Exploring Salivary Epithelial Dysfunction in Sjögren's Disease.

Sjögren's Disease (SjD) is an autoimmune disease of the exocrine tissues. Etiological events result in the loss of epithelial homeostasis alongside extracellular matrix (ECM) destruction within the salivary and lacrimal glands, followed by immune cell infiltration. In this review, we have assessed the current understanding of epithelial-mesenchymal transition (EMT)-associated changes within the salivary epithelium potentially involved in salivary dysfunction and SjD pathogenesis. We performed a PubMed literature review pertaining to the determination of pathogenic events that lead to EMT-related epithelial dysfunction and signaling in SjD. Molecular patterns of epithelial dysfunction in SjD salivary glands share commonalities with EMT mediating wound healing. Pathological changes altering salivary gland integrity and function may precede direct immune involvement while perpetuating MMP9-mediated ECM destruction, inflammatory mediator expression, and eventual immune cell infiltration. Dysregulation of EMT-associated factors is present in the salivary epithelium of SjD and may be significant in initiating and perpetuating the disease. In this review, we further highlight the gap regarding mechanisms that drive epithelial dysfunction in salivary glands in the early or subclinical pre-lymphocytic infiltration stages of SjD.

Identification of single nucleotide polymorphisms (SNPs) associated with chronic graft-versus-host disease in patients undergoing allogeneic hematopoietic cell transplantation.

INTRODUCTION: Chronic graft-versus-host disease (cGVHD) is a debilitating side effect of allogeneic hematopoietic cell transplantation (HCT), affecting the quality of life of patients. We used whole exome sequencing to identify candidate SNPs and complete a multi-marker gene-level analysis using a cohort of cGVHD( +) (N = 16) and cGVHD( -) (N = 66) HCT patients. METHODS: Saliva samples were collected from HCT patients (N = 82) pre-conditioning in a multi-center study from March 2011 to May 2018. Exome sequencing was performed and FASTQ files were processed for sequence alignments. Significant SNPs were identified by logistic regression using PLINK2v3.7 and Fisher's exact test. One cGVHD( -) patient sample was excluded from further analysis since no SNP was present in at least 10% of the sample population. The FUMA platform's SNP2GENE was utilized to annotate SNPs and generate a MAGMA output. Chromatin state visualization of lead SNPs was completed using Epilogos tool. FUMA's GENE2FUNC was used to obtain gene function and tissue expression from lead genomic loci. RESULTS: Logistic regression classified 986 SNPs associated with cGVHD( +). SNP2GENE returned three genomic risk loci, four lead SNPs, 48 candidate SNPs, seven candidate GWAS tagged SNPs, and four mapped genes. Fisher's exact test identified significant homozygous genotypes of four lead SNPs (p < 0.05). GENE2FUNC analysis of multi-marker SNP sets identified one positional gene set including lead SNPs for KANK1 and KDM4C and two curated gene sets including lead SNPs for PTPRD, KDM4C, and/or KANK1. CONCLUSIONS: Our data suggest that SNPs in three genes located on chromosome 9 confer genetic susceptibility to cGVHD in HCT patients. These genes modulate STAT3 expression and phosphorylation in cancer pathogenesis. The findings may have implications in the modulation of pathways currently targeted by JAK inhibitors in cGVHD clinical trials.

Telomere erosion in Sjögren's syndrome: A multi-tissue comparative analysis.

BACKGROUND: Acinar progenitor cells within salivary glands have decreased regenerative capacity and exhibit shorter telomeres in primary Sjögren's syndrome (pSS) patients. We investigated whether DNA of saliva, PBMCs, and labial salivary gland (LSG) biopsy tissue have shorter telomeres in pSS compared to controls. mRNA expression of genes associated with pSS pathogenesis (ETS1, LEF1, and MMP9), telomere DNA damage response (ATM), senescence (CDKN2A), telomerase inhibition (IFN-y, TGFß1), and the shelterin complex (TPP1, POT1) were assessed in LSG tissue by qRT-PCR to examine potential defects in telomere maintenance. METHODS: Relative telomere length in DNA of saliva, PBMCs, and LSGs from non-pSS sicca and pSS patients was measured using qPCR. Saliva DNA telomere length was further compared to healthy controls. Expression of genes affecting telomere maintenance was analyzed in LSGs using qRT-PCR. RESULTS: Primary Sjögren's syndrome patients have shorter telomeres in saliva DNA (n = 21) than healthy controls (n = 27) (P = .0035). ATM mRNA expression was higher in pSS LSG tissue (n = 16) vs non-pSS sicca patients (n = 13) (P = .0283) and strongly correlated with LEF1, TPP1, and POT1 (P < .01, r > 0.6). CONCLUSIONS: Patients with pSS exhibited significant telomere erosion in saliva DNA. Overexpression of ATM in LSGs could represent a compensatory response to telomere shortening. The role of LEF1 in telomere erosion remains to be elucidated.

