Therapy of pulmonary nocardiosis in immunocompromised mice.

We compared the bactericidal efficacies of various antimicrobial agents and combinations thereof in experimentally induced Nocardia asteroides pneumonia in immunocompromised mice. Cortisone acetate treatment, which produced impaired cell-mediated immune function, was followed by nasal inoculation of 5 x 10(4) CFU of N. asteroides into each mouse. Therapy was begun 24 h after inoculation and continued for the next 96 h. Dosages of antimicrobial agents resulted in concentrations approximating levels in human serum. Animals from each of nine treatment groups were sacrificed every 24 h. The pulmonary tissue obtained was homogenized and quantitatively cultured. Results were calculated to indicate the number of CFU per gram of lung tissue. Amikacin and imipenem were the two most effective single agents studied. Sulfadiazine and ciprofloxacin were ineffective, and ceftriaxone reduced bacterial counts modestly. Combination therapy did not enhance the bactericidal activities of the agents tested. We conclude that amikacin and imipenem, as well as select broad-spectrum cephalosporins, represent therapy superior to the sulfonamides in this experimental model and may represent alternative treatment for patients who cannot tolerate sulfa agents (e.g., human immunodeficiency virus-infected patients) or who fail primary treatment.

Antimicrobial synergism in the therapy of experimental cerebral nocardiosis.

A mouse model of cerebral nocardiosis was used to determine the efficacy of synergistic antimicrobial combinations in reducing bacterial colony counts per gram of brain tissue. The combinations of imipenem-cefotaxime and imipenem-trimethoprim/sulphamethoxazole (TMP/SMP) were compared with each other and with each agent used alone. A saline treated control group was also included. At the completion of 72 h of therapy the combinations of imipenem-cefotaxime and imipenem-TMP/SMX were the most effective in reducing bacterial colony counts. These were statistically superior to cefotaxime and TMP/SMX used alone but not statistically superior to imipenem alone. TMP/SMX was not effective in this model and was inferior to all other antibiotic treatments.

Cryptococcal arthritis in a patient with acquired immune deficiency syndrome. Case report and review of the literature.

A patient with acquired immune deficiency syndrome (AIDS) and cryptococcal arthritis occurring in the setting of disseminated cryptococcosis is described. The literature of cryptococcal arthritis is reviewed and the association of this unusual infection with AIDS is discussed. To our knowledge, this is the first reported association between AIDS and cryptococcal arthritis.

Synergistic effect of N-formimidoyl thienamycin with gentamicin and amikacin against Streptococcus faecalis.

The in vitro activities of N-formimidoyl thienamycin alone and in combination with amikacin and gentamicin were tested against 10 strains of Streptococcus faecalis. Synergy was demonstrated in 35% of the combinations tested by the microtiter checkerboard technique; 50% were found to be synergistic with time killing curves.