The antimicrobial activity of ciprofloxacin against Legionella species and the treatment of experimental Legionella pneumonia in guinea pigs.

The antimicrobial activity of ciprofloxacin was tested against 15 standard reference strains, and 37 clinical and environmental strains of Legionella pneumophila by an agar dilution method, using a new growth medium (B-SYE agar) which we devised. The minimal inhibitory concentrations of ciprofloxacin were found to be inoculum dependent, and ranged from 0.02 to 0.06 mg/l at 10(4) cfu inoculum and 0.02 by 0.125 mg/l at 10(6) cfu inoculum. The most potent antibacterial activity was shown by rifampicin, followed by ofloxacin, ciprofloxacin, enoxacin, norfloxacin, erythromycin and pipemidic acid in that order. The therapeutic efficacy of ciprofloxacin in experimental guinea pig pneumonia due to L. pneumophila was fairly good with a survival rate of 80%. From other data of ours, its effectiveness in experimental pneumonia was equal to or greater than that of erythromycin. Further studies would be appropriate to investigate the possibility of using ciprofloxacin for the treatment of human L. pneumophila infection.

[The concomitant effect of a newly developed gamma-globulin preparation (SM-4300) with some antibiotics on severe bacterial infections].

Twenty-six patients with bacterial infections, mainly respiratory infections, were treated with newly developed gamma-globulin preparation (SM-4300), as a combination therapy with some antibiotics. The result was as follows. Clinical effects of 18 cases evaluated were excellent in 1 case (5.6%), good in 10 (55.6%), fair in 4 (22.2%) and poor in 3 (16.7%). No remarkable adverse reactions and abnormal value in laboratory data due to administration of SM-4300 were observed. Significant changes of complement system before and after administration of SM-4300 were not observed. It was considered that SM-4300 was effective as a combination therapy with some antibiotics for the treatment of severe or refractory bacterial infections.

Susceptibility of Legionella pneumophila to ofloxacin in vitro and in experimental Legionella pneumonia in guinea pigs.

The antimicrobial activity of ofloxacin was tested against 15 standard strains and 37 clinical and environmental strains of Legionella pneumophila by agar dilution susceptibility studies with a new growth medium. The ofloxacin MICs were inoculum dependent and ranged from 0.03 to 0.125 microgram/ml. The antibacterial activities of other agents tested relative to ofloxacin were rifampin greater than ofloxacin greater than josamycin greater than pipemidic acid. Ofloxacin, at concentrations equal to or greater than 0.05 microgram/ml, inhibited the growth of L. pneumophila grown in human monocytes. The therapeutic efficacy of ofloxacin in experimental guinea pig L. pneumophila pneumonia was greater than that observed with erythromycin or josamycin therapy; it was less effective than was rifampin. Ofloxacin was very active against intracellular L. pneumophila in these experiments and should be studied in the therapy of human Legionnaires disease.

[Clinical studies on TMS-19-Q.O tablet in respiratory tract infection].

A new macrolide antibiotic preparation, TMS-19-Q.O tablet, was used to investigate the efficacy in the treatment of patients with respiratory tract infection, and the results obtained were as follows: Three hundred and seven cases were included in this report, and overall efficacy rate was 76.2%. Especially high clinical effect (86.0%) was observed in the treatment of patients with pneumonia including mycoplasmal pneumonia. Bacteriological effect was 87.5% in 51 cases identified as single infection of Gram-positive cocci and was 48.0% in 34 cases Gram-negative rods infection. Side effects were observed in 11 cases (3.50%): gastrointestinal disorder in 8, eruption in 2 and other in 1. Abnormality in laboratory tests was observed in 23 cases, hepatic disorder in 13, renal disorder in 3 and other laboratory tests in 7. It was considered from the results of clinical and bacteriological efficacy in different dose study that dose of TMS-19-Q should be 600 mg.

Clinical complications of Mycoplasma pneumoniae disease--other organs.

Although self-limited respiratory tract infections caused by Mycoplasma pneumoniae are well recognized in children and young adults, respiratory involvements and hepatic dysfunction may occur. The frequency and clinical features of these complications were investigated. Experimental studies with regard to bacterial superinfection were also carried out. The test animals which were first infected with Mycoplasma pneumoniae and then with Staphylococcus aureus showed more extensive bacteriological and pathological changes than those infected with Staphylococcus aureus only. Liver biopsies performed on three human patients showed hepatic dysfunction and the histological findings were diagnosed as non-specific reactive hepatitis in each case.