Between January 1988 and December 1992, 68 patients admitted to our Department of Internal Medicine with haematological malignancies or solid tumours showed colonization of the respiratory tract with Stenotrophomonas maltophilia. To characterize the significance of respiratory tract colonization by S. maltophilia, we retrospectively reviewed the medical records of the 68 patients colonized with this organism. Twenty-nine of these 68 patients developed pneumonia, with S. maltophilia being implicated in 10 cases. The majority of these 10 patients showed lobular infiltration on chest X-ray. Pleural effusion was observed in two (20%) of the 10 patients. All 68 strains of S. maltophilia were resistant to imipenem. Latamoxef was effective against 98 center dot 5% of strains, while minocycline was effective against 100% of strains. This report describes the clinical features of nosocomial S. maltophilia pneumonia in immunocompromised patients.

Macrolide antibiotics have a variety of actions other than antimicrobial activities. Recently, it has been suggested that macrolide antibiotics act as immunomodulators.In this study, we evaluated the effects of macrolide antibiotics on macrophage functions.For the macrophage, we used the mouse macrophage cell line J774.1. The following effects of macrolide antibiotics on macrophage functions were evaluated: the effect of macrolide antibiotics on macrophage growth; the phagocytosis of beads; cytocidal activity against Candida albicans; and chemotaxis to lipopolysaccharide (LPS). Macrolide antibiotics except for azithromycin significantly stimulated the growth of the macrophage. In addition, pretreatment with macrolide antibiotics except for roxithromycin significantly stimulated the macrophage phagocytosis of beads, macrophage chemotaxis to LPS, and macrophage cytocidal activity against Candida albicans. These results suggest that macrolide antibiotics stimulate macrophage functions. There is increasing evidence that long-term administration of the macrolide antibiotic erythromycin (EM) is effective in the treatment of chronic respiratory infections, probably through actions other than its antimicrobial properties (19). Although the mechanism of the efficacy is uncertain, several hypotheses have been proposed, such as the immunomodulatory action of macrolide antibiotics. Macrolide antibiotics modulate the functions of inflammatory cells such as polymorphonuclear leukocytes, lymphocytes and macrophages (1, 33). In addition, macrolide antibiotics directly affect airway secretory cell (12) and epithelial cell (35) functions. These effects are proposed to explain the efficacy of macrolides in the treatment of inflammatory airway diseases. Several studies have been conducted concerning the interaction between phagocytic cells and macrolide antibiotics. However, there are few reports that evaluate the interaction between macrophage functions and several macrolide antibiotics. With this background, we evaluated various aspects of the interaction between four macrolide antibiotics and macrophages. These studies included the effect on growth, effect on phagocytic activity, effect on chemotaxis to lipopolysaccharide (LPS), and effect of cytotoxicity against Candida albicans. Materials and MethodsMacrophage. We used a murine macrophage cell line, J774.1. This cell line was obtained from the RIKEN Cell Bank (Ibaraki, Japan). This cell line was cultured in RPMI-1640 medium with 10% fetal bovine serum (FBS).Antibiotics. The EM (Japan Dynabot Co., Tokyo), clarithromycin (CAM, Japan Dynabot Co.), roxithromycin (RXM, Roussel Uclaf, Paris, France), and azithromycin (AZM, Pfizer Pharmaceuticals Inc., Japan) were provided by the respective manufacturers. These 4 drugs were dissolved in 90% methanol at a concentration of 2 mg/ml as a stock solution; then diluted with RPMI-1640 medium with 10% FBS. Several final concentrations of macrolide antibiotics (4 concentrations of each antibiotic) were used in the following experimen...

