To the authors’ knowledge, this is the first molecular study documenting the occurrence of hemotropic mycoplasma infections in cats from Romania, expanding the current knowledge of feline hemoplasmas at mainland Europe.
Comparing to several other European countries, the hemoplasma prevalence (21.6%) was higher than that reported in Spain (12.0%, ; 10.6%, ), Italy (18.9% ; 13.2%, ), Germany (15.6%, ), Denmark (16.4%, ) and Serbia (17.2%, ), similar to that described in Greece (20.6%, ), but lower than that reported in Portugal (27.1%, ; 43.4%, ) or northern Italy (33.1%; ). It is important to mention that comparing the results of different studies should be interpreted with caution, because differences in study design (e.g. sample size, sampling strategy), epidemiological parameters of the sampled population (e.g. health status of cats, cat's living environment) and the molecular diagnostic techniques used (e.g. conventional PCR, real-time PCR or a combination of both) in processing the blood samples in different studies could be considered sources of variation for the recorded hemoplasma prevalence. In this regard, it is important to highlight that in our study there was a bias towards the elevation of the infection prevalence, because all the investigated animals were clinically ill at presentation and sampling with suggestive signs for hemoplasma infections.
In accordance with our results, the dominance of CMhm in the screened feline population has been previously confirmed in other molecular surveys [7, 11–22], but others have reported Mhf as the predominant species . It has been hypothesized previously , that CMHm has a more efficient replication and infection capacity, but is associated with a lower pathogenic potential compared to other two species of hemoplasma and often result in asymptomatic carriage status in cats. This supports its dominant occurrence in this study and the other reports. Currently, without hematological examination, the evaluation of the pathogenicity of the recorded mycoplasma species in Romanian cats remains an open question for future investigation.
The carriage of multiple hemoplasma species, as well as the presence of CMt was not detected. Results of other studies have shown that co-infections with different combination of hemoplasmas frequently occur [14, 17, 19], and CMt seems to be the least frequently encountered feline hemotropic mycoplasma species, its prevalence ranging from 0.5 to 6.2% [7, 11, 12, 14, 19]. In other investigations [10, 18, 22], that process a limited number of samples as in the case of our study, the lack of the CMt detection was reported. Therefore, further studies, processing a significantly larger number of samples, are still necessary in order to obtain a more accurate overview and to conclude whether CMt is implicated in Romanian cats’ mycoplasma infections.
Outdoor access lifestyle was the only epidemiological measure that was associated with hemoplasma infection in this study. Other studies have described several factors significantly associated with the presence of hemotropic mycoplasmas in cats including adult  or older [7, 18, 20–22, 24] age, male gender [7, 14, 17, 19–21, 24], non-pedigree breed , collection of blood during warm months [14, 15], and FeLV/FIV positivity status [11–15, 17, 19–21, 24, ]. Similar to our finding, the increased likelihood of cats being infected with hemotropic mycoplasmas with outdoor access has been frequently reported in other studies [7, 11, 14, 19]. This observation can be sustained by the fact that this lifestyle increases, diversifies and perpetuates the relationships between cats, resulting in the possible transmission of mycoplasma from positive to negative animals, via direct (e.g. fighting or biting) or vector borne (fleas or ticks) transmission, as have been previously suggested [4–8, 11, 17, 24]. However, the scientific demonstration of this hypothesis remains, until now, unfulfilled.