Comparative Study of various Growth Media in Isolation of Urinary Tract Pathogens

Abstract

Background: Since a wide spectrum of bacteria are responsible for causing urinary tract infections. To cover the maximum yield of isolates a study was designed in which a combination of media was used for detection of both gram positive and gram-negative bacteria.

Materials and Methods: A Combination MacConkey agar, Blood agar and Cystine lactose electrolyte deficient medium were used at one and same time to get the positive growth. The identification of responsible pathogens is confirmed by observation of colony characteristics, Gram staining and biochemical screening using different tests.

Results: Results Out of the one hundred isolates, two isolates showed growth only on MacConkey agar, 19 isolates were detected only on Blood agar and 15 pathogens grew only on CLED medium . Almost 50% of isolates grew on all the three media while 17% isolates showed growth on both blood agar and CLED medium. The combination of CLED medium and MacConkey agar showed the minimum yield.

Conclusion: The use blood agar, MacConkey agar and CLED medium at one and same time have minimum chances of missing cultures. It is proposed that for the isolation of gram-positive urinary tract pathogens blood agar when used singly covers the maximum range.