Clinical features of Pseudomonas cepacia pneumonia in an epidemic among immunocompromised patients.

Between January 1990 and August 1991, there were 37 patients admitted to our Department of Internal Medicine with hematologic malignancies or solid tumors who showed colonization of the respiratory tract with Pseudomonas cepacia. Extensive surveillance cultures of the environmental surfaces and respiratory equipment of the hospital revealed that all nebulizing devices were contaminated with P cepacia. To characterize this outbreak, we retrospectively reviewed the medical records of 37 patients colonized with this organism. All had used nebulizers to deliver aerosols containing polymyxin B and amphotericin B as prophylaxis against infection. Sixteen of these 37 patients developed pneumonia, which was caused in 14 by P cepacia. The majority of the 14 patients showed lobular infiltrates on chest x-ray films. Cavity formation and pleural effusion were observed in 4 of the 14 (29 percent). All strains of P cepacia were resistant to piperacillin, cefotiam, sulbactam/cefoperazone, moxalactam (latamoxef), cefuzonam, amikacin, tobramycin, ofloxacin, imipenem, and carumonam. Ceftazidime was effective against 84.7 percent of the strains, while minocycline was effective against 63.5 percent of the strains. This appears to be the first report to describe the clinical features of an epidemic of nosocomial P cepacia pneumonia in immunocompromised patients.

Investigation of nosocomial respiratory infection due to Pseudomonas cepacia by arbitrarily primed polymerase chain reaction.

We used DNA fingerprinting by the arbitrarily primed polymerase chain reaction (AP-PCR) technique for an epidemiologic investigation of Pseudomonas cepacia nosocomial isolates obtained from patients attending our hospital. This approach was compared with conventional phenotypic typing and pulsed-field gel electrophoresis (PFGE). The patterns of gel electrophoresis of the products of AP-PCR differed significantly according to differences in the concentration of Mg2+ and in pH. AP-PCR and PFGE was identical in their resolving power, as the two methods generated four different profiles and identified the same group of strains. The AP-PCR method constitutes an easy alternative to the well-established PFGE method.

Investigation of nosocomial infection caused by arbekacin-resistant, methicillin-resistant Staphylococcus aureus.

An outbreak of coagulase VII-producing, arbekacin (ABK)-resistant, methicillin-resistant Staphylococcus aureus (MRSA) occurred between September 1994 and December 1995, involving five different wards. Twenty-one patients developed skin, wound, drainage, or respiratory tract colonization with coagulase VII-producing, (ABK)-resistant MRSA. Phenotypic characteristics (production of enterotoxin and TSST-1, antimicrobial susceptibility) and molecular-typing procedure (plasmid DNA profile, pulsed-field gel electrophoresis [PFGE] and arbitrarily primed polymerase chain reaction [AP-PCR] of chromosomal DNA) in isolated strains were compared. Plasmid analysis identified four different profiles and 19 of 22 strains recovered had identical patterns. PFGE of chromosomal DNA identified three different subtypes and 18 (81.8%) isolates shared the same subtype. AP-PCR also demonstrated that most strains had the same phenotypic characteristics. Although traditional epidemiological methods; for example, coagulase typing, plays a central role in hospital infection control, combination of plasmid DNA profile, AP-PCR, and PFGE may prove to be a particularly informative means of tracking the nosocomial spread of MRSA.

Nosocomial contamination by Mycobacterium gordonae in hospital water supply and super-oxidized water.

We experienced contamination by Mycobacterium gordonae of the hospital water of our surgical ward. The contamination was discovered following detection of the organism in operative lung samples, washed with super-oxidized water. Repeated examination of water demonstrated contamination by M. gordonae occurred only in the surgical ward, related to the apparatus for making super-oxidized water. No patients were infected by M. gordonae. After changing the water supply equipment and cleaning the water tubes, M. gordonae in the water disappeared.

Eradication of contaminating Mycobacterium chelonae from bronchofibrescopes and an automated bronchoscope disinfection machine.

