The capsule of Bacillus anthracis protects it from the bactericidal activity of human defensins and other cationic antimicrobial peptides.

During infection, Bacillus anthracis bacilli encounter potent antimicrobial peptides (AMPs) such as defensins. We examined the role that B. anthracis capsule plays in protecting bacilli from defensins and other cationic AMPs by comparing their effects on a fully virulent encapsulated wild type (WT) strain and an isogenic capsule-deficient capA mutant strain. We identified several human defensins and non-human AMPs that were capable of killing B. anthracis. The human alpha defensins 1-6 (HNP-1-4, HD-5-6), the human beta defensins 1-4 (HBD-1-4), and the non-human AMPs, protegrin, gramicidin D, polymyxin B, nisin, and melittin were all capable of killing both encapsulated WT and non-encapsulated capA mutant B. anthracis. However, non-encapsulated capA mutant bacilli were significantly more susceptible than encapsulated WT bacilli to killing by nearly all of the AMPs tested. We demonstrated that purified capsule bound HBD-2, HBD-3, and HNP-1 in an electrophoretic mobility shift assay. Furthermore, we determined that the capsule layer enveloping WT bacilli bound and trapped HBD-3, substantially reducing the amount reaching the cell wall. To assess whether released capsule might also play a protective role, we pre-incubated HBD-2, HBD-3, or HNP-1 with purified capsule before their addition to non-encapsulated capA mutant bacilli. We found that free capsule completely rescued the capA mutant bacilli from killing by HBD-2 and -3 while killing by HNP-1 was reduced to the level observed with WT bacilli. Together, these results suggest an immune evasion mechanism by which the capsule, both that enveloping the bacilli and released fragments, contributes to virulence by binding to and inhibiting the antimicrobial activity of cationic AMPs.

Burkholderia pseudomallei JW270 Is Lethal in the Madagascar Hissing Cockroach Infection Model and Can Be Utilized at Biosafety Level 2 to Identify Putative Virulence Factors.

Burkholderia pseudomallei, the causative agent of melioidosis, is classified by the CDC as a tier 1 select agent, and work involving it must be performed in a biosafety level 3 (BSL-3) laboratory. Three BSL-2 surrogate strains derived from B. pseudomallei 1026b, a virulent clinical isolate, have been removed from the CDC select agent list. These strains, Bp82, B0011, and JW270, are highly attenuated in rodent models of melioidosis and cannot be utilized to identify virulence determinants because of their high 50% lethal dose (LD50). We previously demonstrated that the Madagascar hissing cockroach (MHC) is a tractable surrogate host to study the innate immune response against Burkholderia. In this study, we found that JW270 maintains its virulence in MHCs. This surprising result indicates that it may be possible to identify potential virulence genes in JW270 by using MHCs at BSL-2. We tested this hypothesis by constructing JW270 mutations in genes that are required (hcp1) or dispensable (hcp2) for B. pseudomallei virulence in rodents. JW270 Δhcp1 was avirulent in MHCs and JW270 Δhcp2 was virulent, suggesting that MHCs can be used at BSL-2 for the discovery of important virulence factors. JW270 ΔBPSS2185, a strain harboring a mutation in a type IV pilin locus (TFP8) required for full virulence in BALB/c mice, was also found to be attenuated in MHCs. Finally, we demonstrate that the hmqA-G locus, which encodes the production of a family of secondary metabolites called 4-hydroxy-3-methyl-2-alkylquinolines, is important for JW270 virulence in MHCs and may represent a novel virulence determinant.

Clinical Features of Patients Hospitalized for All Routes of Anthrax, 1880-2018: A Systematic Review.

