In vitro interaction of kanamycin with cefotaxime

A study was conducted to investigate the in vitro interaction between kanamycin and cefotaxime. Three aqueous concentrations of kanamycin [5, 15 and 20 ug/m1] and four concentrations of cefotaxime [100, 200, 400 and 600 ug/m1] were incubated alone and in mixtures for a period of 3 days at 37C. Samples were taken every 12 hours and analyzed for each antibiotic activity. Degradation of kanamycin in presence of different concentrations of cefotaxime was significantly greater than kanamycin alone. However, no significant difference could be traced between cefotaxime concentration and the extend of kanamycin degradation was not significantly altered in presence of kanamycin. The abovementioned findings were related to the fact that the used concentration of cefotaxime for exceeded those of kanamycin

Antibacterial activity of cefoperazone alone and in combination with aminoglycoside antibiotics

The in-vitro antibacterial activities of cefoperazone [Cef], amikacin [Am], tobramycin [Nn] and gentamicin [Gm] as well as the combinations of cefoperazone with the three aminoglycoside antibiotics were tested againts five strains of each of Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus using the checkerboard agar dilution method. All antimicrobial combinations demonstrated some synergy and no antagonism was observed. A synergistic effect was observed with the combinations of cefoperazone plus amikacin, cefoperazone plus tobramycin and cefoperazone plus gentamicin against four of five and three of five of the tested clinical isolates of Pseudomonas aeruginosa and Escherichia coli respectively. Staphylococcus aureus clinical isolates exhibit an additive or indifferent effect towards all tested combinations. No antagonistic activities were found with any of the strains using such combinations

Production of aminoglycoside inactivating enzymes by pseudomonas aeruginosa

Thirty strains of Pseudomonas aeruginosa were isolated from urinary tract infections, burns and osteomyelitis [10 strains from each clinical source]. The aminoglycoside resistance patterns [markers] were determined by the disc agar diffusion technique using the aminoglycoside antibiotic discs [micro g/disc]; amikacin [Am,30], gentamicin [Gm. 10], kanamycin [Km. 30], tobramycin [Nn, 10], streptomycin [Sm. 10], and neomycin [Nm. 30]. The crude enzymes obtained by sonication of the cells of the isolated strains of Pseudomonas aeruginosa largely inactivated the used aminoglycosides in the presence of adenosine triphosphate [ATP] or acetyl Co-A as cofactors. The three inactivation mechanisms were detected, kanamycin phosphotransferase and streptomycin adenyltransferase were predominant among 90% or more of the strains, however, gentamicin adenyltransferase was limited. There were only two acetylating enzymes; kanamycin acetyltransferase [produced by 60% of the tested strains] and gentamicin acetyltransferase which was produced by only 11 strains [36.7%]. The aminoglycoside resistance pattern was correlated to some extent, with the production of the aminoglycoside inactivating enzymes