Land2Lab Project: Reflections on Learning about Mi'kmaw Foodways.

Land2Lab is an evolving community-based intergenerational program that brings together Elders and youth on the land and in the kitchen and lab to share and celebrate Mi'kmaw foodways. Rooted in an Etuaptmumk-Two Eyed Seeing (E-TES) perspective, which acknowledges both Indigenous and Western ways of knowing, the project to date has featured seasonal food workshops, involvement in a children's summer math camp, a food safety training workshop for teens, and the development of an online toolkit. The project was guided by the Mi'kmaw principle of Netukulimk, which reinforces respect for Mother Earth and stewardship of the land, water, and air for subsequent generations. Involvement of community leaders has been key to successful planning and implementation. While technology plays an important role, lessons learned on the land are critical and will inform efforts to include language and ceremony in future programming. Dietitians are encouraged to support Indigenous-led land-based learning in support of the profession's commitment to reconciliation.

Developing a long-term follow up service for bariatric surgical patients in the community: Patient and professional perspectives.

Background: In the UK, bariatric surgical patients are followed up for 2 years post-operatively in hospital settings, before being discharged into General Practice for long-term follow-up. Presently, there is ambiguous guidance as to what should be included in a community-based bariatric surgical follow-up service. The aim of the study was to understand, from both patient and professional perspectives, what is needed to support the long-term management of bariatric surgical patients in community-based settings. Methods: Post-surgical bariatric patients and General Practice staff were recruited from an area in the UK which has an National Health Service (NHS) hospital providing a high-volume and established bariatric surgical service. Data was collected through semi-structured interviews. A thematic analytic framework was used to construct eight themes which illuminated the participants' experiences. The study took place between March and December 2021. Findings: Thirty participants (14 patients and 16 healthcare professionals) were recruited to the study. The study revealed the lack of a framework for delivery of a long-term follow up service was frustrating to both patients and professionals. Patient participants reported needing more support, especially dietetic and psychological input, and professionals stated they had little knowledge about bariatric surgical care, and what was needed to provide optimal care, but wanted to provide quality patient care. Conclusion: Long-term follow up of bariatric surgical patients is an important issue which needs addressing. This study illuminates both the patient and professional perspectives on developing a pragmatic, community-based service which meets the needs of patients and considers the need to incorporate such a service into existing infrastructures without adding additional demands on General Practice.

Pressure ulcer prevention in practice.

Pressure ulcer avoidance in the context of care has the potential to improve the quality and longevity of lives for those living in residential and non-residential care home settings. This paper reports on an educational intervention in the North East of England, which focused on the initial benchmarking of self-reported knowledge levels of healthcare workers, who regularly work with people living within this context. Using a longitudinal study design, a series of three questionnaires were used to collate data from research participants. The study revealed a disparity between what healthcare workers perceived their knowledge to be versus what it was, in terms of application to practice at the front line of patient care. The study reveals that confidence levels in dealing with pressure ulceration had been significantly altered by the training session that was being implemented. It also raised concerns on the methodological approaches being used in the education and training of care staff, which should ideally lead them to be proactive with patients in their care. The study provides an insight into the need for a strategic and targeted approach to pressure ulceration avoidance education, which is tailored to individual learning needs through supervision and mentorship as part of clinical education.

A systematic review of obesity as a barrier to accessing cancer screening services.

Introduction: Obesity is a known risk factor for the development of cancers, and a significant proportion of the population may be at risk of developing cancer owing to their weight status. There is acknowledged societal stigma towards people living with obesity, which can influence health behaviors and deter help seeking, such as cancer screening. Healthcare professionals' attitudes and views toward people living with obesity may adversely affect the patient-professional interface and treatment. Methods: A systematic review was carried out which aimed to explore the impact of living with obesity on the uptake of three main cancer-screening services: breast, cervical, and colorectal. Results: Ten studies were included in the review. Three main areas were identified from both a patient and healthcare professional perspective: barriers and challenges to screening, gender issues, and disparities in the population living with obesity. Conclusion: Further research is needed to improve uptake of cancer screening services, and for education on weight bias, which is often unconscious, to be considered for healthcare professionals working in cancer screening services. This may help to increase the incidence of early differential diagnosis of potential cancers and improve health outcomes for people living with obesity.

A randomized controlled trial to evaluate the effectiveness of a novel mouth rinse in patients with gingivitis.

