Suppurative Infections in Hospitalized Patients – An Ongoing MRSA Threat
Background: Penicillin resistance among Staphylococcus aureus commonly encountered in the hospital
admitted patients. Detection of antibiotic sensitivity in hospital acquired methicillin resistant Staphylococcus
aureus infections is important as it has great influence on empiric antibiotic prescription, successful control of
infection, prevention of spread of disease and successful patient management. This study aimed to detect
the frequency of HA-MRSA from pus samples in a hospital setup with assessment of their antibiotic susceptibility patterns.
Method: A cross-sectional study was conducted in the Microbiology department of Basic Medical Science
Institute, JPMC, Karachi from January 2015 until December 2015. Pus samples from surgical site wounds, skin
lesions, abscesses from surgical and medical wards and ICUs were collected. According to the standards
given by CLSI 2014, MRSA testing of the samples was done and susceptibility testing for antibiotics was
performed. Inducible clindamycin resistance was detected by D-Test. E Test determined the MIC (minimum
inhibitory concentration) for vancomycin. The data was analyzed by SPSS version 16.
Result: Out of the 149 MRSA identified from the pus samples, 106 (71.14%) samples were HA-MRSA. The
number of male patients was more than the female patients (67.66%). Out of the 106 HA-MRSA, 91(85.8%)
were sensitive to TMP/SMX, 98(92.5%) to rifampicin, 12(11.6%) to gentamicin, 85(80.2%) to tetracycline,
11(10.4%) to erythromycin, 37(34.9%) to clindamycin, 20(18.9%) to ciprofloxacin, 106 (100%) to both vancomycin and linezolid.
Conclusion: HA-MRSA showed sensitivity to TMP/SMX and vancomycin making them effective drugs to use
in combination in superficial infections. The drug linezolid also showed 100% sensitivity.