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This study aimed to investigate the bacterial characteristics of pneumococcal isolates obtained from a tertiary care hospital in Japan. We analyzed the antimicrobial susceptibility, possession of macrolide resistance genes, pneumococcal serogroup/serotype, and sequence type (ST) of pneumococcal isolates from patients aged 15 years or older between 2011 and 2020 at Nagasaki University Hospital. Of the 73 isolates analyzed, 86.3% showed resistance to macrolides, and 28.8%, 46.6%, and 11.0% harbored mefA , ermB , and both, respectively. Of the isolates possessing ermB , 97.6% showed high levels of macrolide resistance [minimal inhibitory concentration (MIC) range, > 16 µg/mL]. Solithromycin (MIC range, 0.03-0.25 µg/mL), regardless of the presence of macrolide resistance genes, and lascufloxacin (MIC range, 0.06-0.5 µg/mL) showed potent in vitro activity against pneumococci. Serotype 19A was the most prevalent (six isolates), followed by serotypes 10A, 15A, and 15B/C (five isolates each). Four serotypes (11A, 19A, 22F, and 23B) and five STs (36, 99, 433, 558, and 3111) were significantly correlated with the presence of macrolide resistance genes. All four isolates with serotype 11A/ST99 and three isolates with serotype 19A/ST3111 harbored both mefA and ermB . No macrolide resistance genes were detected in either of the two isolates with serotype 22F/ST433, while all ten isolates with serogroup 15 (serotypes 15A and 15B/C, five isolates each) possessed ermB alone. Our study revealed the bacterial characteristics of the pneumococcal isolates obtained from our hospital. In vitro activity of solithromycin and lascufloxacin against these isolates was confirmed., Competing Interests: Solithromycin and lascufloxacin were provided by FUJIFILM Toyama Chemical Co., Ltd. and Kyorin Pharmaceutical Co., Ltd., respectively., (Copyright © 2024 Nakao, Kosai, Akamatsu, Ota, Mitsumoto-Kaseida, Hasegawa, Izumikawa, Mukae and Yanagihara.)

Background: Nursing- and healthcare-associated pneumonia (NHCAP) constitutes most of the pneumonia in elderly patients including aspiration pneumonia in Japan. Lascufloxacin (LSFX) possesses broad antibacterial activity against respiratory pathogens, such as Streptococcus spp. And anaerobes inside the oral cavity. However, the efficacy and safety of LSFX in NHCAP treatment remains unknown. We aimed to evaluate the efficacy and safety of LSFX tablets in the treatment of patients with NHCAP., Methods: In this single-arm, open-label, uncontrolled study, LSFX was administered to patients with NHCAP at 24 facilities. The study participants were orally administered 75 mg LSFX once daily for 7 days. The primary endpoint was the clinical efficacy at the time of test of cure (TOC). The secondary endpoints included clinical efficacy at the time of end of treatment (EOT), early clinical efficacy, microbiological efficacy, and safety analysis., Result: During the study period, 75 patients provided written informed consent to participate and were included. Finally, 56 and 71 patients were eligible for clinical efficacy and safety analyses, respectively. The median age of the patients was significantly high at 86 years. All patients were classified as having moderate disease severity using the A-DROP scoring system. LSFX tablets demonstrated high efficacy rates of 78.6 % at TOC and 89.3 % at EOT. The risk factors for resistant bacteria or aspiration pneumonia did not affect clinical efficacy. No severe adverse events associated with the study drugs were observed., Conclusion: Oral LSFX is an acceptable treatment option for moderate NHCAP in elderly patients who can take oral medications., Competing Interests: Declaration of competing interest Hiroshi Mukae received lecture honoraria and research grants from KYORIN Pharmaceutical Co., Ltd. Outside of the submitted work., (Copyright © 2024 Japanese Society of Chemotherapy, Japanese Association for Infectious Diseases, and Japanese Society for Infection Prevention and Control. Published by Elsevier Ltd. All rights reserved.)

Objectives: This study evaluated the serotype distribution and antimicrobial susceptibility of Streptococcus pneumoniae isolates from adults (aged ≥20 years) with invasive pneumococcal disease (IPD) in Japan., Methods: This prospective observational study was conducted in 49 participating Japanese hospitals. S. pneumoniae isolates were serotyped and tested for antimicrobial susceptibility at a central laboratory. Information regarding patient characteristics, underlying disease, IPD clinical syndromes, and treatment was collected through medical chart review., Results: The final analysis included 177 patients enrolled from 45 hospitals between September 2016 and April 2018 (bacteraemic pneumonia, 110; bacteraemia without identified focus, 29; meningitis, 19). Most patients (70.1%) were aged ≥65 years and most had underlying disease (79.1%). The proportion of isolates from serotypes contained in the pneumococcal polysaccharide vaccine (PPV) 23 was 61.0%, while those in the pneumococcal conjugate vaccine (PCV) 7 and PCV13 were 2.8% and 28.2%, respectively. Non-vaccine serotypes accounted for 37.9% of all isolates and 50.8% of isolates from immunosuppressed patients. Serotype 12F was the most common vaccine serotype, followed by serotype 3., Conclusions: The continued disease burden of IPD in adults in Japan warrants improved vaccination rates and development of next-generation vaccines that include serotypes not currently covered., Clinical Trial Registration: Clinical trial summary registration number 160,822,918,146; JapicCTI-163352., (Copyright © 2020 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Oral treatment for elderly outpatients with pneumonia is becoming increasingly important in this super-aged society from the perspective of cost-effectiveness and limited hospital capacities. We evaluated the efficacy and safety of two oral respiratory quinolones, sitafloxacin and garenoxacin, in elderly patients with pneumonia. This randomized, multicenter, open-label trial was conducted among patients aged ≥65 years with clinically and radiographically confirmed pneumonia in Japan. Patients were randomly assigned (1:1) to receive either sitafloxacin (100 mg/day) or garenoxacin (400 mg/day) for 3-10 days. The primary efficacy endpoint was the clinical cure rate at 5-10 days after the end of treatment. From December 2013 to November 2017, we enrolled 120 patients at 11 hospitals and randomly assigned 59 patients to the sitafloxacin group (1 patient withdrew) and 61 patients to the garenoxacin group. These included 30 patients with nursing and healthcare-associated pneumonia (NHCAP) (18 receiving sitafloxacin, 12 receiving garenoxacin) and 37 patients with aspiration pneumonia (16 receiving sitafloxacin, 21 receiving garenoxacin). The clinical cure rates in the sitafloxacin and garenoxacin groups were 88.5% (95% confidence interval: 76.6-95.6) and 88.9% (95% confidence interval: 77.4-95.8), respectively. No significant differences were observed in the incidence rates of drug-related adverse events between the sitafloxacin (20.7%; 12/58 patients) and garenoxacin (27.9%; 17/61 patients) groups. The most common adverse event was hepatic dysfunction, which occurred in seven patients in each group. We conclude that sitafloxacin and garenoxacin are comparably effective and safe for the treatment of pneumonia, including NHCAP and aspiration pneumonia, in elderly patients., (Copyright © 2019 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.)

