Invasive Pulmonary Aspergillosis.

Invasive pulmonary aspergillosis (IPA) remains difficult to diagnose and to treat. Most common risk factors are prolonged neutropenia, hematopoietic stem cell or solid organ transplantation, inherited or acquired immunodeficiency, administration of steroids or other immunosuppressive agents including monoclonal antibodies and new small molecules used for cancer therapy. Critically ill patients are also at high risk of IPA. Clinical signs are unspecific. Early computed tomography (CT)-scan identifies the two main aspects, angioinvasive and airway invasive aspergillosis. Although CT-scan findings are not fully specific they usually allow early initiation of therapy before mycological confirmation of the diagnosis. Role of 18F-fludeoxyglucose positron emission tomography with computed tomography (18F-FDG PET/CT) is discussed. Confirmation is based on microscopy and culture of respiratory samples, histopathology in case of biopsy, and importantly by detection of Aspergillus galactomannan using an immunoassay in serum and bronchoalveolar lavage fluid. Deoxyribonucleic acid detection by polymerase chain reaction is now standardized and increases the diagnosis yield. Two point of care tests detecting an Aspergillus glycoprotein using a lateral flow assay are also available. Mycological results allow classification into proven (irrespective of underlying condition), probable or possible (for cancer and severely immunosuppressed patients) or putative (for critically ill patients) IPA. New antifungal agents have been developed over the last 2 decades: new azoles (voriconazole, posaconazole, isavuconazole), lipid formulations of amphotericin B (liposomal amphotericin B, amphotericin B lipid complex), echinocandins (caspofungin, micafungin, anidulafungin). Results of main trials assessing these agents in monotherapy or in combination are presented as well as the recommendations for their use according to international guidelines. New agents are under development.

Antimicrobial susceptibility and impact of macrolide antibiotics on Moraxella catarrhalis in the upper and lower airways of children with chronic endobronchial suppuration.

INTRODUCTION: Moraxella catarrhalis is an important but insufficiently studied respiratory pathogen. AIM: To determine antibiotic susceptibility and impact of recent antibiotics on M. catarrhalis from children with chronic endobronchial suppuration. METHODOLOGY: We cultured nasopharyngeal (NP) swabs and bronchoalveolar lavage (BAL) fluids collected from children who were prospectively enrolled in studies of chronic cough and had flexible bronchoscopy performed. Recent ß-lactam or macrolide antibiotic use was recorded. M. catarrhalis isolates stored at -80 °C were re-cultured and susceptibility determined to a range of antibiotics including the macrolide antibiotic erythromycin. RESULTS: Data from concurrently collected NP and BAL specimens were available from 547 children (median age 2.4 years) enrolled from 2007 to 2016. M. catarrhalis NP carriage was detected in 149 (27  %) children and lower airway infection (≥104 c.f.u. ml-1 BAL) in 67 (12  %) children. In total, 91  % of 222 M. catarrhalis isolates were ß-lactamase producers, and non-susceptibility was high to benzylpenicillin (98 %), cefaclor (39 %) and cotrimoxazole (38 %). Overall, >97  % isolates were susceptible to cefuroxime, chloramphenicol, erythromycin and tetracycline; three isolates were erythromycin-resistant (MIC >0.5 mg l-1). Recent macrolide antibiotics (n=152 children, 28 %) were associated with significantly reduced M. catarrhalis carriage and lower airway infection episodes compared to children who did not receive macrolides; odds ratios 0.19 (95  % CI 0.10-0.35) and 0.15 (0.04-0.41), respectively. CONCLUSION: Despite the frequent use of macrolides, few macrolide-resistant isolates were detected. This suggests a fitness cost associated with macrolide resistance in M. catarrhalis. Macrolide antibiotics remain an effective choice for treating M. catarrhalis lower airway infection in children with chronic endobronchial suppuration.

Managing invasive aspergillosis in haematological patients in the era of resistance polymerase chain reaction and increasing triazole resistance: A modelling study of different strategies.

