Susceptibility of anaerobic bacteria to five antimicrobial agents and demonstration of resistance of Bacteroides fragilis to clindamycin.

Minimal inhibitory concentrations (MICs) of penicillin G, cefamandole, tetracycline, clindamycin and metronidazole were determined against 42 isolates of anaerobic bacteria. metronidazole was the most active antimicrobial agent against all anaerobic bacteria tested and especially against the Bacteroides fragilis group (MICs for all strains ranged from less than equal to 0.5 to 4 micrograms/ml). Seventeen out of 20 strains of B. fragilis subsp. fragilis were resistant to clindamycin with an MIC ranging between 8 and 128 micrograms/ml. Such resistance of B. fragilis strains should alarm physicians, after the widespread use of clindamycin, since this group of organisms is the most frequently isolated from anaerobic infections.

Plasmid determined drug resistance in clinically isolated Escherichia coli.

The results of a survey for the presence of R plasmids in 100 clinically isolated strains of Escherichia coli are presented. Sixty-nine per cent of the strains were resistant to at least one of the antimicrobial agents tested and 63.7% of the resistant strains transferred all or part of their resistance genes to Escherichia coli k 12.

Serological evidence of human leptospirosis in northern Greece.

a) 1069 human blood samples were tested for the presence of C. F. antibodies to leptospirae. 98 of these sera were from patients suffering from Weil's syndrome. 13 out of 98 patients were found to be suffering from leptospirosis; one of these died. 460 sera were from patients with febrile (acute) illness of unknown origin and 511 sera from patients with respiratory disease (especially "influenza like disease"). None of these patients was found to be suffering from leptospirosis. b) 191 human sera from healthy people at risk to leptospiral infection were examined by microscopic agglutination test (MAT). A high percentage (14.1%) was found to have antibodies against one or two leptospiral serogroups. The results obtained suggest that the incidence of leptospiral infections in humans in Northern Greece is higher than previously reported and the predominant serogroups were found to be Icterohaemorrhagiae followed by Autumnalis and Canicola.

In vitro comparison of kanamycin, kanendomycin, gentamicin, amikacin, sisomicin, and dibekacin against 200 strains of Pseudomonas aeruginosa.

The antimicrobial activity of kanamycin, kanendomycin, gentamicin, amikacin, sisomicin, and dibekacin against 200 strains of Pseudomonas aeruginosa was compared. Dibekacin was found to be the most active against the tested organisms, whereas the other aminoglycoside antibiotics fell in the following order of diminishing antibacterial potency: amikacin, sisomicin, gentamicin, kanendomycin, and kanamycin. Seven strains showed high-level resistance to gentamicin (minimal inhibitory concentration, 400 mug/ml), and two of them were also resistant to amikacin and sisomicin (minimal inhibitory concentration, 75 mug/ml). The minimal inhibitory concentration of dibekacin for these seven strains was 0.625 mug/ml.

Comparative study of the prevalence of mycoplasma in males with non specific urethritis.

Three groups of males were examined for the study of Mycoplasma in the aetiology of Non-specific Urethritis. From a group of 120 men suffering from N.S.U. (group I) have been isolated from the genital tract "large-colony" and T-strain mycoplasma in proportion 22.5% and 68.3% respectively. Socially this group represent the lower classes of the population. From another group of 165 male students suffering also from N.S.U. (group II) have been isolated from the genital tract "large-colony" and T-strain mycoplasma in proportion 25.4% and 58.1% respectively. This group was of higher social and hygienic standards. In contrast in a control group of 70 medical students without urethritis the range was for the "large-colony" 8.5% only and for the T-strain 21.4%. Socially, this group corresponded closely to the Group II. In this study a significant association of T-strain mycoplasma with N.S.U. has been found. Urethral specimens were obtained from all the men by the same method. No statistically significant difference in the isolation rate of Mycoplasma was seen, between Group I which represents a relatively low social and hygienic level and Group II which represents higher social and hygienic standards. It is interesting to note that the percentage of control healthy group (group III) yielding T-strain mycoplasma was lower and no similar to that recorded in previous investigations.