Aim: Pneumonia in older adults is increasingly recognized as a healthcare issue in countries with an aging population. Long-term macrolide therapy reduces exacerbations of chronic respiratory diseases, but its effects on the prevention of pneumonia have not been determined., Methods: We carried out a randomized, controlled trial to test the effect of long-term clarithromycin therapy on the prevention of pneumonia among older adults. People aged ≥65 years who had recovered from pneumonia within the previous 3 months were recruited and randomly allocated to a long-term, low-dose clarithromycin (CAM) therapy group (n = 13) or a control group (n = 15)., Results: Both groups were followed up until recurrence of pneumonia. The median follow-up period was 251 days (95% CI 171-330) in the CAM group and 132 days (95% CI 67-196) in the control group (P = 0.627). The recurrence rate of pneumonia was two out of 13 (15%) in the CAM group and five out of 15 (33%) in the control group (P = 0.268). The median time to recurrence of pneumonia was 315 days (95% CI 249-382) in the CAM group and 260 days (95% CI 184-335) in the control group (P = 0.260). None of the differences between groups were statistically significant., Conclusions: No statistically significant suppressive effects of long-term, low-dose macrolide therapy on the development of pneumonia among older people were found in this small sample. A large-scale, randomized, controlled study is required. Geriatr Gerontol Int 2019; 19: 1006-1009., (© 2019 Japan Geriatrics Society.)

The nationwide surveillance on antimicrobial susceptibility of bacterial respiratory pathogens from the patients in Japan was conducted by Japanese Society of Chemotherapy, the Japanese Association for Infectious Diseases, and the Japanese Society for Clinical Microbiology in 2014. The isolates were collected from clinical specimens obtained from well-diagnosed adult patients with respiratory tract infections during the period between January 2014 and April 2015 by three societies. Antimicrobial susceptibility testing was conducted at the central reference laboratory according to the method recommended by Clinical Laboratory Standards Institute. Susceptibility testing was evaluated in 1534 strains (335 Staphylococcus aureus, 264 Streptococcus pneumoniae, 29 Streptococcus pyogenes, 281 Haemophilus influenzae, 164 Moraxella catarrhalis, 207 Klebsiella pneumoniae, and 254 Pseudomonas aeruginosa). Ratio of methicillin-resistant S. aureus was 43.6%, and those of penicillin-susceptible S. pneumoniae was 100%. Among H. influenzae, 8.2% of them were found to be β-lactamase-producing ampicillin-resistant strains, and 49.1% to be β-lactamase-non-producing ampicillin-resistant strains. Extended spectrum β-lactamase-producing K. pneumoniae and multi-drug resistant P. aeruginosa with metallo β-lactamase were 9.2% and 0.4%, respectively., (Copyright © 2019 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.)

Oral antibiotic therapy for patients with acute exacerbations of chronic obstructive pulmonary disease (COPD) usually involves an aminopenicillin with clavulanic acid, a macrolide, or a quinolone. To date, however, the clinical efficacy and safety of the oral cephalosporin cefditoren pivoxil has not been evaluated in Japanese patients with acute exacerbations of COPD. We conducted a prospective, multicenter, single arm, interventional study from January 2013 to March 2017 to determine the efficacy and safety of oral administration of 200 mg cefditoren pivoxil three times daily for 7 days in a cohort of 29 eligible patients from 15 hospitals. The mean age (SD) of participants was 73.1 (8.1) years and 28 had a smoking history (the mean [SD] of smoking index, 1426.7 [931.7]). The primary efficacy endpoint was clinical response (cure rate) at test of cure, which was set at 5-10 days after treatment ceased. Of the 23 patients finally analyzed, cure was achieved in 15 (65.2%), while 8 (34.8%) remained uncured. Previous experience of acute exacerbations significantly affected the cure rate: none of the three patients who had at least two prior exacerbations were cured, while 15 of the 20 patients with one or fewer prior exacerbations were cured (p = 0.032). The microbiological eradication rate was 88.9% at test of cure. During treatment, mild pneumonia was reported as an adverse event in one patient (3.4%) but resolved within 10 days of onset. We conclude that cefditoren pivoxil represents a viable alternative for antibiotic therapy in patients with few prior exacerbations., (Copyright © 2019 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.)

This study investigated the molecular and phenotypic characteristics of carbapenemase-producing Klebsiella pneumoniae, and identified the risk factors underlying its acquisition. We evaluated K. pneumoniae isolated in Nagasaki University Hospital between January 2009 and June 2015. The presence of carbapenemase genes and plasmid characteristics were investigated. We performed multilocus sequence typing (MLST), and generated a dendrogram based on the results of pulsed-field gel electrophoresis (PFGE) for carbapenemase-producing strains. We also performed a case-control study of patients. Of the 88 K. pneumoniae strains that showed minimum inhibitory concentration ≥1 μg/mL for imipenem and/or meropenem, and that were available from our bacterial collection, 18 had the IMP-type carbapenemase gene, all of which were IMP-1 according to sequencing analysis. Strains included seven different sequence types (STs), of which the most common was ST1471. A dendrogram showed the significant similarity of some strains with relationships in PFGE patterns, STs, and the wards in which they were isolated. Plasmid incompatibility group was similar among the IMP-1 producers. Regarding risk factors, multivariate analysis showed that liver disease and previous uses of carbapenems and anti-fungal drugs were significant factors for the acquisition of IMP-1-producing strains. Our results demonstrate that IMP-1 is a major carbapenemase produced by K. pneumoniae. The PFGE results indicated the possibility of transmission in the hospital. The identified risk factors should be considered for appropriate antibiotic therapy and infection-control measures., (Copyright © 2018 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.)