OBJECTIVES: Triazole resistance in Aspergillus spp. is emerging and complicates prophylaxis and treatment of invasive aspergillosis (IA) worldwide. New polymerase chain reaction (PCR) tests on broncho-alveolar lavage (BAL) fluid allow for detection of triazole resistance at a genetic level, which has opened up new possibilities for targeted therapy. In the absence of clinical trials, a modelling study delivers estimates of the added value of resistance detection with PCR, and which empiric therapy would be optimal when local resistance rates are known. DESIGN: A decision-analytic modelling study was performed based on epidemiological data of IA, extended with estimated dynamics of resistance rates and treatment effectiveness. Six clinical strategies were compared that differ in use of PCR diagnostics (used vs not used) and in empiric therapeutic choice in case of unknown triazole susceptibility: voriconazole, liposomal amphotericin B (LAmB) or both. Outcome measures were proportion of correct treatment, survival and serious adverse events. RESULTS: Implementing aspergillus PCR tests was projected to result in residual treatment-susceptibility mismatches of <5% for a triazole resistance rate up to 20% (using voriconazole). Empiric LAmB outperformed voriconazole at resistance rates >5-20%, depending on PCR use and estimated survival benefits of voriconazole over LAmB. Combination therapy of voriconazole and LAmB performed best at all resistance rates, but the advantage over the other strategies should be weighed against the expected increased number of drug-related serious adverse events. The advantage of combination therapy over LAmB monotherapy became smaller at higher triazole resistance rates. CONCLUSIONS: Introduction of current aspergillus PCR tests on BAL fluid is an effective way to increase the proportion of patients that receive targeted therapy for IA. The results indicate that close monitoring of background resistance rates and adverse drug events are important to attain the potential benefits of LAmB. The choice of strategy ultimately depends on the probability of triazole resistance, the availability of PCR and individual patient characteristics.

Tailoring Empirical Antimicrobial Therapy in Subjects With Ventilator-Associated Pneumonia With a 10-Hour E-Test Approach.

BACKGROUND: In a previous study of subjects suspected of having ventilator-associated pneumonia, a rapid susceptibility testing approach by using ETEST (BioMérieux) strips directly applied to bronchoalveolar lavage samples provided valuable information at hour 24. The primary objective of this study was to assess a new direct specimen testing by using an even more-rapid E-test approach (at hour 10), which could promote an early de-escalation of the antimicrobial therapy. METHODS: Twenty-eight subjects with ventilator-associated pneumonia admitted to a medical ICU were prospectively included. In parallel with standard routine methods, E-test strips were directly applied onto agar plates seeded with bronchoalveolar lavage samples and were analyzed after 10 h of incubation. E-test results were used to identify potential drug choices by simulating clinical decision making if the microscopy results had been available at the point of care. These choices were analyzed for concordance with the narrowest adequate antimicrobial therapy according to the Minimum Inhibitory Concentrations (MICs) provided by the reference method (ie, the laboratory routine diagnostic). RESULTS: At hour 10, direct specimen testing was readable in 18 of 28 bronchoalveolar lavage samples (64%). Total agreement between the 10-h direct specimen testing approach and the laboratory routine diagnostic approach was 90%, with a sensitivity of 83% and a specificity of 95%, with 8% major errors and 3% very major errors. The concordance between the 2 tests was very good (kappa = 0.79). If the 10-h E-test results were taken into account, then an early de-escalation strategy would have been possible in 10 of 18 cases (55%) at hour 10. CONCLUSIONS: This rapid susceptibility testing approach provided early (10 h) and valuable information that could lead to an early adjustment of empirical antimicrobial treatment in a ventilator-associated pneumonia setting. (ClinicalTrials.gov registration NCT01266863.).

Successful treatment of invasive pulmonary aspergillosis caused by Aspergillus felis, a cryptic species within the Aspergillus section Fumigati: A case report.

