Microbiology Commons^™

Pseudomonas Aeruginosa-Candida Albicans Interactions: Localization And Fungal Toxicity Of A Phenazine Derivative, Jane Gibson, Arpanah Sood, Deborah A. Hogan

Dartmouth Scholarship

Phenazines are redox-active small molecules that play significant roles in the interactions between pseudomonads and diverse eukaryotes, including fungi. When Pseudomonas aeruginosa and Candida albicans were cocultured on solid medium, a red pigmentation developed that was dependent on P. aeruginosa phenazine biosynthetic genes. Through a genetic screen in combination with biochemical experiments, it was found that a P. aeruginosa-produced precursor to pyocyanin, proposed to be 5-methyl-phenazinium-1-carboxylate (5MPCA), was necessary for the formation of the red pigmentation. The 5MPCA-derived pigment was found to accumulate exclusively within fungal cells, where it retained the ability to be reversibly oxidized and reduced, and its …

Molecular Characterisation Of A Bovine-Like Rotavirus Detected From A Giraffe, Emily Mulherin, Jill Bryan, Marijke Beltman, Luke O'Grady, Eugene Pidgeon, Lucie Garon, Andrew Lloyd, John Bainbridge, Helen O'Shea, Paul Whyte, Séamus Fanning

Department of Biological Sciences Publications

Background

Rotavirus (RV), is a member of the Reoviridae family and an important etiological agent of acute viral gastroenteritis in the young. Rotaviruses have a wide host range infecting a broad range of animal species, however little is known about rotavirus infection in exotic animals. In this paper we report the first characterisation of a RV strain from a giraffe calf.

Results

This report describes the identification and detailed molecular characterisation of a rotavirus strain detected from a 14-day-old Giraffe (Giraffa camelopardalis), presenting with acute diarrhea. The RV strain detected from the giraffe was characterized molecularly as G10P[11]. …

Prevalence And Factors Associated With Intestinal Parasitic Infection Among Children In An Urban Slum Of Karachi., Vikram Mehraj, Juanita Hatcher, Saeed Akhtar, Ghazala Rafique, Mohammad Asim Beg

Department of Pathology and Laboratory Medicine

Background:Intestinal parasitic infections are endemic worldwide and have been described as constituting the greatest single worldwide cause of illness and disease. Poverty, illiteracy, poor hygiene, lack of access to potable water and hot and humid tropical climate are the factors associated with intestinal parasitic infections. The study aimed to estimate prevalence and identify factors associated with intestinal parasitic infections among 1 to 5 years old children residing in an urban slum of Karachi Pakistan. Methods And Principal
Findings:A cross sectional survey was conducted from February to June 2006 in Ghosia Colony Gulshan Town Karachi, Pakistan. A simple random …

Viral Vectors In The Research Laboratory: Just How Safe Are They?, Dawn P. Wooley, Kimberly Kay Morris, Robert Mcrae, John C. Trefry

Neuroscience, Cell Biology & Physiology Faculty Publications

No abstract provided.

Identification Of Two Gene Clusters And A Transcriptional Regulator Required For Pseudomonas Aeruginosa Glycine Betaine Catabolism, Matthew J. Wargo, Benjamin S. Szwergold, Deborah A. Hogan

Dartmouth Scholarship

Glycine betaine (GB), which occurs freely in the environment and is an intermediate in the catabolism of choline and carnitine, can serve as a sole source of carbon or nitrogen in Pseudomonas aeruginosa. Twelve mutants defective in growth on GB as the sole carbon source were identified through a genetic screen of a nonredundant PA14 transposon mutant library. Further growth experiments showed that strains with mutations in two genes, gbcA (PA5410) and gbcB (PA5411), were capable of growth on dimethylglycine (DMG), a catabolic product of GB, but not on GB itself. Subsequent nuclear magnetic resonance (NMR) experiments with 1,2-(13)C-labeled choline …

Global Analysis Of Gene Expression Changes During Retinoic Acid-Induced Growth Arrest And Differentiation Of Melanoma: Comparison To Differentially Expressed Genes In Melanocytes Vs Melanoma, Mary H. Estler, Goran Boskovic, James Denvir, Sarah Miles, Donald A. Primerano, Richard M. Niles

Biochemistry and Microbiology

BACKGROUND: The incidence of malignant melanoma has significantly increased over the last decade. Some of these malignancies are susceptible to the growth inhibitory and pro-differentiating effects of all-trans-retinoic acid (RA). The molecular changes responsible for the biological activity of RA in melanoma are not well understood.

