| Literature DB >> 27198803 |
Amanda D Barbosa1, John T Mackie2, Robyn Stenner3, Amber Gillett3, Peter Irwin4, Una Ryan4.
Abstract
Little is known about the genetic diversity and pathogenicity of trypanosomes in Australian bats. Recently a novel trypanosome species was identified in an adult female little red flying fox (Pteropus scapulatus) with clinical and pathological evidence of trypanosomosis. The present study used morphology and molecular methods to demonstrate that this trypanosome is a distinct species and we propose the name Trypanosoma teixeirae sp. n. Morphological comparison showed that its circulating trypomastigotes were significantly different from those of Trypanosoma pteropi and Trypanosoma hipposideri, two species previously described from Australian bats. Genetic information was not available for T. pteropi and T. hipposideri but phylogenetic analyses at the 18S ribosomal RNA (rRNA) and glycosomal glyceraldehyde phosphate dehydrogenase (gGAPDH) loci indicated that T. teixeirae sp. n. was genetically distinct and clustered with other bat-derived trypanosome species within the Trypanosoma cruzi clade.Entities:
Keywords: 18S ribosomal RNA (rRNA); Glycosomal glyceraldehyde phosphate dehydrogenase (gGAPDH); Little red flying fox (Pteropus scapulatus); Morphology; PCR; Phylogeny; Trypanosoma teixeirae sp. n
Mesh:
Substances:
Year: 2016 PMID: 27198803 PMCID: PMC7116988 DOI: 10.1016/j.vetpar.2016.05.002
Source DB: PubMed Journal: Vet Parasitol ISSN: 0304-4017 Impact factor: 2.738
Genbank accession numbers and sources (where known) of trypanosome isolates included in the phylogenetic analyses.
| Trypanosome species | Host origin | Geographic origin | GenBank accession numbers | |
|---|---|---|---|---|
| 18S rDNA | gGAPDH | |||
| Bat ( | Australia | KT907061 | KT907062 | |
| Bat | Brazil | FJ900242 | GQ140364 | |
| Tamarin | Japan | AJ012413 | AB362561 | |
| Bat | Brazil | FJ001666 | GQ140362 | |
| Bat | Mozambique | JN040987 | JN040964 | |
| Bat | England | AJ009166 | AJ620283 | |
| Bat | Gabon | AJ012418 | GQ140365 | |
| Bat | Mozambique | KF192979 | KF192958 | |
| Bat | Mozambique | – | KF192969 | |
| Bat | Brazil | FJ900241 | GQ140358 | |
| Bat | Brazil | FJ001664 | GQ140360 | |
| Human | Brazil | AF301912 | GQ140353 | |
| Rat (Rattus rattus) | Brazil | AJ012411 | AJ620267 | |
| Palm civet | Cameroon | FM202492 | FM164793 | |
| Monkey | Cameroon | FM202493 | FM164794 | |
| Kangaroo | Australia | AJ009168 | AJ620276 | |
| Possum | Australia | JN315383 | AJ620276 | |
| Woylie | Australia | KC753537 | KC812988 | |
| Eagle | Slovakia | AF416559 | – | |
| Currawong | Australia | AJ620557 | AJ620264 | |
| American kestrel | Germany | AJ223562 | FJ649486 | |
| Koala | Australia | FJ649479 | FJ649485 | |
| Rat (Rattus rattus) | England | AJ009156 | AJ620272 | |
| Vole | England | AJ009158 | AJ620273 | |
| Cattle | EU477537 | AF053744 | ||
| – | X59955 | |||
| Human | Uganda | AJ009142 | – | |
| Human | Nigeria | AJ009141 | – | |
| Capybara | Brazil | AJ009154 | AF053743 | |
| Koala | Australia | GU966588 | – | |
| Koala | Australia | – | GU966585 | |
| Woylie | Australia | KC753530 | KC812982 | |
| Woylie | Australia | KC753531 | KC812983 | |
| Koala | Australia | GU966589 | GU966587 | |
| Woylie | Australia | KC753533 | KC812984 | |
| Woylie | Australia | KC753532 | KC812985 | |
| Woylie | Australia | KC753534 | KC812986 | |
| Woylie | Australia | KC753535 | – | |
| Woylie | Australia | KC753536 | KC812987 | |
| African toad | Africa | AJ009157 | AJ620253 | |
| Bullfrog | Canada | AJ009161 | AJ620256 | |
| Platypus | Australia | AJ132351 | AJ620266 | |
| Eel | Portugal | AJ620552 | – | |
| Catfish | Africa | AJ620555 | AJ620251 | |
Fig. 1Light photomicrographs of diff quick stained blood film showing Trypanosoma teixeirae sp. n. trypomastigotes in the blood of a red flying fox (Pteropus scapulatus) (a–c) and (d) Round epimastigote form. Scale bars represent 10 μm.
