Phenotypic characterization of trimeric autotransporter adhesin-defective bcaC mutant of Burkholderia cenocepacia: cross-talk towards the histidine kinase BCAM0218.

Burkholderia cenocepacia is a virulent species belonging to the Burkholderia cepacia complex (Bcc) and one of the most problematic agents of chronic lung infection in cystic fibrosis patients. B. cenocepacia possesses a large panel of virulence traits that include trimeric autotransporter adhesins (TAAs). Such proteins are obligate homotrimeric anchored in the outer membrane. They are players in the adhesion events that occur between bacteria and biotic/abiotic surfaces. In this study, we constructed two insertional-mutants for TAA bcaC and Histidine kinase (HK) BCAM0218 genes, which are clustered together within the B. cenocepacia K56-2 TAA cluster. The bcaC-mutant affects B. cenocepacia adhesion to extracellular matrix proteins and red blood cells hemagglutination. BcaC contributes to enhancing B. cenocepacia K56-2 adhesion to bronchial epithelial cells. The expression of bcaC seems to affect biofilm formation negatively. Due to a BCAM0218 disruption, the bcaC expression increases significantly, indicating that they are functionally linked. The overexpression of bcaC in the BCAM0218-mutant background rescues at least part of the BcaC functions. Altogether, these findings reveal the multifunctionality of BcaC as a novel B. cenocepacia K56-2 virulence factor and postulate the involvement of a sensor HK (BCAM0218) in the control of this TAA gene.

Microbiological Status as a Factor of Airway Complications After Lung Transplantation.

BACKGROUND: Lung transplantation (LTx) is the only treatment for patients with end-stage lung disease. This procedure is associated with a risk of complications related to airway stenosis, which can be treated by means of bronchoscopic interventions (BI). Microbiological colonization may have an impact on airway complications. The aim of the study was to investigate the effect of presence of microbiological pathogens in graft among lung recipients and frequency of BI, considered as the indicator of severe complications. MATERIALS AND METHODS: The study design was single-center retrospective cohort research; cases of 116 patients with complete microbiological data who underwent LTx from April 2013 to June 2019 were reviewed (70.3% of transplanted patients). All statistical analyses were performed with SPSS version 25.0 and R 3.5.3. For analyses involving the number of bronchoscopy interventions, univariate and multivariate Poisson regression were used. Interaction effect of variables in multivariate Poisson regression was assessed with partial response plot. RESULTS: The mean number of pathogens colonizing each patient was approximately 4.66 (range, 0 to 19) with Candida albicans (n = 42, 36.2%), Aspergillus spp. (n = 33, 28.4%), Pseudomonas aeruginosa (n = 32, 27.59%), and methicillin-sensitive Staphylococcus aureus (MSSA) (n = 29, 25%) being the most prominent. Microbiological agents causing the greatest increase in the risk of intervention are as follows: Proteus mirabilis by 3.84 times, Aspergillus spp. by 3.53 times, and Stenotrophomonas maltophilia by 3.09 times. Burkholderia multivorans, Enterococcus spp., and Klebsiella spp. do not have a statistically significant impact on the number of BI. CONCLUSIONS: Some pathogens increase the frequency of complications, which are associated with deterioration of the general condition. Therefore, patients should be monitored for the presence of pathogens in the airways.

Risk of Bronchial Dehiscence in Lung Transplant Recipients With Carbapenemase-producing Klebsiella.

