Roles of lytic transglycosylases in biofilm formation and ß-lactam resistance in methicillin-resistant Staphylococcus aureus.

Staphylococcus aureus is responsible for numerous community outbreaks and is one of the most frequent causes of nosocomial infections with significant morbidity and mortality. While the function of lytic transglycosylases (LTs) in relation to cell division, biofilm formation, and antibiotic resistance has been determined for several bacteria, their role in S. aureus remains largely unknown. The only known LTs in S. aureus are immunodominant staphylococcal antigen A (IsaA) and Staphylococcus epidermidis D protein (SceD). Our study demonstrates that, in a strain of methicillin-resistant S. aureus (MRSA), IsaA and SceD contribute differently to biofilm formation and ß-lactam resistance. Deletion of isaA, but not sceD, led to decreased biofilm formation. Additionally, in isaA-deleted strains, ß-lactam resistance was significantly decreased compared to that of wild-type strains. Plasmid-based expression of mecA, a major determinant of ß-lactam resistance in MRSA, in an isaA-deleted strain did not restore ß-lactam resistance, demonstrating that the ß-lactam susceptibility phenotype is exhibited by isaA mutant regardless of the production level of PBP2a. Overall, our results suggest that IsaA is a potential therapeutic target for MRSA infections.

Impact of renal function-based anti-tuberculosis drug dosage adjustment on efficacy and safety outcomes in pulmonary tuberculosis complicated with chronic kidney disease.

BACKGROUND: Dosages of anti-tuberculosis (TB) drugs are recommended to be adjusted according to renal function for patients complicated with chronic kidney disease (CKD). However, the efficacy and safety outcomes of such renal function-based dosage adjustments are not fully elucidated. METHODS: We retrospectively reviewed cases of pulmonary TB susceptible to first-line drugs that were treated at Jikei University Daisan Hospital between 2005 and 2014 with standard regimens based on dosage adjustments according to renal function recommended by international guidelines. Patients were divided into four groups, those with no, mild, moderate or severe CKD. In-hospital TB-related mortality, the rate of sputum culture conversion at 2 months, the frequency of adverse events (AEs), for which at least the temporal discontinuation of the suspect drug was required for patient improvement, and the rate of regimen change due to AEs were assessed. RESULTS: In the 241 enrolled patients (mean age, 64.1 years; 143 men), fourteen patients (5.8%) died due to TB during their hospitalization. The rate of sputum culture conversion at 2 months was 78.0%. The frequency of in-hospital TB-related death and the conversion rate in the groups did not vary significantly according to CKD severity including those in the non-CKD group (P = 0.310 and P = 0.864). Meanwhile, a total of 70 AEs were observed in 60 patients (24.9%) and the difference between the groups in the overall frequency of AEs was almost significant (P = 0.051). Moreover, for the 154 patients with CKD, severe CKD stage was a significant risk factor for regimen change (OR = 5.92, 95% CI = 1.08-32.5, P = 0.041), as were drug-induced hepatitis and cutaneous reaction (OR = 35.6, 95% CI = 8.70-145, P < 0.001; OR = 17.4, 95% CI = 3.16-95.5, P = 0.001; respectively). CONCLUSIONS: Adjusting the dosage of TB treatment for CKD patients according to the guidelines was efficient in terms of similar therapeutic outcome to that of the non-CKD group. However, AEs warrant attention to avoid regimen change in patients with severe CKD, even if the renal function-based dosage adjustment is performed.

Detection of bacterial DNA from central venous catheter removed from patients by next generation sequencing: a preliminary clinical study.

