Bacterial Infections and Mycoses Commons^™

Contributions Of Gyra And Parc Mutations And Qnrs2 Acquisition To Ciprofloxacin Resistance In Aeromonas Veronii Hm21, Daniel J. Silverstein

Honors Scholar Theses

In recent years, ciprofloxacin resistant (CpR) Aeromonas veronii and A. hydrophila strains have been isolated from the wounds of patients receiving leech therapy. Genome comparisons of these CpR isolates revealed the presence of chromosomal mutations in gyrA and parC as well as the gain of qnrS2 on either a large, 34 kb, conjugatable, low-copy plasmid, pAv42, or on a small, 6.8 kb, high-copy plasmid, pAh1471. The minimum inhibitory concentration, MIC, for Cp of these clinical isolates ranged from 1 to ≥32 µg/mL and some harbored a qnrS2 containing plasmid. We wanted to assess the contributions of these factors in an …

Gut Pathophysiology In Mouse Models Of Social Behavior Deficits, Kyla Scott

Undergraduate Honors Theses

Autism spectrum disorders (ASD) encompass neurodevelopment disorders characterized by atypical patterns of development that impact multiple areas of functioning beginning in early childhood. The etiology of ASD is unknown and there are currently no preventative treatment options. Gastrointestinal symptoms are commonly associated comorbidities. The microbiota-gut-brain axis is a multidirectional communication chain that connects the central and enteric nervous system that relates brain function to peripheral intestinal functions. Changes within this axis have been postulated in ASD. For example, the “leaky gut theory” proposes that chronic inflammation is linked to alterations in the bacterial profiles of the gut microbiome and subsequent …

Molecular Mechanisms Of Antimicrobial Resistance In Multi-Drug Resistant Enterococci, Ayesha Khan

Dissertations and Theses (Open Access)

Antibiotic resistance is a major global public health threat. Enterococci are recalcitrant, nosocomial pathogens that can be intrinsically resistant to valuable antibiotics, like beta-lactams, or evolve resistance to all existing antimicrobials. The LiaFSR system regulates resistance to cell membrane (CM) stressors like daptomycin (DAP), a front-line drug for multi-drug resistant infections. DAP resistance (DAP-R) in E. faecalis is mediated by CM phospholipid alterations. Emergence of DAP-R often leads to b-lactam resensitization, a phenomenon called the seesaw effect. The molecular mechanism of DAP-R and the seesaw effect are unknown. Here we show that LiaX is a surface exposed protein whose C-terminal …

The Effects Of Farnesol, A Quorum Sensing Molecule From Candida Albicans, On Alcaligenes Faecalis, Savannah Hutson

Undergraduate Honors Theses

Quorum sensing molecules have become a recent focus of study to learn if and how they can be used, both on their own and in conjecture with current antimicrobial methods, as a means of bacterial control. One such quorum sensing molecule is the sesquiterpene alcohol, Farnesol, which is synthesized and released by the fungus, Candida albicans. In most in-vivo cases, our laboratory has shown that Alcaligenes faecalis overtakes C. albicans, preventing its growth. However, as a way to counteract this inhibitory effect, Farnesol may be one way that Candida has found to fight back. In this study, we …

Non-Tuberculous Mycobacterial Infections-A Neglected And Emerging Problem, Imran Ahmed, Simon Tiberi, Joveria Farooqi, Kauser Jabeen, Dorothy Yeboah-Manu, Giovanni Battista Migliori, Rumina Hasan

Department of Pathology and Laboratory Medicine

Non-tuberculous mycobacteria (NTM) are ubiquitous dwellers of environmental niches and are an established cause of natural and nosocomial infections. The incidence of NTM infections is rising owing to a growing population of immunocompromised and vulnerable individuals, complex medical and surgical procedures, as well as increased awareness and diagnostic capabilities. The prevalence of different NTM varies between continents, regions, and countries. The true global burden of pulmonary and extrapulmonary disease is unknown and estimates are subject to under and/or over-estimation. Diagnosis requires confirmation by isolation of NTM along with clinical and radiological criteria, which may be suboptimal at all levels. Susceptibility …