Aspergillus species are a major cause of life-threatening infections in immunocompromised hosts, and the most common pathogen of invasive aspergillosis is Aspergillus fumigatus. Recently, the development of molecular identification has revealed cryptic Aspergillus species, and A. felis is one such species within the Aspergillus section Fumigati reported in 2013. We describe a case of invasive pulmonary aspergillosis caused by A. felis in a 41-year-old Japanese woman diagnosed with myelodysplastic syndrome. She presented with fever 19 days after undergoing autologous peripheral blood stem cell transplantation and was clinically diagnosed with invasive pulmonary aspergillosis. Bronchoscopy and bronchoalveolar lavage were performed for definitive diagnosis. The ß-tubulin genes of the mold isolated from the bronchoalveolar lavage fluid, and sequenced directly from the PCR products using a primer pair were found to have 100% homology with A. felis. We successfully treated the patient with echinocandin following careful susceptibility testing. To the best of our knowledge, this is the first published case reporting the clinical course for diagnosis and successful treatment of invasive aspergillosis by A. felis.

Effect of Lidocaine 2% on Bacterial Culture of Bronchial Fluid.

OBJECTIVE: To evaluate the action of 2% lidocaine on the culture results of bronchial fluid in patients suspected of having lower respiratory tract infections. STUDY DESIGN: Cross-sectional analytical study. PLACE AND DURATION OF STUDY: Shahid Sadoughi Hospital, Yazd, Iran, from November 2014 to November 2015. METHODOLOGY: Patients suspected of lower respiratory tract infections referred to bronchoscopy unit of the Hospital were included. Those with incomplete questionnaire and bronchoscopy contraindication were excluded. Bronchial fluid was aspirated before and after local application of 2% lidocaine and cultured, according to the suspected clinical diagnosis. Finally, statistical analysis was performed using SPSS software, version 17.0. For statistical comparisons, McNemar's test was used. Level of significance was kept at p <0.05. RESULTS: The mean age of the study population was 51.83 ±15.93 with a range of 25 - 80 years. Out of 130 patients, 60 patients had positive culture results. Nineteen (31.7%) cases had positive culture for tuberculosis and 41 (63.3%) cases had positive results for other bacteria before intervention that did not change after using 2% lidocaine (p=1). In 70 (53.84%) cases, results were negative before and after use of 2% lidocaine. CONCLUSION: No significant difference was found between culture results before and after the use of lidocaine. Therefore, lidocaine can be used during bronchoscopy to increase patient tolerance.

Rapid detection of Mycobacterium tuberculosis and rifampicin resistance in extrapulmonary tuberculosis and sputum smear-negative pulmonary suspects using Xpert MTB/RIF.

BACKGROUND: Tuberculosis (TB) is a serious public health problem in developing countries such as Pakistan. Rapid diagnosis of TB and detection of drug resistance are very important for timely and appropriate management of multidrug-resistant TB (MDR-TB). OBJECTIVE: The purpose of this study was to determine the diagnostic efficacy of the Xpert MTB/RIF assay for rapid diagnosis of TB and detection of rifampicin (RIF) resistance in extrapulmonary and smear-negative pulmonary TB suspects. METHODS: A total of 98 bronchoalveolar lavage fluid (BALF) and 168 extrapulmonary specimens were processed by Xpert MTB/RIF. Culture results are considered as the gold standard for diagnosis of TB, and drug susceptibility testing for detection of RIF resistance. Diagnostic efficacy was measured in terms of sensitivity, specificity and positive and negative predictive values. RESULTS: The Xpert MTB/RIF assay detected 40 (40.8 %) of 98 BALF of presumptive pulmonary TB and 60 (35.7 %) of 168 extrapulmonary specimens. Sensitivity and specificity of the Xpert MTB/RIF assay for detection of TB was 86 and 88.4 %, respectively. The positive predictive value was 71.5 % while negative predictive value was 95.1 %. CONCLUSION: The Xpert MTB/RIF assay is a rapid and simple technique with high sensitivity and specificity for diagnosing TB and detecting drug resistance in extrapulmonary and smear-negative TB cases.

Liver transplantation is associated with good clinical outcome in patients with active tuberculosis and acute liver failure due to anti-tubercular treatment.