BACKGROUND: Catheter-related infection (CRI) is one of the serious challenges in clinical practice. This preliminary clinical study aimed to examine whether next-generation sequencing (NGS) targeting 16S rDNA, which was PCR-amplified directly from the tip of a central venous catheter (CVC), can be used to identify causative pathogens in CRI, compared to the culture method. METHODS: Hospitalized patients, from whom a CVC had just been removed, were prospectively enrolled and divided into the CRI-suspected and routine removal groups. DNA was extracted from the sonication fluid of CVC specimens derived from patients. For analysis of bacterial composition by NGS, the V3-V4 fragments of bacterial 16S rDNA were PCR-amplified, followed by index PCR and paired-end sequencing on an Illumina MiSeq device. Conventional culture methods were also performed in the CRI-suspected group. RESULTS: Of CVCs collected from the 156 enrolled patients (114 men; mean age 65.6 years), a total of 14 specimens [nine out of 31 patients suspected with CRI and five out of 125 patients without infection symptoms (routine removal group)] were PCR-positive. In five patients with definite CRI, Staphylococcus was the most frequently detected genus by NGS (4/5 specimens), although no pathogens were detected by NGS in the one remaining specimen. The genera identified by NGS were consistent with those from conventional culture tests. There was high agreement between NGS and the culture method in the CRI-suspected group, with sensitivity and specificity values of 80.0% and 76.9%, respectively; meanwhile, the false-positive rate of NGS was as low as 4.0% in the routine removal group. Moreover, several genera, besides the genus identified by culture test, were detected in each patient with definite CRI and surgical site infection (SSI). Additionally, in one patient with SSI, Enterococcaceae were detected not only by NGS but also by abdominal abscess drainage culture. CONCLUSIONS: NGS targeting 16S rDNA was able to analyze the bacterial composition of CVC specimens and detect causative pathogens in patients with CRI and was therefore suggested as a promising diagnostic tool for CRI.

Re-evaluation of the etiology and clinical and radiological features of community-acquired lobar pneumonia in adults.

OBJECTIVE: The aims of this study were to elucidate the frequency and etiology of community-acquired lobar pneumonia (CALP) and the clinical and radiological differences between CALP and tuberculous lobar pneumonia (TLP). PATIENTS AND METHODS: We retrospectively reviewed medical records of patients with community-acquired pneumonia (CAP) (n = 1032) and tuberculosis (n = 1101) admitted to our hospital. RESULTS: Sixty-nine (6.7%) patients with CAP and 23 (2.1%) with pulmonary tuberculosis developed CALP. Legionella species were the most common pathogen (27 patients, 39.1%), followed by Streptococcus pneumoniae (19 patients, 27.5%) and Mycoplasma pneumoniae (18 patients, 26.1%). Symptom duration was longer in the patients with TLP than in those with CALP. On chest radiographs, cavitation in the area of lobar pneumonia and nodular shadows were radiological findings predictive of TLP. High-resolution computed tomography showed cavitation in the area of lobar pneumonia, well-defined centrilobular nodules, and tree-in-bud sign to be the radiological findings predictive of TLP by multivariate logistic regression models. CONCLUSION: Common causes of CALP are Legionella species, S. pneumoniae, and M. pneumoniae. TLP should be considered in patients with lobar pneumonia, particularly in patients with long symptom duration, cavitation, and nodular shadows on chest radiographs, and cavitation, well-defined centrilobular nodules, and tree-in-bud sign on CT.

Pirfenidone inhibits myofibroblast differentiation and lung fibrosis development during insufficient mitophagy.

BACKGROUND: Pirfenidone (PFD) is an anti-fibrotic agent used to treat idiopathic pulmonary fibrosis (IPF), but its precise mechanism of action remains elusive. Accumulation of profibrotic myofibroblasts is a crucial process for fibrotic remodeling in IPF. Recent findings show participation of autophagy/mitophagy, part of the lysosomal degradation machinery, in IPF pathogenesis. Mitophagy has been implicated in myofibroblast differentiation through regulating mitochondrial reactive oxygen species (ROS)-mediated platelet-derived growth factor receptor (PDGFR) activation. In this study, the effect of PFD on autophagy/mitophagy activation in lung fibroblasts (LF) was evaluated, specifically the anti-fibrotic property of PFD for modulation of myofibroblast differentiation during insufficient mitophagy. METHODS: Transforming growth factor-ß (TGF-ß)-induced or ATG5, ATG7, and PARK2 knockdown-mediated myofibroblast differentiation in LF were used for in vitro models. The anti-fibrotic role of PFD was examined in a bleomycin (BLM)-induced lung fibrosis model using PARK2 knockout (KO) mice. RESULTS: We found that PFD induced autophagy/mitophagy activation via enhanced PARK2 expression, which was partly involved in the inhibition of myofibroblast differentiation in the presence of TGF-ß. PFD inhibited the myofibroblast differentiation induced by PARK2 knockdown by reducing mitochondrial ROS and PDGFR-PI3K-Akt activation. BLM-treated PARK2 KO mice demonstrated augmentation of lung fibrosis and oxidative modifications compared to those of BLM-treated wild type mice, which were efficiently attenuated by PFD. CONCLUSIONS: These results suggest that PFD induces PARK2-mediated mitophagy and also inhibits lung fibrosis development in the setting of insufficient mitophagy, which may at least partly explain the anti-fibrotic mechanisms of PFD for IPF treatment.