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 …

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 …

Antibacterial, Antifungal, Antioxidant Activity And Polyphenol Content Of Aerial Parts And Bulbs Of Allium Schugnanicum., Saidbeg Satorov, F. Mirzoeva, Sh. Kurbonbekova, Sh. Satorov, M. Vakhidova, Vyacheslav Dushenkov

Publications and Research

Objective: То study of antibacterial, antifungal and antioxidant activity, and content of polyphenols in the bulb and aerial parts of an endemic species of onion A. schugnanicum. Methods: An ethanol-based extract was prepared from fresh plants. Total polyphenolic content (Folin) and ABTS antioxidant capacity assays were used to characterized extracts. Extracts obtained from bulbs, peduncle, and seeds demonstrated antibacterial activity against the reference Staphylococcus aureus (ATCC 4929), Pseudomonas aeruginosa (ATCC 4930) and Klebsiella pneumoniae (ATCC 4927) strains, as well as against the hospital strains of the same types of bacteria, i.e. strains isolated from inpatient surgical patients. Results: The study …

Incidence And Prevalence Of Francisella Noatunensis Subsp. Orientalis (Fno) Pathogenic Infections In Feral Hawaiian Tilapia, Daquille Peppers

Biology Theses

Aquaculture has become a major food source for many countries and continues to grow each year. However, many of the fishes that are farmed are susceptible to pathogenic infections such as Francisellosis, a bacterial infection that contributes to disease and high mortality rate in many populations of farmed and wild fish around the world. In 1994, feral and farmed populations of tilapia (e.g. Oreochromis mossambicus) on Oahu, Hawaii were found to be infected with a novel Francisellosis strain, Francisella noatunensis subsp. orientalis (Fno). To prevent the spread of this pathogen, the Hawaii Department of Aquaculture (HDOA) initiated …

Elucidating Immune Signaling Of Influenza A Virus And Aspergillus Fumigatus Co-Infections Through Pioneered Model Development, Meagan Danyelle Rippee-Brooks

Graduate Theses/Dissertations

Bacterial co-infections with influenza A virus (IAV) are extremely serious and life-threatening. However, there exists limited understanding about the importance of fungal infections with IAV. Clinical case reports indicate that fungal co-infections do occur and suggest the IAV pandemic of 2009 had a propensity to predispose patients to secondary fungal infections more than previous IAV strains. IAV-fungal co-infections are marked by high mortality rates of 47 to 61% in previously healthy individuals between the ages of 20 and 60. Yet, the variables involved in this co-infection remain undetermined. I achieved effective recapitulation of this co-infection using a C57Bl/6 murine (mouse) …

Modeling Disease Impact Of Vibrio-Phage Interactions, Christopher Botelho

Electronic Theses and Dissertations

Since the work of John Snow, scientists and medical professionals have understood that individuals develop cholera by means of consuming contaminated water. Despite the knowledge of cholera's route of infection, many countries have experienced and still experience endemic cholera. Cholera is caused by the Vibrio cholerae (V. cholerae) bacterium and presents with acute diarrhea and vomiting. If untreated, infected individuals may die due to dehydration. Cholera is a disease that most commonly affects countries with poor infrastructure and water sanitation. Despite efforts to control cholera in such countries, the disease persists. One such example is Haiti which has been experiencing …

Adaptation Of The Streptococcal Collagen-Like Protein 1, Scl1, Of Group A Streptococcus To Recognize Fibronectin Type Iii Repeats, Dudley H. Mcnitt

Graduate Theses, Dissertations, and Problem Reports (ETD)

Background: Group A Streptococcus (GAS) is responsible more than 700 million infections worldwide each year. Most of these infections start with initial colonization of the throat and skin, which is augmented by surface adhesins. The streptococcal collagen-like protein 1 (Scl1) is a major adhesin expressed by GAS that contains an N-terminal sequence-variable (V) domain, protruded away from the cell surface by the collagen domain. The Scl-V domain is comprised of three pairs of anti-parallel α-helices interconnected by surface-exposed loops. For attachment, GAS adhesins require a portal of entry, such as a wound or breach in the epithelium, to enter …

Investigation Of Novel Virulence Mechanisms In Candida Albicans, Elisa Marie Tafoya Vesely

Dissertations and Theses (Open Access)

Candida albicans is the most important fungal species associated with humans. Normally present in the human microbiome as a commensal colonizer, C. albicans is also the fourth most prevalent organism isolated from bloodstream infections in hospitals. Disseminated infections have an associated mortality rate of around 40%. The results of the work described in this dissertation cover the broad subject of C. albicans adaptation to the host and the mechanisms by which this organism is able to survive and cause infection through a variety of means. A key determinant in disease progression is interaction with innate immune cells, specifically macrophages and …

Simulating Antibiotic Resistance In The Computer Lab And Biology Lab: Ideas For Undergraduate Projects, Anne E. Yust

Annual Symposium on Biomathematics and Ecology Education and Research

No abstract provided.

