Spironucleus species: Economically-important fish pathogens and enigmatic single-celled eukaryotes

Journal of Aquaculture Research and Development

Volumn , Issue SPEC. ISSUE 2, 2011, Pages

  Williams, Catrin F ^a   Lloyd, David ^a   Poynton, Sarah L ^b   Jorgensen, Anders ^c   Millet, Coralie Om ^a   Cable, Joanne ^a  

^a CARDIFF UNIVERSITY   (United Kingdom)

^b JOHNS HOPKINS UNIVERSITY SCHOOL OF MEDICINE   (United States)

^c NORWEGIAN VETERINARY INSTITUTE   (Norway)

Author keywords

Aquaculture; Diplomonad; Garlic; Hexamita; Hydrogenosomes; Spironucleus; Taxonomy

Indexed keywords

EID: 84879464330     PISSN: None     EISSN: 21559546     Source Type: Journal    
DOI: 10.4172/2155-9546.S2-002     Document Type: Article

References (129)

1. Poynton SL, Sterud E (2002) Guidelines for species description of diplomonad fagellates in fsh. J Fish Dis 25: 15-31.
2. Fenchel T, Bernard C, Esteban G, Finlay BJ, Hansen PJ, et al. (1995) Microbial diversity and activity in a Danish fjord with anoxic deep water. Ophelia 43: 45-100.
3. Brugerolle G (1975) Contribution a l'étude cytologique et phylétique des diplozoaires (Zoomastigophorea, Diplozooa, Dangeard 1910). VI. Caractères généraux des diplozoaires. Protistologica XI: 111-118.
4. Adam RD (2001) Biology of Giardia lamblia. Clin Microbiol Rev 14: 447-475.
5. Poynton SL, Fraser W, Francis-Floyd R, Rutledge P, Reed P, et al. (1995) Spironucleus vortens n. sp. from the fresh-water Angelfsh Pterophyllum scalare: morphology and culture. J Euk Microbiol 42: 731-742.
6. Sterud E, Mo TA, Poppe TT (1998) Systemic spironucleosis in sea-farmed Atlantic salmon Salmo salar, caused by Spironucleus barkhanus transmitted from feral Arctic char Salvelinus alpinus? Dis Aquat Org 33: 63-66.
7. Cooper GL, Charlton BR, Bickford AA, Nordhausen R (2004) Hexamita meleagridis (Spironucleus meleagridis) infection in chukar partridges associated with high mortality and intracellular trophozoites. Avian Dis 48: 706-710.
8. Fain MA, Karjala Z, Perdue KA, Copeland MK, Cheng LI, et al. (2008) Detection of Spironucleus muris in unpreserved mouse tissue and fecal samples by using a PCR assay. J Am Assoc Lab Anim Sci 47: 39-43.
9. Slavin D, Wilson JE (1953) Hexamita meleagridis. Nature 172: 1179-1181.
10. Matthiesen T, Kunstyr I, Tuch K (1976) Hexamita muris infection in mice and feld hamsters in an experimental laboratory colony. Z Versuchstierkd 18: 113-120.
11. Kunstyr I (1977) Infectious form of Spironucleus (Hexamita) muris: banded cysts. Lab Anim 11: 185-188.
12. Kunstyr I, Ammerpohl E (1978) Resistance of faecal cysts of Spironucleus muris to some physical factors and chemical substances. Lab Anim 12: 95-97.
13. Brugerolle G, Kunstyr I, Senaud J, Friedhoff KT (1980) Fine structure of trophozoites and cysts of the pathogenic diplomonad Spironucleus muris. Z Parasitenkd 62: 47-61.
14. Brett SJ, Cox FE (1982) Interactions between the intestinal fagellates Giardia muris and Spironucleus muris and the blood parasites Babesia microti, Plasmodium yoelii and Plasmodium berghei in mice. Parasitology 85: 101-110.
