Inactivation of Multi-Drug Resistant Non-Typhoidal Salmonella and Wild-Type Escherichia coli STEC Using Organic Acids: A Potential Alternative to the Food Industry

Abstract

Salmonella and Escherichia coli are the main bacterial species involved in food outbreaks worldwide. Recent reports showed that chemical sanitizers commonly used to control these pathogens could induce antibiotic resistance. Therefore, this study aimed to describe the efficiency of chemical sanitizers and organic acids when inactivating wild and clinical strains of Salmonella and E. coli, targeting a 4-log reduction. To achieve this goal, three methods were applied. (i) Disk-diffusion challenge for organic acids. (ii) Determination of MIC for two acids (acetic and lactic), as well as two sanitizers (quaternary compound and sodium hypochlorite). (iii) The development of inactivation models from the previously defined concentrations. In disk-diffusion, the results indicated that wild strains have higher resistance potential when compared to clinical strains. Regarding the models, quaternary ammonium and lactic acid showed a linear pattern of inactivation, while sodium hypochlorite had a linear pattern with tail dispersion, and acetic acid has Weibull dispersion to E. coli. The concentration to 4-log reduction differed from Salmonella and E. coli in acetic acid and sodium hypochlorite. The use of organic acids is an alternative method for antimicrobial control. Our study indicates the levels of organic acids and sanitizers to be used in the inactivation of emerging foodborne pathogens.

Fuertes perfiles de resistencia a antibióticos en Salmonella spp. aislada de carne de res molida en el centro de México

“…Another important finding is the widespread distribution among study isolates of resistance genes against disinfectants of the quaternary ammonium compounds group (qacL, qacE, and qacEdelta-1). These genes encode active efflux factors, (63) and both in this study (supplementary information, Table S2) and previous research, (4) they have been linked to MDR phenotypes since they are usually recruited in integrons with other AMR genes. (64) It is yet to be determined, however, if the intensive use of quaternary ammonium compounds along the food chain favors the acquisition and conservation of integrons with multiple resistance gene cassettes.…”

The Use of Organic Acids (Lactic and Acetic) as a Microbial Decontaminant during the Slaughter of Meat Animal Species: A Review

“…Reference [77] explain that the influence of the steam solution temperature and carcass temperature can also be enhanced by increasing the pressure of the applicator; increasing the application pressure of the organic acid applicator achieved a log reduction of between 1 and 2 logs of aerobic microorganisms in raw meat [34]. This was confirmed by [78,79] where higher pressure yielded better microbial decontamination of Campylobacter on carcass surfaces. It can be accepted that there is no perfect system(s) that could guarantee the total elimination of microorganisms on meat surfaces during slaughter.…”

“…References [71,72,82,83], as well as the study by [79], showed that prolonged usage of specific acids in a food facility may facilitate the development of resistant strains. As there are currently insufficient data available on microorganisms resistant to OAs, this situation should be monitored and controlled.…”

The Effect of Different Organic Acids and Their Combination on the Cell Barrier and Biofilm of Escherichia coli

“…Organic acids have broad-spectrum antibacterial activity and high food safety (GRAS) and are widely used in the food industry as antimicrobial agents [ 13 ]. In addition, organic acids have little impact on the sensory properties of products and are a low-cost, easy-to-apply option in the food industry [ 14 ], where they can be used in animal production, as growth promoters, and in the food industry for the hygiene of equipment directly related to food [ 15 ]. The molecular mechanisms of organic acid inhibition include energy competition, bacterial outer membrane permeabilization, increased intracellular osmotic pressure, and the inhibition of biomolecule synthesis.…”

“…LA is the most widely used GRAS organic acid and can be used for the disinfection treatment of fresh leafy vegetables [ 23 ]. Studies on the inactivation kinetics of E. coli have shown that LA is more effective than AA and has no irritating odor [ 15 ]. BA is commonly used in poultry feed as a substitute for antibiotics in livestock production systems and exhibits better bacteriostatic effects than acetic acid, formic acid, and propionic acid against certain pathogens [ 24 ].…”