In Vitro Characterization of Indigenous Probiotic Strains Isolated from Colombian Creole Pigs.

Three lactic acid strains were isolated from feces of the native Zungo Pelado breed of pigs ( = 5) and presumably identified as belonging to the family by morphological techniques showing that they were Gram-positive/rod-shaped and catalase- and oxidase-negative. They were then identified by biochemical tests using API 50CHL as (CAM6), (CAM7), and (CL4). However, 16S rRNA identification showed that all three strains were . Additionally, all three isolates were able to grow in pH 3 and 4. Interestingly, the growth of the CAM7 strain decreased at pH 5.6 compared to that of the CAM6 strain ( < 0.05), and the growth of the CL4 strain was reduced at pH 7( < 0.05). All three candidates showed good growth on bile salts (≥0.15%), and CAM6 and CAM7 showed better tolerance at higher concentrations (0.30%). Similarly, all strains tolerated sodium chloride (NaCl) concentrations from 2 to 10%. These strains also grew well at all temperatures tested (30, 37, and 42 °C). The CAM6 strain showed in vitro antibacterial activity against selected enteropathogenic bacteria ( strain NBRC 102203 and serovar Typhimurium 4.5.12) and commensal bacteria ( ATCC BAA-1705D-5 and ATCC 15442) and resistance to all antibiotics except amoxicillin. Further studies to evaluate the effects of these probiotic candidate strains in commercial pigs are currently underway.