A rare case of equine Haemotropic Mycoplasma infection in Nigeria

Abstract

Equine haemotropic mycoplasmosis (EHM) is a condition rarely reported worldwide. A horse presented with unspecific clinical findings and non-response to treatment to the common and endemic haemoparasitic and bacterial infections, warranted a thorough molecular investigation of suspected haemoparasitic infection given the fluctuating parasitaemia and the low sensitivity and specificity of Light Microscopy (LM) detection of haemoparasitic infections. Blood collected from an adult horse, domiciled at the University of Ibadan Veterinary Teaching Hospital, Ibadan, Nigeria was screened by LM and PCR techniques for haemo-parasites. The 16S rRNA gene of pan-Hemoplasma spp was targeted amplified and sequenced using Sanger automatic sequencing techniques. This case shows the very first molecular evidence of EHM in Africa and Nigeria, and the third case in the World. Microscopic examination of the horse’s blood smear presented with signs of lethargy, inactivity, anorexia and moderate emaciation, showed numerous coccoid-shaped epierythrocytic parasites. Subsequent 16S rRNA sequence data and phylogenetic analyses confirmed the presence of a haemotropic mycoplasma (‘Candidatus M. haemocervae’–like) in the horse. The hemoplasma sequence obtained falls in the same clade with some Candidatus Mycoplasma haemocervae sequences with which it shared more than 98.7% homology. This finding suggests that horses in this geographical region may also be suffering from EHM and calls for the need of epidemiological surveillance of equine hemoplasmosis with emphasis on their clinical, economic, performance and zoonotic implications in the sub-region.

Keywords: Nigeria, Horse, Haemotropic mycoplasma, ‘Candidatus M. haemocervae’–like