Detection of pathogens by real-time PCR in adult patients with acute exacerbation of bronchial asthma.

BACKGROUND: Respiratory tract infection is a major cause of acute exacerbation of bronchial asthma (AEBA). Although recent findings suggest that common bacteria are causally associated with AEBA, a comprehensive epidemiologic analysis of infectious pathogens including common/atypical bacteria and viruses in AEBA has not been performed. Accordingly, we attempted to detect pathogens during AEBA by using real-time polymerase chain reaction (PCR) in comparison to conventional methods. METHODS: We prospectively enroled adult patients with AEBA from August 2012 to March 2014. Infectious pathogens collected in nasopharyngeal swab and sputum samples were examined in each patient by conventional methods and real-time PCR, which can detect 6 bacterial and 11 viral pathogens. The causal association of these pathogens with AEBA severity and their frequency of monthly distribution were also examined. RESULTS: Among the 64 enroled patients, infectious pathogens were detected in 49 patients (76.6%) using real-time PCR and in 14 patients (21.9%) using conventional methods (p < 0.001). Real-time PCR detected bacteria in 29 patients (45.3%) and respiratory viruses in 28 patients (43.8%). Haemophilus influenzae was the most frequently detected microorganism (26.6%), followed by rhinovirus (15.6%). Influenza virus was the significant pathogen associated with severe AEBA. Moreover, AEBA occurred most frequently during November to January. CONCLUSIONS: Real-time PCR was more useful than conventional methods to detect infectious pathogens in patients with AEBA. Accurate detection of pathogens with real-time PCR may enable the selection of appropriate anti-bacterial/viral agents as a part of the treatment for AEBA.

Effectiveness of hepatoprotective drugs for anti-tuberculosis drug-induced hepatotoxicity: a retrospective analysis.

BACKGROUND: The effectiveness of hepatoprotective drugs for DIH (drug induced hepatotoxicity) during tuberculosis treatment is not clear. We evaluated the effectiveness of hepatoprotective drugs by comparing the period until the normalization of hepatic enzymes between patients who were prescribed with the hepatoprotective drugs after DIH was occurred and patients who were not prescribed with the hepatoprotective drugs. METHODS: During 2006-2010, 389 patients with active tuberculosis were included in this study. DIH was defined as elevation of peak serum aspartate aminotransferase (AST) and/or alanine aminotransferase (ALT) of more than twice the upper limit of normal (ULN). We divided the patients into the severe (peak serum AST and/or ALT elevation of >5 times the ULN), moderate (peak serum AST and/or ALT elevation of >3 to ≤5 times the ULN), and mild DIH groups (peak serum AST and/or ALT elevation of >2 to ≤3 times the ULN). We compared the average period until the normalization of hepatic enzymes between patient subgroups with and without hepatoprotective drugs (ursodeoxycholic acid: UDCA, stronger neo-minophagen C: SNMC, and glycyrrhizin). RESULTS: In the severe group, there was no significant difference in the average period until the normalization between subgroups with and without hepatoprotective drugs (21.4 ± 10.8 vs 21.5 ± 11.1 days, P = 0.97). In the mild group, the period was longer in the subgroup with hepatoprotective drugs than that without hepatoprotective drugs (15.7 ± 6.2 vs 12.4 ± 7.9 days, P = 0.046). CONCLUSION: Regardless of the severity, hepatoprotective drugs did not shorten the period until the normalization of hepatic enzymes.

Autophagy induction by SIRT6 through attenuation of insulin-like growth factor signaling is involved in the regulation of human bronchial epithelial cell senescence.

