Drug Sensitivity Testing Using Counter Diffusion Technique on Methicilin-Resistant Staphylococcus aureus in Clinical Isolates within selected Hospitals in Nakuru County

Abstract

Several infectious bacterial strains have acquired resistance towards most available antibiotics and it’s for this reason that, there is need to study drug sensitivity using counter diffusion technique for methicillin-resistant Staphylococcus aureus in isolates so that combination therapy can be embraced since the core factor in using the method is the ability to give good synergistic potential among the drugs. The specific objective was to find out the susceptibility pattern for the MRSA organism using the disc diffusion and compare it to the counter diffusion technique. This was a cross sectional study design and simple random sampling was used to select patients to be surveyed from each of the randomly selected six hospitals. A total of 423 samples were used. A standard laboratory technique was used in the study and MRSA screen test and sensitivity testing were also used. The MRSA was 100 % resistant to licomycin, gentamycine and negative control and 100% sensitive to vancomycin and counter diffusion technique. Duncan Multiple Range Test established that lincomycin, gentamycin and the negative control did not show any significant differences between them, but they varied significantly with the positive control and the counter diffusion treatments. Positive control and counter diffusion also varied significantly. No child was resistant. A comparison of the susceptibility pattern for the MRSA organism using disc diffusion and counter diffusion technique indicated that the mean zone of inhibition using the counter diffusion technique was 27.1mm and was significantly higher than the zones of inhibition by either lincomycin p-0.0001, or gentamycin p<0.0001