BACKGROUND: Active tuberculosis (TB) is commonly considered a contraindication for liver transplantation (LT). However, in patients with TB who develop acute liver failure (ALF) due to toxicity induced by anti-tubercular treatment (ATT), LT could be the only opportunity for treatment. The aim of this study was to evaluate the feasibility of LT in this scenario. METHODS: We described 2 cases and comprehensively reviewed the literature finding 26 cases of LT performed in patients having a concomitant active TB and liver failure secondary to ATT toxicity. RESULTS: TB was classified as pulmonary in 18/26 (69%), nodal in 3/26 (11%) TB cases, while the remaining 5/26 cases included disseminated, pleural, renal, ovarian, and vertebral TB localization (1 case each). ATT following LT consisted mainly of isoniazid or rifampin (RIF)-sparing regimens and included primarily fluoroquinolones and ethambutol. Rejection episodes and liver toxicity were reported in 19% and 8% of patients respectively. Graft rejection was more frequent among patients treated with RIF-containing regimens (P<.001). Mortality rate was 15% after a median follow up of 12 months. In only one case was death attributed to uncontrolled TB infection. CONCLUSION: Our findings suggest that LT is an effective therapeutic option for patients with active TB developing ALF following ATT and should be considered for patients failing medical treatment.

Acute pulmonary melioidosis presenting with multiple bilateral cavitary lesions in a healthy young adult: an authentic case report from Sri Lanka.

BACKGROUND: Melioidosis is an emerging infectious disease in Sri Lanka. This disease usually develops in a host with an immunocompromised state. Acute pulmonary melioidosis commonly presents as a lobar consolidation with or without pulmonary nodules or abscesses involving the upper lobes of the lungs. CASE PRESENTATION: We report a young healthy female who does not have known risk factors or immunocompromised state, presented with bilateral multiple cavitary lesions involving all three zones of the lungs. She used to involve in home gardening. Her initial relevant microbiological investigations were all negative. The diagnosis of melioidosis was made by broncho-alveolar lavage fluid culture positivity combined with a highly positive antibody titre. She showed dramatic response to intravenous high dose Meropenem. CONCLUSIONS: Melioidosis should be suspected early in patients with acute pulmonary involvement who show poor response to conventional antibiotics, even in the absence of known risk factors for disease. Other than known occupational exposures, household exposures such as home gardening should also be considered as a possible mode of exposure.

[THE UTILITY OF BRONCHOSCOPY IN INTENSIVE CARE UNIT PATIENTS WITH VENTILATOR ASSOCIATED PNEUMONIA].

BACKGROUND: Ventilator associated pneumonia (VAPI is a common complication leading to lengthier hospitalizations and higher mortality. Prompt adequate initial antibiotic coverage is the crucial issue affecting survival. Currently, there is no gold standard diagnostic test. No conclusive data regarding the benefit of bronchoscopy exists in the literature reviewed. AIM: This study aims to evaluate the change of prognosis for patients who developed VAP, following a positive culture from bronchoalveolar lavage (BAL). DESIGN: This is a retrospective cohort study. SETTING: General intensive care unit in a tertiary university healthcare center. PARTICIPANTS: All patients who were admitted to Surgical ICU and developed VAP and who then underwent diagnostic bronchoscopy with BAL between the period 01/02/2007 - 31/02/2011. MEASUREMENTS AND RESULTS: A total of 66 patients who were admitted to the ICU, developed VAP and underwent bronchoscopy while ventilated; 30 patients were excluded. The positive BAL culture group was compared to the negative BAL culture group; there was no difference between demographic and clinical characteristics, mortality rates (for 30 days) or therapy change between the two groups. No complications were reported regarding the bronchoscopy procedure. CONCLUSIONS: Our findings demonstrate that performing y a diagnostic bronchoscopy with BAL does not improve the prognosis of patients with VAP. Furthermore, expanded prospective studies will be needed to conclude regarding its benefit in diagnosis and subsequent rectifying of therapy.

Two case reports of the successful eradication of new isolates of Burkholderia cepacia complex in children with cystic fibrosis.