Background: Parvimonas micra, a Gram-positive anaerobic coccus, is a rare pathogen for psoas abscess. We describe a case of a patient with iliopsoas abscess caused by P. micra., Case Presentation: An 81-year-old Asian man presented to our department with complaints of fever since the preceding day. Abdominal computed tomography revealed the presence of a low-density mass in the right iliopsoas muscle indicative of a psoas abscess. Computed tomography-guided percutaneous drainage of the psoas abscess was performed. Results of organism cultures of the abscess and blood were positive for P. micra. However, our patient had no known primary focus of infection. On the basis of these findings, a primary psoas abscess caused by P. micra was diagnosed, and treatment with ampicillin/sulbactam 1.5 g, administered intravenously every 8 h, was initiated. By day 7, the patient's white blood cell count normalized. By day 20, his C-reactive protein level was decreased to 0.35 mg/dl., Conclusion: Iliopsoas abscesses caused by anaerobic bacteria are relatively rare, and iliopsoas abscesses caused by P. micra are especially rare. Our patient's case revealed that P. micra can cause iliopsoas abscess. Therefore, clinicians should be aware of the possibility that P. micra may cause iliopsoas abscess.

The nationwide surveillance on antimicrobial susceptibility of bacterial respiratory pathogens from the patients in Japan was conducted by Japanese Society of Chemotherapy, Japanese association for infectious diseases and Japanese society for Clinical Microbiology in 2012. The isolates were collected from clinical specimens obtained from well-diagnosed adult patients with respiratory tract infections during the period between January and December in 2012 by three societies. Antimicrobial susceptibility testing was conducted at the central reference laboratory according to the method recommended by Clinical Laboratory Standard Institutes. Susceptibility testing was evaluated in 1236 strains (232 Staphylococcus aureus, 225 Streptococcus pneumoniae, 16 Streptococcus pyogenes, 231 Haemophilus influenzae, 147 Moraxella catarrhalis, 167 Klebsiella pneumoniae and 218 Pseudomonas aeruginosa). Ratio of methicillin-resistant S. aureus was 51.3%, and those of penicillin-intermediate S. pneumoniae was 0.4%. Among H. influenzae, 5.6% of them were found to be β-lactamase-producing ampicillin-resistant strains, and 37.2% to be β-lactamase-non-producing ampicillin-resistant strains. Extended spectrum β-lactamase-producing K. pneumoniae and multi-drug resistant P. aeruginosa with metallo β-lactamase were 4.2% and 3.2%, respectively. Continuous national surveillance is important to determine the actual situation of the resistance shown by bacterial respiratory pathogens to antimicrobial agents., (Copyright © 2017 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.)

The innate immune system plays an important role in early immunity against respiratory tract infection. Although airway epithelial cells produce mucus to eliminate pathogens and irritants, hypersecretion of mucus is harmful for the host as it may cause airway obstruction and inhibit influx of antimicrobial agents. It has been reported that several antimicrobial agents have an immunomodulatory effect in vitro and in vivo, but little is known about whether tedizolid, a novel oxazolidinone, can modulate immune responses. In this study, we evaluated whether tedizolid can suppress MUC5AC production in human airway epithelial cells stimulated by methicillin-resistant Staphylococcus aureus (MRSA). Compared with the control, tedizolid significantly inhibited MUC5AC protein production and mRNA overexpression at concentrations of both 2 and 10 μg/mL (representative of trough and peak concentrations in human epithelial lining fluid). Among the mitogen-activated protein kinase inhibitors tested, only extracellular signal-regulated protein kinase 1/2 (ERK1/2) phosphorylation was inhibited by tedizolid as indicated by western blot analysis. These results indicate that tedizolid inhibits the overproduction of MUC5AC protein by inhibiting phosphorylation of ERK1/2. This study revealed that tedizolid suppresses excessive mucin production in human airway epithelial cells. The immunomodulatory effect of tedizolid may improve outcomes in patients with severe respiratory infectious diseases caused by MRSA., (Copyright © 2017 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.)

Enterococci have become increasingly important pathogens for nosocomial infection (e.g. bacteremia, intra-abdominal infection, endocarditis, etc.), related to their intrinsic resistance to many antibiotics. Although the in vitro susceptibility of daptomycin (DAP) against Enterococci is well established, the Food and Drug Administration has only approved its use for complicated skin and skin structure infections induced by Enterococcus faecalis. In this study we evaluated the potential therapeutic application of DAP in a murine model of enterococcal experimental peritonitis. Mice were injected intraperitoneally with 4 × 10 10 colony-forming units of Enterococcus faecium. DAP alone, DAP combined with ampicillin, vancomycin, or linezolid were administered 2 h after enterococcal inoculation and examined the survival, viable bacteria counts, the level of KC/CXCL1 in the peritoneal fluid. The viable bacteria counts in the peritoneal fluid of the DAP- or DAP plus ampicillin-treated groups were decreased significantly compared to those of the vancomycin- and linezolid-treated groups (P < 0.05) at 6 and 12 h after the inoculation of Enterococcus. The level of neutrophil chemoattractants KC in the peritoneal fluid at 12 h after enterococcal inoculation was significantly decreased in the DAP plus ampicillin-treated group (P < 0.05). In addition DAP showed the inhibitory effect of enterococcal biofilm formation dose-dependently by a microtiter biofilm assay. These results indicate that DAP, particularly with β-lactams, is a possible alternative agent to treat severe enterococcal infection such as peritonitis., (Copyright © 2016 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.)

OP0595 (RG6080) is a novel diazabicyclooctane that inhibits class A and C serine beta-lactamases. Although the combination of OP0595 and cefepime (FEP) showed good in vitro activity against extended-spectrum-beta-lactamase (ESBL)-producing pathogens, the effect of the combination therapy against severe infections, such as pneumonia or bacteremia, remains unknown in vivo In this study, we investigated the efficacy and pharmacokinetics of the combination therapy of OP0595 and FEP in a mouse model of pneumonia caused by Klebsiella pneumoniae harboring SHV- and CTX-M-9-type ESBLs. The infected BALB/c mice were intraperitoneally administered saline (control), 100 mg/kg of body weight of FEP, 20 mg/kg of OP0595, or both FEP and OP0595, twice a day. The MIC of FEP against the bacteria was 8 mg/liter and markedly improved to 0.06 mg/liter with the addition of 0.5 mg/ml of OP0595. In the survival study, the combination of FEP and OP0595 significantly improved the survival rate compared with that reported with either OP0595 or FEP alone ( P < 0.001). The number of bacteria in the lungs and blood significantly decreased in the combination therapy group compared to that reported for the monotherapy groups ( P < 0.001). In addition, the in vivo effect depended on the dose of FEP. However, pharmacokinetic analysis revealed that the percentage of time above MIC remained constant when increasing the dose of FEP in combination with 20 mg/kg of OP0595. The results of our study demonstrated the in vivo effectiveness of the combination of OP0595 and FEP., (Copyright © 2017 American Society for Microbiology.)

