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Pathogenic Microbiology Commons

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2015

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Articles 31 - 50 of 50

Full-Text Articles in Pathogenic Microbiology

Characterization Of The Poxab Operon Encoding A Class D Carbapenemase In Pseudomonas Aeruginosa,, Diansy Zincke Mar 2015

Characterization Of The Poxab Operon Encoding A Class D Carbapenemase In Pseudomonas Aeruginosa,, Diansy Zincke

FIU Electronic Theses and Dissertations

Pseudomonas aeruginosa is a dreaded opportunistic pathogen that causes severe and often intractable infections in immunocompromised and critically ill patients. This bacterium is also the primary cause of fatal lung infections in patients with cystic fibrosis and a leading nosocomial pathogen responsible for nearly 10% of all hospital-acquired infections. P. aeruginosa is intrinsically recalcitrant to most classes of antibiotics and has the ability to acquire additional resistance during treatment. In particular, resistance to the widely used β-lactam antibiotics is frequently mediated by the expression of AmpC, a chromosomally encoded β-lactamase that is ubiquitously found in P. aeruginosa strains. This dissertation ...


Chitin Recognition Via Chitotriosidase Promotes Pathologic Type-2 Helper T Cell Responses To Cryptococcal Infection, Darin L. Wiesner, Charles A. Specht, Chrono K. Lee, Kyle D. Smith, Liliane Mukaremera, S. Thera Lee, Chun G. Lee, Jack A. Elias, Judith N. Nielsen, David R. Boulware, Paul R. Bohjanen, Marc K. Jenkins, Stuart M. Levitz, Kirsten Nielsen Mar 2015

Chitin Recognition Via Chitotriosidase Promotes Pathologic Type-2 Helper T Cell Responses To Cryptococcal Infection, Darin L. Wiesner, Charles A. Specht, Chrono K. Lee, Kyle D. Smith, Liliane Mukaremera, S. Thera Lee, Chun G. Lee, Jack A. Elias, Judith N. Nielsen, David R. Boulware, Paul R. Bohjanen, Marc K. Jenkins, Stuart M. Levitz, Kirsten Nielsen

Open Access Articles

Pulmonary mycoses are often associated with type-2 helper T (Th2) cell responses. However, mechanisms of Th2 cell accumulation are multifactorial and incompletely known. To investigate Th2 cell responses to pulmonary fungal infection, we developed a peptide-MHCII tetramer to track antigen-specific CD4+ T cells produced in response to infection with the fungal pathogen Cryptococcus neoformans. We noted massive accruement of pathologic cryptococcal antigen-specific Th2 cells in the lungs following infection that was coordinated by lung-resident CD11b+ IRF4-dependent conventional dendritic cells. Other researchers have demonstrated that this dendritic cell subset is also capable of priming protective Th17 cell responses to another pulmonary ...


Concomitant Uptake Of Antimicrobials And Salmonella In Soil And Into Lettuce Following Wastewater Irrigation, J. Brett Sallach, Yuping Zhang, Laurie Hodges, Daniel D. Snow, Xu Li, Shannon L. Bartelt-Hunt Feb 2015

Concomitant Uptake Of Antimicrobials And Salmonella In Soil And Into Lettuce Following Wastewater Irrigation, J. Brett Sallach, Yuping Zhang, Laurie Hodges, Daniel D. Snow, Xu Li, Shannon L. Bartelt-Hunt

Civil Engineering Faculty Publications

The use of wastewater for irrigation may introduce antimicrobials and human pathogens into the food supply through vegetative uptake. The objective of this study was to investigate the uptake of three antimicrobials and Salmonella in two lettuce cultivars. After repeated subirrigation with synthetic wastewater, lettuce leaves and soil were collected at three sequential harvests. The internalization frequency of Salmonella in lettuce was low. A soil horizon-influenced Salmonella concentration gradient was determined with concentrations in bottom soil 2 log CFU/g higher than in top soil. Lincomycin and sulfamethoxazole were recovered from lettuce leaves at concentrations as high as 822 ng ...


The Shellfish Corner--Shellfish Sanitation And The Price Of Shellfish, Michael A. Rice Jan 2015

The Shellfish Corner--Shellfish Sanitation And The Price Of Shellfish, Michael A. Rice

Michael A Rice

Prices of raw molluscan shellfish in different countries around the world are tied to perceived risk of becoming ill if consumed. Wholesale prices of oysters in the southern New England from 1880 to 2010 are analyzed in relation to introduction of flush toilets and sewer systems in the early 20th Century, the initiation of the US National Shellfish Sanitation Program in 1925 and renewed consumer interest in consuming raw shellfish in the latter half of the 20th Century.


