| Summary: | Three lactic acid strains were isolated from feces of the native Zungo Pelado breed of pigs (<i>n</i> = 5) and presumably identified as belonging to the <i>Lactobacillaceae</i> 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 <i>Lactobacillus plantarum</i> (CAM6), <i>Lactobacillus brevis</i> (CAM7), and <i>Lactobacillus acidophilus</i> (CL4). However, 16S rRNA identification showed that all three strains were <i>Lactobacillus plantarum</i>. 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 (<i>p</i> < 0.05), and the growth of the CL4 strain was reduced at pH 7(<i>p</i> < 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 (<i>Escherichia coli</i> strain NBRC 102203 and <i>Salmonella enterica</i> serovar Typhimurium 4.5.12) and commensal bacteria (<i>Klebsiella pneumoniae</i> ATCC BAA-1705D-5 and <i>Pseudomonas aeruginosa</i> 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.
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