Effects of different groups of antibiotics on logarithmic growth of escherichia coli strains isolated from clinical sources

SUMMARY Effects of different groups of antibiotics on logarithmic growth of Escherichia coli strains isolated from clinical i- sources, Effects of different groups of antibiotics on logarithmic growth of Escherichia coli strains isolated from clinical sources have been searched. As different groups of antibiotics, Ampicillin from Penisillins, Oefo- pera2?one from third generation Cephalosporins, Oxytetracyc-, :> line from Tetracyclines, Gentamycin from Aminoglycosides have been selected. Optimum growth conditions has been detected." and standardized in aerationed DST Broth*, Optical density of cultures and numbers of colony forming unit in per mililiter depend on time have been found in 4-95 üsu determined as optimum wave-length. Standard growth curves have been obtained by plotting their» in semi-logarithmic paper * îhe effect of each antibiotic with different concent rations in related to production period and growth conditions has' heeri tested by measuring optical density» The effect of antibiotics on logarithmic growth of EUcoli strains has changed oj depending on their effective concentrations in media and experimental time. It has been observed that repeatable results with minimum faults can be obtained when experiments with standardised conditions have been made within sufficient time intervals* ¥e have concluded that while optimum antibiotic concentration is being found in experiments made under fluid media, tests should be made within sufficient time intervals under standard conditions?