Tobramycin (factor 6 of the nebramycin complex) is a new aminoglycoside antibiotic isolated from Streptomyces tenebrarius which is active against S. aureus, Enterobacteriaceae, and Pseudomonas aeruginosa. Susceptibility to tobramycin of 96 strains of P. aeruginosa, including 45 recent isolates from blood, was studied by using agar and broth dilution methods. The minimum inhibitory concentration (MIC) for 83 of 96 strains was 3.12 mug/ml or lower in Mueller Hinton agar; MIC values were two to eight times lower in Mueller Hinton broth tests. Agar dilution MIC values were generally lower than those obtained in parallel tests with gentamicin. Killing curves obtained from serial sampling of broth cultures showed a 100- to 10,000-fold decline in viability of log-phase organisms within 30 min of exposure to the drug. Two-dimensional agar dilution tests with carbenicillin and tobramycin with 79 strains showed additive or synergistic effects; no antagonism was documented. Seventy-eight of 79 strains were inhibited by a combination of 50 mug of carbenicillin per ml and 1.56 mug of tobramycin per ml, blood levels which seem attainable in man. Tobramycin appears to be a potent, rapidly bactericidal antibiotic against P. aeruginosa and merits clinical evaluation.

Agar↗

PubMed1971

Post-transfusion cytomegaloviremia and persistence of cytomegalovirus in blood.

Cytomegaloviremia was documented in seven patients. Three patients were renal transplant recipients and two were liver transplant recipients. One was a postcardiac surgery patient, and one had acute myelogenous leukemia. The transplant patients had received only banked blood or fresh frozen plasma and developed evidence of infection about 1 month after surgery. Illness varied from no apparent signs to fever alone, fever and a morbilliform rash, hepatitis and an infectious mononucleosis syndrome. The virus was isolated from the blood erythrocyte layer, the leukocyte layer, and the plasma and serum, in that order of frequency. In vitro studies demonstrated persistence of inoculated cytomegalovirus in the presence of erythrocytes (and tissue culture media) for up to 21 days. In whole blood under banking conditions, inoculated virus was recovered after 28 days and, in fresh frozen plasma, after 97 days.

Journal Article↗

PubMed1971