RESULTS: In an analysis of sequential global gene expression changes during a 4-48 h RA treatment of B16 mouse melanoma cells, we found that RA increased the expression of 757 genes and decreased the expression of 737 genes. We also compared the gene expression profile (no RA treatment) between non-malignant melan-a mouse melanocytes and …

The Cradle Of The Deltaf508 Mutation, Danish Saleheen, Philippe M Frossard

Department of Biological & Biomedical Sciences

Cystic fibrosis (CF) is the most common autosomal recessive disorder caused due to mutation/s in the CFTR gene. The most common mutation in CFTR worldwide is deltaF508 and cystic fibrosis genetic analysis consortium revealed that this mutation is responsible for approximately 66% of all CF chromosomes in the world. Studies looking at the DNA polymorphic haplotypes created by CF linked markers suggest that deltaF508 has a single origin as this mutation has been found associated exclusively with one marker haplotype. Despite a high prevalence of this mutation in CF patients in northern parts of Europe, findings suggest that this mutation …

The Bile Response Repressor Brer Regulates Expression Of The Vibrio Cholerae Breab Efflux System Operon, Francisca A. Cerda-Maira, Carol S. Ringelberg, Ronald K. Taylor

Dartmouth Scholarship

Enteric pathogens have developed several resistance mechanisms to survive the antimicrobial action of bile. We investigated the transcriptional profile of Vibrio cholerae O1 El Tor strain C6706 under virulence gene-inducing conditions in the presence and absence of bile. Microarray analysis revealed that the expression of 119 genes was affected by bile. The mRNA levels of genes encoding proteins involved in transport were increased in the presence of bile, whereas the mRNA levels of genes encoding proteins involved in pathogenesis and chemotaxis were decreased. This study identified genes encoding transcriptional regulators from the TetR family (vexR and breR) and …

The Effects Of Host Physiological Conditions On The Expression Of Icsp In Shigella Flexneri, Karen Levy, Helen Wing

Undergraduate Research Opportunities Program (UROP)

Shigella flexneri is a gram-negative bacterium capable of causing diarrhea and dysentery known as shigellosis. It is estimated there are 167.4 million shigellosis episodes throughout the world each year causing 1.1 million deaths. Shigella invades cells in the lower intestine through an induced phagocytosis. Once in the cytoplasm, bacteria move from one cell to another using actin-based motility. The Shigella outer membrane protease IcsP regulates actin-based motility and cell-to-cell spread by cleaving the actin assembly protein IcsA from the bacterial cell surface. We hypothesize that IcsP may serve additional functions during infection. By examining which environmental signals trigger icsP expression, …

Characterization Of The Omptin Protease, Ompt, In Escherichia Coli, Amanda Yates, Eun-Hae Kim, Helen Wing

Undergraduate Research Opportunities Program (UROP)

Omptins are outer membrane proteases found in gram negative bacteria that cause diseases in humans, such as pathogenic Escherichia coli, Shigella flexneri, Salmonella typhimurium, and Yersinia pestis. Bacterial species that express omptins cause diseases such as highly fatal plague and severe diarrhea and dysentery. The genes that encode these proteases are ompT, icsP, pgtE, and pla, respectively. These proteases are highly related in structure and share approximately 50% sequence identity. In S. flexneri, IcsP has been shown to cleave a key virulence determinant, IcsA (Egile et al., 1997). IcsA recruits host actin and allows for intracellular movement within host cells …

Relationship Of Lactobacillus Casei To Prevention Of Antibiotic Associated Diarrhea Due To Clostridium Difficile, Kayal K. Chandramohan

All-Inclusive List of Electronic Theses and Dissertations

The purpose of this research was to study the effectiveness of Lactobacillus casei in preventing the occurrence of antibiotic associated diarrhea related to Clostridium difficile. Twenty-six patients, above the age of sixty years, who were prescribed antibiotic therapy and admitted to the Rehabilitation or Orthopedics Units at Union Hospital and who met the eligibility criteria were recruited for the study. Equal numbers of patients (13 in each group) were assigned to the Control and the Experimental group based on their admission date to the hospital and their willingness to consume a probiotic yogurt type drink. The patients in the experimental …

