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Epidemiological, clinical and diagnostic aspects of sheep conidiobolomycosis in Brazil

Aspectos epidemiológicos, clínicos e de diagnóstico da conidiobolomicose ovina no Brasil

ABSTRACT:

Conidiobolomycosis is an emerging disease caused by fungi of the cosmopolitan genus Conidiobolus . Particular strains of Conidiobolus coronatus, Conidiobolus incongruus and Conidiobolus lamprauges , mainly from tropical or sub-tropical origin, cause the mycosis in humans and animals, domestic or wild. Lesions are usually granulomatous and necrotic in character, presenting two clinical forms: rhinofacial and nasopharyngeal. This review includes the main features of the disease in sheep, with an emphasis on the epidemiology, clinical aspects, and diagnosis of infections caused byConidiobolus spp. in Brazil. In this country, the disease is endemic in the Northeast and Midwest, affecting predominantly woolless sheep breeds and occasioning death in the majority of the studied cases. The species responsible for infections of sheep areC. coronatus andC. lamprauges and the predominant clinical presentation is nasopharyngeal. These fungal infections are very important, since they compromise the health status of the sheep flock and cause serious economic losses to the sheep industry. Thus, research is needed to investigate faster tools for diagnosis and effective methods for the control and treatment of conidiobolomycosis.

Key words:
Fungal infection; ovine; zygomycosis; Conidiobolus spp .

RESUMO:

Conidiobolomicose é uma enfermidade emergente causada por fungos cosmopolitas do gênero Conidiobolus . Isolados deConidiobolus coronatus, Conidiobolus incongruus eConidiobolus lamprauges, principalmente de origem tropical e subtropical, afetam humanos, animais domésticos e silvestres. As lesões da conidiobolomicose normalmente são de caráter granulomatoso e necrótico, apresentando-se sob duas formas clínicas: rinofacial e nasofaríngea. O presente artigo tem como objetivo revisar as principais características da doença em ovinos, particularizando a epidemiologia, assim como os aspectos clínicos e o diagnóstico das infecções causadas porConidiobolus spp. no Brasil. Neste País, a enfermidade é endêmica nas regiões nordeste e centro-oeste, afetando ovinos predominantemente de raças deslanadas, ocasionando a morte na grande maioria dos casos estudados. As espécies do fungo responsáveis pelas infecções em ovinos são C. coronatus eC. lamprauges e a forma clínica predominante é a nasofaríngea. Tais infecções fúngicas são muito importantes, uma vez que comprometem o status sanitário do rebanho ovino e acarretam sérios prejuízos econômicos à ovinocultura. Dessa forma, pesquisas são necessárias para investigar ferramentas rápidas de diagnóstico e métodos eficazes de controle e tratamento da conidiobolomicose.

Palavras-chave:
micose; ovino; zigomicose; Conidiobolus spp.

INTRODUCTION:

Conidiobolomycosis is considered an emerging disease caused by several species of fungi of the cosmopolitan genus Conidiobolus in phylum Entomophthoromycota. The latter in one of six major phylogenetic lineages recognised among the former phylum Zygomycota (GRIGANSKI et al., 2013). Pathogenic Conidiobolus species infects human beings (TADANO et al., 2005TADANO, T. et al. Entomoftoromicose (zigomicose) causada por Conidiobolus coronatus em Mato Grosso (Brasil): relato de caso.Revista da Sociedade Brasileira de Medicina Tropical, v. 38, n. 2, p. 188-190, 2005. Available from: <Available from: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0037-86822005000200013 >. Accessed: May 20, 2015. doi: 10.1590/S0037-86822005000200013.
http://www.scielo.br/scielo.php?script=s...
;MICHAEL et al., 2009MICHAEL, R.C. et al. Unusual presentation of entomophthoromycosis. Indian Journal of Medical Microbiology, v. 27, n. 2, p.156-158, 2009. Available from: <Available from: http://www.ijmm.org/article.asp?issn=02550857;year=2009;volume=27;issue=2;spage=156;epage=158;aulast=Michael >. Accessed: May 20, 2015. doi: 10.4103/0255-0857.49432.
http://www.ijmm.org/article.asp?issn=025...
; KIMURA et al., 2011KIMURA, M. et al. Disseminated human conidiobolomycosis due to Conidiobolus lamprauges., Journal of Clinical Microbiology v.49, n.2, p.752-756, 2011. Available from: <Available from: http://jcm.asm.org/content/49/2/752.full >. Accessed: May 20, 2015. doi: 10.1128/JCM.01484-10.
http://jcm.asm.org/content/49/2/752.full...
; BACHELET et al., 2014BACHELET, J.T. et al. Infection à Conidiobolus coronatus révélée par une tumeur de la face. Revue de Stomatologie, de Chirurgie Maxillo-faciale et de Chirurgie Orale, v.115, n.2, p.114-117, 2014. Available from: <Available from: http://www.sciencedirect.com/science/article/pii/S2213653313002759 >. Accessed: May 20, 2015. doi: 10.1016/j.revsto.2013.12.003.
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) as well as various species of domestic and wild animals (Table 1). The majority of Conidiobolus are non-pathogenic saprobes or opportunistic pathogens of arthropods and occur worldwide, but Conidiobolus coronatus , Conidiobolus incongruus and Conidiobolus lamprauges are the most frequent etiological agents of the conidiobolomycosis. Their pathogenic strains occur mainly in tropical and subtropical regions, in areas of high humidity, particularly in Africa (EL-SHABRAWI et al., 2014EL-SHABRAWI, M. H. F. et al. Entomophthoromycosis: a challenging emerging disease. Mycoses, v. 57, Suppl. 3, p.132-137, 2014. Available from: <Available from: http://onlinelibrary.wiley.com/doi/10.1111/myc.12248/epdf >. Accessed: Sept. 18, 2015.
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); however, cases have been reported worldwide (Table 1), including Brazil (Table 2).