BACKGROUND: Anthrax is a toxin-mediated zoonotic disease caused by Bacillus anthracis, with a worldwide distribution recognized for millennia. Bacillus anthracis is considered a potential biowarfare agent. METHODS: We completed a systematic review for clinical and demographic characteristics of adults and children hospitalized with anthrax (cutaneous, inhalation, ingestion, injection [from contaminated heroin], primary meningitis) abstracted from published case reports, case series, and line lists in English from 1880 through 2018, assessing treatment impact by type and severity of disease. We analyzed geographic distribution, route of infection, exposure to anthrax, and incubation period. RESULTS: Data on 764 adults and 167 children were reviewed. Most cases reported for 1880 through 1915 were from Europe; those for 1916 through 1950 were from North America; and from 1951 on, cases were from Asia. Cutaneous was the most common form of anthrax for all populations. Since 1960, adult anthrax mortality has ranged from 31% for cutaneous to 90% for primary meningitis. Median incubation periods ranged from 1 day (interquartile range [IQR], 0-4) for injection to 7 days (IQR, 4-9) for inhalation anthrax. Most patients with inhalation anthrax developed pleural effusions and more than half with ingestion anthrax developed ascites. Treatment and critical care advances have improved survival for those with systemic symptoms, from approximately 30% in those untreated to approximately 70% in those receiving antimicrobials or antiserum/antitoxin. CONCLUSIONS: This review provides an improved evidence base for both clinical care of individual anthrax patients and public health planning for wide-area aerosol releases of B. anthracis spores.

Human Innate Immune Cells Respond Differentially to Poly-γ-Glutamic Acid Polymers from Bacillus anthracis and Nonpathogenic Bacillus Species.

The poly-γ-glutamic acid (PGA) capsule produced by Bacillus anthracis is composed entirely of d-isomer glutamic acid, whereas nonpathogenic Bacillus species produce mixed d-, l-isomer PGAs. To determine if B. anthracis PGA confers a pathogenic advantage over other PGAs, we compared the responses of human innate immune cells to B. anthracis PGA and PGAs from nonpathogenic B. subtilis subsp. chungkookjang and B. licheniformis Monocytes and immature dendritic cells (iDCs) responded differentially to the PGAs, with B. anthracis PGA being least stimulatory and B. licheniformis PGA most stimulatory. All three elicited IL-8 and IL-6 from monocytes, but B. subtilis PGA also elicited IL-10 and TNF-α, whereas B. licheniformis PGA elicited all those plus IL-1ß. Similarly, all three PGAs elicited IL-8 from iDCs, but B. subtilis PGA also elicited IL-6, and B. licheniformis PGA elicited those plus IL-12p70, IL-10, IL-1ß, and TNF-α. Only B. licheniformis PGA induced dendritic cell maturation. TLR assays also yielded differential results. B. subtilis PGA and B. licheniformis PGA both elicited more TLR2 signal than B. anthracis PGA, but only responses to B. subtilis PGA were affected by a TLR6 neutralizing Ab. B. licheniformis PGA elicited more TLR4 signal than B. anthracis PGA, whereas B. subtilis PGA elicited none. B. anthracis PGA persisted longer in high m.w. form in monocyte and iDC cultures than the other PGAs. Reducing the m.w. of B. anthracis PGA reduced monocytes' cytokine responses. We conclude that B. anthracis PGA is recognized less effectively by innate immune cells than PGAs from nonpathogenic Bacillus species, resulting in failure to induce a robust host response, which may contribute to anthrax pathogenesis.

Clindamycin Protects Nonhuman Primates Against Inhalational Anthrax But Does Not Enhance Reduction of Circulating Toxin Levels When Combined With Ciprofloxacin.