Background: Arbekacin is an aminoglycoside that shows strong antimicrobial activity against Gram-positive bacteria, including MRSA, as well as Pseudomonas aeruginosa . The therapeutic effectiveness of arbekacin is directly related to C max at the infection site. To maximize drug delivery to the respiratory tract and minimize the systemic toxicity, arbekacin optimized for inhalation, ME1100, is under development. In this study, we investigated the efficacy and pharmacokinetics of ME1100 in a murine model of ventilator-associated pneumonia caused by P. aeruginosa by using a customized investigational nebulizer system., Methods: The mice were treated for 5 min, once daily, with placebo, 3, 10 or 30 mg/mL ME1100 or 30 mg/mL amikacin., Results: In the survival study, the survival rate was significantly improved in the 10 and 30 mg/mL ME1100 treatment groups compared with that in the placebo group. The number of bacteria in the lungs was significantly lower in the 30 mg/mL ME1100 treatment group at 6 h after the initial treatment, compared with all other groups. In the pharmacokinetic study, the C max in the 30 mg/mL ME1100 treatment group in the epithelial lining fluid (ELF) and plasma was 31.1 and 1.2 mg/L, respectively. Furthermore, we compared the efficacy of ME1100 with that of amikacin. Although there were no significant differences in ELF and plasma concentrations between 30 mg/mL of ME1100 and 30 mg/mL of amikacin, ME1100 significantly improved the survival rate compared with amikacin., Conclusions: The results of our study demonstrated the in vivo effectiveness of ME1100 and its superiority to amikacin., (© The Author 2016. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

High-dose meropenem (MEPM; 6 g/day) has been approved as a treatment for purulent meningitis; however, little is known regarding its in vivo efficacy in refractory lower respiratory tract infections. The purpose of this study was to evaluate the efficacy of MEPM at 6 g/day in a murine model of severe pneumonia caused by MEPM-resistant Pseudomonas aeruginosa Experimental pneumonia induced by MEPM-resistant P. aeruginosa was treated with normal-dose MEPM (150 mg/kg of body weight, simulating a 3-g/day regimen in humans) or high-dose MEPM (500 mg/kg, simulating a 6-g/day regimen in humans). Mice treated with high-dose MEPM showed significantly restored survival relative to that of untreated mice and tended to show a survival rate higher than that of mice treated with normal-dose MEPM. The viable bacterial counts (of two clinical isolates) in the lungs decreased significantly in mice treated with high-dose MEPM from those for untreated mice (P < 0.001) or mice treated with normal-dose MEPM (P, <0.01 and <0.05). The number of inflammatory cells in the bronchoalveolar lavage fluid (BALF) was also significantly lower in mice treated with high-dose MEPM than in untreated mice. The free MEPM concentration in the epithelial lining fluid (ELF) exceeded 16 μg/ml for 85 min in mice treated with high-dose MEPM, but not for mice treated with normal-dose MEPM. Our results demonstrate that high-dose MEPM (6 g/day) might provide better protection against pneumonia caused by MEPM-resistant strains of P. aeruginosa than the dose normally administered (less than 3 g/day)., (Copyright © 2016 American Society for Microbiology.)

Tedizolid (TZD) is a second-generation oxazolidinone and demonstrates potent in-vitro activity against multidrug-resistant Gram-positive bacteria. Phase III studies in patients with acute bacterial skin and skin structure infections (ABSSSI) have demonstrated the non-inferiority of TZD to linezolid (LZD). However, there are only a few studies that show the effect of TZD in pulmonary infections. In this study, we investigated the effect of TZD in a murine model of hematogenous pulmonary infection caused by methicillin-resistant Staphylococcus aureus (MRSA). The mice were treated either twice daily with saline (control), 25mg/kg of vancomycin (low-VAN), 110mg/kg of vancomycin (high-VAN), 120mg/kg of LZD or once daily with 20mg/kg of TZD. As compared to the control, the low- and high-VAN treatment groups, LZD and TZD significantly improved the survival rate, reduced the bacterial count in the lungs. Furthermore, TZD decreased the area of central bacterial colony zone (CBCZ) at 36h post-inoculation, compared with the control. In addition, we investigated the immunomodulatory effect of TZD by evaluating the plasma concentrations of the inflammatory cytokines. Although there were no significant differences in the bacterial count in the lungs amongst the drugs at 26h post-inoculation, TZD and LZD significantly improved the plasma concentrations of TNF-alpha, IL-6 and MIP-2, in comparison with the control. In this study, both TZD and LZD demonstrated antimicrobial and immunomodulatory efficacy in a murine model of hematogenous pulmonary infection caused by MRSA., (Copyright © 2016 Elsevier GmbH. All rights reserved.)

The balance of "Host-Pathogen-Antimicrobials" is crucial for the establishment of infectious diseases. Recently the ineffective cases, even though the appropriate antibiotics use, have been increasing since the several ineludible problems are rising, such as varied patient's background and the epidemic of the drug resistant pathogens, etc. Despite of the medical progression and the development of novel antimicrobials, the mortality of pneumonia has increased gradually and been the third cause of death in Japan. The conventional treatment depended on only bactericidal effect of antimicrobials faces a limit and the alternative strategies are required to overcome the current situation. This review addresses the potency of non-antibiotic antimicrobial agents as an alternative therapeutic strategy, especially focused on the activation of the innate host immunity induced by the macrolides and toll-like receptor agonist.

Background: Pneumonia is now the third leading cause of death in Japan, and the number of patients with pneumonia is expected to increase with the progression of aging of the country. Higher dosage of antibiotics has recently been used, and high-dose doripenem (DRPM; 3 g daily) was approved for use in Japan in April 2011. However, there is a lack of data regarding the efficacy and safety of high-dose DRPM in Japan. This study prospectively assessed the clinical efficacy and safety of high-dose DRPM in Japanese patients with refractory pneumonia., Methods: This study was performed at University of Occupational and Environmental Health, Japan and affiliated hospitals. The efficacy and safety of DRPM in patients with pneumonia treated with 3 g daily of DRPM, including those in whom DRPM dosage was increased from 1.5 g to 3 g daily, were evaluated., Results: The safety evaluations included 56 patients, and the efficacy was evaluated in 51 patients. DRPM (3 g daily) treatment showed the response rate of 92.2% (47/51). Adverse effects of DRPM (3 g daily) were observed in 11 of 56 patients (19.7%), and all of these patients improved after DRPM cessation. Two patients had to stop DRPM administration due to elevated aminotransferase levels. The efficacy of DRPM in patients with pneumonia in whom DRPM was increased from 1.5 g daily to 3 g daily was 84.6% (11/13)., Conclusions: High-dose DRPM (3 g daily) treatment is effective and relatively safe in Japanese patients with pneumonia., (Copyright © 2015. Published by Elsevier Ltd.)

