Microbiology Commons^™

Role Of Multicellular Aggregates In Biofilm Formation, Kasper N. Kragh, Jaime B. Hutchison, Gavin Melaugh, Chris Rodesney, Aled E. L. Roberts, Yasuhiko Irie, Peter Ø. Jensen, Stephen P. Diggle, Rosalind J. Allen, Vernita Gordon, Thomas Bjarnsholt

Biology Faculty Publications

In traditional models of in vitro biofilm development, individual bacterial cells seed a surface, multiply, and mature into multicellular, three-dimensional structures. Much research has been devoted to elucidating the mechanisms governing the initial attachment of single cells to surfaces. However, in natural environments and during infection, bacterial cells tend to clump as multicellular aggregates, and biofilms can also slough off aggregates as a part of the dispersal process. This makes it likely that biofilms are often seeded by aggregates and single cells, yet how these aggregates impact biofilm initiation and development is not known.

Here we use a combination of …

Post-Chemotherapy Neuroblastoma-Like Differentiation In Ewing Sarcoma Of Humerus: Report Of A Rare Case With Review Of Literature, Nasir Ud Din, Amna Qasim, Zubair Ahmad, Sheema H Hasan

Department of Pathology and Laboratory Medicine

A 21-year patient initially presented with a fracture of the humerus following minor trauma. A bone scan and biopsy were done due to the suspicion of pathological fracture and the biopsy confirmed the diagnosis of Ewing Sarcoma (EWS). Two months after initial presentation, chemotherapy was started and 5 cycles were given over a span of 6 months. Surgical resection of the tumor was then performed. The post-chemotherapy resection specimen, on histological examination, showed the presence of areas of neuroblastoma-like differentiation in otherwise morphologically classic EWS. Cytogenetic analysis by FISH revealed EWSR1 gene rearrangement. Four similar cases have been reported earlier …

How Important Is A Postdoc For A Teaching Career?, Amy Cheng Vollmer, V. Balke, C. Frantz, T. E. Hanson

Biology Faculty Works

No abstract provided.

The Transcription Factors Adr1 Or Cat8 Are Required For Rtg Pathway Activation And Evasion From Yeast Acetic Acid-Induced Programmed Cell Death In Raffinose, Zhengchang Liu, Luna Laera, Nicoletta Guaragnella, Maša Ždralević, Domenico Marzulli, Sergio Giannattasio

Biological Sciences Faculty Publications

Yeast Saccharomyces cerevisiae grown on glucose undergoes programmed cell death (PCD) induced by acetic acid (AA-PCD), but evades PCD when grown in raffinose. This is due to concomitant relief of carbon catabolite repression (CCR) and activation of mitochondrial retrograde signaling, a mitochondria-to-nucleus communication pathway causing up-regulation of various nuclear target genes, such as CIT2, encoding peroxisomal citrate synthase, dependent on the positive regulator RTG2 in response to mitochondrial dysfunction. CCR down-regulates genes mainly involved in mitochondrial respiratory metabolism. In this work, we investigated the relationships between the RTG and CCR pathways in the modulation of AA-PCD sensitivity under glucose repression …

Herpes Simplex Virus And Interferon Signaling Induce Novel Autophagic Clusters In Sensory Neurons, Sarah Katzenell, David A. Leib

Dartmouth Scholarship

Herpes simplex virus 1 (HSV-1) establishes lifelong infection in the neurons of trigeminal ganglia (TG), cycling between productive infection and latency. Neuronal antiviral responses are driven by type I interferon (IFN) and are crucial to controlling HSV-1 virulence. Autophagy also plays a role in this neuronal antiviral response, but the mechanism remains obscure. In this study, HSV-1 infection of murine TG neurons triggered unusual clusters of autophagosomes, predominantly in neurons lacking detectable HSV-1 antigen. Treatment of neurons with IFN-β induced a similar response, and cluster formation by infection or IFN treatment was dependent upon an intact IFN-signaling pathway. The autophagic …

