Flagellin-modulated inflammasome pathways characterize the human alveolar macrophage response to Burkholderia pseudomallei, a lung-tropic pathogen.

Melioidosis is an emerging tropical infection caused by inhalation, inoculation, or ingestion of the flagellated, facultatively intracellular pathogen Burkholderia pseudomallei. The melioidosis case fatality rate is often high, and pneumonia, the most common presentation, doubles the risk of death. The alveolar macrophage is a sentinel pulmonary host defense cell, but the human alveolar macrophage in B. pseudomallei infection has never been studied. The objective of this study was to investigate the host-pathogen interaction of B. pseudomallei infection with the human alveolar macrophage and to determine the role of flagellin in modulating inflammasome-mediated pathways. We found that B. pseudomallei infects primary human alveolar macrophages but is gradually restricted in the setting of concurrent cell death. Electron microscopy revealed cytosolic bacteria undergoing division, indicating that B. pseudomallei likely escapes the alveolar macrophage phagosome and may replicate in the cytosol, where it triggers immune responses. In paired human blood monocytes, uptake and intracellular restriction of B. pseudomallei are similar to those observed in alveolar macrophages, but cell death is reduced. The alveolar macrophage cytokine response to B. pseudomallei is characterized by marked interleukin (IL)-18 secretion compared to monocytes. Both cytotoxicity and IL-18 secretion in alveolar macrophages are partially flagellin dependent. However, the proportion of IL-18 release that is driven by flagellin is greater in alveolar macrophages than in monocytes. These findings suggest differential flagellin-mediated inflammasome pathway activation in the human alveolar macrophage response to B. pseudomallei infection and expand our understanding of intracellular pathogen recognition by this unique innate immune lung cell.

Clinical presentation, complications, and outcomes of hospitalized COVID-19 patients in an academic center with a centralized palliative care consult service.

BACKGROUND AND AIMS: Palliative care is a critical component of the response of a healthcare system to a pandemic. We present risk factors associated with mortality and highlight an operational palliative care consult service in facilitating early identification of risk factors to guide goal-concordant care and rational utilization of finite healthcare resources during a pandemic. METHODS: In this case series of 100 consecutive patients hospitalized with COVID-19, we analyzed clinical data, treatment including palliative care, and outcomes in patients with SARS-CoV-2 infection admitted to three hospitals in Seattle, Washington. We compared data between patients who were discharged and non-survivors. RESULTS: Age (OR 4.67 [1.43, 15.32] ages 65-79; OR 3.96 [1.05, 14.89] ages 80-97), dementia (OR 5.62 [1.60, 19.74]), and transfer from a congregate living facility (OR 5.40 [2.07, 14.07]), as well hypoxemia and tachypnea (OR 7.00 [2.91, 22.41]; OR 2.78 [1.11, 6.97]) were associated with mortality. Forty-one (41%) patients required intensive care and 22 (22%) invasive mechanical ventilation. Forty-six (46%) patients were seen by the palliative care service, resulting in a change of resuscitation status in 54% of admitted patients. Fifty-eight (58%) patients recovered and were discharged, 34 (34%) died, and eight (8%) remained hospitalized, of which seven ultimately survived and one died. CONCLUSIONS: Older age, dementia, and congregate living were associated with mortality. Early discussions of goals of care facilitated by an operational palliative care consult service can effectively guide goal-concordant care in patients at high risk for mortality during a pandemic. Development of a functional palliative care consult service is an important component of pandemic planning.

Entrapped Coronary Arteries in Constrictive Pericarditis.

Pericardial constriction can be present without pericardial calcium and often without pericardial thickening. This epicardial coronary artery motion abnormality due to entrapment in a thickened, fibrotic pericardium, is characteristic of constrictive pericarditis, and differentiates this entity from other close differential diagnoses, such as restrictive and dilated cardiomyopathy.

Inhibition of Streptococcus mutans biofilms with bacterial-derived outer membrane vesicles.