A 23-year-old Japanese woman was admitted to A hospital due to pneumonia. IgM for Mycoplasma pneumoniae was positive, and the patient was treated with imipenem/cilastatin, clindamycin, pazufloxacin and minocycline. However, both the chest radiological findings and the symptoms became exacerbated, and she was therefore transferred to our hospital. The bronchoalveolar lavage fluid was obtained, and a 16S rRNA gene sequencing analysis revealed a monobacterial infection of Mycoplasma pneumoniae. Therefore, corticosteroid treatment in addition to minocycline was administered, and the patients symptoms, laboratory data and chest radiographs improved. Corticosteroid therapy may therefore be considered for patients with refractory M. pneumoniae pneumonia.

Introduction: Pneumonia is the third leading cause of mortality in Japan. In 2011, the use of meropenem (MEPM) at 3 g daily was approved to treat refractory infections in Japan. However, little has been reported on the clinical efficacy and safety of this regimen in Japanese patients with refractory infections., Objectives: This study prospectively assessed the clinical efficacy and safety of MEPM (3 g daily) in Japanese patients with refractory pneumonia and/or intrapleural infections., Methods: This study was performed at our university hospital and affiliated hospitals. The plasma concentrations of MEPM before and one and four hours after MEPM administration were also evaluated., Results: A total of 48 patients were enrolled for the efficacy and safety evaluations. The response rate to MEPM (3 g daily) treatment was 90.9% (40/44). Adverse drug reactions were observed in 17 of the 48 patients (20.8%), and all improved after the cessation of MEPM. The plasma MEPM concentration one hour after administering 1 g of MEPM was 44.9 ± 12.0 μg/ml. A pharmacokinetic analysis revealed that the percentage of time above the MIC/24 h for an MIC of 4 μg/ml or 8 μg/ml was more than 50% in 12 of 13 (92%) and in nine of the 13 patients (69%), respectively, indicating sufficient efficacy of 3 g daily of MEPM., Conclusion: Treatment with MEPM (3 g daily) in Japanese patients with refractory pneumonia and/or intrapleural infections is effective, with sufficient plasma concentrations of MEPM, and the treatment has a relatively good safety profile., (Copyright © 2014 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.)

Azithromycin (AZM) is one of 15-membered rings macrolide antibiotics with wide spectrum of antimicrobial efficacy for Gram-positive and -negative bacteria and also atypical bacteria. So far, there had been no reports of the prospective studies evaluating efficacy and safety of AZM infusion in patients with mild or moderate community-acquired pneumonia (CAP). This study was conducted to evaluate prospectively the efficacy and safety of AZM in patients with mild or moderate CAP. AZM 500 mg was intravenously administered once daily, and the clinical efficacy were evaluated by clinical symptoms, peripheral blood laboratory findings and chest X-rays. Sixty-four patients were firstly registered, and eventually 61 and 62 patients were enrolled for the evaluation of clinical efficacy and safety of AZM, respectively. The efficacy of AZM in 61 patients evaluated was 88.5%. In addition, the efficacies of AZM in each pneumonia severity index by A-DROP system by the Japanese Respiratory Society (JRS) guideline in CAP were 85.2% in mild and 91.2% in moderate. Furthermore, the efficacy of AZM in each differentiation between suspicion of bacterial pneumonia and that of atypical pneumonia by JRS guideline in CAP were 91.7% in suspicion of atypical pneumonia, and its efficacy was high than that of bacterial pneumonia. Nineteen patients (20 cases; 15 with liver dysfunction, 4 with diarrhea, 1 with vascular pain) out of 62 patients were reported to have possible adverse effects of AZM. All of the patients with these adverse effects demonstrated mild dysfunction and continued AZM treatment, and these dysfunctions normalized soon after cessation of AZM. In conclusion, AZM is effective drug for patients with mild or moderate CAP, and we believe that it may be one of effective choice in the treatment of CAP patients who need hospitalization.

Levofloxacin (LVFX) is one of respiratory quinolones with wide spectrum of antimicrobial efficacy for Gram-positive and -negative bacteria and also atypical bacteria, and 500 mg of intravenous LVFX infusion has recently been able to use once daily based on pharmacokinetics-pharmacodynamics in Japan. So far, there had been no reports of the prospective studies evaluating efficacy and safety of LVFX in patients with nursing and healthcare-associated pneumonia (NHCAP). This study was conducted to evaluate prospectively the efficacy and safety of LVFX in patients with NHCAP categories B and C (other antibacterial agents were allowed to use with LVFX) according to Japanese guideline for NHCAP by the Japanese Respiratory Society (JRS). LVFX 500 mg was intravenously administered once daily, and the clinical efficacy and safety were evaluated by clinical symptoms, peripheral blood laboratory findings and chest X-rays. Sixty-two patients (average age was 81.2 years old, female/male was 22/40) were firstly registered and evaluated for the safety of LVFX, and eventually 54 patients were enrolled for the evaluation of clinical efficacy of LVFX. The percentage of these 54 patients aged over 65 years old was 96.3%, NHCAP category B/C was 33/21. The efficacy of LVFX in all 54 patients evaluated was 85.2% (categories B/C of NHCAP was 81.8/90.5%). In addition, the efficacies of LVFX in each pneumonia severity category by A-DROP system by JRS in NHCAP patients were 100% in mild, 86.7% in moderate, 77.8% in severe/very severe. Nine patients (2 with liver dysfunction, 6 with renal dysfunction and 1 with thrombocytopenia) out of 62 patients were reported to have possible adverse effects of LVFX. All of the patients with liver and renal dysfunctions after starting LVFX administration demonstrated mild dysfunctions and continued LVFX treatment, and these dysfunctions normalized soon after cessation of LVFX. LVFX was changed to other antibacterial agent in one patient with thrombocytopenia, and also thrombocytopenia was normalized thereafter. In conclusion, LVFX is effective and relatively safe for categories B and C in patients with NHCAP.

A 47-year-old man was referred to our hospital with an abnormal shadow on a chest X-ray. He had a history of untreated chronic sinusitis and suspected ulcerative colitis (UC). Chest CT revealed a diffuse centrilobular granular shadow, while laboratory tests demonstrated an increased proportion of neutrophils; however, no microorganisms were detected in bronchoalveolar lavage fluid. Therefore, sinobronchial syndrome or small airway disease associated with UC was diagnosed, and the patient was treated with long-term erythromycin therapy. Small airway disease associated with UC is usually treated with steroids. Our experience shows that airway involvement in patients with inflammatory bowel disease can be treated with macrolides.

