Colonization of burn wounds in Ain Shams University Burn Unit

A prospective study was carried out on 70 burned patients admitted to the Burn Unit, Ain Shams University Hospital, Cairo, with the aim to verify the pattern of microbial colonization of burn wounds. Throughout the study period starting from 1 June 1999 till 31 May 2001, 281 sampling procedures (surface swabs) were performed from the burn wounds. A total of 301 microbial isolates were grown in cultures. Eight different species of bacteria, and only one species of Candida (C. albicans) were detected. There was no incidence of recovery of anaerobic microorganisms. Our results revealed that the most frequent isolate was Pseudomonas aeruginosa (21.6%), followed by Klebsiella pneumoniae (15.2%), then Escherichia coli (13.6%), Staphylococcus aureus (13.2%), coagulase-negative Staphylococci (11.6%), Streptococcus pyogenes (8.3%), Enterobacter species (6.6%), and lastly Streptococcus faecalis and Candida albicans (5.9 and 3.6%, respectively). Studying the time-related changes in burn wound microbial colonization showed an initial predominance of gram-positive cocci upon admission (70.7%) over gram-negative bacilli (27.6%). During the first 5 days, gram-negative bacilli started to predominate (55.7%) over gram-positive cocci (40.3%). Burn wound sampling performed starting from the sixth day onwards, revealed further prevalence of gram-negative bacilli (72.7%) over gram-positive cocci (22.7%). As for Candida albicans, there was a gradual increase in the frequency of its recovery as time elapsed from admission. It is crucial for every burn institution to determine the specific pattern of burn wound microbial colonization, the time-related changes in the dominant flora, and the antimicrobial sensitivity profiles. This would enable early treatment of imminent septic episodes with proper empirical systemic antibiotics, without waiting for culture results, thus improving the overall infection-related morbidity and mortality.