Evaluation the Uricase Produced from Different Clinical isolates of Pseudomonas aeruginosa by Plate Assay Methods

Abstract

Out of 150 clinical samples, 43 isolates of P. aeruginosa were identified based on biochemical tests, API 20 NE, and VITEK 2 system. The results showed that 38 (88.37%) isolates were uricase producers while only 5 (11.62%) isolates were uricase non producers, based on uricolytic activity on agar medium using two methods, qualitative method by using agar plate medium which contains many ingredients (uric acid, dextrose, yeast extract and NaCl), the results obtained by this method indicated by the presence of clear zone around streaking line on an agar plate assay. The another method is semi quantitative, in which agar plate medium contains 0.5%w/v uric acid as the only nutrition source and showed diameter of clear zone around well on an agar plate. The diameter of clear zone around wells ranged between 12-26 mm. In conclusion, both methods gave same results for screening uricase producers, but semi quantitative method gave more accurate results because its medium contain only uric acid as a source of carbon or nitrogen or both which makes this method more specific and sensitive than the other one.