Antibiotic resistance in wild and commercial non-enterococcal Lactic Acid Bacteria and Bifidobacteria strains of dairy origin: An update

Antibiotic Resistance is a growing concern for public health and global economy. Lactic acid bacteria (LAB)involved in the production of dairy products and commonly present in the agro-zootechnical environment canact as reservoirs of antibiotic resistance genes, acquiring or transferring them to other microorganisms. Thereview focuses on LAB group of dairy origin (Lactobacillus, Lactococcus, Streptococcus, Leuconostoc, Pediococcusand Weissella) and Bifidobacterium genus, considering its large use in dairy industry. We have analyzed data in thelast 25 years, highlighting atypical resistance, genetic traits correlated to antibiotic resistance and their ability tobe transmitted to other microorganisms; comparative analysis of resistomes was also considered. Differenceswere observed among wild strains isolated from different regions because of authorized antibiotic use. Commercialstrains belonging to Lactobacillus, Streptococcus and Bifidobacterium currently used for industrial dairyproducts are frequently resistant to gentamycin, kanamycin, chloramphenicol together with tetracycline. Thepresence of resistant wild LAB in raw milk products has been significantly reduced as a result of worldwiderestrictions on the use of antibiotics in animal husbandry. Transmissible resistances are still present in industrialcultures, despite the great effort of starter industries in the process control and the safety screening of commercialcultures.