BACKGROUND: Chronic infection with Burkholderia cepacia complex (BCC) has a detrimental effect on morbidity and mortality for patients with cystic fibrosis (CF). It is therefore logical to attempt to eradicate new isolates however there is a paucity of information to guide treatment. We report the successful eradication of new isolates of BCC in two children with CF. CASE PRESENTATION: Burkholderia cepacia was successfully eradicated in a 14 year old boy with CF and Burkholderia gladioli was successfully eradicated in a six year old girl with CF. In both children two weeks of intravenous (IV) tobramycin, ceftazidime and temocillin were used followed by three months of inhaled tobramycin. Bronchoalveolar lavage samples taken during flexible bronchoscopy were used prior to treatment to exclude spontaneous clearance as well as after treatment to confirm eradication. CONCLUSIONS: New isolates of BCC can be successfully eradicated in children with CF. More research is urgently required in this area to identify the best treatment regimen for BCC eradication.

Lobar distribution in non-cystic fibrosis bronchiectasis predicts bacteriologic pathogen treatment.

Non-cystic fibrosis bronchiectasis (NCFBr) is a major cause of morbidity due to frequent infectious exacerbations. We analyzed the influence of patient age and bronchiectasis location on the bacterial profile of patients with NCFBr. This retrospective cohort study included 339 subjects diagnosed with an infectious exacerbation of NCFBr during the 9-year period between January 2006 and December 2014. Bronchoalveolar lavage (BAL) cultures and high-resolution computed tomography scans (HRCT) were utilized to characterize the location of the bronchiectasis and bacteriologic pathogenic profile. In univariate logistic regression, the frequency of Haemophilus influenzae was higher in patients aged ≤64 years (OR = 0.969, p < 0.0001, 95 % CI 0.954-0.983), whereas the frequency of Pseudomonas aeruginosa (OR = 1.027, p = 0.008, 95 % CI 1.007-1.048) and Enterobacteriaceae (OR = 1.039, p = 0.01, 95 % CI 1.009-1.069) were significantly higher in patients aged >64 years. The lobar distribution of bronchiectasis in the subjects was 25.9 % in the right middle lobe (RML), 20.7 % in the right lower lobe (RLL), 20.4 % in the left lower lobe (LLL), 13.8 % in the lingula, 13 % in the right upper lobe (RUL), and 6.2 % in the left upper lobe (LUL). In the lower lobes, H. influenzae was the dominant species isolated, whereas in the RUL it was P. aeruginosa and in the LUL it was non- tuberculous mycobacterium (NTM). H. influenzae was more prevalent in younger patients, whereas P. aeruginosa, Enterobacteriaceae and NTM predominated in older patients. Different pathogens were associated with different lobar distributions. The RML, RLL and LLL showed a greater tendency to develop bronchiectasis than other lobes.

A Monte Carlo pharmacokinetic/pharmacodynamic simulation to evaluate the efficacy of minocycline, tigecycline, moxifloxacin, and levofloxacin in the treatment of hospital-acquired pneumonia caused by Stenotrophomonas maltophilia.

BACKGROUND: Stenotrophomonas maltophilia has emerged as an important opportunistic pathogen in recent years. Increasing antimicrobial resistance and other contraindications have greatly compromised trimethoprim/sulfamethoxazole (SXT) as the first-line therapeutic option. The objective of this study was to explore other options for treating hospital-acquired pneumonia (HAP) caused by S. maltophilia. METHODS: A total of 102 strains of S. maltophilia were isolated from sputum and bronchoalveolar lavage (BAL) specimens of patients with HAP in our institution. The minimum inhibitory concentration (MIC) values of minocycline, tigecycline, moxifloxacin, and levofloxacin were determined by the agar dilution method. Based on the MICs and the population pharmacokinetic parameters of the investigated antimicrobials, a Monte Carlo simulation was performed to simulate the pharmacokinetic/pharmacodynamic (PK/PD) indices of different regimens. The probability of target attainment (PTA) was estimated at each MIC value and the cumulative fraction of response (CFR) was calculated to evaluate the efficacy of these regimens. RESULTS: The susceptibility rates to minocycline, tigecycline, moxifloxacin, and levofloxacin were 96.1%, 80.4%, 74.5%, and 69.6%, respectively. The estimated CFRs were 96.2% for minocycline 100 mg twice daily; 50.8%/67.1%/75.4% for tigecycline 50/75/100 mg twice daily; 34.3%/48.0%/56.6% for levofloxacin 500/750/1000 mg once daily; and 45.7% for moxifloxacin 400 mg once daily. CONCLUSIONS: The simulation results suggest that minocycline may be a proper choice for treatment of HAP caused by S. maltophilia, while tigecycline, moxifloxacin, and levofloxacin may not be optimal as monotherapy.

