Immunomodulatory and microbial effect of Lactobacillus Casei against Escherichia coli infection in Wistar Albino rats

Abstract

Microorganisms such as Lactobacillus casei has been extensively studied for its probiotic effects. This bacterium produces lactic acid, antimicrobial peptides, such as bacteriocins, which inhibit the colonization and growth of pathogenic bacteria such as Escherichia coli. Twenty (20) Wistar albino rats which were used and shared into five groups: The Control, infected (Escherichia coli-infected), Probiotic (Escherichia coli-treated), Prophylactic (exposed to Lactobacillus casei, next infected with Escherichia coli), Antibiotic (ciprofloxacin-treated). At 0, 7, 14 and 21 days, body temperature, weight and faecal samples were collected. While at day 21 (the end of the experiment), blood samples and organs (liver and colon) were collected for hematological analysis and microbial analysis of organ samples respectively. All the groups had temperature range from 36 - 36.3 ^oC at day 0. At day 14 and 21, all the groups had an increase in temperature, though, there was no statistical difference among the groups with respect to temperature (p>0.05). At day zero (0), the body weight of the experimental animals was within the ranged 150.7 - 191.4 g. The experimental animals in group B had a decline in body weight from 191.4 g at day 0 to 170 g at day 21. While group C wistar rats had an average body weight of 150.7 g at day 0, 169 g at day 7, 156 g at day 14 and a sharp body weight increase of 198 g at day 21 (the end of the experiment). The White blood cells (WBC) range from 8.8±0.7-14.7±4.6 10³/µL and there was statistical difference in WBC counts within the groups (p = 0.02). The red blood cells (RBC) ranged from 5.2±2.410⁶/µL for group D to 7.0±0.3 10⁶/µL for group A. For hemoglobulin (HGB), group C and D had the lowest of 14.0±1.6 g/dL and group A recorded the highest of 15.8±0.7 g/dL (p = 0.08). This results highlighted that probiotic (Lactobacillus casei) did not only exhibited antagonistic activities against E. coli but also positively have effect on hematological indices which possibly reflect and also enhanced immune response.