BACKGROUND: Biofilms are microbial communities surrounded by a self-produced extracellular matrix which protects them from environmental stress. Bacteria within biofilms are 10- to 1000-fold more resistant to antibiotics, making it challenging but imperative to develop new therapeutics that can disperse biofilms and eradicate infection. Gram-negative bacteria produce outer membrane vesicles (OMV) that play critical roles in communication, genetic exchange, cargo delivery, and pathogenesis. We have previously shown that OMVs derived from Burkholderia thailandensis inhibit the growth of drug-sensitive and drug-resistant bacteria and fungi. RESULTS: Here, we examine the antibiofilm activity of Burkholderia thailandensis OMVs against the oral biofilm-forming pathogen Streptococcus mutans. We demonstrate that OMV treatment reduces biofilm biomass, biofilm integrity, and bacterial cell viability. Both heat-labile and heat-stable components, including 4-hydroxy-3-methyl-2-(2-non-enyl)-quinoline and long-chain rhamnolipid, contribute to the antibiofilm activity of OMVs. When OMVs are co-administered with gentamicin, the efficacy of the antibiotic against S. mutans biofilms is enhanced. CONCLUSION: These studies indicate that bacterial-derived OMVs are highly effective biological nanoparticles that can inhibit and potentially eradicate biofilms.

Burkholderia pseudomallei OMVs derived from infection mimicking conditions elicit similar protection to a live-attenuated vaccine.

Burkholderia pseudomallei is a Gram-negative, facultative intracellular bacillus that causes the disease melioidosis. B. pseudomallei expresses a number of proteins that contribute to its intracellular survival in the mammalian host. We previously demonstrated that immunization with OMVs derived from B. pseudomallei grown in nutrient-rich media protects mice against lethal disease. Here, we evaluated if OMVs derived from B. pseudomallei grown under macrophage-mimicking growth conditions could be enriched with intracellular-stage proteins in order to improve the vaccine. We show that OMVs produced in this manner (M9 OMVs) contain proteins associated with intracellular survival yet are non-toxic to living cells. Immunization of mice provides significant protection against pulmonary infection similar to that achieved with a live attenuated vaccine and is associated with increased IgG, CD4+, and CD8+ T cells. OMVs possess inherent adjuvanticity and drive DC activation and maturation. These results indicate that M9 OMVs constitute a new promising vaccine against melioidosis.

Community Pharmacy Operations in Puerto Rico During the 2017 Hurricane Season: A Descriptive Analysis of Rx Open Data.

OBJECTIVES: This article aims to: (1) describe the 'Return to Open Pharmacy Operations' in Puerto Rico following the hurricanes Irma and Maria in the 2017 hurricane season, and (2) compare the recovery rate (Return to Open Pharmacy Operations) during the 2017 hurricane season between the US Commonwealth of Puerto Rico and the state of Florida. METHODS: We performed a cross-sectional study of pharmacy operations in Puerto Rico utilizing Rx Open data for pharmacies in Puerto Rico during the 2017 hurricane season. To compare open rates of pharmacy operations over time in different contexts, we also analyzed Rx Open data for the state of Florida for Hurricane Irma. RESULTS: Only 11.1% of pharmacies remained open in Puerto Rico 3 days after Hurricane Maria made landfall, and Puerto Rico pharmacy operations recovered slowly, at an average daily rate of 3.9% before reaching pre-landfall baseline operations. Puerto Rico pharmacy operations after Hurricane Maria recovered 10 times slower on average, compared to pharmacy operations in Florida after Hurricane Irma which reached baseline operations less than 1 week following Hurricane Irma's landfall. CONCLUSION: Our results demonstrate the unique severity of Hurricane Maria's impacts on Puerto Rico's health system.

Immunological considerations in the development of Pseudomonas aeruginosa vaccines.

Pseudomonas aeruginosa is an opportunistic human pathogen capable of causing a wide range of potentially life-threatening infections. With multidrug-resistant P. aeruginosa infections on the rise, the need for a rationally-designed vaccine against this pathogen is critical. A number of vaccine platforms have shown promising results in pre-clinical studies, but no vaccine has successfully advanced to licensure. Growing evidence suggests that an effective P. aeruginosa vaccine may require Th17-type CD4+ T cells to prevent infection. In this review, we summarize recent pre-clinical studies of P. aeruginosa vaccines, specifically focusing on those that induce Th17-type cellular immunity. We also highlight the importance of adjuvant selection and immunization route in vaccine design in order to target vaccine-induced immunity to infected tissues. Advances in cellular immunology and adjuvant biology may ultimately influence better P. aeruginosa vaccine platforms that can protect targeted human populations.

Intradermal vaccination with a Pseudomonas aeruginosa vaccine adjuvanted with a mutant bacterial ADP-ribosylating enterotoxin protects against acute pneumonia.

