The effect of oral administration Lactococcus lactis probiotic vaccine carrying Brucella abortus BLS antigen on changes in blood leukocyte ratio and CRP as biomarkers in brucellosis

Abstract

Introduction: Oral vaccines in infectious diseases, whose agents enter the body through the mucous membrane, will induce the innate immune pathway. The neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) have been documented as biomarkers of Brucella systemic inflammation. The purpose of this study is to investigate the effect of oral administration of the Lactococcus lactis probiotic vaccine carrying Brucella abortus BLS antigen on the ratio of blood leukocytes as biological biomarkers in mice with brucellosis compared to the control group. Materials and Methods: 60 mice with brucellosis (challenged) and 60 healthy mice (non-challenged) were included in the study. The challenge group was divided into 6 subgroups and 6 types of intervention including 1) L. lactis/pNZ8148-Usp45-BLS, 2) L. lactis-pNZ8148, 3) L. lactis, 4) IRIBA Vac, 5) pNZ8148 and 6) PBS received by gastric gavage in all groups except IRIBA Vac. Serum was used to check hematological parameters. C-reactive protein (CRP) level was measured. The number of neutrophils and lymphocytes was determined using a complete blood cell count. PLR and NLR were calculated. Results: In this study, the level of CRP in the mice of the challenge group increased significantly compared to the non-challenge group. (P