15. Januschka MM, Erlandsen SL, Bemrick WJ, Schupp DG, Feely DE (1988) A comparison of Giardia microti and Spironucleus muris cysts in the vole: an immunocytochemical, light, and electron microscopic study. J Parasitol 74: 452-458.
16. Harper FD (1991) Hexamita species present in some avian species in South Wales. Vet Rec 128: 130.
17. Kunstyr I, Poppinga G, Friedhoff KT (1993) Host specifcity of cloned Spironucleus sp. originating from the European hamster. Lab Anim 27: 77-80.
18. Pennycott TW (1998) Carriage of Trichomonads, Hexamita species and Blastocystis species by adult pheasants. Vet Rec 143: 142-143.
19. Lloyd S, Irvine KL, Eves SM, Gibson JS (2005) Fluid absorption in the small intestine of healthy game birds and those infected with Spironucleus spp. Avian Pathol 34: 252-257.
20. Nigrelli RF, Hafter E (1947) A species of Hexamita from the skin of two cichlids. Anat Rec 99: 683.
21. O'Brien GM, Ostland VE, Ferguson H (1993) Spironucleus-associated necrotic enteritis in angelfsh (Pterophyllum scalare). Can Vet J 34: 301-303.
22. Sterud E (1998) In vitro cultivation and temperature-dependent growth of two strains of Spironucleus barkhanus (Diplomonadida: Hexamitidae) from Atlantic salmon Salmo salar and grayling Thymallus thymallus. Dis Aquat Org 33: 57-61.
23. Tojo JL, Santamarina MT (1998) Oral pharmacological treatments for parasitic diseases of rainbow trout Oncorhynchus mykiss. I: Hexamita salmonis. Dis Aquat Org 33: 51-56.
24. Paull GC, Matthews RA (2001) Spironucleus vortens, a possible cause of hole-in-the-head disease in cichlids. Dis Aquat Org 45: 197-202.
25. Guo FC, Woo PT (2004) Detection and quantifcation of Spironucleus barkhanus in experimentally infected Atlantic salmon Salmo salar. Dis Aquat Org 61: 175-178.
26. Guo FC, Woo PT (2004) Experimental infections of Atlantic salmon Salmo salar with Spironucleus barkhanus. Dis Aquat Org 61: 59-66.
27. Jorgensen A, Sterud D (2006) The marine pathogenic genotype of Spironucleus barkhanus from farmed salmonids redescribed as Spironucleus salmonicida n. sp. J Eukaryot Microbiol 53: 531-541.
28. Poynton SL, Morrison CM (1990) Morphology of diplomonad fagellates: Spironucleus torosa n. sp. from Atlantic cod Gadus morhua L., and haddock Melanogrammus aeglefnus (L.) and Hexamita salmonis Moore from brook trout Salvelinus fontinalis (Mitchill). J Protozool 37: 369-383.
29. Sterud E (1998) Electron microscopical identifcation of the fagellate Spironucleus torosa (Hexamitidae) from burbot Lota lota (Gadidae) with comments upon its probable introduction to this freshwater host. J Parasitol 84: 947-953.
30. Sterud E, Poppe T, Borno G (2003) Intracellular infection with Spironucleus barkhanus (Diplomonadida: Hexamitidae) in farmed Arctic char Salvelinus alpinus. Dis Aquat Org 56: 155-161.
31. Jorgensen A, Sterud E (2004) SSU rRNA gene sequence reveals two genotypes of Spironucleus barkhanus (Diplomonadida) from farmed and wild Arctic charr Salvelinus alpinus. Dis Aquat Org 62: 93-96.
32. Scheltema RS (1962) The relationship between the fagellate protozoon Hexamita and the oyster Crassostrea virginica. J Parasitol 48: 137-141.
