Safety, environmental and technological characterization of beneficial autochthonous lactic bacteria, and their vaginal administration to pregnant cows for the design of homologous multi‑strain probiotic formulas

MARIA HORTENCIA MIRANDA; CECILIA ARISTIMUÑO FICOSECO; MARIA ELENA FÁTIMA NADER

BRAZILIAN JOURNAL OF MICROBIOLOGY

SOC BRASILEIRA MICROBIOLOGIA

Año: 2021 vol. 52 p. 2455 - 2473

1517-8382

In recent years, veterinary probiotic formulations constitute an interesting alternative to the use of antibiotics in animals forhuman consumption, but beneficial microorganisms must meet certain requirements to be included in these products. Theobjective of this work was to evaluate the safety and innocuity of beneficial autochthonous lactic bacteria (BALB) as wellas to determine their beneficial, environmental, and technological characterization. Antibiotic resistance was assayed usingphenotypic and genotypic methodology. A bovine vaginal fluid simulated medium (MSBVF) was designed where growth,pH changes, and expression of beneficial characteristics of lactic bacteria were evaluated; additionally, the optimal cultureconditions in commercial media were determined in order to obtain the highest biomass production of the strains. Finally,the best strains were lyophilized and administered intravaginally to pregnant cows and their permanence in the vagina andadverse effects were evaluated. The results show that most of the strains were resistant to vancomycin, tetracycline, andstreptomycin, with a high sensitivity to ampicillin, gentamicin, and clindamycin. The strains evaluated did not show gelatinaseor hyaluronidase activity; however, 11 strains produced α-type hemolysis. The optimal growth of the microorganismwas obtained in MRS broth, under slight agitation and without pH control. The strains grown in the MSBVF grew well andmaintained the probiotic properties. Animals treated with probiotics bacteria did not show systemic or local inflammation.These strains can be included in a probiotic veterinary product to be applied to different bovine mucosa.