It has been established that acute rheumatic fever and acute glomerulonephritis occur following antecedent group A streptococcal infection in upper respiratory tract, and the virulence of streptococci and host reactivity are very important factors for the developing of the complications. Moreover, several reports have indicated that hemolytic streptococci have been recovered from the cultures of throats of the subjects who are receiving antibiotic therapy. The present investgation was designed to demonstrate the recovery of beta hemolytic streptococci from swabs and tonsillar tissues in patients with chronic tonsillitis and the effect of antibiotic therapy on eradication of beta hemolytic streptococci.
The following in vitro studies were carried out using 23 strains of Klebsiella pneumoniae isolated from clinical materials in recent years: 1) The MIC of Cephalothin (CET) against K1. pneumoniae was determined by the agar dilution method. Then, the amount of 0.002ml of CET-inactivating substance, which is supposed to consist mainly of Cephalosporinase with the ability to inactivate 250, 000μg of CET/ml was added to each of surfaces of the plate which had previously been inoculated with test bacteria. After an overnighti ncubation at 37°C, the minimal concentration of CET at which no colony appeared was judged as “MBC”. As a result, it was found that the values of MIC and “MBC” were markedly affected by the number of inoculated bacteria. In the group with the undiluted culture of bacteria, the MIC was 25-50μg/ml in most of the strains and “MBC” was 400μg/ml or more in almost all of the strains; on the other hand, in the group with 10, 000 fold dilutions, MIC and “MBC” showed almost the same values, from 3.13 to 6.25μg/ ml in most of the strains. 2) The effects of the combined use of Gentamicin (GM) and CET were examined using agar plate inoculated with the undiluted culture of bacteria by the two-dimensional, two-fold dilution procedure. The combined use of GM and CET did not show such a significant difference between MIC and “MBC” as seen in the single use of CET. 3) The effects of the combined use of GM and CET on 20 strains of K 1. pneumoniae were examined by the agar dilution method. By the two-dimensional, two-fold dilution procedure of these drugs, the MIC of CET which was used in combination with a certain concentration of GM and the MIC of GM which was used in combination with a certain concentration of CET were examined. Then, the number of bacteria having these MICs was counted and shown in the chess-board. Our survey on the number of bacteria, which growth was inhibited by the various combinations of GM and CET, clearly demonstrated that the in vitro antibacterial effects of GM and CET upon K1. pneumoniae were synergistic. In addition, it was confirmed that the concentrations of both antibiotics needed to inhibit the growth of almost all of the strains correspond to the blood concentrations which are obtained by usual doses of these antibiotics.
Propionylmaridomycin (PMDM) is a new macrolide-series antibiotic developed by the Research Laboratories of the Takeda Chemical Ind. Ltd., in 1972. Pharmacological and bacteriological studies have shown this agent to have an antibacterial activity almost equal to that of kitasamycin (LM) both in vitro and in vivo. The study was carried out in order to compare the clinical effect of PMDM, by double blind method, in respiratory infectious diseases (bacterial pneumoniae, acute bacterial bronchitis, acute tonsillitis) with that of LM as the control; 29 patients with bacterial pneumoniae were treated by 1600mg of PMDM or LM daily for 2 weeks; 38 patients with acute bacterial bronchitis and 32 patients with acute tonsillitis were treated by daily dose of 1200mg of PMDM or LM for 1 week. The following results were obtained. 1) Improvement of main symptomes of bacterial pneumoniae was observed in 11 of 16 patients treated with PMDM (68.8%) and in 9 of 13 patients treated with LM (69.2%). Improvement of main symptoms of acute bacterial bronchitis was observed in 14 of 22 patients in PMDM group (63.6%) and in 11 of 16 patients in LM group (68.8%). Improvement of main symptomes of acute tonsillitis was observed in 9 of 14 patients in PMDM group (64.3%) and in 15 of 18 patients in LM group (88.9%). The clinical effect of both antibiotics showed no significant difference. 2) Gastrointestinal disturbance was main side effect and no severe side effects, such as fever, skin rash, anaemia, toxic hepatits were observed in both PMDM group and LM group.