Table 1
Reported cases of conidiobolomycosis in animal species from outside Brazil.
Table 2
Epidemiological and clinical aspects of ovine conidiobolomycosis outbreaks reported in Brazil, 1979-2014.

Conidiobolomycosis is characterized by granulomatous and necrotic lesions and it shows two clinical manifestations: rhinofacial and nasopharyngeal infection (SILVA et al., 2007aSILVA, S.M.M.S. Epidemiology and symptoms of conidiobolomycosis in sheep in the State of Piauí, Brazil. Pesquisa Veterinária Brasileira,v.27, n.4, p.184-190,2007a. Available from: <Available from: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-736X2007000400010 >. Accessed: May 20, 2015. doi: 10.1590/S0100-736X2007000400010.
http://www.scielo.br/scielo.php?script=s...
,b; RIET-CORREA et al., 2008RIET-CORREA, F. et al. Outbreaks of rhinofacial and rhinopharyngeal zygomycosis in sheep in Paraíba, northeastern Brazil. Pesquisa Veterinária Brasileira, v. 28, n. 1, p. 29-35, 2008. Available from: <Available from: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-736X2008000100005 >. Accessed: May 20, 2015. doi: 10.1590/S0100-736X2008000100005.
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). In recent years, there is an increasing number of case reports of disease affecting woolless sheep flocks in Brazil, especially in the Northeast and Midwest regions (Table 2). This fact evidences that the epidemiological conditions in the country are favorable for proliferation and maintenance of the fungus in the environment.

Brazilian sheep industry is becoming increasingly widespread and it is characterized by two aspects of production, including meat and skin (mainly the Northeast region) and meat and wool (especially in the South region) (IBGE, 2002IBGE (INSTITUTO BRASILEIRO DE GEOGRAFIA E ESTATÍSTICA). Available from: <Available from: http://www.ibge.gov.br/home/estatistica/economia/agropecuaria/censoagro/default.shtm >. Accessed: May 20, 2015.
http://www.ibge.gov.br/home/estatistica/...
). The conidiobolomycosis in sheep flocks compromises the health status of the herd and causes economic losses to sheep breeding, since mortality and lethality rates reach 100% (SILVA et al., 2007aSILVA, S.M.M.S. Epidemiology and symptoms of conidiobolomycosis in sheep in the State of Piauí, Brazil. Pesquisa Veterinária Brasileira,v.27, n.4, p.184-190,2007a. Available from: <Available from: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-736X2007000400010 >. Accessed: May 20, 2015. doi: 10.1590/S0100-736X2007000400010.
http://www.scielo.br/scielo.php?script=s...
,b; RIET-CORREA et al., 2008RIET-CORREA, F. et al. Outbreaks of rhinofacial and rhinopharyngeal zygomycosis in sheep in Paraíba, northeastern Brazil. Pesquisa Veterinária Brasileira, v. 28, n. 1, p. 29-35, 2008. Available from: <Available from: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-736X2008000100005 >. Accessed: May 20, 2015. doi: 10.1590/S0100-736X2008000100005.
http://www.scielo.br/scielo.php?script=s...
, MENDONÇA et al., 2012MENDONÇA, F.S. et al.Conidiobolomycosis in sheep in the state of Pernambuco. Revista Brasileira de Medicina Veterinária, v. 34, n. 3, p. 241-246, 2012. Available from: <Available from: http://www.rbmv.com.br/pdf_artigos/07-11-2012_10-42RBMV%20015.pdf >. Accessed: May 20, 2015.
http://www.rbmv.com.br/pdf_artigos/07-11...
; AGUIAR et al., 2014AGUIAR, G.M.N. et al. Epidemiological aspects of conidiobolomycosis in sheep in the Northeastern Brazilian semiarid region. Ciência Rural, v.44, n.12, p.2210-2216, 2014. Available from: <Available from: http://dx.doi.org/10.1590/0103-8478cr20131472 >. Accessed: June 30, 2015. doi: 10.1590/0103-8478cr20131472.
http://dx.doi.org/10.1590/0103-8478cr201...
). These issues justify the concern about the occurrence of the disease in Brazilian sheep herds. Thus, this review describes the main epidemiological and clinical features, as well as the diagnostic methods relevant to conidiobolomycosis in sheep in Brazil.