BACKGROUND: Inhalational anthrax is rare and clinical experience limited. Expert guidelines recommend treatment with combination antibiotics including protein synthesis-inhibitors to decrease toxin production and increase survival, although evidence is lacking. METHODS: Rhesus macaques exposed to an aerosol of Bacillus anthracis spores were treated with ciprofloxacin, clindamycin, or ciprofloxacin + clindamycin after becoming bacteremic. Circulating anthrax lethal factor and protective antigen were quantitated pretreatment and 1.5 and 12 hours after beginning antibiotics. RESULTS: In the clindamycin group, 8 of 11 (73%) survived demonstrating its efficacy for the first time in inhalational anthrax, compared to 9 of 9 (100%) with ciprofloxacin, and 8 of 11 (73%) with ciprofloxacin + clindamycin. These differences were not statistically significant. There were no significant differences between groups in lethal factor or protective antigen levels from pretreatment to 12 hours after starting antibiotics. Animals that died after clindamycin had a greater incidence of meningitis compared to those given ciprofloxacin or ciprofloxacin + clindamycin, but numbers of animals were very low and no definitive conclusion could be reached. CONCLUSION: Treatment of inhalational anthrax with clindamycin was as effective as ciprofloxacin in the nonhuman primate. Addition of clindamycin to ciprofloxacin did not enhance reduction of circulating toxin levels.

Elevated White Blood Cell Count Resultant Atherogenesis is Associated With Panoramic-Imaged Carotid Plaque.

PURPOSE: Atherosclerotic plaques develop as a result of a low-grade, chronic, systemic inflammatory response to the injury of endothelial cells arising from lipid deposition within the intima. Increased white blood cell count (WBCC) is both a validated "biologic marker" of the extent of this inflammatory process and a key participant in the development of subsequent atherosclerotic ischemic heart disease manifesting as myocardial infarction. We sought to determine if calcified carotid artery plaque (CCAP) on a panoramic image (PI), also a validated risk indicator of future myocardial infarction, is associated with increased WBCC. PATIENTS AND METHODS: We retrospectively evaluated the PI and medical records of White male military veterans aged 55 years and older treated by a VA dental service. Established were 2 cohorts of patients, 50 having plaques (CCAP+) and 50 without plaques (CCAP-). Predictor variable was CCAP+; outcome variable was WBCC. Bootstrapping analysis determined the differences in mean WBCCs between groups. Statistical significance set at ≤ 0.05. RESULTS: The study group, (mean age 74; range 59 to 91 years) demonstrated a mean WBCC of 8,062 per mm3. The control group, (mean age 72 range; 57 to 94) evidenced a mean WBCC of 7,058 per mm3. Bootstrapping analysis of WBCC values demonstrated a significant (P = .012) difference (95% confidence interval of difference of mean, -806, 742; observed effect size, 1004) between groups. CONCLUSIONS: The presence of CCAP demonstrated on PIs of older Caucasian men is associated with elevated WBCC. Concomitant presence of CCAP on PI and increased WBCC (≥7,800 per mm3) amplifies need for medical consultation before intravenous anesthesia and maxillofacial surgical procedures.

Use of Anthrax Vaccine in the United States: Recommendations of the Advisory Committee on Immunization Practices, 2019.

This report updates the 2009 recommendations from the CDC Advisory Committee on Immunization Practices (ACIP) regarding use of anthrax vaccine in the United States (Wright JG, Quinn CP, Shadomy S, Messonnier N. Use of anthrax vaccine in the United States: recommendations of the Advisory Committee on Immunization Practices [ACIP)], 2009. MMWR Recomm Rep 2010;59[No. RR-6]). The report 1) summarizes data on estimated efficacy in humans using a correlates of protection model and safety data published since the last ACIP review, 2) provides updated guidance for use of anthrax vaccine adsorbed (AVA) for preexposure prophylaxis (PrEP) and in conjunction with antimicrobials for postexposure prophylaxis (PEP), 3) provides updated guidance regarding PrEP vaccination of emergency and other responders, 4) summarizes the available data on an investigational anthrax vaccine (AV7909), and 5) discusses the use of anthrax antitoxins for PEP. Changes from previous guidance in this report include the following: 1) a booster dose of AVA for PrEP can be given every 3 years instead of annually to persons not at high risk for exposure to Bacillus anthracis who have previously received the initial AVA 3-dose priming and 2-dose booster series and want to maintain protection; 2) during a large-scale emergency response, AVA for PEP can be administered using an intramuscular route if the subcutaneous route of administration poses significant materiel, personnel, or clinical challenges that might delay or preclude vaccination; 3) recommendations on dose-sparing AVA PEP regimens if the anthrax vaccine supply is insufficient to vaccinate all potentially exposed persons; and 4) clarification on the duration of antimicrobial therapy when used in conjunction with vaccine for PEP.These updated recommendations can be used by health care providers and guide emergency preparedness officials and planners who are developing plans to provide anthrax vaccine, including preparations for a wide-area aerosol release of B. anthracis spores. The recommendations also provide guidance on dose-sparing options, if needed, to extend the supply of vaccine to increase the number of persons receiving PEP in a mass casualty event.