Hyperactive Erk And Persistent Mtor Signaling Characterize Vemurafenib Resistance In Papillary Thyroid Cancer Cells, Elyse Hanly, Neha Y. Tuli, Robert B. Bednarczyk, Robert Suriano, Jan Geliebter, Augustine L. Moscatello, Zbigniew Darzynkiewicz, Raj K. Tiwari

NYMC Faculty Publications

Clinical studies evaluating targeted BRAFV600E inhibitors in advanced thyroid cancer patients are currently underway. Vemurafenib (BRAFV600E inhibitor) monotherapy has shown promising results thus far, although development of resistance is a clinical challenge. The objective of this study was to characterize development of resistance to BRAFV600E inhibition and to identify targets for effective combination therapy. We created a line of BCPAP papillary thyroid cancer cells resistant to vemurafenib by treating with increasing concentrations of the drug. The resistant BCPAP line was characterized and compared to its sensitive counterpart with respect to signaling molecules thought to be directly related to resistance. Expression …

The Two-Component System Cpxra Negatively Regulates The Locus Of Enterocyte Effacement Of Enterohemorrhagic Escherichia Coli Involving Σ32 And Lon Protease, Miguel A. De La Cruz, Jason K. Morgan, Miguel A. Ares, Jorge A. Yáñez-Santos, James T. Riordan, Jorge A. Girón

Molecular Biosciences Faculty Publications

Enterohemorrhagic Escherichia coli (EHEC) is a significant cause of serious human gastrointestinal disease worldwide. EHEC strains contain a pathogenicity island called the locus of enterocyte effacement (LEE), which encodes virulence factors responsible for damaging the gut mucosa. The Cpx envelope stress response of E. coli is controlled by a two-component system (TCS) consisting of a sensor histidine kinase (CpxA) and a cytoplasmic response regulator (CpxR). In this study, we investigated the role of CpxRA in the expression of LEE-encoded virulence factors of EHEC. We found that a mutation in cpxA significantly affected adherence of EHEC to human epithelial cells. Analysis …

Comparing Apples And Oranges?: Next Generation Sequencing And Its Impact On Microbiome Analysis, Adam G. Clooney, Fiona Fouhy, Roy D. Sleator, Aisling O'Driscoll, Stanton Catherine, Paul D. Cotter, Marcus J. Claesson

Department of Biological Sciences Publications

Rapid advancements in sequencing technologies along with falling costs present widespread opportunities for microbiome studies across a vast and diverse array of environments. These impressive technological developments have been accompanied by a considerable growth in the number of methodological variables, including sampling, storage, DNA extraction, primer pairs, sequencing technology, chemistry version, read length, insert size, and analysis pipelines, amongst others. This increase in variability threatens to compromise both the reproducibility and the comparability of studies conducted. Here we perform the first reported study comparing both amplicon and shotgun sequencing for the three leading next-generation sequencing technologies. These were applied to …

Discovery And Characterization Of Bacteriophage To Control Mrsa, Jacob B. Hatch, Bradford Berges

Journal of Undergraduate Research

About 20% of humans are carriers of Staphylococcus aureus (SA). There were an estimated 11,000 deaths in the United States in 2005 attributed to SA, with the majority caused by MRSA (Methicillin Resistant Staphylococcus Aureus) isolates [1]. Many MRSA isolates have developed resistance to all but one antibiotic drug: vancomycin. However, other bacteria have developed resistance to vancomycin, suggesting that in time MRSA will likewise become non-responsive to this last available drug and MRSA infections will be untreatable. This project looks to find an alternate method of MRSA treatment. Bacteriophage (phage) are viruses that infect bacterial cells in order …

The Role Of Pas Kinase And The Gut Microbiome In Metabolism And Diabetes Onset In Mice, Andrew Rees, Laura Bridgewater

Journal of Undergraduate Research

Diabetes and obesity are among the most prevalent health concerns in the modern world. However, prevention of their onset and control of their symptoms are still largely limited by our understanding of how these diseases arise. Recent research has indicated that the composition of the gut microbiome is one of the important factors in development of these diseases (5). However, current thinking is not definitive on the relative importance of genetic factors, diet and the gut microbiome, among other factors (5,6). PAS Kinase provided a model through which we could compare the relative affects of genetics, gut microbiome and diet …