BACKGROUND: This single-center, randomized controlled trial aimed to determine the effectiveness of a novel, biofilm-disrupting, mouth rinse that combines Cetylpyridinium chloride (CPC) and essential oils in preventing re-accumulation of supragingival plaque and supragingival microbiome in patients with gingivitis after dental prophylaxis. METHODS: One hundred eighteen participants were randomly assigned in a 1:1 ratio to receive twice-daily test mouth rinse (59) or carrier rinse control (59) for 12 weeks after dental prophylaxis. RESULTS: In a per-protocol analysis that included patients who completed the intervention, the treatment group (39) had significantly lower supragingival plaque scores at 6 and 12 weeks compared to the control group (41; p = 0.022). Both groups showed similar improvement in gingivitis score, but neither group had improvement in bleeding score or probing depth. Thirty-eight (29%) patients did not complete the study due to loss of follow-up (17) or early discontinuation of the assigned intervention (21). Microbiome sequencing showed that the treatment rinse significantly depleted abundant and prevalent members of the supragingival plaque microbiome consortium. CONCLUSIONS: Among patients with gingivitis, the novel mouth rinse significantly reduced re-accumulation of supragingival plaque following dental prophylaxis by depleting supragingival plaque microbiome. However, long-term adherence to the rinse may be limited by adverse effects ( ClinicalTrials.gov number, NCT03154021).

Fusobacterium is enriched in oral cancer and promotes induction of programmed death-ligand 1 (PD-L1).

Recently, increased number of studies have demonstrated a relationship between the oral microbiome and development of head and neck cancer, however, there are few studies to investigate the role of oral bacteria in the context of the tumor microenvironment in a single head and neck subsite. Here, paired tumor and adjacent normal tissues from thirty-seven oral tongue squamous cell carcinoma (SCC) patients were subjected to 16S rRNA gene sequencing and whole exome sequencing (WES), in addition to RNA sequencing for tumor samples. We observed that Fusobacterium was significantly enriched in oral tongue cancer and that Rothia and Streptococcus were enriched in adjacent normal tissues. A decrease in alpha diversity was found in tumor when compared to adjacent normal tissues. While increased Fusobacterium in tumor samples was not associated with changes in immune cell infiltration, it was associated with increased PD-L1 mRNA expression. Therefore, we examined the effects of Fusobacterium on PD-L1 expression in head and neck SCC cell lines. We demonstrated that infection with Fusobacterium species can increase both PD-L1 mRNA and surface PD-L1 protein expression on head and neck cancer cell lines. The correlation between Fusobacterium and PD-L1 expression in oral tongue SCC, in conjunction with the ability of the bacterium to induce PD-L1 expression in vitro suggests a potential role for Fusobacterium on modulation of the tumor immune microenvironment in head and neck cancer.

Novel pfk13 polymorphisms in Plasmodium falciparum population in Ghana.

The molecular determinants of Plasmodium falciparum artemisinin resistance are the single nucleotide polymorphisms in the parasite's kelch propeller domain, pfk13. Validated and candidate markers are under surveillance in malaria endemic countries using artemisinin-based combination therapy. However, pfk13 mutations which may confer parasite artemisinin resistance in Africa remains elusive. It has therefore become imperative to report all observed pfk13 gene polymorphisms in malaria therapeutic efficacy studies for functional characterization. We herein report all novel pfk13 mutations observed only in the Ghanaian parasite population. In all, 977 archived samples from children aged 12 years and below with uncomplicated malaria from 2007 to 2017 were used. PCR/Sanger sequencing analysis revealed 78% (763/977) of the samples analyzed were wild type (WT) for pfk13 gene. Of the 214 (22%) mutants, 78 were novel mutations observed only in Ghana. The novel SNPs include R404G, P413H, N458D/H/I, C473W/S, R529I, M579T/Y, C580R/V, D584L, N585H/I, Q661G/L. Some of the mutations were sites and ecological zones specific. There was low nucleotide diversity and purifying selection at the pfk13 locus in Ghanaian parasite population. With increasing drug pressure and its consequent parasite resistance, documenting these mutations as baseline data is crucial for future molecular surveillance of P. falciparum resistance to artemisinin in Ghana.

School Bag-Related Factors and Their Implications for Walking and Cycling to School among New Zealand Adolescents.

