Haemoplasma Prevalence and Diversity in Three Invasive Rattus Species from Gauteng Province, South Africa

Detection, genetic diversity, and factors associated with infection by hemotropic mycoplasmas in rodent and marsupial populations in regions of the states of Rio de Janeiro and Parana, Brazil

Hemotropic mycoplasmas, also known as hemoplasmas, are found in several animal species around the world. New species and genotypes of mycoplasmas have been described recently but much more remains to be discovered, especially in wildlife. The objective of this study was to investigate the presence of hemotropic mycoplasmas and diversity of the 16S rDNA sequence fragment in populations of small nonflying mammals in regions with different phytophysiognomies in the states of Rio de Janeiro and Parana, Brazil, as well as to evaluate environmental and animal factors influencing infection rates. Of the 257 animals sampled, 33.8 % (n = 87) were considered positive by conventional PCR. Of the 230 samples from wild rodents (Cricetidae), 36.5 % (n = 84) amplified hemotropic mycoplasma DNA, followed by synanthropic rodents (Muridae) (12.5 %, n = 2/16), and marsupials (Didelphidae) (9.0 %, n = 1/11). The regions with the highest frequency of positivity were Ponta Grossa (46.5 %, n = 27/58) and Cruz Machado (46.1 %, n = 24/52), followed by Nova Friburgo (30.8 %, n = 33/107), and Lidianopolis (12.5 %, n = 5/40). Oligoryzomys had the highest rate of infection (78.5 %), statistically different from Oxymycterus spp. (40.0 %), Akodon spp. (27.0 %) and Sooretamys (8.3 %). Males had a higher prevalence of Mycoplasma spp., being 3.97 times more likely to be positive for hemoplasma than females. Phylogenetic analysis grouped the sequences from this study into two clades, A and E, together with other hemoplasma sequences previously detected in small wild and synanthropic rodents from Brazil, Hungary, and Japan. Haplotype network reveals exclusive haplotypes for wild and synanthropic rodents. Our study reveals considerable genetic diversity suggesting the circulation of at least two species among sequences from this study and highlights the importance of considering environmental and biological factors in the epidemiology of these infections in wild mammals.

Hemotropic Mycoplasmas (Hemoplasmas) in Free-Ranging Azara's Agoutis (Dasyprocta azarae) from an Urban Area of Southern Brazil

Hemotropic mycoplasmas (hemoplasmas) are opportunistic bacteria that attach to the erythrocyte surface, causing infectious anemia in several mammalian species, including rodents. Studies surveying native Azara's agoutis (Dasyprocta azarae) in Brazil are lacking. Accordingly, the present study aimed to assess hemoplasmas infection in free-ranging agoutis from an urban environmental conservation area in Curitiba, southern Brazil. Overall, 11/35 (31.43%) agoutis were positive to hemoplasmas by quantitative PCR (cycle threshold≤34.4). Sequencing of the 16S ribosomal RNA gene indicated Mycoplasma haemomuris infection, closely related to M. haemomuris subsp. ratti, suggesting hemoplasma transmission from urban rats to agoutis. Because the main route of M. haemomuris transmission has been direct rodent-to-rodent infection, the relatively lower positivity that we detected may be the result of low intraspecies contact due to the smaller social units of agoutis, generally consisting of two to four individuals, and low interspecies contact due to only sporadic agouti-rat interactions in urban settings, compared with other rodent species interactions. Further studies should be conducted to determine whether the hemoplasma infection that we found can cause clinical onset and life-threatening anemia in agoutis.

High diversity, novel genotypes, and vertical transmission of hemotropic Mycoplasma in micromammals

Hemotropic mycoplasmas (hemoplasmas) are emerging zoonotic pathogens. Micromammals have received little attention as hosts for hemoplasmas despite their ubiquitous presence, high population abundances, and close association with humans. A PCR protocol targeting a fragment of the 16 S rRNA gene and direct sequencing in blood samples of 189 adult specimens and 35 fetuses belonging to three species of Eulipotyphla (shrews) and seven species of Rodentia, captured in three ecologically diverse habitats in North-Eastern Spain (Steppe, High Mountain, Mediterranean) yielded and occurrence of 26%, including 36% of 39 shrews and 23% of 150 rodents. Sequencing revealed the presence of 14 nucleotide sequence types (ntST) among the 56 readable sequences. In general, each ntST was associated with a given host species, although in some cases, the same ntST was sequenced in different species (chiefly rodents). Most ntST were closely related to rodent and/or bat hemoplasmas, but one was identical with Mycoplasma haemocanis/haemofelis, and others can be considered novel genotypes. High sequence diversity was detected in rodents, whereas in the white-toothed shrew (Crocidura russula), 9/11 sequences from two distant areas were identical. Phylogenetic and network analyses classified our sequences in different clades including hemoplasmas of rodents, carnivores, bats, and humans. Twelve of the fetuses (34.2%) of 9/12 litters (75.0%) of shrews and rodents were hemoplasma-positive, indicating frequent vertical transmission. Our study contributes to expanding our knowledge about the distribution, diversity, and transmission of hemoplasmas.