Antibiotic resistance and probiotics properties of lactic acid bacteria isolated from Andean vegetable and animal products

Abstract

In Andean regions of America, many traditional fermented foods and beverages are produced. Vegetable traditional products involve quinoa and amaranth whose widespread consumption as grains and fermented flours (sourdoughs) has grown recently due to their high nutritional value and lack of gluten. Fermented potatoes (Tocosh) have also been produced from ancient times in the Central Andean region of Peru, whereas llama meat fermented sausages are traditionally produced and consumed in Northwestern Argentina. At present, there is great concern that commensal bacterial populations from food and the gastrointestinal tract (GIT) of humans and animals, such as lactic acid bacteria (LAB) can serve as reservoir for antibiotic resistance genes, which can be horizontally transferred to other microorganisms. On these bases, the antibiotic resistance profiles (EFSA-2012) of eighty LAB strains isolated from Andean products were investigated. The analyzed exhibited a general sensitive profile against ampicilline (AMP), vancomycin (VAN), gentamycin (GEN), kanamycin (KAN), streptomycin (STR), erythromycin (ERY), clindamycin (CLI), tetracycline (TET) and chloramphenicol (CHL). Several strains were resistant mainly to the aminoglycosides (KAN, STR and GEN) while a multi-resistant pattern was found particularly among strains isolated from quinoa /amaranth grains and sourdoughs. However, sensitive LAB strains were observed among Lb. sakei, Lb. reuteri, Lb. plantarum, Lb. casei and Leuc. mesenteroides. On the other hand, to select LAB strains with probiotic potential the resistance to stress factors (lysozyme, bile salts and low pH) present in the GIT, surface properties (hydrophobicity, autoaggregation and adhesion to caco-2 cells) and production of antimicrobial compounds were evaluated. Results allowed selecting Lb. plantarum (2 strains), Lb. reuteri (1) and Lb. casei (1) as the best candidates to be used as probiotics.