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 …

Nutritional Virulence Of Legionella Pneumophila., Ashley M. Best

Electronic Theses and Dissertations

Legionella pneumophila is an environment organism that parasitizes a wide range of protozoa. Growth within the environmental host primes L. pneumophila for infection of human alveolar macrophages when contaminated aerosols are inhaled. Intracellular replication within either host requires the establishment a replicative niche, known as the Legionella-containing vacuole (LCV). Biogenesis of the LCV depends on the type IVb translocation system, the Dot/Icm, to translocation >320 effectors into the host cytosol. Effectors are responsible for preventing lysosome fusion to the LCV, recruitment of ER-derived vesicles to the LCV, and modulation of a plethora of host processes to promote the intracellular …

Bioprospecting Deep-Sea Actinobacteria For Novel Anti-Infective Natural Products, Dongbo Xu, Linna Han, Chunhui Li, Qi Cao, Duolong Zhu, Nolan H. Barrett, Dedra Harmody, Jing Chen, Haining Zhu, Peter J. Mccarthy, Xingmin Sun, Guojun Wang

Molecular and Cellular Biochemistry Faculty Publications

The global prevalence of drug resistance has created an urgent need for the discovery of novel anti-infective drugs. The major source of antibiotics in current clinical practice is terrestrial actinobacteria; the less-exploited deep-sea actinobacteria may serve as an unprecedented source of novel natural products. In this study, we evaluated 50 actinobacteria strains derived from diverse deep water sponges and environmental niches for their anti-microbial activities against a panel of pathogens including Candida albicans, Clostridium difficile, Staphylococcus aureus, and methicillin-resistant S. aureus (MRSA), and Pseudomonas aeruginosa. More than half of the tested strains (27) were identified as …

In Vitro Assay Development As An Alternative To The Use Of Laboratory Animals For Measuring Clostridium Perfingens Type C Toxoid, Lauren M. Wilmes

School of Veterinary and Biomedical Sciences: Dissertations, Theses, and Student Research

Clostridium perfringens type C produces beta toxin, which is a primary virulence determinate that can cause necrotic enteritis in neonatal animals. Vaccines directed against C. perfringens toxins have shown to be efficacious in preventing disease. However, the production of a commercial vaccine requires not only an efficacious antigen, but also testing methods for quantifying antigens and potency on final product. This research was undertaken to fulfill a need for the reduction in small animal usage to produce and deliver vaccines. The current testing methods are performed in vivo according to the Code of Federal Regulations number 9 (9CFR) United …

Rapid Identification And Typing Of Mycobacterium Avium Complex Using Matrix Assisted Laser Desorption/Ionization Time-Of-Flight Mass Spectrometry (Maldi-Tof) Library And Biomarker Based Approaches, Claudia Antonika, John Dustin Loy, Raul Barletta, Michael Collins

UCARE: Research Products

Bacteria associated with the Mycobacterium avium complex (MAC) cause significant problems in animal agriculture and cause large economic losses and morbidity of livestock. Two clinically important subspecies of M. avium are M.avium ssp paratuberculosis (MAP) and M. avium ssp hominissuis (MAH). MAP is the etiologic agent of Johne’s disease, a chronic and fatal enteritis in ruminants, that has been linked to Crohn’s disease in humans.1 MAH has zoonotic potential as it is one of the leading causes of secondary infections in AIDS patients. Identification of M. avium in clinical samples is challenging as they have overlapping host ranges and clinical …

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 …

Discovery Of New Antimicrobial Options And Evaluation Of Aminoglycoside Resistance Enzyme-Associated Resistance Epidemic, Selina Y. L. Holbrook

