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Full-Text Articles in Organisms

Resolving The Repression Pathway Of Virulence Gene Hila In Salmonella, Alexandra King, Lon Chubiz Phd, Brenda Pratte, Lauren Daugherty Jun 2022

Resolving The Repression Pathway Of Virulence Gene Hila In Salmonella, Alexandra King, Lon Chubiz Phd, Brenda Pratte, Lauren Daugherty

Undergraduate Research Symposium

Salmonella is a relatively abundant, virulent species of bacteria that is most known for spreading gastrointestinal diseases through food. These illnesses result in approximately 1.35 million infections, including over 25,000 hospitalizations each year, in the U.S. alone (CDC.gov). As antibiotic resistance becomes an increasingly urgent public health problem, the importance of developing alternative treatment methods is only becoming more crucial. One of the genes responsible for this virulence is known as hilA. HilA is the main transcriptional regulator of Salmonella Pathogenicity Island-1 gene (UniProt). SPI-1 plays an important role in the invasion of Salmonella into epithelial cells. The proteins encoded …


Diversity Of Bacteriophage In Burkholderia Species, Abigail Price Apr 2022

Diversity Of Bacteriophage In Burkholderia Species, Abigail Price

Honors Projects

Bacteriophages are viruses that infect and replicate within bacteria and offer the potential of a therapeutic alternative to chronic infections that do not respond to antibiotic-based therapies. B. vietnamiensis is one of a number of Burkholderia species involved with chronic drug resistant infections in the lungs of individuals with compromised respiratory systems, as found in those with chronic obstructive pulmonary disease and, most especially, are of particular significance in patients with cystic fibrosis. The diversity of the Burkholderia species is explored by using online databases and looking at bacteriophage or phage-encoding viruses found in B. vietnamiensis. The open reading frames …


The Large And Small Of It: The Microbiome And Metagenomics, Austin Hopkins, Elaina Gollmar, Jessica Fernandez, Shawn Wolf, Austin Hilverding, Andrew M. Roecker Mar 2022

The Large And Small Of It: The Microbiome And Metagenomics, Austin Hopkins, Elaina Gollmar, Jessica Fernandez, Shawn Wolf, Austin Hilverding, Andrew M. Roecker

Pharmacy and Wellness Review

Metagenomics, the analysis of the microbial genome, permits scientists to understand the influences of external sources including diet, metabolism and antibiotics on the human microbiome. Research has revealed the possibility of a core symbiosis between humans and bacteria. The main role of the human microbiome is to aid in digestion, but identified ancillary roles include immunologic homeostasis and infection prevention. Quantifying the composition and variability of the microbiome will help lead to future treatments or preventive strategies against unhealthy change. A variety of methods may be used to define the microbiome, and 16S amplicon sequencing is primarily utilized today. Probiotics …


Increasing Antibiotic Resistance In Shigella Bacteria In The United States, William J. Pharr Nov 2020

Increasing Antibiotic Resistance In Shigella Bacteria In The United States, William J. Pharr

The Corinthian

Shigella bacteria cause half a million infections, 6,000 hospitalizations, and 70 deaths annually in the United States. These bacteria are of particular concern due to their high survivability, low infectious dose, and high adaptability. Cases of shigellosis from Shigella sonnei are becoming a more prevalent issue in the U.S. as the bacteria continues to develop higher resistance to today’s strongest antibiotics. Much of this resistance is connected to the exchange of genes between strains of Shigella due to insertion sequences (IS), intercontinental travel, and men who have sex with men (MSM). As a result of increased resistance, the use of …


Response Of Extensively Drug Resistant Salmonella Typhi To Treatment With Meropenem And Azithromycin, In Pakistan, Sonia Qureshi, Abdullah B. Naveed, Mohammad Tahir Yousafzai, Khalil Ahmad, Sarwat Ansari, Heeramani Lohana, Aiman Mukhtar, Farah Naz Qamar Oct 2020

Response Of Extensively Drug Resistant Salmonella Typhi To Treatment With Meropenem And Azithromycin, In Pakistan, Sonia Qureshi, Abdullah B. Naveed, Mohammad Tahir Yousafzai, Khalil Ahmad, Sarwat Ansari, Heeramani Lohana, Aiman Mukhtar, Farah Naz Qamar

