Diversidade e resistência antimicrobiana de bacterias ácido láticas de leite caprino no semiarido Paraibano

Abstract

Lactic acid bacteria (LAB) are non-pathogenic bacteria derived from milk and have significant technological potential due to their broad applicability. Although considered beneficial bacteria, LAB can present different antimicrobial susceptibility profiles due to the diversity of their genera. This study aimed to identify the taxonomy of LAB isolated from raw milk of goats raised in the Caatinga biome and to evaluate their antimicrobial susceptibility. Milk was collected from six different farms and plated on MRS and M17 agars, followed by incubation. Presumptive colonies were isolated and subjected to confirmatory tests such as catalase and Gram stains. Confirmation was performed by MALDI-TOF, followed by antibiogram by the Kirby-Bauer technique, using commercial discs containing sulfazotrim 25 mcg, ceftazidime 30 μg, oxacycline 1 μg, gentamicin 10 μg, ciprofloxacin 5 μg, clindamycin 2 μg, penicillin 10 IU, vancomycin 30 μg, erythromycin 15 μg, tetracycline 30 μg, chloramphenicol 30 mcg and amikacin 30 mcg. Of the 28 isolated strains, 17 were identified as Lactococcus spp. (12 L. lactis and 5 L. garvieae) and 11 Enterococcus spp. (3 E. faecium, 4 E. durans, 3 E. faecalis and 1 E. hirae). Antimicrobial resistance was observed in 24.8% of Enterococcus spp. bacteria and only 8% of Lactococcus spp. bacteria. These results contribute to our understanding of the microbiota of goat milk produced in the Caatinga biome, both from the perspective of its biotechnological potential and the potential risks associated with antimicrobial resistance, particularly in Enterococcus spp.