Methicillin-resistance Staphylococcus aureus in southeast Iran: Herbal control and detection methods comparison

Abstract

Methicillin-Resistant Staphylococcus aureus (MRSA) is a type of staph bacteria that has developed resistant to certain antibiotics such as beta-lactams. Rapid and sensitive detection of MRSA strains in patients, of course, improves the global health status. In the present study we compared the sensitivity and specificity of a rapid Polymerase Chain Reaction (PCR) assay with a traditional empiric therapy in MRSA detection, using a literature-derived model. Furthermore, we tested Aloe Vera (AV) and Trachyspermum ammi L. (TAL) extracts for evaluating their antibacterial potency against MRSA. Twenty five S. aureus isolated from the nose and throat of totally 160 samples in 3 different groups, including 80 healthy subjects, 40 hospital staffs and 40 inpatients. The results of disk diffusion method showed that phenotypic antibiotic resistance percent in S. aureus isolates were entirely classified as cloxacillin (100%), methicillin (100%), penicillin (88%), cefixime (72%), azithromycin (56%), kanamycin (48%), clarithromycin (48%), ampicillin (48%), erythromycin (48%), amoxicillin (32%) and tetracyclin (8%). The distribution of antibiotic-resistant mecA gene according to PCR was 40%. Moreover, the best Minimum Inhibitory Concentration (MIC) and Minimum Bacterial Concentration (MBC) were 0.3 and 0.62 for both AV and TAL. Totally, 76% of MICs observed as cloxacillin-resistant. We concluded that the mecA gene-PCR assay is a rapid, sensitive and clinically useful test for early detection of MRSA. It is also recommended that more chemical investigations on AV and TAL require for introducing these extracts as antibacterial agents for control of MRSA.