Inhalation of Stachybotrys chartarum Fragments Induces Pulmonary Arterial Remodeling.

Stachybotrys chartarum is a fungal contaminant within the built environment and a respiratory health concern in the United States. The objective of this study was to characterize the mechanisms influencing pulmonary immune responses to repeatedly inhaled S. chartarum. Groups of B6C3F1/N mice repeatedly inhaled viable trichothecene-producing S. chartarum conidia (strain A or strain B), heat-inactivated conidia, or high-efficiency particulate absolute-filtered air twice per week for 4 and 13 weeks. Strain A was found to produce higher amounts of respirable fragments than strain B. Lung tissue, serum, and BAL fluid were collected at 24 and 48 hours after final exposure and processed for histology, flow cytometry, and RNA and proteomic analyses. At 4 weeks after exposure, a T-helper cell type 2-mediated response was observed. After 13 weeks, a mixed T-cell response was observed after exposure to strain A compared with a T-helper cell type 2-mediated response after strain B exposure. After exposure, both strains induced pulmonary arterial remodeling at 13 weeks; however, strain A-exposed mice progressed more quickly than strain B-exposed mice. BAL fluid was composed primarily of eosinophils, neutrophils, and macrophages. Both the immune response and the observed pulmonary arterial remodeling were supported by specific cellular, molecular, and proteomic profiles. The immunopathological responses occurred earlier in mice exposed to high fragment-producing strain A. The rather striking induction of pulmonary remodeling by S. chartarum appears to be related to the presence of fungal fragments during exposure.

Successful Conservative Treatment of Mycotic Pulmonary Artery Aneurysms Caused by MRSA Bacteremia.

Mycotic pulmonary artery aneurysms (MPAAs) are rare and life-threatening with currently no recommended treatment strategies. In this report, we describe a successfully treated case of ventricular septal defect in an 11-month-old girl who developed bacteremia, infective endocarditis, and MPAA caused by methicillin-resistant Staphylococcus aureus (MRSA). We first started vancomycin, gentamycin, and panipenem-betamipron for infective endocarditis but switched to teicoplanin and arbekacin on day 3 after initiating treatment because bacteremia persisted, and vancomycin minimum inhibitory concentration was relatively high at 2 mg/L. Although we added clindamycin on day 5 and fosfomycin on day 7, MRSA bacteremia persisted, and we finally added daptomycin at 10 mg/kg per day on day 8, whereupon the bacteremia subsided within a day. Although the bacteremia subsided, the patient developed septic pulmonary embolisms and septic arthritis on her left knee. We continued daptomycin but switched the concomitant drug to linezolid, trimethoprim-sulfamethoxazole, and rifampicin on day 11. After several repeats of puncture and lavage of her knee joint, she became afebrile on day 16. Computed tomography scans taken on day 32 revealed right pulmonary artery MPAAs. She was treated with long-term multidrug therapy, and MPAAs were absent on subsequent computed tomography scans on day 184. Multidrug therapy mainly based on daptomycin could be a possible salvage therapy for refractory MRSA bacteremia with high vancomycin minimum inhibitory concentration. Conservative treatment should be selectively considered as a treatment option for clinically stable MPAA instead of surgical and endovascular treatment.

Can intestinal microbiota and circulating microbial products contribute to pulmonary arterial hypertension?

Pulmonary arterial hypertension (PAH) is a fatal disease with a median survival of only 5-7 yr. PAH is characterized by remodeling of the pulmonary vasculature causing reduced pulmonary arterial compliance (PAC) and increased pulmonary vascular resistance (PVR), ultimately resulting in right ventricular failure and death. Better therapies for PAH will require a paradigm shift in our understanding of the early pathophysiology. PAC decreases before there is an increase in the PVR. Unfortunately, present treatment has little effect on PAC. The loss of compliance correlates with extracellular matrix remodeling and fibrosis in the pulmonary vessels, which have been linked to chronic perivascular inflammation and immune dysregulation. However, what initiates the perivascular inflammation and immune dysregulation in PAH is unclear. Alteration of the gut microbiota composition and function underlies the level of immunopathogenic involvement in several diseases, including atherosclerosis, obesity, diabetes mellitus, and depression, among others. In this review, we discuss evidence that raises the possibility of an etiologic role for changes in the gut and circulating microbiome in the initiation of perivascular inflammation in the early pathogenesis of PAH.

