Bacteriology Commons^™

Lack Of Inflammatory Response In Mouse Embryonic Cells To Listeria Infection, Damilola Oyebode

Master's Theses

Approximately 1 in 5 pregnancies in the United States results in miscarriage, with a significant percentage of these losses attributed to failed implantation due to immunological challenges encountered by the early embryo. Recent research has shown that key cell types within mouse blastocysts, including embryonic stem cells (ESCs) and trophoblast stem cells (TSCs), exhibit remarkable resilience against the cytotoxic effects associated with viral infections and embryotoxic cytokines, such as TNFα and IFNγ, both of which are known to hinder blastocyst development. However, the immune properties of the preimplantation stage embryo, specifically the blastocyst, remain poorly understood. Using mouse cell model, …

Limits Of Longwood's Electron Microscope: A Study In Biological Imaging, Rachel Danzitz, Bjoern Ch. Ludwar

Fall Showcase for Research and Creative Inquiry

This study evaluates the imaging capabilities and limitations of the Hitachi TM4000II Plus Scanning Electron Microscope (SEM) and its Scanning Transmission adapter in biological imaging. A variety of specimens, including protozoans (e.g., Volvox and nematodes), bacteria (e.g., Magnetospirillum gryphiswaldense, Bacillus cereus, and Escherichia coli), tissue samples, and blood, were analyzed. While the SEM effectively imaged protozoans and bacteria, its ability to visualize viruses was deemed impractical. Despite claims of magnification up to 100,000x, clarity significantly decreased beyond 5,000x. The transmission adapter proved functional but challenging to operate consistently. The study highlights the microscope's limitations in producing high-clarity, …

Antibiotic Susceptibility Pattern And Esbl Prevalence In Nosocomial Escherichia Coli From Urinary Tract Infection In Kpk, Peshawar, Muhammad Fawad, Noha E Abdel-Razik, Zain Alhindi, Muhammad Usman Amin, Eman Adnan Abu-Seer, Mashael S.Alfaifi, Murad Ali, Farkad Bantun, Sheraz Dawar, Suleman Khan, Saad Alghamdi

Journal of Bioresource Management

The study aimed to evaluate antibiotic susceptibility patterns and extended-spectrum beta-lactamase prevalence in Escherichia coli isolated from urinary tract infections. Total fifty (50) samples of E. coli were obtained from urinary tract infection specimens in Hayatabad Medical Complex and private clinics in Peshawar, Pakistan. The present study obtained 50 E. coli isolates from 100 UTI specimens. The plates were incubated at 35 to 37°C for 24 to 48 hours. Different biochemical tests were carried out to identify the isolates. Antibiotic susceptibility testing and ESBL screening were done per the CLSI (2023) guidelines. The disc diffusion method was used to determine …

Microbial Colonization Of New Lava Tubes Formed By The Fagradalsfjall Volcano’S Eruption (Iceland), Ettore Lopo, Francesco Sauro, Ana Zelia Miller, Bogdan Petroniu Onac, Martina Cappelletti

FRONTIERS UNBOUND: Exploring Extreme Environments

No abstract provided.

Genomic Analysis Of Enterobacter Species Isolated From Patients In United States Hospitals, Fred C. Tenover, Isabella A. Tickler

Guidelines, Recommendations, and Other Resources on Antimicrobial Resistance

Abstract: We analyzed the whole genome sequences (WGS) and antibiograms of 35 Enterobacter isolates, including E. hormaechei and E. asburiae, and the recently described E. bugandensis, E. kobei, E. ludwigii, and E. roggenkampii species. Isolates were obtained from human blood and urinary tract infections in patients in the United States. Our goal was to understand the genetic diversity of antimicrobial resistance genes and virulence factors among the various species. Thirty-four of 35 isolates contained an AmpC class blaACT allele; however, the E. roggenkampii isolate contained blaMIR-5. Of the six Enterobacter isolates resistant to ertapenem, imipenem, and meropenem, …

Leaf Diseases And Their Management In Oats, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Leaf diseases of oats impact on grain yield and quality and reduce hay quality characteristics, such as colour and digestibility. This page outlines the symptoms, factors favouring disease risk and spread, and management.

