The aim of this study was to determine the prevalence and risk factors for Mycoplasma haemofelis (Mhf) and 'Candidatus Mycoplasma haemominutum' (Mhm) infections in domestic cats tested for feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) with a commercial enzyme-linked immunosorbent assay (ELISA) kit. Based on serological testing, cats were grouped as i) FIV-positive (n=25); ii) FeLV-positive (n=39); iii) FIV/FeLV-positive (n=8); and iv) FIV/FeLV-negative (n=77). Complete blood counts were followed by DNA extraction, species-specific polymerase chain reaction (16S rRNA gene) for Mhf and Mhm and Southern blotting for all animals. Mhf DNA was found in 4.0, 2.6, 12.5 and 7.8% of the cats from groups i, ii, iii and iv, respectively, while 32, 5.1, 50 and 5.2% of these animals had an Mhm infection. Cats with FIV (OR=4.25, P=0.009) and both FIV and FeLV (OR=7.56, P=0.014) were at greater risk of being hemoplasma infected than retroviral-negative cats, mainly due to Mhm infection (OR=8.59, P=0.001 and OR=18.25, P=0.001, respectively). Among pure-breed cats, FIV-positive status was associated with hemoplasma infection (OR 45.0, P=0.001).

Recent studies have been conducted in Brazil using molecular techniques for the detection of hemotrophic mycoplasmas in several mammals. In domestic cats, Mycoplasma haemofelis, 'Candidatus M. haemominutum', and 'Candidatus M. turicensis' infections have been identified. These species have also been found in free-ranging and captive neotropical felid species. Two canine hemoplasmas, Mycoplasma haemocanis and 'Candidatus Mycoplasma haematoparvum', have been identified in dogs. In commercial swine populations, Mycoplasma suis was found to be highly prevalent, especially in sows. Moreover, novel mycoplasma species have been identified in Brazilian commercial pigs and domestic dogs. A hemoplasma infection in a human patient infected with the human immunodeficiency virus (HIV) was also recently documented. In conclusion, hemoplasma species are common and important infectious agents in Brazil. Further studies should be conducted to better understand their impact on pets, production animals, and wildlife fauna, as well as their role as zoonotic agents, particularly in immunocompromised patients.Keywords: Hemoplasma, Mycoplasma haemofelis, Mycoplasma suis, HIV. ResumoEstudos recentes utilizando técnicas moleculares para a detecção de micoplasmas hemotróficos em diferentes mamíferos têm sido conduzidos no Brasil. Em gatos domésticos, infecções por Mycoplasma haemofelis, 'Candidatus M. haemominutum' e 'Candidatus M. turicensis' foram identificadas. Estas espécies também foram encontradas em felídeos neotropicais de vida livre e de cativeiro. Dois hemoplasmas caninos, Mycoplasma haemocanis e 'Candidatus Mycoplasma haematoparvum', foram identificados em cães domésticos. Em populações comerciais de suínos, Mycoplasma suis possui alta prevalência, especialmente em porcas. Além disso, novas espécies de hemoplasmas foram detectadas em suínos comercias e cães. Infecção por um hemoplasma em um paciente humano infectado com o vírus da imunodeficiência humana (HIV) foi recentemente documentada. Em conclusão, espécies de hemoplasmas são comuns e importantes agentes de infecções no Brasil. Estudos futuros devem ser conduzidos para melhor entender seu impacto em cães e gatos, animais de produção e na fauna silvestre, e também para determinar o seu papel como agentes zoonóticos, particularmente em pacientes imunocomprometidos.Palavras-chave: Hemoplasma, Mycoplasma haemofelis, Mycoplasma suis, HIV.

Although the prevalence of E canis infection was higher in thrombocytopenic dogs, less than one third of these dogs had demonstrable E canis infection. Thus, thrombocytopenia is not specific for the detection of E canis infection and should not be used solely to establish a diagnosis of canine ehrlichiosis, even in a geographic area with relatively high disease prevalence.