Department of Paediatrics and Child Health

Introduction: Salmonella Typhi is one of the leading health problems in Pakistan. With the emergence of extensively drug resistant (XDR) Salmonella Typhi, treatment options are limited. Here we report the clinical manifestations and the response to treatment of patients with XDR Typhoid fever. The patients were treated with either Meropenem or Azithromycin or a combination of both.
Methods: We reviewed the records of culture confirmed XDR typhoid who visited Aga Khan University Hospital (AKUH), Karachi and Aga Khan Secondary Care Hospital, Hyderabad from April 2017 to June 2018. Symptoms developed during disease, unplanned treatment extension and complications developed while on …


Plasmodium Impairs Antibacterial Innate Immunity To Systemic Infections In Part Through Hemozoin-Bound Bioactive Molecules., Christopher Lynn Harding Aug 2020

Plasmodium Impairs Antibacterial Innate Immunity To Systemic Infections In Part Through Hemozoin-Bound Bioactive Molecules., Christopher Lynn Harding

Electronic Theses and Dissertations

Despite efforts to decrease the global health burden of malaria, infections with Plasmodium species continue to cause over 200 million episodes of malaria each year which resulted in 405,000 deaths in 2018 [1]. One complication of malaria is increased susceptibility to invasive bacterial infections. Plasmodium infections impair host immunity to non-Typhoid Salmonella (NTS) through activities of heme oxygenase I (HO-I) )-induced release of immature granulocytes and myeloid cell-derived IL-10. Yet, it is not known if these mechanisms are specific to NTS. We show here, that Plasmodium yoelii 17XNL (Py) infected mice had impaired clearance of systemic Listeria monocytogenes (Lm) during …


Fecal Microbiota Transplantation And Gut Microbiome Effects On Psychiatric Illnesses, Mona Seresht Jun 2020

Fecal Microbiota Transplantation And Gut Microbiome Effects On Psychiatric Illnesses, Mona Seresht

Physician Assistant Studies | Student Articles

Despite the medical advances that have been made in regards to mental health, psychiatric medications, and alternative therapies, many patients continue to suffer day in and day out, unable to live the type of life they desire. Many times, the medication route includes many episodes of trial and error, side effects, and no significant improvement in actual symptoms. Therapy, although effective, typically necessitates a supplemental medication for the best results. Fecal microbiota transplantation (FMT) is a method where feces from a healthy donor is transferred to an affected patient, typically via colonoscopy. Theoretically, this alters the gut microbiome in a …


Hexadecane Petroleum, And Biofuel Utilization In Marine Bacteria Isolated From Ballast Tanks, Alex Yashchenko May 2020

Hexadecane Petroleum, And Biofuel Utilization In Marine Bacteria Isolated From Ballast Tanks, Alex Yashchenko

College of Arts & Sciences

This study characterized the growth of bacteria isolated from ballast tank fluids in hexadecane, petroleum, plant, and algae-derived fuels. The study was performed to explore the capacity of ballast tank isolates to survive and grow within fuels that may be stored within ballast tanks. Results of the hexadecane analysis indicated that most isolates had higher viable cell counts in media supplemented with hexadecane. Members of Alteromonas, Pseudoalteromonas, and a single Brevundimonas species had viable cell counts that were one or several orders ofmagnitude greater than that of controls. Results offuel analysis indicated higher viable cell counts in pure JP-5 and …


Characterization Of The Physical And Chemical Effect Of Membrane Disruption And Protein Inhibiting Treatments On E. Coli, Khadijah Wright Jan 2020

Characterization Of The Physical And Chemical Effect Of Membrane Disruption And Protein Inhibiting Treatments On E. Coli, Khadijah Wright

Honors Undergraduate Theses

The increase in antibacterial resistance has placed the issue of microbial multi-drug resistance on a global stage (Gurunathan, 2019). This issue poses a threat to human and animal health as well as to the environment (Aslam et al., 2018). It affects not only the efficacy of treatment but also how those treatments are conducted (Friedman, Temkin, & Carmeli, 2016). As a result of this ongoing threat, new treatments that have potent effects on bacteria are necessary. One scientific response to this issue has been the development of multifunctional nanoparticles (NPs)(H. Wang et al., 2018). NPs have the ability to be …