Excessive school bag weight may be a modifiable barrier to active transport to school. This study examined correlates of school bag weight and adolescents' perceptions of excessive school bag weight for walking and cycling to school among New Zealand adolescents living in diverse settlement types. Adolescents (n = 1512; 15.0 ± 1.3 years) completed a questionnaire and had their bag weight (n = 1190) and body weight (n = 1038) measured. Adolescents using active transport and rural adolescents had lighter school bags compared to their counterparts. One-third of adolescents reported excessive school bag weight for walking (31.2%) and cycling (37.2%) to school. Positive correlates of relative school bag weight were female gender (regression coefficient (95% CI): 0.53 (0.13, 0.93)), and underweight (2.21 (1.39, 3.02)), whereas negative correlates were Maori ethnicity (-0.87 (-1.41, -0.32)), overweight (-1.84 (-2.35, -1.34)) and obesity (-3.57 (-4.26, -2.87)), and school location in small urban areas (-2.10 (-4.19, -0.01)), and rural settlements (-3.58 (-5.66, -1.49)). Older adolescents, females, those with greater relative school bag weight, and those experiencing school bag-related pain symptoms and/or fatigue were more likely to report excessive school bag weight for both walking and cycling to school. Future initiatives should target reducing excessive school bag weight, particularly in female and urban adolescents.

Defining Clinical Public Health.

PURPOSE: To solve complex health issues, an innovative and multidisciplinary framework is necessary. The Clinical Public Health (CPH) Division was established at the University of Toronto (UofT), Canada to foster inte-gration of primary care, preventive medicine and public health in education, practice and research. To better understand how the construct of CPH might be applied, we surveyed clinicians, researchers and public health professionals affiliated with the CPH Division to assess their understanding of the CPH concept and its utility in fostering broad collaboration. METHODS: A two-wave anonymous survey of the active faculty of the CPH Division, UofT was conducted across Canada. Wave 1 participants (n = 187; 2016) were asked to define CPH, while Wave 2 participants (n = 192; 2017) were provided a synthesis of Wave 1 results and asked to rank each definition. Both waves were asked about the need for a common definition, and to comment on CPH. RESULTS: Response rates for the first and second waves were 25% and 22%, respectively. Of the six definitions of CPH from Wave 1, "the intersection of clinical practice and public health," was most highly ranked by Wave 2 participants. Positive perceptions of CPH included multidisciplinary collaboration, new fields and insights, forward thinking and innovation. Negative perceptions included CPH being a confusing term, too narrow in scope or too clinical. CONCLUSION: The concept of Clinical Public Health can foster multidisciplinary collaboration to address com-plex health issues because it provides a useful framework for bringing together key disciplines and diverse professional specialties.

Subgingival microbiome of deep and shallow periodontal sites in patients with rheumatoid arthritis: a pilot study.

BACKGROUND: Subgingival microbiome in disease-associated subgingival sites is known to be dysbiotic and significantly altered. In patients with rheumatoid arthritis (RA), the extent of dysbiosis in disease- and health-associated subgingival sites is not clear. METHODS: 8 RA and 10 non-RA subjects were recruited for this pilot study. All subjects received full oral examination and underwent collection of subgingival plaque samples from both shallow (periodontal health-associated, probing depth ≤ 3mm) and deep subgingival sites (periodontal disease-associated, probing depth ≥ 4 mm). RA subjects also had rheumatological evaluation. Plaque community profiles were analyzed using 16 S rRNA sequencing. RESULTS: The phylogenetic diversity of microbial communities in both RA and non-RA controls was significantly higher in deep subgingival sites compared to shallow sites (p = 0.022), and the overall subgingival microbiome clustered primarily according to probing depth (i.e. shallow versus deep sites), and not separated by RA status. While a large number of differentially abundant taxa and gene functions was observed between deep and shallow sites as expected in non-RA controls, we found very few differentially abundant taxa and gene functions between deep and shallow sites in RA subjects. In addition, compared to non-RA controls, the UniFrac distances between deep and shallow sites in RA subjects were smaller, suggesting increased similarity between deep and shallow subgingival microbiome in RA. Streptococcus parasanguinis and Actinomyces meyeri were overabundant in RA subjects, while Gemella morbillorum, Kingella denitrificans, Prevotella melaninogenica and Leptotrichia spp. were more abundant in non-RA subjects. CONCLUSIONS: The aggregate subgingival microbiome was not significantly different between individuals with and without rheumatoid arthritis. Although the differences in the overall subgingival microbiome was driven primarily by probing depth, in contrast to the substantial microbiome differences typically seen between deep and shallow sites in non-RA patients, the microbiome of deep and shallow sites in RA patients were more similar to each other. These results suggest that factors associated with RA may modulate the ecology of subgingival microbiome and its relationship to periodontal disease, the basis of which remains unknown but warrants further investigation.

