Aims
The aim of this study was to analyse the current situation of Contagious Bovine Pleuropneumonia (CBPP) in the Central African Republic (CAR) by seroprevalence analysis, as well as isolation and characterization of strains of the etiologic agent, Mycoplasma mycoides mycoides (Mmm), circulating in livestock breeding regions. Material and
Conclusion
CBPP is enzootic in the CAR in spite of control campaigns based on use of the live T1 vaccines, which have shown little efficacy due to poor implementation in the field. New strategies combining controlled use of antibiotics and inactivated vaccines, with increased thermostability, should be well received by livestock keepers and allow a better control of CBPP in the region. The fact that the recent Mmm isolates are still resistant to tetracycles is encouraging. Matériel et méthodes: La situation de la péripneumonie contagieuse bovine en République centrafricaine (RCA) a été analysée par une enquête sérologique sur 776 sérums, à l'aide de la technique cELISA. La prévalence de la maladie a été estimée à 12,5% quelle que soit la région. Résultats: Une différence significative a été observée entre les zébus et la race taurine, probablement associée au mode d'élevage, favorisant plus ou moins les contacts. La présence de la maladie dans les trois régions d'élevage a également été confirmée par l'isolement de souches de Mycoplasma mycoides mycoides lors de foyers de 2019. Ces souches sont toujours sensibles aux tétracyclines. Les trois souches dont le génome a été séquencé étaient strictement identiques. Replacés dans un arbre phylogénétique, ces génomes sont proches de ceux des souches isolées précédemment en RCA, ce qui montre que la maladie y est enzootique. Conclusion: L'amélioration de la situation ne pourra venir que d'une modification des stratégies de lutte et d'un retour au calme sur le terrain afin de pouvoir les appliquer.
Material and methods
The strains obtained were subjected to whole genome sequencing by Illumina technology and genotyped using the eMLST technique based on 62 genes of the Mmm core genome. Their sensitivity to tetracycline was assessed by determination of the minimum inhibitory concentration (MIC) on agar. A seroprevalence analysis by competitive ELISA was conducted in livestock breeding regions (West, Centre and East CAR), including both zebu and taurine cattle breeds, and both males and females.
Methods
The strains obtained were subjected to whole genome sequencing by Illumina technology and genotyped using the eMLST technique based on 62 genes of the Mmm core genome. Their sensitivity to tetracycline was assessed by determination of the minimum inhibitory concentration (MIC) on agar. A seroprevalence analysis by competitive ELISA was conducted in livestock breeding regions (West, Centre and East CAR), including both zebu and taurine cattle breeds, and both males and females.
Results
The three strains isolated in the three regions of the CAR shared exactly the same genomic sequence. Phylogenetic analysis showed that they were closely related to a strain isolated in the CAR in 1991, also sequenced in this study, and clustered with Mmm strains originating from East and Central Africa. The recent isolates presented increased MIC values, though they were still sensitive to tetracycline. The global CBPP prevalence in the CAR was estimated at 12.5% with no significant differences observed between cattle breeding regions, nor between males and females. However, a significantly higher prevalence was observed in zebu compared to taurine cattle, most likely in relation to their herding system based on cattle transhumance and nomadic pastoralism.