Microbiology Commons^™

Efforts To Improve Diagnosis Of Bacteraemia By Reducing Blood Culture Contamination In An Emergency Department: Strategies And Outcome, Najma Shaheen, Mohammad Zeeshan, Naima Fasih, Joveria Farooqi, Kausar Jabeen, Seema Irfan

Department of Pathology and Laboratory Medicine

Objective: To assess the strategies and outcome for reducing blood culture contamination in order to improve the diagnosis of bacteraemia.
Methods: The interventional study was conducted at a tertiary care hospital in Karachi from January 1, 2013, to December 31, 2016. The blood culture contamination data related to the first year of the study was taken as the baseline pre-intervention data. Strategies were planned as intervention for improvement by consolidating training and education in the form of dedicated lectures, practising on mannequins and developing in-house video, replacing povidone with 2% chlorhexidine preparation spray plus 70% isopropyl alcohol swabs and inducting …

Characterization Of Microbial Communities Across Disease States And Environmental Conditions In Kemp’S Ridley (Lepidochelys Kempii) And Green Sea Turtles (Chelonia Mydas), Kerry L. Mcnally

Graduate Doctoral Dissertations

All species of sea turtles are threatened or endangered, with various diseases and conditions affecting populations around the world. Understanding healthy populations as well as populations beset by disease conditions, such as fibropapillomatosis and cold-stunning, could lead to helpful tools in the conservation management and medical treatment needed to protect these species. Microbial communities, or the microbiome, at different body sites of sea turtles likely play important roles in the health of these animals, from aiding in digestion to immune system regulation. Disruption of these communities, either through disease and/or environmental factors, may play a role in disease processes and …

Oral Localization Of Scardovia Wiggsiae, Graydon Ramos Carr

UNLV Theses, Dissertations, Professional Papers, and Capstones

Early childhood caries is one of the most prevalent diseases in the United States among children. The formation of caries is a complex, multifactorial process that is still being studied. Researchers have thought for years that Streptococcus mutans was the primary causative agent of early childhood caries. The recent discovery of a novel cariogenic pathogen, Scardovia wiggsiae and its significant contribution to the etiology of early childhood caries has led oral health researchers to re-evaluate this microorganism and its link to this disease. While there have been several projects undertaken within the University of Nevada, Las Vegas School of Dental …

The Influence Of G4 Dna Structures On Stationary Phase Mutagenesis In Bacillus Subtilis, Tatiana Ermi

UNLV Theses, Dissertations, Professional Papers, and Capstones

Until the late 1980’s it was widely understood that bacterial variance emerges randomly during growth. Research that followed has convincingly shown evidence for mutations arising in non-growing conditions, a phenomenon known as stationary-phase mutagenesis. In Bacillus subtilis, an elegant mutagenic mechanism has been elucidated in non-growing cells that biases mutations to transcribed regions of a subpopulation. One interesting possibility is that mutations can be further biased to hotspots within genes through alternate DNA structures known as non-B DNA. Non-B DNA have been linked to genomic instability and disease in humans, lesser is known about its role in bacteria. Here we …

The Significance Of Mfd And Oxidative Damage In Stationary-Phase Mutagenesis In Bacillus Subtilis, Holly Anne Martin

UNLV Theses, Dissertations, Professional Papers, and Capstones

The process of stationary-phase mutagenesis, also known as adaptative or stress-induced mutagenesis, is a phenomenon where bacterial cells accumulate mutations in non-replicative conditions. This process has mainly been studied in Escherichia coli and Bacillus subtilis; however, the underlying mechanisms found in each of these systems differ. Here, I use B.msubtilis to study previously understudied aspects of stationary-phase mutagenesis. In this dissertation, I describe work that has led to three major discoveries which are described below.

First in B. subtilis, Mfd is important for stationary-phase mutagenesis and its mutagenic function at regions of the genome that are transcriptionally upregulated has been …

Identification Of Genome-Linked Bacillus Bacteriophage Proteins, Katherine Dyer

Honors Program Theses

Small viruses that can infect bacteria, called bacteriophages, can be found in the soil. These viruses are being examined as a potential treatment against bacterial infections when antibiotics are not available or non-effective. Before viruses can be used as a medical treatment, they must be studied extensively. Previous attempts to sequence the terminal end of the genome of a bacteriophage QCM-11 (Quartz-Crystal-Microbalance-11: Q11) resulted in error. It is thought that a covalently bound protein may be attached to Q11’s DNA, blocking sequencing of the genome from the 5’ end. Proteins bound to the DNA of phages is not unheard of, …

Rapid Detection Of Toxin-Producing Cyanobacteria, Timothy Alba

UNLV Theses, Dissertations, Professional Papers, and Capstones

Lake Mead provides drinking water to millions of people in Nevada, California, and Arizona. In 2015, the Southern Nevada Water Authority detected the cyanobacteria-produced toxin microcystin in the lake for the very first time. This toxin is lethal in large doses, and in small doses it causes a myriad of serious health effects. Detecting microcystin directly is a time-consuming and expensive process that requires liquid chromatography tandem mass spectrometry or immunological analyses, which require a full day or more to process samples. In order to provide water managers with the methodology for a toxin monitoring plan, this work developed a …

