To clarify the epidemiology and the resistant mechanisms of ampicillin-resistant Haemophilus influenzae in Japan we conducted a multicenter study involving 11 hospitals. The microbiological studies were done in the Department of Microbiology, Gunma University.
Ampicillin-resistance was considered present when the H. influenzae were β-lactamase producing or required an MIC equal or greater than 1.56μg/ml at 10⁶ CFU/ml.
Ampicillin-resistant H. influenzae were first isolated in Tokyo and Chiba 1975, and in Sendai 1976. Subsequently similar organisms were isolated in other parts of Japan. The frequency of isolation of ampicillin-resistant H. influenzae from clinical specimens ranged between 5.9-21% with a mean of 12.4%. The general trend was one of an increasing frequency year after year.
In the present study the highest MIC was 50μg/ml and the peak was at 6.25μg/ml. The β-lactamase activity ranged from 0.14 to 1.56 units (mean±SD=0.6±0.36). The types of β-lactamase isolated in this study belonged to penicillinase type I using MITSUHASHI's classification or TEM type by RICHMOND'S classification.Sensitivity to chloramphenicol was determined in 92 β-lactamase-producing strains of H. influenzae. Four (4.3%) strains were found to be resistant.
Experimental conjugation was done in 6 strains of β-lactamase-producing H. influenzae resistant to ampicillin and tetracycline. Ampicillin resistant factors were successfully transferred to E. coli in 2 strains. However, resistance to tetracycline was not transferable.
The results of this first multicenter study on the epidemiology of ampicillin-resistant H. influenzae in Japan indicated that, like in other countries, the problem is on the increase. It is important therefore that such studies should be continued.

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Susceptibility test of Chlamydia trachomatis to antimicrobial agents was done by using cell culture method. C. trachomatis used were from nongonococcal urethritis andpassaged less than 3 times. Antimicrobials were added to growth medium after C. trachomatis was inoculated onto monolayers of McCoy cells, centrifuged for one hour and incubated for one hour. Chlamydial inclusions were detected by both Giemsa staining and MicroTrak technique. The influence of inoculum size of C. frachomatis on their susceptibilities was not appeared in all 4 antimicrobial agents utilized; doxycycline (DOXY), midecamycin (MDM), norfloxacin (NFLX) and ampicillin (ABPC). The ranges of minimum inhibitory concentrations against 5 clinical strains were ≤0.03μg/ml for DOXY, 0.125-0.25μg/ml for MDM, 16μg/ml for NFLX and 0.25-0.5μg/ml for ABPC using Giemsa staining. When using MicroTrak technique inclusions of C. trachomatis were detected at 2 to 3 times higher concentrations than those with Giemsa staining: 0.06-0.125μg/ml for DOXY, 0.125-0.5μg/ml for MDM and 16-32μg/ml for NFLX. However, for ABPC inclusions-likesubstances were detected even at a concentration of 64μg/ml, a highest concentration used. MicroTrak technique seemed to be superior to Giemsa staining because inclusions damaged by antimicrobial agents were also detectable with MicroTrak technique and that produced more appropriate susceptibilities of C. trachomatis.

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We have studies on the penetration of ten kinds of antibiotics into human polymorphonuclear leukocytes (PMNs) by the method of High Performance Liquid Chromatography (HPLC).
The penetration into PMNs of some of the beta-lactam antibiotics, such as ampicillin, piperacillin, cefazolin, and ceftizoxime was poor whereas the penetration of AC-1370, a new cephem antibiotic was somewhat superior to cephems above mentioned (C/E=1.18). The intracellular concentrations of these antibiotics remained much lower than the extracellular concentrations (C/E<0.5).
Rifampicin and isoniazid attained slightly higher intracellular antibiotic concentration (C/E=1.27 and 1.32, respectively). The intracellular concentration of lincomycin was approximately three times higher than the extracellular concentration (C/E=2.65).
In contrast, the intracellular concentration of clindamycin was ten times higher than the extracellular concentration (C/E=12.70). The C/E ratio, however, gradually decreased after reaching a maximum value at 15 to 30 minutes, but that of rifampicin kept in almost same level in each time during two hours. The intracellular concentration of ofloxacin was eight times greater than the extracellular concentration (C/E=8.10).
The C/E ratios of antibiotics obtained in our study were very similar to the results reported by the radioisotope technique.