Infectious Keratitis Associated With Contact Lens Use, Misty Dawn Harvey

All-Inclusive List of Electronic Theses and Dissertations

In March 2006, ophthalmologists noticed increased Fusarium keratitis in patients wearing soft contact lenses; the etiology was that of Fusarium solani. By May of 2006, CDC reported receiving a total of 130 confirmed cases of Fusarium keratitis across 26 states and one territory; of the 118 who could identify the lens solution they had used, 64% reported using Bausch & Lomb's ReNu with Moistureloc ©,while 18% reported using only non-Bausch & Lomb products. The association between Fusarium keratitis and ReNu with Moistureloc was not clear. Nevertheless, Bausch & Lomb withdrew Moistureloc solutions worldwide. In earlier laboratory tests using standard methods …

Time Trends In The Incidence Of Cancer Cervix In Karachi South, 1995-2002, Yasmin Bhurgri, Shahid Pervez, Naila Kayani, Muneeza Afif, Imran Tahir, Kauser Nazir, Ahmed Usman, Naveen Faridi, Hadi Bhurgri, Jawaid Malik, Imtiaz Bashir, Asif Bhurgri, Rashida Ahmed, Sheema H Hasan, Mohammad Khurshid, S. M. H. Zaidi

Department of Pathology and Laboratory Medicine

Introduction:The objective of the study was to determine the trends of cancer cervix in Karachi South during an eight (1995-2002) year period. Methododology: Cancer cervix cases recorded at Karachi Cancer Registry during 1st January 1995 to 31st December 2002 were analyzed. Trends were studied by analyzing the age standardized incidence rates (ASR)s in 2 time periods, 1995-97 and 1998-2002.

Results:

Cancer cervix ranked sixth in the 1995-97 period the age standardized incidence rate (ASR) world and crude incidence rate (CIR) per 100,000 were 6.81 and 3.22. It reached the fifth ranking in the 1998-2002 period with an ASR and …

Emergence Of Carbapenem Resistant Gram Negative And Vancomycin Resistant Gram Positive Organisms In Bacteremic Isolates Of Febrile Neutropenic Patients: A Descriptive Study., Seema Irfan, Faiza Idrees, Vikram Mehraj, Faizah Habib, Salman Adil, Rumina Hasan

Department of Pathology and Laboratory Medicine

Background:This study was conducted to evaluate drug resistance amongst bacteremic isolates of febrile neutropenic Patients with particular emphasis on emergence of carbapenem resistant Gram negative bacteria and vancomycin resistant Enterococcus species.

Methods:

A descriptive study was performed by reviewing the blood culture reports from febrile neutropenic Patients during the two study periods i.e., 1999-00 and 2001-06. Blood cultures were performed using BACTEC 9240 automated system. Isolates were identified and antibiotic sensitivities were done using standard microbiological procedures.

Results:

Seven twenty six febrile neutropenic Patients were admitted during the study period. A total of 5840 blood cultures were received, off …

Oxidative Stress-Mediated Anticancer Activity Of Novel Ahr Modulators Af & 5f203, Lancelot S. Mclean

Loma Linda University Electronic Theses, Dissertations & Projects

Estrogen receptor positive (ER+) breast cancer tends to respond to anti-estrogen agents such as Tamoxifen. Approximately 40% of ER+ breast cancer is resistant to these agents and those that initially respond often acquire resistance. Estrogen receptor negative (ER-) breast cancer remains largely unresponsive to these agents. It is therefore vital to discover drugs that are potent in both forms of breast cancer. Aminoflavone, (5-amino-2, 3-fluorophenyl)-6,8-difluoro-7-methyl-4H-l-benzopyran-4-one; AF; NSC 686288) and 5F203, (2-[-Amino-3-methy phenyl]-5-flurobenzothiazole) are novel anticancer candidate agents that display potent in vitro and in vivo anti-proliferative activity against select human tumor cells with a unique anticancer activity profile in the …

