Iranian Journal of Veterinary Medicine

IJVM (2014), 8(1):59-62 59

Visceral coccisdiosis in a common mynah (Acridotheres tristis)due to Isospora sp. infection Arabkhazaeli, F.1*, Madani, S.A.2

1Department of Parasitology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran2Department of Avian Diseases, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran

Case History

A captive adult common mynah (Acridotherestristis) was referred with a history of severe lethargy,depression, and loss of appetite. Clinical signs andhistopathological findings associated with Isospora(Atoxoplasma) infection in a common mynah in Iranare described.

Clinical Presentations

Abdominal distention and hepatomegaly wereclinically visible over the abdominal skin. Polyurateand urate discoloration were noticed. The bird diedshortly after a course of seizure and opisthotonous.

Diagnostic Tests

At necropsy, severe enlargement of liver with

general discoloration of both lobes, as distribution ofpale and congested areas, was observed (Figure 1).Intestinal distension especially in duodenum alongwith moderate thickening of the intestinal mucosawas obvious.

Liver cytology revealed typical vacuolization ofthe hepatocytes and large number of inflammatorycells especially macrophages containing circularlight blue objects with purple-red center resemblingAtoxoplasma zoites caused indention of the cells'nuclei (Figure 2A). The same intracytoplasmicparasites were seen in the lung and the spleenimpression smears; however, the number of infectedcells were typically lower in these two organs(Figures 2 B & C). Some degrees of erythrocytepolychromasia were seen in the lung cytology. Inhistological section of the liver, hepatocytevacuolization, severe disseminated necrosis withoutparticular lobular pattern, and parasitic interacyto-plasmic inclusion bodies were numerously noted.

Key words:

Atoxoplasma, Isospora, pet bird,visceral coccidiosis

Correspondence

Arabkhazaeli, F.Department of Parasitology, Facultyof Veterinary Medicine, University ofTehran, Tehran, IranTel: +98(21) 61117049Fax: +98(21) 66933222Email: farab@ut.ac.ir

Received: 24 November 2013Accepted: 12 February 2014

Abstract:

A captive adult common mynah (Acridotheres tristis) diedshortly after a course of seizure and opisthotonous with an illnesscharacterized by severe lethargy, depression, loss of appetite,polyurate, and urate discoloration. Abdominal distention andhepatomegly, visible over the abdominal skin, were noticedclinically. At necropsy, severe enlargement of liver with generaldiscoloration was obvious. Histopathological findings includedschizonts and gametes in the intestine, especially in theduodenum. Cytology from impression smears revealed intracyto-plasmic Atoxoplasma-like zoites in the inflammatory cellsespecially macrophages within the liver and in the contactsmears prepared from the liver, lung, and spleen. Based onpostmortem findings of the organisms in blood mononuclearcells and in impression smears of liver and Giemsa stainedimpression smears of liver, the spleen and lung atoxoplasmosiscaused by Isoapora sp. was specified as the cause of death.According to the literature, visceral coccidiosis (atoxo-plasmosis), described here, could be considered as one of thesevere causes of mortality among captive birds.

The parasites were also observed in the sectionderived from spleen. The presence of schizonts andgametocytes in the intestine, especially in theduodenum was recorded (Figure 2D).

Assessments

Atoxoplasma-like infections have been reportedin several species of passerine birds, includinggreenfinches (Carduelis chloris), house sparrows(Passer domesticus), Bali mynahs (Leucopsarrothschildi), bullfinches (Pyrrhula pyrrhula),canaries (Serinus canaria) (Martinez and Munoz,1998; Sa´nchez-Cordo´n et al., 2007; Maslin andLatimer, 2009), and rarely in raptors (Remple, 2004).To the best knowledge of the authors, there were noreports of atoxoplasmosis (with extra-intestinalmerogony) from Iran, and up until now in the worldin common mynah. There are reports of Isoporaspecies from birds of the Sturnidae family, solely

identified on the basis of the morphology of theoocysts in the feces and no Atoxoplasma-likeorganisms were found in the blood smears (Berto etal., 2011); as was the case for Tavasoli and Dastjerd(2000) who detected Isosporan oocysts in %47.6 ofexamined canary feces; however, they could not findmononuclear merozoites at necropsy.

