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Volume 5 Issue 3 (March, 2017)

Original Articles

ASSESSMENT OF DIFFERENT TESTS FOR IDENTIFICATION OF STAPHYLOCOCCUS AUREUS FROM CLINICAL SAMPLES- A COMPARATIVE STUDY
Sushil Kumar Sharma, Neeru Garg, Raj Kumar Wasan, Rohit Wadhwa, Vijeta Chadha, Prabhjot Kaur

Background: Staphylococcus aureus is a frequently isolated pathogen and may be cultured early in infancy in cystic fibrosis (CF) patients. Previous reports have shown that a significant number of clinical isolates of methicillin-resistant S. aureus (MRSA) gave negative results by one of newer tests (Staphaurex;). Hence; we planned the present study to assess current versions of Staphaurex and compared them with other diagnostic tests. These diagnostic tests include free-coagulase test, bound-coagulase test.  Materials & methods: The present study included assessment of 150 consecutive clinical samples of S. aureus strains. For the determination of the methicillin susceptibility, a disk diffusion method on Mueller-Hinton agar using a 5-mg methicillin disk was used. Testing of a total of 200 staphylococcal isolates was done. In the end, the clinical samples yielded 100 S. aureus isolates derived from 60 patients. Following tests were used for the identification of S.aureus: Free-coagulase (tube) test, Bound-coagulase (agar) test, Staphaurex and Staphaurex Plus and Pastorex Staphplus. Strains with variable outcomes when the results of the different tests were compared were retested by all procedures mentioned previously and were subsequently studied further with the aid of the additional tests mentioned below.  All the tests and procedures were performed as per manufacturer’s condition. All the results were compiled and assessed by SPSS software. Results: 100 percent sensitivity was observed only in the Staphaurex Plus group. Inability of tests to identify some MRSA strains correctly resulted in the difference with the free-coagulase test, a bound-coagulase test, and the former Staphaurex test. Conclusion: Out of all the above mentioned tests, Staphaurex Plus exhibits maximum sensitivity.
Key words: Methicillin resistant, Staphylococcus aureus, Staphaurex

 
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