Pathogenic Microbiology Commons^™

Histidine-Triad Hydrolases Provide Resistance To Peptide-Nucleotide Antibiotics., Eldar Yagmurov, Darya Tsibulskaya, Alexey Livenskyi, Marina Serebryakova, Yury I Wolf, Sergei Borukhov, Konstantin Severinov, Svetlana Dubiley

Rowan-Virtua School of Osteopathic Medicine Departmental Research

The Escherichia coli microcin C (McC) and related compounds are potent Trojan horse peptide-nucleotide antibiotics. The peptide part facilitates transport into sensitive cells. Inside the cell, the peptide part is degraded by nonspecific peptidases releasing an aspartamide-adenylate containing a phosphoramide bond. This nonhydrolyzable compound inhibits aspartyl-tRNA synthetase. In addition to the efficient export of McC outside the producing cells, special mechanisms have evolved to avoid self-toxicity caused by the degradation of the peptide part inside the producers. Here, we report that histidine-triad (HIT) hydrolases encoded in biosynthetic clusters of some McC homologs or by standalone genes confer resistance to McC-like …

Fungicide Sensitivity Of Sclerotinia Sclerotiorum Isolates Selected From Five Different States That Use Different Fungicide Treatments, Cristian Wulkop Gil

UCARE: Research Products

Sclerotinia sclerotiorum is a plant pathogenic fungus that causes a disease called white mold that can infect more than 450 plant species including soybeans, dry beans, green beans, canola, and sunflower. This pathogen is capable of up to $252M in losses every year (U.S. Canola Association, 2014). Fungicides are widely used in developed agricultural systems to control disease. However, resistance to the most effective fungicides has emerged and spread in pathogen populations and there have been multiple reports of S. sclerotiorum isolates becoming resistant to certain fungicides. Since different fields in different states use different fungicide treatments on plants and …

Exosomes In Transmission And Blocking Of Arthropod-Borne Flaviviral Infection And Pathogenesis, Wenshuo Zhou

Biomedical Sciences Theses & Dissertations

Vector-borne diseases (VBDs) are human illnesses that are transmitted by vectors such as ticks, mosquitoes, and fleas. These arthropods transmit infectious pathogens such as viruses, protozoa, and bacteria, to humans during their blood-feeding. According to the estimation of the WHO, billions of people are affected by VBDs worldwide, and about 700,000 deaths are reported annually. Currently, very few reliable VBDs control approaches and vaccines available to treat various VBDs. Additionally, approaches to control arthropod’ proliferation and migration are difficult to develop. Furthermore, molecular determinants and mechanisms for the transmission are poorly understood. This work describes two studies identifying the novel …

On The Inadequacy Of Species Distribution Models For Modelling The Spread Of Sars-Cov-2: Response To Araújo And Naimi, Joseph D. Chipperfield, Blas M. Benito, Robert B. O'Hara, Richard J. Telford, Colin J. Carlson

United States Public Health Resources

The ongoing pandemic of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is causing significant damage to public health and economic livelihoods, and is putting significant strains on healthcare services globally. This unfolding emergency has prompted the preparation and dissemination of the article “Spread of SARS-CoV-2 Coronavirus likely to be constrained by climate” by Araújo and Naimi (2020). The authors present the results of an ensemble forecast made from a suite of species distribution models (SDMs), where they attempt to predict the suitability of the climate for the spread of SARS-CoV-2 over the coming months. They argue that climate is …

Comparison Of Five Methods For Detection Of Extended Spectrum Β-Lactamases In Gram Negative Enteric Bacteria, Mahmood Z. Al-Hasso, Subhi H. Khalaf

Karbala International Journal of Modern Science

The presence of extended-spectrum β-lactamases in 55 isolates of Gram negative enteric bacteria isolated from lower respiratory tract infections, was investigated by using the Clinical Laboratory Standards Institute CLSI method which showed that 41.8% of the isolates produced this type of β-lactamases, and that Klebsiella pneumoniae isolates were the most producing species with a production rate of 61.1%, followed by Escherichia coli isolates 43.75%. Five confirmatory methods were used to detect these enzymes: ceftazidime agar method, double-disk synergy method, combination disk method, modified 3D extract method and enzymatic disks method. The study indicated that ceftazidime agar method was the best …