The Frequency Of Ticks Carrying Rickettsia Sp., Sarah C. Canterberry, Daniel J. Bennett, Robert J. Wiggers Jan 2015

The Frequency Of Ticks Carrying Rickettsia Sp., Sarah C. Canterberry, Daniel J. Bennett, Robert J. Wiggers

Faculty Publications

No abstract provided.


Strain Typing Mycobacterium Marinum From Outbreaks At Zebrafish Research Facilities, Brooke M. Clemons Jan 2015

Strain Typing Mycobacterium Marinum From Outbreaks At Zebrafish Research Facilities, Brooke M. Clemons

Honors Theses

Zebrafish (Danio rerio) are used as model organisms for biological research due to their rapid and transparent development and high fecundity amongst other reasons. Research has expanded beyond embryonic studies, with adult fish used for longer-term studies such as human disease and senescence. Zebrafish are often housed at high density in large colonies. As with any similar husbandry situation, diseases can occur, with impacts that range from morbidity to premature mortality costing researchers time and money. Understanding the impact of underlying diseases in zebrafish is crucial, particularly for long-term studies where chronic infections may confound results. One such disease problem ...


Dark Spots Disease Increase In Scleractinian Corals In Bonaire, D.C., Jennifer Mathe Jan 2015

Dark Spots Disease Increase In Scleractinian Corals In Bonaire, D.C., Jennifer Mathe

Honors Theses

Pathogen-host relation dynamics have adjusted in the Caribbean due to increased epizootic events and decreased coral cover resulting from anthropogenic influences. Reef-building corals are being infected by numerous diseases including dark spots disease, a ubiquitous Caribbean disease of an unknown agent. The objectives of this study were to quantify the change in dark spots disease prevalence in Siderastrea siderea and Stephanocoenia spp. from 1998 to 2014 and determine influencing conditions on prevalence and infection severity of disease. The abundance of benthic organisms and substrate types were also quantified. A 1350 m2 area between six sites on Bonaire was surveyed using ...


Application Of Supervised Machine Learning Algorithms For Rapid Identification Of Mrsa Pfge Strain Types, Michael L. Bernauer Jan 2015

Application Of Supervised Machine Learning Algorithms For Rapid Identification Of Mrsa Pfge Strain Types, Michael L. Bernauer

Biomedical Informatics

Introduction: Pulsed-field gel electrophoresis (PFGE) is a molecular typing method used in epidemiologic surveillance of MRSA. PFGE relies on electrophoretic migration of restricted DNA fragments, resulting in characteristic fingerprints which can be used to classify organisms. Current methods of analysis, such as Gel Compar II and BioNumerics rely on unsupervised hierarchical clustering algorithms to group organisms based on pairwise similarity. These methods are labor intensive, often requiring a significant amount of user intervention and oversight. This study presents an automated approach to PFGE typing to reduce the amount of user involvement and time required for analysis.

Methods: A total of ...


Identification And Characterization Of Functional Regulatory Variants In S. Cerevisiae, Timothy Read Jan 2015

Identification And Characterization Of Functional Regulatory Variants In S. Cerevisiae, Timothy Read

Molecular, Cellular, and Developmental Biology Graduate Theses & Dissertations

Most genetic variants associated with disease occur within regulatory regions of the genome, underscoring the need to define the mechanisms that control differences in gene expression regulation between individuals. I discovered a pair of co-regulated, divergently oriented transcripts, AQY2 and ncFRE6, that are expressed in one strain of S.cerevisiae, ∑1278b, but not in another, S288c. By combining classical genetics techniques with high-throughput sequencing, I identified a trans-acting single nucleotide polymorphism within the transcr¬iption factor RIM101 that causes the background-dependent expression of both transcripts. Subsequent RNA-seq experiments revealed that deletion of RIM101 in both backgrounds abrogated the majority of ...


Eneterotoxigenic Bacillus Cereus And Bacillus Thuringiensis Spores In U.S. Retail Spices, Upasana Hariram Jan 2015

Eneterotoxigenic Bacillus Cereus And Bacillus Thuringiensis Spores In U.S. Retail Spices, Upasana Hariram

Masters Theses

Bacillus cereus is a ubiquitous organism and a potential foodborne pathogen that can cause two types of gastrointestinal diseases: emesis and diarrhea. The emetic syndrome is caused by a heat and acid stable peptide toxin that is pre-formed in food, while the diarrheal syndrome is associated to two 3-protein, heat labile enterotoxin complexes that are formed in the intestine after ingestion of the organism. There are many reports on the isolation and characterization of Bacillus cereus from various foods, however there are no studies on the levels, toxigenicity and physical characteristics of B. cereus isolated from U.S. retail spices ...