BACKGROUND: Klebsiella pneumoniae is commonly isolated after lung transplantation. This study observed an increase in bronchial complications after an outbreak of Klebsiella pneumoniae carbapenemase-producing Klebsiella (KPC-KP). METHODS: The study enrolled 173 patients who had undergone bilateral lung transplantation between 2012 and 2018 to examine the association between bronchial complications after lung transplantation and KPC-KP. The KPC-KP group was defined as patients whose isolates from sputum or bronchoalveolar lavage fluid were positive for KPC-KP. The presence of bronchial complications was defined as a positive finding on bronchoscopy in accordance with the criteria of the International Society for Heart and Lung Transplantation. Risk factors for bronchial complications were analyzed. RESULTS: KPC-KP was identified in 29 patients (16.8%), and bronchial dehiscence was observed in 13 patients (7.5%). Smoking (odds ratio [OR], 5.690; 95% confidence interval [CI], 1.106- to 9.260; P = .037), the presence of KPC-KP (OR, 5.360; 95% CI, 1.380 to 20.810; P = .015), and bronchial necrosis (OR, 7.009; 95% CI, 1.811 to 27.124; P = .005) were associated with bronchial dehiscence in a multivariate logistic regression model. CONCLUSIONS: The presence of KPC-KP in lung-transplant recipients significantly increased the risk of bronchial dehiscence, independent of bronchial necrosis. Thus, patients with KPC-KP require greater surveillance and follow-up bronchoscopy, irrespective of the presence or absence of bronchial necrosis or the overall patient condition.

Unusual Presentation of Severe Endobronchial Obstruction Caused by Cryptococcus gattii in a Child.

Disease caused by Cryptococcus gattii typically manifests as meningoencephalitis or pulmonary nodules. Endobronchial lesions are rare, and most cases are caused by Cryptococcus neoformans. We describe here a case of endobronchial disease in a child caused by C gattii. The disease spectrum in this patient was notable for the discovery of anti-granulocyte macrophage colony-stimulating factor autoantibodies.

Multidrug resistant lymph node fistula tracheobronchial tuberculosis: A case report.

RATIONALE: The patient in this case report has been diagnosed with multidrug resistant lymph node fistula tracheobronchial tuberculosis (TBTB). The PubMed was searched using the keywords "Tuberculosis, Multidrug-Resistant", "Tuberculosis", and "Bronchial Fistula", and the results yielded no similar case reports. Therefore, this report helps us to explore more on the causes of multidrug resistance and formation of lymph node fistula, as well as associated treatment strategies. PATIENT CONCERNS: A 15-year old Tibetan girl who was previously treated in the local Hospital for Infectious Diseases for repeated TBTB demonstrated poor treatment outcomes, and so was further diagnosed in our hospital. After standard treatments, the cough and expectoration of the girl showed improvement, and mycobacterium culture showed negative results. Thoracic CT showed local compression of the right bronchus, and disappearance of stenosis. Bronchoscopy showed that the fistula was closed and healed. DIAGNOSES: Multidrug resistant lymph node fistula TBTB. INTERVENTIONS: Antituberculosis drugs such as pyrazinamide (0.75 g/time, twice per day), moxifloxacin (0.4 g per day), protionamide enteric-coated tablets (0.2 g/time, 3 times per day), pasiniazide tablets (0.3 g/time, 3 times per day), and capreomycin (0.75 g per day) were orally administered. The treatment included an 8-month intensive treatment phase and a 12-month consolidation phase. Bronchoscopic local injection combined with cryotherapy was also conducted. OUTCOMES: Bronchoscopy showed that the fistula was closed and healed, mycobacterium culture showed negative results, and thoracic CT showed local compression of the right bronchus, disappearance of stenosis after treatment. LESSONS: (1) This girl had a history of long-term oral intake of antituberculosis drugs, but the treatment effectiveness remained poor. Therefore, resistance to tuberculosis can be considered, and also mycobacterium culture and drug sensitivity tests should be considered. After these, the treatment strategies should be adjusted accordingly.(2) TBTB should be further classified by analyzing under the bronchoscope to decide the best treatment strategy accordingly.

A 76-Year-Old Woman With Incidental Right Middle Lobe Atelectasis.

CASE PRESENTATION: A 76-year-old nonsmoking woman visiting from Honduras for the last 6 months with no known medical history originally presented to the ED complaining of abdominal pain. While in the ED, an incidental right middle lobe collapse was found on CT abdomen scan. Review of systems was positive for a chronic productive cough with white sputum for 3 years. She denied association with fevers, chills, night sweats, hemoptysis, appetite changes, or weight loss.

Deterioro clínico por Exophiala dermatitidis en un paciente con fibrosis quística / Clinical Deterioration Due to Exophiala Dermatitidis in a Patient with Cystic Fibrosis

No disponible

Hilar asymmetry in endobronchial tuberculosis patients: An often-overlooked clue.