Listeria Monocytogenes Response To Anaerobic Environments, Brandy N. Roberts, Damayanti Chakravarty, J.C. Gardner Iii, Steven C. Ricke, Janet R. Donaldson

Faculty Publications

Listeria monocytogenes is a Gram-positive facultative anaerobic bacterium that is responsible for the disease, listeriosis. It is particularly lethal in pregnant women, the fetus, the elderly and the immunocompromised. The pathogen survives and replicates over a wide range of temperatures (4 to 42 °C), pH, salt and oxygen concentrations. Because it can withstand various environments, L. monocytogenes is a major concern in food processing industries, especially in dairy products and ready-to-eat fruits, vegetables and deli meats. The environment in which the pathogen is exposed can influence the expression of virulence genes. For instance, studies have shown that variations in oxygen …

Gene Expression Analysis Of Effectors Involved In Early Interaction Of Banana And Fusarium Oxysporum F. Sp. Cubense, Nee Kiew Poon

Student Works (2020-2029)

Banana is a popular but disease-laden fruit crop. It is very susceptible to various phytopathogens such as viruses, bacteria, fungi and nematodes. A particularly infectious and economically important fungal disease in banana is Fusarium wilt caused by Fusarium oxysporum f. sp. cubense (Foc). The disease has been plaguing the banana industry since late 19th century. Despite the early discovery of this phytopathogen of banana, little is known on its the mechanism of pathogenicity. In other plants, fungal effectors have been found to function in manipulating plant mechanisms during infection and many have been identified and characterized. In this study, the …

A High-Fat/High-Protein, Atkins-Type Diet Exacerbates Clostridioides (Clostridium) Difficile Infection In Mice, Whereas A High-Carbohydrate Diet Protects, Chrisabelle C. Mefferd, Shrikant S. Bhute, Jacqueline R. Phan, Jacob V. Villarama, Dung M. Do, Stephanie Alarcia, Ernesto Abel-Santos, Brian P. Hedlund

Chemistry and Biochemistry Faculty Research

Clostridioides difficile (formerly Clostridium difficile) infection (CDI) can result from the disruption of the resident gut microbiota. Western diets and popular weight-loss diets drive large changes in the gut microbiome; however, the literature is conflicted with regard to the effect of diet on CDI. Using the hypervirulent strain C. difficile R20291 (RT027) in a mouse model of antibiotic-induced CDI, we assessed disease outcome and microbial community dynamics in mice fed two high-fat diets in comparison with a high-carbohydrate diet and a standard rodent diet. The two high-fat diets exacerbated CDI, with a high-fat/high-protein, Atkins-like diet leading to severe CDI and …

In Vitro Regeneration Of Dioscorea Alata With Anthocyanin And Antimicrobial Activity, Abdullah Sakinah

Student Works (2020-2029)

An efficient protocol was developed for rapid propagation and regeneration of the Dioscorea alata L. locally known as ‘ubi badak’ because of their rhinoceros-shaped tubers. In the present study, direct and indirect regeneration were induced to produce plantlets of Dioscorea alata L. For direct regeneration explants (leave, stem and node) were cultured on MS media supplemented with various combinations and concentrations of BAP and NAA to induce microshoots and roots formation. The optimum medium for microshoots formation was MS medium supplemented with 1.0 mg/l BAP and 0.5 mg/l NAA with the number of microshoot is 23.07±0.44 from node explant. While …

Neurodevelopment Outcome Of Neonates Treated With Intraventricular Colistin For Ventriculitis Caused By Multiple Drug-Resistant Pathogens-A Case Series, Kashif Hussain, Muhammad Sohail Salat, Gul Ambreen, Javaid Iqbal