Atoxoplasmosis, the cause of frequent mortalitiesamong captive pet birds, is sometimes called "goinglight" as infected birds may stop eating and loseweight (Greiner, 2008). Affected birds have heavyextraintestinal merogonic infection (Gill andPaperna, 2008), often accompanied by the presenceof fecal oocysts (Greiner, 2008). Following theingestion of isosporoid (disporous tetrazoic) oocysts,coccidiosis due to Isospora (formerly known asAtoxoplasma) occurs in passerine birds, with a lifecycle including invasion to both the reticulo-endothelial system and the intestinal epithelium(Pereira et al., 2011; Schrenzel et al., 2005; Adkessonet al., 2005). Merogony (asexual reproduction)occurs in both intestinal and lymphoid-macrophagecells, resulting in the presence of merozoites in themononuclear leukocytes of the peripheral blood anddissemination to other viscera. Gametogenesisoccurs in the intestinal cells of the same host(Adkesson et al., 2005). Some species of amongmany described Isospora species from birds haveendogenous stages only in small intestine epithelium,while other species form extraintestinal stages inmononuclear phagocytes in different organs. Thespecies with extraintestinal stages were suggested tobe named Atoxoplasma (Dolnik et al., 2009).However until now, it has been sugessted thatIsospora spp. and Atoxoplasma spp. in passerinebirds are a unified group of organisms with intestinaland extra-intestinal forms that cause significantmorbidity and mortality (Schrenzel et al., 2005).Atoxoplasma infections have been diagnosed usinghistopathologic examination of tissue samples, buffycoat smears, impression smears of organs,transmission electron microscopy and polymerasechain reaction (PCR) analysis (Adkesson et al., 2005;Greiner, 2008; Remple, 2004). Definitive taxonomicclassification of Isospora remained ambiguous formany years and still there are many elusive aspects ofthe parasite pathobiology, namely the clonalexpansion of the infected lymphocytes (Maslin and

Visceral coccisdiosis in a common mynah... Arabkhazaeli, F.

IJVM (2014), 8(1):59-6260

Figure 1. Severe enlargement of the liver with generaldiscoloration of both lobes.

Latimer, 2009). Identification of avian coccidian species is mainly

based on oocysts morphology. However, regardingmolecular methods, DNA derived from both specieshaving intestinal and extra-intestinal life cycle maybe present in pooled fecal samples, which limits thestrength of PCR as a single diagnostic tool in speciesdetermination (Adkesson et al., 2005; Dolnik et al.,2009).

Considering the non-specific symptoms andsmall size of the parasite, diagnosis of Atoxoplasmainfection is challenging. The organism may be easilymissed, especially in low-grade subclinical infec-tions (Adkesson et al., 2005), like the case for whichwe did not have the oocysts, and species determin-ation was impossible.

Antemortem diagnosis of atoxoplasmosis isgenerally based on the finding of swollen and darken-

ed liver through the skin, the organisms in bloodmononuclear cells and less practically in impressionsmears of liver biopsy. At necropsy, Giemsa stainedimpression smears of liver, spleen, heart, or pancreasprovide an effective means of diagnosis (Maslin andLatimer, 2009). As reported, standard anticoccidialdrugs are ineffective against the tissue stages of theparasite, but sulfachlorpyrazine appears to decreaseoocysts output in the adults, which will minimizeexposure and infection in young birds. Cleanliness isalso important in minimizing exposure to the oocysts(Maslin and Latimer, 2009; Adkesson et al., 2005). Itis necessary for the veterinarians to consider thesymptoms of visceral coccidiosis as a cause of illnessin pet and wild passerines.

Iranian Journal of Veterinary MedicineArabkhazaeli, F.