Zika Virus Induces Apoptosis In Retinal Pigmented Epithelial Cells, Madison Kraus, Philma Glora Muthuraj, Sathish Kumar Natarajan

UCARE: Research Products

Zika virus is a single-stranded positive sense RNA virus that attracted international attention in 2015 when an epidemic broke out in Brazil. This vector borne virus is transmitted by mosquitos and is especially concerning for pregnant women because the virus can affect the development of the fetus. One known complication is the destruction of infected retinal epithelial cells. The transduction of light is interrupted due to cell death and results in blind spots. Previous research has demonstrated that palmitoleate can reduce the observed levels of apoptosis in ZIKAV infected JEG-3 cells. We have also seen the protection of retinal pigmented …

Antimicrobial Activity Of Extracts From The Leaves Of Marrubium Vulgare, Ashley Cravens

Undergraduate Theses

Natural products have served as powerful therapeutics against pathogenic bacteria since the golden age of antibiotics of the mid-20th century. In the United States, antibiotics are a key component of modern medicine and are one of the top written prescriptions every year. However, overuse and misuse of antibiotics has led to an increasing frequency of antibiotic-resistant infections. These infections are difficult and expensive to treat, often resulting in increased length of illness, hospital stays, and mortality rates. This demonstrates a clear need for novel antibiotics in for modern medicine. Murrubium vulgare (white horehound) is a shrub found in the Appalachia …

Effect Of Zinc On Microcystis Aeruginosa And Its Toxin Production, Jose L. Perez

Seton Hall University Dissertations and Theses (ETDs)

Cyanobacteria harmful algal blooms (CHABs) are globally increasing biomasses of detrimental cyanobacteria due to anthropogenic water phosphorous and nitrogen loading and climate change. CHABs often produce secondary metabolites, cyanotoxins, that cause harmful effects to organisms, most water systems, and socioeconomic infrastructures. Additionally, the presence of heavy metal pollutant runoff in CHAB affected environments may result in CHAB population changes – aggravating toxigenicity. Zinc metal resistance and stress response were studied in microcystin (MC) cyanotoxin-producing Microcystis aeruginosa UTEX LB 2385 (M. aeruginosa UTEX LB 2385) and non-MC producing Microcystis aeruginosa UTEX LB 2386 (M. aeruginosa UTEX LB 2386) cyanobacteria. Molecular analysis …

Research Tools And Their Uses For Determining The Thermal Inactivation Kinetics Of Salmonella In Low-Moisture Foods, Soon Kiat Lau

Department of Food Science and Technology: Dissertations, Theses, and Student Research

The reputation of low-moisture foods as safe foods has been crumbling over the past decade due to repeated involvement in foodborne illness outbreaks. Although various pasteurization technologies exist, a majority are thermal processes and have not been well-characterized for pasteurizing low-moisture foods. In addition, the nature of a low-moisture food matrix introduces various experimental complications that are not encountered in high-moisture foods. In this dissertation, the development, building instructions, and characterization of various open source tools for studying the inactivation kinetics of microorganisms in low-moisture foods are described. The first tool is the TDT Sandwich, a dry heating device for …

Determining Ideal Swab Type For Collection Of The Microbiome For Forensic Identification Purposes, Natalie M. Wise

Honors Projects

In recent years, forensic scientists have begun looking at the microbiome as a new possible human identification method. The microbiome is made up of all the microorganisms living on or in the human body.¹ It is believed that it may be possible to use the microbiome as a unique identifier, to link cohabitating individuals, or even to connect a person with a specific location. In order to study the microbiome, we must first be able to successfully collect it, and then, release it from that collection tool for examination. This may sound simple, but this area of research is …

The Efficacy Of Hand Washing And Cleaning And Disinfecting Methods, Christina J. Amoruso

Virtual 2020 Spring Student Showcase for Research and Creative Inquiry

Potentially pathogenic microorganisms are often used in teaching laboratories. Several different cleaning methods are available and implemented in these laboratories. This project was originally aimed to determine the most efficient method of cleaning lab surfaces and student hands. The topic of this investigation became even more relevant due to the recent development with the COVID-19 pandemic. Efficient hand washing and cleaning methods are more important now than ever. The purpose of hand washing is to reduce the number of microorganisms from the hands (Michaels, 2002). Proper hand washing with friction and soap is necessary to decontaminate hands (Miller, 2011).

Evolutionary Bioethics Advanced By Ernest Everett Just: Implications For Biology, Ethics, And Theology, Theodore Walker

Perkins Faculty Research and Special Events

Ernest Everett Just (1883-1941) is an acknowledged “pioneer” in biology, being honored with a Black Heritage postage stamp in 1996. Here we discover that Just also made pioneering contributions to general evolutionary bioethics (distinct from special medical bioethics) by advancing a cell-biology-rooted theory of the origin and continuing evolution of ethical behavior influenced by the “law of environmental dependence.”