For the purpose of nationwide surveillance of antimicrobial susceptibility of bacterial respiratory pathogens from patients in Japan, the Japanese Society of Chemotherapy (JSC) started a survey in 2006. From 2009, JSC continued the survey in collaboration with the Japanese Association for Infectious Diseases and the Japanese Society for Clinical Microbiology. The fourth-year survey was conducted during the period from January and April 2009 by the three societies. A total of 684 strains were collected from clinical specimens obtained from well-diagnosed adult patients with respiratory tract infections. Susceptibility testing was evaluable with 635 strains (130 Staphylococcus aureus, 127 Streptococcus pneumoniae, 4 Streptococcus pyogenes, 123 Haemophilus influenzae, 70 Moraxella catarrhalis, 78 Klebsiella pneumoniae, and 103 Pseudomonas aeruginosa). A maximum of 45 antibacterial agents including 26 β-lactams (four penicillins, three penicillins in combination with β-lactamase inhibitors, four oral cephems, eight parenteral cephems, one monobactam, five carbapenems, and one penem), four aminoglycosides, four macrolides (including ketolide), one lincosamide, one tetracycline, two glycopeptides, six fluoroquinolones, and one oxazolidinone were used for the study. Analysis was conducted at the central reference laboratory according to the method recommended by the Clinical and Laboratory Standard Institute (CLSI). Incidence of methicillin-resistant S. aureus (MRSA) was as high as 58.5 %, and that of penicillin-intermediate and penicillin-resistant S. pneumoniae (PISP and PRSP) was 6.3 % and 0.0 %, respectively. Among H. influenzae, 21.1 % of them were found to be β-lactamase-non-producing ampicillin (ABPC)-intermediately resistant (BLNAI), 18.7 % to be β-lactamase-non-producing ABPC-resistant (BLNAR), and 5.7 % to be β-lactamase-producing ABPC-resistant (BLPAR) strains. A high frequency (76.5 %) of β-lactamase-producing strains has been suspected in Moraxella catarrhalis isolates. Four (3.2 %) extended-spectrum β-lactamase-producing K. pneumoniae were found among 126 strains. Four isolates (2.5 %) of P. aeruginosa were found to be metallo-β-lactamase-producing strains, including three (1.9 %) suspected multi-drug resistant strains showing resistance against imipenem, amikacin, and ciprofloxacin. Continuous national surveillance of the antimicrobial susceptibility of respiratory pathogens is crucial to monitor changing patterns of susceptibility and to be able to update treatment recommendations on a regular basis.

The nationwide surveillance on antimicrobial susceptibility of bacterial respiratory pathogens from patients in Japan, was conducted by Japanese Society of Chemotherapy, Japanese Association for Infectious Diseases and Japanese Society for Clinical Microbiology in 2010. The isolates were collected from clinical specimens obtained from well-diagnosed adult patients with respiratory tract infections during the period from January and April 2010 by three societies. Antimicrobial susceptibility testing was conducted at the central reference laboratory according to the method recommended by Clinical and Laboratory Standard Institutes using maximum 45 antibacterial agents. Susceptibility testing was evaluable with 954 strains (206 Staphylococcus aureus, 189 Streptococcus pneumoniae, 4 Streptococcus pyogenes, 182 Haemophilus influenzae, 74 Moraxella catarrhalis, 139 Klebsiella pneumoniae and 160 Pseudomonas aeruginosa). Ratio of methicillin-resistant S. aureus was as high as 50.5%, and those of penicillin-intermediate and-resistant S. pneumoniae were 1.1% and 0.0%, respectively. Among H. influenzae, 17.6% of them were found to be b-lactamase-non-producing ampicillin (ABPC)-intermediately resistant, 33.5% to be b-lactamase-non-producing ABPC-resistant and 11.0% to be b-lac-tamase-producing ABPC-resistant strains. Extended spectrum b-lactamase-producing K. pneumoniae and multi-drug resistant P. aeruginosa with metallo b-lactamase were 2.9% and 0.6%, respectively. Continuous national surveillance of antimicrobial susceptibility of respiratory pathogens is crucial in order to monitor changing patterns of susceptibility and to be able to update treatment recommendations on a regular basis.

From May 1990 to August 1991, 36 patients admitted to the Department of Internal Medicine in a medical school hospital with hematological malignancies or solid tumors, developed respiratory tract colonization with Pseudomonas cepacia. Sixteen (44.4%) of these patients developed pneumonia, and four (11.1%) died of respiratory failure due to P. cepacia pneumonia. Extensive survey of the hospital environment as well as equipment showed that nebulizer devices used by the patients for inhalation were contaminated with P. cepacia. Phenotypic characteristics, (production of hemolysin and extracelluler enzymes [lipase, lecithinase and protease]), the Analytical Profile Index 20 NE pattern, and the pattern of DNA fingerprinting by pulse-field gel electrophoresis in clinically isolated strains and strains derived from nebulizer devices were compared. The strains of P. cepacia obtained from patients in the Department of Internal Medicine were indistinguishable from each other and also from those isolated from nebulizer devices, but were different from those isolated from patients in other departments at the same time. These results demonstrated that the outbreak of P. cepacia respiratory colonization in immunocompromised patients was a nosocomial acquisition, and probably occurred by transmission through contaminated nebulizer devices.