Etiological agents

Conidiobolus genus belongs to the kingdom Fungi, Phylum Entomophthoramycota and Entomophthorales order (GRIGANSKI et al., 2013GRYGANSKI, A. P. et al. Phylogenetic lineages in Entomophthoromycota. Persoonia, v. 30, n. 1, p.94-105, 2013. Available from: <Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3734969/ >. Accessed: Sept. 15, 2015. doi: 10.3767/003158513X666330.
http://www.ncbi.nlm.nih.gov/pmc/articles...
). Morphologically, Conidiobolus spp. have hyaline, coenocytic hyphae or shorter hyphal bodies, although septa may be more infrequentthanl the older parts of the mycelium (CHAYAKULKEEREE et al., 2006CHAYAKULKEEREE, M. et al. Zygomycosis: the re-emerging fungal infection. European Journal of Clinical Microbiology & Infectious Diseases, v. 25, n.4, p.215-229, 2006. Available from: <Available from: http://link.springer.com/article/10.1007/s10096-006-0107-1 >. Accessed: May 20, 2015.
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). Rounded dilations are often seen at the ends of hyphae and these enlargements have been also described in case of conidiobolomycosis (KETTERER et al., 1992KETTERER, P.J. et al. Rhinocerebral and nasal zygomycosis in sheep caused by Conidiobolus incongruus., Australian Veterinary Journal v. 69. n. 4, p. 85-87, 1992.; SILVA et al., 2007bSILVA, S.M.M.S. et al. Conidiobolomycosis in sheep in Brazil. Veterinary Pathology, v. 44, n. 3, p. 314-319, 2007b. Available from: <Available from: http://vet.sagepub.com/cgi/pmidlookup?view=long&pmid=17491072 >. Accessed: May 20, 2015.
http://vet.sagepub.com/cgi/pmidlookup?vi...
, BOABAID et al., 2008BOABAID, F. M. et al. Conidiobolomycosis in sheep in the state of Mato Grosso, Brazil. Pesquisa Veterinária Brasileira, v.28, n.1, p.777-781, 2008. Available from: <Available from: http://www.scielo.br/scielo.php?pid=S0100-736X2008000100012&script=sci_arttext >. Accessed: May 20, 2015. doi: 10.1590/S0100-736X2008000100012.
http://www.scielo.br/scielo.php?pid=S010...
). These fungi are characterized by producing asexual spores, which are relatively large globose conidia borne singly on conidiophores and forcibly discharged. In general, these conidia have basal buds (papillae ) with rounded and prominent shape (SIDRIM & ROCHA et al., 2008SIDRIM, J.J.C.; ROCHA, M.F.G. Micologia médica a luz de autores contemporâneos. Rio de Janeiro. Guanabara Koogan. 408p, 2008. ). However, sexual spores (zygospores) in cultures are different among the three known mammalian pathogenic Conidiobolus species. C. lamprauges has smaller zygospore than C. incongruus and has often only a single large homogeneous globule inside the mature conidia. Conversely, C. incongruus has various small globules inside it's mature conidia. In C. coronatus zygospore are absent (VILELA et al., 2010VILELA, R. et al. Morphologic and phylogenetic characterization of Conidiobolus lamprauges recovered from infected sheep., Journal of Clinical Microbiology v. 48, n. 2, p. 427-432, 2010. Available from: <Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2815615/pdf/1589-09.pdf >. Accessed: May 20, 2015. doi: 10.1128/JCM.01589-09.
http://www.ncbi.nlm.nih.gov/pmc/articles...
), but sometimes characteristic villose resistant spores are formed by conidia.

Species of Conidiobolus pathogens have the ability to assimilate carbohydrates and grows well at 37°C (CHAYAKULKEEREE et al., 2006CHAYAKULKEEREE, M. et al. Zygomycosis: the re-emerging fungal infection. European Journal of Clinical Microbiology & Infectious Diseases, v. 25, n.4, p.215-229, 2006. Available from: <Available from: http://link.springer.com/article/10.1007/s10096-006-0107-1 >. Accessed: May 20, 2015.
http://link.springer.com/article/10.1007...
). SILVA et al. (2012SILVA, J.A.G. et al. Thermoregulated genes differentially expressed in Conidiobolus lamprauges., Ciência Rural v.42, n. 9, p. 1610-1613, 2012. Available from: <Available from: http://www.scielo.br/scielo.php?pid=S0103-84782012000900015&script=sci_arttext >. Accessed: May 20, 2015. doi: 10.1590/S0103-84782012005000064.
http://www.scielo.br/scielo.php?pid=S010...
) also reported that C. lamprauges when exposed to temperature of 37°C overexpresses enolase, suggesting that this enzyme has potential involvement in host-pathogen relationship and virulence of this fungus. GODOY et al. (2014GODOY, I. et al. Differential expression of protein of the fungus Conidiobolus lamprauges cultivated at different temperatures. Ciencia Rural, v. 44, n. 3, p. 473-478, 2014. Available from <Available from http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782014000300014&lng=en&nrm=iso >. Accessed: Sept. 15, 2015. doi: 10.1590/S0103-84782014000300014.
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) suggest that C. lamprauges produces a range of proteins that are related to thermoregulation triggered by the high temperature of the host.

