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Pathogenic Microbiology Commons

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2015

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Articles 1 - 21 of 21

Full-Text Articles in Pathogenic Microbiology

Protection Against Experimental Cryptococcosis Following Vaccination With Glucan Particles Containing Cryptococcus Alkaline Extracts, Charles A. Specht, Chrono K. Lee, Haibin Huang, Donald J. Tipper, Zu T. Shen, Jennifer K. Lodge, John D. Leszyk, Gary R. Ostroff, Stuart M. Levitz Dec 2015

Protection Against Experimental Cryptococcosis Following Vaccination With Glucan Particles Containing Cryptococcus Alkaline Extracts, Charles A. Specht, Chrono K. Lee, Haibin Huang, Donald J. Tipper, Zu T. Shen, Jennifer K. Lodge, John D. Leszyk, Gary R. Ostroff, Stuart M. Levitz

Infectious Diseases and Immunology Publications and Presentations

A vaccine capable of protecting at-risk persons against infections due to Cryptococcus neoformans and Cryptococcus gattii could reduce the substantial global burden of human cryptococcosis. Vaccine development has been hampered though, by lack of knowledge as to which antigens are immunoprotective and the need for an effective vaccine delivery system. We made alkaline extracts from mutant cryptococcal strains that lacked capsule or chitosan. The extracts were then packaged into glucan particles (GPs), which are purified Saccharomyces cerevisiae cell walls composed primarily of β-1,3-glucans. Subcutaneous vaccination with the GP-based vaccines provided significant protection against subsequent pulmonary infection with highly virulent ...


Data From: A Higher Activation Threshold Of Memory Cd8+ T Cells Has A Fitness Cost That Is Modified By Tcr Affinity During Tuberculosis, Stephen M. Carpenter, Claudio Nunes-Alves, Matthew G. Booty, Sing Sing Way, Samuel M. Behar Dec 2015

Data From: A Higher Activation Threshold Of Memory Cd8+ T Cells Has A Fitness Cost That Is Modified By Tcr Affinity During Tuberculosis, Stephen M. Carpenter, Claudio Nunes-Alves, Matthew G. Booty, Sing Sing Way, Samuel M. Behar

MaPS Research Data

Manuscript abstract: T cell vaccines against Mycobacterium tuberculosis (Mtb) and other pathogens are based on the principle that memory T cells rapidly generate effector responses upon challenge, leading to pathogen clearance. Despite eliciting a robust memory CD8+ T cell response to the immunodominant Mtb antigen TB10.4 (EsxH), we find the increased frequency of TB10.4-specific CD8+ T cells conferred by vaccination to be short-lived after Mtb challenge. To compare memory and naïve CD8+ T cell function during their response to Mtb, we track their expansions using TB10.4-specific retrogenic CD8+ T cells. We find that the primary (naïve) response ...


Utilizing Cmp-Sialic Acid Analogs To Unravel Neisseria Gonorrhoeae Lipooligosaccharide-Mediated Complement Resistance And Design Novel Therapeutics, Sunita Gulati, Ian C. Schoenhofen, Dennis M. Whitfield, Andrew D. Cox, Jianjun Li, Frank St Michael, Evgeny V. Vinogradov, Jacek Stupak, Bo Zheng, Makoto Ohnishi, Magnus Unemo, Lisa A. Lewis, Rachel E. Taylor, Corinna S. Landig, Sandra Diaz, George W. Reed, Ajit Varki, Peter A. Rice, Sanjay Ram Dec 2015

Utilizing Cmp-Sialic Acid Analogs To Unravel Neisseria Gonorrhoeae Lipooligosaccharide-Mediated Complement Resistance And Design Novel Therapeutics, Sunita Gulati, Ian C. Schoenhofen, Dennis M. Whitfield, Andrew D. Cox, Jianjun Li, Frank St Michael, Evgeny V. Vinogradov, Jacek Stupak, Bo Zheng, Makoto Ohnishi, Magnus Unemo, Lisa A. Lewis, Rachel E. Taylor, Corinna S. Landig, Sandra Diaz, George W. Reed, Ajit Varki, Peter A. Rice, Sanjay Ram

Open Access Articles

Neisseria gonorrhoeae deploys a novel immune evasion strategy wherein the lacto-N-neotetraose (LNnT) structure of lipooligosaccharide (LOS) is capped by the bacterial sialyltransferase, using host cytidine-5'-monophosphate (CMP)-activated forms of the nine-carbon nonulosonate (NulO) sugar N-acetyl-neuraminic acid (Neu5Ac), a sialic acid (Sia) abundant in humans. This allows evasion of complement-mediated killing by recruiting factor H (FH), an inhibitor of the alternative complement pathway, and by limiting classical pathway activation ("serum-resistance"). We utilized CMP salts of six additional natural or synthetic NulOs, Neu5Gc, Neu5Gc8Me, Neu5Ac9Ac, Neu5Ac9Az, legionaminic acid (Leg5Ac7Ac) and pseudaminic acid (Pse5Ac7Ac), to define structural requirements of Sia-mediated serum-resistance. While ...