Genetic Signatures For Helicobacter Pylori Strains Of West African Origin, Kennady K. Bullock, Carrie L. Shaffer, Andrew W. Brooks, Ousman Secka, Mark H. Forsyth, Mark S. Mcclain, Timothy L. Cover Nov 2017

Genetic Signatures For Helicobacter Pylori Strains Of West African Origin, Kennady K. Bullock, Carrie L. Shaffer, Andrew W. Brooks, Ousman Secka, Mark H. Forsyth, Mark S. Mcclain, Timothy L. Cover

Veterinary Science Faculty Publications

Helicobacter pylori is a genetically diverse bacterial species that colonizes the stomach in about half of the human population. Most persons colonized by H. pylori remain asymptomatic, but the presence of this organism is a risk factor for gastric cancer. Multiple populations and subpopulations of H. pylori with distinct geographic distributions are recognized. Genetic differences among these populations might be a factor underlying geographic variation in gastric cancer incidence. Relatively little is known about the genomic features of African H. pylori strains compared to other populations of strains. In this study, we first analyzed the genomes of …


A Platform For The Discovery And Characterization Of Proteins That Associate With Pseudomonas Aeruginosa Rna Polymerase, Danielle N. Brogren Aug 2017

A Platform For The Discovery And Characterization Of Proteins That Associate With Pseudomonas Aeruginosa Rna Polymerase, Danielle N. Brogren

All NMU Master's Theses

Pseudomonas aeruginosa is an opportunistic bacterial pathogen notable for its ability to colonize the lungs of cystic fibrosis patients. Once the bacterium infects and colonizes humans, it is extremely difficult to eradicate. This leads to long-term infections that significantly damage the lungs and other tissues. P. aeruginosa infections are challenging to treat due to the bacterium’s natural antibiotic resistance and the rise of multidrug resistant strains. Development of novel drug treatments are a necessity.

In all organisms, the regulation of gene expression is a highly controlled process. Remarkably, in P. aeruginosa bioinformatics studies showed that 20% of its genome is …


Role Of Intracellular Growth During The Gastrointestinal Stage Of Listeria Monocytogenes Infection, Grant Steven Jones Jan 2017

Role Of Intracellular Growth During The Gastrointestinal Stage Of Listeria Monocytogenes Infection, Grant Steven Jones

Theses and Dissertations--Microbiology, Immunology, and Molecular Genetics

Listeria monocytogenes is a facultative intracellular bacterium that causes foodborne disease in humans. L. monocytogenes invade the gut mucosa and then disseminate, causing systemic infections associated with high mortality rates in immunocompromised individuals. It is unknown how L. monocytogenes traffic to the mesenteric lymph nodes, which represent an important bottleneck for systemic spread. In addition, little is known about the gastrointestinal stage of infection due to the general resistance of mice to oral infection with L. monocytogenes. Our laboratory developed a novel foodborne mouse model of listeriosis utilizing a murinized strain of L. monocytogenes to investigate the gastrointestinal stage …


Laboratory Exercises In Microbiology: Discovering The Unseen World Through Hands-On Investigation, Joan Petersen, Susan Mclaughlin Oct 2016

Laboratory Exercises In Microbiology: Discovering The Unseen World Through Hands-On Investigation, Joan Petersen, Susan Mclaughlin

Open Educational Resources

The exercises in this laboratory manual are designed to engage students in hand-on activities that reinforce their understanding of the microbial world. Topics covered include: staining and microscopy, metabolic testing, physical and chemical control of microorganisms, and immunology. The target audience is primarily students preparing for a career in the health sciences, however many of the topics would be appropriate for a general microbiology course as well.


Changing Diagnostic Methods And Increased Detection Of Verotoxigenic Escherichia Coli, Ireland, Thomas Rice, Noreen Quinn, Roy D. Sleator, Brigid Lucey Sep 2016

Changing Diagnostic Methods And Increased Detection Of Verotoxigenic Escherichia Coli, Ireland, Thomas Rice, Noreen Quinn, Roy D. Sleator, Brigid Lucey

Department of Biological Sciences Publications

The recent paradigm shift in infectious disease diagnosis from culture-based to molecular-based approaches is exemplified in the findings of a national study assessing the detection of verotoxigenic Escherichia coli infections in Ireland. The methodologic changes have been accompanied by a dramatic increase in detections of non-O157 verotoxigenic E. coli serotypes.


