CORRELATION OF MINIMUM INHIBITORY CONCENTRATION OF CIPROFLOXACIN TO THE THERAPEUTIC RESPONSE OF PATIENT WITH URINARY TRACT INFECTION CAUSED BY ESCHERICHIA COLI

The choice of an antibiotic depends solely on the identification of the species by determination of the sensitivity characteristics of the microorganism. Along with the determination of sensitivity pattern, understanding the susceptibility pattern of particular strain isolated from patient is equally important. Variation in patient and microorganism is known to be key factor for predicting the outcome for individual patient and establishing targets for clinical susceptibility. Dosage adjustment in relation to minimum inhibitory concentration (MIC) of drug, taking into account underlying pathogen might affect the therapeutic response and hence improve clinical outcome of patient. Therefore, E coli positive urine cultures of patients who were prescribed Ciprofloxacin were collected and their MIC was determined by agar well diffusion method. The response of patient was obtained by direct interview with them after 3 days of Ciprofloxacin therapy. There is a direct correlation between MIC and therapeutic outcome of antibiotic therapy. The clinical success rate increases when MIC is <1mg/l whereas, patient becomes non respondent as MIC approaches to >4mg/l which can be categorized as susceptible and resistant respectively. Therefore, for best clinical outcome MIC lies in the range <1-4 mg/l which could be used to discriminate success and failure of Ciprofloxacin treatment. Breakpoint of Ciprofloxacin was also derived from the study which is 4mg/l. This study concludes that obtaining only sensitivity pattern of antibiotic is not sufficient for optimal antibiotic therapy because MIC of sensitive strains varies and so does the response in relation to the minimum inhibitory concentration.