Donor Platelet Plasma Components Inactivate Sensitive And Multidrug Resistant Acinetobacter Baumannii Isolates, Chelsea M. Edelblute, Olga N. Pakhomova, Fanying Li, Barbara Y. Hargrave, Loree C. Heller Dec 2015

Donor Platelet Plasma Components Inactivate Sensitive And Multidrug Resistant Acinetobacter Baumannii Isolates, Chelsea M. Edelblute, Olga N. Pakhomova, Fanying Li, Barbara Y. Hargrave, Loree C. Heller

Bioelectrics Publications

Acinetobacter baumannii is an environmentally resilient healthcare-associated opportunistic pathogen responsible for infections at many body sites. In the last 10 years, clinical strains resistant to many or all commonly used antibiotics have emerged globally. With few antimicrobial agents in the pharmaceutical pipeline, new and alternative agents are essential. Platelets secrete a large number of proteins, including proteins with antimicrobial activity. In a previous study, we demonstrated that donor platelet supernatants and plasma significantly inhibited the growth of a reference strain of A. baumannii in broth and on skin. This inhibition appeared to be unrelated to the platelet activation state. In ...


A Lipidomics Approach To The Viral-Host Dynamics Of The Unicellular, Eukaryotic Alga Chlorella Variabilis And Its Viral Pathogen, Pbcv-1, Suzanne Rose Dec 2015

A Lipidomics Approach To The Viral-Host Dynamics Of The Unicellular, Eukaryotic Alga Chlorella Variabilis And Its Viral Pathogen, Pbcv-1, Suzanne Rose

Dissertations and Theses in Biological Sciences

This thesis focuses on the sterol and sphingolipid composition in the unicellular, green alga Chlorella variabilis and the lipidomic changes that occur during viral infection. Using lipid analysis by mass spectrometry, we have identified the major sterol, ergosterol and sphingolipid, glucosyl inositol phosphoceramide (GIPC) as constituents of C. variabilis cell membranes. Sterols and sphingolipids have essential biological functions such as hormone-based signaling, plant defense, and apoptosis as well as critical roles in structural components of the cell and organelle membranes. In chapters two and three, we focus on the characterization of sterol composition among both freshwater and marine alga and ...


Dna-Containing Immunocomplexes Promote Inflammasome Assembly And Release Of Pyrogenic Cytokines By Cd14+ Cd16+ Cd64high Cd32low Inflammatory Monocytes From Malaria Patients, Isabella C. Hirako, Carolina Gallego-Marin, Marco A. Ataide Oswalso Cruz Founda, Warrison A. Andrade, Humberto Gravina, Bruno C. Rocha, Rosane B. De Oliveira, Dhelio B. Pereira, Joseph Vinetz, Betty Diamond, Sanjay Ram, Douglas T. Golenbock, Ricardo T. Gazzinelli Nov 2015

Dna-Containing Immunocomplexes Promote Inflammasome Assembly And Release Of Pyrogenic Cytokines By Cd14+ Cd16+ Cd64high Cd32low Inflammatory Monocytes From Malaria Patients, Isabella C. Hirako, Carolina Gallego-Marin, Marco A. Ataide Oswalso Cruz Founda, Warrison A. Andrade, Humberto Gravina, Bruno C. Rocha, Rosane B. De Oliveira, Dhelio B. Pereira, Joseph Vinetz, Betty Diamond, Sanjay Ram, Douglas T. Golenbock, Ricardo T. Gazzinelli

Open Access Articles

High levels of circulating immunocomplexes (ICs) are found in patients with either infectious or sterile inflammation. We report that patients with either Plasmodium falciparum or Plasmodium vivax malaria have increased levels of circulating anti-DNA antibodies and ICs containing parasite DNA. Upon stimulation with malaria-induced ICs, monocytes express an NF-kappaB transcriptional signature. The main source of IC-induced proinflammatory cytokines (i.e., tumor necrosis factor alpha [TNF-alpha] and interleukin-1beta [IL-1beta])in peripheral blood mononuclear cells from acute malaria patients was found to be a CD14(+) CD16 (FcgammaRIIIA)(+) CD64 (FcgammaRI)(high) CD32 (FcgammaRIIB)(low) monocyte subset. Monocytes from convalescent patients were predominantly of ...