Optimization Of A Genomic Editing System Using Crispr/Cas9-Induced Site-Specific Gene Integration, Jillian L. Mccool Ms., Nick Hum, Gabriela G. Loots Aug 2016

Optimization Of A Genomic Editing System Using Crispr/Cas9-Induced Site-Specific Gene Integration, Jillian L. Mccool Ms., Nick Hum, Gabriela G. Loots

STAR Program Research Presentations

The CRISPR-Cas system is an adaptive immune system found in bacteria which helps protect against the invasion of other microorganisms. This system induces double stranded breaks at precise genomic loci (1) in which repairs are initiated and insertions of a target are completed in the process. This mechanism can be used in eukaryotic cells in combination with sgRNAs (1) as a tool for genome editing. By using this CRISPR-Cas system, in addition to the “safe harbor locus,” ROSAβ26, the incorporation of a target gene into a site that is not susceptible to gene silencing effects can be achieved through few …


Epidemiology Crucial To Cracking Elizabethkingia Crisis, Angela Tonozzi Apr 2016

Epidemiology Crucial To Cracking Elizabethkingia Crisis, Angela Tonozzi

Journal of Patient-Centered Research and Reviews

The author explains the epidemiological methods, tools and personnel required to pinpoint the source of Wisconsin’s 2016 outbreak of Elizabethkingia infections.


An Analysis Of Bacterial Contamination Of Chicken Eggs And Antimicrobial Resistance, Holly Spitzer Apr 2016

An Analysis Of Bacterial Contamination Of Chicken Eggs And Antimicrobial Resistance, Holly Spitzer

All College Thesis Program, 2016-2019

Chicken eggs are a major component of American diets, with an average yearly consumption of approximately 250 eggs per person (American Humane Society). While highly nutritious, eggs are also one of the leading causes of food poisoning and food borne illness in the United States. Eggs may become contaminated by a number of different types of bacteria during production, including Salmonella, a group of bacteria that, according to the CDC, causes more than 1.2 million cases of food borne illness in the United States every year. In an effort to decrease the frequency of bacterial contamination, many food producers …


Wake Me When It's Over- Bacterial Toxin-Antitoxin Proteins And Induced Dormancy, Nathan P. Coussens, Dayle A. Daines Jan 2016

Wake Me When It's Over- Bacterial Toxin-Antitoxin Proteins And Induced Dormancy, Nathan P. Coussens, Dayle A. Daines

Biological Sciences Faculty Publications

Toxin-antitoxin systems are encoded by bacteria and archaea to enable an immediate response to environmental stresses, including antibiotics and the host immune response. During normal conditions, the antitoxin components prevent toxins from interfering with metabolism and arresting growth; however, toxin activation enables microbes to remain dormant through unfavorable conditions that might continue over millions of years. Intense investigations have revealed a multitude of mechanisms for both regulation and activation of toxin-antitoxin systems, which are abundant in pathogenic microorganisms. This minireview provides an overview of the current knowledge regarding type II toxin-antitoxin systems along with their clinical and environmental implications.


Comparative Analysis Of Anti-Bd Bacteria From Six Malagasy Frog Species Of Ranomafana National Park, Kelsey Savage May 2015

Comparative Analysis Of Anti-Bd Bacteria From Six Malagasy Frog Species Of Ranomafana National Park, Kelsey Savage

Senior Honors Projects, 2010-2019

As Malagasy amphibians are facing an impending extinction crisis from the lethal skin fungus Batrachochytrium dendrobatidis (Bd), it has become imperative to proactively mitigate the threat. Bd sporangia develop in the skin of infected amphibians and cause the skin to thicken, leading to ionic imbalance and eventual heart failure. It has been shown that certain bacterial species are able to inhibit Bd growth on amphibians by producing antifungal metabolites. Community-based probiotics are one approach used to combat chytridomycosis by inoculating an environment with Bd-inhibitory bacteria so that many amphibian species are treated at once. With this method, it is important …


