-
Y Hirakata,
K Izumikawa,
T Yamaguchi,
H Takemura, H Tanaka,
R Yoshida,
J Matsuda,
M Nakano,
K Tomono,
S Maesaki,
M Kaku,
Y Yamada,
S Kamihira,
S Kohno
[show abstract]
[hide abstract]
ABSTRACT: Gram-negative rods (GNR) carrying the transferable carbapenem resistance gene blaIMP, including Pseudomonas aeruginosa and Serratia marcescens, have been isolated from more than 20 hospitals in Japan. Although the emergence of such multiple-drug-resistant bacteria is of utmost clinical concern, little information in regard to the distribution of blaIMP-positive GNR in hospitals and the clinical characteristics of infected patients is available. To address this, a system for the rapid detection of the blaIMP gene with a simple DNA preparation and by enzymatic detection of PCR products was developed. A total of 933 ceftazidime-resistant strains of GNR isolated between 1991 and 1996 at Nagasaki University Hospital, Nagasaki, Japan, were screened for the blaIMP gene; 80 isolates were positive, including 53 P. aeruginosa isolates, 13 other glucose-nonfermenting bacteria, 13 S. marcescens isolates, and 1 Citrobacter freundii isolate. Most of the patients from whom blaIMP-positive organisms were isolated had malignant diseases (53. 8%). The organisms caused urinary tract infections, pneumonia, or other infections in 46.3% of the patients, while they were just colonizing the other patients evaluated. It was possible that blaIMP-positive P. aeruginosa strains contributed to the death of four patients, while the other infections caused by GNR carrying blaIMP were not lethal. DNA fingerprinting analysis by pulsed-field gel electrophoresis suggested the cross transmission of strains within the hospital. The isolates were ceftazidime resistant and were frequently resistant to other antibiotics. Although no particular means of pathogenesis of blaIMP-positive GNR is evident at present, the rapid detection of such strains is necessary to help with infection control practices for the prevention of their dissemination and the transmission of the resistance gene to other pathogenic bacteria.
Antimicrobial Agents and Chemotherapy 09/1998; 42(8):2006-11. · 4.84 Impact Factor
-
K Izumikawa,
Y Hirakata,
T Yamaguchi,
R Yoshida, H Tanaka,
H Takemura,
S Maesaki,
K Tomono,
M Kaku,
K I Izumikawa,
S Kamihira,
S Kohno
[show abstract]
[hide abstract]
ABSTRACT: The in vitro activities of quinupristin-dalfopristin and streptogramin RPR 106972 were determined with 44 strains of Mycoplasma pneumoniae and compared to those of macrolides, minocycline, and quinolones. All isolates tested were highly susceptible to macrolides and to quinupristin-dalfopristin (MIC at which 90% of the isolates are inhibited [MIC90], 0.0625 microg/ml), followed by RPR 106972 (MIC90, 0.5 microg/ml), quinolones, and minocycline.
Antimicrobial Agents and Chemotherapy 03/1998; 42(3):698-9. · 4.84 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Pulsed field gel electrophoresis (PFGE) of the genomic DNA of penicillin resistant serotype 19B Streptococcus pneumoniae was carried out. Thirteen strains form the Nagasaki area and 12 strains from other areas in Japan were examined. Twenty-three strains were resistant to erythromycin, tetracycline and trimethoprim/sulfamethoxazole but susceptible to chloramphenicol. Eight strains were resistant to ceftriaxone. All strains were multiply resistant. Five strains isolated from Nagasaki were indistinguishable from each other by using restriction enzymes Apa I and Sma I. Two strains isolated from other areas were indistinguishable from the above five strains. We could classify 13 Nagasaki strains into 3 groups and the total of 25 Japanese strains into 6 groups. These results suggest that the increasing prevalence of multiply drug resistant S. pneumoniae serotyped 19B in Japan is not due to a single clone, but at least one clone has spread widely in Japan.
Epidemiology and Infection 05/1997; 118(2):105-10. · 2.84 Impact Factor
-
H Takemura,
M Kaku,
S Kohno,
Y Hirakata, H Tanaka,
R Yoshida,
K Tomono,
H Koga,
A Wada,
T Hirayama,
S Kamihira
[show abstract]
[hide abstract]
ABSTRACT: Defensins are small cationic bactericidal peptides present abundantly in the granules of polymorphonuclear neutrophils (PMNs). Human PMNs contain four defensins termed HNP-1 to HNP-4. We used a new assay system in agar plates, the radial diffusion assay, to evaluate the effects of human defensins against gram-positive and -negative bacteria. A crude mixture of HNP-1, -2, and -3 (crude HNPs) was purified from human PMN extracts by reversed-phase high-pressure liquid chromatography (RP-HPLC). The different components were later separated by RP-HPLC and gel permeation chromatography. We compared the antibacterial activities of purified HNP-1, -2, and -3 against Escherichia coli, Pseudomonas aeruginosa, methicillin-susceptible Staphylococcus aureus, and methicillin-resistant S. aureus strains using the radial diffusion assay. The antibacterial activities of HNP-1 and HNP-2 against all strains tested were similar to those of the crude HNPs, but the activity of HNP-3 was less than those of the other defensins. To quantitate the activities of HNPs against different bacteria, we defined the minimal dose of crude HNPs forming a detectable clear zone around the bacteria as the minimal inhibitory dose (MID) and determined the MIDs for 10 strains of E. coli, 12 strains of P. aeruginosa, 10 strains of methicillin-susceptible S. aureus, and 12 strains of methicillin-resistant S. aureus isolates, including clinical isolates. In general, the MIDs of the HNPs were similar against similar bacterial species. However, the MIDs for P. aeruginosa were higher than those for the other organisms tested. The radial diffusion assay is suitable as a screening test for measuring the susceptibilities of isolates to defensins, because it is sensitive and simple and has good reproducibility.
