Extrapulmonary Infection Research Articles

Clinical and Imaging Characteristics of Primary Severe Community-Acquired Pneumonia Caused by Hypervirulent Klebsiella Pneumoniae.

To investigate the CT imaging features and microbial phenotypes of primary severe community-acquired pneumonia caused by hypervirulent Klebsiella pneumoniae (hvKp). Patients diagnosed with primary hvKp pneumonia were included, and their clinical data were analyzed, including the baseline characteristics and CT imaging results. After hypermucoviscosity phenotyping, the strains, serological types, and virulence genes of hvKp were identified using multiplex PCR. Twelve patients with primary hvKp pneumonia were included (11 males, 1 female). All patients were infected via respiratory tract inhalation. Ten patients were long-term drinkers. Four patients (33.3%), who were long-term alcohol abusers, died within 30 days after diagnosis. No extrapulmonary metastatic infection was found in any patient. The imaging of lung lesions at the early disease stage exhibited an extensive consolidation in the lungs. As the disease progressed, the most common imaging features were pleural effusion (9/12), cavitation and necrosis (8/12), and pneumothorax (3/12). The serological typing of the capsular polysaccharides on hvKp strains were K1 (6/12) and K2 (6/12). Furthermore, the virulence genotyping showed rmpA (11/12), magA (11/12), ureA (12/12), mrkD (12/12), fim-1 (12/12), wabG (12/12), ybtS (12/12), and iucB (11/12). Primary severe community-acquired hvKp-associated pneumonia is more common in men, especially those with a long-term history of alcohol consumption. CT scanning at the early disease stage mostly showed extensive pulmonary consolidation, which was prone to be combined with cavitation, necrosis, and pleural effusion. K1 and K2 serotypes were identified among the hvKp strains, which were not prone to form extrapulmonary metastasis via the bloodstream.

Coinfection of pulmonary tuberculosis with other lower respiratory tract infections: A retrospective cross-sectional study.

Little attention has been given to the development of lower respiratory tract infections (LRTIs) in patients with pulmonary tuberculosis (PTB) during their anti-tuberculosis (anti-TB) treatment and how that might affect patients' health status. Here, the prevalence and etiologies of other LRTIs in a cohort of PTB patients were determined, and the clinical features and outcomes were described. Adult patients with PTB between 2015 and 2020 were recruited and monitored during their anti-TB treatment for the presence of LRTIs. Clinical data were retrospectively collected from patients' medical records. Data from 76 PTB patients (57 [75%] males) were reviewed. The median age was 61.0 (interquartile range 83.5-35.5) years, and other LRTIs were detected in 45 (59.2%) PTB patients. Of the 126 episodes of LRTIs, 84 (66.7%) were due to bacterial infections, 37 (29.4%) were due to fungal infections, and 5 (3.9%) were due to viral infections. The development of LRTIs was significantly more common in older (P = 0.012) and hypertensive patients with PTB (P = 0.019). Patients with PTB and LRTIs experienced significantly more frequent extrapulmonary infections (P = 0.0004), bloodstream infections (P = 0.001), intensive care unit stays (P = 0.001), and invasive mechanical ventilation use (P = 0.03) than patients who did not develop LRTI. The identification of host-related risk factors for LRTI development among patients with PTB could be used to develop a prediction model for LRTI development. Hence, initiating antimicrobials early, in parallel with appropriate anti-TB treatment, may mitigate PTB-related health and economic consequences.

703. Peritoneal Coccidioidomycosis in a Pediatric Patient: An Extremely Rare Presentation and Literature Review

BackgroundChronic peritonitis is an unusual manifestation of coccidiomycosis (CM) that is challenging to diagnose and manage due to its propensity for relapse. It is even more unusual to diagnose peritoneal CM in the pediatric population, with only two other cases reported in the literature. MethodsWe present the case of a previously healthy 5-year-old Filipino female in Florida who was diagnosed with peritoneal CM. After months of unintentional weight loss and worsening abdominal distention, she presented to medical care. Imaging revealed significant abdominal ascites and nodularities throughout the peritoneum. The peritoneal fluid demonstrated a lymphocytic pleocytosis and infectious workup was benign. CA125 levels were elevated, but peritoneal adenosine deaminase was within normal limits. A biopsy of the affected tissue revealed diffuse granulomas surrounding spherules that were positive on GMS and PAS staining, concerning for CM. Exposure history revealed that she was raised in California and moved to Florida one year prior to presentation. Complement fixation titers were significantly elevated at ≥ 1:512 and immunodiffusion titers were positive. A Coccidioides PCR was sent from the tissue to the Mayo clinic and was positive, and fungal cultures from the tissue grew C. immitis/posadasii. Immunologic workup was reassuring. She was started on oral Fluconazole with rapid resolution of her symptoms. ResultsInvolvement of the peritoneum in CM is extremely rare. Abdominal distention due to ascites is the most common presentation, and the peritoneal fluid is typically exudative. Imaging may reveal peritoneal deposits which can mimic other infections and malignancy. Diagnosis can be based on histopathological demonstration of fungal structures, cultures, antibody testing, antigen detection and/or PCR. Treatment guidelines suggest azole therapy for nonmeningeal disseminated CM with at least 6–12 months of treatment for extrapulmonary coccidioidal soft tissue infection. ConclusionPeritoneal CM is an extremely uncommon condition and it is even more rare in the pediatric population, but should be considered in those in the appropriate clinical settings, particularly if they have history to suggest exposure to regions where this fungus is endemic. Disclosures All Authors: No reported disclosures