Characterization Of The Interactions Between Staphylococcal Phage 80 Alpha Scaffold And Capsid Proteins, Laura Klenow Jan 2015

Characterization Of The Interactions Between Staphylococcal Phage 80 Alpha Scaffold And Capsid Proteins, Laura Klenow

Theses and Dissertations

Staphylococcal phage 80α can serve as a helper bacteriophage for a family of mobile genetic elements called Staphylococcus aureus pathogenicity islands (SaPIs). The prototype island, SaPI1, is able to hijack the 80α capsid assembly process and redirect capsid formation to yield smaller, phage-like transducing particles carrying SaPI DNA. Capsid size redirection is accomplished through two SaPI1-encoded gene products, CpmA and an alternate scaffold protein, CpmB. The normal 80α scaffold and the SaPI1 CpmB scaffold share a small block of conserved residues at their C-termini, several of which had been shown to be essential for CpmB function. This led to the ...


Candida Albicans Quorum Sensing Molecules Stimulate Mouse Macrophage Migration, Jessica C. Hargarten, Tyler C. Moore, Thomas M. Petro, Kenneth W. Nickerson, Audrey L. Atkin Jan 2015

Candida Albicans Quorum Sensing Molecules Stimulate Mouse Macrophage Migration, Jessica C. Hargarten, Tyler C. Moore, Thomas M. Petro, Kenneth W. Nickerson, Audrey L. Atkin

Kenneth Nickerson Papers

The polymorphic commensal fungus Candida albicans causes life-threatening disease via bloodstream and intra-abdominal infections in immunocompromised and transplant patients. Although host immune evasion is a common strategy used by successful human fungal pathogens, C. albicans provokes recognition by host immune cells less capable of destroying it. To accomplish this, C. albicans white cells secrete a low-molecular-weight chemoattractive stimulant(s) of macrophages, a phagocyte that they are able to survive within and eventually escape from. C. albicans opaque cells do not secrete this chemoattractive stimulant( s). We report here a physiological mechanism that contributes to the differences in the interaction of ...


Proteomic Adaptations To Starvation Prepare Escherichia Coli For Disinfection Tolerance, Zhe Du, Renu Nandakumar, Kenneth W. Nickerson, Xu Li Jan 2015

Proteomic Adaptations To Starvation Prepare Escherichia Coli For Disinfection Tolerance, Zhe Du, Renu Nandakumar, Kenneth W. Nickerson, Xu Li

Kenneth Nickerson Papers

Despite the low nutrient level and constant presence of secondary disinfectants, bacterial re-growth still occurs in drinking water distribution systems. The molecular mechanisms that starved bacteria use to survive low-level chlorine-based disinfectants are not well understood. The objective of this study is to investigate these molecular mechanisms at the protein level that prepare starved cells for disinfection tolerance. Two commonly used secondary disinfectants chlorine and monochloramine, both at 1 mg/L, were used in this study. The proteomes of normal and starved Escherichia coli (K12 MG1655) cells were studied using quantitative proteomics. Over 60-min disinfection, starved cells showed significantly higher ...


Letter From The Dean, Michael Vayda Jan 2015

Letter From The Dean, Michael Vayda

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

No abstract provided.


Alternate Germinants Of C. Difficile, A Leading Hospital Pathogen, Sean Tanzey, Ernesto Abel-Santos Jan 2015

Alternate Germinants Of C. Difficile, A Leading Hospital Pathogen, Sean Tanzey, Ernesto Abel-Santos

McNair Poster Presentations

Clostridium difficile infections (CDI) are the leading nosocomial infections worldwide. Humans are asymptomatic carriers of C. difficile spores in the intestinal tract. The process known as germination occurs when otherwise harmless C. difficile spores are converted to toxin-producing cells upon recognition of bile salts in humans. This distinctive transition ultimately leads to the onset of disease and recurrent CDI. Germination profiles will be characterized in response to peptidoglycan (PG) fragments isolated from various bacterial species. These specific peptidoglycan fragments contain different amino acid residues that may induce different germination responses. Purification and structural determination of the peptidoglycan fragments will be ...