Moxifloxacin (MFLX) is a respiratory quinolone, and is effective against not only Gram-positive and negative bacteria but also anaerobes. There has been no prospective studies evaluating the efficacy and safety of MFLX in patients with nursing and healthcare-associated pneumonia (NHCAP). Therefore, we assessed the efficacy and safety of MFLX in patients with NHCAP. NHCAP patients with mild and moderate severity assessed by the A-DROP system in community-acquired pneumonia guideline proposed by Japan Respiratory Society visited our hospitals from April 2011 to March 2012. Clinical symptoms, chest X-ray films and/or computed tomography, peripheral white and red blood cell and platelet counts, serum CRP, AST, ALT, BUN, creatinine were evaluated. Forty patients were eventually evaluated, and average age was 74.1 years old, male/female were 21/19, 92.5% (37/40) of them had one or more comorbidities. Median duration of MFLX administration was 7.1 days (4-15 days). The efficacy of MFLX in all patients was 87.5% (35/40). The efficacies in each age group were 87.9% (aged over 65 years old), 85.7% (aged under 64 years old), and in each pneumonia severity group by the A-DROP system were 91.7% (mild), 85.7% (moderate). Diarrhea and swelling of the breast were observed in one patient (2.5%) after starting MFLX administration. Mild elevated transaminases were observed in three patients (7.5%), and mild renal dysfunction was observed in two patients (5.0%). All abnormally increased levels of transaminases and serum creatinine were recovered after a cessation of MFLX. MFLX is effective and safe in patients with NHCAP.

We herein report two cases of primary ciliary dyskinesia (PCD) with different responses to macrolides. Case 1: a 17-year-old Japanese man with Pseudomonas aeruginosa infection and combined defect of both inner and outer dynein arms in the cilia was unsuccessfully treated with long-term macrolides (clarithromycin, erythromycin, and azithromycin). Case 2: a 70-year-old Japanese man with deficiency of only the inner dynein arm was successfully treated with clarithromycin. Though the reasons for the different responses to macrolides are unclear, differences of ultrastructural abnormalities of the cilia might be one of the predictive factors in PCD just as in Pseudomonas aeruginosa infection.

We investigated the efficacy and safety of sitafloxacin (STFX) in patients with mild to moderate community-acquired pneumonia or secondary infections of chronic respiratory tract diseases. The results showed that the efficacy rate was 96.5% (111/115) in patients analyzed for efficacy. The efficacy rate by STFX administration method was 93.9% (46/49) at 50mg b.i.d., 100% (37/37) at 100 mg q.d. and 96.6% (28/29) at 100mg b.i.d. In chest X-rays, the image improvement rate in 102 patients with shadows before treatment was 94.1% (96/102). The image improvement rate by STFX administration method was 90.5% (38/42) at 50 mg b.i.d., 97.1% (33/34) at 100mg q.d. and 96.2% (25/26) at 100mg b.i.d. Side effects occurred in five out of 115 patients (4.3%). Abnormalities in hepatic function test values appeared in two patients and abnormalities in renal function test values appeared in three patients. In four cases, the abnormalities were very mild and STFX administration was continued without any treatment. In the other patient, the abnormal value rapidly returned to normal after STFX administration was discontinued. These findings indicated that STFX can be used safety in routine practice by adjusting the administration within the approved dose based on patient characteristics. Good therapeutic effects can be expected in patients with respiratory tract infections.

Background: Rapidly progressive interstitial pneumonia (IP), including acute exacerbation of IP, has a high mortality rate. Direct hemoperfusion with a polymyxin B-immobilized fiber column (PMX-DHP) was recently identified as an effective treatment for sepsis-associated acute respiratory distress syndrome. However, little is known about the effectiveness of PMX-DHP for rapidly progressive IP., Objectives: The present study investigates whether PMX-DHP is safe and effective against rapidly progressive IP., Methods: We retrospectively examined the effects of PMX-DHP in 33 consecutive patients with rapidly progressive IP who were resistant to steroid pulse therapy. Patients were hospitalized at Nagasaki University Hospital between 2006 and 2009., Results: Seventy-two hours after PMX-DHP, the arterial oxygen tension/inspiratory oxygen fraction ratio (median 127-153 mm Hg) had significantly improved. One week after PMX-DHP, the arterial oxygen tension/inspiratory oxygen fraction ratio (median 127-227 mm Hg), the alveolar-arterial difference of oxygen (median 371-177 mm Hg) and the number of positive criteria for systemic inflammatory response syndrome had significantly improved, despite the ineffectiveness of corticosteroid pulse therapy. The serum level of monocyte chemotactic protein 1 was significantly decreased immediately after PMX-DHP., Conclusions: PMX-DHP was safe and effective in improving oxygenation and systemic inflammatory response syndrome in patients with rapidly progressive IP. The beneficial effects of PMX-DHP may be at least partially due to the inhibition of monocyte activation., (Copyright © 2010 S. Karger AG, Basel.)

Background: Idiopathic pulmonary fibrosis (IPF) is characterized by progressive fibrosis and a poor prognosis. Alveolar epithelial cells (AECs) are considered to play important roles by releasing growth factors and matrix metalloproteinases (MMPs) and by being involved in epithelial mesenchymal transition in IPF. Doxycycline hydrochloride (DOXY), an inhibitor of MMPs, attenuates pulmonary fibrosis in models and in patients with IPF; however, the mechanism of this action remains obscure., Objectives: The present study investigated the effect of DOXY on growth factors and MMP production in AECs., Methods: Bleomycin (BL)-induced murine pulmonary fibrosis was treated with DOXY and examined by pathological and immunohistochemical staining. The human alveolar epithelial cell line A549 was stimulated with transforming growth factor (TGF)-β1 and incubated with DOXY, and then the expression of growth factors, MMPs, and collagen type I was evaluated at the mRNA and protein levels. We also evaluated the effects of DOXY on the TGF-β1-induced Smad signaling pathway., Results: DOXY reduced fibrosis scores and the production of collagen type I, connective tissue growth factor (CTGF), and TGF-β1 in BL models. DOXY inhibited the mRNA expression of MMP-2, MPP-9, CTGF, and collagen type I as well as the production of MMP-2 and platelet-derived growth factor-AA protein induced in A549 cells by TGF-β1 but not by Smad2 and Smad3 phosphorylation. We did not find a similar effect of DOXY in normal lung fibroblasts., Conclusions: Our results suggest that DOXY could be useful for attenuating pulmonary fibrosis through the inhibition of growth factors and MMP production in AECs., (Copyright © 2011 S. Karger AG, Basel.)

