A COMPARATIVE STUDY TO DETERMINE THE ACCURACY OF DIRECT SUSCEPTIBILITY TESTING WITH CONVENTIONAL ANTIMICROBIAL SUSCEPTIBILITY TESTING

Abstract

Introduction: Clinically significant bacteria are identified in the laboratory and the accurate information isprovided with antimicrobial susceptibility testing (AST) which is essential for an accuratemanagementofpatientssufferingwith abacterial infection orbacterialdisease[1].As the process of AST istime consuming and Results of AST are provided with in a timespan of 48–72 h after sampling.Disk diffusion has many benefits, which includes low expenditure, time duration reduction ofresults and few more basic benefits. One of the benefits is the probability or chances ofexecuting direct susceptibility testing (DST).when is potentially very useful in the management of critically used selectively and interpreted carefully, DST on clinical samples ill patients, as the time to results is shortened by approximately 24 h. Aim:To do a comparative study for determining the accuracy of direct susceptibility testing with conventional antimicrobial susceptibility testing. Material And Method:This cross- sectional study was conducted in the Department of Microbiology, peoples College of MedicalSciences and Research Centre, over a period of 1 year-from February 2021 to February 2022. Result:A total of 311 samples of urine, pus and body fluid were collected and positive sample processed from 124males and 187 females from age groups 1 to 90 years.From total of 311 samples Out of all the samples 132 were of pus, 175 were of urine specimen 4 were offluidssamples.Comparison of the bacterial response to 14 antimicrobial agents using directantimicrobial sensitivity testing (DST) versus standard antimicrobial sensitivity testing(AST) for Gram positive bacteriaOut of 91 gram positive bacteria we found that on performing AST and DST on norfloxacin probability valuewas 1, which shows that there is no significant difference in results by these two methods. Similarly,Ciprofloxacin, Cefoxitin, Doxycycline, Amoxy-clavulanic acid, Erythromycin, Clindamycin, Linezolid,Chloramphenicol, Cefuroxime all have a p-value as 1 on performing both the different types of antimicrobialsusceptibility testing method which indicates a similarity in their results. Conclusion:After 1 year of systematic study even though we found that AST and DST both gives almost similar result, but keeping in mind major and minor differences in antibiotic sensitivity test . We should consider it only foremergencypurposes.In emergency it is observed that DST proved to be more successful because DST provides results with in 24to 32 hours, this providing results faster but it should always be followed by AST for confirmation of results.With DST, we have to apply more no. of antibiotics disk to coues all bacteria increasingcost of ABST.