Formaldehyde and Glutaraldehyde Inactivation of Bacterial Tier 1 Select Agents in Tissues.

For safety, designated Select Agents in tissues must be inactivated and viability tested before the tissue undergoes further processing and analysis. In response to the shipping of samples of "inactivated" Bacillus anthracis that inadvertently contained live spores to nonregulated entities and partners worldwide, the Federal Register now mandates in-house validation of inactivation procedures and standardization of viability testing to detect live organisms in samples containing Select Agents that have undergone an inactivation process. We tested and validated formaldehyde and glutaraldehyde inactivation procedures for animal tissues infected with virulent B. anthracis, Burkholderia pseudomallei, Francisella tularensis, and Yersinia pestis. We confirmed that our fixation procedures for tissues containing these Tier 1 Select Agents resulted in complete inactivation and that our validated viability testing methods do not interfere with detection of live organisms. Institutions may use this work as a guide to develop and conduct their own testing to comply with the policy.

Severe Sleep Apnea Associated With Increased Systemic Inflammation and Decreased Serum Bilirubin.

PURPOSE: Obstructive sleep apnea hypopnea syndrome (OSAHS) among older men has been associated with increased systemic inflammation, as evidenced by an increased neutrophil/lymphocyte ratio (NLR) and provocation of coronary artery atherosclerosis, potentially resulting in myocardial infarction (MI). The total serum bilirubin levels (TSBLs; formed primarily from senescent red blood cells via the catabolic pathway in the reticuloendothelial system) at the higher end of the normal reference range are anti-inflammatory. However, at the lower end of the physiologic range, they have been associated with increased adverse vascular events. We compared the relationship between NLR and TSBL among subjects with "severe" OSAHS. MATERIALS AND METHODS: We used a retrospective, cross-sectional study design. The electronic medical records of older male subjects (age range, 55 to 74 years) with "severe" OSAHS treated by the dental service (January 1, 2017 to December 31, 2017) were examined. The predictor variable was the NLR, and the outcome variable was the TSBL; both were analyzed using continuous scales. Spearman's rank order correlation analysis explicated the relationship between the NLR and TBSL. Traditional proatherogenic risk factors (ie, age, body mass index, hypertension, hyperlipidemia, diabetes) were evaluated for independence using descriptive and logistic regression analysis. Significance was set at P = .05 for all tests. RESULTS: A total sample size of 47 subjects (mean age, 63.74 ± 4.12 years) was enrolled in the present study. The Spearman rank order correlation analysis determined that the NLR is significantly (P = .038) and inversely related to the TSBL (rs = -0.304). CONCLUSIONS: Older men with "severe" OSAHS demonstrated an inverse relationship between NLR and TSBL. This combination of a heightened severity marker of systemic inflammation (ie, elevated NLR) and an indicator of amplified atherosclerotic activity (ie, diminished TSBL) will identify patients potentially at increased risk of future MI and the need for cardiovascular evaluation.

Severe Obstructive Sleep Apnea With Imaged Carotid Plaque Is Significantly Associated With Systemic Inflammation.