Sepsis Caused by Bacterial Colonization of Migrated Distal Ventriculoperitoneal Shunt Catheter into the Pulmonary Artery: A First Case Report and Literature Review.

BACKGROUND: Migration of distal ventriculoperitoneal (VP) shunt catheter into another body part has been described as a potentially serious surgical complication. We present the first case of sepsis caused by transcardial and pulmonary migration of a distal catheter into the heart and pulmonary artery, which was subsequently colonized by Klebsiella pneumoniae. CASE REPORT: A 56-year-old man underwent VP shunt insertion for hydrocephalus that developed after the surgery for intracranial meningioma. Three years later, he was admitted to department for infectious diseases because of persistent fever. Klebsiella pneumoniae was isolated from the blood cultures. Computed tomography (CT) of the thorax showed migration of the distal catheter into the heart and pulmonary artery. The migrated shunt catheter was retrieved without any complication with the assistance of a cardiovascular surgeon; microbiologic analysis confirmed that the catheter was colonized with K. pneumoniae. We decided to delay new VP shunt placement because of the positive blood cultures, and 3 weeks after the surgery, the patient was without signs of increased intracranial pressure and without any heart problems. CONCLUSION: Migration of a distal VP shunt catheter into the heart should be considered in patients with a previously placed VP shunt presenting with cardiopulmonary problems, arrhythmia, and/or fever. Neurosurgeons should be involved as soon as possible, and a multidisciplinary approach is warranted.

Subacute Aerococcus urinae Infective Endocarditis With Mycotic Aneurysms in a Pediatric Patient: Case Report and Literature Review.

Aerococcus urinae has been found to cause urinary tract infection in elderly patients and has been reported as a rare cause of infective endocarditis associated with significant morbidity and death in adults. However, information regarding its occurrence in children is lacking. We report here the case of a pediatric patient with subacute A urinae infective endocarditis with mycotic aneurysms.

Patent Ductus Arteriosus with Infective Vegetations in Grandmultipara.

Patent ductus arteriosus (PDA) usually presents during childhood, less frequently in adolescence, and rarely in late adulthood. The usual mode of presentation is left ventricular failure and respiratory symptoms. Here is a case of a female with patent ductus arteriosus, who was apparently in quite good state of health and gave birth to six offsprings without herself having any problem. At the age of 40, she presented with infected vegetations at the site of PDA, causing fever and clinical signs of PDA, confirmed by echocardiography.

Enhanced Permeability and Retention-like Extravasation of Nanoparticles from the Vasculature into Tuberculosis Granulomas in Zebrafish and Mouse Models.

The enhanced permeability and retention (EPR) effect is the only described mechanism enabling nanoparticles (NPs) flowing in blood to reach tumors by a passive targeting mechanism. Here, using the transparent zebrafish model infected with Mycobacterium marinum we show that an EPR-like process also occurs allowing different types of NPs to extravasate from the vasculature to reach granulomas that assemble during tuberculosis (TB) infection. PEGylated liposomes and other NP types cross endothelial barriers near infection sites within minutes after injection and accumulate close to granulomas. Although ∼100 and 190 nm NPs concentrated most in granulomas, even ∼700 nm liposomes reached these infection sites in significant numbers. We show by confocal microscopy that NPs can concentrate in small aggregates in foci on the luminal side of the endothelium adjacent to the granulomas. These spots are connected to larger foci of NPs on the ablumenal side of these blood vessels. EM analysis suggests that NPs cross the endothelium via the paracellular route. PEGylated NPs also accumulated efficiently in granulomas in a mouse model of TB infection with Mycobacterium tuberculosis, arguing that the zebrafish embryo model can be used to predict NP behavior in mammalian hosts. In earlier studies we and others showed that uptake of NPs by macrophages that are attracted to infection foci is one pathway for NPs to reach TB granulomas. This study reveals that when NPs are designed to avoid macrophage uptake, they can also efficiently target granulomas via an alternative mechanism that resembles EPR.

