The in vitro susceptibilities of 74 clinical isolates of Candida from AIDS patients to 5 antifungal agents (amphotericin B, flucytosine, miconazole, fluconazole and itraconazole) were studied, in comparison with those of 100 stock cultures of Candida albicans, using the Frozen Plate for antifungal susceptibility testing. This testing kit was designed in accordance with the proposed reference technique of the Japanese Society for Medical Mycology. The clinical isolates from fluconazole treated patients were investigated to determine correlations between in vitro susceptibilities to 5 antifungal drugs and clinical responses to antifungal chemotherapy. The Frozen Plate yielded a relatively narrow range of MICs (0.12 to 2 βg/ml) for amphotericin B, but broaderMIC ranges were seen for luconazole (≤0.12 to >64 βg/ml), itraconazole (≤0.016 to>8βg/ml), miconazole (≤0.06 to 2βg/ml) and flucytosine (≤0.12 to 8βg/ml). A similar MIC distribution was observed for stock cultures of C. albicans. Among clinical isolates of Candida spp. there were several with low susceptibility or resistance to one or all three of the azole drugs. There was a good correlation between the in vitro fluconazole-susceptibility of clinical isolates from patients treated with this antifungal drug and their clinical outcome. Our results suggest the potential value of the Frozen Plate as a convenient and useful kit for testing the susceptibilities of yeast organisms.

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We determined the susceptibility of low level (Prevotella intermedia MA1) and high level (P. intermedia MA1-V2) β-lactamase-producers to β-lactam antibiotics and the substrate profile of β-lactamase from these organisms. Twenty-eight β-lactam antibiotics were used. MICs of four penicillins, 12 cephalosporins and two oral cephems for P. intermedia MA1-V2 were ≥128μg/ml, and β-lactamase activity from this organism against these drugs was ≥0.122 units of protein per mg. In this organism the MIC value of β-lactams paralleled the β-lactamase activity to substrate these drugs. Km and V_max values of MA1-V2 β-lactamase against these drugs were 6.3-2, 141.7μmol and 0.03-10.21μmol/min/mg of protein, respectively. However, it seems that enzyme activity and affinity of the substrate are not associated with the MIC at all. This enzyme hydrolyzed oxyiminocephalosporins, so we concluded that the enzyme is oxyiminocephalosporinase. As cefoxitin, cefmetazole, cefbuperazon, latamoxef and imipenem inhibited the β-lactamase activity against substrate cefazolin, these drugs were stable to β-lactamase producing MA1-V2.β-Lactamase inhibitors (clavulanic acid, sulbactam and tazobactam) inhibited the activity of β-lactamase against substrate cefazolin. MICe of the β-lactam antibiotic used against MA1 were very low, and β-lactamase from this strain weakly hydrolyzed 17 substrate drugs. These results suggest that MA1-V2 β-lactamase hydrolyzes broad-spectrum β-lactam antibiotics except for cefsulodin, cephamycins, imipenem, latamoxef and aztreonam, and that this enzyme is closely associated with the cross-resistance or high level β-lactam antibiotic resistance of P. intermedia MA1-V2.

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We investigated the combined effect of sparfloxacin (SPFX) and fosfomacin (FOM) against Pseudomonas aeruginosa and MRSA in vitro and in vivo. The in vitro combined effect of SPFX and FOM was examined by the checkerboard method and analyzed using time-killing curves. The FIC index of this combination against 22 strains of P. aeruginosa and 32 strains of MRSA ranged from 0.253-0.625 and 0.127-1.0, respectively. From the time-killing experiments, the effect of SPFX and FOM on 4 strains of P. aeruginosa and 3 strains of MRSA was shown to be synergistic. The effect of SPFX and FOM in vivo against quinolone-resistant P. aeruginosa KP-62 and MRSA K-1 was examined in ascending pyelonephritis or systemic infections in leukopenic mice. Both SPFX alone at a dose of 12.5 mg/kg and FOM alone at 3.13 mg/kg in the ascending pyelonephritis or systemic infection models with P. aeruginosa KP-62 and MRSA K-1 showed only a slight or no effect. However, the combined use of SPFX and FOM at the same dose levels showed remarkable synergistic effects, exhibiting 70% bacterial eradication in the kidney of ascending pyelonephritis mice, and a survival rate of 70% for P. aeruginosa KP-62 and 60% for MRSA K-1 in systemic infections. The uptake of ¹⁴C-SPFX by P. aeruginosa and the MRSA after concurrent incubation with FOM or 2-hour preincubation with FOM was higher than without FOM. These results suggest that the combined use of SPFX and FOM may be clinically useful in the treatment of P. aeruginosa and MRSA infections.

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We found that long-term treatment with clarithromycin (CAM) prolonged the survival time of patients with inoperable primary non-small-cell lung cancer. In the present study, we examined peripheral blood mononuclear cells for changes in the expression of mRNA IL-12 subunit p 35 and p 40 by RT-PCR. The study included 11 patients with inoperable primary non-small-cell lung cancer. They received basic therapy consisting of chemotherapy, radiotherapy or both. After discharge, 9 patients were assigned to CAM treatment and 2 were assigned to a non-CAM group as controls. The expression of IL-12 subunit p 40 mRNA was elevated 3 months after the initiation of CAM treatment. These results indicate that CAM may exhibit anti-tumor effect by inducing the expression of IL-12 in peripheral blood mononuclear cells.

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BO-2727 New Formulation, a new injectable carbapenem antibiotic, was administered to 24 patients with complicated urinary tract infections (UTI). Of the 24 patients, 21 were assessed according to the criteria proposed by the Japanese UTI Committee. The overall clinical efficacy rate was 76.2%(excellent response in 7 patients, moderate in 9 and poor in 5). Bacteriologicaly, 28 (90.3%) of 31 strains isolated were eradicated. As for side effects, loose stools were observed in one patient; an increase in basophilic leukocytes, in one patient; and liver function test abnormalities, in 3 patients.

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The effects of macrolide antibiotics which do not originate from their antibacterial action have recently been elucidated. We therefore administered clarithromycin (CAM) to HIV-infected patients and assessed their clinical course. Four HIV-infected patients whose CD 4 lymphocyte count was below 100/μl in spite of anti-HIV therapy and who had not developed AIDS before administration of CAM were enrolled in this study. The patients were treated with CAM 200 mg once daily. Two of the four patients developed AIDS and one of these two died of AIDS after long-term treatment with CAM. The average survival period (CD 4<100/μl) was 41.8 months, and the period of treatment with CAM averaged 25.3 months as of August 1996. CD4 lymphocyte counts increased in the three patients between 5 and 10 months after the start of administration of CAM. The serum concentration of/β-microglobulin did not change in the surviving patients, but it increased in the patient who died. Serum p-24 antigen could no longer be detected in one patient, and this patient's CD 4 lymphocyte count increased twice after treatment with CAM. The serum concentration of tumor necrosis factor-α(TNF-α), which stimulates replication of HIV, decreased in the surviving patients treated with CAM.These results suggest that long-term treatment with CAM may be effective in HIV-infected patients with advanced disease and that CAM may modify the serum concentration of TNF-α in patients with HIV infection.

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