Examining Phage Infection Utilizing Mycobacterium Smegmatis, Tanya L. Riddick Apr 2015

Examining Phage Infection Utilizing Mycobacterium Smegmatis, Tanya L. Riddick

Undergraduate Research

Bacteriophages, also known as phages, are viruses that are ubiquitous and survive and replicate within the host of the bacterial cell, Mycobacterium smegmatis. They are considered one of the most abundant organisms on earth (1031). Structurally, they are 100-200nm in size and consist of a protein encapsulated head that contains DNA or RNA, a tail sheath and tail fibers. This research consisted of examining phage infection, by re-isolating a novel phage, Tango. Tango was originally isolated genetically in 2013 by a previous ISBT student, Anna Maccarrone. The phage was sent to genetic sequencing but two phages were discovered, …


Composition Of The Adult Digestive Tract Bacterial Microbiome Based On Seven Mouth Surfaces, Tonsils, Throat And Stool Samples, Nicola Segata, Susan Kinder Haake, Peter Mannon, Katherine P. Lemon, Levi Waldron, Dirk Gevers, Curtis Huttenhower, Jacques Izard Jun 2012

Composition Of The Adult Digestive Tract Bacterial Microbiome Based On Seven Mouth Surfaces, Tonsils, Throat And Stool Samples, Nicola Segata, Susan Kinder Haake, Peter Mannon, Katherine P. Lemon, Levi Waldron, Dirk Gevers, Curtis Huttenhower, Jacques Izard

Publications and Research

Background: To understand the relationship between our bacterial microbiome and health, it is essential to define the microbiome in the absence of disease. The digestive tract includes diverse habitats and hosts the human body’s greatest bacterial density. We describe the bacterial community composition of ten digestive tract sites from more than 200 normal adults enrolled in the Human Microbiome Project, and metagenomically determined metabolic potentials of four representative sites.

Results: The microbiota of these diverse habitats formed four groups based on similar community compositions: buccal mucosa, keratinized gingiva, hard palate; saliva, tongue, tonsils, throat; sub- and supra-gingival plaques; and stool. …


Interactions Of Francisella Tularensis With Components Of The Host Fibrinolytic System, Shawn Russell Clinton Dec 2010

Interactions Of Francisella Tularensis With Components Of The Host Fibrinolytic System, Shawn Russell Clinton

Theses and Dissertations (ETD)

Francisella tularensis (FT) is a Gram-negative coccobacillus and causative agent of a life-threatening disease commonly referred to as tularemia. Due to the highly infectious nature of the organism, its previous development as a biowarfare agent and its potential use in acts of bioterrorism, this bacterium is listed as a Category A select agent by the Centers for Disease Control and Prevention (CDC). Efforts to understand the pathogenic mechanisms of FT within the host environment are vital for the development of safe and effective vaccines, as well as treatments, against tularemia. Though considered an intracellular pathogen, FT research of late has …


Development Of Pyrf-Based Genetic System For Targeted Gene Deletion In Clostridium Thermocellum And Creation Of A Pta Mutant, Shital A. Tripathi, Daniel G. Olson, D. Aaron Argyros, Bethany B. Miller, Trisha F. Barrett, Daniel M. Murphy, Jesse D. Mccool, Anne K. Warner, Vineet B. Rajgarhia, Lee R. Lynd, David A. Hogsett, Nicky C. Caiazza Aug 2010

Development Of Pyrf-Based Genetic System For Targeted Gene Deletion In Clostridium Thermocellum And Creation Of A Pta Mutant, Shital A. Tripathi, Daniel G. Olson, D. Aaron Argyros, Bethany B. Miller, Trisha F. Barrett, Daniel M. Murphy, Jesse D. Mccool, Anne K. Warner, Vineet B. Rajgarhia, Lee R. Lynd, David A. Hogsett, Nicky C. Caiazza

Dartmouth Scholarship

We report development of a genetic system for making targeted gene knockouts in Clostridium thermocellum, a thermophilic anaerobic bacterium that rapidly solubilizes cellulose. A toxic uracil analog, 5-fluoroorotic acid (5-FOA), was used to select for deletion of the pyrF gene. The ΔpyrF strain is a uracil auxotroph that could be restored to a prototroph via ectopic expression of pyrF from a plasmid, providing a positive genetic selection. Furthermore, 5-FOA was used to select against plasmid-expressed pyrF, creating a negative selection for plasmid loss. This technology was used to delete a gene involved in organic acid production, namely pta, which encodes …