Epidemiology

Conidiobolomycosis cases were described in tropical regions such as: Africa, South America, Central America, and Asia (CHAYAKULKEEREE et al., 2006CHAYAKULKEEREE, M. et al. Zygomycosis: the re-emerging fungal infection. European Journal of Clinical Microbiology & Infectious Diseases, v. 25, n.4, p.215-229, 2006. Available from: <Available from: http://link.springer.com/article/10.1007/s10096-006-0107-1 >. Accessed: May 20, 2015.
http://link.springer.com/article/10.1007...
; EL-SHABRAWI et al., 2014EL-SHABRAWI, M. H. F. et al. Entomophthoromycosis: a challenging emerging disease. Mycoses, v. 57, Suppl. 3, p.132-137, 2014. Available from: <Available from: http://onlinelibrary.wiley.com/doi/10.1111/myc.12248/epdf >. Accessed: Sept. 18, 2015.
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). In Brazil, the disease is considered endemic in flocks of the Northeast and Midwest regions, being reported in ovine in the states of Piauí (SILVA et al., 2007aSILVA, S.M.M.S. Epidemiology and symptoms of conidiobolomycosis in sheep in the State of Piauí, Brazil. Pesquisa Veterinária Brasileira,v.27, n.4, p.184-190,2007a. Available from: <Available from: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-736X2007000400010 >. Accessed: May 20, 2015. doi: 10.1590/S0100-736X2007000400010.
http://www.scielo.br/scielo.php?script=s...
,b), Paraíba (RIET-CORREA et al., 2008RIET-CORREA, F. et al. Outbreaks of rhinofacial and rhinopharyngeal zygomycosis in sheep in Paraíba, northeastern Brazil. Pesquisa Veterinária Brasileira, v. 28, n. 1, p. 29-35, 2008. Available from: <Available from: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-736X2008000100005 >. Accessed: May 20, 2015. doi: 10.1590/S0100-736X2008000100005.
http://www.scielo.br/scielo.php?script=s...
), Pernambuco (MENDONÇA et al., 2012MENDONÇA, F.S. et al.Conidiobolomycosis in sheep in the state of Pernambuco. Revista Brasileira de Medicina Veterinária, v. 34, n. 3, p. 241-246, 2012. Available from: <Available from: http://www.rbmv.com.br/pdf_artigos/07-11-2012_10-42RBMV%20015.pdf >. Accessed: May 20, 2015.
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), and Mato Grosso (BOABAID et al., 2008BOABAID, F. M. et al. Conidiobolomycosis in sheep in the state of Mato Grosso, Brazil. Pesquisa Veterinária Brasileira, v.28, n.1, p.777-781, 2008. Available from: <Available from: http://www.scielo.br/scielo.php?pid=S0100-736X2008000100012&script=sci_arttext >. Accessed: May 20, 2015. doi: 10.1590/S0100-736X2008000100012.
http://www.scielo.br/scielo.php?pid=S010...
; DE PAULA et al., 2010DE PAULA, D. A. J. et al. Molecular characterization of ovine zygomycosis in central western Brazil. Journal of Veterinary Diagnostic Investigation, v. 22, n. 2, p. 274-277, 2010. Available from: <Available from: http://vdi.sagepub.com/content/22/2/274.long >. Accessed: May 20, 2015.
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). Sporadic cases were also reported in ovine in the Southern region, in the states of Santa Catarina (FURLAN et al., 2010FURLAN, F. H. et al. Conidiobolomycosis caused by Conidiobolus lamprauges in sheep in the state of Santa Catarina, Brazil. Pesquisa Veterinária Brasileira,v.30, n.7, p.529-532,2010. Available from: <Available from: http://www.scielo.br/scielo.php?pid=S0100-736X2010000700003&script=sci_arttext >. Accessed: May 20, 2015. doi: 10.1590/S0100-736X2010000700003.
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) and Rio Grande do Sul (PEDROSO et al., 2009PEDROSO, P.M.O. et al. Rhinopharyngeal mycotic rhinitis in a Texel sheep in Rio Grande do Sul. Acta Scientiae Veterinariae, v. 37, n. 2, p. 181-185, 2009. Available from: <Available from: http://www.ufrgs.br/actavet/37-2/art829.pdf >. Accessed: May 20, 2015.
http://www.ufrgs.br/actavet/37-2/art829....
). In Brazil the occurrence of conidiobolomycosis has ranged from 0.1 to 17.2% and the lethality rate always was 100% (SILVA et al., 2007aSILVA, S.M.M.S. Epidemiology and symptoms of conidiobolomycosis in sheep in the State of Piauí, Brazil. Pesquisa Veterinária Brasileira,v.27, n.4, p.184-190,2007a. Available from: <Available from: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-736X2007000400010 >. Accessed: May 20, 2015. doi: 10.1590/S0100-736X2007000400010.
http://www.scielo.br/scielo.php?script=s...
, b; MENDONÇA et al., 2012MENDONÇA, F.S. et al.Conidiobolomycosis in sheep in the state of Pernambuco. Revista Brasileira de Medicina Veterinária, v. 34, n. 3, p. 241-246, 2012. Available from: <Available from: http://www.rbmv.com.br/pdf_artigos/07-11-2012_10-42RBMV%20015.pdf >. Accessed: May 20, 2015.
http://www.rbmv.com.br/pdf_artigos/07-11...
).

