Detection of Aerobic Bacterial Isolates from Burn Wound and Their Antibiogram in Rajshahi Medical College Hospital

Background: Burns are one of the most common and devastating form of trauma. Microbial infection is the serious complication of burn wound patients and remains a major cause of mortality and morbidity. Approximately 75% death of burn patients are attributable to wound infection. Infection with antibiotic resistant bacteria have become an increasingly difficult problem in our time. The aim of this study was to detect the aerobic bacteria and their antibiotic susceptibility pattern in burn units. Objective: To isolate and identify aerobic bacterial pathogens and their antibiogram from burn wound infection cases in Rajshahi Medical College Hospital. Material and Method: A cross-sectional type of descriptive study was conducted in Microbiology department of Rajshahi Medical College, Burn and Plastic Surgery department of Rajshahi Medical College Hospital, Rajshahi during the period of January 2022 to December 2022. The specimen (wound swab) was inoculated in blood agar, nutrient agar, MacConkey’s agar and Cetrimide agar media and incubated aerobically at 37˚C for 24 hours. The organisms were isolated and identified by standard microbiological method. Antimicrobial susceptibility test was done by Kirby-Bauer disc diffusion method. Results: Out of the total 290 samples, culture positive cases were 265 (91.38%) and culture negative cases were 25 (8.62%). In all age groups, female were predominant and total number were 163 (56.21%). Maximum 126 cases were found in the age group of 21-30 years where female 81(27.93%) and male 45 (15.52%). Fire burn was the leading source 133 (45.86%) followed by electricity 83 (28.62%), scald 60 (20.69%), chemical agents 09 (3.10%) and others (contact, lightning 0 (173%). Among the culture-positive isolates, Gram-negative organisms were higher (78.39%) then Gram-positive (21.61%). Among 273 isolates, Pseudomonas aeruginosa was the predominant organism which were 147 (53.85%). Other isolates were Staphylococcus aureus 54 (19.78%), Klebsiella spp. 26 (9.52%), Escherichia coli 20 (7.33%), Proteus spp. 12 (4.40%), Acinetobacter spp. 7 (2.56%), Coagulase negative Staphylococci (CoNS) 5 (1.83%) and Enterobacter spp. 2 (0.73%) respectively. Regarding antimicrobial susceptibility test, Gram-negative organisms were highly susceptible to Colistin followed by Imipenem, Meropenem and Amikacin. Most effective drugs for Gram-positive were Vancomycin and Linezolid. Other susceptible drugs against Gram-positive bacteria were Imipenem, Meropenem.  Conclusion: Most of the isolated bacteria were multi-drugs resistant (MDR). Performing antimicrobial susceptibility test helps the physician to select the most appropriate antibiotic for treating burn wound infections.