33. Uzmann JR, Hayduk SH (1963) In vitro culture of the fagellate protozoan Hexamita salmonis. Science 140: 290-292.
34. Khouw BT, McCurdy HD Jr (1968) Nutritional studies of a fagellated protozoan Hexamita infata from the Canadian oyster, Crassostrea virginica. Can J Microbiol 14: 817-821.
35. Mo TA, Poppe T, Iversen L (1990) Systemic hexamitosis in salt-water reared Atlantic salmon. Bull Eur Assoc Fish Pathol 10: 69.
36. Poppe T, Mo TA, Iversen L (1992) Disseminated hexamitosis in sea-caged Atlantic salmon. Dis Aquat Org 14: 91-97.
37. Poppe T, Mo TA (1993) Systemic, granulomatous hexamitosis of farmed Atlantic salmon: interactions with wild fsh. Fish Res 17: 147-152.
38. Kent ML, Ellis J, Fournie JW, Dawe SC, Bagshawe JW et al. (1992) Systemic hexamitid infection in seawater pen-reared chinook salmon. Dis Aquat Org 14: 81-89.
39. Woo PTK, Poynton SL (1995) Diplomonadida, Kinetoplastida and Amoebida (Phylum Sarcomastigophora). In: Woo PTK (ed.), Fish Diseases and Disorders, Vol. 1, Protozoan and Metozoan Infections, CAB International, Wallingford, UK, pp. 27-96.
40. Ferguson HW, Moccia RD (1980) Disseminated hexamitosis in Siamese fghting fish. J Am Vet Med Assoc 177: 854-857.
41. Goldstein R (1979) Disease prevention and control. Freshwat Mar Aquar, June: 52-53.
42. Dawson SC, Pham JK, House SA, Slawson EE, Cronembold D, et al. (2008) Stable transformation of an episomal protein-tagging shuttle vector in the piscine diplomonad Spironucleus vortens. BMC Microbiol 8: 71.
43. Sterud E, Mo TA, Poppe TT (1997) Ultrastructure of Spironucleus barkhanus N. sp. (Diplomonadida: Hexamitidae) from grayling Thymallus thymallus (L.) (Salmonidae) and Atlantic salmon Salmon salar L. (Salmonidae). J Euk Microbiol 44: 399-407.
44. Bassleer G (1983) Disease prevention and control. Spironculeus/Hexamita infection, hole-in-the-head disease. FAMA 6: 38-60.
45. Whaley J, Francis-Floyd R (1991) A comparison of metronidazole treatments for hexamitiasis in angelfsh. Proc IAAAM, pp 110-114.
46. Poynton SL, Fard MR, Jenkins J, Ferguson HW (2004) Ultrastructure of Spironucleus salmonis n. comb. (formerly Octomitus salmonis sensu Moore 1922, Davis 1926, and Hexamita salmonis sensu Ferguson 1979), with a guide to Spironucleus species. Dis Aquat Org 60: 49-64.
47. Moore E (1922) Octomitus salmonis, a new species of intestinal parasite in trout. Trans Am Fisheries Soc 52: 74-97.
48. Davis HS (1926) Octomitus salmonis, a parasitic fagellate of trout. Bull US Bur Fish 42: 9-26.
49. Vickerman K (1990) Phylum Zoomastigophora class Diplomonadida. In: Margulis L, Corliss JO, Melkonian M, Chapman D (eds.), Handbook of Protoctista, Boston, Jones & Barlett, pp 200-210.
50. Jorgensen A, Sterud E (2007) Phylogeny of Spironucleus (Eopharyngia: Diplomonadida: Hexamitinae). Protist 158: 247-254.
51. Uldal A (1996) Life cycle observations on Hexamita salmonis from rainbow trout intestine. In vitro studies. Bull Eur Ass Fish Pathol 16: 112-114.
52. Corliss JO (2001) Protozoan Cysts and Spores. eLS
53. Wood AM, Smith HV (2005) Spironucleosis (Hexamitiasis, Hexamitosis) in the ring-necked pheasant (Phasianus colchicus): detection of cysts and description of Spironucleus meleagridis in stained smears. Avian Dis 49: 138-143.