Department of Biological & Biomedical Sciences

Background: Multiple-drug-resistant Gram-negative bacteria (MDR-GNB)-associated neonatal ventriculitis is a life-threatening complication that needs timely diagnosis and effective treatment with broad-spectrum antimicrobials in critical-care settings. Inadequate penetration of antibiotics through the blood-brain barrier also demands an intraventricular (IVT) route of administration. This study reports mortality and neurodevelopmental sequelae of neonates till 18 months of age, who received IVT-colistin for treating MDR-GNB associated ventriculitis.
Methods: In a case series of seven neonates with ventriculitis due to MDR-GNB at NICU of Aga Khan University Hospital, Pakistan, between June 2015 and 2018, we reviewed IVT-colistin therapy in critically ill neonates. Treatment outcomes were assessed …

Crispr-Cas9 Editing Of Nitrate Transporter Gene, Um03849, In Ustilago Maydis, Luke A. Schroeder, Sunita Khanal, Michael H. Perlin

Undergraduate Arts and Research Showcase

Ustilago maydis, the basidiomycete smut-fungus, can infect and cause tumors in corn plants. For this, mating between compatible haploid cells is important. The mating and subsequent dimorphic transition in U. maydis require starvation for nutrients such as nitrogen, in addition to pheromone-receptor interactions between compatible partners. In this research, the CRISPR-Cas9 gene-editing technique was used to create INDEL mutations (sequence insertion or deletion) in the nitrate transporter gene, um03849, in U. maydis. The gene was edited in mating compatible haploid strains 1/2 and 2/9. The phenotypes were characterized for the um03849 mutants as to growth ability, mating …

The Effects Of Nutrient Availability On Pseudomonas Aeruginosa Mono And Co-Culture Biofilms, Julie T. Nguyen, Deborah R. Yoder-Himes Ph.D., Rhiannon Cecil

Undergraduate Arts and Research Showcase

Cystic Fibrosis (CF) is a genetic disorder characterized by faulty ion channels and result in thick mucus accumulation, especially in lungs. Mucus buildup provides ideal conditions for bacterial infections. Pseudomonas aeruginosa (PA) is the second most prevalent bacterium isolated from people with CF and has a high clinical importance. Most CF pathogens form biofilms which make treatment of infections difficult. Biofilms are clusters of cells attached to a surface enclosed in a structured matrix. These structures are a means to provide shelter for bacteria from the environment, especially antibiotics and the immune system. PA alone can form these biofilms, but …

Biofilm Associated Staphylococcus Aureus Viability Is Altered By Burkholderia Cenocepacia, Bridget Wall, Tiffany J. Brandt, Dr. Deborah Yoder-Himes

Undergraduate Arts and Research Showcase

Respiratory failure caused by chronic and recurrent microbial infections is the most common cause of death for people with cystic fibrosis (CF)¹, a disease causing the formation of thick mucus in the lungs². Most bacteria can form biofilms, collections of sessile cells adhered to a surface by a secreted substance. Biofilm-associated cells develop antibiotic resistance at higher rates³. The thicker mucus in CF lungs is extremely difficult to clear via action of the mucociliary escalator and its presence fosters the formation of bacterial biofilms. Staphylococcus aureus and Burkholderia cenocepacia are two pathogens commonly found …

The Effects Of The Estrus Cycle On Microbiota Composition And The Opportunistic Pathogen Listeria Monocytogenes Infection Process In Murine Models, Ryan William-Thomas Donkin

Online Theses and Dissertations

In the U.S., Listeria monocytogenes accounts for less than one percent of foodborne illnesses but has a 28% mortality rate. Infection in healthy individuals causes colonization of the intestinal lumen and subclinical noninvasive listeriosis. However, translocation of L. monocytogenes across the intestinal epithelium produces invasive systemic listeriosis with central nervous system involvement. Little is known of the gastrointestinal stages of L. monocytogenes pathogenesis. Enteric pathogens such as L. monocytogenes interact directly with the host-microbiota during the gastrointestinal phase of pathogenesis. Recent research has recognized that microbiota plays a role in activating immune response and protecting against invasive pathogens. Individual host …

Mass Spectrometry Based Lipidomic Investigation Of Staphylococcus Aureus Lipid Metabolism And Characterization Of Lipase A, Naren Gajenthra Kumar

Theses and Dissertations

Staphylococcus aureus produces an arsenal of virulence factors and is adept at colonizing multiple hosts by employing specific processes to persist at different sites of infection. Infections caused by this pathogen range from self-limiting infections of the skin like folliculitis to life threatening and chronic conditions like infective endocarditis, non-healing diabetic foot ulcers and atopic dermatitis. As the field continues to expand its understanding of the mechanisms by which this pathogen rapidly develops resistance to new antibiotics, the underlying mechanisms that facilitates niche adaptation and host colonization among healthy individuals remain elusive.