Cigarette smoke (CS)-induced cellular senescence has been implicated in the pathogenesis of chronic obstructive pulmonary disease, and SIRT6, a histone deacetylase, antagonizes this senescence, presumably through the attenuation of insulin-like growth factor (IGF)-Akt signaling. Autophagy controls cellular senescence by eliminating damaged cellular components and is negatively regulated by IGF-Akt signaling through the mammalian target of rapamycin (mTOR). SIRT1, a representative sirtuin family, has been demonstrated to activate autophagy, but a role for SIRT6 in autophagy activation has not been shown. Therefore, we sought to investigate the regulatory role for SIRT6 in autophagy activation during CS-induced cellular senescence. SIRT6 expression levels were modulated by cDNA and small interfering RNA transfection in human bronchial epithelial cells (HBECs). Senescence-associated ß-galactosidase staining and Western blotting of p21 were performed to evaluate senescence. We demonstrated that SIRT6 expression levels were decreased in lung homogenates from chronic obstructive pulmonary disease patients, and SIRT6 expression levels correlated significantly with the percentage of forced expiratory volume in 1 s/forced vital capacity. CS extract (CSE) suppressed SIRT6 expression in HBECs. CSE-induced HBEC senescence was inhibited by SIRT6 overexpression, whereas SIRT6 knockdown and mutant SIRT6 (H133Y) without histone deacetylase activity enhanced HBEC senescence. SIRT6 overexpression induced autophagy via attenuation of IGF-Akt-mTOR signaling. Conversely, SIRT6 knockdown and overexpression of a mutant SIRT6 (H133Y) inhibited autophagy. Autophagy inhibition by knockdown of ATG5 and LC3B attenuated the antisenescent effect of SIRT6 overexpression. These results suggest that SIRT6 is involved in CSE-induced HBEC senescence via autophagy regulation, which can be attributed to attenuation of IGF-Akt-mTOR signaling.

Clinical efficacy of anti-glycopeptidolipid-core IgA test for diagnosing Mycobacterium avium complex infection in lung.

BACKGROUND AND OBJECTIVE: It is difficult to verify the bacteriological diagnosis of Mycobacterium avium complex (MAC) infection. The anti-glycopeptidolipid (GPL)-core IgA antibody test was recently developed as a diagnostic method for MAC pulmonary disease. Only a few studies evaluate its clinical efficacy. We conducted retrospective evaluations of clinical characteristics of patients suspected of MAC infection to explore the usefulness of the anti-GPL-core IgA antibody test. METHODS: We retrospectively evaluated 296 patients who were suspected to have MAC infection and underwent anti-GPL-core IgA antibody test between March 2013 and July 2014 in Jikei University hospital. RESULTS: A total of 29 patients were diagnosed with 'definite MAC' based on the American Thoracic Society (ATS) criteria with multiple identifications of MAC. On the other hand, 106 patients were diagnosed with other pulmonary diseases than MAC. The sensitivity and specificity of anti-GPL-core IgA antibody test for MAC diagnosis were 58.6% and 98.1%, respectively. The definite MAC group showed no significant differences in strains, treatment history or number of segments involved. The duration of MAC disease in the positive-antibody group was significantly longer than in the negative-antibody group (P = 0.046). A significant increase in the false-negative rate was observed in patients with malignant disease (P = 0.029). CONCLUSIONS: The anti-GPL-core IgA antibody test demonstrated high sensitivity and specificity for the diagnosis of MAC infection especially in patients without malignant diseases.

Mitochondrial fragmentation in cigarette smoke-induced bronchial epithelial cell senescence.

Mitochondria are dynamic organelles that continuously change their shape through fission and fusion. Disruption of mitochondrial dynamics is involved in disease pathology through excessive reactive oxygen species (ROS) production. Accelerated cellular senescence resulting from cigarette smoke exposure with excessive ROS production has been implicated in the pathogenesis of chronic obstructive pulmonary disease (COPD). Hence, we investigated the involvement of mitochondrial dynamics and ROS production in terms of cigarette smoke extract (CSE)-induced cellular senescence in human bronchial epithelial cells (HBEC). Mitochondrial morphology was examined by electron microscopy and fluorescence microscopy. Senescence-associated ß-galactosidase staining and p21 Western blotting of primary HBEC were performed to evaluate cellular senescence. Mitochondrial-specific superoxide production was measured by MitoSOX staining. Mitochondrial fragmentation was induced by knockdown of mitochondrial fusion proteins (OPA1 or Mitofusins) by small-interfering RNA transfection. N-acetylcysteine and Mito-TEMPO were used as antioxidants. Mitochondria in bronchial epithelial cells were prone to be more fragmented in COPD lung tissues. CSE induced mitochondrial fragmentation and mitochondrial ROS production, which were responsible for acceleration of cellular senescence in HBEC. Mitochondrial fragmentation induced by knockdown of fusion proteins also increased mitochondrial ROS production and percentages of senescent cells. HBEC senescence and mitochondria fragmentation in response to CSE treatment were inhibited in the presence of antioxidants. CSE-induced mitochondrial fragmentation is involved in cellular senescence through the mechanism of mitochondrial ROS production. Hence, disruption of mitochondrial dynamics may be a part of the pathogenic sequence of COPD development.

