Lactobacillus acidophilus reduces Listeria monocytogenes infection by inhibiting mitogen-activated protein kinase genes in growing rabbits

ABSTRACT

We aimed to investigate the effect of Lactobacillus acidophilus ACCC11073 on the growth performance, oxidation, inflammation, and mitogen-activated protein kinase (MAPK) family genes of rabbits infected with Listeria monocytogenes (L. monocytogenes) using antibiotic enrofloxacin hydrochloride (EH) as a reference. There were four treatments including negative control, positive control with L. monocytogenes infection on the first day of feeding trial (PC), PC + EH at 40 mg kg−1, and PC + L. acidophilus at 108 CFU kg−1 of diet using 240 weaned growing rabbits. The results showed that L. monocytogenes infection worsened growth performance of rabbits, whereas EH or L. acidophilus supplementation partially recovered body weight gain, but did not reach the levels of the negative control. Listeria acidophilus and EH decreased L. monocytogenes loads in caecum, liver, spleen, and lymph node, serum oxidative markers including diamine oxidase, malondialdehyde, and protein carbonyl, serum IL-1ß, IL-6, and TNF-α. The decreased effects of EH on IL-1ß and TNF-α were more pronounced than that of the probiotic. Treatments EH and probiotic also de-regulated the mRNA levels of MAPK1, 3, 6, and 14. Listeria acidophilus exhibits a similar effect to EH against L. monocytogenes in rabbits, and the regulation on inflammatory process is via MAPK family genes. The results suggest that L. acidophilus can be used as a feed additive against L. monocytogenes infection.(AU)