Major leaf diseases of oats are septoria avenae blotch, stem rust, leaf rust, and barley yellow dwarf virus. Their severity changes with seasons.

Multidrug-Resistant Esbl-Producing Escherichia Coli Coexisting With Colistin-Resistance Genes In Pig Farms, Central Thailand, Wipawee Songsaeng, Nutthee Am-In, Nuvee Prapasarakul, Wandee Sirichokchatchawan

The Thai Journal of Veterinary Medicine

The presence of extended-spectrum beta-lactamase and colistin resistance E. coli in food-producing animals is a public health concern. This study was conducted using a rigorous methodology to survey the prevalence of ESBL-producing and colistin-resistant E. coli from pig farms in the central part of Thailand. A total of 519 samples were collected from fecal, feed, and waste in 53 farms located in central Thailand. All samples were inoculated onto selective agar, and species identification was performed using biochemical assays and MAlDI-TOF MS. Antimicrobial susceptibility was determined by broth microdilution, and ESBL production was confirmed by the combination disc diffusion method. …

The Molecular Detection Of Hemotropic Mycoplasma Species In Dogs, Hafize Tuğba Yüksel Dolgun, Şükrü Kirkan

The Thai Journal of Veterinary Medicine

Hemotropic mycoplasmas are uncultured bacteria that cause different degrees of hemolytic anemia in infected hosts. Molecular approaches are used to diagnose hemotropic mycoplasmas since they are difficult to identify using conventional methods. The aim of this study was to use molecular approaches to determine hemotropic mycoplasmas in dogs. Blood samples were collected in tubes (with EDTA) from 100 dogs. After DNA extraction, 100 DNA samples were investigated by PCR. Hemotropic mycoplasma was detected in 12 (12%) samples and positive samples were subjected to Sanger sequencing. Mycoplasma haemocanis was detected in 6 (50.0%) of the samples, Candidatus Mycoplasma hematoparvum in 5 …

Pilz Domain-Containing Proteins Regulate Motility In Acinetobacter Baumannii, Gabriel Smith

Electronic Theses and Dissertations

Acinetobacter baumannii is an increasingly multidrug-resistant pathogen contributing to hospital-acquired infections, necessitating a greater understanding of how it interacts with its surroundings. Many bacteria utilize different methods of bacterial motility to move about and interact with these surroundings. A bacterial second messenger, cyclic diguanosine monophosphate (c-di-GMP), can regulate various motility factors that are potentially advantageous for survival in and adaptation to their environment. Concentrations of c-di-GMP are regulated by specific synthesizing and degrading enzymes. Controlled levels of c-di-GMP allow interaction between the c-di-GMP and its binding effectors that induce changes in bacterial phenotypes such as biofilm formation and motility. A …

Host-Microbiome Interactions In The Teleost Brain, Amir Mani Varnoosfaderani

Biology ETDs

This dissertation investigates host-microbial interactions within the teleost brain, previously considered sterile. Reviewing current literature highlights significant gaps in understanding teleost brain immunity, despite prevalent neurotropic diseases. We mapped the immune profiles of rainbow trout brains and meninges, revealing the olfactory bulbs as the immune effector part of the brain and the optic tectum as a nod2 expression hub. High il6 and il10 levels were noted in the telencephalon. A persistent bacterial community within healthy salmonid brains shares diversity with gut and blood microbiota. Brain bacterial isolates exhibit genomic signatures for brain colonization and polyamine biosynthesis. The microbiota shifts across …

Degradation Of Chlorpyrifos Residue On Tropical Inceptisol Soil With Indigenous Bacteria Treatment, Asep Kurnia, Hidayatuz Zu`Amah, Baiq Nunung Sulastri, Ria Fauriah Makmur