Antimicrobial Agents and Chemotherapy 11/1996; 40(10):2280-4. · 4.84 Impact Factor
-
H Tanaka,
Y Hirakata,
M Kaku,
R Yoshida,
H Takemura,
R Mizukane,
K Ishida,
K Tomono,
H Koga,
S Kohno,
S Kamihira
[show abstract]
[hide abstract]
ABSTRACT: We tested the antimicrobial activity of superoxidized water against methicillin-sensitive Staphylococcus aureus, methicillin-resistant Staphylococcus aureus, Staphylococcus epidermidis, Serratia marcescens, Escherichia coli, Pseudomonas aeruginosa and Burkholderia cepacia. The number of bacteria was reduced below detection limit following incubation in superoxidized water for 10 s. The bactericidal activity of superoxidized water was similar to that of 80% ethanol, but superior to that of 0.1% chlorhexidine and 0.02% povidone iodine. We conclude that superoxidized water is a low cost but powerful disinfectant.
Journal of Hospital Infection 10/1996; 34(1):43-9. · 3.39 Impact Factor
-
H Koga,
K Tomono,
Y Hirakata,
S Kohno,
K Abe,
S Kawamoto,
S Kusano,
K Tanaka,
N Morikawa,
H Sugiyama, [......],
Y Matsumoto,
Y Inoue,
M Ishiguro,
H Hori,
H Mashimoto,
Y Dotsu, H Tanaka,
Y Imamura,
T Kanda,
K Hara
[show abstract]
[hide abstract]
ABSTRACT: The efficacy and safety of sulbactam/cefoperazone (SBT/CPZ) were evaluated in 42 patients with respiratory tract infections, including pneumonia (29 patients) and lower respiratory tract infections (5 patients). Overall clinical efficacy rates (excellent + good) were 79% in pneumonia and 80% in respiratory tract infections in 34 patients evaluated for clinical efficacy. It was excellent that the clinical efficacy rate was 92% in mild and moderate pneumonia. Pathogens isolated from sputa were 31 strains, including 8 strains of Pseudomonas aeruginosa, 7 of Streptococcus pneumoniae, 3 of Staphylococcus aureus and 3 of Haemophilus influenzae. Since the isolates were eradicated in 18 strains, replaced in 3, unchanged in 2 and unknown in 8, the overall eradication rate was 91%. The eradication rates were 89% in beta-lactamase producing strains and 100% in beta-lactamase positive sputum, and excellent or good in 19 (83%) of 23 patients with beta-lactamase negative sputum. The eradication rate was 88% in 5 patients with beta-lactamase positive sputum. One patient experienced a moderate rash. Abnormal laboratory test values were observed in 10 patients (26.3%), but these abnormalities were mild and transient. These results suggested that SBT/CPZ was effective and safe for the treatment of respiratory tract infections caused by beta-lactamase producing as well as beta-lactamase non-producing bacteria.
The Japanese journal of antibiotics 09/1996; 49(8):800-7.
-
[show abstract]
[hide abstract]
ABSTRACT: A total of 184 isolates of Streptococcus pneumoniae were recovered from the sputa of patients over a 5-year period in the Nagasaki area and were examined. A total of 30 strains were resistant to penicillin (MIC, > or = 0.10 micrograms/ml), 13 of which belonged to serotype 19B. These strains showed decreased susceptibility to other antimicrobial agents. Vancomycin, cefpirome, and imipenem were the most active agents tested.
