Assessment of methicillin resistant Staphylococcus Aureus detection methods: analytical comparative study

• Published in: The Pan African medical journal Vol. 27; no. 281; p. 281
• Main Authors: Ibrahim, Omer Mohammed Ali, Bilal, Naser Eldin, Osman, Omran Fadl, Magzoub, Magzoub Abbas
• Format: Journal Article
• Language: English
• Published: Uganda African Field Epidemiology Network 2017; The African Field Epidemiology Network; The Pan African Medical Journal
• Subjects: Anti-Bacterial Agents - pharmacology; Antibiotics; Bacterial Proteins - genetics; Cefoxitin - pharmacology; Deoxyribonucleic acid; DNA; DNA polymerase; Drug Resistance, Bacterial; Gene expression; Hospital costs; Humans; latex agglutination sensitivity; Latex Fixation Tests; Medical laboratories; Methicillin-Resistant Staphylococcus aureus - drug effects; Methicillin-Resistant Staphylococcus aureus - isolation & purification; Methods; Microbial Sensitivity Tests; Microbiology; mrsa; Oxacillin - pharmacology; oxacillin disc test; Penicillin; Penicillin-Binding Proteins - genetics; Polymerase Chain Reaction - methods; Sensitivity and Specificity; Staphylococcal Infections - diagnosis; Staphylococcal Infections - diet therapy; Staphylococcal Infections - microbiology; staphylococcus aureus; Staphylococcus infections; Temperature; Sudan; latex agglutination sensitivity; oxacillin disc test; Staphylococcus aureus; MRSA
• ISSN: 1937-8688; 1937-8688
• DOI: 10.11604/pamj.2017.27.281.9016

The heterogeneous expression of methicillin resistance in (MRSA) affects the efficiency of tests available to detect it. The objective of this study was to assess four phenotypic tests used to detect MRSA. This is an analytical comparative study conducted among sudanese patients during period from May 2012 to July 2014, strains were isolated and identified by conventional methods, and then confirmed by PCR detection of coagulase gene. PCR detection of mecA gene was used as a gold standard to assess oxacillin resistance screen agar base (ORSAB), oxacillin disc, cefoxitin disc (at different temperatures and incubation periods) and MRSA-latex agglutination test. ATCC 25923 was used as control. Sensitivity and specificity were calculated. MRSA- latex agglutination was the most accurate test; it showed 100% of both sensitivity and specificity, followed by cefoxitin disc with sensitivity of 98.48% and specificity of 100%. However, both of oxacillin disc and oxacillin resistance screen agar base showed less accurate results, and were affected by incubation periods. Oxacillin disc after 24 h incubation both at 30°C and 35°C showed sensitivity and specificity values of 87.88% and 96.23%, respectively. However, after 48h incubation the test at 30°C showed sensitivity and specificity values of 89.39%, and 94.34%, respectively. At 35°C (48h) it showed values of 89.39%, 92.45% respectively. Specificity of ORSAB was more than oxacillin disc at 35°C after 24h incubation 98.11% and 96.23%, respectively. MRSA- latex agglutination and cefoxitin disc diffusion tests are recommended for routine detection of MRSA.