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 can act as reservoirs of antibiotic resistance genes, acquiring or transferring them to other microorganisms. The review focuses on LAB group of dairy origin (Lactobacillus, Lactococcus, Streptococcus, Leuconostoc, Pediococcus and Weissella) and Bifidobacterium genus, considering its large use in dairy industry. We have analyzed data in the last 25 years, highlighting atypical resistance, genetic traits correlated to antibiotic resistance and their ability to be transmitted to other microorganisms; comparative analysis of resistomes was also considered. Differences were observed among wild strains isolated from different regions because of authorized antibiotic use. Com-mercial strains belonging to Lactobacillus, Streptococcus and Bifidobacterium currently used for industrial dairy products are frequently resistant to gentamycin, kanamycin, chloramphenicol together with tetracycline. The presence of resistant wild LAB in raw milk products has been significantly reduced as a result of worldwide restrictions on the use of antibiotics in animal husbandry. Transmissible resistances are still present in industrial cultures, despite the great effort of starter industries in the process control and the safety screening of commercial cultures.

Automated summary

Antibiotic resistance is a growing concern for public health and the global economy. Lactic acid bacteria (LAB) commonly found in dairy products and agro-zootechnical environments can serve as reservoirs for antibiotic resistance genes, which can be acquired or transferred to other microorganisms. This review focuses on LAB and Bifidobacterium species used in the dairy industry, analyzing data from the past 25 years to identify atypical resistance, genetic traits related to antibiotic resistance, and their potential to be transmitted to other microorganisms. Comparisons of resistomes were also conducted. The presence of antibiotic-resistant LAB in commercial dairy products has decreased due to worldwide restrictions on antibiotic use in animal husbandry, but transmissible resistances still exist in industrial cultures.