Molecular characterization and phylogenetic analysis of hemotropic Mycoplasma in cats in fars province, Iran, and its association with blood groups and hematological alterations.

Blood group antigens are considered to be potential determinants influencing host susceptibility to infectious agents, possibly functioning as cellular receptors that may facilitate bacterial, viral, and protozoal attachment—including Mycoplasma species. In feline hemoplasmosis, enzymatic cleavage of N-acetylneuraminic acid may disrupt erythrocyte glycopeptides or glycolipids, thereby exposing cryptic antigenic determinants that trigger immune activation. Understanding these molecular interactions can elucidate the relationship between host phenotype and pathogen behavior. This study aimed to investigate the molecular prevalence and genetic diversity of feline hemoplasmas in southern Iran and to examine their hematological effects and potential associations with blood groups, with emphasis on identifying novel Mycoplasma genotypes. Blood samples were collected from 109 domestic cats presented to the Shiraz Veterinary Teaching Hospital over a two-year period, encompassing both healthy and diseased individuals. PCR amplification targeting the 16S rRNA gene was used for species identification. Molecular analysis revealed hemoplasma positivity in 10 cats (9%). Three cats (2.7%) were infected with Mycoplasma haemofelis, six (5.5%) with Candidatus Mycoplasma haemominutum, and one cat (0.9%) harbored a genetically distinct hemotropic Mycoplasma species. The 16S rRNA sequence (GenBank accession PQ139507) exhibited marked divergence from previously described feline hemoplasmas and showed phylogenetic relatedness—but not identity—to genotypes recently reported in Cambodian dogs (ON620261) and Croatian European badgers (OQ749696), suggesting a putative novel lineage. Among the sampled cats, 14% with blood type A and 7.7% with blood type B were hemoplasma-positive, although this difference was not statistically significant (p = 0.4). Infection prevalence differed significantly by sex (p = 0.04), with males more frequently affected, whereas age, breed, and outdoor access showed no significant association (p > 0.05). Hemoplasma-positive cats exhibited significantly lower red blood cell counts (p = 0.021) and hemoglobin concentrations (p = 0.038) compared with uninfected individuals, indicating a mild to moderate anemic response. Other hematological parameters remained within normal ranges, showing no significant variation. In summary, feline hemoplasma infection appears relatively common among cats in southern Iran and is more prevalent in males. While blood type does not represent a major risk determinant, the observed hematologic alterations and detection of a putative novel Mycoplasma genotype underscore the need for expanded molecular and pathogenic studies across regional feline populations.