See especially “The Origin of Man’s Ethical Behavior (1941, unpublished book manuscript) by Ernest Everett Just and Hedwig Schnetzler Just, discovered in 2018 among the collected papers of E.E. Just at the Moorland-Spingarn Research Center at Howard University.

Accordingly, evolution is …

Insight On Thermal Stability Of Magnetite Magnetosomes: Implications For The Fossil Record And Biotechnology, Jefferson Cypriano, Mounib Bahri, Kassioge Dembele, Walid Baaziz, Pedro Leao, Dennis A. Bazylinski, Fernanda Abreu, Ovidiu Ersen, Marcos Farina, Jacques Werckmann

Life Sciences Faculty Research

Magnetosomes are intracellular magnetic nanocrystals composed of magnetite (Fe3O4) or greigite (Fe3S4), enveloped by a lipid bilayer membrane, produced by magnetotactic bacteria. Because of the stability of these structures in certain environments after cell death and lysis, magnetosome magnetite crystals contribute to the magnetization of sediments as well as providing a fossil record of ancient microbial ecosystems. The persistence or changes of the chemical and magnetic features of magnetosomes under certain conditions in different environments are important factors in biotechnology and paleomagnetism. Here we evaluated the thermal stability of magnetosomes in a temperature range between 150 and 500 °C subjected …

Go With Your Gut: The Role Of Gut Microbiota In Health, Lydia Bangerter, Mateja R. Savoie-Roskos, Jeffrey Chapman, Abbigail Sundell, Carrie Durward

All Current Publications

Living within your gastrointestinal tract (gut) are about 100 trillion bacterial cells—your gastrointestinal microbiota—a host of bacteria that play a vital role in your body (Ghaisas, Maher, & Kanthasamy, 2016). Your gut microbiome is responsible for a wide variety of functions that contribute to overall health and may be linked to many chronic diseases including cancer, obesity, and cardiovascular disease (Ghaisaset al., 2016; Peregrin, 2013). This fact sheet will discuss the role the gut microbiome plays in various aspects of health and how to improve your gut health.

The Role Of Conformational Dynamics In Isocyanide Hydratase Catalysis, Medhanjali Dasgupta

Department of Biochemistry: Dissertations, Theses, and Student Research

Post-translational modification of cysteine residues can regulate protein function and is essential for catalysis by cysteine-dependent enzymes. Covalent modifications neutralize charge on the reactive cysteine thiolate anion and thus alter the active site electrostatic environment. Although a vast number of enzymes rely on cysteine modification for function, precisely how altered structural and electrostatic states of cysteine affect protein dynamics, which in turn, affects catalysis, remains poorly understood.

Here we use X-ray crystallography, computer simulations, site directed mutagenesis and enzyme kinetics to characterize how covalent modification of the active site cysteine residue in the enzyme, isocyanide hydratase (ICH), affects the protein …

Comment: Probably A Good News: Covid-19 Is Not Spreading Fast In Tropical Region Like In Temperate Region, Madeeha Manzoor

Journal of Bioresource Management

My understanding of Covid-19 is that, there are some climatic factors involved in seed spread of this virus. As it started from the area of China which falls under temperate zone, its second victim was Iran’s city Qom which also falls under temperate zone and third is Italy which is completely in temperate zone.

Data from two countries from Temperate zone and three countries from Tropical zone was compared. The days counted from the 100 cases each country reached as day one and further days studied on equal basis.

Investigation Of An Elevational Gradient Reveals Strong Differences Between Bacterial And Eukaryotic Communities Coinhabiting Nepenthes Phytotelmata, Kadeem J. Gilbert, Leonora S. Bittleston, Mark Arcebal K. Naive, Anthony E. Kiszewski, Perry Archival C. Buenavente, David J. Lohman, Naomi E. Pierce

Publications and Research

Elevation is an important determinant of ecological community composition. It integrates several abiotic features and leads to strong, repeatable patterns of community structure, including changes in the abundance and richness of numerous taxa. However, the influence of elevational gradients on microbes is understudied relative to plants and animals. To compare the influence of elevation on multiple taxa simultaneously, we sampled phytotelm communities within a tropical pitcher plant (Nepenthes mindanaoensis) along a gradient from 400 to 1200 m a.s.l. We use a combination of metabarcoding and physical counts to assess diversity and richness of bacteria, micro-eukaryotes, and arthropods, and compare the …

Mechanisms Of Silencing Suppression By A Polerovirus P0 Protein, Natalie Holste, Hernan Garcia-Ruiz

School of Biological Sciences: Presentations

Maize lethal necrosis is an intense viral disease spreading across sub-Saharan Africa. Maize is the staple crop grown in sub-Saharan Africa, but most crops infected with maize lethal necrosis will not survive to harvest. This causes immense economic hardship and starvation within the population. Maize lethal necrosis consists of a combination of two viruses, Maize chlorotic mottle virus (MCMV) and a virus from the genus potyvirus. In a recent study, a Maize yellow dwarf virus-RMV (MYDV-RMV)-like polerovirus, was repeatedly detected in plants with maize lethal necrosis. Poleroviruses have a silencing suppressor, P0 protein, and the mechanism of suppression is poorly …