Rasmussen aneurysm: A rare but not gone complication of tuberculosis.

This report describes the case of a 30-year-old homeless man from Pereira, Colombia with tuberculosis, who presented with massive hemoptysis and associated aneurysm of the left upper lobe (Rasmussen aneurysm). Computed tomography angiography with three-dimensional reconstruction confirmed the aneurysm, and embolization was performed successfully.

A successful aggressive surgical and medical approach to pulmonary artery obstruction due to Mycobacterium abscessus infection post lung transplantation.

Mycobacterium abscessus infection following lung transplantation has historically been associated with poor outcomes. We report a case of bilateral lung retransplantation complicated by obstruction of the right pulmonary artery secondary to M. abscessus mycotic aneurysm. Aggressive surgical management, including reconstruction of the right pulmonary artery, was undertaken with prolonged antimicrobial therapy. Thirty-six months later, antibiotics have been discontinued and the patient has stable soft tissue chest wall disease with good graft function. Mortality and morbidity associated with M. abscessus infection is considerable but this case illustrates that with aggressive early management, outcomes may be favorable.

Unusual synchronous liver and brain abscesses infected by rare Aerococcus viridians in a patient with pulmonary arteriovenous malformations on FDG PET/CT: A case report and literature review.

RATIONALE: Pulmonary arteriovenous malformations (PAVMs) complicated with multiple organ abscesses is an uncommon manifestation. Because of the low incidence of the disease, F-18 fluorodeoxyglucose positron emission tomography with computed tomography (F-FDG PET/CT) imaging studies for PAVMs complicated with multiple organ abscesses are scarce. PATIENT CONCERNS: We report a case of a 54-year-old man presenting with PAVMs complicated with synchronous multiple organ abscesses founded by F-FDG PET/CT. F-FDG PET/CT revealed tortuous stripes and mass opacities with no significant FDG uptake in the left upper lung lobe. However, hypermetabolic lesions located in the anterior inferior segment of right hepatic lobe [with maximum standardized uptake value (SUVmax) of 10.7], and in the right basal ganglia with SUVmax of 14.1 were found by F-FDG PET/CT. DIAGNOSES: A diagnosis of synchronous liver and brain abscesses infected by rare Aerococcus viridans was determined by tissue culture. INTERVENTIONS: Vancomycin was provided intravenously, and oral linezolidate tablets were prescribed for anti-inflammatory treatment for 1 month. Liver and head magnetic resonance imaging was performed during the follow-up. OUTCOMES: The lesion in the right basal ganglia was reduced, and the lesion in the right liver had disappeared, indicating the lesions were abscesses. LESSONS: The present case indicated that the possibility of abscesses should be considered with patients with PAVMs, and whole-body F-FDG PET/CT is suggested to identify possible accompanying abscesses in multiple organs for PAVMs patients.

Infected pulmonary aneurysm following pulmonary artery banding.

A 1-month-old girl, diagnosed with a common atrioventricular canal, moderate atrioventricular valvular regurgitation, and pulmonary hypertension, underwent pulmonary artery banding. Postoperatively, methicillin-resistant Staphylococcus aureus wound infection was treated with antibiotics. One month later, emergency surgery was performed for oozing rupture of an infected pulmonary aneurysm. The pulmonary aneurysm was completely resected, the banding tape was removed, and pulmonary angioplasty was performed to create pulmonary stenosis without using foreign material. Methicillin-resistant Staphylococcus aureus was cultured from the resected tissues and banding tape. The patient was discharged after antibiotic administration. Correction was performed at 1 year of age, and she remains well.

