Bacteriology Commons^™

Aerobic Degradation Of Α-, Β-, Γ-Hexachlorocyclohexane By Narragansett Bay Bacterioplankton, Ian M. Rambo

Senior Honors Projects

Hexachlorocyclohexanes (HCHs) are a family of chlorinated organic compounds that were previously used as agricultural insecticides. HCHs are recognized as persistent organic pollutants due to their toxicity, recalcitrant properties, and tendency to bioaccumulate in food webs. Although HCH was first synthesized in 1825, its use was not widespread until the discovery of the insecticidal activity of the γ-HCH isomer in 1942. γ-HCH and its toxic waste isomers α-HCH and β-HCH were banned from production and use by the United Nations in 2009, yet these chemicals still present environmental problems due to their persistence in soils and surface waters. HCHs continue ...

Prevalence Of Avian-Pathogenic Escherichia Coli Strain O1 Genomic Islands Among Extraintestinal And Commensal E. Coli Isolates, Timothy J. Johnson, Yvonne Wannemuehler, Subhashinie Kariyawasam, James R. Johnson, Catherine M. Logue, Lisa K. Nolan

Veterinary Microbiology and Preventive Medicine Publications and Papers

Escherichia coli strains that cause disease outside the intestine are known as extraintestinal pathogenic E. coli (ExPEC) and include pathogens of humans and animals. Previously, the genome of avian-pathogenic E. coli (APEC) O1:K1:H7 strain O1, from ST95, was sequenced and compared to those of several other E. coli strains, identifying 43 genomic islands. Here, the genomic islands of APEC O1 were compared to those of other sequenced E. coli strains, and the distribution of 81 genes belonging to 12 APEC O1 genomic islands among 828 human and avian ExPEC and commensal E. coli isolates was determined. Multiple islands ...

Phenotypic And Genotypic Characterization Of Escherichia Coli Isolated From Untreated Surface Waters, Steven L. Daniel, Kai F. Hung, Kristopher J. Janezic, Blake Ferry, Eric W. Hendricks, Brian A. Janiga, Tiffany Johnson, Samantha Murphy, Morgan E. Roberts, Sarah M. Scott, Alexandra N. Theisen

Steven L. Daniel

A common member of the intestinal microbiota in humans and animals is Escherichia coli. Based on the presence of virulence factors, E. coli can be potentially pathogenic. The focus of this study was to isolate E. coli from untreated surface waters (37 sites) in Illinois and Missouri and determine phenotypic and genotypic diversity among isolates. Water samples positive for fecal coliforms based on the Colisure® test were streaked directly onto Eosin Methylene Blue (EMB) agar (37°C) or transferred to EC broth (44.5°C). EC broth cultures producing gas were then streaked onto EMB agar. Forty-five isolates were identified ...

Survey Of Antibiotic Resistant Bacteria In Fish Gut Collected From Selected Sites, Hasina Karki

Master's Theses

Antibiotics and antibiotic resistant bacteria have been detected in the aquatic system around the world. We wanted to know whether the wild fish population from Cedar Creek watershed in Indiana and reference site in Michigan had any antibiotic resistant microbes in their gut samples. Additionally we wanted to test hatchery-raised fish for the same reason. The main objectives were to 1) isolate antibiotic resistant bacteria that might be present in the fish guts, 2) determine the antibiotic resistance phenotype of resistant isolates, and 3) to test for the presence of plasmids in selected resistant isolates. Freshwater field fish species were ...

Modifying Commercially Available Vectors For Expression Of Standardized Igem Biobricks, Merhawi T. Yigzaw, Dafna Lapido, Holly M. Bowman

Georgia State Undergraduate Research Conference

No abstract provided.

Construction Of A Tetracycline-Inducible System For Controlled Gene Expression In Crithidia Fasciculata, Fatima I. Hussain, Sanela Andelija

Georgia State Undergraduate Research Conference

No abstract provided.

Regulation Of The Escherichia Coli Hipba Toxin-Antitoxin System By Proteolysis, Sonja Hansen, Marin Vulić, Tien-Jui Yen, Maria A. Schumacher, Richard G. Brennan, Kim Lewis

Biology Faculty Publications

Bacterial populations produce antibiotic-tolerant persister cells. A number of recent studies point to the involvement of toxin/antitoxin (TA) modules in persister formation. hipBA is a type II TA module that codes for the HipB antitoxin and the HipA toxin. HipA is an EF-Tu kinase, which causes protein synthesis inhibition and dormancy upon phosphorylation of its substrate. Antitoxins are labile proteins that are degraded by one of the cytosolic ATP-dependent proteases. We followed the rate of HipB degradation in different protease deficient strains and found that HipB was stabilized in a lon^- background. These findings were confirmed in an in ...

Developing Generally Applicable Tools To Investigate Tetr Family Transcriptional Regulators, Sang Kyun Ahn

Open Access Dissertations and Theses

Bacteria adapt to changes in their environment by regulating gene transcription. TetR family transcriptional regulators (TFRs) constitute one of the largest groups of bacterial transcription factors and thus, characterization of TFRs is anticipated to be crucial for a better understanding of prokaryotic physiology. Of significant importance, the majority of TFRs are predicted to respond to small-molecule signals and an emerging paradigm suggests that identifying ligands of TFRs can provide direct insight into the biochemical functions of the genes they regulate. Regulatory target genes and small-molecule ligands are unknown for all but a few TFRs and therefore, generally applicable tools for ...

