We investigated the susceptibility to norfloxacin (NFLX), and serotype and phage type of clinical isolates of Pseudomonas aeruginosa. From NFLX sensitive strains we obtained NFLX-resistant mutants and demonstrated sodium dodecyl sulfate-polyacrylamide gel electrophoresis of outer membrane proteins of those strains.
1) Since 1986, NFLX-resistant P. aeruginosa strains have been increasing in Gunma University Hospital parallel with increasing use of NFLX.
2) Serotypes of both NFLX-resistant and -sensitive strains were B, (and non typable, and their phage types mostly Hh8 (non-typable). There was no suspicion of nosocomial infection of NFLX resistant Pseudomonas aeruginosa.
3) Four major types (nfx A, DNA gyrase type mutant; nfx B, nfx C and nal B, permeability type mutants) of NFLX-resistant mutants were obtained from drug-sensitive clinical isolates. Nfx C type mutants with concomitant IPM resistance were isolated easily, but the isolation frequency was similar to that of others.
4) Outer membrane proteins of NFLX-sensitive strains from clinical isolates showed a little difference between each other.
Nfx A type mutation did not show any change in outer membrane proteins. In nfx B type mutants, new 50 to 52 KD outer membrane proteins were detected. In nal B type new 48 KD protein appeared. Nfx C type mutants showed various patterns of appearance and disappearance of outer membrane proteins.

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To investigate yearly trends in resistance to new quinolones and multiple drug-regimeus we determined the MICs of new quinolones, penicillins and cephems against 400 isolates of five Grampositive cocci (200 each isolated in 1985 and 1988), and obrained the following results:
1. In 1988 a marked increase in new quinolone resistant strains was found in Staphylococcus aureus and Enterococcus faecium isolates, and some new quinolone resistant strains in Enterococcus faecalisisolates.
2. New quinolone resistant S. aureus isolates were mostly MRSA-resistant strains, but new quinolone resistant MSSA isolates also showed a tendency to increase.
3. New quinolone resistant strains of E. faecium were found against the four major compounds NFLX, OFLX, ENX and CPFX. In 1985, new quinolone resistance in S. aureus isolates was found mostly against NFLX and ENX, but in 1988 MRSA isolates showed an increase in resistance against all four quinolones.
4. In 1988, MIC distribution of new quinolones against Streptococcus pyogenes and Streptococcus pneumoniae was 1-2 tubes (2-4 fold) higher than in 1985.
5. Penicillin-resistance in E. faecium isolates increased.
6. In 1988 S. pneumoniae strains with low β-lactam susceptibility were sometimes found.

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We determinend MICs against 350 isolates of Escherichia coli, Klebsfrila pneumoniase, Proteus mirabilis and Haemophilus influenzae (four species of “4 major Gram negative bacilli”) collected in 1985 and 1988 the and results were as follow:
1. New quinolone resistant strains were shown in E. coli and K. pneumoniae. New quinolone resistant E. coli strains were isolated from female patients with auto-infections of the urinary tract, suggesting that new quinolone resistant strains are increasing in the setting of community acquired infections.
2. Cephem-resistant E. coli (CREC) have been increasing, and an increase in multidrug-resistant E. coli is a cause for concerne.
3. No new quinolone resistant strains of P. mirabilis or H. influenzae were found in.
4. No yearly increase in, β-lactamase producing H. influenzae was identified.

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We determined the MICs against 400 isolates of Citrobacter freundii, Enterobacter cloacae, Serratia marcescens, Proteus vulgaris and Morganella moraganii (five species of “weakly toxic Gram-negative bacilli”) collected in 1985 and 1988 the results were as follow:
1. Species Resistance to new quinolones appeared or increased in C. freundii, E. cloacae, P. vulgaris and M. morganii. Most of these new quinolone resistant strains were isolated from urine of inpatients, but resistant strains from other sources were also encountered, suggesting a rapid increase in “weakly toxic Gram-negative bacilli” resistant to new quinolones. As the resistance of these strains was mostly high there is reason fear to the development of multidrug-resistance.
2. More new quinolone resistant strains of Serratia marcescens were isolated in 1988 than in 1985, and more than half of the isolates from urine of in patients were resistant and the ratio of highly resistant strains also increased.

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We determined the MICs against 100 isolates of Psuriotnonas acruginosa collected in 1985 and 1988 the results were as follow:
1. P. aeruginosa isolates resistant to new quinolones markedly increased in 1988, those of urinary origin in patients accounted for more than half of the isolates and those from sputum also increased. In addition, the ratio of highly resistant strains was high.
2. The number to ceftazidime-resistant P. aeruginosa strains in clinical isolates increased between 1985 and 1988, and exceeded 50% of isolates from urine of in patients, but the ratio of highly resistant strains was relativery low.
3. Strains of P. aeruginosa resistant to imipenem were found in isolates in 1988.
4. In 1985 we found only 10 drug resistant patterns in P. aeruginosa isolates whereas in 1988 there were 21 suggesting an increase in multidrug-resistance of P. aeruginosa.

