Validity of Cefoxitin Disc Diffusion Test for the Detection of Methicillin-resistant Staphylococcus Aureus

Abstract

Definite detection of MRSA is important for proper treatment. The purpose of the present study was to measure the validity of cefoxitin disc diffusion test for the detection of methicillin-resistant Staphylococcus aureus. This cross-sectional study was carried out in the Department of Microbiology and Immunology at Bangabandhu Sheikh Mujib Medical University, Dhaka from January 2010 to December 2010 for a period of one (01) year. S. aureus isolates were collected from different clinical samples including wound swab, pus, blood, urine, tracheal aspirate, throat swab, aural swab etc. Staphylococcus aureus (S.aureus) were isolated and confirmed by staining, biochemical tests. Routine antimicrobial susceptibility testing was performed cefoxitin discs diffusion test. PCR was performed for detection of the mecA gene for MRSA. Out of the 22 suspected MRSA isolates 19 were mecA positive by PCR and all of them 19(100.0%) were resistant to cefoxitin disc diffusion. The comparison of oxacillin and cefoxitin resistance and presence of mecA gene by PCR showed that out of 22 suspected MRSA isolates 19 were mecA positive by PCR and all the 19 (100.0%) showed resistance to cefoxitin disc diffusion. The sensitivity and specificity of cefoxitin disc diffusion were 100.0% and 100.0% respectively. Cefoxitin disc diffusion test has high sensitivity and specificity for the detection of MRSA.

Methicillin Resistant Staphylococcus aureus (MRSA) Isolation and mecA Gene Detection from Milk and Farmer Hand Swab in Tulungagung, Indonesia

“…However, the oxacillin diffusion disk has a specificity of 74.07%, and the cefoxitin diffusion disk has a specificity of 92.59% (Sahai et al, 2014). However, according to some past studies, the cefoxitin disk diffusion approach was more sensitive than the oxacillin disk diffusion method when looking at MRSA, due to the high rate of false positives in the oxacillin disk diffusion method (Sultana et al, 2019). According to Bhutia et al (2012), Oxacillin resistance can result from false positives being affected by β-lactamase hyperproduction; however, there is no genotypic resistance mechanism.…”

IDENTIFIKASI BAKTERI Methicillin-Resistant Staphylococcus aureus PADA TELEPON GENGGAM MAHASISWA PSSKPD 2019 FAKULTAS KEDOKTRERAN UNIVERSITAS UDAYANA

“…Metode difusi cakram cefoxitin memiliki spesifisitas dan sensitivitas sebesar 100% sehingga menjadi metode yang telah banyak digunakan dalam mendeteksi MRSA. 17 Berdasarkan kriteria dari CLSI, bakteri S. aureus dikatakan resisten terhadap antibiotik cefoxitin atau MRSA jika memiliki zona hambat pertumbuhan sebesar ≤ 21 mm. 13 Prevalensi MRSA yang ditemukan dari penelitian ini adalah sebanyak dua sampel atau 50%.…”