In-vitro anti-microbial susceptibility of clinical isolates of pathogenic bacteria to ten antibiotics including phosphomycin.

The minimum inhibitory concentration (MIC) of ten antibiotics was determined for various bacterial pathogens isolated from clinical specimens in a Lagos hospital. The in-vitro activity of penicillin and tetracycline was not very impressive and a similarity was noticed in the resistance patterns of these two antibiotics, while the activity in vitro of the relatively more toxic aminoglycosides and chloramphenicol was high for Gram-negative rods. Ceftazidime demonstrated the highest activity in vitro against all pathogens studied. Cefoxitin, cefuroxime and phosphomycin demonstrated an impressive activity in vitro. Clindamycin was very active against strains of Staphylococcus aureus. beta-lactamase production amongst these strains was studied and the clinical significance of this and their MIC results are discussed.