54. Januschka MM, Erlandsen SL, Bemrick WJ, Schupp DG, Feely DE (1988) A comparison of Giardia microti and Spironucleus muris cysts in the vole: an immunocytochemical, light, and electron microscopic study. J Parasitol 74: 452-458.
55. Koudela B, Karr CD, Meyer EA, Meyer B, Jarroll EL (1996) In vitro excystation of Spironucleus muris. J Euk Microbiol 43: 61-64.
56. Kulda J, Nohynkova E (1978) Flagellates of human intestine and of intestines of other species. In: Kreier JP (ed), Parasitic Protozoa, Vol 2, Academic Press, New York, pp 2-138.
57. Siddall ME, Hong H, Desser SS (1992) Phylogenetic analysis of the Diplomonadida (Wenyon, 1926) Brugerolle, 1975: evidence for heterochrony in protozoa and against Giardia lamblia as a 'missing link'. J Protozool 39: 361-367.
58. Jorgensen A, Torp K, Bjorland MA, Poppe TT (2011) Wild Arctic char Salvelinus alpinus and trout Salmo trutta; hosts and reservoir of the salmonid pathogen Spironucleus salmonicida (Diplomonadida; Hexamitidae). Dis Aquat Org 97: 57-63.
59. Lavier G (1936) Sur la structure des fagellès du genre Hexamita Duj. Societe De Biologie, Paris Comptes Rendus 121: 1177-1180.
60. Brugerolle G, Joyon L, Oktem N (1973) Contribution a l'étude cytologique et phylétique des diplozoaires (Zoomastigophorea, Diplozoa, Dangeard 1910). II Etude ultrastructurale du genre Spironucleus (Lavier 1936). Protistologica IX: 495-502.
61. Sterud E, Poynton SL (2002) Spironucleus vortens (Diplomonadida) in the Ide, Leuciscus idus (L.) (Cyprinidae): a warm water hexamitid fagellate found in northern Europe. J Euk Microbiol 49: 137-145.
62. Xiao W, Li L (1993) Hexamita transparentus sp. nov. and its ultrastructure. Trans Res Fish Dis 1: 52-55.
63. Xiao W, Li L (1994) A light and transmission electron microscopic study of Hexamita capsularis sp. nov. (Diplomonadida: Hexamita) in fsh (Xenocypris divide). Chin J Oceanol Limnol 12: 208-212.
64. Li L, Nie D (1995) Notes on parasitic hexamitids of fshes with descriptions of 18 new species (Zoomastigophores: Diplomonadida: Hexamitidae). Acta Zootaxonomica Sinica 20: 6-28.
65. Xiao W, Wang J, Li L (2002) Descriptions of fve new species of parasitic fagellate belonging to Hexamitidae in fshes. Acta Hydrobiologica Sinica 26: 509-511.
66. Sanghari-Fard MR, Jorgensen A, Sterud E, Bleiss W, Poynton SL (2007) Ultrastructure and molecular diagnosis of Spironucleus salmonis (Diplomonadida) from rainbow trout Oncorhynchus mykiss in Germany. Dis Aquat Org 75: 37-50.
67. Millet COM, Cable J, Hayes A, Hann A, Lloyd D (submitted) Hydrogenosome-like organelles in the diplomonad fsh parasite Spironucleus vortens. J Euk Microbiol.
68. Bui ETN, Bradley PJ, Johnson PJ (1996) A common evolutionary origin for mitochondria and hydrogenosomes. Proc Natl Acad Sci 93: 9651-9656.
69. Andersson JO, Roger AJ (2002) Evolutionary analyses of the small subunit of glutamate synthase: gene order conservation, gene fusions, and prokaryote-to-eukaryote lateral gene transfers. Eukaryot Cell 1: 304-310.