Pseudomonas Aeruginosa-Candida Albicans Interactions: Localization And Fungal Toxicity Of A Phenazine Derivative, Jane Gibson, Arpanah Sood, Deborah A. Hogan Nov 2008

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 …


Characterization Of The Omptin Protease, Ompt, In Escherichia Coli, Amanda Yates, Eun-Hae Kim, Helen Wing Aug 2008

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 …


The Effects Of Host Physiological Conditions On The Expression Of Icsp In Shigella Flexneri, Karen Levy, Helen Wing Aug 2008

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, …


Downstream Pathway Activation In Cultured Hepatocytes Following Treatment With Francisella Tularensis, Nicole Wakefield Apr 2007

Downstream Pathway Activation In Cultured Hepatocytes Following Treatment With Francisella Tularensis, Nicole Wakefield

Undergraduate Theses and Capstone Projects

Francisella tularensis, the intracellular pathogen that causes tularemia, was investigated to determine how it infects and replicates within mammalian hepatocytes. To date, it has been shown that hepatocytes can be infected by F. tularensis and that this causes considerable change in the protein phosphorylation state of several vital signaling molecules within the host cell. Protein kinase pathways can be mapped as signatures of infection. Hepatocytes tend to be susceptible to infection by F. tularensis, thus stimulating internal signaling. The Francisella strains used were selected with the goal of producing a model that can be used to elucidate the cell signaling …


Molecular Screening Of Azoreductase Gene And Its Activity In Human Intestinal Bacteria, Syndia S. Todd Dec 2006

Molecular Screening Of Azoreductase Gene And Its Activity In Human Intestinal Bacteria, Syndia S. Todd

McCabe Thesis Collection

The intestinal microflora are capable of performing a wide variety of metabolic transformations. "The intestinal bacteria can enhance the function of the entire gastrointestinal tract, protect against pathogenic, maintain the vital chemical balance of the gastrointestinal system, and produce needed vitamins and hormones" (http;//www.upwardquest.com/crit2.html). Some of the products of this metabolism have been associated with carcinogenic processes, such as cancer, tumor formation, gastrointestinal disease, and infections. The ability of human intestinal microbes to interact with metabolites directly or after recirculation may contribute toward different toxicological disorders and disease.

The purpose of this study is to characterize and isolate the azoreductase …


Metal-Resistance Genetically Engineered Bacteria, Sylvia Daunert, Donna Scott, Sridhar Ramanathan Jun 1996

Metal-Resistance Genetically Engineered Bacteria, Sylvia Daunert, Donna Scott, Sridhar Ramanathan

KWRRI Research Reports

Bacterial-based electrochemical and optical sensing systems that respond in a highly selective and sensitive manner to antimonite and arsenite have been developed. This was accomplished by using genetically engineered bacteria bearing one of two plasmids constructed for our studies. The first plasmid, pBGD23, contains the operator/promoter region (O/P) and the gene of the ArsR protein from the ars operon upstream from the β-galactosidase gene. In the absence of antimonite/arsenite, ArsR binds to the 0/P site and prevents the transcription of the genes for ArsR and β-galactosidase, thus blocking expression of these proteins. When antimonite or arsenite is present in the …


Movement Of Bacteria Through Macropores To Ground Water, M. Scott Smith, Grant W. Thomas, Robert E. White Jun 1983

Movement Of Bacteria Through Macropores To Ground Water, M. Scott Smith, Grant W. Thomas, Robert E. White

KWRRI Research Reports

Effects of soil type, flow rate, antecedent soil moisture and other factors on transport of E. coli through soils was measured on disturbed and intact columns 20 cm in diameter by 25 to 30 cm in depth. Added E. coli were distinguished from indigenous microbes using an antibiotic resistance marker. Transport of Cl- and 3H2O was also measured. Up to 96 percent of the bacteria irrigated onto the surface of intact columns were recovered in the effluent. Soil structure appeared to be related to the extent of transport. Columns prepared from mixed, repacked soil were much …