Effect of probiotic mixture on some haematological parametres in Escherichia coli O157:H7 experimentally infected Yankassa lambs

Abstract

This study was designed to determine the effect of probiotics mixture on some haematological parameters in lambs experimentally infected with Shiga-toxin Escherichia coli (STEC) O157:H7. Fifteen Yankassa breed of lambs aged between 3-4 weeks old were used. The lambs were divided into three groups of five lambs each (n=5). Group A: Neither probiotics nor STEC O157:H7 were administered as they served as the control, Group B: lambs were administered viable STEC O157:H7 cells at 6X108CFU/ml in 1ml normal saline together with daily administration of a mixture of probiotics (Lactobacillus acidophilus, Bacillus pumilus, Bacillus subtilis and Bacillus licheniformis) at 4.5 x10 CFU/ml, Group C: lambs were administered only viable STEC O157:H7 cells at 6x108 CFU/ml without probiotics. Both the mixtures of probiotics and STEC O157:H7 cells were mixed in 1ml of normal saline and administered orally to the lambs. Following oral inoculation of the lambs with STEC cells, blood samples were collected once weekly for six weeks: blood samples were collected for the determination of total white blood cell count (TWBCC) and differential counts. The mean TWBCC, neutrophil and lymphocyte counts of groups B and C lambs rose significantly (P<0.05) in the first week post infection and gradually decreased during the period of study. However, the values of the mean TWBCC, neutrophil and lymphocyte counts of Group C lambs were significantly higher (P<0.05) than that of groups A and B lambs over the six weeks period. There was no significant difference in the mean absolute eosinophil and monocyte counts among the three experimental groups. In conclusion, lower values of mean TWBCC, neutrophil and lymphocytes was observed in the lambs administered probiotics mixture as compared to the lambs that did not receive probiotics mixture. This was possibly due to the lower level of infection in those groups of lambs as a result of the probiotics administered. It was therefore recommended that probiotics should be administered to lambs to help control STEC O157:H7.

Keywords: Shiga-toxin producing Escherichia coli, Total white blood cells, Lymphocytes, Neutrophils, Probiotics, Yankassa lambs