BACKGROUND: Endobronchial tuberculosis (EBTB) is a challenging diagnosis because of its varied clinical and radiological manifestations. Hilar asymmetry on chest radiograph (CXR) may be found in patient with EBTB but is often overlooked, which may lead to delayed diagnosis. CASE REPORT: We present five cases with EBTB. Clinicians failed to identify unilateral hilar abnormalities on CXR, and these patients were treated initially for pharyngitis, bronchitis, or pneumonia with no improvement. Subsequently, they visited the pulmonary clinic and bronchoscopy revealed endobronchial lesions and microbial/histopathological evidence of tuberculous infection consistent with EBTB. Anti-tuberculosis therapy resulted in complete clinical resolution in four of the five patients; one patient had persistent bronchial stenosis. CONCLUSION: Hilar asymmetry on CXR may occur with EBTB and may suggest this diagnosis in the appropriate clinical setting. Bronchoscopy has an important role in establishing the final diagnosis.

Pulmonary pythiosis in a canine patient.

A Staffordshire terrier presented for evaluation of a chronic, nonproductive cough that was unresponsive to antibiotic therapy. A large mass identified in the pulmonary hilum was most consistent with tracheobronchial lymphadenopathy on radiographic and computed tomography (CT) images. Bronchoscopy confirmed a mass compressing the dorsal portion of the intrathoracic trachea. Bronchoscopic biopsies of the tracheal mass revealed necrosuppurative and eosinophilic inflammation with intralesional Pythium insidiousum hyphae. Pythiosis should be included as a differential diagnosis for tracheobronchial lymphadenopathy and bronchopneumopathy in dogs, especially when the patient is from or has visited a region endemic for Pythium insidiosum.

Defining lower airway bacterial infection in children with chronic endobronchial disorders.

BACKGROUND: Differentiating lower airway bacterial infection from possible upper airway contamination in children with endobronchial disorders undergoing bronchoalveolar lavage (BAL) is important for guiding management. A diagnostic bacterial load threshold based on inflammatory markers has been determined to differentiate infection from upper airway contamination in infants with cystic fibrosis, but not for children with protracted bacterial bronchitis (PBB), chronic suppurative lung disease (CSLD), or bronchiectasis. METHODS: BAL samples from children undergoing bronchoscopy underwent quantitative bacterial culture, cytologic examination, and respiratory virus testing; a subset also had interleukin-8 examined. Geometric means (GMs) of total cell counts (TCCs) and neutrophil counts were plotted by respiratory pathogen bacterial load. Logistic regression determined associations between age, sex, Indigenous status, antibiotic exposure, virus detection and bacterial load, and elevated TCCs (>400 × 103 cells/mL) and airway neutrophilia (neutrophils >15% BAL leukocytes). RESULTS: From 2007 to 2016, 655 children with PBB, CSLD, or bronchiectasis were enrolled. In univariate analyses, Indigenous status and bacterial load ≥105 colony-forming units (CFU)/mL were positively associated with high TCCs. Viruses and bacterial load ≥104 CFU/mL were positively associated with neutrophilia; negative associations were seen for Indigenous status and macrolides. In children who had not received macrolide antibiotics, bacterial load was positively associated in multivariable analyses with high TCCs at ≥104 CFU/mL and with neutrophilia at ≥105 CFU/mL; GMs of TCCs and neutrophil counts were significantly elevated at 104 and 105 CFU/mL compared to negative cultures. CONCLUSIONS: Our findings support a BAL threshold ≥104 CFU/mL to define lower airway infection in children with chronic endobronchial disorders.

Report of 12 cases with tracheobronchial mucormycosis and a review.

