla, L. Heller, Kathleen E. Duncan, Andrew C. Cannons, Philip Amuso, Jacqueline Cattani

Bioelectrics Publications

In order to cause the disease anthrax, Bacillus anthracis requires two plasmids, pX01 and pX02, which carry toxin and capsule genes, respectively, that are used as genetic targets in the laboratory detection of the bacterium. Clinical, forensic, and environmental samples that test positive by PCR protocols established by the Centers for Disease Control and Prevention for B. anthracis are considered to be potentially B. anthracis until confirmed by culture and a secondary battery of tests. We report the presence of 10 genes (acpA, capA, capB, capC, capR, capD, IS1627, ORF 48, ORF 61, and repA) and the sequence for the …

Comparison Of Methods For Dna Isolation From Food Samples For Detection Of Shiga Toxin-Producing Escherichia Coli By Real-Time Pcr, Loree C. Heller, Carisa R. Davis, K. Kealy Peak, David Wingfield, Andrew C. Cannons, Philip T. Amuso, Jacqueline Cattani

Bioelectrics Publications

In this study, food samples were intentionally contaminated with Escherichia coli O157:H7, and then DNA was isolated by using four commercial kits. The isolated DNA samples were compared by using real-time PCR detection of the Shiga toxin genes. The four kits tested worked similarly.