Retropharyngeal Abscess and Pott’s Disease Due to Tuberculosis: A Case Report

Introduction: Extrapulmonary mycobacterial infection can lead to vertebral spondylitis and osteomyelitis (Pott’s disease). Retropharyngeal abscess with concurrent spinal osteomyelitis is a rare presentation of tuberculosis in the US. Chart review on a patient was completed, and the relevant published literature was reviewed. Case Presentation: A previously healthy 34-year-old male originally from Sudan presented to an outside hospital with a 2-month history of neck pain, sore throat, odynophagia, fevers, and chills. MRI showed a retropharyngeal abscess and suspected cervical spine osteomyelitis. Acid-fast bacillus (AFB) smear was positive from a neck drain specimen, but sputum was negative. Chest imaging did not show findings consistent with pulmonary tuberculosis. He was treated with rifampin, isoniazid, pyrazinamide, and ethambutol (RIPE) along with moxifloxacin and linezolid due to concern for possible multidrug resistant tuberculosis and transferred to our center for further care. Culture isolated Mycobacterium tuberculosis. CT neck showed vertebral tuberculous osteomyelitis (Pott’s disease) of C1-C3 with a multiloculated retropharyngeal and prevertebral abscess (Figure 1). The patient was taken to the OR for posterior spinal fusion from occiput to C4 and transoral incision and drainage of the abscess. The post-operative course was uneventful, and moxifloxacin and linezolid were discontinued when Xpert MTB/RIF test revealed rifampin susceptibility. At follow-up the patient’s symptoms had resolved. Patient consent was obtained to utilize this case for educational purposes. Conclusions: This report presents the multidisciplinary treatment of this patient requiring infection control measures and antibiotic therapy by infectious disease, posterior spine fusion by orthopedic surgery, and retropharyngeal abscess drainage by otolaryngology.

Comparative diagnostic value of GeneXpert MTB/RIF, PCR targeting IS6110 and culture for the diagnosis of spinal tuberculosis

Introduction Spinal tuberculosis is an extra-pulmonary tuberculosis infection caused by Mycobacterium tuberculosis (MTB) which affects the vertebrae. Culture test is the «gold standard» diagnostic method, but it takes a long time. PCR is a method of a shorter time than the culture test, so it can be an alternative diagnostic method for MTB. Materials and Methods This study is a cross-sectional study. The data were analyzed with diagnostic tests on patients with suspected spinal tuberculosis who performed surgery in Hasan Sadikin Hospital in Bandung. Clinical examinations and diagnostic examinations were done in 40 patients and surgery was performed to obtain samples from the spinal cord and the infected tissue. GeneXpert, PCR targeting IS6110 and culture tests were performed. The research was conducted at the Department of Orthopaedics and Traumatology and the Clinical Pathology Laboratory of FK UNPAD/RSHS from September 2019 to September 2020. Results GeneXpert assay compared with culture tests as the standard diagnostic method showed sensitivity of 96.67 %; specificity of 90.00 %; positive predictive value 96.67 %; and a negative predictive value of 90.00 %, with an accuracy of 95.00 %. The PCR targeting IS6110 against culture showed that the sensitivity of MTB bacterial infection was 93.33 %, the specificity was 80.00 %, the positive predictive value was 93.33 %, the negative predictive value was 80.00 %, and the accuracy was 90.00 %. Conclusion This study concluded that the GeneXpert MTB/RIF RT-PCR assay has a high sensitivity, specificity, and accuracy compared to PCR targeting IS6110 in examining tissue samples in patients with spinal TB.

