Drug sensitivity using counter diffusion technique in methicilinresistant staphylococcus aureus in clinical isolates: A survey of hospitals patients admitted within Nakuru county

Abstract

Several infectious bacterial strains have acquired resistance towards most available antibiotics. Therefore, there is need to study drug sensitivity using counter diffusion technique for methicillin resistant Staphylococcus aureus (MRSA) 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 specific objectives were to compare the susceptibility pattern for the MRSA organism using the Kirby Bauer disc diffusion and compare it to the counter diffusion technique; To determine which antimicrobial agent combination are sensitive to MRSA; To compare the prevalence of methicillin sensitive Staphylococcus aureus (MSSA) and MRSA and ; To establish the prevalence of MRSA according to the sites. The study sought to fill the literature gap by investigating drug sensitivity using counter diffusion technique in MRSA. Laboratory procedure included Sample collection, Culture, Gram staining and biochemical testing Kirby Bauer disc diffusion done following Clinical and Laboratory Standards Institute (CLSI) guidelines. Counter diffusion technique as per the protocol for the study. Data were analyzed using R version 3.2.0. Proportions were compared using Chi square or Fisher’s exact test. Cohen’s Kappa was used to assess the inter-drug reliability in detecting the MRSA and MSSA sensitivity of the 11 drugs on the isolates. A simple linear regression analysis was used to study the relationship between the zones inhibited and the technique used. In the model zone was the outcome variable and technique was the covariate, with the latter two being compared to the counter diffusion technique. All tests were performed at 5% significance level. Of 423 patients recruited, 344 (181 males and 163 females) had cases of Staphylococcus species isolated 12.5% (95% CI 17.8-16.5%) of the 344 were Methicillin resistant whereas the rest were Methicillin sensitive, Proteus species 30 cases, Escherichia coli (E. coli) 45 cases, Klebsiella species 4 cases. The proportion resistant was 14% and 11% among males and females, respectively. These two proportions were not significantly different from each other (Chi square= 0.374, df = 1, p = 0.540). The results further indicated that the prevalence of MRSA varied significantly by site (Fisher’s exact test p<0.001), with wounds recording the highest at (17.9%) followed by central venous catheter (CVC) (16.7%), nasal (9.1%), and stool and urine at zero percent. It informs general public on the gains made in the drug sensitivity using the technique. Scholars will use the study as a background for their own academic papers. The study found that, MRSA is a real medical threat within Nakuru County. Proper wound management should be maintained since it was found that MRSA was higher in wound specimen more so those that were septic. The researcher recommends that, the procedure be validated and accepted as marker for testing for the drug combination therapy as it has potential to pinpoint to clinicians the way forward in patient management. Surveillance of MRSA as a means of identifying colonized or infected patients should be implemented since most of isolated cases were from patients who are admitted.