PURPOSE: Persons with obstructive sleep apnea (OSA) are at heightened risk of myocardial infarction (MI) and stroke caused by adiposity and intermittent hypoxia, which provoke proinflammatory cytokines to induce systemic and vascular inflammation, resulting in endothelial dysfunction and development of atherosclerotic plaque. This study compared levels of systemic inflammation, as indexed by the neutrophil-to-lymphocyte ratio (NLR), between groups of patients with severe OSA with and without carotid artery calcified plaque (CACP+ and CACP-, respectively) on their panoramic image (PI). MATERIALS AND METHODS: This study had a retrospective cross-sectional study design. Medical records and PIs of men with severe OSA treated by the dental service (January 1, 2017 to December 31, 2017) were reviewed. The predictor variable was the presence or absence of CACP on PIs and the outcome variable was NLR. The t test was used to analyze differences in mean NLRs between groups. Atherogenic risk factors (age, body mass index, hypertension, and diabetes) were assessed for independence by descriptive and logistic regression analyses. Significance set at .05 for all tests. RESULTS: The study group (n = 39) of patients with CACP+ (mean age, 63 ± 7.4 yr) showed a mean NLR of 3.09 ± 1.42. The control group (n = 46) of patients with CACP- (mean age, 62 ± 6.8 yr) showed a mean NLR of 2.10 ± 0.58. The difference between groups was significant (P < .001). Logistic regression for NLR and CACP failed to show meaningful correlations with covariates. CONCLUSION: Older men with severe OSA and carotid atheromas on PIs show substantially greater systemic inflammation measured by NLRs. The combination of severe OSA, atheroma formation, and markedly increased NLR suggests a higher risk of MI and stroke and greater need for cardiovascular and cerebrovascular evaluation.

Severity of Obstructive Sleep Apnea Is Positively Associated With the Presence of Carotid Artery Atheromas.

PURPOSE: Hypoxemia and hypertension caused by obstructive sleep apnea (OSA) often result in atherosclerosis of the carotid and coronary vessels and heightened risk of stroke and myocardial infarction (MI). Therefore, this study investigated whether severity of OSA, based on the apnea-hypopnea index (AHI), is associated with the presence of calcified carotid artery (atherosclerotic) plaque (CCAP) seen on panoramic images (PIs). MATERIALS AND METHODS: Using a cross-sectional study design, the electronic medical records and PIs of all male patients referred from the sleep medicine service to the dental service from 2010 through 2016 were reviewed. The predictor variable was the patients' OSA intensity level as defined by the American Academy of Sleep Medicine based on the AHI score. The outcome variable was the presence of CCAP on the PI. Other variables of interest, that is, demographic and atherogenic risk factors (age, body mass index, diabetes, hypertension, and hyperlipidemia), were included in a multivariate analysis to assess the association of OSA with CCAP. RESULTS: The study sample consisted of 108 men (mean age, 54.7 ± 13.5 yr). Approximately one third (n = 33; 30.6%) presented with CCAP and this group was significantly older with greater odds of co-diagnosis of diabetes (P < .05). Patients with more "severe" OSA showed significantly greater odds of having CCAP on their PIs compared with those with "milder" OSA (odds ratio = 1.035; 95% confidence interval, 1.008-1.062; P = .010) when adjusted for confounders. CONCLUSION: There is a significant association between severity of OSA and the presence of CCAP visible on PI. These atherosclerotic plaques are "risk factors" for stroke and "risk indicators" for future MI; therefore, clinicians providing corrective airway surgery for these patients and noting concomitant CCAP on PI should refer these patients for a thorough cerebrovascular and cardiovascular workup.

Positive Association Between Neutrophil-Lymphocyte Ratio and Presence of Panoramically Imaged Carotid Atheromas Among Men.