A 70-year-old woman with a history of sinobronchial syndrome was admitted to the hospital because of a cough, sputum, and abnormal chest shadow. She was diagnosed with pulmonary mucosa-associated lymphoid tissue lymphoma (p-MALToma) based on results of a pathologic examination and the gene rearrangements in the Ig heavy chain on Southern blot hybridization. Although p-MALToma did not regress with conventional therapy, it was reduced after long-term treatment with clarithromycin (CAM) (200 mg/d). A 57-year-old woman with a history of Sjögren syndrome and lymphocytic interstitial pneumonia had a mass lesion in the left lower lung field. CT image-guided biopsy established a diagnosis of p-MALToma. The p-MALToma regressed with long-term treatment with CAM (200 mg/d), whereas Helicobacter pylori (HP) eradication therapy was not effective in concurrent atrophic gastritis with HP. It is suggested that CAM, a macrolide antibiotic, may be effective in some patients with p-MALToma.

Background: Airway mucus hypersecretion is an important problem in chronic respiratory diseases including bronchial asthma. Chlamydophila pneumoniae is recently confirmed to be a pathogen in bronchial asthma, but the relationship between C. pneumoniae and mucus hypersecretion is uncertain. In this study, we examined whether C. pneumoniae induces MUC5AC mucin in airway epithelial cells. We also examined the effects of macrolide and ketolide antibiotics on the C. pneumoniae-induced mucus production., Methods: MUC5AC production in bronchial epithelial cells after stimulation with C. pneumoniae was analyzed by ELISA and quantitative RT-PCR. NF-kappaB and phosphorylated ERK were also analyzed. For inhibition study, cells were pretreated with azithromycin, clarithromycin and telithromycin before stimulation., Results: C. pneumoniae dose-dependently induced MUC5AC production and gene expression. The ERK-NF-kappaB pathway was involved in C. pneumoniae-induced MUC5AC production. Macrolides and ketolides dose-dependently reduced C. pneumoniae-induced MUC5AC production. However, azithromycin was apparently less effective than the other antibiotics. Clarithromycin and telithromycin, but not azithromycin, reduced NF-kappaB activation., Conclusions: Clarithromycin and telithromycin were thought to interfere with the signal pathways between ERK and NF-kappaB. These results suggest that airway mucus hypersecretion is one of the mechanisms of C. pneumoniae-induced bronchial asthma, and that macrolide and ketolide antibiotics represent a novel therapeutic intervention in these patients.

Objectives: Mucus hypersecretion is a prominent feature in patients with chronic respiratory tract infections such as cystic fibrosis and diffuse panbronchiolitis, and the clinical effectiveness of macrolide antibiotics has been reported in these patients. Because human neutrophil peptide-1 (HNP-1), an antimicrobial peptide in neutrophils, exists in high concentrations in the airway fluid of these patients, we examined the direct effect of HNP-1 on MUC5AC mucin production using NCI-H292 cells. The effects of macrolide antibiotics on the response were also examined., Methods: MUC5AC synthesis was assayed using RT-PCR and ELISA. Phosphorylation of ERK1/2 was determined by western blotting., Results: Stimulation with HNP-1 or lipopolysaccharide (LPS) derived from Pseudomonas aeruginosa increases the production of MUC5AC mRNA and protein, and an additive effect was found upon co-stimulation with both HNP-1 and LPS. Azithromycin and clarithromycin had inhibitory effects on overproduction of MUC5AC induced by HNP-1 or LPS stimulation. Telithromycin also had an inhibitory effect on MUC5AC production induced by LPS, but not on production by HNP-1. Phosphorylation of ERK1/2 was induced by HNP-1 or LPS stimulation, and azithromycin, clarithromycin and telithromycin had inhibitory effects on ERK1/2 phosphorylation induced by LPS, but not by HNP-1., Conclusions: These findings suggest that neutrophil-derived defensins as bacterial components contribute to excessive mucus production in patients with respiratory tract infections, and that macrolide and ketolide antibiotics directly inhibit these actions by interfering with intracellular signal transduction. However, the mechanism of telithromycin inhibition of MUC5AC synthesis may differ from the response induced by azithromycin and clarithromycin.

Animals and plants express endogenous peptide antibiotics called defensins. Defensins show broad-spectrum antimicrobial activity, even against bacteria that have resistance to conventional antibiotics, which has made them viable candidates for new antibiotics. However, human defensins have failed to reach the market because of their cytotoxic effects and non-antimicrobial bioactivities. Plectasin is a defensin that has shown promise but has not had its potentially negative effects clarified. To address this issue, we examined plectasin's cytotoxicity in human cells using an AlamarBlue reduction assay, its interleukin (IL)-8-inducing capacity using real-time PCR and ELISA, and measured its MIC against bacteria. We confirmed that plectasin has specific antibacterial activity against Streptococcus pneumoniae. Plectasin showed no cytotoxicity to A549 cells, normal human bronchial epithelial cells, or lung fibroblasts, and it did not induce IL-8 transcription or production in A549 cells. Our results suggest that plectasin could be an inoffensive alternative antibiotic for clinical application.

Amyopathic dermatomyositis (ADM) is a clinical subtype of dermatomyositis, characterized by the absence of motor weakness and the presence of normal muscle enzyme levels. ADM is sometimes accompanied by interstitial pneumonia that shows a rapid progressive course associated with a poor prognosis. We describe a 70-year-old man who presented rapidly progressive interstitial pneumonia associated with clinically ADM (C-ADM); he was successfully treated with polymyxin B-immobilized fiber column (PMX) hemoperfusion.

Summary The macrolide antibiotics are now well known to have anti-inflammatory effects. Because dendritic cells (DCs) orchestrate immune responses, we examined the in vitro effects of clarithromycin (CAM), azithromycin (AZM) and midecamycin (MDM) on the expression of co-stimulatory molecules and production of cytokines [interleukin (IL)-10, IL-6, interferon (IFN)-gamma, IL-12p40, tumour necrosis factor (TNF)-alpha] of murine bone marrow-derived DCs by lipopolysaccharide (LPS) stimulation. A 15-membered macrolide, AZM, and a 14-membered macrolide, CAM, significantly enhanced the intensity of a co-stimulatory molecule, CD80, on DCs but not CD86 and CD40. AZM significantly increased the production of IL-10 and CAM significantly inhibited the production of IL-6 by DCs. However, a 16-membered macrolide, MDM, did not have any significant effect on these surface markers and cytokine productions. Moreover, AZM increased IL-10 and CAM decreased IL-2 productions significantly, when naive T cells derived from spleen were co-cultured with DCs treated in advance with LPS and these macrolides. These findings suggest that 14-membered and 15-membered, but not 16-membered macrolides play as anti-inflammatory agents, at least in part, through modulating the functions of DCs. However, each macrolide affects them in different ways.

