The Impact of Melaleuca leucadendron and Eucalyptus camaldulensis Essential Oils in Combination with Norfloxacin on Antibiotic-Resistant Salmonella spp. Isolated from Chickens
The Impact of Melaleuca leucadendron and Eucalyptus camaldulensis Essential Oils in Combination with Norfloxacin on Antibiotic-Resistant Salmonella spp. Isolated from Chickens
Nguyen Van Vui1*, Ly Thi Thu Lan2, Nguyen Van Tung Lam3, Huynh Thanh Tan1
ABSTRACT
The overuse of antibiotics in livestock production has contributed to the rise of antibiotic-resistant bacteria, posing a significant risk to both animal and human health. Essential oils from Melaleuca leucadendron and Eucalyptus camaldulensis contain bioactive compounds with bactericidal properties. This study aimed to assess their effectiveness, both individually and in combination with norfloxacin, against antibiotic-resistant Salmonella spp. isolated from diseased chickens. Antibiotic susceptibility of the bacterial isolates was evaluated using the disk diffusion method, while their bactericidal activity was determined by measuring the minimum bactericidal concentration (MBC). The interaction between essential oils and antibiotics was assessed using the fractional bactericidal concentration index through a microdilution checkerboard assay. Salmonella typhimurium and Salmonella enteritidis were isolated from infected chickens, showing notable resistance to ampicillin, streptomycin, and colistin. The MBC of Melaleuca leucadendron essential oil was 13,000 µg/ml, whereas Eucalyptus camaldulensis exhibited a higher MBC of 20,000 µg/ml. When combined with norfloxacin, both essential oils demonstrated a synergistic effect, significantly enhancing bacterial eradication. These findings highlight the potential of using Melaleuca leucadendron and Eucalyptus camaldulensis essential oils alongside norfloxacin to combat antibiotic-resistant Salmonella spp. in poultry. The study suggests that integrating essential oils into treatment strategies could improve antibiotic efficacy and help mitigate resistance in livestock.
Keywords | Melaleuca leucadendron, Eucalyptus camaldulensis, Antibiotic-resistance, Salmonella spp., Synergistic, Antibacterial
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June 2025
Adv. Anim. Vet. Sci., Vol. 13, Iss. 6,