Bacterial and host lipid metabolism presents and area …

The Role Of Manganese In Streptococcus Sanguinis, Tanya M. Puccio

Theses and Dissertations

Streptococcus sanguinis is primarily associated with oral health as a commensal bacterium. As an opportunistic pathogen, S. sanguinis is capable of colonizing heart valve vegetations, leading to the disease infective endocarditis. Previous studies from our lab have identified the high-affinity manganese transporter SsaACB as important for endocarditis virulence. The impact that manganese depletion has on S. sanguinis had never been evaluated and a secondary manganese transporter has not been identified. Thus, we employed the use of a fermentor to control large-scale growth over time and depleted manganese in an ΔssaACB mutant using a metal chelator, EDTA. The changes in …

Genomic And Culturomic Analysis Of Gut Microbiota Function And Salmonella Enterica Expansion, Gavin Fenske

Electronic Theses and Dissertations

Enteric bacteria that are resident in the hindgut of mammals are critical in immune development, digestion, and colonization resistance against pathogens. One of the major pathogens that gut commensals provide resistance against is Salmonella enterica, a major foodborne pathogen capable of infecting almost every warm-blooded animal. Given the interplay between pathogens and commensals in the gut lumen, the gut microbiota of pigs was studied by combining two disparate techniques: shotgun metagenomics and high throughput culturomics. Metagenomics readily identifies major taxa present in samples and can give an estimation to total genetic catalogue from an environment. However, many rare or …

Tick-Borne Infections In New Hampshire: An Evaluation Of The Diagnostic Process In A Local Patient Population, Katherine Anderson

Honors Theses and Capstones

Overall, approximately 95 percent of reported cases of vector-borne disease were associated with ticks, making these the most medically important group of arthropods in the United States.¹ Despite the prevalence of tick-borne infections, the process for the diagnosis of this condition is not well studied. This study aims to analyze data from a pool of 100 patients who underwent testing for tick-borne disease in the same institution in Dover, New Hampshire during the most recent peak tick season of 2019. Information utilized in this study included: patient age, sex, location of testing (inpatient versus outpatient), diagnostic testing methods used …

Molecular Facet Of Host-Pathogen Interactions In Fusarium Head Blight In Wheat ( Triticum Aestivum L.), Bimal Paudel

Electronic Theses and Dissertations

Fusarium head blight (FHB) is a severe disease of wheat (Triticum aestivum L.). It not only reduces the quantity of the harvested grains but also decreases the grain quality due to mycotoxins contamination, especially Deoxynivalenol (DON). Qfhb1 (or simply called Fhb1) is the most important quantitative trait locus (QTL) for FHB resistance. Our lab has previously identified wheat gene WFhb1-1 (aka. Wfhb1_c1) as a candidate for FHB resistance gene. Here we report that WFhb1-1 has been cloned. The gene (GenBank # KU304333.1) consists of a single exon, encoding a putative membrane protein of 127 amino acids. WFhb1-1 protein produced in …

Impact Of Chytrid Fungus Pathogen On The Skin Microbiome Of Frogs In Northern Idaho And Turnbull National Wildlife Refuge, Washington, Philip M. Campos

EWU Masters Thesis Collection

Amphibians worldwide are under threat from the infectious disease chytridiomycosis, which is caused by the chytrid fungus Batrachochytrium dendrobatidis (Bd). Bd is associated with the population declines of an estimated 501 species, 90 of which are presumed or confirmed extinct, making this the greatest documented loss of biodiversity attributed to a disease. Researching the amphibian skin microbiome may provide solutions to conservation of amphibians. Two main relationships have been observed between Bd and the microbiome: 1) bacteria producing antifungal metabolites can inhibit Bd and improve survival against the disease and 2) infection by Bd is believed to affect the composition …