Effects of Proanthocyanidins on Adhesion, Growth, and Virulence of Highly Virulent Extraintestinal Pathogenic Escherichia coli Argue for Its Use to Treat Oropharyngeal Colonization and Prevent Ventilator-Associated Pneumonia.

OBJECTIVE: In the context of increasing microbial resistance and limited new antimicrobials, we aimed to study the antimicrobial effects of cranberry proanthocyanidin extracts on Escherichia coli growth, adhesion to epithelial cells, and lung infection. DESIGN: Experimental in vitro and in vivo investigation. SETTING: University research laboratory. SUBJECTS: Seventy-eight 6- to 8-week-old male Balb/C mice. INTERVENTIONS: In vitro, the effect of increasing concentrations of cranberry proanthocyanidin on bacterial growth of different clinical E. coli isolates was evaluated. Ex vivo, adhesion of E. coli to fresh human buccal epithelial cells was measured in the presence or absence of cranberry proanthocyanidin using microscopy. In vivo, lung bacterial count, pulmonary immune response (neutrophil murine chemokine keratinocyte-derived cytokine measurement and polymorphonuclear recruitment in bronchoalveolar lavage fluid), and lethality were evaluated in a pneumonia mouse model with E. coli precultured with or without cranberry proanthocyanidin. E. coli isolates originated from ventilated ICU patients with respiratory tract colonization or ventilator- associated pneumonia. They differed in number of virulence genes. MEASUREMENTS AND MAIN RESULTS: A significant inhibition of bacterial growth was observed with increasing concentration of cranberry proanthocyanidin, affecting both time to maximal growth and maximal growth rate (p<0.0001 for both). The minimal concentration at which this effect occurred was 250 µg/mL. Cranberry proanthocyanidin significantly reduced E. coli adhesion to fresh buccal epithelial cells by up to 80% (p<0.001). Bacterial counts in homogenized lungs and bronchoalveolar lavage fluid were decreased after cranberry proanthocyanidin exposition (p<0.05 and p<0.01, respectively). Cranberry proanthocyanidin also decreased KC concentrations and polymorphonuclear cell recruitment in bronchoalveolar lavage fluid (p<0.05 for both). At identical inoculum, mortality was reduced by more than half in mice inoculated with E. coli exposed to cranberry proanthocyanidin (p<0.01). CONCLUSION: Cranberry proanthocyanidins exhibit potent effects on growth, adhesion, and virulence of oropharyngeal and lung isolates of E. coli, suggesting that cranberry proanthocyanidin could be of clinical interest to reduce oropharyngeal colonization and prevent lung infection.

Ginseng protects against respiratory syncytial virus by modulating multiple immune cells and inhibiting viral replication.

Ginseng has been used in humans for thousands of years but its effects on viral infection have not been well understood. We investigated the effects of red ginseng extract (RGE) on respiratory syncytial virus (RSV) infection using in vitro cell culture and in vivo mouse models. RGE partially protected human epithelial (HEp2) cells from RSV-induced cell death and viral replication. In addition, RGE significantly inhibited the production of RSV-induced pro-inflammatory cytokine (TNF-α) in murine dendritic and macrophage-like cells. More importantly, RGE intranasal pre-treatment prevented loss of mouse body weight after RSV infection. RGE treatment improved lung viral clearance and enhanced the production of interferon (IFN-γ) in bronchoalveolar lavage cells upon RSV infection of mice. Analysis of cellular phenotypes in bronchoalveolar lavage fluids showed that RGE treatment increased the populations of CD8+ T cells and CD11c+ dendritic cells upon RSV infection of mice. Taken together, these results provide evidence that ginseng has protective effects against RSV infection through multiple mechanisms, which include improving cell survival, partial inhibition of viral replication and modulation of cytokine production and types of immune cells migrating into the lung.

