Synergistic Effects of Lactic Acid and Sodium Dodecyl Sulfate to Decontaminate Escherichia coli O157:H7 on Cattle Hide Sections

Abstract

The objective of this study was to investigate the antibacterial properties of chitosan acetate (CA), sodium dodecyl sulfate (SDS), lactic acid (LA) and their synergism when combined against a nontoxigenic strain of Escherichia coli O157:H7. Treatments that significantly reduced the concentration of E. coli O157:H7 in vitro by more than two logs were further investigated using a cattle hide decontamination model. In vitro treatments included CA (1% chitosan in 1% acetic acid vol/vol), SDS (1% vol/vol), SDS (2% vol/vol), LA (1% vol/vol), CA-SDS combination (1% chitosan in 1% acetic acid vol/vol mixed with 1% SDS vol/vol), and LA-SDS combination in two different concentrations (1% LA mixed with 1% SDS vol/vol, and 1% LA mixed with 2% SDS vol/vol). Butterfield's Phosphate Buffer water was used as a control. The antibacterial effect of 1% CA solution alone and in combination with 1% SDS in vitro resulted in a 1.8 and 1.7 log colony-forming units (CFU)/mL reduction, respectively ( p < 0.05). Only 1% LA, 1% SDS, 2% SDS and their combinations resulted in a > 2 log reduction in E. coli O157:H7. On hide sections, both 1% LA-1% SDS and 1% LA-2% SDS combinations significantly ( p < 0.05) reduced E. coli O157:H7 concentration by 4.6 and 4.7 log CFU/ cm 2 greater than the control, respectively. There was no significant difference in the antibacterial effect of 1% LA compared to the control, 2% SDS compared to the control, or 1% LA compared to 2% SDS. Hence, the antibacterial efficacy of 1% LA against E. coli O157:H7 on hide sections was significantly enhanced when combined with 1% SDS. Results of this study support the use of low concentration LA-SDS combination as a hide wash to reduce the risk of E. coli O157:H7 contamination.

Shiga toxin‐producing Escherichia coli O157, O26 and O111 in cattle faeces and hides in Italy

“…A treatment with hypobromous acid prepared from hydrogen bromide in aqueous solution without subsequent water rinse was tested for reduction of E coli O157:H7 on cattle hide, demonstrating a reduction in prevalence of the pathogen from 25.1 to 10.1 per cent at the concentration of 200 parts per million (ppm) ( Schmidt and others 2012 ). Recently, the synergy of lactic acid and sodium dodecyl sulfate to decontaminate E coli O157 on cattle hides was investigated ( Elramady and others 2013 ). Most of the interventions were studied for E coli O157 inactivation/reduction, but recently Kalchayanand and others (2012) demonstrated that STEC O157 treatments were as effective as for non-O157 STEC.…”

Lactobacillus reuteri suppresses E. coli O157:H7 in bovine ruminal fluid: Toward a pre-slaughter strategy to improve food safety?

“…The efficiency of lactate in inhibiting E . coli O157:H7 multiplication in food products and cattle hides is well documented [ 43 , 44 ]. Furthermore, Ogawa et al .…”

Peri- and Postharvest Factors in the Control of Shiga Toxin-Producing Escherichia coli in Beef

“…Elramady et al (81), using in vitro broth culture and cattle hide model experiments, studied the efficacy of chitosan acetate (CA), sodium dodecyl sulfate (SDS), and LA as individual treatments and in combination against E. coli O157:H7. CA is a naturally occurring substance with demonstrated antibacterial properties, and SDS is a food additive that has been shown to enhance the antibacterial effects of organic acids, hence the reason for being tested in this study.…”