Comparison of culture and molecular techniques for microbial community characterization in infected necrotizing pancreatitis.

BACKGROUND: Infected necrotizing pancreatitis is associated with significant morbidity and mortality. Peripancreatic fluid cultures may fail to identify all the infecting organisms. The aim of this study was to compare the bacterial biome of peripancreatic fluid from infected necrotizing pancreatitis patients using 16S ribosomal RNA (rRNA) DNA deep sequencing and quantitative polymerase chain reaction (qPCR) targeting the 16S rRNA gene versus standard laboratory culture. MATERIALS AND METHODS: Peripancreatic fluid was collected during operative or radiologic intervention and samples sent for culture. In parallel, microbial DNA was extracted, qPCR targeting the 16S rRNA gene and 16S rRNA PCR amplification followed by Illumina deep sequencing were performed. RESULTS: Using culture techniques, the bacterial strains most frequently identified were gram-negative rods (Escherichia coli, Klebsiella pneumoniae) and Enterococcus. Samples in which culture results were negative had copy numbers of the 16S rRNA gene close to background in qPCR analysis. For samples with high bacterial load, sequencing results were in some cases in good agreement with culture data, whereas in others there were disagreements, likely due to differences in taxonomic classification, cultivability, and differing susceptibility to background contamination. Sequencing results appeared generally unreliable in cases of negative culture where little microbial DNA was input into qPCR sequencing reactions. CONCLUSIONS: Both sequencing and culture data display their own sources of bias and potential error. Consideration of data from multiple techniques will yield a more accurate view of bacterial infections than can be achieved by any single technique.

Oral microbiomes of patients with infective endocarditis (IE): a comparative pilot study of IE patients, patients at risk for IE and healthy controls.

Background: Infective endocarditis (IE) is an uncommon disease with high morbidity and mortality rates, which often develops from oral bacterial species entering circulation. Objective: We compared oral microbiome profiles of three groups: IE patients (N  9 patients; n = 27 samples), disease controls at risk for IE (N = 28; n = 84), and healthy controls (N = 37; n = 111). Bacterial species in IE patients' blood cultures were identified for comparison with matched oral samples. Design: Oral microbiome profiles were obtained from buccal mucosa, saliva, and tongue samples for all three groups and from sub- and supra-gingival plaque samples of the IE group (N = 9; n = 16) and disease controls (N = 28; n = 54). Alpha- and beta-diversities were determined based on relative abundance data. Discriminative species were identified by LEfSe, post hoc Mann-Whitney, and ROC analyses. Identity of the bacterial species in IE patients' blood cultures was confirmed by 16S-rRNA gene Sanger sequencing. Results: Alpha- and beta-diversities differed between groups. Discriminative IE-associated species were identified, e.g. Haemophilus parainfluenzae and Streptococcus sanguinis. Two blood isolates were Staphylococcus aureus, also identified in one matched saliva sample. Streptococcus mutans was present in one patient's plaque samples and blood culture. Conclusions: Oral microbiomes of IE, non-IE disease controls, and healthy controls differed significantly. A better understanding of IE-related bacterial-host interactions is warranted.

Human oral mucosa and oral microbiome interactions following supragingival plaque reconstitution in healthy volunteers: a diet-controlled balanced design proof-of-concept model to investigate oral pathologies.