Efficacy of AiiM, an N-acylhomoserine lactonase, against Pseudomonas aeruginosa in a mouse model of acute pneumonia.

Quorum sensing (QS) in Pseudomonas aeruginosa regulates the production of many virulence factors and plays an important role in the pathogenesis of P. aeruginosa infection. N-acyl homoserine lactones (AHL) are major QS signal molecules. Recently, a novel AHL-lactonase enzyme, AiiM, has been identified. The aim of this study was to evaluate the effect of AiiM on the virulence of P. aeruginosa in a mouse model of acute pneumonia. We developed a P. aeruginosa PAO1 strain harboring an AiiM-expressing plasmid. The production of several virulence factors by the AiiM-expressing strain was examined. Mice were intratracheally infected with an AiiM-expressing PAO1 strain. Lung histopathology, bacterial burden, and bronchoalveolar lavage (BAL) fluid were assessed at 24 h postinfection. AiiM expression in PAO1 reduced production of AHL-mediated virulence factors and attenuated cytotoxicity against human lung epithelial cells. In a mouse model of acute pneumonia, AiiM expression reduced lung injury and greatly improved the survival rates. The levels of proinflammatory cytokines and myeloperoxidase activity in BAL fluid were significantly lower in mice infected with AiiM-expressing PAO1. Thus, AiiM can strongly attenuate P. aeruginosa virulence in a mammalian model and is a potential candidate for use as a therapeutic agent against P. aeruginosa infection.

Empiric antibiotics pending bronchoalveolar lavage data in patients without pneumonia significantly alters the flora, but not the resistance profile, if a subsequent pneumonia develops.

INTRODUCTION: Ventilator-associated pneumonia (VAP) occurs in up to 25% of mechanically ventilated patients, with an associated mortality up to 50%. Early diagnosis and appropriate empiric antibiotic coverage of VAP are crucial. Given the multitude of noninfectious clinical and radiographic anomalies within trauma patients, microbiology from bronchioalveolar lavage (BAL) is often needed. Empiric antibiotics are administered while awaiting BAL culture data. Little is known about the effects of these empiric antibiotics on patients with negative BAL microbiology if a subsequent VAP occurs during the same hospital course. METHODS: This is a retrospective chart review of intubated trauma patients undergoing BAL for suspected pneumonia over a 3-y period at a Level 1 trauma center. All patients with suspected VAP undergoing a BAL receive empiric antibiotics. If microbiology data are negative at 72 h, all antibiotics are stopped; however, if the BAL returns with ≥10(5) colony-forming units per milliliter, the diagnosis of VAP is confirmed. We divided patients into three groups. Group 1 consisted of patients in whom the initial BAL was positive for VAP. Group 2 consisted of patients with an initial negative BAL, who subsequently developed VAP at a later point in the hospital course. Group 3 consisted of patients with negative BAL who did not develop a subsequent VAP. RESULTS: We obtained 499 BAL specimens in 185 patients over the 3-y period. A total of 14 patients with 23 BAL specimens initially negative for VAP subsequently developed VAP later during the same hospital stay. These patients did not have an increase in the hospital length of stay, intensive care unit days, ventilator days, or mortality compared with those who had a positive culture on the first suspicion of VAP. There was a significant increase in the percentage of Enterobacter (21% versus 8%) and Morganella (8% versus 0%) as the causative organism in these 14 patients when the VAP occurred. Furthermore, the profile of the top two organisms in each group changed. Enterobacter (21%) and Pseudomonas (17%) were the principal organisms in the initial BAL-negative group, whereas the two predominant strains in the initial positive BAL group were methicillin-sensitive Staphylococcus aureus (21%) and Haemophilus influenza (11%). Interestingly, methicillin-resistant S. aureus remained the third most common organism in both groups. Empiric antibiotics also did not seem to induce the growth of multidrug-resistant organisms, and there was no increased rate of secondary infections such as Clostridium difficile. CONCLUSIONS: Ventilator-associated pneumonia remains a significant cause of morbidity and mortality in mechanically ventilated trauma patients. The diagnosis and treatment of VAP continue to be challenging. Once clinically suspected, empiric coverage decreases morbidity and mortality. Our data demonstrate that patients who receive empiric coverage exhibit a significantly different microbiologic profile compared with those who had an initial positive BAL culture. Initial empiric antibiotics in BAL-negative patients were not associated with an increase in multidrug-resistant organisms, hospital, or intensive care unit length of stay, ventilator days, and mortality or secondary infections.

