The Efficacy of Antiseptic Agents Utilized at Kenyatta National Hospital Burns Unit Against Bacteria Isolated From Infected Wounds

Abstract

Background: Burn injury in the Kenyan population is associated with extended hospitalization, deformity and disabilities, which induces stigma and rejection. In addition, the highly resistant and opportunistic bacteria that infect the wounds complicates patient management. Burn-injury patients with bacterial infections, especially those associated with multidrug-resistant (MDR) strains are likely to be at higher risk for untreatable or difficult to treat infections. Therefore, use of antiseptics at an effective concentration, diluted in a clean environment and cessation of their applications when the clinical features of infection immediately fade results in reduction of burn wound infections. Broad Objective: To identify the type, concentration, sterility and efficacy of antiseptic solutions against bacteria isolated from burn wounds in patients admitted at Kenyatta National Hospital (KNH) burns unit. Methodology: This was a cross-sectional study carried out at KNH Burns unit. A total of 81 wound swab samples were consecutively collected from patients presenting with acute burn wounds after carefully cleaning with normal saline over a period of three months. Growth on Blood agar and MacConkey agar was evaluated for colonial morphology; gram stain and biochemical tests were used for species identification. The isolated bacteria were subjected to antiseptics to determine the efficacy. Discrete colonies were then stored at -20℃ in Skimmed Milk media in the department of Medical Microbiology UoN. Descriptive analysis was done to determine the frequencies and proportions of the variables and presented in tables and graphs where appropriate. Chi Square test was used to determine correlation between concentration of antiseptics and susceptibility of isolated bacteria. A p-value of < 0.05 was considered statistically significance. Results: A total of 81 swabs collected from burn wound patients had bacterial growth. Staphylococci aureus (48.1%, 39/81), Proteus species (30.9%, 25/81), Pseudomonas aeruginosa (16.0%, 13/81), and Klebsiella species (1.2%, 1/81) were the most predominant species isolated. The unidentified organisms were (3.7%, 3/81). Among the positive samples more than eighteen percent had mixed bacterial growth. The effective antiseptics tested against isolated bacteria were acetic acid 4% and chlorhexidine digluconate 5% w/v when their concentrations are xiv increased gradually, while 1% of silver nitrate 0.01% recorded low bacteriostatic activity. This study revealed that in comparison to 5% chlorhexidine digluconate w/v and silver nitrate 0.01% w/v, acetic acid solution is a much more effective antiseptic against bacteria isolates infecting burn wounds as it showed 100% bactericidal activity against all the infecting bacterial agents at a concentration 4%. The study also confirmed that a combination of the different concentrations of the three and/or two consecutively tested antiseptics had higher microbiocidal efficacy than when each was tested individually. Conclusion: Staphylococcus aureus and Proteus species were the most frequently isolated bacteria infecting the burn wounds. The bactericidal and bacteriostatic activity of the antiseptics solutions utilized at KNH burns unit was different depending on the concentration and organism isolated. Four percent of acetic acid and 5% chlorhexidine digluconate w/v solutions were found to be more effective both showing bactericidal and bacteriostatic activities while 1% silver nitrate 0.01% w/v was found to be bacteriostatic. In addition, we also noted bactericidal activity when the antiseptic agents were combined against all the bacteria isolated.