A Novel Regulation of K-antigen Capsule Synthesis in Porphyromonas gingivalis Is Driven by the Response Regulator PG0720-Directed Antisense RNA.

The periodontal pathogen Porphyromonas gingivalis strain W83 displays at least three different surface glycans, specifically two types of lipopolysaccharides (O-LPS and A-LPS) and K-antigen capsule. Despite the importance of K-antigen capsule to the virulence of P. gingivalis, little is known as to how expression of genes involved in the synthesis of this surface glycan is regulated. The genes required for K-antigen capsule synthesis are located in a locus that encodes a number of transcripts, including an operon (PG0104 to PG0121, generating ~19.4-kb transcript) which contains a non-coding 77-bp inverted repeat (77 bpIR) region near the 5'-end. Previously, we identified a 550-nucleotide antisense RNA molecule (designated asSuGR for antisense Surface Glycan Regulator) encoded within the 77-bpIR element that influences the synthesis of surface glycans. In this study, we demonstrate that the DNA-binding response regulator PG0720 can bind the promoter region of asSuGR and activate expression of asSuGR, indicating that PG0720 may indirectly influence transcript levels of the K-antigen capsule operon expressed from the sense strand. The data show that deletion of the PG0720 gene confers a defect in the presentation of surface polysaccharides compared with the parent strain and quantitative RT-PCR (qPCR) analysis determined that the overall expression of genes involved in K-antigen capsule synthesis were down-regulated in the PG0720 mutant. Furthermore, the defects of the PG0720 deletion mutant were restored by complementation. Importantly, the PG0720 deletion mutant showed reduced virulence. Altogether, our data show that the response regulator PG0720 regulates expression of asSuGR, a trans-acting antisense RNA molecule involved in modulating the production of surface polysaccharides in P. gingivalis strain W83. The data provide further evidence that surface glycans are key virulence determinants and significantly advances our understanding of the molecular mechanisms controlling the synthesis of P. gingivalis K-antigen capsule, a key virulence determinant.

Evaluating a potential role for community pharmacists in post-bariatric patient nutritional support.

Physiological changes to the body from bariatric surgery necessitate lifelong vitamin and mineral supplementation to prevent potential nutritional deficiencies. Presently, there is no consensus on appropriate long-term follow-up in community settings for people who have undergone bariatric surgery. Current UK guidelines recommend annual monitoring of nutritional status, but little else. Semi-structured interviews were carried out with members of a high volume bariatric surgical unit and community pharmacists working in a variety of settings and locations. Data were collected between June and August 2018 and analysed using a thematic analytic framework. Twenty-five participants were recruited. Bariatric staff (n = 9) reported negligible interaction with community pharmacists but felt establishing communication and developing a potential pathway to collaborate, would provide additional support and potentially improved levels of patient compliance. Community pharmacists (n = 16) reported poor knowledge of bariatric surgery, indicating they were unable to routinely identify people who had bariatric surgery, but understood issues with absorption of vitamins. There is evident potential to involve community pharmacists in post-bariatric patient care pathways. Pharmacists possess knowledge of absorption and metabolism of supplements which could be used to actively support people who have had bariatric surgery in their changed physiological status. Education ought to focus on the functional impact of bariatric surgical procedures and interventions and the consequent nutritional recommendations required. Communication between bariatric units and community pharmacies is needed to construct a clear and formalized infrastructure of support, with remuneration for pharmacy specialist expertise agreed to ensure both financial viability and sustainability.

A Uniquely Altered Oral Microbiome Composition Was Observed in Pregnant Rats With Porphyromonas gingivalis Induced Periodontal Disease.

