Oral Biology and Oral Pathology Commons^™

Oral Pathogens Reprogram Endothelial Barrier And Angiotensin-Converting Enzyme2/Endothelial Nitric Oxide Synthase-Nitric Oxide Signaling To Promote Blood Pressure Dysregulation, Ming-Shou Hsieh, Tung-Nien Hsu, Chin-Sheng Huang, Ting-Yi Renn, Kuang-Tai Kuo, Kuo-Yao Lin, Wei Jen Chang

Journal of Dental Sciences

Background/purpose: Although periodontal disease is associated with an increased risk of hypertension, the endothelial mechanisms linking oral inflammation to vascular dysfunction remain unclear. We investigated whether Porphyromonas gingivalis lipopolysaccharide (Pg-LPS) can directly disturb endothelial homeostasis and whether macrophage–endothelial crosstalk further worsens endothelial injury.

Materials and methods: Human umbilical vein endothelial cells (HUVECs) were exposed to Pg-LPS alone or co-cultured (transwell system) with Pg-LPS-primed human monocytic cells -derived macrophages. Endothelial dysfunction was assessed through nitric oxide (NO) production, endothelial nitric oxide synthase (eNOS) phosphorylation, inflammatory and adhesion molecule expression, as well as junctional and cytoskeletal changes. Macrophage …

Molecular Insights Into Antibiofilm Inhibitors Of Streptococcus Mutans Glucosyltransferases Through In Silico Approaches, Lubna Atta, Ali Raza Siddiqui, Mamona Mushtaq, Sajida Munsif, Mohammad Nur-E-Alam, Aftab Ahmad, Zaheer Ul-Haq

Pharmacy Faculty Articles and Research

Streptococcus mutans, a primary cariogenic bacterium, plays a central role in dental caries, one of the most widespread chronic diseases globally. Glucosyltransferases (GTFs) are key virulence factors in this process, as they synthesize extracellular polysaccharides that contribute to biofilm formation and pathogenicity. Targeting GTFs has emerged as a promising strategy for preventing dental caries, with previous studies demonstrating its potential efficacy. This study builds on our prior work by providing detailed molecular insights into the binding modes of previously identified GTF inhibitors. Using computational tools, including density functional theory, molecular docking, and molecular dynamics simulations, we examined the binding …

A Fungal Metabolic Regulator Underlies Infectious Synergism During Candida Albicans-Staphylococcus Aureus Intra-Abdominal Co-Infection, Saikat Paul, Olivia A. Todd, Kara R. Eichelberger, Christine Tkaczyk, Bret R. Sellman, Mairi C. Noverr, James E. Cassat, Paul L. Fidel, Brian M. Peters

School of Dentistry Faculty Publications

Candida albicans and Staphylococcus aureus are two commonly associated pathogens that cause nosocomial infections with high morbidity and mortality. Our prior and current work using a murine model of polymicrobial intra-abdominal infection (IAI) demonstrates that synergistic lethality is driven by Candida-induced upregulation of functional S. aureus α-toxin leading to polymicrobial sepsis and organ damage. In order to determine the candidal effector(s) mediating enhanced virulence, an unbiased screen of C. albicans transcription factor mutants was undertaken revealing that zcf13Δ/Δ fails to drive augmented α-toxin or lethal synergism during co-infection. A combination of transcriptional and phenotypic profiling approaches shows that ZCF13 regulates …

Educating Nurses On Frequent Oral Care For Mechanically Ventilated Patients: An Evidence-Based Practice Project Proposal, Grace Alford, Susan Butz, Ruth Chavez, Joy Shoemaker

Doctor of Nursing Practice Scholarly Projects

The final scholarly project proposal is to implement oral care education for nurses in an intensive care unit (ICU). The proposal aims to create a guideline for an investigator to implement oral care recommendations for mechanically ventilated patients in order to reduce ventilator-associated pneumonia (VAP). The proposal consists of obtaining VAP data and oral care charting data for the unit studied, steps for providing oral care education, and analysis recommendations. Oral care involves swabbing the patient’s mouth every two hours with a swab and mouthwash. Oral care education would include handouts and direct teaching. The proposal aims to increase oral …

Convolutional Neural Network Based Analysis - An Aid To Diagnose Bacterial And Fungal Osteomyelitis, Saiprasad Alva, Dominic Augustine, Sowmya Sv, Mukul Saini, Sanjana Shetty