Respiratory infections are a leading cause of morbidity and mortality globally. This is partially due to a lack of effective vaccines and a clear understanding of how vaccination route and formulation influence protective immunity in mucosal tissues such as the lung. Pseudomonas aeruginosa is an opportunistic pathogen capable of causing acute pulmonary infections and is a leading cause of hospital-acquired and ventilator-associated pneumonia. With multidrug-resistant P. aeruginosa infections on the rise, the need for a vaccine against this pathogen is critical. Growing evidence suggests that a successful P. aeruginosa vaccine may require mucosal antibody and Th1- and Th17-type CD4+ T cells to prevent pulmonary infection. Intradermal immunization with adjuvants, such as the bacterial ADP-Ribosylating Enterotoxin Adjuvant (BARE) double mutant of E. coli heat-labile toxin (dmLT), can direct protective immune responses to mucosal tissues, including the lungs. We reasoned that intradermal immunization with P. aeruginosa outer membrane proteins (OMPs) adjuvanted with dmLT could drive neutralizing antibodies and migration of CD4+ T cells to the lungs and protect against P. aeruginosa pneumonia in a murine model. Here we show that mice immunized with OMPs and dmLT had significantly more antigen-specific IgG and Th1- and Th17-type CD4+ memory T cells in the pulmonary environment compared to control groups of mice. Furthermore, OMPs and dmLT immunized mice were significantly protected against an otherwise lethal lung infection. Protection was associated with early IFN-γ and IL-17 production in the lungs of immunized mice. These results indicate that intradermal immunization with dmLT can drive protective immunity to the lung mucosa and may be a viable vaccination strategy for a multitude of respiratory pathogens.

Prolonged Activated Clotting Time Immediately Prior to Open Cardiac Surgery.

BACKGROUND: Prekallikrein deficiency is an extremely rare disorder in which functional prekallikrein in the plasma is reduced or absent. CASE REPORT: We present the case of a 15-year-old male with prolonged activated clotting time incidentally noted preoperatively prior to repair of an atrial septal defect. The patient was subsequently found to have prekallikrein (Fletcher factor) deficiency. He successfully underwent open cardiac surgical repair after fresh frozen plasma was administered at a dose of 15 mL/kg 1 hour prior to the start of the procedure. CONCLUSION: History and routine preoperative evaluations of complete blood count, partial thromboplastin time, prothrombin time, and platelet function analysis failed to detect any abnormalities, but a prolongation of activated clotting time identified by the anesthesiologist led to specialized testing and a diagnosis of Fletcher factor deficiency. The patient tolerated the open-heart surgery well without any significant hematologic intervention or complications.

Post-Operative Infections: Trends in Distribution, Risk Factors, and Clinical and Economic Burdens.

BACKGROUND: Post-operative infection (POI) is a serious complication in all surgical disciplines and can derail a patient's treatment and recovery course. In this analysis, we examine national trends, risk factors, and costs associated with POI. METHODS: Using the Nationwide Inpatient Sample (NIS) for the years available for data analysis at the time of this study (2003-2010), we performed a cross-sectional study of adult (≥18 years) inpatients with POI and designated Clinical Classification Software (CCS) procedural class codes for the operations performed. A comparison group was selected randomly from patients with the same CCS codes who underwent the same procedures but did not experience POI. As the NIS represents 20% of U.S. hospital admissions, excess cost and stay were calculated on the basis of the average difference between cost and duration of stay for POI cases and the cost and duration of stay for the comparison group, then extrapolated to estimate the national burden for the remaining 80% of stays nationwide. RESULTS: Sample admissions included 139,652 cases of POI and 941,670 comparison subjects. The POIs were most common in procedures involving the digestive tract (46.5%), cardiovascular system (16.3%), or musculoskeletal system (11.2%). Older age, male gender, high Charlson Comorbidity Index Score (CCIS), and teaching, urban, or large hospitals were independent risk factors for POI in the multivariable model (p < 0.05). A POI was associated with a higher risk of death (odds ratio 2.93; 95% confidence interval 2.82-3.04, p < 0.001). Nationally, we estimate that POI resulted in an annual average of 1.04 million days of excess hospital stay and $2.72 billion excess cost. CONCLUSIONS: Identification of independent risk factors suggests areas for quality improvement initiatives. Post-operative infection carries substantial clinical and financial burdens in the United States, and further analysis of the associated costs is needed to identify areas for intervention to reduce this burden.

A Burkholderia pseudomallei Outer Membrane Vesicle Vaccine Provides Cross Protection against Inhalational Glanders in Mice and Non-Human Primates.

