A Study on Molecular Epidemiology of Brucella Species Isolated in Sudan and Exploring Knowledge, Attitudes and Practices Related to Acquisition of Brucellosis

Abstract

The objectives of this study were to identify biotypes and genotypes of Brucella organisms isolated from Sudan and to assess participants’ knowledge, attitude and practices (KAP) related to the transmission of brucellosis to animals and humans in Khartoum state. Convenient sampling was performed (March-December, 2015) to select the study subjects based on sero-positivity for brucellosis and consent. Fourteen Brucella cultures were isolated from 541 milk of sero-positive cows representing 127 dairy herd from Khartoum state. Further six Brucella strains (three Brucella abortus and biovar 1, 3, 6 three Brucella melitensis biovar 1, 2 and 3) identified at the Brucella Unit/ Central Veterinary Research laboratories (CVRL) –Soba in (2005-2014)were inculded in the study. Brucellae from this study along with the CVRL strains were used to identify the genotypes of Brucella in Sudan. The study also involved filling a structured-questionnaire by interviewing 150 farmers and workers about their KAP related to brucellosis. Molecular characterization of Brucella organisms was performed using the Brucella species-specific Bruce-ladder PCR. Seventeen B. abortus strains and three B. melitensis strains were confirmed, while the AMOS-PCR, among all, identified the three B. melitensis strains and only two of the B. abortus strains as S19 vaccine strain. These 20 Brucella strains in this study were genotyped by the multiple-locus variable number tandem repeats (VNTR) analysis (MLVA16) scheme. Five genotypes (GTs) within panel1 (MLVA8) and six GTs within panel2A (MLVA11) and thirteen GTs within the MLVA16 were revealed including ten B. abortus GTs and three B. melitensis GTs. The B. abortus strains from Sudan (n=17) grouped in closely related small clusters of identical genotypes with other strains from Africa like Nigeria, Tchad, Kenya, Uganda, Morocco, Algeria and other continents like Brazil, Portugal, Spain and Syria. B. melitensis bv 1 strain in this study clustered with the American group of B. melitensis, and B. melitensis bv 2 and 3 clustered with the East Mediterranean group of B. melitensis and all Sudan strains were new genotypes. B. abortus GTs circulating in livestock from Sudan in the current study are closely related to GTs from neigbouring countries, which indicate possible spread of brucellosis between Sudan and these countries. Furthermore, B. melitensis GTs in this study sharing genetic bonds with B. melitensis GTs from United Arab Emirates and Somalia. On the other hand, analysis of KAP relating to brucellosis revealed low and poor understanding of the zoonotic nature of the disease. Based on the findings of our and previous studies, it seems that the B. abortus bv 6 is the predominant cause of bovine brucellosis in this country, and that brucellosis might have spread between Sudan and neighboring countriess. The study recommends a countrywide surveillance to isolate and genotype circulating Brucella strains to have further insight on brucellosis in Sudan. Bruce-ladder PCR would be better option for characterization of Brucella in Sudan, as the AMOS PCR could not identify most of the B. abortus strains that predominant in Sudan. Awareness of stakeholders about brucellosis and people in contact should be raised. We believe that the findings of this study can contribute to and promote brucellosis control in Sudan.