Annual Research Symposium

Osteomyelitis may be classified as Bacterial (Actinomycotic), Fungal (Mucormycotic), or combined based on the etiological agent. During histopathological examination, there is a high chance that bacterial colonies or fungal hyphae may be missed by the human eye, especially when there is a paucity of organisms. This may lead to a faulty diagnosis of the type of osteomyelitis which along with an improper treatment plan would cause further progression of the disease and various other complications. Therefore, the diagnosis of the exact etiological variant of osteomyelitis is of prime importance to design an appropriate treatment plan. In the present study, bone …

Impaired Neutrophil Extracellular Trap-Forming Capacity Contributes To Susceptibility To Chronic Vaginitis In A Mouse Model Of Vulvovaginal Candidiasis, Junko Yano, Paul L. Fidel

School of Dentistry Faculty Publications

Vulvovaginal candidiasis (VVC), caused by is characterized by aberrant inflammation by polymorphonuclear neutrophils (PMNs) in the vaginal lumen. Data from the established murine model shows that despite potent antifungal properties, PMNs fail to clear due to local heparan sulfate that inhibits the interaction between PMNs and , resulting in chronic vaginal immunopathology. To understand the role of neutrophil extracellular traps (NETs) in defense against at the vaginal mucosa, we investigated the NET-forming capacity of PMNs in chronic VVC-susceptible (CVVC-S/C3H) and -resistant (CVVC-R/CD-1) mouse strains. Immunofluorescence revealed the formation of NETs (release of DNA with PMN-derived antimicrobial proteins) in PMN cocultures …

Candida-Induced Granulocytic Myeloid-Derived Suppressor Cells Are Protective Against Polymicrobial Sepsis, Shannon Esher Righi, Amanda J. Harriett, Elizabeth A. Lilly, Paul L. Fidel Jr., Mairi C. Noverr

School of Dentistry Faculty Publications

Polymicrobial intra-abdominal infections (IAI) can lead to life-threatening sepsis with significant morbidity and mortality, especially when pathogenic fungi are involved. We have employed an established clinically relevant mouse model of fungal/bacterial IAI and shown that immunization with low-virulence Candida species, that is, Candida dubliniensis, can induce responses that protect against sepsis via the suppression of lethal inflammation. This protection is dependent on long-lived Gr-1(+) polymorphonuclear leukocytes that display characteristics consistent with myeloid-derived suppressor cells (MDSCs) and trained innate immunity. Here we aimed to functionally and phenotypically characterize these protective Gr-1(+) leukocytes. Compared to nonimmunized control mice, we observed increased levels …

Clinical Effects Of Lactobacillus Reuteri Probiotic In The Treatment Of Chronic Periodontitis: A Systematic Review Of Randomized Controlled Trials, Josephine Ram, Shilpa Bhandi, Kamran H. Awan, Frank Licari, Shankargouda Patil

Annual Research Symposium

No abstract provided.

Eradication Of Enterococcus Faecalis In Conventional Endodontic Retreatments (A Randomized Clinical Trial), Fadl H. Khaled, Roula S. Abiad, Khaled Abd El Galil, Essam Osman

BAU Journal - Creative Sustainable Development

Enterococcus faecalis is the most common bacteria isolated in conventional endodontic retreatments. Aim: To compare the impact of three irrigation modalities on the elimination of the isolated microbial strains of Enterococcus faecalis. Materials and Methods: Thirty patients requiring conventional endodontic retreatment for one of their mandibular premolars and tested positive for E. faecalis were chosen. Patients were randomly divided into three groups (n=10) according to the irrigation modality to be used; group I: syringe irrigation (NaOCl 2.625%), group II: NaOCl 2.625%+EndoActivator and group III: NaOCl 2.625%+diode laser. Before obturation, samples S2 were collected and PCR analysis was performed to identify …

Comparisons Of Oral, Intestinal, And Pancreatic Bacterial Microbiomes In Patients With Pancreatic Cancer And Other Gastrointestinal Diseases, Mei Chung, Naisi Zhao, Richard Meier, Devin C. Koestler, Guojun Wu, Erika De Castillo, Bruce J. Paster, Kevin Charpentier, Jacques Izard, Karl T. Kelsey, Dominique S. Michaud

Department of Food Science and Technology: Faculty Publications

Background: Oral microbiota is believed to play important roles in systemic diseases, including cancer. Methods: We collected oral samples (tongue, buccal, supragingival, and saliva) and pancreatic tissue or intestinal samples from 52 subjects, and characterized 16S rRNA genes using high-throughput DNA sequencing.

