Phylogenetic characterization of hemotropic Mycoplasma in a buffalo calf with acute hemolytic crisis and co-infections from India

Abstract Background Arthropod-borne pathogens, particularly hemotropic Mycoplasma species, are well documented in cattle; however, their occurrence and clinical relevance in buffaloes remain poorly understood. This report describes the molecular detection and phylogenetic characterization of “ Candidatus Mycoplasma haematobovis ” in a buffalo calf presenting with acute hemolytic crisis and anemia, concurrently infected with Theileria spp. and Anaplasma/Ehrlichia spp. Results A three-month-old female buffalo calf was referred to the ruminant medicine unit with a history of hyporexia, weakness, and one-day history of coffee-colored urine. Clinical evaluation and laboratory investigations, including complete blood count, blood smear, fecal examination, serum phosphorus and creatinine estimation, and PCR screening for common vector-borne pathogens ( Theileria , Babesia , Trypanosoma , Anaplasma/Ehrlichia , and hemotropic Mycoplasma spp.) was conducted. The findings revealed severe anemia with polychromasia and anisocytosis, mildly elevated creatinine, and hemoglobinuria, consistent with acute hemolysis. PCR confirmed co-infections with Theileria , Anaplasma/Ehrlichia , and hemotropic Mycoplasma . Sequencing confirmed the hemoplasma as “ Candidatus M. haematobovis ” , an emerging multi-host pathogen rarely reported from tropical India, with the sequence deposited in GenBank (accession no. PX208924). Phylogenetic analysis showed close genetic relatedness to isolates from diverse host species worldwide. A therapeutic regimen comprising diminazene aceturate, oxytetracycline, and supportive treatment was provided. Conclusions These findings underscore the pathogenic potential of “ Candidatus M. haematobovis ” in buffaloes, particularly under concurrent hemoparasitic infections, and highlight the need for advanced molecular diagnostics and integrated vector control strategies.