De novo assembly of the Pneumocystis jirovecii genome from a single bronchoalveolar lavage fluid specimen from a patient.

UNLABELLED: Pneumocystis jirovecii is a fungus that causes severe pneumonia in immunocompromised patients. However, its study is hindered by the lack of an in vitro culture method. We report here the genome of P. jirovecii that was obtained from a single bronchoalveolar lavage fluid specimen from a patient. The major challenge was the in silico sorting of the reads from a mixture representing the different organisms of the lung microbiome. This genome lacks virulence factors and most amino acid biosynthesis enzymes and presents reduced GC content and size. Together with epidemiological observations, these features suggest that P. jirovecii is an obligate parasite specialized in the colonization of human lungs, which causes disease only in immune-deficient individuals. This genome sequence will boost research on this deadly pathogen. IMPORTANCE: Pneumocystis pneumonia is a major cause of mortality in patients with impaired immune systems. The availability of the P. jirovecii genome sequence allows new analyses to be performed which open avenues to solve critical issues for this deadly human disease. The most important ones are (i) identification of nutritional supplements for development of culture in vitro, which is still lacking 100 years after discovery of the pathogen; (ii) identification of new targets for development of new drugs, given the paucity of present treatments and emerging resistance; and (iii) identification of targets for development of vaccines.

Bacterial yield from quantitative cultures of bronchoalveolar lavage fluid in patients with pneumonia on antimicrobial therapy.

BACKGROUND/AIMS: Early diagnosis and appropriate antimicrobial choice are crucial when managing pneumonia patients, and quantitative culture of bronchoalveolar lavage (BAL) fluid is considered a useful method for identifying pneumonia pathogens. We evaluated the quantitative yield of BAL fluid bacterial cultures in patients being treated with antimicrobials and attempted to identify factors predictive of positive BAL cultures. METHODS: Patients over 18 years old and whose BAL fluid was subjected to quantitative culture to identify the organism causative of pneumonia between January 1, 2005, and December 31, 2009, were included. We reviewed the results of BAL fluid bacterial cultures and the clinical records, laboratory tests, and radiographic findings of the patients. RESULTS: BAL was performed on 340 patients with pneumonia. A positive BAL culture, defined as isolation of more than 10(4) colony forming units/mL bacteria, was documented in 18 (5.29%) patients. Of these, 9 bacteria isolated from 10 patients were classified as probable pathogens. The most frequently isolated bacteria were methicillin-resistant Staphylococcus aureus, Acinetobacter baumannii, and Pseudomonas aeruginosa. No independent predictive factor for positive BAL cultures was identified. CONCLUSIONS: The yield of quantitative BAL fluid bacterial culture in patients already on antimicrobials was low. Clinicians should be cautious when performing a BAL culture in patients with pneumonia who are already on antimicrobials.

Evaluation of the diagnostic utility of fiberoptic bronchoscopy for smear-negative pulmonary tuberculosis in routine clinical practice.

We evaluated the diagnostic yield of fiberoptic bronchoscopy for the diagnosis of smear-negative pulmonary tuberculosis in patients treated at a referral hospital in Lima, Peru. Of the 611 patients who underwent the procedure, 140 (23%) were diagnosed with tuberculosis based on the analysis of BAL samples. Being young and being male were significantly associated with positive cultures. In addition, 287 patients underwent post-bronchoscopic sputum smear testing for AFB, the results of which increased the diagnostic yield by 22% over that obtained through the analysis of BAL samples alone. We conclude that the analysis of BAL samples and post-bronchoscopic sputum samples provides a high diagnostic yield in smear-negative patients suspected of having pulmonary tuberculosis.