The epidemiology, demographics, and comorbidities of pulmonary and extra-pulmonary non-tuberculous mycobacterial infections at a large central Florida Academic Hospital

RationaleIn the United States, non-tuberculous mycobacterium (NTM) infections are considered an important cause of morbidity and mortality, especially in people with progressive lung disease. The state of Florida has an extremely high incidence and prevalence of NTM disease which is likely a rapidly emerging infection in the state due to environmental and demographic factors. ObjectivesAdjemian et al. [1] To determine the burden of NTM disease of patients admitted to a large Central Florida academic center, Falkinham [2] to identify the most common risk factors associated with developing NTM disease in this area, and Sfeir et al. [4] to categorize antimicrobial susceptibilities and genetic resistance markers. MethodsWe conducted a retrospective case review from January 1, 2011 to December 31, 2017 in a large university-associated metropolitan hospital in west-central Florida. NTM infections were identified using TheraDoc® during the study period with the inclusion criteria of any inpatient admission, culture confirmed NTM at any site, and age ≥ 12 years. Demographic variables (including residential zip code) and comorbidity data (including solid organ transplant status, HIV status and subsequent testing results, intrinsic pulmonary disease, and cancer diagnosis of any site) were collected for each patient. Microbiologic data collected included NTM species/subspecies, anatomic location of specimen collection, antimicrobial susceptibility including minimum inhibitory concentration (MIC). All collected data were analyzed within Stata/IC14.2. Geospatial relationships between zip codes, diagnosis type, and co-morbidities were computed using Arc GIS Pro. ResultsOur results demonstrated that a substantial number of our inpatient cases with NTM were of the M. abscessus group, and with M. avium complex and M. fortuitum also representing the pathogen in numerous cases. Novel findings included compilation of the first hospital wide comprehensive NTM resistance plot to our knowledge. Our results did show a concordance with previous data with expected predominance of NTM inpatient cases in Caucasian males with pre-existing pulmonary disease, though additional work could be done with isolates within the transplant and immunosuppressed populations. ConclusionsOur data set demonstrates the most common species/subspecies of NTM infections and their associated conditions seen at our central Florida hospital, and includes an antimicrobial sensitivity analysis in toto. This could be insight into the possible prevalence of NTM in the area, and provides the foundation for future studies on both the acquisition and prevention for NTM infections in central Florida.

Cutis Tuberculosis

Background: Tuberculosis (TB) is spreading globally, and more than two billion people (about 30% of the world's population) are thought to be infected with M. tuberculosis. Tuberculosis cutis is an extrapulmonary Mycoterium tuberculosis infection that attacks the skin. Research Methods: The writing of this article includes various sources originating from scientific journals and government guidelines and related agencies. Source searches were conducted on the online portals of journal publications such as MedScape, Google Scholar and NCBI (ncbi.nlm.nih.gov). Results: Cutaneous TB can be transmitted through exposure to the lungs or infected aerosols entering the lungs. Cutaneous TB is divided into True Cutaneous TB which consists of primary and secondary TB, and Tuberculid Overall, the treatment of cutaneous TB is similar to that of systemic TB, which tends towards multi-drug therapy. Several anti-tuberculosis drugs such as isoniazid, rifampin, and pyrazinamide have been recommended as drugs for the treatment of cutaneous tuberculosis. It was reported that in a five-year follow-up approximately 12.5% ??of cutaneous TB patients showed relapse after standard anti-TB therapy. Conclusion: To reduce the mortality rate, the public needs to be given education regarding the dangers and ways to prevent TB disease to increase public awareness. More long-term studies are needed to understand the recurrence rate of various cutaneous tuberculosis under current treatment recommendations, especially in immunocompromised patients.

Genomic analysis of Burkholderia cenocepacia isolated from a liver abscess in a patient with cystic fibrosis.

Burkholderia cenocepacia complex is associated with high transmissibility, virulence, and poor prognosis in cystic fibrosis (CF) patients. However, extrapulmonary infections are rare. We investigated the genome of a B.cenocepacia IIIA isolated from a liver abscess in a Brazilian CF patient and compared it to strain J2315. The whole genome was sequenced, and contigs were annotated by Rapid Annotation using Subsystem Technology. The Pathosystems Resource Integration Center was used to map antimicrobial and virulence genes. The genomic island (GIs) analysis was performed using two prediction methods, and the presence of putative plasmids and insertion sequences (ISs) was investigated. The isolate was confirmed as B.cenocepacia IIIA to ST-28 (ET12 lineage). A total of 64 genes for antimicrobial resistance and 47 genes related to virulence were identified. Among the virulence factors, there was a predominance of factors related to the invasion mechanism, to the flagellar biosynthesis protein, and to the RNA polymerase sigma factor for flagellar operon (cdpA). Two IS families (IS3 and IS5) and only one plasmid were found. On average 56 GIs were predicted by at least one of the methods applied. Comparative analysis showed resistance mechanisms and virulence factors revealing invasive determinants used by B. cenocepacia IIIA (ET12) in the process of disease spread to other infection sites (extrapulmonary) of highly virulent strains in CF patients.

Diagnosis of Peritoneal Tuberculosis from Primary Peritoneal Cancer.

