Bacteria Commons^™

S-Layer Increases Predation Ability Of Myxococcus Xanthus

Symposium of Student Scholars

Background: Myxococcus xanthus is a gram-negative soil bacterium that exhibits micro-predatory activities. When starved, M. xanthus produces resistant spores within fruiting bodies for survival. The S-layer is a paracrystalline structure intertwined in many different patterns and is composed of proteins or glycoproteins. A species that produces the S-layer is Aeromonas. A. salmonicida is a strain of Aeromonas that infects fish. A. hydrophila is another pathogenic strain that causes a wide range of human diseases. We investigated the ability of the S-layer to protect Aeromonas from predation by Myxobacteria. Methods: Myxococcus and prey Aeromonas cultures were standardized to a concentration …

Why Should People Use Face Masks In The Time Of Covid? The Jri Position, Jose Bordon, Alex Glynn, Forest W. Arnold

The University of Louisville Journal of Respiratory Infections

No abstract provided.

Refining The Optimal First Treatment For Pediatric Breast Abscesses, Kayla B. Briggs

Research Days

Background: We previously reported treatment and outcomes of children with untreated, not spontaneously draining (UTND) breast abscesses. What has not been well defined however are those with previously treated, not spontaneously draining (PTND) pediatric breast abscesses. In general, a more conservative approach is favored in children with breast abscesses to avoid damage to the developing breast bud.

Objectives/Goal: We sought to determine if care at a pediatric tertiary referral center impacts disease persistence rate.

Methods/Design: Following IRB approval, patientstherapy.

Results: In all, 114 patients met inclusion criteria, 96 in the UTND group and 18 in the PTND group (Figure 1). …

Identification And Characterization Of Butyrate-Producing Species In The Human Gut Microbiome, Grace Maline

Theses/Capstones/Creative Projects

Inflammatory Bowel Diseases (IBD) including ulcerative colitis, indeterminate colitis, and Crohn’s disease are increasingly common conditions that places a high physical and financial burden on individuals and global healthcare systems. Though many treatments exist for these conditions, their unpredictable nature and causation make them difficult to manage across the variety of IBD patients. Additionally, many of these treatments come with undesirable side effects or modes of delivery. Therefore, it is worthwhile to explore the use of Short Chain Fatty Acids (SCFAs) such as butyrate whose affects in the human gut include decreased inflammation and decreased risk of colorectal cancer. As …

Hemin Utilization In Rhizobium Leguminosarum Atcc 14479, John Lusby

Electronic Theses and Dissertations

Rhizobium leguminosarum is a Gram negative, motile, nitrogen-fixing soil bacterium. Due to the scarcity of iron in the soil bacteria have developed a wide range of iron scavenging systems. The two types of iron scavenging systems used are indirect and direct. In-silico analysis of the genome identified a unique direct iron scavenging system the Hmu operon. This system has been identified in other closely related rhizobium species and is believed to be involved in utilizing heme compounds as a sole source of iron. We have attempted to characterize the role of the Hmu operon in iron utilization by monitoring the …

Deciphering The Mechanisms Of Alcaligenes Faecalis’ Inhibition Of Staphylococcus Aureus And Synergism With Antibiotics, Cortlyn Holdren

Undergraduate Honors Theses

Staphylococcus aureus has developed resistance to several antibiotics including vancomycin, which is often used as a “last resort” treatment. There is an ever-increasing need to develop novel antimicrobial treatments to combat S. aureus and other drug resistant bacteria. Microorganisms are most often found in polymicrobial communities where they either exhibit synergistic or antagonistic relationships. Competition between microorganisms can lead to the discovery of new antimicrobial targets as the specific mechanisms of resistance are elucidated. In addition, synergistic treatments are being evaluated for their combined effect and potential to decrease the concentration of drugs needed, and thus the side effects also. …

The Migration Of Carbapenem-Resistant Acinetobacter Baumannii From The Battlefields Of Iraq And Afghanistan To The Healthcare Facilities Of The Veterans Health Administration, Jeffery Rogers

Capstone Experience

Multidrug-resistant organisms (MDRO) pose a great threat to health across the globe. That threat is also felt in the Veterans Health Administration (VHA). Wounded warriors returning home from the battlefields of Iraq and Afghanistan may have brought with them MDROs, such as the bacterium Acinetobacter baumannii, as they have transitioned from military service into the VHA facilities. This study investigates the interconnectedness of military service in the Department of Defense (DoD) and a lifetime of care at VHA through a longitudinal tracking of a linked cohort of combat veterans with battlefield injuries and subsequent MDR infections of A. baumannii. …

Experimental Evolution And Local Adaptation In Pseudomonas Fluorescens, Alexander England