OBJECTIVES: Tracheobronchial mucormycosis is a rare and invasive pulmonary mucormycosis involving the tracheobronchial tree. DATA SOURCE: At a 3500-bed tertiary care center. STUDY SELECTION: This was a retroactive study of 12 cases of tracheobronchial mucormycosis diagnosed in our hospital, and 48 cases that were previously reported in the English literature. RESULTS: Rhizopus was the predominant species of pathogen (66.7%). Primary bronchus was the most frequently involved location (38.2%), and upper lobes (51% of cases) were a predilection. Obstructive necrosis and mucosal necrosis were the most common pathological forms (40% and 34.5%, respectively). Fever (59.3%), cough (59.3%), dyspnea (40.7%) and hemoptysis (30.5%) were the most common symptoms. 51.4% patients had rales, 40% had moist rales and 28.6% had negative physical findings. Ninety-five percent patients had immunosuppressive diseases. Diabetes mellitus (66.7%), diabetes ketoacidosis (21.7%), corticosteroid therapy (20%) and kidney insufficiency (18.3%) were the most common predisposing factors. 13.2% had neutropenia which was mostly among the non-diabetic patients (P = .006). Endobronchial lesion of 23.2% had imaging reports with 33.9% exhibiting single mass. Pathological diagnosis of 76.7% used the transbronchial biopsy. The most frequent antifungal therapies were intravenous amphotericin B (79.7%), surgery (33.3%) and surgery combined with amphotericin B therapy (28.3%). Overall in-hospital mortality was 52.5%, with hemoptysis (P = .017), dyspnea at presentation (P = .022) and angioinvasion (P = .03) as independent risk prognostic factors. In contrast, surgery (P = .003) was an independent protection prognostic factor. CONCLUSIONS: Tracheobronchial mucormycosis is a rare but severe disease with high mortality because of its nonspecific clinical presentations and variable predisposing factors.

Characteristics and clinical role of bronchoscopy in diagnosis of childhood endobronchial tuberculosis.

BACKGROUND: Endobronchial tuberculosis (EBTB) is the most frequent complication of primary pulmonary tuberculosis (PTB) in children. The aim of the study was to analyze characteristics and clinical role of bronchoscopy in diagnosis of childhood EBTB. METHODS: A retrospective, descriptive study was undertaken in 157 children with EBTB undergone flexible bronchoscopy (FB) between January 2006 and June 2014. RESULTS: The median age of the enrolled patients was 3.4 years, with 73.2% of patients under five years old. The most common subtype was tumorous type (145/157, 92.4%). If only involved bronchus were considered, the common affected sites were right middle lobe bronchus (49/228, 21.5%), left upper lobe bronchus (41/228, 18.0%), right upper lobe bronchus (41/228, 18.0%), right main bronchus (35/228, 15.4%), respectively. Children younger than five years old were at higher risk to have multiple endobronchial lesions (P=0.044), with an odds ratio of 2.313 (95% confidence interval: 1.009-5.299). Before the bronchoscopy, only 16 (10.2%) patients were highly suspected of EBTB, while the others were diagnosed as PTB without EBTB (69.4%), or misdiagnosed as pneumonia or foreign body aspiration (20.4%) on admission. CONCLUSIONS: The patients under five years old are at high risk to progress to EBTB and have multiple endobronchial lesions. The most frequent subtype of EBTB in children is tumorous type. The lesions are seen in the right bronchial system more frequently. FB should be performed to detect the endobronchial lesions in suspected patients as soon as possible.

Concurrent central nervous system and endobronchial tuberculosis mimicking a metastatic lung cancer.

BACKGROUND AND AIMS: Early diagnosis and treatment of central nervous system tuberculosis are important because of high mortality and morbidity. Airways must be carefully evaluated in differential diagnosis. METHODS: We present a rare case of intracranial-endobronchial tuberculosis mimicking lung cancer with brain metastasis. RESULTS: A vegetative mass lesion, confirmed as necrotic granulomatous inflammation, originating from the entrance of the right upper lobe entry, was coagulated and extracted by argon plasma coagulation and cryotherapy to prevent permanent upper lobe atelectasis. Mycobacterium tuberculosis complex was detected in bronchoscopic material. A four-drug initial anti-tuberculous treatment regimen was given in 2 months. The upper lobe atelectasis was resolved at the fourth month of therapy despite upper lobar bronchus patency. The patient was doing well and completed the two-drug maintenance therapy of 7 months with complete resolution. CONCLUSION: In such cases, tissue diagnosis should be achieved as early as possible and anti-tuberculous treatment was commenced along with advanced interventional techniques.