Changes in the oral microbiome may contribute to oral pathologies, especially in patients undergoing cancer therapy. Interactions between oral microbiome and oral mucosa may exacerbate inflammation. We determined whether probiotic-controlled plaque formation could impact proximal oral mucosa gene expression profiles in healthy volunteers. A 3-weeks balanced sample collection design from healthy volunteers (HVs) was implemented. At Week-1 plaques samples and labial mucosa brush biopsies were obtained from HVs in the morning (N = 4) and/or in the afternoon (N = 4), and groups were flipped at Week-3. A fruit yogurt and tea diet were given 2-4hrs before sample collection. mRNA gene expression analysis was completed using RNA-Seq and DESeq2. Bacterial taxa relative abundance was determined by 16S HOMINGS. Bacterial diversity changes and metabolic pathway enrichment were determined using PRIMERv7 and LEfSe programs. Alpha- and beta-diversities did not differ morning (AM) vs. afternoon (PM). The most affected KEGG pathway was Toll-like receptor signaling in oral mucosa. Eighteen human genes and nine bacterial genes were differentially expressed in plaque samples. Increased activity for 'caries-free' health-associated calcifying Corynebacterium matruchotii and reduced activity for Aggregatibacter aphrophilus, an opportunistic pathogen, were observed. Microbial diversity was not altered after 8 hours plaque formation in healthy individuals as opposed to gene expression.

Cutaneous Microbiome Profiles Following Chlorhexidine Treatment in a 72-Hour Daily Follow-Up Paired Design: a Pilot Study.

Venous catheter-related bloodstream infections represent a significant problem in the United States. Our objective was to determine daily changes in skin microbiome profiles up to 72h postchlorhexidine treatment. Left and right forearm skin swab samples were obtained from 10 healthy volunteers over 72h at 24h intervals. Dorsal surface of left arm was treated with chlorohexidine gluconate (CHG) at initial time point (T = 0), while the right arm remained untreated (control). Swab samples were obtained shortly before (T = 0) and after CHG treatment (T = 24-48-72h). Bacterial DNA extraction, 16S rRNA gene V1-V3 sequencing and taxonomic annotation were performed using ZymoBIOMICS pipeline. PERMANOVA, linear discriminant and bacterial interaction network analyses were performed. A total of 13 total phyla, 273 genera, and 950 total species were detected across all time points, CHG-treated or CHG-untreated. Most abundant species included Cutibacterium acnes, Staphylococcus epidermidis, and Rothia Mucilaginosa. Low biomass-related inconsistent taxa detection was observed. PERMANOVA suggested a marginal difference between CHG-treated and CHG-untreated microbiome profiles (Genera: P(perm) = 0.0531; Species: P(perm) = 0.0450). Bacterial interaction network guided PERMANOVA analyses detected a microbiome change over time, suggesting a consistent CHG treatment-specific change. LEfSe identified Finegoldia magna, Bacillus pumilus, Bacillus thermoamylovorans as the only distinctive species. These species were more abundant and/or present post-CHG treatment in the CHG-treated group. These findings suggest that the skin microbiome was not significantly different 24, 48, or 72h after CHG treatment. Previous culture-based studies have found similar results after 24h. Future studies will be needed to determine the mechanisms of bacterial regrowth after CHG treatment. IMPORTANCE Annually, over 80,000 central line infections occur in the United States. Understanding the pathogenesis of these infections is crucial. Chlorhexidine is the most commonly used skin preparation before line placement. We hypothesized that the use of chlorhexidine and dressings will alter the normal arm skin microbiome over a period of 72h. We used 16S-rRNA gene next generation sequencing (NGS) to determine the forearm skin microbiome of volunteers. The left arm was swabbed with chlorhexidine and the right arm served as control. The skin microbiome returned to normal after 24h. Our NGS results confirm findings of two previous culture-based studies. Relative abundance of Bacillus spp. in the chlorhexidine-treated samples was increased, consistent with one previous study. Based on the results of this pilot study, we will need to measure viable bacteria during a 24h time course following chlorhexidine treatment to understand the source of skin microbiome replenishment.

Haemophilus pittmaniae and Leptotrichia spp. Constitute a Multi-Marker Signature in a Cohort of Human Papillomavirus-Positive Head and Neck Cancer Patients.

