Occurrence and identification of hemotropic mycoplasmas (Hemoplasmas) in free ranging and laboratory rats (Rattus norvegicus) from two Brazilian zoos

Abstract

BackgroundHemotropic mycoplasmas (hemoplasmas), bacteria belonging to the class Mollicutes, are obligatory red blood cell pathogens of a variety of animal species. They may cause acute anemia that is life-threatening or chronic disease that is clinically silent, but may interfere with results of experimental studies when using infected animals. Since these bacteria cannot be cultivated, molecular techniques are the gold standard for diagnosing an infection, investigating its prevalence, and describing new species. Mycoplasma coccoides and M. haemomuris are the most commonly recognized hemoplasmas in the blood of wild and laboratory rodents. Neither the epidemiology nor clinical and molecular characterization of hemoplasma infection in free-ranging rodents in Brazil has been previously reported. The aims of this study were to investigate the occurrence of hemoplasmas in free-ranging rats (Rattus norvegicus) captured in the Passeio Público and Curitiba Zoo and compare hematologic parameters of infected and non-infected animals.ResultsAnti-coagulated blood samples collected from 43 free-ranging and 20 nursery rats were included in the study. Overall 63.5 % were positive using SYBR® Green quantitative PCR (qPCR) of the 16S rRNA gene to screen for hemoplasma infection (72 % among free-ranging rats; 45 % among laboratory-raised rats). Sequencing of the qPCR products showed that all but one sample had >98 % identity to M. haemomuris. Phylogenetic analysis based on a fragment of approximately 1300 bp of the 16S rRNA gene showed 99 % identity to a new hemoplasma from European rats and 98 % identity to a hemotropic mycoplasma described infecting a European harvest mouse (Micromys minutus). No statistically significant changes in hematologic parameters between infected and non-infected rats were found, confirming the low pathogenicity and/or silent characteristics of the infection.ConclusionsOur findings suggest that hemoplasmas are likely endemic in rodent species in this region. The epidemiology, especially as it relates to the mode of transmission, needs to be further investigated as well as the possibility that other animal species, including humans, might become infected.

Occurrence and molecular characterization of hemoplasmas in domestic dogs and wild mammals in a Brazilian wetland

“…A closer contact among rodents from urban areas with different host species and arthropods could explain the differences observed in prevalence rates. In spite of that, a high diversity of Mycoplasma genotypes has been detected in rodents from Japan, Hungary and Brazil (Vieira et al, 2009;Sashida et al, 2013;Conrado et al, 2015;Gonçalves et al, 2015;Hornok et al, 2015). A genotype closely related to M. haemomuris was detected in a wild rodent (O. mamorae) in the present study.…”

“…A genotype closely related to M. haemomuris was detected in a wild rodent (O. mamorae) in the present study. The same genotype has been already detected in wild rodents from the same biome Pantanal (Gonçalves et al, 2015), suggesting that M. haemomuris, besides being the most common hemoplasma species found in synantropic rodents (Conrado et al, 2015;Hornok et al, 2015) seems to be the main hemotrophic mycoplasma species parasitizing wild rodents in the Pantanal biome in Brazil.…”

“…However, the occurrence of Mycoplasma infection found among wild rodents in Pantanal biome in the above mentioned study was significantly lower than that found in the others three Brazilian biomes (Cerrado, Amazon Forest, and Atlantic Forest) (Gonçalves et al, 2015). Additionally, high occurrence of hemoplasmas was found among capybaras (64%), synanthropic and laboratory rodents (Rattus novergicus) (63.5%) from urban areas in the state of Paraná, Brazil (Vieira et al, 2009;Conrado et al, 2015). A closer contact among rodents from urban areas with different host species and arthropods could explain the differences observed in prevalence rates.…”

“…Although hemoplasmas have been detected in domestic cats (Braga et al, 2012;Miceli et al, 2013;André et al, 2014;Santis et al, 2014) and dogs (Ramos et al, 2010;Alves et al, 2014;Valle et al, 2014;Soares et al, 2016) from several localities in Brazil, few reports have documented the occurrence of hemoplasma species in wild animals. For instance, hemoplasmas have been detected in wild carnivores maintained in captivity in zoos (Willi et al, 2007;Guimarães et al, 2007;André et al, 2011), wild rodents (Vieira et al, 2009;Conrado et al, 2015;Gonçalves et al, 2015), monkeys (Bonato et al, 2015), and deer (Grazziotin et al, 2011) in Brazil.…”

Evidence and molecular characterization ofBartonellaspp. and hemoplasmas in neotropical bats in Brazil

“…have been detected in a variety of wild animals all over the world. In Brazil, these agents have been reported in several wild mammals, such as wild carnivores [15][16][17], deer [18], peccary [19], non-human primates [20,21], and rodents [22][23][24][25][26].…”