[A case of Legionella pneumophila pneumonia accompanied by acute respiratory distress syndrome and epilepsy].

A 32-year-old female with epilepsy presented at our hospital with high-grade fever, seizures, and unconsciousness. She was initially treated for aspiration pneumonia with ampicillin/sulbactam. Despite antibiotic therapy, her chest X-ray findings dramatically worsened, showing extension to the bilateral lung field. Her PaO2/FiO2 ratio decreased to 70.6. Rapid progression of hypoxia, unconsciousness, and hyponatremia led to the suspicion of Legionella pneumonia; however, it was difficult to make a definitive diagnosis because she had denied using a whirlpool spa and the initial urinary Legionella antigen test results were negative. Therefore, we repeated the Legionella urinary antigen test, which was positive. On the basis of these results, sputum polymerase chain reaction findings, and the four-fold elevation of paired antibodies, the patient was diagnosed as having Legionella pneumonia accompanied by acute respiratory distress syndrome. We considered administering fluoroquinolone antibiotics, that are recommended for severe Legionella pneumonia, although quinolones have a potential risk for causing convulsions. In this case, we carefully administered ciprofloxacin. The patient recovered consciousness after treatment without any relapse of epileptic seizures. We also administered a corticosteroid for severe pneumonia with the expectation of clinical improvement and to avoid intubation. We emphasize the importance of aggressive workup and empirical therapy for patients with Legionella pneumonia with rapidly worsening symptoms and clinical features such as unconsciousness, epilepsy, and hyponatremia and in whom fluoroquinolone and corticosteroid therapy are effective despite the presence of epilepsy.

Intermittent antibiotic treatment of bacterial biofilms favors the rapid evolution of resistance.

Bacterial antibiotic resistance is a global health concern of increasing importance and intensive study. Although biofilms are a common source of infections in clinical settings, little is known about the development of antibiotic resistance within biofilms. Here, we use experimental evolution to compare selection of resistance mutations in planktonic and biofilm Escherichia coli populations exposed to clinically relevant cycles of lethal treatment with the aminoglycoside amikacin. Consistently, mutations in sbmA, encoding an inner membrane peptide transporter, and fusA, encoding the essential elongation factor G, are rapidly selected in biofilms, but not in planktonic cells. This is due to a combination of enhanced mutation rate, increased adhesion capacity and protective biofilm-associated tolerance. These results show that the biofilm environment favors rapid evolution of resistance and provide new insights into the dynamic evolution of antibiotic resistance in biofilms.

Escherichia coli SPFH Membrane Microdomain Proteins HflKC Contribute to Aminoglycoside and Oxidative Stress Tolerance.

Many eukaryotic membrane-dependent functions are often spatially and temporally regulated by membrane microdomains (FMMs), also known as lipid rafts. These domains are enriched in polyisoprenoid lipids and scaffolding proteins belonging to the stomatin, prohibitin, flotillin, and HflK/C (SPFH) protein superfamily that was also identified in Gram-positive bacteria. In contrast, little is still known about FMMs in Gram-negative bacteria. In Escherichia coli K-12, 4 SPFH proteins, YqiK, QmcA, HflK, and HflC, were shown to localize in discrete polar or lateral inner membrane locations, raising the possibility that E. coli SPFH proteins could contribute to the assembly of inner membrane FMMs and the regulation of cellular processes. Here, we studied the determinant of the localization of QmcA and HflC and showed that FMM-associated cardiolipin lipid biosynthesis is required for their native localization pattern. Using Biolog phenotypic arrays, we showed that a mutant lacking all SPFH genes displayed increased sensitivity to aminoglycosides and oxidative stress that is due to the absence of HflKC. Our study therefore provides further insights into the contribution of SPFH proteins to stress tolerance in E. coli. IMPORTANCE Eukaryotic cells often segregate physiological processes in cholesterol-rich functional membrane microdomains. These domains are also called lipid rafts and contain proteins of the stomatin, prohibitin, flotillin, and HflK/C (SPFH) superfamily, which are also present in prokaryotes but have been mostly studied in Gram-positive bacteria. Here, we showed that the cell localization of the SPFH proteins QmcA and HflKC in the Gram-negative bacterium E. coli is altered in the absence of cardiolipin lipid synthesis. This suggests that cardiolipins contribute to E. coli membrane microdomain assembly. Using a broad phenotypic analysis, we also showed that HflKC contribute to E. coli tolerance to aminoglycosides and oxidative stress. Our study, therefore, provides new insights into the cellular processes associated with SPFH proteins in E. coli.

