Synergism between nigella sativa seeds extract and synthetic antibiotics against Mec A gene positive human strains of staphylococcus aureus

Abstract

Background and Objective: Synergistic combinations of various antimicrobial agents have been introduced as extra successful strategies to combat multidrug resistant (MDR) infections. This study was undertaken to evaluate MDR profiling of Staphylococcus aureus strains isolated from clinical specimens of two public hospitals of twin Pakistani cities as well as to explore in vitro antibacterial potential of Nigella sativa L. (black cumin or black seeds) extract against Mec A gene positive Staphylococcus aureus strains. Materials and Methods: The MDR strains were then screened for positive Mec A gene by PCR and sequencing. A total of 500 bacterial strains were subjected to antimicrobial and Nigella sativa seeds susceptibility and minimal inhibitory concentration assays. The data were evaluated as Mean±Standard deviation of five independent experiments. The results were analyzed using t-test with SPSS version 16.0. Results: Methanolic extracts of Nigella sativa seeds showed maximum activity against Mec A gene positive Staphylococcus aureus alone and in combination with the penicillin antibiotic Augmentin® plus the second-generation Cephamycin, Cephalosporins, Mefoxin® (Cefoxitin). The anti-MRSA activity was reduced when methanolic extracts of Nigella sativa seeds were used in combination with the pain reliever and the fever reducer paracetamol (acetaminophen). Eventually, it has been observed that the anti-staphylococcal activity of Nigella sativa led to changes in bacterial cell morphology indicating that the cell wall of Gram-positive bacteria as likely a target of action. Conclusion: This study provides new insights about synergistic antimicrobial and Nigella sativa crude extract activities against MDR Staphylococcus aureus strains.