PURPOSE: Heightened levels of systemic inflammation documented by increased neutrophil-to-lymphocyte ratios (NLRs) characterize a robust atherosclerosis processes evidenced by carotid and coronary artery plaques at ultrasound and angiography with associated strokes and myocardial infarctions (MIs). Therefore, this study investigated whether calcified carotid artery plaques (CCAPs) on panoramic images (PIs), known to herald future stroke and MI, are associated with increased NLRs. MATERIALS AND METHODS: Using a cross-sectional study design, electronic medical records and PIs of non-Hispanic white men at least 55 years old who were treated by the dental service (January 1, 2017 to December 31, 2017) were retrieved. Two groups of patients (n = 50 per group) with plaque (CCAP+) and without plaque (CCAP-) were constituted. The predictor variable was CCAP+ and the outcome variable was the NLR. A t test analyzed the differences in mean NLRs between groups. Other variables of interest, that is, atherogenic risk factors (hypertension, hyperlipidemia, and diabetes mellitus), were included in a logistic regression analysis to assess their influence on the association of CCAP with the NLR. Significance was set at .05 for all tests. RESULTS: The study group of 50 men with CCAP+ (mean age, 71.7 ± 7.47 yr) evidenced a mean NLR of 3.07 ± 1.43. The control group of 50 men with CCAP- (mean age, 69.8 ± 9.29 yr) evidenced a mean NLR of 2.13 ± 0.68. A t test analysis comparison showed a significant (P = .00007) difference (95% confidence interval, 0.49-1.39). Logistic regression failed to show any relevant relation of the NLR with the covariate and other variables of interest. CONCLUSION: There is a strong association between CCAP+ in older non-Hispanic white men and extent of systemic inflammation as evidenced by increased NLRs. These plaques are "risk factors or indicators" for future stroke and MI. Therefore, maxillofacial surgeons providing care for patients with CCAP+ should consider referring them for a comprehensive cerebrovascular and cardiovascular workup.

Galactosylation of the Secondary Cell Wall Polysaccharide of Bacillus anthracis and Its Contribution to Anthrax Pathogenesis.

Bacillus anthracis, the causative agent of anthrax disease, elaborates a secondary cell wall polysaccharide (SCWP) that is essential for bacterial growth and cell division. B. anthracis SCWP is comprised of trisaccharide repeats with the structure, [→4)-ß-ManNAc-(1→4)-ß-GlcNAc(O3-α-Gal)-(1→6)-α-GlcNAc(O3-α-Gal, O4-ß-Gal)-(1→]6-12 The genes whose products promote the galactosylation of B. anthracis SCWP are not yet known. We show here that the expression of galE1, encoding a UDP-glucose 4-epimerase necessary for the synthesis of UDP-galactose, is required for B. anthracis SCWP galactosylation. The galE1 mutant assembles surface (S) layer and S layer-associated proteins that associate with ketal-pyruvylated SCWP via their S layer homology domains similarly to wild-type B. anthracis, but the mutant displays a defect in γ-phage murein hydrolase binding to SCWP. Furthermore, deletion of galE1 diminishes the capsulation of B. anthracis with poly-d-γ-glutamic acid (PDGA) and causes a reduction in bacterial virulence. These data suggest that SCWP galactosylation is required for the physiologic assembly of the B. anthracis cell wall envelope and for the pathogenesis of anthrax disease.IMPORTANCE Unlike virulent Bacillus anthracis isolates, B. anthracis strain CDC684 synthesizes secondary cell wall polysaccharide (SCWP) trisaccharide repeats without galactosyl modification, exhibits diminished growth in vitro in broth cultures, and is severely attenuated in an animal model of anthrax. To examine whether SCWP galactosylation is a requirement for anthrax disease, we generated variants of B. anthracis strains Sterne 34F2 and Ames lacking UDP-glucose 4-epimerase by mutating the genes galE1 and galE2 We identified galE1 as necessary for SCWP galactosylation. Deletion of galE1 decreased the poly-d-γ-glutamic acid (PDGA) capsulation of the vegetative form of B. anthracis and increased the bacterial inoculum required to produce lethal disease in mice, indicating that SCWP galactosylation is indeed a determinant of anthrax disease.