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We compared the in vitro antifungal activity of amphotericin B (AMPH) with those of flucytosine (5-FC), miconazole (MCZ) and fluconazole (FCZ) against recent clinical isolates, including 50 strains of Candida albicans, 20 strains of Aspergillus fumigatus and 13 strains of Trichosporon beigelii. Of these, 5% to 10% were resistant to 5-FC, but no strains resistant to other antimycotics were observed. Although AMPH still showed the highest activity against A. fumigatus and C. albicans, T. beigelii was more sensitive to MCZ than AMPH. In the drug sensitivity test for AMPH, sensitivity test medium (KDA) was superior to other media. Although MIC values of 5-FC and AMPH correlated with the in vivo efficacy, a 50% turbidimetric endpoint (50% inhibitory concentration of growth; IC₅₀ values determined by broth microdilution assay) was found to much correlate closely with the in vivo efficacy of FCZ. Problems in standardizing a susceptibility test for antimycotics including standard strain and media are discussed.

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We evaluated the antibacterial effect of OPC-7251, a new fluoroquinolone derivative, in acne patients. Three groups of patients received topical application of 1% OPC-7251 cream, 0.5% OPC-7251 cream or the cream base to their face in a double-blind half-sided comparative manner. One side of the face of each patient was regarded as one case. Each preparation was simply applied to the face twice daily, morning and evening. Clinical bacterial samples were isolated by expressing acne lesions with a comedo extractor and cultured on modified GAM agar plates. The number of microorganisms in each sample was then semi-quantitatively determined by counting the number of colonies developing. Data were obtained for bacteriological analysis from 130 cases treated with OPC-7251 cream or the base: 45 cases with 1% OPC-7251 cream, 42 cases with 0.5% OPC-7251 cream and 43 cases with the base. Of the identified microorganisms, the most frequent was Propionibacterium acnes in 117 cases (90.0%), followed by Staphylococcus epidermidis in 34 cases (26.2%). Propionibacterium spp. including P. acnes, were identified in the samples isolated from 126 cases (96.9%). A comparison of pre- and post-treatment counts of all isolated microorganisms and P. acnes in each group indicated a significant decrease in the 1% and 0.5% OPC-7251 cream group compared with the decrease in the base group. However, no significant difference was observed between the 1% and 0.5% OPC-7251 cream groups. Examination of the susceptibility of P. acnes isolated before and after treatment revealed that the bacterium did not develop resistance to OPC-7251.

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Based on clinical findings and animal studies showing changes in intestinal bacterial flora in rats, we have previously reported the usefulness of colon preparation for preventing postoperative infection in colon surgery. In this study, we selected effective microbial agents forcolon preparation before surgery, and determined adequate dosages and treatment duration from a new point of view, namely, in addition to performing a basic study on changes in major intestinal bacterial flora, we serially measured levels of various antimicrobial agents in intestinal contents in normal rats fed with elemental diet and in rats with a stenosis prepared as an ileus model. In the normal rats, metronidazole (MTN) when given orally together with kanamycin (KM) for 4 consecutive dayswas first detected in intestinal contents on daytreatment, and its levels in the cecum andrectum were 9.0 and 3.5 μg/g. This concomitant treatment markedly reduced major intestinal flora. When the animals were percutaneously treated with piperacillin (PIPC), cefmetazole (CMZ), cefoperazone (CPZ), or cefoperazone (CPZ) +sulbactam (SBT), peak levels appeared 8 h in the cecum and 24h in the rectum after administration of PIPC, and the other agents peaked 24 h after administration. Peak levels in the cecum and rectum were 430 and 141 μg/g of PIPC, 753 and 1, 025 peg of CMZ, 66 and 978 μg/g of CPZ, and 89 and 790 μg/g of SBT. When levels peaked intestinal bacterial flora in the groups percutaneously treated with CMZ and CPZ+SBT showed the same effect as that in the group given KM+MTN orally. In the rats with stenosis prepared as a model of patients without sufficient preoperative preparation, including oral treatment with antimicrobial agents, due to an occlusive condition, the levels of penetration of CMZ and CPZ+SBT were determined because these agents were thought to sufficiently penetrate into intestinal contents in the normal rats. Although CMZ and CPZ+SBT peaked only 36 h after administration, the decrease in intestinal bacterial flora was the same as that seen in the normal rats. These results suggest that oral treatment with KM+ MTN for 4 consecutive days, and percutaneous treatment with CMZ or CPZ+SBT at 24 h before operation serve as an effective preoperative colon preparation to prevent infection following colon surgery, and that systemic treatment with CMZ or CPZ+ SBT 36 h before operation is an effective bacteriological preparation, even if an occlusive condition prevents mechanical preparation.

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