Identification Of The Function Of A Unique B4 Mycobacteriophage Protein Via In Silico And In Vivo Analysis, Cameron Sargent, Dr. Julianne Grose

Journal of Undergraduate Research

Once the leading cause of death in the United States, tuberculosis still burdens the world as the second deadliest infectious disease worldwide, latently infecting one-third of the world population and causing 1.5 million deaths in 2013 [1]. Tuberculosis is particularly lethal largely because the pathogen Mycobacterium tuberculosis has several characteristics that make detecting, treating, and studying the disease unusually hard. Among these traits, M. tuberculosis has a complex cell wall that limits the effect of many antibiotics and makes genetic manipulation of the bacterium, a necessity for effective research, nearly impossible through conventional transformation techniques [2]. Recently, Howard Hughes Medical …

Single Nucleotide Polymorphisms And Accelerated Telomere Shortening, Rebecca Winner, Dr. Brent Nielsen

Journal of Undergraduate Research

Telomeres are protective deoxyribonucleic acid caps on the ends of chromosomes which help prevent the chromosome itself from shortening during replication. As a person ages, normal telomere shortening occurs due to chromosome replication. However, accelerated telomere shortening is abnormal and has been linked to several factors such as disease, depression, and anxiety.

This project aims to determine if underlying genetic factors that contribute to increased incidence of depression will produce accelerated telomere shortening as seen in subjects with a history of depression. SNP’s in genes that code for 5-HTT, a serotonin receptor, and DRD2, a dopamine receptor, have been shown …

Role Of The Viral Lana Protein In Human Cancers Caused By Kaposi’S Sarcoma-Associated Herpesvirus, Gregory Low, Brad Berges

Journal of Undergraduate Research

The purpose of our experiment was to ascertain the importance of the LANA protein encoded by the Kaposi’s Sarcoma-Associated Herpesvirus (KSHV). LANA is believed to be essential for the survival of KSHV in human cells. KSHV causes a variety of cancers including Kaposi’s sarcoma (KS), multicentric Castleman’s disease (MCD), and primary effusion lymphoma (PEL). These cancers most often appear in the immunocompromised and can be fatal. The mortality rate of PEL is ~60% after one year, KS 5-year mortality rate is ~30%, and MCD 5-year mortality rate is 35%. No known vaccine or anti-viral drug treatment is currently licensed for …

The Use Of Bacteriophage For Surface Sterilization Of Methicillin-Resistant Staphylococcus Aureus In Poultry Facilities, Trevor Wienclaw, Bradford Berges

Journal of Undergraduate Research

Staphylococcus aureus (SA) is potentially dangerous pathogen that can infect humans and animals alike¹. The primary treatment for such infections has been antibiotics, but even shortly after antibiotics began to be used, antibiotic-resistant strains, known as MRSA, were discovered. These resistant strains have since spread, and now account for over half of all clinical isolates⁴. A similar scenario developed in the livestock industry. Antibiotics have been used to treat diseased animals and to promote growth in healthy animals. This use lead to development of MRSA among these animals. These animals may merely be carriers or they …

Isolation And Characterization Of Novel Lytic Phage To Treat Mrsa, Tyler White, Bradford Berges

Journal of Undergraduate Research

The bacterium Staphylococcus Aureus is the cause of a serious skin disease that is known to cause life-threatening infections such as pneumonia, endocarditis, meningitis, sepsis, bacteremia, and toxic shock syndrome [1]. Nonetheless, most SA infections are readily remedied via antibiotic treatment with methicillin. However, over the course of frequent exposure to various antibiotics, the bacteria have evolved a mutant strain (MRSA) that is completely resistant to the drug. In 2005 an estimated 11,000 deaths occurred that can be attributed to SA, with the majority caused by MRSA isolates [2]. Albeit the mutant is named MRSA, isolates of this strain are …

Finding Clues To Phosphate Homeostasis Through Transposon Sequencing, Tanner Dean, William Mccleary