Burkholderia mallei is a Gram-negative, non-motile, facultative intracellular bacillus and the causative agent of glanders, a highly contagious zoonotic disease. B. mallei is naturally resistant to multiple antibiotics and there is concern for its potential use as a bioweapon, making the development of a vaccine against B. mallei of critical importance. We have previously demonstrated that immunization with multivalent outer membrane vesicles (OMV) derived from B. pseudomallei provide significant protection against pneumonic melioidosis. Given that many virulence determinants are highly conserved between the two species, we sought to determine if the B. pseudomallei OMV vaccine could cross-protect against B. mallei. We immunized C57Bl/6 mice and rhesus macaques with B. pseudomallei OMVs and subsequently challenged animals with aerosolized B. mallei. Immunization with B. pseudomallei OMVs significantly protected mice against B. mallei and the protection observed was comparable to that achieved with a live attenuated vaccine. OMV immunization induced the production of B.mallei-specific serum IgG and a mixed Th1/Th17 CD4 and CD8 T cell response in mice. Additionally, immunization of rhesus macaques with B. pseudomallei OMVs provided protection against glanders and induced B.mallei-specific serum IgG in non-human primates. These results demonstrate the ability of the multivalent OMV vaccine platform to elicit cross-protection against closely-related intracellular pathogens and to induce robust humoral and cellular immune responses against shared protective antigens.

Evaluating the efficacy of a centrifugation-flotation method for extracting Ascaris ova from soil.

BACKGROUND: Soil transmitted helminths (STH) continue to be associated with high burdens of disease, with an estimated 1.45 billion people infected with STH globally. The promotion and construction of latrines is considered the first barrier to prevent transmission of STH. The absence of a reliable method to extract STH ova from soil makes it challenging to examine whether the use of latrines may or may not have an effect on environmental contamination with ova. The present study evaluated the recovery rate of a method developed to extract STH ova from soil. METHODS: The adapted centrifugation and flotation technique was applied to 15 soil types, which were seeded with Ascaris suum ova. Soil type, soil moisture content, soil texture and organic matter content were assessed for each soil sample. RESULTS: The average ova recovery rate was 28.2%, with the recovery rate of the method decreasing with increasing soil moisture content, particle size and organic matter content. The association between recovery rate and organic matter content was statistically significant. CONCLUSIONS: The present study identified a low recovery rate for an adapted centrifugation-flotation method, although this was similar to the recovery rate demonstrated by other methods developed for soil. Soil organic matter content was significantly associated with ova recovery rates.

Serum hyperchloremia as a risk factor for acute kidney injury in patients with ST-segment elevation myocardial infarction undergoing percutaneous coronary intervention.

A high serum chloride concentration has been associated with the development of acute kidney injury in critically ill patients. However, the association between hyperchloremia and acute kidney injury (AKI) in patients admitted with ST-segment elevation myocardial infarction (STEMI) treated with percutaneous coronary intervention (PCI) is unknown. A retrospective analysis of consecutive patients admitted with the diagnosis of STEMI and treated with PCI was performed. Subjects were classified as having hyper- or normochloremia based upon their admission serum chloride level. Multivariable logistic regression analyses were employed for the primary and secondary outcomes. The primary analysis evaluated whether high serum chloride on admission was associated with the development of AKI after adjusting for age, diabetes mellitus, admission systolic blood pressure, contrast volume used during angiography, Killip class, and need for vasopressor therapy or intraaortic balloon pump. The secondary analyses evaluated whether high serum chloride was associated with sustained ventricular tachycardia or fibrillation. Of 291 patients (26.1% female, mean age of 59.9 ± 12.6 years, and mean body mass index of 29.3 ± 6.1 kg/m(2)), 25 (8.6%) developed AKI. High serum chloride on admission did not contribute significantly to the development of AKI (odds ratio, 95%; confidence interval, 0.90 to 1.24). In addition, serum chloride on admission was not significantly associated with sustained ventricular tachycardia or fibrillation after adjusting for demographic and clinical covariates. In conclusion, our study demonstrated no association between baseline serum hyperchloremia and an increased risk of AKI in patients admitted with STEMI treated with PCI.

Helminth transmission in simple pit latrines.

Simple pit latrines often represent the cheapest form of sanitation for poor communities. However, simple latrines lack a concrete slab and are therefore classified as an unimproved form of sanitation. This study collected soil samples in simple pit latrines and analysed them for the presence of helminth eggs; 71% of all collected samples were positive for eggs. The absence of a roof from the latrine was the only factor associated with lower egg concentrations. The findings support the classification of simple pit latrines as an unimproved form of sanitation.