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Genetics and Genomics Commons

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Full-Text Articles in Genetics and Genomics

Emergence Of The L Phenotype In Group B Streptococci In The South Of Ireland, Katherine Hayes, Lesley Cotter, L. Barry, Fiona O'Halloran Nov 2017

Emergence Of The L Phenotype In Group B Streptococci In The South Of Ireland, Katherine Hayes, Lesley Cotter, L. Barry, Fiona O'Halloran

Department of Biological Sciences Publications

Group B Streptococcal isolates (n = 235) from the South of Ireland were characterised by serotyping, antimicrobial susceptibility and determination of the phenotypic and genotypic mechanisms of resistance. Resistance to erythromycin and clindamycin was observed in 21·3% and 20·4% of the total population, respectively. The c-MLSB phenotype was the most common phenotype detected (62%), with ermB being the predominant genetic determinant, present in 84% of resistant isolates. The rare L phenotype was observed in 2·9% (n = 7) of isolates, four of which harboured the lsaC gene responsible for clindamycin resistance. Serotypes Ia, III and II were the most common …


Sequence Extension Of The Tryptophan And Shikimate Operons In Clostridium Scatologenes Atcc 25775, Shawn Johnston Smiley Oct 2017

Sequence Extension Of The Tryptophan And Shikimate Operons In Clostridium Scatologenes Atcc 25775, Shawn Johnston Smiley

Masters Theses & Specialist Projects

3-Methylindole and 4-methylphenol are cytotoxic and malodorant compounds derived from tryptophan and tyrosine, respectively. Each is present in swine waste lagoons and contributes to malodorous emissions from agricultural facilities. Clostridium scatologenes ATCC 25775 produces both compounds and serves as a model organism to study their metabolism and function. Through the repeated assembly and annotation of the Clostridium scatologenes genome, we propose a novel pathway for tryptophan degradation and 3-methylindole production by this organism. The genome of Clostridium scatologenes was sequenced, and re-assembled into contigs. Key elements of the tryptophan and shikimate pathways were identified. Contigs containing these elements were extracted …


Comprehensive Assessments Of The Genetic Determinants In Salmonella Typhimurium For Fitness Under Host Stressors: Oxidative Stress And Iron Restriction, Sardar Abdullah Aug 2017

Comprehensive Assessments Of The Genetic Determinants In Salmonella Typhimurium For Fitness Under Host Stressors: Oxidative Stress And Iron Restriction, Sardar Abdullah

Graduate Theses and Dissertations

Salmonella is an intracellular pathogen that infects a wide range of hosts. The infected host utilizes reactive oxygen species (ROS) and iron-restriction to eliminate the pathogen. We used proteogenomics to determine the candidate genes and proteins that have a role in resistance of S. Typhimurium to H2O2. For Tn-seq, a highly saturated Tn5 library was grown in vitro under either 2.5 (H2O2L) or 3.5 mM H2O2 (H2O2H). We identified two sets of overlapping genes that are required for resistance of S. Typhimurium to H2O2L and H2O2H, and the results were validated via phenotypic evaluation of 50 selected mutants. The enriched …


Accumulation And Expression Of Multiple Antibiotic Resistance Genes In Arcobacter Cryaerophilus That Thrives In Sewage, Jess A. Millar, Rahul Raghavan Apr 2017

Accumulation And Expression Of Multiple Antibiotic Resistance Genes In Arcobacter Cryaerophilus That Thrives In Sewage, Jess A. Millar, Rahul Raghavan

Biology Faculty Publications and Presentations

We explored the bacterial diversity of untreated sewage influent samples of a wastewater treatment plant in Tucson, AZ and discovered that Arcobacter cryaerophilus, an emerging human pathogen of animal origin, was the most dominant bacterium. The other highly prevalent bacteria were members of the phyla Bacteroidetes and Firmicutes, which are major constituents of human gut microbiome, indicating that bacteria of human and animal origin intermingle in sewage. By assembling a near-complete genome of A. cryaerophilus, we show that the bacterium has accumulated a large number of antibiotic resistance genes (ARGs) probably enabling it to thrive in the wastewater. We also …