IJVM (2014), 8(1):59-62 61

Figure 2. Impression smears of the liver, lung and spleen and histopathologic section of the duodenum from a naturally-infected commonmynah: (A) Impression smear of the liver. Note the typical vacuolization of the hepatocytes and Atoxoplasma zoites (thin arrows) causingindention of the cells' nuclei (thick arrow) (1000x), (B) Impression smear of the lung. Atoxoplasma zoite (arrow) within a macrophage(1000x), (C) Spleen cytology. Atoxoplasma zoites (arrows) are clearly visible (1000x), (D) Histologic section of the intestine (H&E).Gametocytes (arrows) are shown in the intestinal mucosa (400x).

Visceral coccisdiosis in a common mynah... Arabkhazaeli, F.

IJVM (2014), 8(1):59-6262

Tavasoli, M., Dastjerd, A. (2000) Gastrointestinal

parasite of aviary and pet birds in Urimia, Iran.

Pajuhesh Va Sazandegi (In persian). 62: 37-39.

12.

Adkesson, M.J., Zdziarski, J.M., Little, S.E. (2005)

Atoxoplasmosis in tanagers. J Zoo Wildl Med. 36:

265-272.

Berto, P.B., Flausino, W., McIntosh, D., Teixeira-

Filho, W.L., Lppes, C.W.G. (2011) Coccidia of new

world passerine birds (Aves: Passeriformes): a

review of Eimeria and Isospora Schneider, 1881

(Apicomplexa: Eimeriidae). Syst Parasitol. 80: 159-

204.

Dolnik, O.V., Palinauskas, V., Bensch, S. (2009)

Individual oocysts of isospora (Apicomplexa:

Coccidia) parasites from avian feces: from photo to

sequence. J Parasitol. 95: 169-174.

Gill, H., Paperna, I. (2008) Proliferative visceral

isoapora (atoxoplasmosis) with morbid impact on the

Israeli sparrow Passser domesticus biblicus Hartert,

1904. Parasitol Res. 103: 493-499.

Greiner, E.C. (2008) Isospora, Atoxoplasma, and

Sarcocystis. In: Parasitic Diseases of Wild Birds.

Atkinson, C.T., Thomas, N.J., Hunter, D.B. (eds.).

Wiley-Blackwell, Ames, Iowa, USA. p. 108-119.

Martinez, F., Munoz, E. (1998) Atoxoplasma spp. in a

hybrid passerine (Serinus canaries×Carduelis

cannabina). Avian Pathol. 27: 420-422.

Maslin, W.R., Latimer, K.S. (2009) Atoxoplasmosis

in canary fledglings: severe lymphocytic enteritis

with preferential parasitism of B lymphocytes. Avian

Dis. 53: 473-476.

Pereira, L.Q., Berto, B.P., Flausino, W., Lovato, M.,

Lopes, C.W.G. (2011) Isospora bocamontensis n. sp.

(Apicomplexa: Eimeriidae) from the yellow cardinal

Gubernatrix cristata (Vieillot) (Passeriformes:

Emberizidae) in South America. Syst Parasitol. 78:

73-80.

Remple, J.D. (2004) Intracellular hematozoa of

raptors: A review and update. J Avian Med Surg. 18:

75-88.

Sa´nchez-Cordo´n, P.J., Go´mez-Villamandos, J.C.,

Gutie´rrez1, J., Sierra, M.A., Pedrer, M., Bautista,

M.J. (2007) Atoxoplasma spp. infection in captive

canaries (Serinus canaria). J Vet Med A. 54: 23-26.

Schrenzel, M.D., Maalouf, G.A., Gaffney, P.M.,

Tokarz, D., Keener, L.L., McClure, D., Griffey, S.,

McAloose, D., Rideout, B.A. (2005) Molecular

characterization of isosporoid coccidia (Isospora and

Atoxoplasma spp.) in passerine birds. J Parasitol. 91:

635-647.

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References

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Abstracts in Persian Language

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