Spectrum Of Histopathological Findings In Postmenopausal Bleeding, Muhammad Usman Tariq, Romana Idress, Ahmed Raheem, Naila Kayani Nov 2015

Spectrum Of Histopathological Findings In Postmenopausal Bleeding, Muhammad Usman Tariq, Romana Idress, Ahmed Raheem, Naila Kayani

Department of Pathology and Laboratory Medicine

Objective:To determine the frequencies of histopathological findings in endometrial and endocervical biopsy samples with clinical history of Postmenopausal Bleeding (PMB). Study Design:Descriptive cross-sectional study. Place and Duration of Study:Section of Histopathology, Department of Pathology and Laboratory Medicine, The Aga Khan University Hospital, Karachi, from February 2012 to January 2013. Methodology:Atotal of 157 consecutive endometrial and endocervical biopsy specimens with history of postmenopausal bleeding were included. After microscopic examination, frequencies of histological findings in different age groups were generated. Chi-square and independent sample t-tests were applied to see whether the difference was significant which was set at ...


Rnasek Is A V-Atpase-Associated Factor Required For Endocytosis And The Replication Of Rhinovirus, Influenza A Virus, And Dengue Virus, Jill Perreira, Aaron Aker, George Savidis, Christopher R. Chin, William M. Mcdougall, Jocelyn M. Portmann, Paul Meraner, Miles Smith, Motiur Rahman, Richard E. Baker, Annick Gauthier, Michael Franti, Abraham L. Brass Aug 2015

Rnasek Is A V-Atpase-Associated Factor Required For Endocytosis And The Replication Of Rhinovirus, Influenza A Virus, And Dengue Virus, Jill Perreira, Aaron Aker, George Savidis, Christopher R. Chin, William M. Mcdougall, Jocelyn M. Portmann, Paul Meraner, Miles Smith, Motiur Rahman, Richard E. Baker, Annick Gauthier, Michael Franti, Abraham L. Brass

Open Access Articles

Human rhinovirus (HRV) causes upper respiratory infections and asthma exacerbations. We screened multiple orthologous RNAi reagents and identified host proteins that modulate HRV replication. Here, we show that RNASEK, a transmembrane protein, was needed for the replication of HRV, influenza A virus, and dengue virus. RNASEK localizes to the cell surface and endosomal pathway and closely associates with the vacuolar ATPase (V-ATPase) proton pump. RNASEK is required for endocytosis, and its depletion produces enlarged clathrin-coated pits (CCPs) at the cell surface. These enlarged CCPs contain endocytic cargo and are bound by the scissioning GTPase, DNM2. Loss of RNASEK alters the ...


Eif2alpha Confers Cellular Tolerance To S. Aureus Alpha-Toxin, Gisela Von Hoven, Claudia Neukirch, Martina Meyenburg, Sabine Fuser, Maria Bidna Petrivna, Amable J. Rivas, Alexey Ryazanov, Randal J. Kaufman, Raffi V. Aroian, Matthias Husmann Jul 2015

Eif2alpha Confers Cellular Tolerance To S. Aureus Alpha-Toxin, Gisela Von Hoven, Claudia Neukirch, Martina Meyenburg, Sabine Fuser, Maria Bidna Petrivna, Amable J. Rivas, Alexey Ryazanov, Randal J. Kaufman, Raffi V. Aroian, Matthias Husmann

Open Access Articles

We report on the role of conserved stress-response pathways for cellular tolerance to a pore forming toxin. First, we observed that small molecular weight inhibitors including of eIF2alpha-phosphatase, jun-N-terminal kinase (JNK), and PI3-kinase sensitized normal mouse embryonal fibroblasts (MEFs) to the small pore forming S. aureus alpha-toxin. Sensitization depended on expression of mADAM10, the murine ortholog of a proposed high-affinity receptor for alpha-toxin in human cells. Similarly, eIF2alpha (S51A/S51A) MEFs, which harbor an Ala knock-in mutation at the regulated Ser51 phosphorylation site of eukaryotic translation initiation factor 2alpha, were hyper-sensitive to alpha-toxin. Inhibition of translation with cycloheximide did not ...


Virulence Of Group A Streptococci Is Enhanced By Human Complement Inhibitors, David Ermert, Jutamas Shaughnessy, Thorsten Joeris, Jakub Kaplan, Catherine J. Pang, Evelyn A. Kurt-Jones, Peter A. Rice, Sanjay Ram, Anna M. Blom Jul 2015

Virulence Of Group A Streptococci Is Enhanced By Human Complement Inhibitors, David Ermert, Jutamas Shaughnessy, Thorsten Joeris, Jakub Kaplan, Catherine J. Pang, Evelyn A. Kurt-Jones, Peter A. Rice, Sanjay Ram, Anna M. Blom

Open Access Articles

Streptococcus pyogenes, also known as Group A Streptococcus (GAS), is an important human bacterial pathogen that can cause invasive infections. Once it colonizes its exclusively human host, GAS needs to surmount numerous innate immune defense mechanisms, including opsonization by complement and consequent phagocytosis. Several strains of GAS bind to human-specific complement inhibitors, C4b-binding protein (C4BP) and/or Factor H (FH), to curtail complement C3 (a critical opsonin) deposition. This results in diminished activation of phagocytes and clearance of GAS that may lead to the host being unable to limit the infection. Herein we describe the course of GAS infection in ...