Peritoneal tuberculosis (PTB) is an uncommon extrapulmonary infection mimickng primary peritoneal cancer (PPC). We retrospectively included 23 women with PTB and 47 women with PPC treated in a medical center to study the clinical and radiological features that differentiate PTB from PPC. Body temperature above 38 °C was a unique feature of PTB (34.7% versus 0%, p < 0.001). Body Mass Index (BMI) was lower (21.9 ± 3.7 versus 25.2 ± 4.1, p = 0.003), white blood cell (WBC) count was lower (5179.6 ± 1502.2 versus 7716.2 ± 2741.8, p < 0.001), and CA-125 level was lower (508.0 ± 266.1 versus 2130.1 ± 2367.2 U/mL, p < 0.001) in PTB compared with PPC. Imaging detected more pulmonary infiltration and consolidation (52.2% versus 6.4%, p < 0.001), and less omental/mesentery changes (52% versus 83%, p < 0.001) in PTB compared with PPC. The operated patients received earlier treatment compared to patients without operation (7.9 ± 5.3 days versus 17.2 ± 11.0 days, p = 0.010). In conclusion, fever above 38 °C, lower BMI, lower WBC count, less elevated CA-125 level, and imaging of less omental involvement were features of PTB differentiated from PPC.

LEGIONNAIRES' DISEASE: A FATAL FORM OF COMMUNITY-ACQUIRED PNEUMONIA

TOPIC: Chest Infections TYPE: Fellow Case Reports INTRODUCTION: Legionella pneumophila is gram-negative bacilli known to cause community-acquired pneumonia (CAP), also termed Legionnaires' disease. While pneumonia is the most common manifestation, extrapulmonary infections include renal injury and rhabdomyolysis. Age, immunosuppression and multi-system infection increase mortality, even with early initiation of therapy. CASE PRESENTATION: A 30-year-old male with history of bipolar disease, alcohol and tobacco abuse presented with diarrhea, fever and confusion for three days. He was found to be febrile, tachycardic, encephalopathic and hypoxic requiring high-flow nasal cannula. Initial evaluation revealed leukocytosis, acute liver injury, acute renal injury, respiratory alkalosis, lactic acidosis, and elevated troponin and creatine kinase levels. Chest x-ray (CXR) showed a dense left upper lobe consolidation. Sepsis was worked up and he was given intravenous fluids and antibiotics (Vancomycin, Cefepime, Metronidazole, Azithromycin). Over several hours, he became oliguric, tachypnic and hypotensive requiring vasopressors, continuous renal replacement therapy (CRRT) and mechanical ventilation. Urinary legionella antigen returned positive so Levofloxacin was added. Despite antibiotics and CRRT, his shock worsened and he ultimately had pulseless electrical activity arrest with demise. DISCUSSION: The presence of acute renal injury in Legionnaires' disease increases mortality up to 51% so early diagnosis is crucial to guide management. The urinary antigen test for L. pneumophila only identifies serogroup 1, which is the most common type. When prevalence is high, specificity of this test is >99%. Severe cases of CAP should be tested for Legionella as half of patients with Legionnaires' disease will require intensive care. Rhabdomyolysis occurs due to direct toxin invasion and renal injury occurs subsequently or due to sepsis. Levofloxacin or Azithromycin are the antibiotics of choice as they are bactericidal and reach high intracellular concentrations. There are twenty-two known cases of Legionnaires' disease with rhabdomyolysis and acute renal injury. Nearly all patients with this triad survived and of those who did, all received antibiotics and about half required hemodialysis (HD). To our knowledge, there is only one other case where the outcome was death despite several days of HD. In comparison, presentation to death occurred in less than twenty-four hours in our case. Cause of death was refractory hyperkalemia due to rhabdomyolysis-induced renal injury despite CRRT. CONCLUSIONS: Even with timely diagnosis and treatment of Legionnaires' disease, renal involvement portends a high mortality rate. At the earliest evidence of renal injury in Legionnaires' disease complicated by rhabdomyolysis, immediate placement of central venous catheters and early initiation of CRRT is mandatory and may be life saving. REFERENCE #1: Soni AJ, Peter A. Established association of legionella with rhabdomyolysis and renal failure: A review of the literature. Respir Med Case Rep. 2019 Oct 28;28:100962. REFERENCE #2: Mercante, J. W., & Winchell, J. M. (2015). Current and emerging Legionella diagnostics for laboratory and outbreak investigations. Clinical microbiology reviews, 28(1), 95–133. REFERENCE #3: Straus W.L., Plouffe J.F., File T.M. Risk factors for domestic acquisition of Legionnaires' disease. Ohio Legionnaires Disease group. Arch. Intern. Med. 1996;156(15):1685–1692. DISCLOSURES: No relevant relationships by Allen Roberts, source=Web Response No relevant relationships by Jigna Solanki, source=Web Response

