Morphological and molecular characterization of a marine fish trypanosome from South Africa, including its development in a leech vector

Particle and Fibre Toxicology

Angela J Davies³  Wendy C Gibson²  Nico J Smit³  Scott P Lawton¹  Polly M Hayes¹ 

[1] Molecular Parasitology Laboratory, School of Life Sciences, Kingston University, Kingston upon Thames, Surrey KT1 2EE, UK;School of Biological Sciences, University of Bristol, Bristol BS8 1UG, UK;Water Research Group (Ecology), Unit for Environmental Sciences and Management, North-West University, Potchefstroom Campus, Potchefstroom 2520, South Africa

关键词: 18S rDNA sequences;    Life cycle;    Trypanosoma nudigobii;    Trypanosomes;    Leeches;    Fishes;   

Others  :  814263
DOI  :  10.1186/1756-3305-7-50

 received in 2013-09-19, accepted in 2013-12-11,  发布年份 2014

【 摘 要 】

Background

Trypanosomes are ubiquitous blood parasites of marine and freshwater fishes, typically transmitted by aquatic leeches. Phylogenetic studies have been dominated by examples derived from freshwater fishes, with few marine representatives. Furthermore, life cycle studies on marine fish trypanosomes have focused on those of the northern hemisphere. In this investigation, we have examined the life cycle and molecular taxonomy of a marine fish trypanosome from South Africa.

Methods

To locate trypanosome stages, leeches were removed from fishes captured on the west and south coasts of South Africa, and fish blood films and leech squashes were Giemsa-stained and screened; leeches were also examined histologically. To determine whether trypanosome stages in fishes and leeches were of the same genotype, DNA was extracted from Giemsa-stained fish blood films and leech squashes, and from fish whole blood. Fragments of the 18S rRNA gene were amplified by PCR using trypanosome-specific primers and sequenced. Resulting sequence data were compared with each other and with published trypanosome 18S rDNA sequences, and used for phylogenetic analysis.

Results

Trypanosomes were detected in blood films from fishes of the families Clinidae, Blenniidae and Gobiidae. The flagellates ranged in size and staining properties within the films and across fish hosts. In squashes and histological sections of adult and juvenile leeches, identified as Zeylanicobdella arugamensis, trypanosome developmental stages were predominantly slender epimastigotes. Sequence data showed that trypanosomes derived from fishes were identical, irrespective of whether they were small or large forms; sequences derived largely from leech epimastigotes were also identical to those obtained from fish trypanosomes. Fish and leech trypanosome sequences fell into a marine fish aquatic clade, and aligned most closely with two trypanosome sequences from marine fishes off Norway.

Conclusions

Combined morphological and molecular methods indicate that the trypanosomes examined here represent a single pleomorphic species, rather than the three species described originally. This species is identified as Trypanosoma nudigobii Fantham, 1919 with the leech Z. arugamensis as its vector, and T. capigobii Fantham, 1919 and T. blenniclini Fantham, 1930 are regarded as junior synonyms of the species. Phylogenetic analysis establishes its affinity with marine fish trypanosomes off Norway.

【 授权许可】

   
2014 Hayes et al.; licensee BioMed Central Ltd.

【 图 表 】

Figure 1.

Figure 2.