Theses and Dissertations--Pharmacy

The extensive and sometimes incorrect and noncompliant use of various types of antimicrobial agents has accelerated the development of antimicrobial resistance (AMR). In fact, AMR has become one of the greatest global threat to human health in this era. The broad-spectrum antibiotics aminoglycosides (AGs) display excellent potency against most Gram-negative bacteria, mycobacteria, and some Gram-positive bacteria, such as Staphylococcus aureus. The AG antibiotics amikacin, gentamicin, kanamycin, and tobramycin are still commonly prescribed in the U.S.A. for the treatment of serious infections. Unfortunately, bacteria evolve to acquire resistance to AGs via four different mechanisms: i) changing in membrane permeability to …

Phytochemical Screening And Determination Of Antibacterial, Anti-Tumorigenic And Dna Protection Ability Of Root Extracts Of Saussurea Lappa, Sughra Arif Minhas, Fida Muhammad Khan, Fakhar-I- Abbas, Abu Ul Hassan Faiz

Journal of Bioresource Management

Saussurea lappa is a traditionally well-known plant for its medicinal uses in different indigenous systems of medicine. It is widely used in the treatment of asthma, ulcer, stomach problems and inflammatory diseases. In current study the phytochemical screening of S. lappa showed the presence of sesquiterpenes, anthraquinones, lignans, alkaloids, flavonoids, glycosides and steroids. Antimicrobial potential of subject plant was also investigated against three bacterial strains and maximum antibacterial activity was observed by CEE against S. aureus, CAE against P. aeruginosa, while CME, CEE, EAE and PEE showed almost same significant activity against E. coli. The CME (1000 …

Characterization Of Different Molecular Markers For Identification Of Salmonella Enterica Serovar Typhi In Pakistani Population, Faizan Muttiullah, Fida Muhammad Khan, Fakhar-I- Abbas, Sabiha Shamim

Journal of Bioresource Management

Typhoid is caused by Salmonella enterica serovar Typhi that is usually diagnosed by using serologic and immuno-chromatographic techniques in developing counties including Pakistan, which is thought to be an unreliable diagnostic method. For accurate diagnosis we used molecular techniques to amplify 204 bp StyR-36 and 498 bp flagellin gene for the identification of Salmonella enterica serovar Typhi. This study was done on 58 individuals diagnosed positive of typhoid via serologic tests and 50 healthy individuals as a control group. Success rate of amplification for flagellin gene was 77.58% while that for StyR-36 gene was 68.97% showing that flagellin gene primer …

The Feoabc Locus Of Yersinia Pestis Likely Has Two Promoters Causing Unique Iron Regulation, Lauren O'Connor, Jacqueline D. Fetherston, Robert D. Perry

Microbiology, Immunology, and Molecular Genetics Faculty Publications

The FeoABC ferrous transporter is a wide-spread bacterial system. While the feoABC locus is regulated by a number of factors in the bacteria studied, we have previously found that regulation of feoABC in Yersinia pestis appears to be unique. None of the non-iron responsive transcriptional regulators that control expression of feoABC in other bacteria do so in Y. pestis. Another unique factor is the iron and Fur regulation of the Y. pestis feoABC locus occurs during microaerobic but not aerobic growth. Here we show that this unique iron-regulation is not due to a unique aspect of the Y. pestis …

Colonization Density Of The Upper Respiratory Tract As A Predictor Of Pneumonia-Haemophilus Influenzae, Moraxella Catarrhalis, Staphylococcus Aureus, And Pneumocystis Jirovecii., Daniel E Park, Henry C Baggett, Stephen R C Howie, Qiyuan Shi, Nora L Watson, W Abdullah Brooks, Perch Study Group

Epidemiology Faculty Publications

Background.

There is limited information on the association between colonization density of upper respiratory tract colonizers and pathogen-specific pneumonia. We assessed this association for Haemophilus influenzae, Moraxella catarrhalis, Staphylococcus aureus, and Pneumocystis jirovecii. Methods.