Results: Bray–Curtis plot showed clear separations between bacterial communities in the oral cavity and those in intestinal and pancreatic tissue samples. PERMANOVA tests indicated that bacterial communities from buccal samples were similar to supragingival and saliva samples, and pancreatic duct samples were similar to pancreatic tumor samples, but all other samples were significantly different from each …

The Emerging Oral Pathogen, Filifactor Alocis, Disrupts Neutrophil Functions To Enhance Survival And Dysregulate Inflammation., Irina Miralda Molina

Electronic Theses and Dissertations

Periodontitis is an irreversible, chronic inflammatory disease where pathogenic microbial communities accumulate in the gingival crevice. Advances in culture-independent techniques have facilitated the identification of new bacterial species in periodontal lesions, such as the Gram-positive anaerobe, Filifactor alocis. Neutrophils are a major component of the innate host response, and the outcome of their interaction with F. alocis may be a determinant of oral health status. While neutrophil functions typically protect the host against periodontal disease, oral pathogens have adapted to evade or disarm neutrophil microbicidal functions while promoting mechanisms that drive inflammation, which also provides a source of nutrients …

The Role Of Manganese In Streptococcus Sanguinis, Tanya M. Puccio

Theses and Dissertations

Streptococcus sanguinis is primarily associated with oral health as a commensal bacterium. As an opportunistic pathogen, S. sanguinis is capable of colonizing heart valve vegetations, leading to the disease infective endocarditis. Previous studies from our lab have identified the high-affinity manganese transporter SsaACB as important for endocarditis virulence. The impact that manganese depletion has on S. sanguinis had never been evaluated and a secondary manganese transporter has not been identified. Thus, we employed the use of a fermentor to control large-scale growth over time and depleted manganese in an ΔssaACB mutant using a metal chelator, EDTA. The changes in …

Selenomonas Sputigena: Growth Conditions And Projected Virulence Factors Of An Emerging Oral Pathogen, Kayla A. Keller

Theses and Dissertations

Periodontal diseases are ubiquitous diseases. They can affect people through a chronic infection that happens over a lifetime, but also as an aggressive infection that afflicts the younger population. It not only results in tooth loss and a lower quality of life, but it can also lead to fatal secondary infections like cervical cancer, heart disease, and Alzheimer’s disease. This study looks at Selenomonas sputigena, an emerging oral pathogen, that has been hypothesized to contribute to periodontal disease. It has been linked to fatal septicemia and has been found in increased abundance within the oral biofilm during peak infection. …

Examination Of Strain-Dependent Differences In S. Sanguinis Virulence And Growth, Shannon Baker

Theses and Dissertations

Streptococcus sanguinis, an abundant and benign inhabitant of the oral cavity, is an important etiologic agent of infective endocarditis, particularly in people with pre-disposing cardiac valvular damage. Although commonly isolated from patients with IE, little is known about the factors that make any particular S. sanguinis isolate more virulent than another or, indeed, whether significant differences in virulence exist among isolates. To investigate the virulence of multiple isolates, a variation of the Bar-seq (barcode sequencing) method was employed. A conserved chromosomal site was identified for subsequent insertion of a barcode identifier, unique for each strain. Barcode insertion did not …

Nitrosative Stress Sensing In Porphyromonas Gingivalis: Structure And Function Of The Heme Binding Transcriptional Regulator Hcpr, Benjamin R. Belvin

Theses and Dissertations

Porphyromonas gingivalis, a Gram negative anaerobe implicated in the progression of periodontal disease, is capable of surviving and causing infection despite high levels of reactive nitrogen species found in the oral cavity due to its efficient nitrosative stress response. HcpR is an important sensor-regulator that plays a vital step in the initiation of the nitrosative stress response in many Gram negative anaerobic bacteria. We employ a combination of X-ray crystallography, SAXS, resonance Raman spectroscopy, UV-Vis spectroscopy, and molecular biology techniques to better understand this key regulator. Knockout of the hcpR gene in W83 P. gingivalis results in the inability of …

Identification Of Transcription Factors Gzf3, Rfx1, Orf19.3928 As Being Implicated In Candida-Bacterial Interactions., Joni Watson

Undergraduate Honors Theses

Candida albicans is an opportunistic pathogen that is present in the normal flora in a majority of individuals. One key factor in C. albicans virulence is the ability to change its morphology from yeast to an elongated or hyphal form. The regulation of this morphogenesis relies in part upon quorum sensing (QS) molecules. C. albicans often exists as part of a mixed culture alongside other microbes and is influenced by their presence as well as the presence of QS molecules that they produce. In this study, a library of diploid homozygous transcriptional regulator knockout (TRKO) mutants were screened to identify …

