Comparative Analysis of Methicillin-Resistant and Susceptible Staphylococcus aureus Using Cefoxitin as a Surrogate Marker

ABSTRACT
Objective: Staphylococcal infections are a major risk of morbidity among the community and hospital environment. The
study aimed to elucidate the occurrence of methicillin-resistant and susceptible Staphylococcus aureus (MRSA and MSSA) using
cefoxitin as a surrogate marker and to monitor resistance profile of MRSA and MSSA comparatively to ascertain the empirical
therapeutic preferences.
Methods: The clinical specimens collected prospectively from the various wards processed to isolate the staphylococcal
pathogens and antibacterial drug resistance using modern microbiological methods including Bactec FX (BD) and MicroScan
Walkaway plus System analyzer.
Results: We isolated a total number of 103 (51%) MRSA and 100 (49%) MSSA strains with a significantly higher incidence
of MRSA in surgical and intensive care unit (p = 0.01). MRSA resistance was significantly associated with co-amoxiclav, ampicillin, and penicillin (p < 0.001). MRSA strains manifested 3 (2.9%) cases resistant to each of the chloramphenicol, daptomycin,
vancomycin, and teicoplanin. The association of MSSA was significantly associated with chloramphenicol (p < 0.001), clarithromycin (p = 0.001), fusidic acid (p = 0.01), imipenem (p < 0.01), linezolid (p < 0.05) and rifampin (p < 0.01).
Conclusion: Emerging community and hospital-based cases of MRSA are troublesome that left us with therapeutic options to
chloramphenicol, daptomycin, vancomycin, teicoplanin, rifampin, and linezolid.