70. Andersson JO, Sjogren AM, Davis LA, Embley TM, Roger AJ (2003) Phylogenetic analyses of diplomonad genes reveal frequent lateral gene transfers affecting eukaryotes. Curr Biol 13: 94-104.
71. Andersson JO, Sjogren AM, Horner DS, Murphy CA, Dyal PL et al (2007) A genomic survey of the fsh parasite Spironucleus salmonicida indicates genomic plasticity among diplomonads and signifcant lateral gene transfer in eukaryote genome evolution. BMC Genomics 8: 51.
72. Kolisko M, Cepicka I, Hampl V, Leigh J, Roger AJ, et al. (2008) Molecular phylogeny of diplomonads and enteromonads based on SSU rRNA, alpha-tubulin and HSP90 genes: Implications for the evolutionary history of the double karyomastigont of diplomonads. BMC Evol Biol 8: 205.
73. Jorgensen A, Alfjorden A, Henriksen K, Sterud E (2007) Phylogenetic analysis of the SSU rRNA gene from the piscine diplomonad Spironucleus torosus (Diplomonadida: Hexamitinae). Folia Parasitol 54: 277-282.
74. Roxstrom-Lindquist K, Jerlstrom-Hultqvist J, Jorgensen A, Troell K, Svard SG (2010) Large genomic differences between the morphologically indistinguishable diplomonads Spironucleus barkhanus and Spironucleus salmonicida. BMC Genomics 11: 258.
75. Andersson JO, Sarchfeld SW, Roger AJ (2004) Gene transfers from nanoarchaeota to an ancestor of diplomonads and parabasalids. Mol Biol Evol 22: 85-90.
76. Andersson JO, Roger AJ (2003) Evolution of glutamate dehydrogenase genes: evidence for lateral gene transfer within and between prokaryotes and eukaryotes. BMC Evol Biol 3: 14.
77. Cavalier-Smith T (1983) A 6-kingdom classifcation and a unifed phylogeny. In: Schwemmler W, Schenk HEA (eds.), Endocytobiology, Berlin: Walter de Gruyter & Co, pp 1027-1034.
78. Clark CG, Roger AJ (1995) Direct evidence for secondary loss of mitochondria in Entamoeba histolytica. Proc Natl Acad Sci USA 92: 6518-6521.
79. Germot A, Philippe H, Le GH (1997) Evidence for loss of mitochondria in Microsporidia from a mitochondrial-type HSP70 in Nosema locustae. Mol Biochem Parasitol 87: 159-168.
80. Embley TM, Hirt RP (1998) Early branching eukaryotes? Curr Opin Genet Dev 8: 624-629.
81. Hashimoto T, Sanchez LB, Shirakura T, Muller M, Hasegawa M (1998) Secondary absence of mitochondria in Giardia lamblia and Trichomonas vaginalis revealed by valyl-tRNA synthetase phylogeny. Proc Natl Acad Sci USA 95: 6860-6865.
82. Tovar J, Fischer A, Clark CG (1999) The mitosome, a novel organelle related to mitochondria in the amitochondrial parasite Entamoeba histolytica. Mol Microbiol 32: 1013-1021.
83. Tovar J, Leon-Avila G, Sanchez LB, Sutak R, Tachezy J, et al. (2003) Mitochondrial remnant organelles of Giardia function in iron-sulphur protein maturation. Nature 426: 172-176.
84. Maiden MC (2006) Multilocus sequence typing of bacteria. Annu Rev Microbiol 60: 561-588.
85. Simpson AGB (2003) Cytoskeletal organization, phylogenetic affnities and systematics in the contentious taxon Excavata (Eukaryota). Int J Syst Evol Microbiol 53: 1759-1777.
86. Keeling PJ, Doolittle WF (1996) A non-canonical genetic code in an early diverging eukaryotic lineage. Embo Journal 15: 2285-2290.
87. Keeling PJ, Doolittle WF (1996) Alpha-tubulin from early-diverging eukaryotic lineages and the evolution of the tubulin family. Mol Biol Evol 13: 1297-1305.