Males With Rheumatoid Arthritis Often Evidence Carotid Atheromas on Panoramic Imaging: A Risk Indicator of Future Cardiovascular Events.

PURPOSE: Males with rheumatoid arthritis (RA) are at an exceedingly high risk of adverse intraoperative ischemic events, given the role of systemic inflammation in the atherogenic process. We hypothesized that their panoramic images would demonstrate calcified carotid artery atheromas (CCAPs) significantly more often than those from a general population of similarly aged men. PATIENTS AND METHODS: We implemented a retrospective observational study. The sample was composed of male patients older than 55 years of age who had undergone panoramic imaging studies. The predictor variable was the diagnosis of RA confirmed by a positive rheumatoid factor (RF) titer, and the outcome variable was the prevalence rate of CCAPs. The other major study variable was the level of RF among the patients evidencing CCAPs. The prevalence of CCAPs among the patients with RA was then compared with that of a historical general population of similarly aged men. Descriptive and bivariate statistics were computed, and the P value was set at .05. RESULTS: Of the 100 men (mean age 69.89 ± 8.927 years) with RA, 29 (29%; mean age 72.10 ± 7.68 years) had atheromas (CCAP+). Of these 29 men, 25 (86%; mean age 71.88 ± 7.43 years) had a RF titer of ≥41 IU/mL, twice that of normal. A statistically significant (P < .05) association was found between a diagnosis of RA and the presence of an atheroma on the panoramic image compared with the 3% rate found in the historical cohort. CONCLUSIONS: The results of the present study suggest that CCAP, a risk indicator of future adverse cardiovascular events, is frequently seen on panoramic images of male patients with RA and that these individuals routinely manifest high titer levels of RF, a biologic marker of inflammation. Oral and maxillofacial surgeons planning surgery for male patients with RA must be uniquely vigilant for the presence of these lesions.

Prevalence of Panoramically Imaged Carotid Atheromas in Alcoholic Patients With Chronic Pancreatitis and Comorbid Diabetes.

PURPOSE: Men with alcohol-related chronic pancreatitis (ARCP) resulting in type 3c diabetes mellitus (DM) are at a uniquely elevated risk of adverse ischemic events given the role of inflammation in both the underlying disease processes and atherosclerosis. We hypothesized that their panoramic images would show a prevalence of calcified carotid artery atheromas (calcified carotid artery plaques [CCAPs]) significantly more often than a general population of similarly aged men. PATIENTS AND METHODS: We implemented a retrospective observational study. The sample was composed of male patients older than 30 years having panoramic images. The predictor variable was a diagnosis of ARCP-DM, and the outcome variable was the prevalence rate of CCAPs. The prevalence of CCAPs among the patients with ARCP-DM was then compared with that of a historical general population composed of similarly aged men. Descriptive and bivariate statistics were computed, and the P value was set at .05. RESULTS: Of the 32 men (mean age, 61.7 ± 11.2 years) with ARCP-DM, 8 (25%) (mean age, 63.3 ± 4.80 years) had atheromas (CCAPs). There was a statistically significant (P < .05) association between a diagnosis of ARCP-DM and the presence of an atheroma on the panoramic image in comparison with the 3% rate manifested by the historical general-population cohort. The presence or absence of classic atherogenic risk factors within the ARCP-DM cohort failed to distinguish between individuals with and individuals without atheroma formation on their panoramic images. CONCLUSIONS: The results of this study suggest that CCAP, a risk indicator for future adverse cardiovascular events, is frequently seen on the panoramic images of male patients with ARCP-DM. Dentists treating male patients with the disorder must be uniquely vigilant for the presence of these lesions.

pH Alkalinization by Chloroquine Suppresses Pathogenic Burkholderia Type 6 Secretion System 1 and Multinucleated Giant Cells.

