Preliminary detection of haemoplasma in Thai cat blood samples using universal primers: identifying 'Candidatus Mycoplasma haemominutum' and closely related species.

Abstract

ObjectivesThis study examined feline haemoplasmas (Mycoplasma haemofelis, 'Candidatus Mycoplasma haemominutum' [CMhm] and 'Candidatus Mycoplasma turicensis') infecting Thai domestic cats, using the 16S and 23S rRNA genes as genetic markers.MethodsBlood samples from 20 cats were obtained from a diagnostic laboratory and nucleic acids were extracted from each sample using a commercial kit. PCR targeting the 16S rRNA gene was used to screen haemoplasmas in the samples. Positive PCR samples were further sequenced using the 16S and 23S rRNA genes. The sequences from each genetic marker were analysed using Nucleotide BLAST, phylogeny and genetic network analyses.ResultsAmong the 20 samples, five were infected with haemoplasmas. In the 16S rRNA gene sequencing, four sequences were assigned to CMhm and the remaining sequence was likely to be a closely related species of CMhm. In the 23S rRNA gene sequencing, four sequences from the same samples used for 16S rRNA gene sequencing were identified as CMhm and one sequence could be a putative novel haemoplasma species closely related to CMhm.Conclusions and relevanceOnly CMhm and its closely related species were identified in this study. Although CMhm has been recognised as a low-virulence parasite, cases of severe anaemia in cats infected with CMhm have been found. Thus, such cases could be confirmed via the analysis of 16S and 23S rRNA genes. Furthermore, molecular detection and genetic analyses of feline haemoplasmas in additional cat blood samples should be conducted using PCR assay and DNA sequencing based on universal primers of 16S rRNA and 23S rRNA genes to enable more specific identification.