Honors Theses

Local adaptation occurs in populations when multiple subsets of the same population are exposed to different environmental conditions causing the beneficial evolution of each species in its respective environment (Delph 2018). PURPOSE: Using Pseudomonas fluorescens as a model organism, this project sought to understand how an individual’s relative fitness will be affected after undergoing local adaptation in three different environments. METHODOLOGY: To conduct this experiment, three identical strains of SBW25 and three identical strains of lacZ were grown up in three separate environments. Each environment contained an M9 minimal salt media supplemented with either dextrose, xylose, or a 50/50 mixture …

Microbiological Study In A Gneissic Cave From Sri Lanka, With Special Focus On Potential Antimicrobial Activities, Ethige Isuru P. Silva, Pathmakumara Jayasingha, Saman Senanayake, Anura Dandeniya, Dona Helani Munasinghe

International Journal of Speleology

The emergence of antibiotic resistance is a global health crisis, thus the search for novel antimicrobial compounds has become a continuous necessity. Underexplored and extreme environments, such as cave ecosystems, have been identified as a promising potential source for the discovery of novel microorganisms with novel antimicrobial compounds (AMC). This study presents the first cave microbiological investigation in Sri Lanka, with a special preference for bioprospecting of novel AMC. The cave sediment characterization demonstrated the presence of close to strong acidic conditions (pH 3.1 – 3.3) and thus indicates the possibility of isolating acidophilic microorganisms. Eight cave wall/ceiling fungal strains …

When The Pandemic Opts For The Lockdown: Secretion System Evolution In The Cholera Bacterium, Francis J. Santoriello, Stefan Pukatzki

Publications and Research

Vibrio cholerae, the causative agent of the diarrheal disease cholera, is a microbe capable of inhabiting two different ecosystems: chitinous surfaces in brackish, estuarine waters and the epithelial lining of the human gastrointestinal tract. V. cholerae defends against competitive microorganisms with a contact-dependent, contractile killing machine called the type VI secretion system (T6SS) in each of these niches. The T6SS resembles an inverted T4 bacteriophage tail and is used to deliver toxic effector proteins into neighboring cells. Pandemic strains of V. cholerae encode a unique set of T6SS effector proteins, which may play a role in pathogenesis or pandemic …

Sociodemographic, Clinical Characteristics, And Outcomes Of Influenza Pneumonia Patients Admitted In A Tertiary Care Hospital In Karachi, Pakistan: Findings From A Cross-Sectional Study, Fazal Ur Rehman, Muhammad Arslan Ahmed, Kashif Aziz, Mahmooda Jabeen Ashraf, Tazein Amber, Sumera Aziz Ali

Section of Internal Medicine

Objective: To determine the sociodemographic, clinical characteristics, and outcomes of influenza pneumonia patients in tertiary care hospital, Karachi Pakistan.
Study design: A cross-sectional study.
Place and duration of study: The Aga Khan University Hospital Karachi Pakistan from January 2013 to December 2018. Methodology: All adult patients who were older than 18 years and suspected to have viral pneumonia were included in the study. Data were abstracted on 105 patients and were entered on preformed proforma after reviewing the files of patients.
Results: Ninety-four (89.5%) patients were influenza positive and 15.2% (n=16) had been vaccinated. Around 92.4% (n=97), 81.9% (n=86) and …

Streptococcus Cristatus – An Oral Bacterium Causing A Case Of Mild Bacteremia And “Possible Endocarditis”, Camilo Guzman, Adi Zaclli, John Molinari

Medical Student Research Symposium

Streptococcus cristatus is a member of the Mitis streptococcus group. Like other members of this group, it resides in mucosal surfaces of the oral cavity but rarely causes disease. We present a case of S. cristatus bacteremia and “possible endocarditis” (per the modified Duke criteria) in a 59-year-old male suffering from end- stage cryptogenic cirrhosis. To date, it is the fifth reported case of disease caused by the microbe, and the first adult case in which S. cristatus was the sole microbe identified. Our patient had a history of dental caries and poor dentition, which were likely the source of …

Characterizing The Physiology And Genetics Of Contact Dependent Growth Inhibiton Systems In Burkholderia Species, Alice Elizabeth Oates

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

Contact-dependent growth inhibition (CDI) systems mediate interbacterial competition. The genes encoding these systems are widespread among Gram-negative bacteria, including Burkholderia pathogens. CDI systems of Burkholderia species are composed of two-partner secretion pathway proteins and function to deliver the toxic C-terminus of a polymorphic surface-exposed exoprotein BcpA (Burkholderia CDI protein A) to the cytoplasm of neighboring recipient bacteria upon cell-cell contact. Specific outer and inner membrane proteins facilitate BcpA translocation both out of the donor bacterium and into the recipient cell cytoplasm. Most Burkholderia species-specific CDI translocation factors in recipient cells are unknown. BcpA intoxication functions as a mechanism by …