Porphyromonas gingivalis is an anaerobic bacterium commonly found in the oral cavity and associated with the development of periodontal disease. P. gingivalis has also been linked to several systemic vascular and inflammatory diseases including poor pregnancy outcomes. Little is known about the changes in the oral flora during pregnancy in connection to P. gingivalis infection. This pilot study aims to explore changes in the oral microbiome due to P. gingivalis inoculation and pregnancy in an in vivo rat model of periodontal disease. A metagenomic sequencing analysis targeting seven of the 16S rRNA gene variable regions was performed for oral samples collected at the following time points: baseline control (week 0), P. gingivalis inoculated (week 11), P. gingivalis inoculated and pregnant rat at necropsy (week 16). A second set of animals were also sampled to generate a sham-inoculated (week 11) control group. We found that the rat oral microbiome profiles were more similar to that of the human oral cavity compared to previous reports targeting one or two 16S variable regions. Overall, there appears to be a relatively stable core microbiome in the oral cavity. As expected, P. gingivalis induced periodontal disease resulted in oral microbiome dysbiosis. During pregnancy, some aspects of the oral microbiome shifted toward a more baseline-like profile. However, population analyses in terms of dissimilarity measures and especially metagenomic based predictions of select characteristics such as cell morphology, oxygen requirement, and major metabolite synthesis showed that pregnancy did not restore the composition of the oral microbiome. Rather, a uniquely altered oral microbiome composition was observed in pregnant rats with pre-established periodontal disease.

Fusobacteria modulate oral carcinogenesis and promote cancer progression.

Background: Evidence suggest periodontal bacterial infection can contribute to oral cancer initiation and progression. Aim: To investigate the effects of periodontal bacteria on oral cancer cell behavior using a cell-based system and a mouse carcinogenesis model. Methods: Oral cancer cell lines were polyinfected with four periodontal bacteria. Cytokine levels and relative changes in oncogene mRNA expression were determined post-infection. Oral tumours in mice induced by 4-nitroquinoline-1-oxide (4NQO) were compared with and without administrating periodontal bacteria. Results: Polyinfected oral cancer cells had upregulated MMP1, MMP9, and IL-8. The expression of cell survival markers MYC, JAK1, and STAT3 and epithelial-mesenchymal transition markers ZEB1 and TGF-ß were also significantly elevated. Monoinfections showed F. nucleatum alone had comparable or greater effects than the four bacteria together. Fusobacterial culture supernatant, primarily LPS, was sufficient to induce IL-8 secretion, demonstrating that direct contact of live Fusobacteria with cancer cells might not be required to exert changes in cancer cell behaviour. In the 4NQO-induced oral tumour model, mice infected with bacteria developed significantly larger and more numerous lesions compared to those not infected. Conclusion: This study demonstrated that Fusobacteria could potentially enhance cancer cell invasiveness, survival, and EMT when presented in the oral tumour microenvironment. Abbreviations: 4NQO, 4-nitroquinoline-1-oxide; ELISA, enzyme-linked immunosorbent assay; EMT, epithelial-mesenchymal transition; IL-8, interleukin-8; JAK1, Janus kinase 1; LPS, lipopolysaccharide; MMP, matrix metalloproteinase; OSCCs, oral squamous cell carcinomas; PK, proteinase K; PMB, Polymyxin B; qRT-PCR, quantitative real-time polymerase chain reaction; STAT3, signal transducer and activator of transcription 3; TGF-ß, transforming growth factor beta; ZEB1, zinc finger E-Box binding homeobox 1.

The Importance of Being an Antagonist as Well as Persistent.

The current work by Jain et al. (S. Jain, A. M. Chang, M. Singh, J. S. McLean, et al., J Bacteriol 201:e00683-18, 2019, https://doi.org/10.1128/JB.00683-18) reports the cloning of the lipid A deacylase gene of Porphyromonas gingivalis and the phenotypic characterization of the enzyme. Attempts to clone the gene and thus provide proof of the existence of this enzyme had gone on for 2 decades. The enzyme is central to the bacterium's ability to modify and tailor the structure of its lipid A, changing a lipid A that is a moderate Toll-like receptor 4 (TLR4) agonist to an antagonist or silencer and thereby potentially changing the course of infection.

Exploring Food Guidance Approaches for Seniors in Antigonish, NS: Is There Still Gold at the End of the Rainbow?

Purpose: As Canada rethinks approaches to food guidance, insights into the needs of seniors in rural communities are important to ensure their nutrition issues are addressed. This study aimed to explore the food guidance needs and wants of a group of seniors living in Antigonish, Nova Scotia. Methods: Three focus groups were held with a total of 12 participants over the age of 65 years, living independently in the community. Seniors were asked about their views on Canada's Food Guide (CFG) and the Brazilian Dietary Guidelines (BDG). Results: Participants identified CFG as a trusted source of information and related well to the food groups and directive statements. Portion sizes were confusing and advice on food choices was not seen as being realistic in terms of cost and availability. The holistic nature of the BDG was appealing but guidance on processed food and social eating was not seen as relevant. Neither guidance tool addressed concerns about sustainability and environmental issues. Point of purchase nutrition information was preferable to receiving it from health professionals. Conclusion: CFG was seen as a trusted source of advice; however, locally accessible guidance on affordability and environmental issues related to food choice is needed for this group.

