Students' Research Circle    
 
 
Call for papers
The conference
Veterinary Session
Veterinary Jury
Biology Session
Sponsors
Awards-list
Galleries
» Archive
2022
2021
2020
2019
2018
2017
2016
2015
2014
2013
2012
2011
2010
2009
2008
2007
2006
2005
2004
2003
2002
Regulations
Home » Archive

Archive

In Vitro Study of the Effect of a Probiotic Bacterial Strain of Lactobacillus rhamnosus in a Porcine Intestinal Infection Model
Somogyi Fanni - year 5
University of Veterinary Medicine Budapest, Department of Pharmacology and Toxicology
Supervisors: Dr. Orsolya Farkas, Nikolett Palkovicsné Pézsa

Abstract:

Intestinal infections caused by Escherichia coli (E. coli) and Salmonella Typhimurium (S. Typhimurium) are common in pigs kept in large-scale production due to crowding and stress caused by intensive technology. The oxidative stress and impairment of the intestinal barrier function caused by pathogens can lead to reduced production and the development of clinical signs or even death. For many decades, antibiotics were routinely used to prevent these diseases and for growth promotion, and this practice has contributed to the increasing antimicrobial resistance. Nowadays, the European Union strictly regulates the use of antibiotics in veterinary medicine. The need has therefore arisen for alternative agents and nutritional supplements that do not contribute to increased resistance but can have a positive effect on animal health and productivity and help to maintain healthy intestinal barrier function.

Probiotics have been used in veterinary medicine for a long time, but in many cases the exact mechanism of action responsible for their positive effects and the extent of their efficacy are not yet fully understood. In our experiment, we investigated the protective effect of the probiotic bacterium Lactobacillus rhamnosus (L. rhamnosus) in IPEC-J2 porcine intestinal epithelial cells against pathogenic E. coli and S. Typhimurium bacteria.

First, by using Neutral Red assay we determined that L. rhamnosus at a concentration of 10^8 CFU/mL did not affect the viability of IPEC-J2 cells and used this concentration in further experiments. Next, the intracellular redox state of the cells was investigated by DCFH-DA assay, where L. rhamnosus and pathogenic bacteria were added to the cells using three different treatment types (pre-, parallel, and post-treatment). The effect of the probiotic strain on the paracellular permeability of intestinal epithelial cells was tested using the FITC-D fluorescence dye. Finally, preventive effect of L. rhamnosus on the adhesion of pathogenic bacteria to IPEC-J2 intestinal epithelial cells was tested.

The results of our study demonstrate that L. rhamnosus significantly reduces the oxidative stress induced by E. coli and S. Typhimurium in porcine intestinal epithelial cells. It could prevent barrier function damage and inhibits the adhesion of pathogenic bacteria. Further in vitro and in vivo studies are needed to elucidate the processes underlying the positive effect of L. rhamnosus.



List of lectures