SAFETY CHARACTERIZATION OF Lactobacillus STRAINS

FABERSANI, EMANUEL; RUSSO, MATIAS IRINEO; MEDINA, ROXANA BEATRIZ; ABEIJON MUKDSI, MARIA CLAUDIA; GAUFFIN CANO, MARIA PAOLA

San Miguel de Tucumán

Congreso; XII Congreso Argentino de Microbiología General; 2017

Sociedad Argentina de Microbiología General (SAMIGE)

A wide variety of microbial species is used in food and feed production worldwide. Some have a history of safe use while others are less well understood and their use may represent a risk for consumers. Probiotics are live microorganisms which, administered in adequate amounts, exert a beneficial effect on the health of the host. Taking into account the worldwide obesity epidemic and the importance of using new probiotic strains for this disease, our working group selected strains which showed probiotic effects in animal models of diet-induced obesity. The study of beneficial properties attributed to isolated microorganisms constitutes a field of interest for the development of functional foods. A fundamental requirement that contributes to the development of these foods is to determine the degree of food safety of probiotic strains before they are marketed. Lactobacilli are generally regarded 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 their presence in the human intestinal tract. However, certain Lactobacillus strains have been associated with cases of sepsis, endocarditis, or bacteremia, mostly in association with a severe underlying disease. On the other hand, the absence of acquired antimicrobial resistance is an important criterion for evaluating the safety of lactic acid bacteria used as food started or probiotics. The aim of this study was to evalue the safety of strains with probiotic potential in obesity: Lactobacillus casei CRL431, Lactobacillus fermentum CRL1446, Lactobacillus plantarum CRL353 y Lactococcus lactis 1434. Our workgroup has assessed many functional properties of this Lactobacillus strains, but parameters regarding safety must be studied before calling them probiotics. In this work, safety aspects of Lactobacillus strains were studied. None of the strains tested caused a- or b-hemolysis. All the strains were susceptible to tetracycline, clindamycin, streptomycin, ampicillin, erythromycin, kanamycin, gentamicin, vancomycin and chloramphenicol. We also did not find antibiotic resistance genes for any of the strains studied. Mice treated daily with an oral dose of 108 CFU during 21 days showed no signs of pain, lethargy, dehydration, or diarrhea, and the histological studies were consistent with those findings. No translocation of microorganisms to blood, spleen, or liver was observed. Regarding these findings, Lactobacillus casei CRL431, Lactobacillus fermentum CRL1446, Lactobacillus plantarum CRL353 y Lactococcus lactis 1434 strains are microorganism GRAS with a great potential as probiotic for obesity.