OBJECTIVES: Human papillomavirus (HPV) is a known etiological factor of oropharyngeal head and neck cancer (HNC). HPV positivity and periodontal disease have been associated with higher HNC risk, suggesting a role for oral bacterial species. Our objective was to determine oral microbiome profiles in HNC patients (HPV-positive and HPV-negative) and in healthy controls (HC). METHODS: Saliva samples and swabs of buccal mucosa, supragingival plaque, and tongue were collected from HNC patients (N = 23 patients, n = 92 samples) before cancer therapy. Next-generation sequencing (16S-rRNA gene V3-V4 region) was used to determine bacterial taxa relative abundance (RA). ß-Diversities of HNC HPV+ (N = 16 patients, n = 64 samples) and HNC HPV- (N = 7 patients, n = 28 samples) groups were compared using PERMANOVA (pMonte Carlo < 0.05). LEfSe discriminant analysis was performed to identify differentiating taxa (Log LDA > 2.0). RA differences were analyzed by Mann-Whitney U-test (α = 0.05). CombiROC program was used to determine multi-marker bacterial signatures. The Microbial Interaction Network Database (MIND) and LitSuggest online tools were used for complementary analyses. RESULTS: HNC vs. HC and HNC HPV+ vs. HNC HPV- ß-diversities differed significantly (pMonte Carlo < 0.05). Streptococcus was the most abundant genus for HNC and HC groups, while Rothia mucilaginosa and Haemophilus parainfluenzae were the most abundant species in HNC and HC patients, respectively, regardless of antibiotics treatment. LEfSe analysis identified 43 and 44 distinctive species for HNC HPV+ and HNC HPV- groups, respectively. In HNC HPV+ group, 26 periodontal disease-associated species identified by LefSe had a higher average RA compared to HNC HPV- group. The significant species included Alloprevotella tannerae, Fusobacterium periodonticum, Haemophilus pittmaniae, Lachnoanaerobaulum orale, and Leptotrichia spp. (Mann-Whitney U-test, p < 0.05). Of 43 LEfSe-identified species in HPV+ group, 31 had a higher RA compared to HPV- group (Mann-Whitney U-test, p < 0.05). MIND analysis confirmed interactions between Haemophilus and Leptotrichia spp., representing a multi-marker signature per CombiROC analysis [area under the curve (AUC) > 0.9]. LitSuggest correctly classified 15 articles relevant to oral microbiome and HPV status. CONCLUSION: Oral microbiome profiles of HNC HPV+ and HNC HPV- patients differed significantly regarding periodontal-associated species. Our results suggest that oral bacterial species (e.g., Leptotrichia spp.), possessing unique niches and invasive properties, coexist with HPV within HPV-induced oral lesions in HNC patients. Further investigation into host-microbe interactions in HPV-positive HNC patients may shed light into cancer development.

Oral Microbiome Signatures in Hematological Cancers Reveal Predominance of Actinomyces and Rothia Species.

The endogenous microbiome of healthy individuals in oral cavities is diverse, representing over 700 bacterial species. Imbalance in oral and gut microbiome composition and associated gene expression has been linked to different forms of hematological (blood) cancers. Our objective is to compare oral microbiome profiles of patients with blood cancers (BC group: N = 39 patients, n = 124 oral samples) to those of healthy control subjects (HC group: N = 27 subjects, n = 100 oral samples). Saliva samples and swabs of buccal mucosa, supragingival plaque, and tongue were collected from blood cancer patients and healthy controls. Next-generation sequencing (16S-rRNA gene V3-V4 region) was used to determine the relative abundance of bacterial taxa present at the genus and species levels. Differences in oral microbiome beta-diversity were determined using multivariate permutational analysis of variance (PERMANOVA). Linear discriminant analysis (LDA) effect size (LEfSe) analysis was performed to identify differentiating bacterial taxa in pairwise comparisons. The PATRICv3.6.7 online tool was used to determine the predominance of potential pathogenicity in the BC group. The oral microbiome beta-diversities of the BC and HC groups differed and corresponded to a reduced alpha-diversity in the BC group. LEfSe analysis showed significant LDA scores for Actinomyces and Rothia spp., differentiating the BC group from the HC group. In silico analysis using PATRICv3.6.7 demonstrated that the groups of bacteria possessing traits of "antibiotic resistance", "oral pathogen", and "virulence" was enriched in the BC group. Although 56% of the BC patients received antibiotics within two weeks of the oral bacterial sampling, Actinomyces genus remained the top differentiating feature in the BC group regardless of the administration of antibiotics, while Rothia dentocariosa was detected as the top differentiating feature in the BC patients who did not receive antibiotics, but not in those who received antibiotics. Further investigation is needed to better understand the interactions of certain oral species with the host immune system to better characterize clinically relevant associations with hematological cancers.