Effect Of Short Exposure Of Naoci/Edta On E. Faecalis In Extracted Human Teeth, Rylan N. Gustafson

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this project was to study the antibacterial effect of the short exposure of 5.25% NaOCl and 17% EDTA on eight strains of Enterococcus faecalis in extracted human teeth. The crowns of 240 single rooted teeth were removed and the canals were instrumented to ISO 0.36. The canals were irrigated with 5.25% NaOCl and 17% EDTA, autoclaved and separated into eight groups of 30 teeth consisting of 20 experimental teeth, 5 positive and 5 negative controls. Each group was inoculated with one of eight different strains of E. faecalis in BHl broth and incubated for four weeks. The …

Novel Binding Domains Mediate Binding Of Hpv 16 E6 To Fadd And Procaspase 8, Sandy S. Tungteakkhun

Loma Linda University Electronic Theses, Dissertations & Projects

To evade the host response to infection, viruses have developed means to survive and propagate. HPV 16, a causative agent of cervical cancer and of some cases of oropharyngeal cancers, is one example. We have reported that the early viral protein E6 binds to proteins necessary for propagation of the apoptotic signal following receptor/ligand interactions, such as those mediated by FADD DED and procaspase 8 DED. E6 expression leads to the dose-dependent accelerated degradation of FADD and the protection of E6-expressing cells from Fas-induced apoptosis. Surprisingly, the splice isoforms of E6, E6_large and E6*, affect the stability of procaspase …

Mechanisms Of T Helper Cell Modulation In A Simulated Space Radiation Environment, Asma Rizvi

Loma Linda University Electronic Theses, Dissertations & Projects

Exposure to solar particle events (SPEs) poses the most serious threat to astronaut health. Due to this radiation environment, exploration of the solar system beyond Earth’s orbit entails many risks for the crew on these deep space missions. Depression or dysfunction of the immune system is a major concern due to its high radio-sensitivity; potential consequences include overwhelming infection, development of cancer, fibrosis, and poor wound healing. Astronauts are also exposed to low dose/low dose rate (LDR) radiation. A three month stay at the international space station exposes them to ~ 0.05 Gy of radiation.

C57BL/6 mice received LDR gamma-radiation …

Precipitating Factors Of Hepatic Encephalopathy In Patients With Chronic Liver Disease At Civil Hospital Karachi, Dileep K Rohra, Jaipal, Ameer A Khowaja, Khalid Mahmood, Kanya Lal Ahuja

Department of Biological & Biomedical Sciences

No abstract provided.

Diagnostic Tool For Glanzmann's Thrombasthenia Clinicopathologic Spectrum, Natasha Bahadur Ali, Bushra Moiz, Mohammad Usman Shaikh, Salman Adil, Bushra Rizvi, Yasmeen Rahman

Department of Pathology and Laboratory Medicine

Objective: To platelet aggregometry and describe the clinical spectrum of Glanzmann's thrombasthenia diagnosed by platelet aggregometry.
Study design: A case-series.
Place and duration of study: This study was carried out at the clinical laboratories at the Aga Khan University Hospital, Karachi from January 2003 to January 2006.
Patients and methods: All patients irrespective of age and gender presenting with bleeding symptoms and having normal platelet count were evaluated. Demographic details, relevant clinical history along with results of complete blood count, bleeding time and platelet aggregation studies were retrieved through computerized data base and evaluated for the diagnosis of Glanzmann's thrombasthenia. …

Role Of Transient Receptor Potential Canonical-6 (Trpc6) Channel In Metastasis Of Glioblastoma Multiforme, Rajarajeshwari Venkataraman

Electronic Theses and Dissertations

Glioblastoma multiforme (GBM) is one of the extremely fatal brain tumors. The main reason that makes it so lethal is its capability to invade and spread to other parts of CNS producing secondary tumors. Among other factors hypoxia, reduced oxygen availability, is linked to higher metastatic potential of cancers. Hypoxia causes numerous changes in genome and proteome of the cell. These changes help a normal cell to adapt to nutritional deficiency, but the same changes can increase the malignancy and metastasis in tumor cells. Extensive research by a number of curious scientists reveal that various pathways involving numerous proteins cross-talk …