Antimicrobial Agents and Chemotherapy 06/1995; 39(5):1196-8. · 4.84 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: We investigated the in-vitro and in-vivo activity of a new quinolone AM-1155 against Mycoplasma pneumoniae, and compared it with ofloxacin, ciprofloxacin, lomefloxacin, tosufloxacin, erythromycin and minocycline. AM-1155 was the most potent agent in vitro of the quinolones tested. Its pre-treatment minimal inhibitory concentrations for 90% of the 41 strains (MIC90) was 0.06 mg/L. In contrast, pre-treatment MIC90 values for ofloxacin, ciprofloxacin, lomefloxacin, tosufloxacin, erythromycin, and minocycline were 1, 1, 2, 0.5, 0.0156, and 0.5 mg/L, respectively. Post-treatments MIC90s, which may reflect mycoplasmacidal potency, of AM-1155, ofloxacin, ciprofloxacin, lomefloxacin, tosufloxacin, erythromycin and minocycline were 0.125, 1, 2, 4, 0.5, 0.125 and 4 mg/L, respectively. In-vitro activities of antimicrobial agents were assessed in an experimental pulmonary infection model in Syrian golden hamsters. AM-1155 was the most effective agent among five antimicrobial agents (AM-1155, ofloxacin, tosufloxacin, erythromycin, minocycline) tested in terms of reduction in viable M. pneumoniae cells and in reducing macroscopic lung lesions. These results suggest that AM-1155 will be a useful antimicrobial agent for the treatment of M. pneumoniae infections.
Journal of Antimicrobial Chemotherapy 01/1995; 34(6):875-83. · 5.07 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The in vitro and in vivo activities of sparfloxacin against Mycoplasma pneumoniae were compared with those of erythromycin, levofloxacin, ofloxacin, and minocycline. The MICs of sparfloxacin, erythromycin, levofloxacin, ofloxacin, and minocycline for 90% of the 43 M. pneumoniae strains tested were 0.063, 0.016, 0.5, 1, and 0.5 microgram/ml, respectively. In the experimental pulmonary M. pneumoniae infection model in Syrian golden hamsters, sparfloxacin was as effective as erythromycin when orally administered at 15 mg/kg twice daily for 5 days and more effective than erythromycin when orally administered at 10 mg/kg once daily for 5 days. Sparfloxacin was more effective than levofloxacin and ofloxacin in both dosing regimens. The peak concentrations of sparfloxacin in hamster sera after administration of single oral doses of 15 mg/kg were almost the same as those in human sera after administration of single oral doses of 200 mg (the usual clinical dose), and the half-life of sparfloxacin in hamster serum was shorter than that in human serum after administration of a single oral dose of 200 mg. These results suggest that sparfloxacin may be clinically useful for the treatment of M. pneumoniae infections.
Antimicrobial Agents and Chemotherapy 05/1994; 38(4):738-41. · 4.84 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: We investigated the in vitro and in vivo activities of macrolides against Mycoplasma pneumoniae. In vitro MICs of azithromycin, erythromycin, clarithromycin, and roxithromycin were determined. Azithromycin was the most potent antimicrobial agent tested in vitro. Its MIC for 90% of the strains was 0.00024 micrograms/ml. MICs for 90% of the strains of erythromycin, clarithromycin, and roxithromycin were 0.0156, 0.0078, and 0.03125 micrograms/ml, respectively. In vivo activities were assessed in a pulmonary infection model with Syrian golden hamsters. We evaluated the in vivo effects on reduction of viable M. pneumoniae cell counts and on reduction of microscopic and macroscopic histopathologies for azithromycin, erythromycin, and clarithromycin given at 10 mg/kg once daily for 1 and 3 days and given at 15 mg/kg twice daily for 2.5 and 5 days. Azithromycin was significantly more effective than erythromycin or clarithromycin in the same regimens. Especially at 10 mg/kg once daily for 1 day, only azithromycin was significantly effective in the reduction of viable M. pneumoniae cells and histopathologies. These results show that azithromycin is more efficacious than the other drugs tested against M. pneumoniae pneumonia in hamsters. These data suggest that clinical studies of macrolides in human patients are warranted.
Antimicrobial Agents and Chemotherapy 05/1994; 38(4):790-8. · 4.84 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: A new method for determining the MICs for Aspergillus species with slant-shaking incubation is described. The method was rapid (24 h), produced sharp visual end points, and showed high reproducibility. Additionally, MICs measured by this method correlated well with, as well as were two- to sixfold lower than, those by a reference method.
Journal of Clinical Microbiology 05/1993; 31(4):1009-12. · 4.15 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: No data on the genetic analysis of penicillin-resistant Streptococcus pneumoniae (PRP) in Japan has been reported. The SmaI restriction endonuclease digested patterns of chromosomal DNAs from 15 PRP serotyped 23F isolated in Japan were analyzed by pulsed-field gel electrophoresis (PFGE). The isolates were genetically heterogeneous and seven different PFGE patterns were identified. Nine strains were also resistant to erythromycin and tetracycline. Four strains revealed resistance to ceftriaxone. The PFGE patterns of some strains isolated in Nagasaki University Hospital were identical to each other and closely resembled those of isolates from three different areas of Japan. These results indicate a need for additional studies by PFGE to determine the possibility of clonal spread in Japan.
Chemotherapy 43(4):232-8. · 1.82 Impact Factor
