SAFETY CHARACTERIZATION OF Lactobacillus STRAINS

EMANUEL FABERSANI; MATIAS I. RUSSO; ROXANA MEDINA; CLAUDIA ABEIJÓN MUKDSI; PAOLA GAUFFIN CANO

San Miguel de Tucumán - Tucumán

Congreso; XII Congreso Argentino de Microbiología General SAMIGE; 2017

Asociación Civil de Microbiología General

A wide variety of microbial species is used in food and feed production worldwide. Some have ahistory of safe use while others are less well understood and their use may represent a risk forconsumers. Probiotics are live microorganisms which, administered in adequate amounts, exert abeneficial effect on the health of the host. Taking into account the worldwide obesity epidemic and theimportance of using new probiotic strains for this disease, our working group selected strains whichshowed probiotic effects in animal models of diet-induced obesity. The study of beneficial propertiesattributed to isolated microorganisms constitutes a field of interest for the development of functionalfoods. A fundamental requirement that contributes to the development of these foods is to determinethe degree of food safety of probiotic strains before they are marketed. Lactobacilli are generallyregarded as safe (GRAS) and most of them are included in the Qualified Presumption of Safety (QPS)list of the European Union due to the long history of use in fermented dairy products and theirpresence in the human intestinal tract. However, certain Lactobacillus strains have been associatedwith cases of sepsis, endocarditis, or bacteremia, mostly in association with a severe underlyingdisease. On the other hand, the absence of acquired antimicrobial resistance is an important criterionfor evaluating the safety of lactic acid bacteria used as food started or probiotics. The aim of this studywas to evalue the safety of strains with probiotic potential in obesity: Lactobacillus casei CRL431,Lactobacillus fermentum CRL1446, Lactobacillus plantarum CRL353 y Lactococcus lactis 1434. Ourworkgroup has assessed many functional properties of this Lactobacillus strains, but parametersregarding safety must be studied before calling them probiotics. In this work, safety aspects ofLactobacillus strains were studied. None of the strains tested caused a- or b-hemolysis. All the strainswere susceptible to tetracycline, clindamycin, streptomycin, ampicillin, erythromycin, kanamycin,gentamicin, vancomycin and chloramphenicol. We also did not find antibiotic resistance genes for anyof the strains studied. Mice treated daily with an oral dose of 108 CFU during 21 days showed nosigns of pain, lethargy, dehydration, or diarrhea, and the histological studies were consistent withthose findings. No translocation of microorganisms to blood, spleen, or liver was observed. Regardingthese findings, Lactobacillus casei CRL431, Lactobacillus fermentum CRL1446, Lactobacillusplantarum CRL353 y Lactococcus lactis 1434 strains are microorganism GRAS with a great potentialas probiotic for obesity.