Antimicrobial and antibiofilm effects of Satureja hortensis L. essential oil against Salmonella isolated from poultry

Background and Aim : Salmonella spp. cause various acute or chronic diseases in poultry. Infected poultry are considered as important reservoir of Salmonella to enter the human food chain Salmonella are isolated from poultry and its products more than any other animal sources. Antimicrobial resistance (AMR) is a global phenomenon leading to emergence of pathogens with resistance to clinically important antibacterial agents. AMR bacteria cause life-threatening illness in humans and pose a significant threat to health and well-being of humans. In United States, almost two million illnesses, ۲۳,۰۰۰ deaths/year, healthcare cost of $۲۰ billion and a productivity loss of $۳۵ billion to the U.S. economy are reported annually. The efficacy of medicating with antibiotics to prevent or treat Salmonella infections in poultry is matter of debate for many years. Prophylactic or therapeutic activity against salmonellae in poultry have been shown. However, due to inconsistent performance and microbial resistance concern, current protocols for poultry salmonellosis does not regularly rely on antibiotics. Using herbal ingredients such as summer savory may be effective in reducing the problem of bacterial resistance. Satureja hortensis L (Summer savory) lacks synthetic chemicals and has no side effects associated with antibiotic use. Summer savory essential oils prevent biofilm formation and do not completely eliminate bacteria; hence, the immune system remains active. The purpose of this study was to investigate the antibacterial and anti-biofilm activity of Summer savory essential oil against Salmonella isolated from poultry.Methods : The essential oil was extracted using a Clevenger apparatus and subsequently its compounds were determined using GC-MS. Antibacterial properties of essential oil were determined by disc diffusion method, MIC and MBC. To evaluate the anti-biofilm properties the Microtiter plate test was used.Results : The inhibition zone diameter in the disc diffusion test were ۳۸±۴ mm which was confirmed by MIC and MBC values. Regarding anti-biofilm activity, the MIC/۲ and MIC/۴ concentration of S. hortensis significantly inhibited biofilm formation of Salmonella.Conclusion : Based on our results, S. hortensis essential oil showed the growth inhibition and bactericidal activity against Salmonella. Moreover, this study demonstrated anti-biofilm activity of S. hortensis essential against Salmonella.

Keywords:

Satureja hortensis L. , Essential oil , Salmonella , Biofilm