Table 2 lists the ovine conidiobolomycosis outbreaks reported in Brazil, including the years 1979 to 2014. Epidemiological conditions that determined the occurrence of the disease in sheep in the country were generally associated with periods of high rates of rainfall, temperatures between 19ºC and 36°C, high relative humidity and increased decaying plant matter on the environment (SILVA et al., 2007aSILVA, S.M.M.S. Epidemiology and symptoms of conidiobolomycosis in sheep in the State of Piauí, Brazil. Pesquisa Veterinária Brasileira,v.27, n.4, p.184-190,2007a. Available from: <Available from: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-736X2007000400010 >. Accessed: May 20, 2015. doi: 10.1590/S0100-736X2007000400010.
http://www.scielo.br/scielo.php?script=s...
; BOABAID et al., 2008BOABAID, F. M. et al. Conidiobolomycosis in sheep in the state of Mato Grosso, Brazil. Pesquisa Veterinária Brasileira, v.28, n.1, p.777-781, 2008. Available from: <Available from: http://www.scielo.br/scielo.php?pid=S0100-736X2008000100012&script=sci_arttext >. Accessed: May 20, 2015. doi: 10.1590/S0100-736X2008000100012.
http://www.scielo.br/scielo.php?pid=S010...
; PEDROSO et al., 2009PEDROSO, P.M.O. et al. Rhinopharyngeal mycotic rhinitis in a Texel sheep in Rio Grande do Sul. Acta Scientiae Veterinariae, v. 37, n. 2, p. 181-185, 2009. Available from: <Available from: http://www.ufrgs.br/actavet/37-2/art829.pdf >. Accessed: May 20, 2015.
http://www.ufrgs.br/actavet/37-2/art829....
; FURLAN et al., 2010FURLAN, F. H. et al. Conidiobolomycosis caused by Conidiobolus lamprauges in sheep in the state of Santa Catarina, Brazil. Pesquisa Veterinária Brasileira,v.30, n.7, p.529-532,2010. Available from: <Available from: http://www.scielo.br/scielo.php?pid=S0100-736X2010000700003&script=sci_arttext >. Accessed: May 20, 2015. doi: 10.1590/S0100-736X2010000700003.
http://www.scielo.br/scielo.php?pid=S010...
; MENDONÇA et al., 2012MENDONÇA, F.S. et al.Conidiobolomycosis in sheep in the state of Pernambuco. Revista Brasileira de Medicina Veterinária, v. 34, n. 3, p. 241-246, 2012. Available from: <Available from: http://www.rbmv.com.br/pdf_artigos/07-11-2012_10-42RBMV%20015.pdf >. Accessed: May 20, 2015.
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). Such conditions favor the proliferation of the fungus and, consequently, increase environmental contamination and predispose susceptible animals to inhalation of conidia. In three outbreaks the animals were in Brachiaria spp. pastures (BOABAID et al., 2008; FURLAN et al., 2010; MENDONÇA et al., 2012MENDONÇA, F.S. et al.Conidiobolomycosis in sheep in the state of Pernambuco. Revista Brasileira de Medicina Veterinária, v. 34, n. 3, p. 241-246, 2012. Available from: <Available from: http://www.rbmv.com.br/pdf_artigos/07-11-2012_10-42RBMV%20015.pdf >. Accessed: May 20, 2015.
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). This type of vegetation might increase the fungus proliferation in the environment, since this vegetation produces considerable amount of organic matter being an ideal substrate for fungal growth. In all reports, the disease was observed in the period from December to June, coinciding with the hottest and humid periods in all regions where there were reports of sheep conidiobolomycosis (Table 2).

The main mode of infection involves inhalation, ingestion and dermal exposure to conidia of these fungi (DE PAULA et al., 2010DE PAULA, D. A. J. et al. Molecular characterization of ovine zygomycosis in central western Brazil. Journal of Veterinary Diagnostic Investigation, v. 22, n. 2, p. 274-277, 2010. Available from: <Available from: http://vdi.sagepub.com/content/22/2/274.long >. Accessed: May 20, 2015.
http://vdi.sagepub.com/content/22/2/274....
). The most common route of infection is by inhalation of conidia present in the grazing (HUMBER et al., 1989HUMBER, R. A. et al. Equine zygomycosis caused by Conidiobolus lamprauges. Journal of Clinical Microbiology, v. 27, n.3, p. 573-576, 1989. Available from: <Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC267365/ >. Accessed: May 20, 2015. doi:10.1080/01913120500482013.
http://www.ncbi.nlm.nih.gov/pmc/articles...
). These authors observed that the conidia might be ejected to a height of more than two centimeters from the soil. Thus, these conidia might reach the nasal mucosa. Another route of contamination might be due to injury caused by sharp plants contaminated with conidia (KETTERER et al., 1992KETTERER, P.J. et al. Rhinocerebral and nasal zygomycosis in sheep caused by Conidiobolus incongruus., Australian Veterinary Journal v. 69. n. 4, p. 85-87, 1992.). SILVA et al. (2007aSILVA, S.M.M.S. Epidemiology and symptoms of conidiobolomycosis in sheep in the State of Piauí, Brazil. Pesquisa Veterinária Brasileira,v.27, n.4, p.184-190,2007a. Available from: <Available from: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-736X2007000400010 >. Accessed: May 20, 2015. doi: 10.1590/S0100-736X2007000400010.
http://www.scielo.br/scielo.php?script=s...
) suggested that the prevalence of the disease in sheep might be related to the grazing habits of these animals favoring the inhalation of conidia.

