Abstract

Opportunistic skin infections, which disrupt skin barriers in immunocompromised patients, cause over 50,000 deaths annually worldwide. With the rise of multidrug-resistant bacteria, medical facilities, pharmaceutical companies, and governments urgently seek solutions. Therefore, this study evaluates the antibacterial effects of Aloe Vera gel solution (AGS) and Kefir milk supernatant (KMS) against opportunistic bacteria causing skin infections. Preidentified bacterial cultures were obtained from a lab, and were confirmed through Gram staining, biochemical assays (TSI, citrate utilization, urease, nitrate reductase), tube coagulase, catalase, and oxidase tests. AGS was prepared by mixing 1 mL of gel with 8 mL of sterile water, while KMS was obtained by fermenting kefir grains in milk centrifuging 5mL kefir and collecting the supernatant. Antimicrobial testing was conducted using Mueller-Hinton agar, with bacterial lawns matched with 05% McFarland standards exposed to 0.1 mL of AGS and KMS for 24 hours at 37°C, after that inhibition zones were measured. Gram-positive organisms included Staphylococcus aureus, Streptococcus pyogenes, and Bacillus subtilis, Corynebacterium diphtheriae and Staphylococcus epidermidis, while gram-negative microbes included Citrobacter freundii, Escherichia coli, Enterobacter aerogenes, Klebsiella oxytoca, Proteus mirabilis, Morganella morganii, and Pseudomonas aeruginosa. The antimicrobial assay revealed that KMS exhibited effectiveness against Streptococcus pyogenes, Enterobacter aerogenes, Escherichia coli, and Providencia stuartii as indicated by inhibition zones of 19 mm, 15 mm, 13 mm, and 12mm respectively. AGS demonstrated antimicrobial activity against Bacillus subtilis, Providencia stuartii, and Staphylococcus aureus, with inhibition zones of 15 mm, 20 mm, and 15 mm, respectively. However, both KMS and AGS were found to be ineffective against Staphylococcus epidermidis, Pseudomonas aeruginosa, Klebsiella oxytoca, Citrobacter freundii, Corynebacterium diphtheriae, Proteus mirabilis, and Morganella morganii. The study demonstrates that KMS and AGS significantly inhibited skin opportunistic pathogens. Future research should optimize dosages to augment the efficacy and investigate the potential synergistic effects for resistant pathogens.

Keywords: Opportunistic pathogens, skin infections, Kefir Extract, Aloe Vera gel, Antibiotic resistance