Bacteremia associated with toothbrushing and dental extraction.

BACKGROUND: Antibiotic prophylaxis recommendations for the prevention of infective endocarditis are based in part on studies of bacteremia from dental procedures, but toothbrushing may pose a greater threat. The purpose of this study was to compare the incidence, duration, nature, and magnitude of endocarditis-related bacteremia from single-tooth extraction and toothbrushing and to determine the impact of amoxicillin prophylaxis on single-tooth extraction. METHODS AND RESULTS: In this double-blind, placebo-controlled study, 290 subjects were randomized to (1) toothbrushing, (2) single-tooth extraction with amoxicillin prophylaxis, or (3) single-tooth extraction with identical placebo. Blood was drawn for bacterial culturing and identification at 6 time points before, during, and after these interventions. The focus of our analysis was on bacterial species reported to cause infective endocarditis. We identified 98 bacterial species, 32 of which are reported to cause endocarditis. Cumulative incidence of endocarditis-related bacteria from all 6 blood draws was 23%, 33%, and 60% for the toothbrushing, extraction-amoxicillin, and extraction-placebo groups, respectively (P<0.0001). Significant differences were identified among the 3 groups at draws 2, 3, 4, and 5 (all P<0.05). Amoxicillin resulted in a significant decrease in positive cultures (P<0.0001). CONCLUSIONS: Although amoxicillin has a significant impact on bacteremia resulting from a single-tooth extraction, given the greater frequency for oral hygiene, toothbrushing may be a greater threat for individuals at risk for infective endocarditis.

Diverse and novel oral bacterial species in blood following dental procedures.

We identified oral bacterial species in blood cultures following single-tooth extraction and tooth brushing. Sequence analysis of 16S rRNA genes identified 98 different bacterial species recovered from 151 bacteremic subjects. Of interest, 48 of the isolates represented 19 novel species of Prevotella, Fusobacterium, Streptococcus, Actinomyces, Capnocytophaga, Selenomonas, and Veillonella.

Concordance of HOMIM and HOMINGS technologies in the microbiome analysis of clinical samples.

BACKGROUND: Over 700 bacterial species reside in human oral cavity, many of which are associated with local or distant site infections. Extensive characterization of the oral microbiome depends on the technologies used to determine the presence and proportions of specific bacterial species in various oral sites. OBJECTIVE: The objective of this study was to compare the microbial composition of dental plaque at baseline using Human Oral Microbe Identification Microarray (HOMIM) and Human Oral Microbe Identification using Next Generation Sequencing (HOMINGS) technologies, which are based on 16S rRNA. METHODS: Dental plaque samples were collected from 96 patients at baseline prior to a dental procedure involving manipulation of gingival tissues. The samples were surveyed for 293 and 597 oral bacterial species via HOMIM and HOMINGS, respectively, based on 16S rRNA gene sequences. We determined the concordance between the two technologies for common species. Genus level analysis was performed using HOMINGS-specific genus identification capabilities. RESULTS: HOMINGS detected twice the number of species in the same dental plaque samples compared to HOMIM. For the species detected by both HOMIM and HOMINGS, there was no difference in relative proportions of overall bacterial composition at the species, genus or phylum levels. Additionally, there was no difference in relative proportion for total species per patient between the two technologies. CONCLUSION: HOMINGS significantly expanded oral bacterial species identification compared to HOMIM. The genus and species probes, combined in HOMINGS, provided a more comprehensive representation of oral bacterial community, critical for future characterization of oral microbes in distant site infections.

The role of oral microbial colonization in ventilator-associated pneumonia.

The present article reviews the association between microbial colonization of the oral cavity and the lungs in critically ill patients that develop ventilator-associated pneumonia (VAP) in the intensive care unit (ICU) setting. The risk factors and microorganisms associated with VAP are presented. The role of oral colonization of VAP-associated pathogens (VAP-AP) in the development of VAP is examined. We explore the potential factors involved in oral colonization of VAP-AP, which are atypical bacteria for the oral cavity. Strategies for the prevention or moderation of oral colonization of VAP-AP have had limited success. We need a deeper understanding of the pathophysiology of VAP in order to reduce the morbidity, mortality, and cost from this common complication in ICU medicine and surgery.