FATAL COVID-19 COMPLICATION IN A LATIN-AMERICAN HEALTHY FEMALE

TOPIC: Chest Infections TYPE: Medical Student/Resident Case Reports INTRODUCTION: Covid-19 is not just a respiratory virus, it can show up atypically and does not discriminate age, gender or health status. Many people have had the disease with just mild symptoms. However, symptoms can vary from as simple as flu-like illness to severe systemic disease leading to dead. CASE PRESENTATION: This is a case of a 41-year-old Latin-American female who came to the Emergency Department (ED) complaining of general malaise after arriving from Dominican Republic. Symptoms started 1.5 week, associated with myalgias, subjective fever, fatigue, dyspnea non-proportional to exertion and SOB, which progressed to chest discomfort relieved by sitting up and worsened by lying down. Physical examination was remarkable for a toxic appearing patient, hemodynamically stable on mild distress due to generalized muscle aches. Lungs were clear to auscultation. Cardiac examination revealed tachycardia without murmurs, rubs, gallops or JVD. No edema or cyanosis noted. Abdominal exam revealed diffuse moderate tenderness without peritoneal sign. Labs revealed leukocytosis with left shift, mild transaminitis, lactic acidemia and elevated cardiac troponins. COVID-19 antigen test was positive. EKG revealed sinus tachycardia with premature atrial contractions. Bedside ultrasound revealed pericardial effusion with diastolic right ventricular collapse. Patient was immediately managed with aggressive intravenous isotonic fluid. Afterwards, patient developed tachypnea, neurological and hemodynamic deterioration. Patient was endotracheally intubated and sono-guided pericardiocentesis was performed. Post-procedure cardiac sonogram revealed resolution of pericardial effusion, however poor cardiac contractility and hypotension noted for which was placed on Norepinephrine and Dobutamine Drip with improvement of hemodynamics. Despite management patient underwent cardiac arrest and died. DISCUSSION: COVID-19 infection presents with a wide variety of symptoms, which leads to a diagnostic challenge since have demonstrated to be more than a respiratory virus. This case is an example of clinically suspected myocarditis by COVID-19 virus, which shown this virus have myotropic effects. Our patient presented with predominantly with signs and symptoms of right heart dysfunction secondary to pericardial effusion complicated by suspected fulminant clinical myocarditis w/o typical changes in lung imaging. Unfortunately, patient was not stable to undergo endomyocardial biopsy or cardiac MRI. However, patient fulfilled clinical criteria for diagnosis. CONCLUSIONS: This case is an example of COVID-19 extra-pulmonary infection, as well as the importance of increasing awareness on disease prevention and vaccination. REFERENCE #1: https://www.uptodate.com/contents/clinical-manifestations-and-diagnosis-of-myocarditis-in-adults/abstract/1 DISCLOSURES: No relevant relationships by Migdoel Cruz Rodriguez, source=Web Response No relevant relationships by Joel Gonzalez Chaple, source=Web Response No relevant relationships by Josue Ocasio Tapia, source=Web Response No relevant relationships by Neshma Roman-Velez, source=Web Response No relevant relationships by Juan Santiago, source=Web Response No relevant relationships by Michel Santiago-Berrios, source=Web Response No relevant relationships by Pedro Vargas, source=Web Response

Platelet-Based Biomarkers for Diagnosis and Prognosis in COVID-19 Patients.

Coronavirus disease 2019 (COVID-19) caused millions of deaths worldwide. COVID-19’s clinical manifestations range from no symptoms to a severe acute respiratory syndrome, which can result in multiple organ failure, sepsis, and death. Severe COVID-19 patients develop pulmonary and extrapulmonary infections, with a hypercoagulable state. Several inflammatory or coagulatory biomarkers are currently used with predictive values for COVID-19 severity and prognosis. In this manuscript, we investigate if a combination of coagulatory and inflammatory biomarkers could provide a better biomarker with predictive value for COVID-19 patients, being able to distinguish between patients that would develop a moderate or severe COVID-19 and predict the disease outcome. We investigated 306 patients with COVID-19, confirmed by severe acute respiratory syndrome coronavirus 2 RNA detected in the nasopharyngeal swab, and retrospectively analyzed the laboratory data from the first day of hospitalization. In our cohort, biomarkers such as neutrophil count and neutrophil-to-lymphocyte ratio from the day of hospitalization could predict if the patient would need to be transferred to the intensive care unit but failed to identify the patients´ outcomes. The ratio between platelets and inflammatory markers such as creatinine, C-reactive protein, and urea levels is associated with patient outcomes. Finally, the platelet/neutrophil-to-lymphocyte ratio on the first day of hospitalization can be used with predictive value as a novel severity and lethality biomarker in COVID-19. These new biomarkers with predictive value could be used routinely to stratify the risk in COVID-19 patients since the first day of hospitalization.

