In vitro susceptibility of coliform and Pseudomonasspecie to some antibiotics by E-test strips

The aim of this study was to characterize the in vitro antimicrobial susceptibility profile of Coliform and Pseudomonas species strains to 10 antibiotics (Vancomycine, Ciprofloxine, Tetracyclin, Chloramphenicol , Erythromycin, Streptomycine, Gentamycine , Ampicilline, trimethoprimsulfamethoxazole and Clarithromycin) that could potentially be used in clinical therapy. MIC was determined for antibiotics in Mueller-Hinton (MH) agar plates, by using E-test strips (Liofilchem, Roseto degli Abruzzi, Italy). MIC was read after 24 h of incubation at 37°C. The both strains were more susceptible to Ciprofloxine (MIC values: Coliform, 0.002 μg/mL; and Pseudomonas, 0.047 μg/mL). No strain of Pseudomonas was found sensitive to Chloramphenicol, Erythromycin, Ampicilline, trimethoprim-sulfamethoxazole and Clarithromycin, contrary to coliform, which was found resistant to those antibiotics with MIC values ranged between 0.38 and 128 μg/mL . Gentamycine (MIC values: Coliform, 0.125μg/mL; and Pseudomonas, 0.50 μg/mL), Tetracyclin (MIC values: Coliform, 1.00 μg/mL; and Pseudomonas, 0.75 μg/mL) and Streptomycine (MIC values: Coliform, 0.75 μg/mL; and Pseudomonas, 2.5 μg/mL) were also active against Coliform and Pseudomonas strains, while resistance to Vancomycine (no inhibition) was observed in the two strains