Microarray analyses of oral punch biopsies from acute myeloid leukemia (AML) patients treated with chemotherapy.

OBJECTIVE: Understanding the pathogenesis of chemotherapy-induced oral mucositis (CIOM) is vital to develop therapies for this common, dose-limiting side effect of cancer treatment. We investigated molecular events in CIOM from buccal mucosa tissue collected before and 2 days after chemotherapy from patients with acute myeloid leukemia (AML) and healthy controls by microarray analysis. METHODS: Microarray analysis was performed using Human Genome U133 Plus 2.0 Array on buccal mucosa punch biopsies from patients with AML before (n = 4) or after chemotherapy (n = 4), and from healthy controls (n = 3). Following Robust Multichip Average (RMA) normalization, we applied Linear Models for Microarray data (LIMMA) and Significance Analysis of Microarrays (SAM) for data analysis using the TM4/TMeV v4.5.1 program. RESULTS: LIMMA and SAM identified genes potentially affected by the presence of AML, including homeodomain-interacting protein kinase 1 (HIPK1), mex-3 homolog D (MEX3D), and genes potentially affected by chemotherapy, including argininosuccinate synthase 1 (ASS1), notch homolog 1 (NOTCH1), zinc transporter ZIP6 (SLC39A6), and TP53-regulated inhibitor of apoptosis 1 (TRIAP1). The expression of 2 genes with potential biological significance in oral mucositis, ASS1 and SLC39A6 (alias LIV-1), was confirmed by quantitative real-time reverse transcriptase-polymerase chain reaction (qRT-PCR). CONCLUSIONS: Our results suggest that AML-specific deregulated immune responses and inflammatory tissue damage to the oral mucosa caused by chemotherapy may not be overcome by the natural cellular repair processes and therefore contribute to CIOM.

Treatment of major laparoscopic bile duct injury: a long-term follow-up result.

The goal of this study is to present the multiple institutions experience comparing the outcome of management between initial laparoscopic cholecystectomy (LC) surgeon and specialist as well as the outcome of different operative procedures to major bile duct injury (BDI) after LC. We have retrospectively collected data of 77 cases of perioperatively detected major BDI in LC at 15 general surgical institutions from 1997 to 2007. We classified 42 cases treated by an experienced biliary surgeon as Group A and 35 cases treated by the initial LC surgeon as Group B. Forty-eight cases were treated with duct-to-duct anastomosis as Group C and 29 cases were treated with Roux-en-Y choledochojejunostomy as Group D. The median duration of follow-up was 62 months. The outcome of groups was compared. In Group A, 7 of 42 (16.7%) patients developed a failure. Two of seven (28.6%) patients were treated by a secondary operation. In Group B, 24 of 35 (68.6%) patients developed a failure. Seventeen of 24 (70.8%) patients were treated by a secondary operation. One of 35 (2.85%) patients died. The significant differences were observed in failure and secondary operations (16.7 vs 68.6%, P < 0.01 and 28.6 vs 70.8%, P < 0.01). There is no significant difference Group C and Group D in failure rate (28.5 vs 11.7%, P > 0.05). A multiple institutional cooperative methodology between the local surgical institution and tertiary care centers provided a good way to limit further operations, failure. The reconstructive strategy is important and should be selected according to the type of injury and the diagnosed status of major BDI.

Molecular methodology to assess the impact of cancer chemotherapy on the oral bacterial flora: a pilot study.