Clinical manifestations

Ovine conidiobolomycosis is clinically manifested by the following forms: rhinofacial and nasopharyngeal (rhinopharyngeal) infection. The clinical course for both clinical forms varies from 1 to 5 weeks. The rhinofacial infection commonly affects the nasal vestibule, the mucocutaneous union of the nose, the upper lip, the skin of the muzzle, the proximal region of the face and the hard palate (SILVA et al., 2008a, b; RIET-CORREA et al., 2008RIET-CORREA, F. et al. Outbreaks of rhinofacial and rhinopharyngeal zygomycosis in sheep in Paraíba, northeastern Brazil. Pesquisa Veterinária Brasileira, v. 28, n. 1, p. 29-35, 2008. Available from: <Available from: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-736X2008000100005 >. Accessed: May 20, 2015. doi: 10.1590/S0100-736X2008000100005.
http://www.scielo.br/scielo.php?script=s...
). However, the animals affected by the nasopharyngeal form usually show apathy, progressive weight loss, serous to mucosa and/or bleeding nasal secretion, as well as breathing difficulty and fever. The involvement of the ethmoid region, nasal turbinates, paranasal sinuses, soft palate, orbit, pharyngeal muscles, and lymph nodes also have been described in this clinical form. The lesion may progress to the eye socket determining unilateral exophthalmia and several ocular injuries (RIET-CORREA et al., 2008PORTELA, R.A. et al. Diseases of the nasal cavity of ruminants in Brazil. Pesquisa Veterinária Brasileira,v. 30, n. 10, p. 844-854, 2010. Available from: <Available from: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-736X2010001000007 >. Accessed: May 20, 2015. doi:10.1590/S0100-736X2010001000007.
http://www.scielo.br/scielo.php?script=s...
; SILVA et al., 2007aSILVA, S.M.M.S. Epidemiology and symptoms of conidiobolomycosis in sheep in the State of Piauí, Brazil. Pesquisa Veterinária Brasileira,v.27, n.4, p.184-190,2007a. Available from: <Available from: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-736X2007000400010 >. Accessed: May 20, 2015. doi: 10.1590/S0100-736X2007000400010.
http://www.scielo.br/scielo.php?script=s...
,bSILVA, S.M.M.S. et al. Conidiobolomycosis in sheep in Brazil. Veterinary Pathology, v. 44, n. 3, p. 314-319, 2007b. Available from: <Available from: http://vet.sagepub.com/cgi/pmidlookup?view=long&pmid=17491072 >. Accessed: May 20, 2015.
http://vet.sagepub.com/cgi/pmidlookup?vi...
).

Table 2 shows that the predominant clinical presentation in sheep conidiobolomycosis outbreaks reported in Brazil was nasopharyngeal. It was also observed that in the described outbreaks, both clinical forms of the disease did not occur concurrently, except in a single outbreak (UBIALI et al., 2013UBIALI, D.G. et al. Pathology of nasal infection caused by Conidiobolus lamprauges and Pythium insidiosum in sheep. Journal of Comparative Pathology, v.149, n.2-3, p.137-145, 2013. Available from: <Available from: http://www.sciencedirect.com/science/article/pii/S0021997512004355 >. Accessed: May 20, 2015. doi: 10.1016/j.jcpa.2012.12.002.
http://www.sciencedirect.com/science/art...
). In these outbreaks, the main species identified were C. lamprauges andC. coronatus . According to UBIALI et al. (2013UBIALI, D.G. et al. Pathology of nasal infection caused by Conidiobolus lamprauges and Pythium insidiosum in sheep. Journal of Comparative Pathology, v.149, n.2-3, p.137-145, 2013. Available from: <Available from: http://www.sciencedirect.com/science/article/pii/S0021997512004355 >. Accessed: May 20, 2015. doi: 10.1016/j.jcpa.2012.12.002.
http://www.sciencedirect.com/science/art...
) infections caused by C. lamprauges were mainly related to nasopharyngeal form. Nevertheless, the same authors reported C. lamprauges in both clinical forms of sheep in Mato Grosso state.

The disease caused by C. incongruus is rare and has not been described in sheep in Brazil. However, this agent has medical importance (EL-SHABRAWI et al., 2014EL-SHABRAWI, M. H. F. et al. Entomophthoromycosis: a challenging emerging disease. Mycoses, v. 57, Suppl. 3, p.132-137, 2014. Available from: <Available from: http://onlinelibrary.wiley.com/doi/10.1111/myc.12248/epdf >. Accessed: Sept. 18, 2015.
http://onlinelibrary.wiley.com/doi/10.11...
) and it was reported in ovine in Australia (KETTERER et al., 1992KETTERER, P.J. et al. Rhinocerebral and nasal zygomycosis in sheep caused by Conidiobolus incongruus., Australian Veterinary Journal v. 69. n. 4, p. 85-87, 1992.; CARRIGAN et al., 1992CARRIGAN, M. J. et al. Ovine nasal zygomycosis caused by Conidiobolus incongruus. Australian Veterinary Journal, v. 69, n.10, p. 237-240, 1992. Available from: <Available from: http://www.ncbi.nlm.nih.gov/pubmed/1445069 >. Accessed: May 20, 2015.
http://www.ncbi.nlm.nih.gov/pubmed/14450...
) and in dogs in United States of America (MACKEY et al., 2015MACKEY, P.E. et al. Disseminated Conidiobolus incongruus in a dog: a case report and literature review. Medical Mycology Case Reports, v. 8, p. 24-28, 2015. Available from: <Available from: http://www.elsevier.com/locate/mmcr >. Accessed: Jun. 04, 2015. doi:10.1016/j.mmcr.2015.02.005.
http://www.elsevier.com/locate/mmcr...
).