The 14-membered macrolides, such as clarithromycin (CAM) and erythromycin (EM), are effective against diffuse panbronchiolitis. However, there have been no studies on the effects of telithromycin (TEL) on chronic respiratory infection in vivo. In this study, we determined the effect of TEL on an experimental murine model of chronic respiratory infection caused by Pseudomonas aeruginosa with biofilm formation. TEL significantly reduced the number of viable bacteria but had no effect on the proliferation of lymphocytes. In contrast, CAM decreased the number of lymphocytes but had no effect on the number of viable bacteria in the lung. These results suggest that TEL and CAM have different effects on chronic respiratory infection caused by P. aeruginosa., (Copyright 2007 S. Karger AG, Basel.)

We previously reported that long-term administration of macrolides (MCL) reduced the number of lymphocytes in bronchoalveolar lavage fluid (BALF) of patients with chronic lower respiratory tract disease. To investigate the anti-inflammatory activity of macrolides, we evaluated their effect on apoptosis of lymphocytes isolated from human peripheral blood. Lymphocytes treated with clarithromycin, azithromycin and josamycin at a final concentration of 200 microg/ml showed positive staining for Annexin V, Fas and Fas ligand using flow cytometry with time at 12-72 h, while other antibiotics did not. Our results suggest that macrolides induce apoptosis of lymphocytes through Fas-Fas ligand pathway and could potentially reduce the number of lymphocytes in the lungs of patients with chronic lower respiratory tract disease.

Diffuse panbronchiolitis (DPB) is a chronic lower respiratory tract infection commonly associated with persistent late-stage Pseudomonas aeruginosa infection. However, low-dose long-term therapy with certain macrolides is effective in most patients with DPB. The present study was designed to examine the effects of long-term erythromycin (ERY) therapy by using our established murine model of chronic respiratory P. aeruginosa infection. ERY or saline was administered from day 80 after intubation with a P. aeruginosa-precoated tube for the subsequent 10, 20, 40, and 80 days. Bacteriologic and histologic analyses of the murine lungs and electron microscopy of the intubated tube were performed. In the murine model, treatment with ERY for 80 days significantly reduced the number of viable P. aeruginosa organisms in the lungs (P < 0.05). The biofilm formed in situ by P. aeruginosa on the inner wall of the inoculation tube placed into the murine bronchus became significantly thinner after 80 days of ERY treatment. We conclude that the clinical efficacy of macrolides in DPB may be due at least in part to the reduction in P. aeruginosa biofilm formation.

Long-term treatment of macrolide antibiotics is considered an effective treatment for diffuse panbronchiolitis (DPB). Although hypersecretion is a common feature of this disease, and it is known that macrolides inhibit mucin production, the mechanism of the effect on mucin production is unclear. The aim of our study was to determine the production of muc5ac core protein, a major core protein of mucin in airway secretion, and the effect of clarithromycin treatment on such production in a mouse model mimicking DPB. Alcian blue-periodic acid-Schiff-positive cells were detected in the lungs of Pseudomonas aeruginosa-infected mice. Western blots of these mice showed muc5ac glycoprotein at day 1 and increased progressively from day 4 to day 14 after inoculation of bacteria. Clarithromycin (10 mg. kg-1. day-1 for 7 days) significantly reduced the muc5ac expression at both the mRNA and protein levels. To investigate the role of molecules upstream in muc5ac regulation, we examined the role of mitogen-activated protein kinase. Extracellular signal-regulated kinase 1/2 phosphorylation increased in the infected lung and decreased after treatment. Our results suggest that overproduction of muc5ac plays an important role in the pathogenesis of DPB and that clinical improvement following macrolide therapy seems to involve, at least in part, its inhibition of mucin overproduction, through modulation of intracellular signal transduction.

Diffuse panbronchiolitis (DPB) can now be cured with long-term erythromycin treatment. Our group conducted a prospective open trial of long-term treatment with a macrolide antibiotic, clarithromycin. We studied ten patients who were treated for 4 years with oral clarithromycin (200 mg once a day). Pulmonary function test, blood gas analysis, comprehensive improvement score, and bacterial culture of sputum were examined at 3, 6, 12 months, and at 2, 3, 4 years after the initiation of the therapy. Pulmonary function improved in most of the patients within 6 months: the forced expiratory volume in one second showed a maximal increase from a mean (SE) value of 1.74 (0.12) l at baseline to 2.31 (0.22) l at 6 months (P < 0.01) and the volume (l) of forced vital capacity also showed a maximal increase within 6 months. The partial pressure of arterial oxygen at rest significantly increased at 3-6 months. The comprehensive improvement score also reached maximum within 6 months in nine of the patients. The majority of patients have developed sputum culture in which bacteria were negative within 6 months after the therapy. All of the patients maintained a stable condition with continued therapy, and no side effects of clarithromycin were observed during the study. This prospective study demonstrated that 6-month treatment with clarithromycin might be necessary to improve the clinical conditions of patients with DPB and the drug could be safely used for a long term.

Fourteen-membered macrolides (e.g. clarithromycin and erythromycin), but not 16-membered macrolides (e.g. josamycin), are effective in diffuse panbronchiolitis. However, there are no studies that have compared the effects of 14- and 16-membered macrolide antibiotics on biofilm formation. Treatment with high-dose clarithromycin (100 mg/kg) resulted in a significant decrease in the number of viable bacteria in an experimental murine model. Josamycin at a dose of up to 100 mg/kg had no effect on the number of viable bacteria in the lung. Our results may explain, at least in part, the clinical efficacy of 14-membered macrolide antibiotics in patients with chronic pneumonia caused by Pseudomonas aeruginosa.

We report the efficacy of oral clarithromycin and inhaled beclomethasone against severe bronchorrhea in a patient with alveolar cell carcinoma. A 54-year-old man produced about 500 to 900 ml of clear and egg-white-like sputum each day. Anti-cancer chemotherapy and erythromycin therapy did not reduce the volume of sputum. After administration of clarithromycin and inhaled beclomethasone, sputum volume decreased to about 300 nl each day and the patient's ability to perform daily activities improved. Two months later, clarithromycin was stopped and the patient was treated with inhaled beclomethasone alone. Sputum volume did not increase for 6 months, although the chestroentgenographic findings gradually worsened. Then the sputum volume gradually increased. Five months after the sputum volume began to increase, he was producing about 2 liters of sputum each day and died of respiratory failure. Although the levels of CA 19-9, SLX, and CEA in serum were all within the normal range, the sputum contained high levels of CA 19-9 (1,133,620 U/ml), SLX (3,000 U/ml), and CEA (283 ng/ml). In patients with bronchorrhea, measurement of tumor markers in sputum may be useful for the diagnosis of alveolar cell carcinoma.