Efficiency of chromogenic medium (HiChrome universal medium) for Identification of Organisms causing Burn Wound Infection and Their Pattern of Antimicrobial Susceptibility at Ain Shams University Hospitals

Abstract

Background: Burn wound infections are one of the most dangerous burn complications because they are a leading cause of morbidity and mortality in burn patients. Their successful treatment necessitates the rapid isolation and identification of causative species using antibiotic susceptibility patterns that are acceptable. Aims and objectives: To evaluate the efficiency of the chromogenic medium (HiChrome universal medium) in comparison to conventional method in identification of organisms causing burn wound infections regarding time, accuracy and cost and profiling of antimicrobial susceptibility patterns of burn wound isolates. Methods: Eighty-three wound samples were collected from inpatient and ICU patients at Ain Sham University Burn Unit. All the wound swabs were analysed using conventional media and chromogenic medium (HiCrome Universal medium) to compare between their results. Antibiotic sensitivity testing was done using disk diffusion method. Results: HiChrome universal medium was effective and could identify all organisms in the obtained samples within 24 hours and its efficiency was almost the same as conventional method including (nutrient, blood and MacConkey' s agar medium followed by biochemical tests) but more rapid. Out of the 83 swabs taken, positive growth was detected in 81 swabs (97.5%). Out of this, Gram negative organisms were isolated from 45(54.2%) isolates while 21(25.3%) grew solely Gram positive organisms. However 15(18.1%) grew mixed Gram positive and negative organisms. Staphylococcus aureus (30.1%) was the commonest among Gram positive organisms 25(30.1%) and Pseudomonas aeruginosa 38(45.8%) was the commonest among Gram negative organisms. Vancomycin was the most effective antibiotic against Gram positive bacteria and Imipenem was the most effective against Gram negative organisms. Conclusion: HiCrome Universal agar can be used to quickly isolate all organisms with low cost.