Evaluation Of The Efficacy Of Chloroplast-Derived Antigensagainst Malaria, Melissa Schreiber

Electronic Theses and Dissertations

Malaria is the most prevalent vector-borne parasitic disease worldwide and a major cause of death from infections. There is a great need to develop a low cost vaccine for malaria to control transmission of infection and impact of disease, due to the emergence of anti-malarial resistance. Two leading blood stage malarial vaccine candidates are the apical membrane antigen-1 (AMA-1) and the merozoite surface protein-1 (MSP-1). The aim of this project is to express malarial antigens in tobacco plants via plastid transformation and deliver them by subcutaneous or oral gavage of minimally processed transplastomic tissue to evaluate their efficacy to elicit …

Generation Of Recombinant Mouse Embryonic Stem Cell Lines And Theirapplication For In Vivo Bioluminiscence Imaging In The Heart, Ramana Kammili

Electronic Theses and Dissertations

Cardiovascular disease is the major cause of death in the United States, with 80 million people suffering from some form of heart disease each year. One major limitation is the inability of the heart to repair the damaged tissue. Stem cell therapy holds enormous promise to repair and regenerate the damaged myocardium, but there are many technical difficulties that must first be overcome. One such difficulty is the present lack of ability to track and assess transplanted stem cells over time in vivo. The central hypothesis of this thesis is that in vivo bioluminescence imaging is a safe and useful …

Do Hospitalists Or Physicians With Greater Inpatient Hiv Experience Improve Hiv Care In The Era Of Highly Active Antiretroviral Therapy? Results From A Multicenter Trial Of Academic Hospitalists, John A. Schneider, Qi Zhang, Andrew Auerbach, David Gonzales, Peter Kaboli, Jeffrey Schnipper, Tosha B. Wetterneck, David L. Pitrak, David O. Meltzer

Community & Environmental Health Faculty Publications

Background. Little is known about the effect of provider type and experience on outcomes, resource use, and processes of care of hospitalized patients with human immunodeficiency virus (HIV) infection. Hospitalists are caring for this population with increasing frequency.

Methods. Data from a natural experiment in which patients were assigned to physicians on the basis of call cycle was used to study the effects of provider type—that is, hospitalist versus non hospitalist—and HIV-specific inpatient experience on resource use, outcomes, and selected measures of processes of care at 6 academic institutions. Administrative data, inpatient interviews, 30-day follow-up interviews, and the National Death …

A Versatile Assay For The Identification Of Rna Silencing Suppressors Based On Complementation Of Viral Movement, Jason G. Powers, Tim L. Sit, Feng Qu, T. Jack Morris, Kook-Hyung Kim, Steven A. Lommel

Nebraska Center for Virology: Faculty Publications

The cell-to-cell movement of Turnip crinkle virus (TCV) in Nicotiana benthamiana requires the presence of its coat protein (CP), a known suppressor of RNA silencing. RNA transcripts of a TCV construct containing a reporter gene (green fluorescent protein) (TCV-sGFP) in place of the CP open reading frame generated foci of three to five cells. TCV CP delivered in trans by Agrobacterium tumefaciens infiltration potentiated movement of TCV-sGFP and increased foci diameter, on average, by a factor of four. Deletion of the TCV movement proteins in TCV-sGFP (construct TCVΔ92-sGFP) abolished the movement complementation ability of TCV CP. Other known suppressors of …

Detection And Molecular Epidemiological Analysis Of Acute Gastroenteritis Viruses In The South Of Ireland, Grainne Lennon

Theses

Rotavirus infections are considered to be the most common cause of severe gastroenteritis in children under the age of 5 years, and are responsible for up to 611,000 deaths annually, mainly in developing countries. From 1997 to 1999, 16 hospital laboratories in the Republic of Ireland reported to detection of 4,643 cases of rotaviral disease, while in 2004 and 2005 and increase of 1,600 and 2,251 rotavirus cases were reported. These rotavirus cases have a significant impact on the healthcare system with the minimum cost per case being €728.40. A large percentage of the infections were reported in neonates, suggesting …