Covid-19 Presenting With Spontaneous Pneumothorax, Intisar Ahmed, Hunaina Shahab, Muhammad Arslan Ahmed, Muhammad Sohaib

Section of Cardiology

The coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The disease mainly affects respiratory system. Its common clinical findings include fever, cough and shortness of breath. Characteristic radiological features of the disease include peripherally distributed, bilateral ground-glass opacities, predominantly involving the lower lung zones. In this report, we present a case of COVID-19 disease presenting with spontaneous pneumothorax. A 26-year male patient was admitted to the Emergency Department with fever, dry cough, shortness of breath and right-sided chest pain. Radiographic imaging of the patient revealed pneumothorax on the right and peripherally distributed non-homogenous opacification. …

Dendrimer-Based Antibiotics For The Treatment Of Bacterial Biofilm In Cystic Fibrosis (Cf), Younan Ma

Theses and Dissertations

Pseudomonas aeruginosa (PA) is the predominant pathogen in chronic lung infections of cystic fibrosis (CF) patients. The most important mechanism of adaptation of PA to host defense and antibiotic treatment is the formation of biofilms within the mucus layer covering the lung bronchi. The effectiveness of antibiotics such as aminoglycosides is significantly attenuated by their limited penetration through thick mucus and embedded biofilm matrix in patients’ lung. Inhaled tobramycin (Tobra), which is the most commonly used antibiotics in the treatment of PA infections for CF patients, is usually found to be in very high concentration in patients’ lung, and yet …

Bacterial Association Networks From Healthy And Cancer-Associated Gut Microbiomes, Mark Loftus

Electronic Theses and Dissertations, 2020-

The human gastrointestinal tract is colonized by a diverse community of symbiotic microorganisms, mainly bacteria, that are known to play essential roles in maintaining the health of their human host. Disruption of this bacterial community has been associated with numerous diseases, including Colorectal Cancer (CRC). CRC is one of the leading causes of cancer-related deaths worldwide. As such, focus has been placed on the modulation of the bacterial community within the cancer-associated gut microbiome as the next step in possible CRC treatment and prevention strategies. To use the bacterial community for these purposes, a better understanding of the associations that …

Utilizing The Coughing Rat Model Of Pertussis To Improve Vaccine Efficacy, Jesse M. Hall

Graduate Theses, Dissertations, and Problem Reports

Pertussis, also known as whooping cough, is a respiratory disease caused by the highly contagious, Gram-negative pathogen Bordetella pertussis (Bp). Infection occurs through inhalation of aerosolized droplets containing Bp, which then colonizes ciliated epithelial cells of the respiratory tract. Here, Bp expresses toxins and virulence factors that lead to leukocyte recruitment, paroxysmal cough, and impairment of host innate responses. Currently, in developed countries, acellular pertussis vaccines (aP; DTaP; Tdap) are used to prevent Bp infection and whooping cough disease. However, we currently realize that the aP vaccine efficacy quickly wanes resulting in a reemergence of pertussis. Recent …

Advancing Cyanobacteria Biomass Estimation From Hyperspectral Observations: Demonstrations With Hico And Prisma Imagery, Ryan E. O'Shea, Nima Pahlevan, Brandon Smith, Mariano Bresciani, Todd Egerton, Claudia Giardino, Lin Li, Tim Moore, Antonio Ruiz-Verdu, Steve Ruberg, Stefan G.H. Simis, Richard Stumpf, Diana Vaičiūtė

Biological Sciences Faculty Publications

Retrieval of the phycocyanin concentration (PC), a characteristic pigment of, and proxy for, cyanobacteria biomass, from hyperspectral satellite remote sensing measurements is challenging due to uncertainties in the remote sensing reflectance (∆R_rs) resulting from atmospheric correction and instrument radiometric noise. Although several individual algorithms have been proven to capture local variations in cyanobacteria biomass in specific regions, their performance has not been assessed on hyperspectral images from satellite sensors. Our work leverages a machine-learning model, Mixture Density Networks (MDNs), trained on a large (N = 939) dataset of collocated in situ chlorophyll-a concentrations (Chla), …

A Microbiome Analysis Of The Relationship Among Crayfish Ectosymbionts And Their Environment, John Hoverson

Senior Honors Theses

The purpose of this project was to determine if there are differences present between the α-diversities of the crayfish microbiome and its surrounding water and sediment. Furthermore, this project sought to discover if these differences hold when microbiomes are evaluated between crayfish of first and second stream orders. Finally, this project sought to determine if the presence of branchiobdellidan ectosymbionts on the crayfish caused further differences in the crayfish microbiome. While the hypothesized patterns between crayfish, ectosymbionts, and stream order were not found to exist, a significantly different microbiome was observed between water, sediment, and crayfish, and the α-diversity of …

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 …