Comparison of Oxacillin and Cefoxitin for the Detection of mecAGene to Determine Methicillin Resistance in Coagulase Negative Staphylococci(CoNs)

J Coll Physicians Surg Pak. 2017 Aug;27(8):520-522.

Abstract

The aim of the study was to compare the effectiveness of Cefoxitin with that of Methicillin/Oxacillin in the determination of mecAgene in Methicillin resistant Coagulase-negative staphylococci(CoNS). We assessed 57 CoNS isolates for mecA gene via PCR, which were subsequently subjected to Methicillin/Oxacillin and Cefoxitin disc diffusion test. These methods are simple, inexpensive and easily available compared to PCR despite less specificity. Out of 41 mecApositive species, 33 (80.5%) were resistant to Methicillin/Oxacillin. Cefoxitin-resistance was seen in all 41 (100%) mecApositive samples. Two (12.5%) mecAnegative isolates of S.saprophyticuswere Methicillin/Oxacillin resistant, but were Cefoxitin sensitive. Four (9.7%) isolates of S.saprophyticus, three (7.3%) of S.epidermidisspecies, and one (2.4%) S.haemolyticusthat were mecApositive were sensitive to Methicillin/Oxacillin but resistant to Cefoxitin. Cefoxitin resistance provides a more accurate picture of mecAgene positivity as compared to Methicillin and Oxacillin.

Publication types

  • Comparative Study

MeSH terms

  • Anti-Bacterial Agents / pharmacology*
  • Bacterial Proteins / drug effects
  • Bacterial Proteins / genetics
  • Bacterial Proteins / isolation & purification
  • Cefoxitin / pharmacology*
  • Coagulase / metabolism
  • Drug Resistance, Bacterial
  • Genes, Bacterial / genetics
  • Humans
  • Methicillin / pharmacology*
  • Methicillin Resistance / genetics*
  • Microbial Sensitivity Tests
  • Oxacillin / pharmacology*
  • Penicillin-Binding Proteins / drug effects
  • Penicillin-Binding Proteins / genetics
  • Penicillin-Binding Proteins / isolation & purification
  • Polymerase Chain Reaction
  • Predictive Value of Tests
  • Sensitivity and Specificity
  • Staphylococcal Infections / drug therapy
  • Staphylococcal Infections / microbiology*
  • Staphylococcus / drug effects*
  • Staphylococcus / isolation & purification*

Substances

  • Anti-Bacterial Agents
  • Bacterial Proteins
  • Coagulase
  • MecA protein, Staphylococcus epidermidis
  • Penicillin-Binding Proteins
  • mecA protein, Staphylococcus aureus
  • Cefoxitin
  • Methicillin
  • Oxacillin