Neisseria Oralis Sp. Nov., Isolated From Healthy Gingival Plaque And Clinical Samples, William J. Wolfgang, Teresa V. Passaretti, Reashma Jose, Jocelyn Cole, An Coorevits, Andrea N. Carpenter, Sherly Jose, Anita Van Landschoot, Jacques Izard, Donna J. Kohlerschmidt, Peter Vandamme, Floyd E. Dewhirst, Mark A. Fisher, Kimberlee A. Musser

Department of Food Science and Technology: Faculty Publications

A polyphasic analysis was undertaken of seven independent isolates of gram-negative cocci collected from pathological clinical samples from New York, Louisiana, Florida, and Illinois and healthy subgingival plaque from a patient in Virginia, USA. The 16S rRNA gene sequence similarity among these isolates was 99.7–100 %, and the closest species with a validly published name was Neisseria lactamica (96.9 % similarity to the type strain). DNA–DNA hybridization confirmed that these isolates are of the same species and are distinct from their nearest phylogenetic neighbor, N. lactamica. Phylogenetic analysis of 16S and 23S rRNA gene sequences indicated that the …

Pathogenicity Of Treponema Denticola Wild-Type And Mutant Strain Tested By An Active Mode Of Periodontal Infection Using Microinjection, Jacques Izard, Hajime Sasaki, Ralph Kent

Department of Food Science and Technology: Faculty Publications

The available passive mode of periodontal infections in mice requires high efficiency of bacterial attachment and invasiveness and is not always suitable to test the pathogenicity of genetically engineered mutant strains. We developed an active mode of oral infection, using microinjection in the marginal gingiva of mice, to test the pathogenicity of a genetically engineered Treponema denticola mutant strain deficient in intermediate-like filaments, compared to the wild-type strain. This targeted mode of infection inoculates the bacterial strain to be tested directly at a lesion site (needle entry point) located at the future periodontal lesion site. The efficiency of T. …

Killing Of Treponema Denticola By Mouse Peritoneal Macrophages, P. Gaibani, C. Vocale, S. Ambretti, F. Cavrini, Jacques Izard, L. Miragliotta, M. T. Pellegrino, V. Sambri

Department of Food Science and Technology: Faculty Publications

Treponema denticola has been identified as an important cause of periodontal disease and hypothesized to be involved in extra-oral infections. The objective of this study was to investigate the role of T. denticola cell length and motility during mouse peritoneal macrophages in vitro uptake. Macrophages, incubated under aerobic and anaerobic conditions, produced a similar amount of TNF-α when stimulated with Escherichia coli LPS. The uptake of FlgE- and CfpA-deficient mutants of T. denticola was significantly increased compared with the wild-type strain, due to cell size or lack of motility. Opsonization with specific antibodies considerably improved the treponemes’ uptake. …

Treponema Denticola In Disseminating Endodontic Infections, F. Foschi, Jacques Izard, H. Sasaki, V. Sambri, C. Prati, R. Müller, P. Stashenko

Department of Food Science and Technology: Faculty Publications

Treponema denticola is a consensus periodontal pathogen that has recently been associated with endodontic pathology. In this study, the effect of mono-infection of the dental pulp with T. denticola and with polymicrobial “red-complex” organisms (RC) (Porphyromonas gingivalis, Tannerella forsythia, and T. denticola) in inducing disseminating infections in wild-type (WT) and severe-combined-immunodeficiency (SCID) mice was analyzed. After 21 days, a high incidence (5/10) of orofacial abscesses was observed in SCID mice mono-infected with T. denticola, whereas abscesses were rare in SCID mice infected with the red-complex organisms or in wild-type mice. Splenomegaly was …

Periradicular Response Of Immunodeficient Rats To Mechanical Pulpal Exposure, James E. Stich

Loma Linda University Electronic Theses, Dissertations & Projects

Periradicular lesions develop as a result of the interaction between root canal irritants and the immune system. The purpose of this study was to investigate the periradicular response of immunodeficient rats to their oral flora. Twenty Sprague-Dawley rats received a total body irradiation dose of 750 cGy one week prior to the investigation. The pulps of the mandibular first molars of these animals and six nonirradiated rats were exposed mechanically with a ½ round bur and left open to the oral cavity. Additional irradiation (350 cGy) was administered bi-weekly to maintain immunosuppression. Periradicular specimens were obtained after two and four …