【 参考文献 】

• [1]Woo PTK: Diplomonadida (Phylum Parabasalia) and Kinetoplastea (Phylum Euglenozoa). In Fish Diseases and Disorders. Volume 1. Protozoan and Metozoan Infections. 2nd edition. Edited by Woo PKT. Oxfordshire: CABI; 2006:46-115.
• [2]Brumpt E: Contribution á l’étude d’évolution des hémogrégarines et des trypanosomes. C R Soc Biol 1904, 57:165-167.
• [3]Brumpt E: Mode de transmission et evolution des trypanosomes des poisons. Descriptions de quelques espésces de trypanoplasmes des poisons d’eau douce. Trypanosome d’un crapaud Africain. C R Soc Biol 1906, 60:162-164.
• [4]Neumann RO: Studien über protozoische Parasiten im Blute von Meeresfischen. Z Hyg Infektionskr 1909, 64:1-112.
• [5]Khan RA: The life cycle of Trypanosoma murmanensis Nikitin. Can J Zool 1976, 54:1840-1849.
• [6]Khan RA: A redescription of Trypanosoma cotti Brumpt and Lebailly, 1904 and its development in the leech, Calliobdella punctata. Ann Parasitol 1978, 53:461-466.
• [7]Khan RA: Longevity of Trypanosoma murmanensis in the leech, Johanssonia sp. Can J Zool 1978, 56:2061-2063.
• [8]Karlsbaak E: A trypanosome of Atlantic cod, Gadus morhua L., transmitted by the marine leech Calliobdella nodulifera (Malm, 1863) (Piscicolidae). Parasitol Res 2004, 93:155-158.
• [9]Karlsbaak E, Haugen E, Nylund A: Morphology and aspects of growth of a trypanosome transmitted by the marine leech Johanssonia arctica (Piscicolidae) from Northern Norway. Folia Parasitol 2005, 52:209-215.
• [10]Fantham HB: Some parasitic protozoa found in South Africa - II. S Afr J Sci 1919, 16:185-191.
• [11]Fantham HB: Some parasitic protozoa found in South Africa - XIII. S Afr J Sci 1930, 27:376-390.
• [12]Paperna I: Parasites, Infections and Diseases of Fish in Africa. An update. Rome: Food and Agriculture Organization of the United Nations; 1996. CIFAT Technical Paper
• [13]Smit NJ, Eiras JC, Ranzani-Paiva MJT, Davies AJ: A Desseria sp. from flathead mullet in South Africa. J Mar Biol Ass UK 2002, 82:675-676.
• [14]Yeld EM, Smit NJ: A new species of Trypanosoma (Kinetoplastida: Trypanosomatidae) infecting catsharks from South Africa. J Mar Biol Ass UK 2006, 86:829-833.
• [15]Hayes PM, Smit NJ, Seddon AM, Wertheim DF, Davies AJ: A new fish haemogregarine from South Africa and its suspected dual transmission with trypanosomes by a marine leech. Folia Parasitol 2006, 53:241-248.
• [16]Gibson WC, Lom J, Peckova H, Ferris VR, Hamilton PB: Phylogenetic analysis of freshwater fish trypanosomes from Europe using ss rRNA gene sequences and random amplification of polymorphic DNA. Parasitology 2005, 130:405-412.
• [17]Davies AJ, Gibson WC, Ferris V, Basson L, Smit NJ: Two genotypic groups of morphologically similar fish trypanosomes from the Okavango Delta, Botswana. Dis Aquat Org 2005, 66:215-220.
• [18]Karlsbakk E, Nylund A: Trypanosomes infecting cod Gadus morhua L. in the North Atlantic: a resurrection of Trypanosoma pleuronectidium Robertson, 1906 and delimitation of T. murmanense Nikitin, 1927 (emend.), with a review of other trypanosomes from North Atlantic and Mediterranean teleosts. Syst Parasitol 2006, 65:175-203.
• [19]Figueroa F, Mayer WE, Lom J, Dyková I, Weller M, Pecková H, Klein J: Fish trypanosomes: their position in kinetoplastid phylogeny and variability as determined from 12 s rRNA kinetoplast sequences. J Eukaryot Microbiol 1999, 46:473-481.
• [20]Gu Z, Wang J, Ke X, Liu Y, Liu X, Gong X, Li A: Phylogenetic position of the freshwater fish trypanosome, Trypanosma ophiocephali (Kinetoplastida) inferred from the complete small subunit ribosomal RNA gene sequence. Parasitol Res 2010, 106:1039-1042.
• [21]Chanseau M, Bosc S, Galiay E, Oules G: L’utilisation de l’huile de clou de girofle comme anesthésique pour les smolts de saumon Atlantique (Salmo salar L.) et comparaison de ses effets avec ceux du 2-phénoxyethanol. Bull Fr Peche Piscic 2002, 365/366:579-589.
• [22]Smit NJ, Van As JG, Basson L: A redescription of the adult male and larvae of Gnathia africana Barnard, 1914 (Gnathiidae: Crustacea: Isopoda) from southern Africa. Folia Parasitol 1999, 46:229-240.
• [23]Hamilton PB: Investigations in Trypanosome Diversity and Evolution Using Molecular Phylogenetic Analysis. Bristol: University of Bristol, School of Biological Sciences; 2003. [PhD thesis]
• [24]Hall TA: BioEdit: a user-friendly biological sequence alignment editor and analysis program for Windows 95/98/NT. Nucl Acids Symp Ser 1999, 41:95-98.
• [25]Tamura K, Peterson D, Peterson N, Steche G, Nei M, Kumar S: MEGA5: molecular evolutionary genetics analysis using maximum likelihood, evolutionary distance, and maximum parsimony methods. Mol Biol Evol 2011, 28:2731-2739.
• [26]Hayes PM, Wertheim DF, Smit NJ, Seddon AM, Davies AJ: Three-dimensional visualization of developmental stages of an apicomplexan fish blood parasite in its invertebrate host. Parasit Vectors 2011, 4:219. BioMed Central Full Text
• [27]Becker CD, Overstreet RM: Haematozoa of marine fishes from the northern Gulf of Mexico. J Fish Dis 1979, 2:469-479.
• [28]Maslov DA, Lukeš J, Jirku M, Simpson L: Phylogeny of trypanosomes as inferred from the small and large subunit rRNAs: implications for the evolution of parasitism in the trypanosomatid protozoa. Mol Biochem Parasitol 1996, 75:197-205.
• [29]Smit NJ, Davies AJ: New host records for Haemogregarina bigemina from the coast of Southern Africa. J Mar Biol Ass UK 1999, 79:933-935.
• [30]Smit NJ, Davies AJ: An encapsulated haemogregarine from the evileye pufferfish in South Africa. J Mar Biol Ass UK 2001, 81:751-754.
• [31]Davies AJ, Smit NJ: The life cycle of Haemogregarina bigemina (Adeleina: Haemogregarinidae) in South African hosts. Folia Parasitol 2001, 48:169-177.
• [32]Davies AJ, Reed CC, Smit NJ: An unusual intraerythrocytic parasite of Parablennius cornutus from South Africa. J Parasitol 2003, 89:913-917.
• [33]Smit NJ, Van As JG, Davies AJ: Taxonomic re-evaluation of the South African fish haemogregarine Desseria fragilis. J Parasitol 2003, 89:151-153.
• [34]Burreson EM, Karlsbakk E: Multiplication of Trypanosoma pacifica (Euglenozoa: Kinetoplastea) in English sole, Parophrys vetulus, from Oregon coastal waters. J Parasitol 2007, 93:932-933.
• [35]Robertson M: Studies on a trypanosome found in the alimentary canal of Pontobdella muricata. Proc R Phys Soc Edinburgh 1907, 17:83-108.
• [36]Robertson M: Further notes on a trypanosome found in the alimentary tract of Pontobdella muricata. Q J Microsc Sci 1909, 54:119-139.
• [37]De Silva PHDH: Zeylanicobdella arugamensis gen. nov. and sp. nov. from Arugam Kalapu, Eastern Province, Ceylon. Spolia Zeylan 1963, 30:46-53.