Dataset on the chemokine and cytokine responses of multi-cell cultures treated with Porphyromonas gingivalis hemagglutinin B.

Chemokines and cytokines produced in gingival tissues exposed to microorganisms and microbial products in dental plaque lead to local inflammation and tissue damage seen in periodontal disease. Bates et al. 2018 [1] reported that Porphyromonas gingivalis hemagglutinin B (HagB)-induced matrix metalloproteinase (MMP) responses of single cell cultures containing dendritic cells, gingival epithelial (GE) keratinocytes, or T cells were significantly different from the MMP responses of these same cells grown in multi-cell cultures. Here we report the concentrations (pg/ml) of HagB-induced IL1α, IL6, IL8, IL12(p40), GM-CSF, MIP1α, MIP1ß, RANTES, TNFα, and VEGF produced by dendritic cells, GE keratinocytes, or T cells in single cell cultures, two-cell cultures, or three-cell cultures.

Matrix Metalloproteinase Response of Dendritic Cell, Gingival Epithelial Keratinocyte, and T-Cell Transwell Co-Cultures Treated with Porphyromonas gingivalis Hemagglutinin-B.

Matrix metalloproteinases (MMPs) are enzymes involved in periodontal tissue destruction. Hemagglutinin B (HagB) from the periodontal pathogen Porphyromonas gingivalis induces an elevated MMP response in dendritic cells, but responses from cultures of single-cell types do not reflect the local tissue environment. The objective of this study was to measure HagB-induced MMP responses in a transwell co-culture system containing dendritic cells, gingival epithelial (GE) keratinocytes, and CD4+ T-cells. Transwell co-cultures were assembled and treated with or without HagB. Immunoassays were used to determine production of MMP1, MMP7, MMP9, and MMP12 in response to HagB up to 64 h. Control responses were subtracted from HagB-induced responses. A two-way fixed effect ANOVA was fit to log-transformed concentrations and pairwise group comparisons were conducted (p < 0.05). At 64 h, dendritic cells produced elevated MMP1 and MMP9 responses, which were attenuated in the 3-cell co-culture (p < 0.05). There were also significant differences in MMP7 and MMP12 production between single-cell cultures and co-cultures. These results support the need to use multiple cell types in culture models to evaluate a more representative response to proinflammatory agonists. This three-cell transwell co-culture model may help us better understand the inflammatory process in periodontal disease and test novel therapeutic approaches.

Deletion of a conserved transcript PG_RS02100 expressed during logarithmic growth in Porphyromonas gingivalis results in hyperpigmentation and increased tolerance to oxidative stress.

The oral obligate anaerobe Porphyromonas gingivalis possesses a small conserved transcript PG_RS02100 of unknown function we previously identified using small RNA-seq analysis as expressed during logarithmic growth. In this study, we sought to determine if PG_RS02100 plays a role in P. gingivalis growth or stress response. We show that a PG_RS02100 deletion mutant's (W83Δ514) ability to grow under anaerobic conditions was no different than wildtype (W83), but it was better able to survive hydrogen peroxide exposure when cultured under heme limiting growth conditions, and was more aerotolerant when plated on enriched whole blood agar and exposed to atmospheric oxygen. Together, these results indicate that PG_RS02100 plays a role in surviving oxidative stress in actively growing P. gingivalis and that P. gingivalis' response to exogenous hydrogen peroxide stress is linked to heme availability. Relative qRT-PCR expression analysis of oxyR, trx-1, tpx, sodB, ahpC, dinF, cydB, and frd, in W83Δ514 and W83 in response to 1 h exogenous dioxygen or hydrogen peroxide exposure, when cultured with varying heme availability, support our phenotypic evidence that W83Δ514 has a more highly primed defense system against exogenous peroxide, dioxygen, and heme generated ROS. Interestingly, W83Δ514 turned black faster than W83 when cultured on whole blood agar, suggesting it was able to accumulate heme more rapidly. The mechanism of increased heme acquisition observed in W83Δ514 is not yet known. However, it is clear that PG_RS02100 is involved in modulating the P. gingivalis cell surface in a manner related to survival, particularly against oxidative stress.