Purification And Characterization Of Bcsc; An Integral Component Of Bacterial Cellulose Export, Emily D. Wilson Ms Jan 2015

Purification And Characterization Of Bcsc; An Integral Component Of Bacterial Cellulose Export, Emily D. Wilson Ms

Theses and Dissertations (Comprehensive)

Biofilms are a growing concern in the medical field due to their increased resistance to antibiotics. When found in a biofilm, bacteria can have antibiotic resistance 10-1000 times that of their planktonic counterparts. Therefore, it is important to study the formation of biofilms. Cellulose biofilms are formed by Enterobacteriaceae, such as many Escherichia coli and Salmonella spp. strains. Biofilms provide these species with benefits including antimicrobial protection, development of bacterial communities, promotion of DNA exchange, uptake of nutrients, and, in the case of cellulose biofilms, immune system evasion. Cellulose biofilms are controlled by the Bacterial cellulose synthesis (Bcs) complex located ...


Antimicrobial Efficacy Of Natural Bioactive Compounds And High Pressure Processing Against Potential Pathogens In Infant Foods, Hayriye Cetin-Karaca Jan 2015

Antimicrobial Efficacy Of Natural Bioactive Compounds And High Pressure Processing Against Potential Pathogens In Infant Foods, Hayriye Cetin-Karaca

Theses and Dissertations--Animal and Food Sciences

This study investigated the antimicrobial efficacy of bioactive plant compounds along with high pressure processing (HPP) against pathogens Bacillus cereus and Cronobacter sakazakii in infant formula and infant rice cereal. The influence of these applications on antimicrobial activity, shelf-life and sensory attributes of infant foods were examined.

Trans-cinnamaldehyde (TC), (-)-Epigallocatechin gallate (EGCG) and [10]-Gingerol (GI) were incorporated (0.05%) in infant rice cereal reconstituted with infant formula. The cereal was inoculated with either B. cereus (ATCC 14579) or B. cereus spores (107-108 log CFU g-1). All the samples were stored at 7, 23 or 37 ...


The Effect Of Antibiotics On Pseudomonas Aeruginosa Biofilm Production, Courtney Paige Turpin Jan 2015

The Effect Of Antibiotics On Pseudomonas Aeruginosa Biofilm Production, Courtney Paige Turpin

Online Theses and Dissertations

Antibiotic-resistant bacteria have become an increasing burden worldwide. A highly resistant species is Pseudomonas aeruginosa, a nosocomial pathogen that produces a biofilm that enhances its resistance. This project examined the possibility of using bacteriocin, an internal protective toxin produced by some species of bacteria, as a potential treatment for resistant bacteria. In this study, standard broad spectrum antibiotics were used to treat P. aeruginosa to prevent biofilm formation. The biofilm was then analyzed to determine if the biofilm is inhibited or facilitated by each treatment. Optimal concentrations of antibiotics were determined to be effective at a concentration of 0.07mg ...


Effects Of Carbon Quantity And Plant Diversity On Pathogen Suppression By Soil-Borne Streptomyces, Nuttapon Pombubpa Jan 2015

Effects Of Carbon Quantity And Plant Diversity On Pathogen Suppression By Soil-Borne Streptomyces, Nuttapon Pombubpa

Undergraduate Honors Theses

Members of the genus Streptomyces are some of the best candidates for biological control of soil-borne pathogenic bacteria. Antibiotic production by Streptomyces is thought to be crucial for this strain’s ability to compete with other closely related soil microorganisms. Furthermore, Streptomyces is able to not only inhibit the growth of its competitors, but also that of many soil-borne plant pathogens. My thesis assessed Streptomyces performance under varying levels of soil resources (carbon componds that serve as energy sources) and in plots with varying degrees of plant diversity that, in turn, affects soil resources. This project aims to deconvolute the ...


The Effect Of O Antigen Loss On The Protein Composition And Inflammatory Response Elicited By Klebsiella Pneumoniae, Bethaney Cahill Jan 2015

The Effect Of O Antigen Loss On The Protein Composition And Inflammatory Response Elicited By Klebsiella Pneumoniae, Bethaney Cahill

UNF Graduate Theses and Dissertations

Klebsiella pneumoniae is a Gram-negative pathogen associated with numerous infections. Like all Gram-negative bacteria, K. pneumoniae naturally release outer membrane vesicles (OMVs) during all stages of cellular growth. OMVs are composed of the outer membrane components such as lipopolysaccharide (LPS) and outer membrane proteins and contain cytosolic and periplasmic proteins in the lumen. K. pneumoniae is often found to lack an O antigen. The absence of the O antigen has been reported to alter the protein content of the membrane which may further alter the immune response elicited by K. pneumoniae. Therefore the purpose of this study was to analyze ...