Development Of An Immunofluorescence Assay Using Recombinant Proteins Expressed In Insect Cells To Screen And Confirm Presence Of Human Herpesvirus 8-Specific Antibodies, Veenu Minhas, Lynsey N. Crosby, Kay L. Crabtree, Saul Phiri, Tendai J. M'Soka, Chipepo Kankasa, William J. Harrington, Charles D. Mitchell, Charles Wood

Nebraska Center for Virology: Faculty Publications

Human herpesvirus 8 (HHV-8), or Kaposi’s sarcoma (KS)-associated herpesvirus, has been linked to all forms of KS. The results of most current serological assays for the detection of HHV-8-specific antibodies have low levels of concordance among themselves. To establish a sensitive and specific testing strategy that can be used to screen for HHV-8-specific antibodies, three HHV-8 proteins, ORF65, ORF73, and K8.1A, were expressed by using baculoviral vectors in insect cells and incorporated into a monoclonal antibodyenhanced immunofluorescence assay (mIFA) termed the Sf9 three-antigen mIFA. The results obtained by this mIFA were compared to those obtained by a standard mIFA with …

Small-Molecule Cd4 Mimics Interact With A Highly Conserved Pocket On Hiv-1 Gp120, Navid Madani, Arne Schön, Amy M. Princiotto, Judith M. Lalonde, Joel R. Cpurter, Takahiro Soeta, Danny Ng, Liping Wang, Evan T. Brower, Shi-Hua Xiang, Young Do Kwon, Chih-Chin Huang, Richard Wyatt, Peter D. Kwong, Ernesto Freire, Amos B. Smith Iii, Joseph Sodroski

Nebraska Center for Virology: Faculty Publications

Human immunodeficiency virus (HIV-1) interaction with the primary receptor, CD4, induces conformational changes in the viral envelope glycoproteins that allow binding to the CCR5 second receptor and virus entry into the host cell. The small molecule NBD-556 mimics CD4 by binding the gp120 exterior envelope glycoprotein, moderately inhibiting virus entry into CD4-expressing target cells, and enhancing CCR5 binding and virus entry into CCR5-expressing cells lacking CD4. Studies of NBD-556 analogues and gp120 mutants suggest that: 1) NBD-556 binds within the Phe 43 cavity, a highly conserved, functionally important pocket formed as gp120 assumes the CD4- bound conformation; 2) the NBD-556 …

The Human Immunodeficiency Virus Type 1 Envelope Confers Higher Rates Of Replicative Fitness To Perinatally Transmitted Viruses Than To Nontransmitted Viruses, Xiaohong Kong, John T. West, Hong Zhang, Danielle M. Shea, Tendai J. M’Soka, Charles Wood

Nebraska Center for Virology: Faculty Publications

Selection of a minor viral genotype during perinatal transmission of human Immunodeficiency virus type 1

(HIV-1) has been observed, but there is a lack of information on the correlation of the restrictive transmission

with biological properties of the virus, such as replicative fitness. Recombinant viruses expressing the enhanced

green fluorescent protein or the Discosoma sp. red fluorescent (DsRed2) protein carrying the V1 to V5

regions of env from seven mother-infant pairs (MIPs) infected by subtype C HIV-1 were constructed, and

competition assays were carried out to compare the fitness between the transmitted and nontransmitted

viruses. Flow cytometry was used to …

Varying Efficiency Of Long-Term Replication Of Papillomaviruses In Saccharomyces Cerevisiae, Adam J. Rogers, Malte Loggen, Karen Lee, Peter C. Angeletti

Nebraska Center for Virology: Faculty Publications

Human papillomaviruses (HPVs) replicate in mitotically active basal keratinocytes. Two virally encoded proteins, E1, a helicase, and E2, a transcription factor, are important players in replication and maintenance of HPV episomes. We previously showed that HPV16 could replicate stably in Saccharomyces cerevisiae [Angeletti, P.C., Kim, K., Fernandes, F.J., and Lambert, P.F. (2002)] and we identified cis-elements that mediate replication and maintenance [J. Virol. 76(7), 3350-3358.; Kim, K., Angeletti, P.C., Hassebroek, E.C., and Lambert, P.F. (2005)]. Here, we demonstrate that although multiple HPV genomes replicate stably in yeast, they do so with differing long-term efficiency; HPV6-Ura3 is replicated at the …