Rapid Detection and Quantification of Mycobacterium tuberculosis DNA in Paraffinized Samples by Droplet Digital PCR: A Preliminary Study.

Background: Rapid and reliable diagnosis of tuberculosis (TB) represents a diagnostic challenge in compartmentalized extrapulmonary TB infection because of the small number of mycobacteria (MTB) and the frequent lack of fresh samples to perform culture. Here, we estimate the performances of homemade droplet digital PCR (ddPCR)-based assays against culture in 89 biopsies, for those fresh and formalin-fixed and paraffin-embedded (FFPE) subsamples were available.Methods: MTB diagnosis in fresh subsamples was performed by culture. Fresh subsamples were also analyzed for acid-fast bacilli smear-microscopy (AFB) and Xpert® MTB/RIF (Xpert). MTB examination was repeated in blind in the 89 FFPE subsamples by in-house ddPCR assays targeting the IS6110 and rpoB. Analytical sensitivity of ddPCR assays was evaluated using serial dilution of H37Rv strain. Limit of detection (LOD) was calculated by probit analysis. Results were expressed in copies/106 cells.Results: IS6110 and rpoB ddPCR assays showed a good linear correlation between expected and observed values (R2: 0.9907 and 0.9743, respectively). Probit analyses predicted a LOD of 17 and 40 copies/106 cells of MTB DNA for IS6110 and rpoB, respectively. Of the 89 biopsies, 68 were culture positive and 21 were culture negative. Considering mycobacterial culture as reference method, IS6110 assay yielded positive results in 67/68 culture-positive samples with a median interquartile range (IQR) of 1,680 (550–8,444) copies/106 cells (sensitivity: 98.5%; accuracy: 98.9). These performances were superior to those reported by the rpoB assay in FFPE subsamples (sensitivity: 66.20%; accuracy: 74.1) and even superior to those reported by Xpert and AFB in fresh subsamples (sensitivity: 79.4 and 33.8%, respectively; accuracy: 84.3 and 49.4, respectively). When Xpert and AFB results were stratified according to mycobacterial load detected by rpoB and IS6110 ddPCR, bacterial load was lower in Xpert and AFB negative with respect to Xpert and AFB-positive samples (p = 0.003 and 0.01 for rpoB and p = 0.01 and 0.11 for IS6110), confirming the poor sensitivity of these methods in paucibacillary disease.Conclusion: ddPCR provides highly sensitive, accurate, and rapid MTB diagnosis in FFPE samples, as defined by the high concordance between IS6110 assay and culture results. This approach can be safely introduced in clinical routine to accelerate MTB diagnosis mainly when culture results remain unavailable.

Diagnostic Value of Endotracheal Tube-Aspirate Soluble Triggering Receptor Expressed on Myeloid Cells-1 Concentration for Neonatal Ventilator-Associated Pneumonia.

Background: Soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) is regarded as a biological marker of infection. We aimed to evaluate the diagnostic value of endotracheal tube (ETT)-sTREM-1 concentration in neonatal ventilator-associated pneumonia (NVAP), to explore the difference of (ETT)-sTREM-1 between preterm and full-term, and to investigate the influence of extrapulmonary infection on (ETT)-sTREM-1 concentration.Methods: In this multicenter, controlled clinical trial of 60 preterm and 33 full-term neonates on mechanical ventilators, we measured concentrations of ETT-aspirate and serum sTREM-1, serum C-reactive protein, and serum procalcitonin, as well as white blood cell count. We initially divided cases into eight groups, based on three categories: preterm of full-term; NVAP or non-NVAP; and extrapulmonary infection present or absent. Groups were compared, and logistic regression analysis and receiver operating characteristic (ROC) analysis was performed to determine diagnostic value.Results: The mean gestational age (± standard deviation) of preterm and full-term neonates was 28.9 ± 2.2 weeks and 39.5 ± 1.7 weeks, respectively, and 32/60 were male. The ETT-aspirate sTREM-1 concentration was higher in NVAP cases than in non-NVAP cases, irrespective of extrapulmonary infection. ROC analysis revealed that ETT-aspirate sTREM-1 concentration had an area under the curve (AUC) of 0.986 and a cutoff value of 228.0 pg/ml (sensitivity, 94.3%; specificity, 96%) in preterm neonates; the same values in full-term neonates were 0.938 and 245.5 pg/ml (sensitivity, 100%; specificity, 93.7%), respectively. The optimal combination of indicators was ETT-aspirate sTREM-1 and serum C-reactive protein concentration. All indicators were present at lower levels on days 8 and 10 of ventilation in neonates who ultimately recovered than in those who did not.Conclusions: ETT-aspirate sTREM-1 and serum C-reactive protein concentrations may be useful for the diagnosis of NVAP.

