The susceptibilitieds of 59 clinical isolates of oral streptococci and 21 of anaerobic bacteria were determined by a new method, the E Test (AB BIODISK, Solona, Sweden), and were compared with the MICs for these organisms obtained by the referece agar dilution method. The MIC values for oral streptococci obtained by both methods were in agreement. The E Test MICs for Peptostreptococcus micros and Prevotella intermedia were within 1 dilution and 2 dilution of the agar dilution MICs respectively. The E Test is easy, and offers the laboratory a reliable method for susceptibility testing for oral streptococci and anaerobic bacteria.

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The present study was designed to measure the penetration of fleroxacin (FLRX) into various tissues of New Zealand white male rabbits whose mandibles were experimentally infected with a combination of Streptococcus milleri and Bacteroides fragilis. When 20 mg of FLRXper kg was orally administered to the infected rabbits and normal rabbits, the T_max values of FLRX in the serum were 1.47 h in the infected group and 1.28 h in the normal group, while the C_max values were 3.55 μg/ml and 3.23 μg/ml, respectively. In various tissues of the infected group, T_max values were 1.62 to 2.14 h and the C_max values were 2.01 to 6.21 μg/g. In particular, higher levels of transfer were observed in the submandibular lymph node, parotid gland and submandibular gland. The ratios of C_max to the serum level in the maxilla and mandible were approximately 57 % and 61 %, respectively. The C_max of FLRX in the pus obtained from the infected site was 3.08 μg/ml, which was 90 % of the serum level. FLRX showed sufficient concentration in the various oral tissues, and is fully expected to have an excellent clinical effect in the treatment of infectious diseases.

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The effects of vancomycin (VCM) and other antibiotics, both alone and in combination, against colonies of methicillin-resistant Staphylococcus aureus (MRSA) in cotton suture were investigated. The simultaneous combination of VCM and arbekacin (ABK), VCM and flomoxef (FMOX), VCM and sulfamethoxazole-trimethoprim (ST), and VCM and rifampicin (RFP) showed marked bactericidal activity. Of these four combinations, VCM and ABK showed the greatest bactericidal activity. When VCM in combination was given with a time lag, more favourable results were obtained when other antibiotics were given first than when VCM was given first. An animal study employing a rat model was conducted on the pharmacokinetics of ABK and VCM, influences of the drugs on the kidney, and the possibility of alleviation of renal toxicity, supposing a 3-day combination therapy of VCM +ABK for treatment of MRSA infection followed by 5-day therapy with either of the two drugs. The renal toxicity was apparently lower in the ABK group than in the VCM group, and recovery of the renal condition was also more favourable in ABK group. Such renal toxicity as was shown in the study was alleviated when fosfomicin was combined, while the renal toxicity worsened and some deaths occurred when piperacillin was combined.

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For 36 patients undergoing cholecystectomy, a single 2g dose of ceftriaxone (CTRX) was administered by intravenous infusion prior to surgery. Following surgery, for each tissue sample obtained from the collum, corpus, and fundus of each surgically resected gallbladder, the tissue concentration of CTRX was individually determined. Additionally, ten pathological factors were selected, and the relation ship between pathological findings in each tissue sample and the effects exerted by the pathological factors on tissue concentration and tissue penetration of CTRX were investigated by multiple regression analysis. Pathological factors which were considered to affect the tissue concentration in the collum were local accumulation of inflammatory cells, the presence or absence of erosion, and the extent of wall hypertrophy. In the fundus, factors which were found to influence tissue concentration were the presence or absence of acute inflammation, the presence or absence of erosion, and the extent of wall hypertrophy. In the corpus, no significant relationship was observed between the tissue concentration of CTRX and the pathological factors. Penetration of CTRX into gallbladder tissue was extremely good, and the wet weight concentrations of CTRX in the collum, corpus, and fundus were high at 279.6μg/g, 239.1μg/g, and 265.8μg/g, respectively. Following administration of CTRX, no adverse reactions, no abnormalities in laboratory data, and no postoperative infections were observed.

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A high concentration of parenteral fluoroquinolone, T-3762 was used to study its antimicrobial activity against Pseudomonas aeruginosa and Escherichia coli because of the high peak plasma concentration in human healthy volunteers. Once 5-minute exposure of T-3762 with bacteria resulted in a rapid decrease in the number of viable cells and suppression of growth during 5-120 min incubation in drug-free broth, while β-lactams did not. It should be noted that parenteral fluoroquinolones may be more active at high concentrations and in a short time.

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