‘Candidatus Mycoplasma Haemoalbiventris’ and Tick-Borne Pathogens in Black-Eared Opossum (Didelphis aurita) from Southeastern Brazil

Abstract

The black-eared opossum (Didelphis aurita) is a South American synanthropic marsupial. The presence of opossums in domestic spaces is relevant in the One-Health context since they are hosts of pathogens and ectoparasites that may affect the health of domestic animals and humans. In this study, we aim to determine the occurrence of hemoplasmas and selected tick-borne pathogens in free-ranging black-eared opossums, along with their molecular characterization, hematological and biochemical evaluation and factors associated with infection, in the municipality of Viçosa, State of Minas Gerais, southeastern Brazil. Thirty black-eared opossums were trapped between March 2021 and June 2022. Ectoparasites were collected. Hematological and biochemical analyses were performed. DNA from EDTA-blood samples were analyzed by PCR and qPCR assays. By molecular analyses, ‘Candidatus Mycoplasma haemoalbiventris’ was the most prevalent hemoparasite (73.3%), followed by Hepatozoon sp. (22.2%). Significant differences were observed in the number of platelets, and in the concentration of protein and globulins in the animals infected by ‘Ca. M. haemoalbiventris’ when compared with the negative group. This is the first report of ‘Ca. M. haemoalbiventris’ infection in D. aurita.

Molecular detection of hemoplasmas in rescued black-eared opossums (Didelphis aurita Wied-Neuwied, 1826) from southeastern Brazil, with evidence of a novel genotype infecting marsupials

“…The anemia detected in all positive opossums is probably associated to other causes, such as inflammatory or chronic conditions, as all D. aurita of the present study presented such hematological finding. Platelet and plasma protein values ​​found in hemoplasma positive animals were within the reference value, corroborating with Orozco et al (2022) . The white blood cell count of these animals revealed leukocytosis, a finding closely related to inflammatory conditions or systemic stress mediated by cortisol ( Herrero-Cervera et al, 2022 ).…”

“…was found in 20% of the sampled black-eared opossums. Previous studies have found higher hemoplasma prevalence rates (ranging from 32.5-87.5%) in white-eared opossums from different geographic regions and biomes (Atlantic Forest and Cerrado) of Brazil ( Massini et al, 2019 ; Gonçalves et al, 2020 ; Orozco et al, 2022 ; Pontarolo et al, 2021 ). Differences in environment conditions may influence habits and behavior of the opossums, and threfore, their exposure to hemoplasmas, which may explain the low percentage of positive animals found herein.…”

“…Recently, a high occurrence of ‘ Ca. M. haemoalbiventris’ was found in D. aurita from Minas Gerais State, although infection was also not associated with the presence of ectoparasites ( Orozco et al, 2022 ). Herein, Ctenocephalides felis felis fleas were found parasitizing three animals, although they were not PCR positive for hemotropic Mycoplasma spp.…”

“…Blood count data were expressed through the mean and standard deviation (SD). For comparison of data, reference values were considered as determined by Casagrande et al (2009) and Orozco et al (2022) .…”

“…The mechanisms of natural transmission in animals have not yet been fully elucidated. To date, hemoplasmas known to infect Didelphis are ' Candidatus Mycoplasma haemoalbiventris', described in white-eared opossums ( D. albiventris ) in the south and central-west regions of Brazil ( Massini et al, 2019 ; Gonçalves et al, 2020 ; Pontarolo et al, 2021 ; Oliveira et al, 2021 ) and black-eared opossums ( D. aurita ) in southeastern Brazil ( Orozco et al, 2022 ). Additionally, ‘ Candidatus Mycoplasma haemodidelphis’ have been detected in the Virginia opossum ( D. virginiana ) from USA ( Messick et al, 2002 ).…”