Detection of slime production by coagulase-negative Staphylococcus: an assessment of two methods

The detection of slime can be helpful in determining the diagnostic value of coagulase-negative Staphylococcus (CNS). Here, we have made a comparative study of two phenotypic methods of slime production test from 28 clinically significant blood culture isolates of CNS. A total 16 out of 28 isolates (57.1%) were positive for slime by either of the tests, whereas only 5 out of 28 isolates (17.9%) were positive for slime by both the tests. The tube method detected slime in significantly more number of isolates than the spectrophotometric method (14 vs. 7; p<0.0483279). A weak correlation was found between the tube method and the spectrophotometric method (rs=0.2474). The tube test was found to be superior to the spectrophotometric test in terms of sensitivity, ease of performance and interpretation, and cost effectiveness.