[A case of descending necrotizing mediastinitis caused by infection with Streptococcus agalactiae in a patient with diabetes mellitus].

We report a case with an atypical presentation of descending necrotizing mediastinitis (DNM). A 47-year-old woman with a medical history of untreated type 2 diabetes mellitus and influenza type A virus infection 2 weeks prior to admission was referred to our hospital complaining of right cervical pain and right upper limb swelling. A chest enhanced computed tomographic (CT) scan showed a ring-enhanced mass-like shadow extending from the right sternomastoid muscle down to the right upper mediastinum, compressing the right subclavicular vein. We diagnosed the patient as having DNM based on a physical examination and the CT findings. Because the abscess extended from deep in the neck to the upper mediastinum and right upper pleural space, emergent abscess debridement and drainage was required. After hospitalization, antibiotics (Ampicillin/Sulbactam 12 g/day) were also administered based on Gram-stain findings from the drainage fluid, which showed Gram-positive cocci resembling a string of beads. A culture of the drainage fluid identified Streptococcus agalactiae. Aggressive abscess drainage and early antibiotic therapy resulted in a favorable response. She was discharged without complications on the 33rd hospital day. DNM is well known as a rare but lethal disease. In this case, the presence of diabetes mellitus and post-influenza infection might have been risk factors for a serious S. agalactiae infection. Early aggressive therapy and adequate drainage are recommended for patients with DNM.

Small-Molecule-Induced Activation of Cellular Respiration Inhibits Biofilm Formation and Triggers Metabolic Remodeling in Staphylococcus aureus.

Staphylococcus aureus, a major pathogen of community-acquired and nosocomial-associated infections, forms biofilms consisting of extracellular matrix-embedded cell aggregates. S. aureus biofilm formation on implanted medical devices can cause local and systemic infections due to the dispersion of cells from the biofilms. Usually, conventional antibiotic treatments are not effective against biofilm-related infections, and there is no effective treatment other than removing the contaminated devices. Therefore, the development of new therapeutic agents to combat biofilm-related infections is urgently needed. We conducted high-throughput screening of S. aureus biofilm inhibitors and obtained a small compound, JBD1. JBD1 strongly inhibits biofilm formation of S. aureus, including methicillin-resistant strains. In addition, JBD1 activated the respiratory activity of S. aureus cells and increased the sensitivity to aminoglycosides. Furthermore, it was shown that the metabolic profile of S. aureus was significantly altered in the presence of JBD1 and that metabolic remodeling was induced. Surprisingly, these JBD1-induced phenotypes were blocked by adding an excess amount of the electron carrier menaquinone to suppress respiratory activation. These results indicate that JBD1 induces biofilm inhibition and metabolic remodeling through respiratory activation. This study demonstrates that compounds that enhance the respiratory activity of S. aureus may be potential leads in the development of therapeutic agents for chronic S. aureus-biofilm-related infections. IMPORTANCE Chronic infections caused by Staphylococcus aureus are characterized by biofilm formation, suggesting that methods to control biofilm formation may be of therapeutic value. The small compound JBD1 showed biofilm inhibitory activity and increased sensitivity to aminoglycosides and respiratory activity of S. aureus. Additionally, transcriptomic and metabolomic analyses demonstrated that JBD1 induced metabolic remodeling. All JBD1-induced phenotypes were suppressed by the extracellular addition of an excess amount of menaquinone, indicating that JBD1-mediated respiratory stimulation inhibits biofilm formation and triggers metabolic remodeling in S. aureus. These findings suggest a strategy for developing new therapeutic agents for chronic S. aureus infections.

