Invitro assessment of antibacterial activity of a combination of cloxacillin and an extract of tithonia diversifolia flowers against MRSA.

Abstract

ABSTRACT. Introduction. Staphylococcus aureus is a very common pathogen implicated in causing hospital acquired infections including skin, soft tissues, respiratory, bone, joint and cardiovascular diseases. The pathogen has exhibited resistance to a number of antibiotics; one of such resistant isolates is Methicillin resistant S. aureus. It is resistant to all currently available beta-lactam antibiotics. This leaves the only choice of treatment as second line agents for example Vancomycin and linezolid; these are expensive and very vulnerable to resistance. However, resistant species to vancomycin have also been isolated. Furthermore, the epidemiology of infections caused by MRSA are changing from being confined within the hospitals to being common within the community settings, and if the increasing antibiotic resistance is left un attended to, management of S. aureus infections may become too complex and no more effective antibiotics will be present for management of this infections in the near future. Therefore purpose of this study was to test for the activity of an essential oil extract from the flowers of T. diversifolia against MRSA and to further assess the antibacterial effect of combining its essential oil extract with cloxacillin against MRSA. Objectives. I. To assess the antibacterial activity of the essential oil extract from the flowers of T. diversifoliaagainst MRSA. II. To assess the antibacterial activity of the combination of essential oil extract from the flowers of T. diversifolia and cloxacillin against MRSA. Methodology The flowers were collected and the essential oil extracted by hydro distillation, its antimicrobial susceptibility against MRSA was tested, its MIC was also determined by MIC by agar well diffusion method. The MIC of cloxacillin was also determined. This was followed by determination of the FICI of the combination at different concentration ranges of the MICs of cloxacillin and the essential oil extract. Results. MIC of T. diversifolia flower’s essential oil and that of cloxacillin was determined to be 17mg/ml and 48µg/ml respectively. The FICI was 0.122.