Mycobacterium bovis Bacillus Calmette-Guérin-Infected Dendritic Cells Induce TNF-α-Dependent Cell Cluster Formation That Promotes Bacterial Dissemination through an In Vitro Model of the Blood-Brain Barrier.

CNS tuberculosis (CNSTB) is the most severe manifestation of extrapulmonary tuberculosis infection, but the mechanism of how mycobacteria cross the blood-brain barrier (BBB) is not well understood. In this study, we report a novel murine in vitro BBB model combining primary brain endothelial cells, Mycobacterium bovis bacillus Calmette-Guérin-infected dendritic cells (DCs), PBMCs, and bacterial Ag-specific CD4+ T cells. We show that mycobacterial infection limits DC mobility and also induces cellular cluster formation that has a similar composition to pulmonary mycobacterial granulomas. Within the clusters, infection from DCs disseminates to the recruited monocytes, promoting bacterial expansion. Mycobacterium-induced in vitro granulomas have been described previously, but this report shows that they can form on brain endothelial cell monolayers. Cellular cluster formation leads to cluster-associated damage of the endothelial cell monolayer defined by mitochondrial stress, disorganization of the tight junction proteins ZO-1 and claudin-5, upregulation of the adhesion molecules VCAM-1 and ICAM-1, and increased transmigration of bacteria-infected cells across the BBB. TNF-α inhibition reduces cluster formation on brain endothelial cells and mitigates cluster-associated damage. These data describe a model of bacterial dissemination across the BBB shedding light on a mechanism that might contribute to CNS tuberculosis infection and facilitate treatments.

Особенности патогенетических механизмов туберкулезного перитонита в эксперименте

The prevalence of tuberculous peritonitis that has been observed in the recent decades is the result of lymphohematogenous spread of Mycobacterium tuberculosis (MBT) from lungs and other extrapulmonary sources. It is still unclear why certain organs and anatomical regions get involved in the inflammatory process during generalization of the tuberculosis infection. Why do some cases develop into peritoneal tuberculosis and other into kidney tuberculosis? Thus study aimed to investigate the pathogenesis of tuberculous peritonitis in a reproducible biological model. Tuberculous peritonitis was modeled in 18 rabbits (10 in the test group, 8 in control) by intraperitoneal inoculation of the MBT suspension. In order to suppress peritoneal macrophages and major cytokines, test group rabbits were injected with the TNFα inhibitor and iron (III) hydroxide sucrose complex before being infected, while control group rabbits received no immunosuppressive drugs. Autopsy of the control group animals revealed changes characteristic of pulmonary tuberculosis in 37.5% of cases, with no damage to other organs and systems registered. Conversely, test group rabbits had the signs of tuberculous peritonitis in their abdominal cavities. The results of this study suggest that it is the local immunity of an anatomical area that largely determines whether a secondary focus of extrapulmonary tuberculosis infection will develop there or not. For the peritoneum, a smaller pool of peritoneal macrophages and weaker cytokine production is a necessary and sufficient condition to have tuberculous peritonitis developing therein.

Genomic characterization of sporadic isolates of the dominant clone of Mycobacterium abscessus subspecies massiliense

Recent studies have characterized a dominant clone (Clone 1) of Mycobacterium abscessus subspecies massiliense (M. massiliense) associated with high prevalence in cystic fibrosis (CF) patients, pulmonary outbreaks in the United States (US) and United Kingdom (UK), and a Brazilian epidemic of skin infections. The prevalence of Clone 1 in non-CF patients in the US and the relationship of sporadic US isolates to outbreak clones are not known. We surveyed a reference US Mycobacteria Laboratory and a US biorepository of CF-associated Mycobacteria isolates for Clone 1. We then compared genomic variation and antimicrobial resistance (AMR) mutations between sporadic non-CF, CF, and outbreak Clone 1 isolates. Among reference lab samples, 57/147 (39%) of patients with M. massiliense had Clone 1, including pulmonary and extrapulmonary infections, compared to 11/64 (17%) in the CF isolate biorepository. Core and pan genome analyses revealed that outbreak isolates had similar numbers of single nucleotide polymorphisms (SNPs) and accessory genes as sporadic US Clone 1 isolates. However, pulmonary outbreak isolates were more likely to have AMR mutations compared to sporadic isolates. Clone 1 isolates are present among non-CF and CF patients across the US, but additional studies will be needed to resolve potential routes of transmission and spread.

Liposome-mediated detection of SARS-CoV-2 RNA-positive extracellular vesicles in plasma.