Mean dimensions and standard errors (S.E.) of morphological features of Trypanosoma teixeirae sp.n. isolated from a little red flying fox’s blood.
| Featurea | No. of organisms measured | Observed range (μm) | Mean ± S.E. (μm) |
|---|---|---|---|
| Total length | 8 | 20.4–30.8 | 25.9 ± 1.2 |
| Width | 8 | 1.3–2.3 | 1.9 ± 0.1 |
| PK | 7 | 1.5–2.4 | 2 ± 0.15 |
| KN | 9 | 3.3–6.2 | 4.9 ± 0.3 |
| NA | 9 | 5.1–9.8 | 7.8 ± 0.5 |
| FF | 8 | 10.0–12.9 | 11.3 ± 0.4 |
aTotal length: total body length measured along mid-line including free-flagellum.
Width: maximum width measured at nucleus level (undulating membrane included).
PK: distance between the posterior end and the kinetoplast.
KN: distance between the kinetoplast and posterior edge of the nucleus.
NA: distance between the anterior edge of the nucleus and the anterior end of the body.
FF: length of the free flagellum.
Comparison between morphological dimensions of blood trypomastigotes of Trypanosoma teixeirae sp. n. with Trypanosoma pteropi and Trypanosoma hipposideri.
| Morphological Feature (μm) | ||||||
|---|---|---|---|---|---|---|
| Total length | Width | PK | KN | NA | FF | |
| 20.4–30.8 25.9 | 1.3–2.3 | 1.5–2.4 | 3.3–6.2 | 5.1–9.8 | 10.0–12.9 | |
| 1.9 | 2.0 | 4.9 | 7.8 | 11.3 | ||
| 18.0–22.0 | 2.0–4.0 | 1.5–4.0 | 4.0–5.0 | 8.0–10.0 | 8.0–12.0 | |
| 20.0* | 3.0* | 2.75* | 4.5 | 9.0 | 10.0 | |
| 10.5–13.0 | 1.5–2.0 | 1.0–2.5 | 4.0–6.0 | 1.5–5.0 | 4.0–8.0 | |
| 11.65* | 1.75 | 1.75 | 5.0 | 3.25* | 6.0* | |
Total length: total body length measured along mid-line including free-flagellum; Width: maximum width measured at nucleus level (undulating membrane included); PK: distance between the posterior end and the kinetoplast; KN: distance between the kinetoplast and posterior edge of the nucleus; NA: distance between the anterior edge of the nucleus and the anterior end of the body; FF: length of the free flagellum. Ranges given with mean for Trypanosoma teixeirae sp. n. As the mean dimensions were not available for Trypanosoma pteropi or Trypanosoma hipposideri the median value of the range is presented in the table and was used for statistical analysis. For each column, values followed by an asterisk are significantly different to the T. teixeirae sp.n. value (p < 0.01).
Fig. 2Phylogenetic relationships of Trypanosoma teixeirae sp. n. with other trypanosomes, based on 18S rDNA partial sequences (∼730 bp). Evolutionary relationships were determined by Maximum Likelihood, based on the Tamura-Nei model (Tamura et al., 2013). Bootstrap values (>60%) based on 500 replicates are indicated at the left of each supported node. The scale bar is the proportion of base substitutions per site. Trypanosome species from bats are shown with an asterisk.
Fig. 3Phylogenetic relationships of Trypanosoma teixeirae sp. n. with other trypanosomes, based on gGAPDH partial sequences (∼775 bp). Evolutionary relationships were determined by Maximum Likelihood, based on the Tamura-Nei model (Tamura et al., 2013). Bootstrap values (>60%) based on 500 replicates are indicated at the left of each supported node. The scale bar is the proportion of base substitutions per site. Trypanosome species from bats are shown with an asterisk.
Genetic distances between Trypanosoma teixeirae sp. n. and other trypanosome species at 18S rRNA and gGAPDH loci.
| Trypanosome species/isolate | Genetic distances (%) | |
|---|---|---|
| 18S rDNA | gGAPDH | |
| 1% | 14% | |
| 1% | 15% | |
| 1% | 16% | |
| 1% | 16% | |
| 1% | 17% | |
| 1% | 17% | |
| 1% | 17% | |
| 2% | 17% | |
| 1% | 18% | |
Genetic distances were calculated in MEGA 6 (Tamura et al., 2013) using the Tamura-Nei model (Tamura and Nei 1993).