Infective endocarditis of main pulmonary artery in tetralogy of Fallot: "Transesophageal echocardiography adds lease of life".

Infective endocarditis is a rare occurrence in the main pulmonary artery trunk and even rarer in tetralogy of Fallot.

Pulmonary mycotic pseudo-aneurysm with a prior history of ventricular septal defect. Case report with review of literature.

In general aneurysms of the pulmonary arteries are less frequent than intracranial, aortic or other vascular locations. Infectious causes include bacteria such as Staphylococcus sp and Streptococcus sp, mycobacteria, Treponema pallidium (syphilis) and rarely fungi. We report a 7 year old female with two right-sided parahilar pseudo-aneurysm of fungal origin with a prior history of ventricular septal defect. Pulmonary mycotic pseudo-aneurysms are very rare and require a high suspicion to diagnose. If a patient is still symptomatic for fever and cough for a long time, and consolidation on x-ray is not improving on antibiotics, contrast-enhanced computed tomography is indicated. It can be suspected that the "friable mass attached to ventricular septal defect patch" was a source of fungeal emboli to pulmonary arteries thus giving weight to the infective endocarditis etiology. A prior history of ventricular septal defect repair could favour fungal endocarditis.

Interventional therapeutic strategy for hemoptysis originating from infectious pulmonary artery pseudoaneurysms.

This study reports 6 cases of hemoptysis originating from infectious pulmonary artery pseudoaneurysms (PAPs). Selective pulmonary angiography revealed PAPs in 5 cases, and segmental pulmonary artery embolization was performed using coils and gelatin sponge particles. Systemic arterial embolization also was performed in 5 cases because of inadequate initial control or for shunts from systemic to pulmonary arteries. At a median follow-up time of 9 months (range, 25 d to 25 mo), no recurrence occurred, although 2 patients died of respiratory failure. Segmental artery embolization combined with systemic artery embolization may be useful in patients with hemoptysis secondary to PAPs.

Two- and live/real time three-dimensional transthoracic echocardiographic assessment of infective endocarditis of a valved pulmonary conduit.

We describe the use of a nonstandard left infraclavicular approach in making the diagnosis of an infected valved conduit with two-dimensional transthoracic echocardiography. The patient was an adult with tetralogy of Fallot and pulmonary atresia who had undergone multiple surgical repair procedures. The initial diagnosis of infective endocarditis was made by transesophageal echocardiography. Both techniques demonstrated a single, large vegetation in the conduit. Live/real time three-dimensional transthoracic echocardiography, on the other hand, provided further information by demonstrating several additional vegetations in the conduit and more comprehensively assessed their size by enabling measurement of their azimuthal dimensions and volumes. The patient was treated with antibiotics with complete resolution of the vegetations.

Pulmonary artery pseudoaneurysm caused by Streptococcus constellatus.

We report a rare case of mycotic pulmonary artery pseudoaneurysm (PAP) secondary to a lung abscess due to Streptococcus constellatus. PAP was confirmed by the pathological findings of the pseudoaneurysm, the presence of bacteria, and the microbiological analysis. PAP is uncommon, but it is important to recognize this condition because PAP can lead to fatal hemoptysis.

[Infective endocarditis complicating patent ductus arteriosus: emergency surgical treatment of two cases]. / Endocardite infectieuse compliquant une persistance du canal artériel et opérée en urgence : à propos de deux observations.

Infective endocarditis is a rare complication of patent ductus arteriosus nowadays. About two patients, aged 7 and 5 years old, we diagnosed and treated a patent ductus arteriosus complicated with an infective vegetative endocarditis with a risk of pulmonary embolism. We report in this observation this clinical and surgical experience.