The results of a follow-up study concerning the decontamination of Mycobacterium chelonae subspecies abscessus from the bronchofibrescopes and the automated bronchoscope disinfection machine are described in this paper. After modification of the methods for disinfecting the bronchofibrescopes (adding a disinfection procedure with 70% alcohol before using the automated bronchoscope disinfection machine, increasing glutaraldehyde concentration to 3%, and changing the glutaraldehyde solution once a week), and the automated bronchoscope disinfection machine (recirculating used disinfectant), M. chelonae has not been detected from either the bronchofibrescopes or the automated bronchoscope disinfection machine (examined every 6 months for 4 yr by microscopy and cultures). Moreover, no M. chelonae has been clinically detected from bronchial washings for 4 yr.

Clinical features of Stenotrophomonas maltophilia pneumonia in immunocompromised patients.

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.

[Contamination of endoscopes and endoscope washers by atypical mycobacteria].

Contamination of endoscopes and endoscope washers by atypical mycobacteria was studied. Large amounts of atypical mycobacteria were detected with high frequency inside endoscopes and endoscope washers. The species of atypical mycobacteria was Mycobacterium chelonae subsp. abscessus. Antibacterial-effects of glutaraldehyde against isolated atypical mycobacteria were checked. Sufficient antibacterial-effect was not obtained by 2% glutaraldehyde solution for endoscope sterilization. However, after frequent manual washing and brushing of endoscopes, by using 3% glutaraldehyde solution and 70% alcohol, all endoscopic instruments were completely decontaminated. We must pay attention to contamination of endoscopes and endoscope washer at least once a month.

[DNA fingerprinting by arbitrarily primed polymerase chain reaction (AP-PCR) for methicillin-resistant Staphylococcus aureus].

Recently, nosocomial outbreaks of MRSA have become an important social problem in Japan. To examine the routes of transmission of MRSA, the establishment of accurate MRSA typing system is essential. However, more recently, because MRSA strains with type II coagulase have been increasing, it is difficult to discriminate MRSA strains by the coagulase typing method. Under this background, our study was designed to evaluate the clinical significance of DNA fingerprinting by arbitrarily primed polymerase chain reaction (AP-PCR). Several MRSA strains isolated from patients in our department were used in this study. To optimize the condition of AP-PCR, the differences of amplified products by AP-PCR were evaluated according to the following conditions: extracting methods of DNA from MRSA strains, buffer conditions, the temperature of AP-PCR, cycles of AP-PCR, and several primers. As a result, the optimal conditions of AP-PCR were as follows: extracted DNA using the InstaGene kit, amplified DNA by two-step AP-PCR using a M13 reverse primer with a buffer condition of 3.5 mM of magnesium chloride, and a pH of 8.5. The results of AP-PCR correlated well with the results of pulsed-field gel electrophoresis. In conclusion, DNA fingerprinting by AP-PCR seems to be useful in examining the nosocomial MRSA outbreak.

[Clinical utility of DNA fingerprinting by arbitrarily-primed polymerase chain reaction (AP-PCR) in nosocomial infection caused by methicillin-resistant Staphylococcus aureus].

Recently, nosocomial outbreaks of MRSA have become an serious social problem in Japan. To examine the routes of transmission of MRSA, the establishment of an accurate MRSA typing system is essential. Previously, we reported that the DNA fingerprinting by AP-PCR might be a useful method to differentiate MRSA strains. In this study, we tried to investigate the clinical usefulness of DNA fingerprinting by AP-PCR using clinically-isolated MRSA strains. Twenty-four MRSA strains (12 with coagulase type IV, and 12 with coagulase type II) isolated from patients in our department were used. Other typing methods (the sensitivity of antibiotics, pulsed-field gel electrophoresis, and plasmid analysis) were also performed. As a result, the typing pattern by AP-PCR correlated well with other typing methods. MRSA strains with coagulase type IV showed almost the same pattern, suggesting that these strains were nosocomially transmitted. On the other hand, MRSA strains with coagulase type II showed various patterns, suggesting these strains were not nosocomially transmitted. In conclusion, the typing by AP-PCR seemed to be a useful tool evaluate a nosocomial MRSA transmission.

[Effect of erythromycin on macrophage functions].