[Nemaline myopathy detected with respiratory failure and right ventricular heart failure].

We describe the case of a 40-year-old woman who was admitted for dyspnea and pitting edema of the lower extremities. Severe type II respiratory failure and right ventricular heart failure were present. Non-invasive positive pressure ventilation (NIPPV) improved the symptoms and blood gas values. Since the results of respiratory function tests and computed tomography indicated neuromuscular disease, muscle biopsy was performed and nemaline myopathy was diagnosed. NIPPV was necessary due to severe hypoxia and hypercapnia caused by severe hypoventilation during sleep; however, daytime NIPPV was stopped within a few days, and the patient was discharged with instructions to continue NIPPV at night only. Since discharge, she has been followed-up on an outpatient basis for 8 years. Adult-onset nemaline myopathy with respiratory failure and right ventricular heart failure as presenting features is rare, and NIPPV can be useful in such cases.

[Severe complications and their outcomes in 65 patients with Legionella pneumonia].

The aim of the current study was to investigate the lethal complications of Legionella pneumonia. Severe complications and their outcomes in 65 patients with Legionella pneumonia were studied. All patients who eventually had a fatal outcome or who had severe complications received antimicrobial agents active against Legionella on the admission day. Many patients in the severe complication category had multiple severe complications. Six deaths occurred (mortality rate 9.2%), 4 of which were due to septic shock/multiple organ dysfunction syndrome (MODS) (2 patients) or interstitial pneumonia/pulmonary fibrosis after Legionella pneumonia (2 patients), whereas the other 2 deaths were due to causes unrelated to Legionella pneumonia. Mortality rates for each severe complication were as follows: acute respiratory distress syndrome 27.3% (3 of 11); renal failure 33.3% (2 of 6); disseminated intravascular coagulation 33.3% (2 of 6); severe sepsis 0% (0 of 1); septic shock/MODS 66.7% (2 of 3); interstitial pneumonia/pulmonary fibrosis 50% (2 of 4). Despite prompt diagnosis and appropriate treatment with antimicrobial agents active against Legionella, the lethal complications of Legionella pneumonia are septic shock/MODS and interstitial pneumonia/pulmonary fibrosis.

[Primary ciliary dyskinesia. A case report and comparison with 4 previous cases].

We encountered a 59-year-old man, whose chief complaints were sputum and dyspnea on effort. He had suffered from sinusitis since childhood, and chest computed tomography showed bronchiectasis. Electron microscopic examination of bronchial mucosa biopsied by bronchoscopy showed defect of the inner dynein arm in most of his cilia. We diagnosed primary ciliary dyskinesia. Seminal analysis showed no abnormalities, and the etiology of infertility remains unclear. The present case is the fifth case treated at our hospital. In this paper, we compared this case with 4 cases (2 cases of Kartagener's syndrome and 2 cases of primary ciliary dyskinesia without situs invertus) of our hospital, and findings of previous reports. Primary ciliary dyskinesia should be included in the differential diagnosis even in cases of mild bronchiectasis or normal mobility of sperm. Primary ciliary dyskinesia has more variety in radiological and clinical findings than has been recognized.

[Mucoid impaction of the bronchi caused by Schizophyllum commune which developed after discontinuation of itraconazole administration].

We report the case of a 75-year-old woman with mucoid impaction of the bronchi (MIB) due to Schizophyllum commune who improved with itraconazole (ITCZ) administration and relapsed after discontinuation of the drug. She improved again after readministration of ITCZ, and MIB has not recurred. This patient was not suffering from asthma and has been well without steroid administration. Reports of respiratory disorders due to S. commune have been increasing, and cases of allergic bronchopulmonary mycosis (ABPM), fungus ball, lung abscess, and pneumonia have been reported. Including this report, 12 cases of ABPM and MIB due to S. commune have been reported by Japanese authors. Treatment in these 12 cases included anti-fungal agent in 6, single steroid therapy in 3, combination therapy in 2, and bronchial toilet in 1 case. S. commune is not well recognized; however, one should suspect this fungus to be the causative pathogen when Aspergillus species are not detected or anti-Aspergillus antibody is negative.