88. Kolisko M, Cepicka I, Hampl V, Kulda J, Flegr J (2005) The phylogenetic position of enteromonads: a challenge for the present models of diplomonad evolution. Int J Syst Evol Microbiol 55: 1729-1733.
89. Keeling PJ, Brugerolle G (2006) Evidence from SSU rRNA phylogeny that Octomitus is a sister lineage to Giardia. Protist 157: 205-212.
90. Kulda J, Lom J (1964) Remarks on the diplomastigine fagellates from the intestine of fshes. Parasitology 54: 753-762.
91. Rottmann RE, Francis-Floyd, Durborow R (1992) The role of stress in fsh disease. SRAC Publication No. 474.
92. Francis-Floyd R, Reed P (1994) Management of Hexamita in Ornamental Cichlids. UF/IFAS Fact Sheet VM-67.
93. Meseck EK, French TW, Grimmett SG, Bartlett SL, Wooster GA, et al. (2007) Gross and microscopic pathology associated with large cavernous lesions in muscle of chinook salmon from Lake Ontario. J Wildl Dis 43: 111-115.
94. Uldal A, Buchman K (1996) Parasite host relations: Hexamita salmonis in rainbow trout Oncorhynchus mykiss. Dis Aquat Org 25: 229-231.
95. Saghari Fard MR, Weisheit C, Poynton SL (2007) Intestinal pH profle in rainbow trout Oncorhynchus mykiss and microhabitat preference of the fagellate Spironucleus salmonis (Diplomonadida). Dis Aquat Org 76: 241-249.
96. Buchmann K, Uldal A (1996) Temperature, pH and bile dependent in vitro cultivation of Hexamita salmonis from rainbow trout Oncorhynchus mykiss intestine. Dis Aquat Org 24: 169-172.
97. Lom J, Dykova I (1992) Developments in aquaculture and fsheries science, Vol 26. Protozoan parasites of fshes. Elsevier, Amsterdam.
98. Uzmann JR, Jesse JW (1963) The Hexamita (=Octomitus) problem: a preliminary report. Prog Fish Cult 25: 141-143.
99. Uzmann, JR, Paulik GJ, Hayduk SH (1965) Experimental hexamitiasis in juvenile coho salmon (Oncorhynchus kisutch) and steelhead trout (Salmo gairdneri). Trans Am Fish Soc 94: 53-61.
100. Fagerholm HP, Bylund G (1997) Is Hexamita salmonis (fagellata) causing widespread systemic disease in fsh? Bull Scand Soc Parasitol 5: 33-34.
101. Sangmaneedet S, Smith SA (2000) In vitro studies on the optimal requirements for the growth of Spironucleus vortens, an intestinal parasite of the freshwater angelfsh. Dis Aquat Org 39: 135-141.
102. Millet COM, Lloyd D, Williams C, Cable J (2010) In vitro culture of the diplomonad fsh parasite Spironucleus vortens reveals unusually fast doubling time and a typical biphasic growth. J Fish Dis 34: 71-73.
103. Millet COM, Cable J, Lloyd D (2010) The diplomonad fsh parasite Spironucleus vortens produces hydrogen. J Euk Microbiol 57: 400-404.
104. Horner DS, Hirt RP, Kilvington S, Lloyd D, Embley TM (1996) Molecular data suggest an early acquisition of the mitochondrion endosymbiont. Proc Roy Soc B 263: 1053-1059.
105. Lloyd D, Lindmark DG, Muller M (1979) Respiration of Tritrichomonas foetus: absence of detectable cytochromes. J Parasitol 65: 466-469.
106. Lloyd D, Lindmark DG, Muller M (1979) Adenosine triphosphatase activity of Tritrichomonas foetus. J Gen Microbiol 115: 301-307.