Diagnosis

The definitive diagnosis of ovine conidiobolomycosis includes clinical and pathological findings associated with the mycological diagnosis involving the isolation and identification of the etiological agent.

Mycological diagnosis

The fungal growth on Sabouraud Dextrose Agar (SDA) or Potato Dextrose Agar (PDA) is usually evident after 5 days at 37°C and produces colonies that are wrinkled, white or pigmented (DE PAULA et al., 2010DE PAULA, D. A. J. et al. Molecular characterization of ovine zygomycosis in central western Brazil. Journal of Veterinary Diagnostic Investigation, v. 22, n. 2, p. 274-277, 2010. Available from: <Available from: http://vdi.sagepub.com/content/22/2/274.long >. Accessed: May 20, 2015.
http://vdi.sagepub.com/content/22/2/274....
). On SDA, the colonies at the beginning are flat, glabrous, waxy and cream color (DE PAULA et al., 2010DE PAULA, D. A. J. et al. Molecular characterization of ovine zygomycosis in central western Brazil. Journal of Veterinary Diagnostic Investigation, v. 22, n. 2, p. 274-277, 2010. Available from: <Available from: http://vdi.sagepub.com/content/22/2/274.long >. Accessed: May 20, 2015.
http://vdi.sagepub.com/content/22/2/274....
; VILELA et al., 2010VILELA, R. et al. Morphologic and phylogenetic characterization of Conidiobolus lamprauges recovered from infected sheep., Journal of Clinical Microbiology v. 48, n. 2, p. 427-432, 2010. Available from: <Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2815615/pdf/1589-09.pdf >. Accessed: May 20, 2015. doi: 10.1128/JCM.01589-09.
http://www.ncbi.nlm.nih.gov/pmc/articles...
), subsequently they became wrinkled and yellowed. On PDA, the colonies are thin, flat and smooth, with pleats in the center (VILELA et al., 2010VILELA, R. et al. Morphologic and phylogenetic characterization of Conidiobolus lamprauges recovered from infected sheep., Journal of Clinical Microbiology v. 48, n. 2, p. 427-432, 2010. Available from: <Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2815615/pdf/1589-09.pdf >. Accessed: May 20, 2015. doi: 10.1128/JCM.01589-09.
http://www.ncbi.nlm.nih.gov/pmc/articles...
). Microscopically, Conidiobolus spp. present large conidia (diameter 25 to 45μm), pyriform to spherical, born singly on unbranched conidiophores and expelled violently from these structures. In general, these conidia have basal buds (papillae) with rounded and prominent shape (SIDRIM & ROCHA et al., 2008SIDRIM, J.J.C.; ROCHA, M.F.G. Micologia médica a luz de autores contemporâneos. Rio de Janeiro. Guanabara Koogan. 408p, 2008. ).

Pathological diagnosis: macroscopic and microscopic aspects

Macroscopic aspects

In nasopharyngeal form of sheep conidiobolomycosis, macroscopically there is the proliferation of whitish or yellowish tissue, irregular, friable of granular consistency located in ethmoid and nasal septum. Frequently, the eye socket may be affected, causing craniofacial asymmetry and exophthalmia. In addition, an obstruction of the nasal meatus with retention of mucopurulent exudate in the frontal sinuses was observed. An irregular nodular proliferation obstructing the choanae, as well as infiltration of the cribriform plate and eye socket causing the protrusion of the eyeball were also reported. Lesions spread to the brain, lungs, lymph nodes, kidneys, heart, and gallbladder were noticed (SILVA et al., 2007bSILVA, S.M.M.S. et al. Conidiobolomycosis in sheep in Brazil. Veterinary Pathology, v. 44, n. 3, p. 314-319, 2007b. Available from: <Available from: http://vet.sagepub.com/cgi/pmidlookup?view=long&pmid=17491072 >. Accessed: May 20, 2015.
http://vet.sagepub.com/cgi/pmidlookup?vi...
; RIET-CORREA et al., 2008RIET-CORREA, F. et al. Outbreaks of rhinofacial and rhinopharyngeal zygomycosis in sheep in Paraíba, northeastern Brazil. Pesquisa Veterinária Brasileira, v. 28, n. 1, p. 29-35, 2008. Available from: <Available from: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-736X2008000100005 >. Accessed: May 20, 2015. doi: 10.1590/S0100-736X2008000100005.
http://www.scielo.br/scielo.php?script=s...
; BOABAID et al., 2008BOABAID, F. M. et al. Conidiobolomycosis in sheep in the state of Mato Grosso, Brazil. Pesquisa Veterinária Brasileira, v.28, n.1, p.777-781, 2008. Available from: <Available from: http://www.scielo.br/scielo.php?pid=S0100-736X2008000100012&script=sci_arttext >. Accessed: May 20, 2015. doi: 10.1590/S0100-736X2008000100012.
http://www.scielo.br/scielo.php?pid=S010...
; FURLAN et al., 2010FURLAN, F. H. et al. Conidiobolomycosis caused by Conidiobolus lamprauges in sheep in the state of Santa Catarina, Brazil. Pesquisa Veterinária Brasileira,v.30, n.7, p.529-532,2010. Available from: <Available from: http://www.scielo.br/scielo.php?pid=S0100-736X2010000700003&script=sci_arttext >. Accessed: May 20, 2015. doi: 10.1590/S0100-736X2010000700003.
http://www.scielo.br/scielo.php?pid=S010...
; MENDONÇA et al., 2012MENDONÇA, F.S. et al.Conidiobolomycosis in sheep in the state of Pernambuco. Revista Brasileira de Medicina Veterinária, v. 34, n. 3, p. 241-246, 2012. Available from: <Available from: http://www.rbmv.com.br/pdf_artigos/07-11-2012_10-42RBMV%20015.pdf >. Accessed: May 20, 2015.
http://www.rbmv.com.br/pdf_artigos/07-11...
).