Journal of Undergraduate Research

Though Escherichia Coli is a thoroughly investigated species of bacteria, questions still remain concerning genes involved in phosphate homeostasis. Phosphate homeostasis is the idea that a cell or bacterium adapts to changing environmental phosphate concentrations. Cells need to adapt to changing phosphate conditions because phosphate is essential to the biochemistry of many cellular processes. A cell therefore, must be able to collect and store phosphate when there is excess or scavenge and utilize stored phosphate in times when there are low levels of extracellular phosphate available. This process is not entirely understood in E.coli or other single celled organisms. A …

Staphylococcus Aureus Nasal Carriage Among Beefpacking Workers In A Midwestern United States Slaughterhouse, Jessica Leibler, Jeanne A. Jordan, Kirsten Brownstein, Lina Lander, Lance B. Price, Melissa J. Perry

Environmental and Occupational Health Faculty Publications

Occupational contact with livestock is an established risk factor for exposure to livestock-associated methicillin-resistant Staphylococcus aureus (MRSA), particularly among industrial swine workers. While S. aureus is known to infect cattle, livestock-associated S. aureuscarriage among workers in the beef production chain has received limited attention. Beefpacking workers, who slaughter, butcher and process cattle, have intensified exposure to potentially infectious animal materials and may be at risk of livestock-associated S. aureusexposure. We conducted a cross-sectional study of beefpacking workers (n = 137) at an industrial slaughterhouse in the Midwestern United States to evaluate prevalence and characteristics of …

Global Regulator Of Virulence A (Grva) Coordinates Expression Of Discrete Pathogenic Mechanisms In Enterohemorrhagic Escherichia Coli Through Interactions With Gadw-Gade, Jason K. Morgan, Ronan K. Carroll, Carly M. Harro, Khoury W Vendura, Lindsey N. Shaw, James T. Riordan

Molecular Biosciences Faculty Publications

UNLABELLED: Global regulator of virulence A (GrvA) is a ToxR-family transcriptional regulator that activates locus of enterocyte effacement (LEE)-dependent adherence in enterohemorrhagic Escherichia coli (EHEC). LEE activation by GrvA requires the Rcs phosphorelay response regulator RcsB and is sensitive to physiologically relevant concentrations of bicarbonate, a known stimulant of virulence systems in intestinal pathogens. This study determines the genomic scale of GrvA-dependent regulation and uncovers details of the molecular mechanism underlying GrvA-dependent regulation of pathogenic mechanisms in EHEC. In a grvA-null background of EHEC strain TW14359, RNA sequencing analysis revealed the altered expression of over 700 genes, including the downregulation …

Primary Angiosarcoma Of Breast, Saroona Haroon, Naveen Faridi, Faisal Rashid Lodhi

Department of Pathology and Laboratory Medicine

Primary breast sarcomas, except for phyllodes tumour, are very rare entities, accounting for < 0.1% of all malignant neoplasms. Angiosarcoma of breast is infrequent malignancy and differential diagnosis from other sarcomatous and angiomatous breast tumours holds importance. Two cases of primary angiosarcoma of breast were encountered. One involved a 32 years lady who was treated by wide local excision and six cycles of chemotherapy. The other occurred in a 54 years old lady who was treated with mastectomy, did not receive any radiation or chemotherapy and was later lost to follow-up. Neither of the patient had history of previous breast surgery, chemotherapy or radiotherapy.

Creation Of An Eight-Member Plasmid Library For Promoter Swapping To Control Chromosomal Gene Expression In E. Coli, Matt Phillips, Dr. William Mccleary

Journal of Undergraduate Research

The ability to control gene expression in bacteria has been essential in solving problems in many fields, including medicine and environmental protection. Recent advances in genomic and metabolic modeling tools have led to the development of a new technique called promoter swapping which enables researchers to “swap” any native gene promoter with one that has been specifically engineered. Promoter swapping uses viral recombination proteins to swap DNA in the chromosome rather than in plasmids, allowing for constant and permanent expression levels. Our goal was to create eight template plasmids with promoters of increasing strengths to be used in promoter swapping. …