107. Horner DS, Foster PG, Embley TM (2000) Iron hydrogenases and the evolution of anaerobic eukaryotes. Mol Biol Evol 17: 1695-1709.
108. Chapman A, Cammack R, Linstead DJ, Lloyd D (1986) Respiration of Trichomonas vaginalis: components detected by electron paramagnetic resonance spectroscopy. Eur J Biochem 156: 193-198.
109. Lloyd D, Kristensen B (1985) Metronidazole inhibition of hydrogen production in vivo in drug-sensitive and resistant strains of Trichomonas vaginalis. J Gen Microbiol 131: 849-853.
110. Millet COM (2009) Growth, metabolism, ultrastructure and chemotherapy of Spironucleus vortens. Unpublished PhD thesis, Cardiff University.
111. Millet COM, Lloyd D, Coogan MP, Rumsey J, Cable J (2011) Carbohydrate and amino acid metabolism of Spironucleus vortens. Exp Parasitol 129: 17-26.
112. Biagini GA, Yarlett N, Ball GE, Billetz AC, Lindmark DG, et al. (2003) Bacterial-like energy metabolism in the amitochondriate protozoon Hexamita infata. Mol Biol Parasitol 128: 11-19.
113. Post G (1987) Textbook of fsh health. TFH Publications, Neptune City, New Jersey.
114. Sangmaneedet S, Smith SA (1999) Effcacy of various chemotherapeutic agents on the growth of Spironucleus vortens, an intestinal parasite of the freshwater angelfsh. Dis Aquat Organ 38: 47-52.
115. Freeman CD, Klutman NE, Lamp KC (1997) Metronidazole. A therapeutic review and update. Drugs 54: 679-708.
116. Edwards DI (1993) Nitroimidazole drugs - action and resistance mechanisms. II. Mechanism of resistance. JAC 31: 201-210.
117. L82/14 CRE (1998) Veterinary drug residues: regulatory issues.
118. Lanzky PF, Halling-Sorensen B (1997) The toxic effect of the antibiotic metronidazole on aquatic organisms. Chemosphere 11: 2553-2561.
119. Kummerer K, Al-Ahmad A, Mersch-Sundermann V (2000) Biodegradability of some antibiotics, elimination of the genotoxicity and affection of waste water bacteria in a simple test. Chemosphere 40: 701-710.
120. Jjemba PK (2002) The effect of chloroquine, quinacrine and metronidazole on both soybean plants and soil microbiota. Chemosphere 46: 1019-1025.
121. Cavas T, Ergene-Gozukara S (2005) Genotoxicity evaluation of metronidazole using the piscine micronucleus test by acridine orange staining. Environ Toxicol Phar 1: 107-111.
122. Khalil WKB, Mahmoud MA, Zahran MM, Mahrous KF (2007) A sub-acute study of metronidazole toxicity assessed in Egyptian Tilapia zillii. J Appl Toxicol 27: 380-390.
123. IARC (1987) Evaluation of carcinogenetic risk to humans. IARC 7: 250-251.
124. FARAD (2010) USA Food and Drug Administration.
125. Williams CF, Lloyd D (in press) Composition and antimicrobial properties of sulphur-containing constituents of garlic (Allium sativum). In: Valgimigli L (ed.) Essential oils as natural food additives, Nova Science Publishers Inc.
126. Millet COM, Lloyd D, Williams CF, Williams D, Evans G, et al. (2010) Effect of garlic and Allium-derived products on the growth and metabolism of Spironucleus vortens. Exp Parasitol 127: 490-499.
127. Liltved H, Hektoen H, Efraimsen H (1995) Inactivation of bacterial and viral fsh pathogens by ozonation or UV irradiation in water of different salinity. Aquacult Eng 13: 107-122.
128. Andrews C (1990) The ornamental fsh trade and fsh conservation. J Fish Biol 37: 53-59.
129. Seligo A (1887) Untersuchungen über Flagellaten. Beitr Biol Pfz 4: 145-180.