Makara Journal of Science

The use of soil microbes is one of the most effective methods for degrading pesticide residue in soil. Microbes can accelerate the degradation of persistent pollutants including chlorpyrifos in soil. This research aims to find soil bacteria with the greatest potential to degrade chlorpyrifos residue in tropical inceptisol soil and determine its degradation index (DI). The soil used in this experiment was collected from agricultural fields in the districts of Demak, Central Java Province, Indonesia. The experiment was performed using factorial randomize complete block design composed of two factors and four replications. The first factors were made up of two …

Fleq And Gac/Rsm-Mediated Regulation Of Biofilm Formation And Swarming Motility In Pseudomonas Fluorescens, Alexander Benito Pastora

Dartmouth College Ph.D Dissertations

Pseudomonas fluorescens is a gram-negative Gammaproteobacterium that survives and persists in diverse environments. This survivability is dependent on the bacterium’s ability to form a biofilm. Within Pseudomonas fluorescens, biofilm formation is a complex and dynamic process involving multiple protein- and polysaccharide-based components which each individually serve a specific purpose. Of these components, the repeats-in-toxin (RTX) adhesins LapA and MapA are critical for biofilm formation. Specifically, LapA is important for initial establishment of a biofilm and MapA is important in forming a fully mature biofilm. Deployment of the RTX adhesins during biofilm formation is a highly coordinated process involving multiple …

Lmpact Of Salmonella Enterica Effector Proteins On Plant Physiology And Immunity, Sara Qader

Honors Theses

Salmonella enterica serovar Typhimurium are primarily recognized as pathogens associated with foodborne illnesses in humans. Salmonella also can colonize plant tissue effectively. The pathogen relies on type III secretion systems (T3SS) to infect mammals and plants successfully and counteract the immune response. Understanding the molecular mechanisms underlying Salmonella’s interactions with plants is essential for developing effective strategies to reduce its impact on human health and agriculture. Effector proteins, known for their role in modulating host-pathogen interactions, have been implicated in the virulence and pathogenicity of Salmonella. However, their specific functions and contributions to Salmonella’s interactions with plants remain largely unknown. …

Impact Of Salmonella Enterica On Plant Physiology And Immunity, Sara Qader

Poster Presentations

Salmonella can colonize plant tissue effectively. Understanding the molecular mechanisms underlying Salmonella’s interactions with plants is essential for developing effective strategies to reduce its impact on human health and agriculture. Effector proteins, known for their role in modulating host-pathogen interactions, have been implicated in the virulence and pathogenicity of Salmonella. However, their specific functions and contributions to Salmonella’s interactions with plants remain largely unknown. Here, we aim to investigate the functions of Salmonella effector proteins during the colonization of plants.

The Physiological Significance Of Nitric Oxide Synthase In Staphylococci, Ryan M. Singh

Theses & Dissertations

Staphylococci, particularly Staphylococcus epidermidis, are common causes of implant-associated infections that may result in notable morbidity and mortality. One of the ways the innate immune system attempts to combat these invading pathogens is via the respiratory burst, in which free radical species such as nitric oxide (NO^•), toxic to bacterial respiration, are released in large quantities. Despite the toxicity of NO^•, some bacteria, including staphylococci, encode an endogenous bacterial nitric oxide synthase (bNOS), whose physiological role has been unclear until now. In this dissertation, we demonstrate that S. epidermidis is able to overcome the toxicity …

Fiddler Crab Gut Microbiomes As An Indicator For Eutrophication Due To Waste-Water Contamination In Estuaries, Madison L. Geraci

Honors Theses

Estuaries are unique biogeochemical zones in coastal systems that provide a myriad of ecological functions: providing habitat for critically important fishery species, diverse species of plants and animals, and contributing to nutrient cycling. Estuaries are vulnerable to anthropogenic stressors as they are intersections between marine and terrestrial communities and are often the hotspot of coastal development and activity. Estuarine sediments act as repositories for anthropogenic contaminants, including excess nutrient runoffs and waste-water pollution that can cause states of eutrophication. Microorganisms are sensitive to these environmental changes, presenting a unique opportunity of being useful bioindicators of environmental stress. Isolating microorganisms from …