Recently, it has been suggested that macrolide antibiotics act as immunomodulators. In this study, we evaluated the effect of EM on macrophage function. We used the mouse macrophage cell line, J774.1. The following direct effects of EM on macrophage function were evaluated: chemotaxis to EM, chemokinetic effect by EM, and the effect of EM on macrophage growth. In order to examine the indirect effects of EM on macrophage functions, we preincubated macrophages with several concentrations of EM and then removed the EM. Thereafter, the phagocytosis of beads, cytocidal activity against Candida albicans, and chemotaxis to lipopolysaccharide were evaluated. EM (at the concentration between 0.04 and 0.2 microgram/ml) directly stimulated macrophage chemotaxis and chemokinesis. In addition, EM dose-dependently stimulated the growth of macrophages. EM pretreatment (for 4 hours at the contractions between 0.04 and 0.2 microgram/ml) stimulated macrophage phagocytosis, cytocidal activity against Candida albicans, and chemotaxis to lipopolysaccharide. These results suggest that EM has direct and indirect effects on macrophage functions.

[Effect of clarithromycin on macrophage functions].

Recently, it has been suggested that macrolide antibiotics act as immunomodulators. In this study, we evaluated the effect of clarithromycin (CAM) on macrophage function. We used the mouse macrophage cell line, J774.1. The following direct effects of CAM on macrophage function were evaluated: chemotaxis to CAM, chemokinetic effect of CAM, and the effect of CAM on macrophage growth. In order to examine the indirect effects of CAM on macrophage functions, we preincubated macrophages with several concentrations of CAM and then removed the CAM. Thereafter, the phagocytosis of beads, cytocidal activity against Candida albicans, and chemotaxis to lipopolysaccharide were evaluated. In addition, the indirect effects of CAM on endoxan (4 mg/ml) treated macrophage phagocytosis, cytocidal activity, and chemotaxis were evaluated. CAM (at the concentration between 0.04 and 0.2 microgram/ml) directly stimulated macrophage chemotaxis and chemokinesis. In addition, CAM dose-dependently stimulated the growth of macrophages. CAM pretreatment (for 4 hours at the concentrations between 0.04 and 0.2 microgram/ml) stimulated macrophage phagocytosis, cytocidal activity against Candida albicans, and chemotaxis to lipopolysaccharide. In addition, CAM recovered macrophage phagocytosis, cytocidal activity, and chemotaxis which were decreased after endoxan exposure. These results suggest that CAM has direct and indirect effects on macrophage functions.

Experimental pneumonia produced by clinical isolates of Pseudomonas cepacia in mice.

An experimental Pseudomonas cepacia lung infection was induced in ddY mice pretreated with cyclophosphamide. A single dose of 250 mg of cyclophosphamide per kg resulted in leukopenia which lasted for four days. At the lowest PMN levels, the mice were exposed to various doses of bacteria by either intratracheal inoculation or aerosol inhalation. Experimental pneumonia was established by intratracheal inoculation of 1 x 10(7) - 2 x 10(8) colony-forming units of P. cepacia. The duration of survival time of the mice and the number of viable bacteria in their lungs were determined. A dramatic rise in the viable counts of P. cepacia was found within 24 hours after intratracheal inoculation of 1 x 10(8) colony-forming units of P. cepacia. It was impossible to establish P. cepacia pneumonia by aerosol inhalation, since the bacteria were immediately cleared from the lung. Mice which had not been treated with cyclophosphamide remained healthy and did not show any lung lesions. Thus, neutrophils appear to play an important role in the early defense mechanisms of the lung against P. cepacia. This animal model could be of use in evaluating additional therapies for the infection, and the pathologic determinants of infection caused by P. cepacia.

Nosocomial outbreak of Pseudomonas cepacia respiratory infection in immunocompromised patients associated with contaminated nebulizer devices.

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 extracellular 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.

[Epidemiological study on nosocomial infection of Pseudomonas cepacia by plasmid analyses].

In order to clarify the usefulness of plasmid analyses in epidemiological study, plasmid DNA profiles, restriction fragment patterns of chromosomal DNA analysed by pulsed-field gel electrophoresis (PFGE), and patterns of extracellular products were performed in twenty-four nosocomial strains of Pseudomonas cepacia isolated at the Kagawa Medical School Hospital. Fifteen strains were obtained from 15 patients admitted in A ward, three strains were obtained from nebulizer devices used in A ward, 5 strains were obtained from 5 patients admitted in B ward, and 1 strain was obtained from a patient admitted in C ward. Three different patterns which differed from ward to ward were clearly distinguished by PFGE patterns and patterns of extracellular products. On the other hand, plasmid DNA profiles were different in some strains obtained from B ward. These results suggested that plasmid analyses combined with other typing methods are useful in more precise epidemiological analysis on nosocomial infection of P. cepacia.