Burkholderia mallei and B. pseudomallei cause glanders and melioidosis, respectively, in humans and animals. A hallmark of pathogenesis is the formation of granulomas containing multinucleated giant cells (MNGCs) and cell death. These processes depend on type 6 secretion system 1 (T6SS-1), which is required for virulence in animals. We examined the cell biology of MNGC formation and cell death. We found that chloroquine diphosphate (CLQ), an antimalarial drug, inhibits Burkholderia growth, phagosomal escape, and subsequent MNGC formation. This depends on CLQ's ability to neutralize the acid pH because other alkalinizing compounds similarly inhibit escape and MNGC formation. CLQ inhibits bacterial virulence protein expression because T6SS-1 and some effectors of type 3 secretion system 3 (T3SS-3), which is also required for virulence, are expressed at acid pH. We show that acid pH upregulates the expression of Hcp1 of T6SS-1 and TssM, a protein coregulated with T6SS-1. Finally, we demonstrate that CLQ treatment of Burkholderia-infected Madagascar hissing cockroaches (HCs) increases their survival. This study highlights the multiple mechanisms by which CLQ inhibits growth and virulence and suggests that CLQ be further tested and considered, in conjunction with antibiotic use, for the treatment of diseases caused by Burkholderia.

Preventive Dental Treatment Workload/Costs to Mitigate Antiresorptive Bone Medication-related Osteonecrosis Risk.

PURPOSE: To determine the extent of dental disease and associated treatment costs designed to mitigate the risk of medication-related osteonecrosis of the jaws (MRONJ) among older, socially disadvantaged veterans prior to physician's administration of antiresorptive medication for osteoporosis or malignant bone disease. MATERIALS AND METHODS: This prospective study based on over seven years (2008-2015) of data describes the type and volume of disease, treatment, work-load measures, and costs using Veterans Affairs databases. RESULTS: One hundred fifty-two outpatients (94% male, mean age 69 ± 12 years) were referred by physicians for clinical/radiographic examination and treatment. Sixteen had a healthy dentition and 17 were completely edentulous with satisfactory prostheses. Three edentulous patients required prosthesis adjustment, 116 dentate individuals required restoration of carious teeth (mean 6.3 ± 5.7) and multiple quadrant (mean 3.1 ± 1.0) scaling/subgingival curettage. In the latter group, 75 required extractions (mean 6.0 teeth, range 1-23). Clinician's (dentist and dental assistant) costs for providing care and preventive education over the 7-year timespan came to almost $132,700. CONCLUSION: Older veterans requiring initiation of antiresorptive bone medication harbor extensive, untreated dental disease requiring immediate treatment. An appropriate physician-to-dentist referral network and provision of oral care and patient education prior to initiation of medication can potentially moderate the risk of jaw osteonecrosis.

Patients Receiving Parenteral Bisphosphonates for Malignant Disease and Having Developed an Atypical Femoral Fracture Are at Risk of Concomitant Osteonecrosis of the Jaw: An Evidence-Based Review.

PURPOSE: The risk of developing concomitant medication-related osteonecrosis of the jaw (MRONJ) in patients who have sustained an atypical femoral fracture (AFF) in association with parental administration of a bisphosphonate osteoclastic inhibitor medication for malignant disease is unclear. Published data were searched to determine the prevalence of these concomitant adverse medication events, if any. MATERIALS AND METHODS: A systematic review of published case series in the PubMed database was undertaken to ascertain the prevalence of patients having a concomitant history of AFF and MRONJ. The data were analyzed to provide prevalence rates of these events from the literature. RESULTS: Two case series were identified that delineated the risk (25 and 33%, respectively) of concomitant development of MRONJ and AFF in recipients of parenteral bisphosphonate medication administered for malignant disease. CONCLUSION: The published data suggest that approximately 30% of patients receiving parenteral bisphosphonates and having sustained an AFF could develop comorbid MRONJ.