Acholeplasma equirhinis sp. nov. isolated from respiratory tract of horse (Equus caballus) and Mycoplasma procyoni sp. nov. isolated from oral cavity of raccoon (Procyon lotor).

The research presents the isolation and identification of two new bacterial species: Acholeplasma equirhinis sp. nov. from the respiratory tract of a horse in the UK and Mycoplasma procyoni sp. nov. from the oral cavity of a North American raccoon in Canada. The newly identified species exhibit distinct phenotypic and genetic traits compared to other known Mycoplasma and Acholeplasma species.

Isolation and Phenotypic Characterization

• The bacterial strains, named Acholeplasma sp. strain N93 from a horse and Mycoplasma sp. strain LR5794 from a raccoon, were both isolated and cultured in laboratory conditions.
• The characterization of both strains was thorough, assessing their growth patterns, metabolic activity, and resistance to penicillin. Both strains were found to be facultative anaerobes, implying they can adapt to environments with or without oxygen.
• Both of them produced acid from glucose but did not hydrolyze arginine and urea. This information provides insight into the metabolic capabilities of these bacteria.
• Both strains were found to grow well under microaerophilic and anaerobic conditions at temperatures of 35-37 degrees Celsius, indicating their preferred growth conditions.
• One unique feature of Acholeplasma strain N93 was that it did not need serum (a blood component) for growth.

Morphological and Molecular Characterization

• Under microscopic evaluation, colonies of both strains displayed a ‘fried-egg’ appearance which is characteristic of mycoplasma bacteria.
• Further examination through transmission electron microscopy revealed the typical cellular morphology of mycoplasma.
• Genetic analysis of several loci of these new species showed the closest relation to specific established Mycoplasma and Acholeplasma species (A. hippikon and A. equifetale for Acholeplasma N93; M. molare and M. lagogenitalium for Mycoplasma LR5794).
• However, despite these genetic similarities, both novel isolates were unique, having certain genetic markers that differentiated them from previously known Mycoplasma and Acholeplasma species. This genetic uniqueness was a key reason for their classification as new species.

Named Novel Species

• Considering the distinct genetic and phenotypic characteristics along with their specific isolation sources, the researchers proposed naming the species isolated from the horse nasopharynx as Acholeplasma equirhinis sp. nov. and the one isolated from the raccoon oral cavity as Mycoplasma procyoni sp. nov.
• These names represent not only the animals they were found in, but also their clear distinction from previously described species in the Mycoplasma and Acholeplasma genera.