[Nationwide sensitivity surveillance of various antibiotic activities against bacteria isolated from patients with severe infections].

The susceptibility of 3,058 bacterial strains isolated between January and March, 1997 from patients with severe infections in Japan to ciprofloxacin and other injectable antimicrobial agents was measured using broth microdilution method. Methicillin-resistant Staphylococcus aureus (MRSA) strains were generally sensitive to vancomycin, teicoplanin and arbekacin, and resistant to CPFX and other antibacterial agents. MIC90 of CPFX against Streptococcus pneumoniae, to which MIC of ampicillin was more than 4 micrograms/mL, was below 2 micrograms/mL. PRSP (Penicillin resistant S. pneumoniae), which was also resistant to cephalosporins and carbapenems, showed no cross-resistance to CPFX. The susceptibility of Gram-negative bacteria to CPFX was as high as that to carbapenems. Especially, MIC90 against Pseudomonas aeruginosa was 2 micrograms/mL. 3 strains of isolated 446 P. aeruginosa strains had blaIMP gene. CPFX and pazufloxacin demonstrated good susceptibility with 0.25 microgram/mL of MIC to 2 strains of these 3 strains. The susceptibility rate of the most common isolates from patients suffering from lower respiratory tract infections excluding MRSA to CPFX was more than 80% (indication: % strains < pneumonia break point).

[Activities of antimicrobial agents against 5,180 clinical isolates obtained from 26 medical institutions during 1998 in Japan. Levofloxacin--Surveillance Group].

The surveillance study was conducted to determine the antimicrobial activity of fluoroquinolones (ofloxacin, levofloxacin, ciprofloxacin, tosufloxacin) and other 20 antimicrobial agents against 5,180 clinical isolates obtained from 26 medical institutions during 1998 in Japan. The resistance to fluoroquinolones was remarkable in Enterococci, methicillin-resistant staphylococci and Pseudomonas aeruginosa from UTI. However, many of the common pathogens such as Streptococcus pneumoniae including penicillin-resistant isolates, methicillin-susceptible Stahylococcus aureus, Moraxella catarrhalis, the family of Enterobacteriaceae, Haemophilus influenzae including ampicillin-resistant isolates have been kept to be susceptible to fluoroquinolones. About 90% of P. aeruginosa isolates from RTI were susceptible to fluoroquinolones. In conclusion, the results from this surveillance study suggest that fluoroquinolones are useful in the treatment of various bacterial infections including respiratory infections.

[Clinical feature of male non-gonorrhoea urethritis and minocycline treatment of Chlamydia or Ureaplasma-infected urethritis].

Thirty-nine male patients with urethritis were studied for gonorrhoea or non-gonorrhoea infections. Only 2 patients were infected with N. gonorrhoeae, the other 37 patients were non-gonorrhoea urethritis (NGU). In 9 of these patients, C. trachomatis was identified and in 6 patients, U. urealyticum was isolated. No chlamydial urethritis was combined with ureaplasma. There was no clinical difference between chlamydia and ureaplasma infection, such as serous urethral discharge or mild pyuria. Minocycline was given orally at the dose of 200 mg daily for 7 to 42 days to these patients. Seven of the 9 patients (78%) with C. trachomatis and 7 of the 6 patients (67%) with U. urealyticum infection showed improvement of subjective and objective symptoms after minocycline. In no case, was an adverse reaction noted. Minocycline was effective in the treatment of both C. trachomatis and U. urealyticum urethral infection.

Behavioral development of infant holding and its laterality in relation to mothers' handedness and child-care attitude.

The holding of 465 Japanese infants by their mothers was longitudinally observed at 4 and 9 months with several checkups and questionnaires of physical and psychological development and child-care attitude in a larger longitudinal study of mother-child relationships. A left side bias in holding was significant for the 4-month-old infants. The infants' increased autonomy in their ability to adopt a posture at 9 months weakened the holding bias. The mothers' handedness was related to different right/left hand contact patterns, but it was significant only for holding on the left side. The infants' reflexes relating to posture did not correlate with the holding bias at 4 months. The meaning and possible determinants of holding laterality are discussed.