Comparative phenotypic and genotypic study of MSSA and MRSA wound infections in Babylon

Abstract EN

The study aim to evaluate and compare phenotypic and genotypic features of methicillin sensitive (MSSA), and methicillin resistance (MRSA) S.

aureus isolates.

Out of 113 infected wound swabs from outpatient clinic in Babylon/Iraq, only (31) (27.43%) S.

aureus isolates were isolated by selective medium, and cefoxitine disk diffusion was used to differentiate MSSA from MRSA in order to study the comparative phenotypic and genotypic features.

Vancomycin minimum inhibitory concentration (MIC) was used also.

The PCR assay was used for direct detection of methicillin (mec A) and vancomycin (van A) antibiotics resistance gene in S.

aureus isolates.

Results showed that (17) out of (31) isolates were MRSA, fifteen of them harbor Mec A gene.

While only (14) out of (31) isolates were MSSA, two of them harbor the Mec A gene, and there was no single vancomycin resistance in all isolates.

Two (2) MRSA isolates have intermediate vancomycin susceptibility (MIC 8-16μg/ml) and just two (2) isolates having Van A gene.

MRSA nearly resist all β lactam, cloxacillin, gentamycin and ciprofloxacin, while the MSSA isolates were sensitive for the commonly used antibiotic with high resistant rate to penicillin, amoxicillin and amoxicillin clavulante.

In conclusion, MRSA has become a major public health problem with decreased susceptibility to antibiotics that necessate the availability of highly sensitive diagnostic test like PCR with routine laboratory techniques (based on the detection of the mec A gene) (or cefoxitine disc diffusion method) to differentiate MSSA from MRSA and the availability of the highly active antibiotic in order to control their spreads as early as possible