OBJECTIVE: This pilot study determined the profile of the oral bacterial flora in an outpatient cancer population before and after chemotherapy using molecular techniques. STUDY DESIGN: We recruited 9 newly diagnosed breast cancer patients scheduled for induction chemotherapy. All were seen immediately before chemotherapy, and 7 to 14 days later. At both visits, we performed oral evaluations and obtained mucositis grading (with the World Health Organization [WHO] scale), absolute neutrophil counts (ANC), and bacterial samples from the buccal mucosa. Bacterial DNA was isolated, and 16S ribosomal RNA gene clonal libraries were constructed. Sequences of genes in the library were used to determine species identity by comparison to known sequences. RESULTS: After chemotherapy, WHO scores of 0 and 1 were in 3 and 6 patients, respectively, and mean ANC (+/-SD) dropped from 3326 +/- 463 to 1091 +/- 1082 cells/mm(3). From pre- and post-chemotherapy samples, 41 species were detected, with a predominance of Gemella haemolysans and Streptococcus mitis. More than 85% of species have not been previously identified in chemotherapy patients. Seven species appeared exclusively before chemotherapy and 25 after chemotherapy. After chemotherapy, the number of species per patient increased by a mean of 2.6 (SD = 4.7, P = .052). CONCLUSION: We identified species not previously identified in chemotherapy patients. Our results suggest a shift to a more complex oral bacterial profile in patients undergoing cancer chemotherapy.

Poor oral hygiene as a risk factor for infective endocarditis-related bacteremia.

BACKGROUND: Infective endocarditis (IE) often is caused by bacteria that colonize teeth. The authors conducted a study to determine if poor oral hygiene or dental disease are risk factors for developing bacteremia after toothbrushing or single-tooth extraction. METHODS: One hundred ninety-four participants in a study were in either a toothbrushing group or a single-tooth extraction with placebo group. The authors assessed the participants' oral hygiene, gingivitis and periodontitis statuses. They assayed blood samples obtained before, during and after the toothbrushing or extraction interventions for IE-associated bacteria. RESULTS: The authors found that oral hygiene and gingival disease indexes were associated significantly with IE-related bacteremia after toothbrushing. Participants with mean plaque and calculus scores of 2 or greater were at a 3.78- and 4.43-fold increased risk of developing bacteremia, respectively. The presence of generalized bleeding after toothbrushing was associated with an almost eightfold increase in risk of developing bacteremia. There was no significant association between any of the measures of periodontal disease and the incidence of bacteremia after toothbrushing. The oral hygiene or disease status of a tooth was not significantly associated with bacteremia after its extraction. CONCLUSION: Bacteremia after toothbrushing is associated with poor oral hygiene and gingival bleeding after toothbrushing. CLINICAL IMPLICATIONS: Improvements in oral hygiene may reduce the risk of developing IE.

Systemic host immuno-inflammatory response to dental extractions and periodontitis.

OBJECTIVES: Little is known about the host immuno-inflammatory response to dental extractions. The purpose of this pilot clinical study was to explore the effect of both periodontitis and dental extractions on the host systemic immuno-inflammatory response. STUDY DESIGN: We recruited and collected baseline blood samples on 41 essentially healthy patients. A subset of 22 subjects underwent single (n = 11) or multiple (n = 11) tooth extractions with additional blood samples taken at 1 hour following single tooth extraction and at 8 and 24 hours following multiple tooth extractions. Samples were used for determination of an array of 12 cytokines known to play key roles in innate and adaptive immunity. RESULTS: There was no significant difference in cytokine levels between the pre- and post-tooth extraction samples for either extraction group for the time points measured. Nor was there a positive relationship between the level of any of the cytokines and periodontal disease status as measured by mean probing depths and other periodontal disease parameters. CONCLUSION: Our pilot data suggest that the body is well adjusted to deal with the inflammation and bacteremia associated with dental extractions and periodontal disease.

Identification of oral bacteria in blood cultures by conventional versus molecular methods.

OBJECTIVE: The purpose of this study was to compare two different methods of identifying oral bacteria from blood samples after dental extractions. STUDY DESIGN: Blood cultures were taken before, during, and after a single tooth extraction in 30 subjects and cultured using aerobic and anaerobic Bactec media. Positive cultures from 22 subjects were subcultured on selective and nonselective media, resulting in 58 isolates. Bacterial identification was performed by biochemical analysis and sequence analysis of 16S rRNA gene. RESULTS: Of the 58 isolates, only 10 (17%) were the same species by both methods. Thirty-two (55%) belonged to the same genus but different species, and 16 (28%) showed no correlation at all. There were 31 and 40 diverse species by the biochemical and the sequencing methods, respectively. Streptococci were the dominant species. CONCLUSIONS: DNA sequencing results in more accurate identification and a more diverse population of bacteria from bacteremia following dental extractions.