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Pharmacokinetic analysis of placental transfer of latamoxef (LMOX) was performed using a modified compartment model.
Concentration of LMOX was examined in maternal serum, umbilical cord serum and amniotic fluid after a single intravenous administration of 2.0g dose.
Data obtained were used for this study.
Maternal serum concentration was analyzed by a two-compartment model.
Concentration in umbilical cord serum and amniotic fluid were analyzed using the parameters obtained in the analysis of the maternal serum concentration as constants.
1. The peak level of LMOX in maternal serum was 217.4μg/ml and half life of the a-phase was 1.74 hours.
2.The concentration in umbilical cord serum was rapidly increased and reached a peak of 35.3μg/ml at 1.55 hours after the administration.
3.The concentration in amniotic fluid was slowly increased and reached a peak of 28.2μg/ml at 6.92 hours.It was decreased very slowly, but it still remained 17.3μg/ml at 16 hours.
4.The absolute transfer ratio calculated with obtained parameters were 2.30% and 0.38% for the umbilical cord serum and the amniotic fluid respectively.

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Combination therapy of cefmenoxime (CMX) and aminoglycosides (TOB, AMK, GM) was evaluated in 52 cases with infections accompanied by hematological diseases (leukemia, aplastic anemia etc.).
Clinical responses among 41 evaluable cases out of 52 were excellent in 8, good in 13, fairin 10, and overall effective rate was 51.2%.
The efficacy of this therapy decreased proportionally with the reduction of the number of peripheral mature granulocyte count, but 12 out of 29 cases with granulocyte counts less than 500/μl including 10 cases with 0/μl still responded (41.3%).
The effective rate was 30% even in the definite immunocompromized hosts, namely in the terminal stages in hematological diseases. Serum concentrations of CMX and aminoglycosides were far above minimum inhibitory concentrations of isolated organisms.
No significant side effects were observed in this combination therapy except for eruption in a case and slight renal dysfunction in 2 cases.
These results indicate that the combination therapy of CMX and aminoglycosides are useful for the treatment of severe infections complicated wit hematologicaldiseases.

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The clinical efficacy of doxycycline (DOXY) in Chlamydia trachomatis-positive urogenital infections was investigated. Of 204 cases, 106 cultures were found to be positive for C. trachomatis before treatment and of these, 96 cases were microbiologically and clinically evaluable. Side effects were monitored in 191 cases. Most of the cases were given 100mg DOXY twice daily for 7 to 14 days. C. trachomatis was not isolated in more than 90% of the cases on day 7 and in 100% of the cases on day 14 of treatment. When MicroTrak technique (direct smear test) was employed, however, C. trachomatis became detectable on days 3 and 7 but not on day 14. C. trachomatis tended to be eradicated later in cervicitis and gonococcal urethritis than in Chlamydial urethritis. When C. trachomatis was identified by culture, the disappearance of subjective symptoms paralleled eradication of the pathogen. Polymorphonuclear cells (PMN) in direct smear and first-voided urine as well as macroscopic discharge were also evaluated. Discharge as a macroscopic finding disappeared at the same time as C. trachomatis following administration of the antibiotic. However, PMN were cleared in most cases approximately one week later than the macroscopic discharge. The overall clinical efficacy rate of DOXY as assessed by eradication of C. trachomatis and elimination of subjective symptoms and discharge (including PMN) was over 90% on day 14 for each of these parameters. Side effects, all gastrointestinal, were noted in 5 cases (2.6%). In this investigation, DOXY was microbiologically and clinically effective in the treatment of Chlamydial infections.

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