The Evolution Of Host Specificity In The Vertebrate Gut Symbiont Lactobacillus Reuteri, Steven Frese

Dissertations & Theses in Food Science and Technology

The vertebrate gut is home to one of the densest populations of life on Earth. This microbial community has a profound effect on host health, nutrition, development, behavior, and evolution. However, very little is known about how these microbes have evolved with their vertebrate hosts, how and whether they select hosts or how they remain associated with their hosts. Recent work identified Lactobacillus reuteri as an organism that is composed of host-specific sub-populations, each population associated with a different host animal. Representatives from each host-associated population were tested for their ability to colonize gnotobiotic mice, which only rodent strains could ...

Cure From The Cave: Volcanic Cave Actinomycetes And Their Potential In Drug Discovery, Naowarat (Ann) Cheeptham Dr., Tara Sadoway, Devon Rule, Kent Watson, Paul Moote, Laiel C. Soliman, Nicholas Azad, Kingsley Donkor, Derrick Horne

International Journal of Speleology

Volcanic caves have been little studied for their potential as sources of novel microbial species and bioactive compounds with new scaffolds. We present the first study of volcanic cave microbiology from Canada and suggest that this habitat has great potential for the isolation of novel bioactive substances. Sample locations were plot ted on a contour map that was compiled in ArcView 3.2. Over 400 bacterial isolates were obtained from the Helmcken Falls cave in Wells Gray Provincial Park, British Columbia. From our preliminary screen, of 400 isolates tested, 1% showed activity against extended spectrum ß-lactamase E. coli, 1.75 ...

Efficacy Comparison Of Various Pcr Master Mixes And Thermal Cycling Parameters For Detection Of Brucella Abortus In Multiplex Assays, Kevin J. Testo, Jason A. Olivas, Alda C. Carrillo, Pejman Naraghi-Arani

STEM Teacher and Researcher (STAR) Program Posters

Diagnostic testing for bioterrorism agents in food is essential for the safety and welfare of the general populace. Multiplex assays provide the means to test for multiple pathogen signatures with a single polymerase chain reaction (PCR) test. PCR, Luminex xMAP ® infrared fluorophore bead technology, and flow cytometry, multiplex diagnostic assays are incredibly specific and sensitive to highly conserved regions at various loci in a microbe’s genome. In order to increase the effectiveness of the PCR and the resulting fluorescent response of the beads, different PCR master mix commercial kits were compared to the standard AgPath RT-PCR mix. This study ...

Sequesteration Of Lead, Cadmium And Arsenic By Lactobacillus Species And Detoxication Potential, Marc A. Monachese

Electronic Thesis and Dissertation Repository

Toxic metals are a class of elements with no biological role but with extreme toxicity. On average only 50% of ingested toxins are absorbed into the human body, for reasons still unknown. It was hypothesized that the gut microbiota plays a role in reducing toxin absorbance. The aim of this study was to determine if constituents of the gut, namely Lactobacillus species, are able to sequester arsenic, lead and cadmium from the environment. Lactobacilli were incubated with the metals, both in vitro and with a Caco-2 cell line. Analysis of metal concentrations was conducted to determine if these were reduced ...

Production And Degradation Of 4-Ethylphenol In Lactobacillus Sp. Pep8 Cultures And In Blended Swine Lagoon Enrichments, Clinton W. Copp

Masters Theses & Specialist Projects

4-Ethylphenol (4-EP) is a malodorant of swine waste and is derived from a component of lignin called p-coumaric acid (p-CA). The production of 4-EP from lignin in swine waste is untested. Additionally, the effect of Fe (III) on 4-EP levels is unknown. Four experiments were performed to determine if Lactobacillus sp. pep8 cultures, as well as enriched swine lagoon slurries, could liberate p-CA from lignin and convert p-CA to 4-EP. Furthermore, it was tested if the addition of Fe (III) influences the conversion of p- CA to 4-EP.

Experiment 1 tested Lactobacillus sp. pep8 cultures to determine if the addition ...

Colonization Of Zea Mays By The Nitrogen Fixing Bacterium Gluconacetobacter Diazotrophicus, Nikita Eskin

Electronic Thesis and Dissertation Repository

To achieve high yields, corn fields are supplemented with nitrogen fertilizers. Nitrogen fertilizers account for a significant portion of production costs, and are harmful to the environment. Gluconacetobacter diazotrophicus, an endophytic nitrogen-fixing bacterium supplies its natural host sugarcane with a significant amount of nitrogen. This study investigated the colonization of G. diazotrophicus in seven different corn genotypes consisting of sweet and grain corn via three different methods of inoculation: soil drench, root dip, and aseptic inoculation. Sucrose content of the corn genotypes and nitrogenase activity were also analysed. Colonization was confirmed by PCR analysis. G. diazotrophicus colonization was detected using ...