In 7 low- and middle-income countries, nasopharyngeal/oropharyngeal swabs from children with severe pneumonia and age-frequency matched community controls were tested using quantitative polymerase chain reaction (PCR). Differences in median colonization density were evaluated using the Wilcoxon rank-sum test. Density cutoffs were determined using receiver operating characteristic curves. Cases with a pathogen identified from lung aspirate culture or PCR, pleural fluid culture or …

Lymphoid Hematopoiesis And The Role Of B-Cells In Transgenic Mouse Model Of Sickle Cell Disease, Christina Cotte

University Scholar Projects

Sickle cell disease (SCD) has been shown to be associated with decreased baseline immunity and thus increased susceptibility to infection. I sought to discern possible causes of this by looking into the correlations between SCD and hematopoiesis, the immune system and the neuroendocrine system, and ultimately by conducting experiments surrounding the impaired immune system of SCD. These experiments focused on the potential causes and effects of the diminution of B-1a cells in the SCD spleen. Adoptive transfers, infections with Streptococcus pneumoniae, and histologic imaging were conducted to establish if the diminution of the B-1a cells in the SCD spleen …

Molecular Subtyping Of Staphylococcus Aureus Isolates From The U.P. Community For The Presence Of Toxin-Encoding Genes, Carol I. Kessel

All NMU Master's Theses

Staphylococcus aureus is the most common cause of human bacterial infections; however, humans can also be asymptomatically colonized with S. aureus. Asymptomatic carriers can potentially spread S. aureus infection to others. These infections can range from mild to severe. The pathology of a S. aureus infection is often dependent on which toxins are expressed and the virulence factors with which they are associated. One goal of this study was to isolate S. aureus from healthy, consenting adult volunteers who submitted nasal swabs for culture and qRT-PCR analysis to determine which strains are present in the community. This knowledge could …

Study Of Rickettsia Parkeri Colonization And Proliferation In The Tick Host Amblyomma Maculatum (Acari: Ixodidae), Khemraj Budachetri

Dissertations

Amblyomma maculatum (Gulf coast tick) ticks are prevalent across the Atlantic to Gulf Coast region of United States. These ticks are recognized vectors of Rickettsia parkeri, a spotted fever group of Rickettsia (SFGR) known to cause American boutonneuse fever associated with fever and eschar rashes localized to the site of bites. We hypothesized that Rickettsia parkeri colonization and proliferation in the tick vector involve pathogen-symbiont dynamics and tick-pathogen interactions, which influence rickettsial transmission to the victims after tick bites. The rickettsial infection is maintained across the tick life cycle for many generations due to transovarial and transstadial transmission of …

Pulmonary Surfactant Fortified With Cath-2 As A Novel Therapy For Bacterial Pneumonia, Brandon J. Baer

Western Research Forum

Background: Bacterial pneumonia is a leading cause of death worldwide, with high mortality rates persisting even after antibiotic treatment. Current treatments for pneumonia involve administration of antibiotics, however after the bacteria are killed they release toxic substances that induce inflammation and lung dysfunction. Host defense peptides represent a potential solution to this problem through their ability to down regulate inflammation. However, effective delivery to the lung is difficult because of the complex branching structure of the airways. My study addresses this delivery problem by using exogenous surfactant, a pulmonary delivery vehicle capable of improving spreading of these peptides throughout the …

Enhanced Control Of Mycobacterium Tuberculosis Extrapulmonary Dissemination In Mice By An Arabinomannan-Protein Conjugate Vaccine, R Prados-Rosales, L Carreno, T Cheng, C Blanc, B Weinrick, Aharona Glatman-Freedman, A Casadevall, S Hung, A Tripathi, J Xu, Aharona Glatman-Freedman, W Jacobs Jr., J Chan, S Porcelli, J Achkar, A Casadevall

NYMC Faculty Publications

Currently there are a dozen or so of new vaccine candidates in clinical trials for prevention of tuberculosis (TB) and each formulation attempts to elicit protection by enhancement of cell-mediated immunity (CMI). In contrast, most approved vaccines against other bacterial pathogens are believed to mediate protection by eliciting antibody responses. However, it has been difficult to apply this formula to TB because of the difficulty in reliably eliciting protective antibodies. Here, we developed capsular polysaccharide conjugates by linking mycobacterial capsular arabinomannan (AM) to either Mtb Ag85b or B. anthracis protective antigen (PA). Further, we studied their immunogenicity by ELISA and …