Introductory paragraphPlasma SARS-CoV-2 RNA may represent a viable diagnostic alternative to respiratory RNA levels that rapidly decline after infection. RT-qPCR reference assays exhibit poor performance with plasma, likely reflecting dilution and degradation of viral RNA released into the circulation, but these issues could be addressed by analyzing viral RNA packaged into extracellular vesicles (EVs). Herein we describe an assay approach where EVs directly captured from plasma are fused with reagent-loaded liposomes to sensitively amplify and detect a SARS-CoV-2 gene target. This approach accurately diagnosed COVID-19 patients, including challenging cases missed by RT-qPCR. SARS-CoV-2-positive EVs were detected at day one post-infection, and plateaued from day six to the day 28 endpoint in a non-human primate model, while 20–60 day signal durations were observed in young children. This nanotechnology approach, which uses a non-infectious sample, could thus improve COVID-19 diagnosis by extending virus detection windows to identify COVID-19 cases missed by current assays.

Clofazimine for treatment of multidrug-resistant non-tuberculous mycobacteria

Background:/QuestionNontuberculous mycobacteria (NTM) infections are increasingly detected but difficult to cure given complex drug-resistance patterns. Select U.S. centers have incorporated clofazimine in the treatment of NTM but experience is limited as procurement restrictions hamper widespread use. MethodsA prospective cohort study was performed in patients diagnosed with pulmonary or extrapulmonary NTM infection and treated with clofazimine between February 2015 and April 2019 at a tertiary referral hospital. Treatment success was defined by a combined outcome of clinical stabilization, microbiologic cure and radiologic improvement. Secondary outcomes included all-cause mortality and time to sputum culture conversion. Uni/multi-variate regression were used to define associations between pre-determined predictor variables and overall treatment outcome. ResultsOf 44 patients enrolled, 39 (89 %) received clofazimine along with a median of 3 concomitant antibiotics. Thirty-one (80 %) of patients had pulmonary NTM infection, with Mycobacterium abscessus group and Mycobacterium avium complex being the most common species groups identified. Of 36 people with evaluable outcomes, 35 (97 %) survived and 22 (58 %) had treatment success, including 12 of 19 (63 %) with Mycobacterium abscessus group. In multivariate analysis, patients with Mycobacterium abscessus group were more likely to experience treatment success (OR 18.22, 95%CI 0.972–341.43, p = 0.052), while macrolide resistance predicted a lack of treatment success (OR 0.053, 95%CI 0.003–0.841, p = 0.037). Clofazimine was well-tolerated. ConclusionAdding clofazimine to multi-class antibiotic regimens for drug-resistant NTM infection led to treatment success in the majority treated. Randomized controlled studies are needed to determine the individual impact of clofazimine within an otherwise optimized drug regimen.

Value of gamma interferon enzyme-linked immunospot assay in the diagnosis of peritoneal dialysis-associated tuberculous peritonitis

BackgroundTuberculous peritonitis is the most common form of extrapulmonary tuberculosis infection in peritoneal dialysis patients. However, diagnosing tuberculous peritonitis quickly and early has always been a challenge for nephrologists. Mycobacterium tuberculosis antigen-specific gamma interferon enzyme-linked immunospot (IFN-γ ELISPOT) assay has been widely used in the clinical diagnosis of tuberculous pleurisy and peritonitis, but its use has not been reported for uremia.MethodsThis study mainly verified the feasibility of using the M. tuberculosis antigen-specific IFN-γ ELISPOT assay in the diagnosis of continuous ambulatory peritoneal dialysis (CAPD) patients with tuberculous peritonitis. Taking M. tuberculosis culture as the gold standard, the IFN-γ ELISPOT assay was used to analyze peripheral blood and peritoneal dialysis fluid of patients, and the receiver operating characteristic (ROC) curves in patients with tuberculous peritonitis (TBP) or non-tuberculous peritonitis (NTBP) were analyzed.ResultsThe area under the receiver operating characteristic curve (AUC) was 0.927 (95% CI 0.816–1.000, P = 0.001) for the ELISPOT assay with peritoneal fluid mononuclear cells (PFMC), which was higher than that for the ELISPOT assay with peripheral blood mononuclear cells (PBMC) (0.825, 95% CI 0.6490–1.000, P = 0.011). The cutoff value for the diagnosis of TBP was 40 spot-forming cells (SFCs)/2 × 105 for the ELISPOT with PBMC, with a sensitivity of 55.6%, a specificity of 92.3%, and a diagnostic efficiency of 77.3%. The cutoff value for the diagnosis of TBP was 100 SFCs/2 × 105 for the ELISPOT on PFMC, with a sensitivity, specificity, and diagnostic efficiency 77.8%, 84.6%, and 81.8%, respectively. Parallel and serial testing algorithms appeared more accurate than single ELISPOT assays with PBMC, but ELISPOT assays with PFMC.ConclusionsThe IFN-γ release test can be used for the early diagnosis of CAPD-related TBP; compared with peripheral blood, peritoneal fluid may be a more effective and accurate medium to diagnose CAPD complicated with tuberculous peritonitis.