Prevalence and pattern of antimicrobial susceptibility of methicillin-resistant and methicillin-sensitive staphylococcus aureus in north Jordan

ABSTRACT

The main goal of this study is to determine the prevalence and pattern of antimicrobial susceptibility of methicillin-resistant [MRSA] and methicillin sensitive Staphylococcus aureus [MSSA] in north Jordan. The study also aims to evaluate the [MRSA] latex screen test for the detection of [MRSA]. One hundred and fifty isolates of Staphylococcus aureus, that were received at the clinical microbiology laboratory of the faculty of medicine at Jordan University of Science and Technology from two major hospitals in the north part of Jordan from September of 2007 to February of 2008, were included in the study. Ninety isolates were obtained from clinical specimens and sixty isolates from carrier patients. Staphylococcus areus strains were identified morphologically and biochemically by standard laboratory tests and procedures. Antimicrobial susceptibility was performed by the disk diffusion [Kirby-Bauer], and Minimum Inhibitory Concentration [MIC] method was used to identify methicillin resistance. The pattern of resistance to seven antimicrobials [Vancomycin, Cephalothin, Clindamycin, Cortimaxizole, Erythromycin, Gentamycine, and Penicillin G] showed that none of the intrinsic-resistant isolates were resistant to vancomycin. The majority of the isolates was recovered from anterior nares [60%] and the least from peritoneal and synovial fluid [0.7% each]. The majority of isolates were recovered from surgical specimens [40%] and the minority from the ophthalmology department [1.3%]. The pattern of antimicrobial succeptability was as follows MSSA [n=123], MRSA [n-27], Vancomycin [100%, 100%], Caphalothin [99.2%, 85.2%], Clindamycin [95.9%, 88.9%], Cotrimaxizole [98.4%, 85.2%], Erythromycin [81.3%, 40.7%], Gentamycin [95.9%, 85.2%], and penicillin G [4.9%, 0%]. The diffusion test showed a sensitivity of 100 and 88.9 and a specificity of 100 and 86.2, respectively. The pattern of antimicrobial susceptibility of S. areus differs between methicillin-sensitive and resistant isolates. Except for penicillin, most of methicillin-sensitive isolates were susceptible to nearly all antimicrobial agents used in this study