Prokaryotic Diversity In The Rhizosphere Of Organic, Intensive, And Transitional Coffee Farms In Brazil, Adam Caldwell, Livia Silva, Cynthia Da Silva, Cleber Ouverney Jun 2015

Prokaryotic Diversity In The Rhizosphere Of Organic, Intensive, And Transitional Coffee Farms In Brazil, Adam Caldwell, Livia Silva, Cynthia Da Silva, Cleber Ouverney

Faculty Publications

Despite a continuous rise in consumption of coffee over the past 60 years and recent studies showing positive benefits linked to human health, intensive coffee farming practices have been associated with environmental damage, risks to human health, and reductions in biodiversity. In contrast, organic farming has become an increasingly popular alternative, with both environmental and health benefits. This study aimed to characterize and determine the differences in the prokaryotic soil microbiology of three Brazilian coffee farms: one practicing intensive farming, one practicing organic farming, and one undergoing a transition from intensive to organic practices. Soil samples were collected from 20 ...


Human And Murine Clonal Cd8+ T Cell Expansions Arise During Tuberculosis Because Of Tcr Selection, Claudio Nunes-Alves, Matthew G. Booty, Stephen M. Carpenter, Alissa C. Rothchild, Constance J. Martin, Danielle Desjardins, Katherine Steblenko, Henrik N. Kløverpris, Rajhmun Madansein, Duran Ramsuran, Alasdair Leslie, Margarida Correia-Neves, Samuel M. Behar May 2015

Human And Murine Clonal Cd8+ T Cell Expansions Arise During Tuberculosis Because Of Tcr Selection, Claudio Nunes-Alves, Matthew G. Booty, Stephen M. Carpenter, Alissa C. Rothchild, Constance J. Martin, Danielle Desjardins, Katherine Steblenko, Henrik N. Kløverpris, Rajhmun Madansein, Duran Ramsuran, Alasdair Leslie, Margarida Correia-Neves, Samuel M. Behar

Microbiology and Physiological Systems Publications and Presentations

The immune system can recognize virtually any antigen, yet T cell responses against several pathogens, including Mycobacterium tuberculosis, are restricted to a limited number of immunodominant epitopes. The host factors that affect immunodominance are incompletely understood. Whether immunodominant epitopes elicit protective CD8+ T cell responses or instead act as decoys to subvert immunity and allow pathogens to establish chronic infection is unknown. Here we show that anatomically distinct human granulomas contain clonally expanded CD8+ T cells with overlapping T cell receptor (TCR) repertoires. Similarly, the murine CD8+ T cell response against M. tuberculosis is dominated by TB10.44-11-specific T cells ...


Data From: Human And Murine Clonal Cd8+ T Cell Expansions Arise During Tuberculosis Because Of Tcr Selection, Claudio Nunes-Alves, Matthew G. Booty, Stephen Carpenter, Alissa C. Rothchild, Constance J. Martin, Danielle Desjardins, Katherine Steblenko, Henrik Kloverpris, Rajhmun Madansein, Duran Ramsuran, Alasdair Leslie, Margarida Correia-Neves, Samuel M. Behar Apr 2015

Data From: Human And Murine Clonal Cd8+ T Cell Expansions Arise During Tuberculosis Because Of Tcr Selection, Claudio Nunes-Alves, Matthew G. Booty, Stephen Carpenter, Alissa C. Rothchild, Constance J. Martin, Danielle Desjardins, Katherine Steblenko, Henrik Kloverpris, Rajhmun Madansein, Duran Ramsuran, Alasdair Leslie, Margarida Correia-Neves, Samuel M. Behar

MaPS Research Data

Manuscript abstract: The immune system can recognize virtually any antigen, yet T cell responses against several pathogens, including Mycobacterium tuberculosis, are restricted to a limited number of immunodominant epitopes. The host factors that affect immunodominance are incompletely understood. Whether immunodominant epitopes elicit protective CD8+ T cell responses or instead act as decoys to subvert immunity and allow pathogens to establish chronic infection is unknown. Here we show that anatomically distinct human granulomas contain clonally expanded CD8+ T cells with overlapping T cell receptor (TCR) repertoires. Similarly, the murine CD8+ T cell response against M. tuberculosis is dominated by TB10.44-11-specific ...


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 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.


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 ...


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 ...


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 ...