Analysis Of Antibiotic Sensitivity Patterns In Pasteurellaceae Family Isolates: A Microbial And Molecular Investigation, Jillian Barron

Honors Scholar Theses

Bacteria in the Pasteurellaceae family are known to cause disease in both human and animal species. Like all species of bacteria, the pathogens in the Pasteurellaceae family evolve and acquire antimicrobial-resistant traits. Antimicrobial resistance of bacteria is a significant public health concern, as treatment of resistant pathogens becomes more difficult, if not impossible, with current medical capabilities. In this project, phenotypic and genotypic analyses were performed on Pasteurellaceae family isolates sourced from the Connecticut Veterinary Medical Diagnostic Laboratory. Phenotypic antibiotic sensitivity patterns of each isolate were assessed against a panel of antibiotics through a Kirby-Bauer disk diffusion test. Disk diffusion …

Characterizing The Role Of Pa5189 Of Pseudomonas Aeruginosa In Deletion And Overexpression Mutants, Seh Na Mellick

Theses/Capstones/Creative Projects

In the context of rising multidrug resistance in biofilm-forming pathogens like Pseudomonas aeruginosa, this study investigates the role of the understudied transcription factor PA5189 in antibiotic resistance and biofilm formation. PA5189 deletion and overexpression mutants were created in a parent P. aeruginosa strain using pEX18Tc-based recombinant suicide vectors, with genotypic verification of putative triparental conjugants achieved through restriction digestion and PCR. The study revealed that PA5189 overexpression significantly increases resistance to commonly used broad spectrum antibiotics such as ciprofloxacin and imipenem. Additionally, differential expression of PA5189 was found to notably affect biofilm formation, with variations contingent on the nutrient …

Inactivation Of Escherichia Coli, Salmonella Enterica, And Listeria Monocytogenes Using The Contamination Sanitization Inspection And Disinfection (Csi-D) Device, Jennifer Mccoy Sanders, Vanessa Alarcon, Grace Marquis, Amanda Tabb, Jo Ann Van Kessel, Jakeitha Sonnier, Brad J. Haley, Insuck Baek, Jianwei Qin, Moon Kim, Fartash Vasefi, Stanislav Sokolov, Rosalee S. Hellberg

Food Science Faculty Articles and Research

The Contamination Sanitization Inspection and Disinfection (CSI-D) device is a handheld fluorescence-based imaging system designed to disinfect food contact surfaces using ultraviolet-C (UVC) illumination. This study aimed to determine the optimal CSI-D parameters (i.e., UVC exposure time and intensity) for the inactivation of the following foodborne bacteria plated on non-selective media: generic Escherichia coli (indicator organism) and the pathogens enterohemorrhagic E. coli, enterotoxigenic E. coli, Salmonella enterica, and Listeria monocytogenes. Each bacterial strain was spread-plated on non-selective agar and exposed to high-intensity (10 mW/cm²) or low-intensity (5 mW/cm²) UVC for 1–5 s. Control …

Antimicrobial Activity Of Cat Flea (Ctenocephalides Felis) Gut Proteins On Different Days After Blood Feeding, Dhruva K. Karnik

Honors College Theses

Cat fleas (Ctenocephalides felis) are a blood-feeding ectoparasitic insect and a common domestic pest found throughout the world. Because of their reliance on host blood, fleas are exposed to blood-borne pathogens; however, the flea gut lumen is a hostile environment for microbial colonization. For example, the gut epithelia differentially express immune genes in response to feeding. In the present study, we measured the antimicrobial activity of gut proteins from cat fleas at different days after feeding (2, 5, 7, and 14). Dissected flea guts were homogenized, passed through a syringe filter, and measured in a protein assay kit. …