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Biosensor for Detection of Antibiotic Resistant Staphylococcus Bacteria
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Biosensor for Detection of Antibiotic Resistant Staphylococcus Bacteria

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Phenotypic and genotypic methods for the detection of methicillin resistant coagulase negative staphylococci: a

Shubhra Singh1, Gopa Banerjee, S K Agarwal

  • 1P.G. Department of Microbiology, CSMMU, Lucknow.

The Journal of Communicable Diseases
|October 21, 2011
PubMed

Insights

Methicillin-resistant Coagulase-negative Staphylococci (CoNS) cause significant nosocomial infections. This study compared phenotypic methods, like cefoxitin disk diffusion, with genotypic PCR for detecting methicillin resistance in CoNS.

Area of Science:

  • Clinical Microbiology
  • Infectious Diseases
  • Antimicrobial Resistance

Background:

  • Coagulase-negative Staphylococci (CoNS) are a leading cause of hospital-acquired infections.
  • Methicillin resistance in CoNS presents a significant clinical challenge.
  • Accurate detection of methicillin resistance is crucial for effective treatment.

Purpose of the Study:

  • To compare the efficacy of various phenotypic methods against genotypic Polymerase Chain Reaction (PCR) for detecting methicillin resistance in CoNS.
  • To evaluate the diagnostic performance of oxacillin and cefoxitin in different phenotypic assays.

Main Methods:

  • 100 CoNS isolates were analyzed.
  • Polymerase Chain Reaction (PCR) served as the gold standard for mecA gene detection.
  • Phenotypic methods included disk diffusion (DD), agar dilution (AD), and a modified method (MHOX) using oxacillin and cefoxitin.

Main Results:

  • Cefoxitin disk diffusion showed 88.46% sensitivity and 100% specificity.
  • Oxacillin agar dilution demonstrated 86.53% sensitivity and 79.16% specificity.
  • The MHOX method exhibited 96.16% sensitivity and 72.91% specificity.

Conclusions:

  • Cefoxitin disk diffusion and oxacillin agar dilution are suitable initial tests for identifying methicillin resistance in CoNS.
  • The MHOX method shows potential as a reliable single test for detecting mecA gene-mediated oxacillin resistance in all CoNS species.

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