Therapeutic efficacy of Lactobacillus acidophilus against bacterial isolates from burn wounds

Background: Probiotics are live microorganisms which are mainly strains of Lactobacillus spp., Bifidobacterium spp. When administered in adequate amounts, these microorganisms offer a health benefit for the host. Probiotic organisms are also available commercially in milk, sour milk, ice cream and other foods.

Aims: To identify bacterial species isolated from burn wounds, and also to evaluate (In-vitro) the therapeutic efficacy of Lacto. acidophilus against these bacterial isolates. To compare this activity to other antibacterial agents which are used medically in the treatment of burn wound cases.

Materials and methods: Burn wound swabs were obtained from 50 patients who had been admitted to hospitals in Baghdad during August to November 2009. These swabs were inoculated onto enriched and differential culture media. Subcultures were performed on selective media. The necessary biochemical tests were conducted and the organisms identified using standard procedures. Susceptibility of isolated pathogens to local isolates Lacto. Acidophilus (with 1×10(8) cells/mL) and 10 commonly used burn wounds antibiotics was examined using standard susceptibility testing.

Results: Ninety different organisms were isolated. Gram-positive cocci accounted for 16 (17.7%) and gram-negative bacilli for 74 (82.2%) bacterial isolates. Pseudomonas aeruginosa 30(33.3%) were the most commonly isolated organisms, followed by Escherichia coli, Enterobacter spp., Klebsiella spp., Proteus spp.(22.2,20,4.4,2.2%), respectively. Staphylococcus aureus isolates were performed in 8(8.8%). However, the incidence of Staphylococcus epidermidis was 2 (2.2%), while ß-haemolytic Streptococci was 4(4.4%). In susceptibility testing, Lacto. acidophilus had coverage against 90 (100%) of 74 gram-negative and 16 of gram-positive bacteria tested. The coverage of the remaining 10 antibacterial agents used was different in their activity (resistance or sensitivity), which ranged between 50-100%.

Conclusion: The results of the study concluded that lactobacillus acidophilus concentration of 1×10(8) cells/mL had a high activity to inhibit the growth in-vitro of all pathogenic gram-positive and gram-negative bacteria, which cause burn wound infections. This indicated the therapeutic efficacy of lactobacillus acidophilus bacteria.