The in vitro Effect of Heat, Lactic Acid-Silver Nanoparticle Combination on Shiga Toxigenic Escherichia coli

Abstract

Lactic acid and silver nanoparticle compositions’ effects as antimicrobial to reduce Shiga Toxigenic Escherichia coli (STEC) contamination were studied in vitro conditions. Four silver nanoparticle sizes, 20, 40, 100, 150 nm with lactic acid (LA) solutions of 1.5%, 2%, 2.5%, were applied and heated in a water bath to 20°C, 40°C and 50°C. Shiga toxigenic E. coli O26, O103, O111, O145 and O157 were used as control microorganism. Microbial counts were analyzed using a general linear model univariate test. According to our results, 20, 100, and 150 nm Ag Nanoparticles (AgNPs) in 2% and 2.5% LA density at 40 °C and 50 °C have a decrease of 3 log₁₀ CFU/ml and more. The highest antimicrobial effect was seen at 150 nm AgNP, 2.5% LA at 50°C. Our findings show that AgNP combined with lactic acid can be a low-cost reduction method and promise a novel antimicrobial agent.