RIET-CORREA et al. (2008RIET-CORREA, F. et al. Outbreaks of rhinofacial and rhinopharyngeal zygomycosis in sheep in Paraíba, northeastern Brazil. Pesquisa Veterinária Brasileira, v. 28, n. 1, p. 29-35, 2008. Available from: <Available from: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-736X2008000100005 >. Accessed: May 20, 2015. doi: 10.1590/S0100-736X2008000100005.
http://www.scielo.br/scielo.php?script=s...
) reported the rhinofacial infection of sheep conidiobolomycosis in the Brazilian state of Paraíba. In this form, gross lesions were characterized by the presence of dark brown ulcerated areas in the nasal mucosa, extending from mucocutaneous region into the nasal vestibule. The mucosa of the hard palate also showed a large ulcerated area, involving the gums and premolars. The cut surface of the nostrils and hard palate showed a brown or reddish spongy tissue with friable consistency. In this clinical form, lesions were not observed in other organs (e.g. the brain, lungs and lymph nodes) but they were reported in the nasopharyngeal form.

Microscopic aspects

On histopathological examination, the lesions of conidiobolomycosis sheep stained with hematoxylin-eosin were characterized by multifocal granulomas with a central necrosis area and eosinophilic granular appearance (RIET-CORREA et al., 2008RIET-CORREA, F. et al. Outbreaks of rhinofacial and rhinopharyngeal zygomycosis in sheep in Paraíba, northeastern Brazil. Pesquisa Veterinária Brasileira, v. 28, n. 1, p. 29-35, 2008. Available from: <Available from: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-736X2008000100005 >. Accessed: May 20, 2015. doi: 10.1590/S0100-736X2008000100005.
http://www.scielo.br/scielo.php?script=s...
). Inside the granulomas there were negatively stained structures representing the fungal hyphae surrounded by abundant Splendore-Hoeppli material. The necrotic areas were often surrounded by inflammatory cells, particularly eosinophils, neutrophils, mononuclear cells, multinucleated giant cells, and epithelioid macrophages (SILVA et al., 2007bSILVA, S.M.M.S. et al. Conidiobolomycosis in sheep in Brazil. Veterinary Pathology, v. 44, n. 3, p. 314-319, 2007b. Available from: <Available from: http://vet.sagepub.com/cgi/pmidlookup?view=long&pmid=17491072 >. Accessed: May 20, 2015.
http://vet.sagepub.com/cgi/pmidlookup?vi...
; BOABAID et al., 2008BOABAID, F. M. et al. Conidiobolomycosis in sheep in the state of Mato Grosso, Brazil. Pesquisa Veterinária Brasileira, v.28, n.1, p.777-781, 2008. Available from: <Available from: http://www.scielo.br/scielo.php?pid=S0100-736X2008000100012&script=sci_arttext >. Accessed: May 20, 2015. doi: 10.1590/S0100-736X2008000100012.
http://www.scielo.br/scielo.php?pid=S010...
; RIET-CORREA et al., 2008RIET-CORREA, F. et al. Outbreaks of rhinofacial and rhinopharyngeal zygomycosis in sheep in Paraíba, northeastern Brazil. Pesquisa Veterinária Brasileira, v. 28, n. 1, p. 29-35, 2008. Available from: <Available from: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-736X2008000100005 >. Accessed: May 20, 2015. doi: 10.1590/S0100-736X2008000100005.
http://www.scielo.br/scielo.php?script=s...
). Estructures as Hypha could be observed within giant cells (SILVA et al., 2007bSILVA, S.M.M.S. et al. Conidiobolomycosis in sheep in Brazil. Veterinary Pathology, v. 44, n. 3, p. 314-319, 2007b. Available from: <Available from: http://vet.sagepub.com/cgi/pmidlookup?view=long&pmid=17491072 >. Accessed: May 20, 2015.
http://vet.sagepub.com/cgi/pmidlookup?vi...
; MENDONÇA et al., 2012MENDONÇA, F.S. et al.Conidiobolomycosis in sheep in the state of Pernambuco. Revista Brasileira de Medicina Veterinária, v. 34, n. 3, p. 241-246, 2012. Available from: <Available from: http://www.rbmv.com.br/pdf_artigos/07-11-2012_10-42RBMV%20015.pdf >. Accessed: May 20, 2015.
http://www.rbmv.com.br/pdf_artigos/07-11...
). With Gomori's methenamine silver stain of these lesions, numerous thick hyphae were observed. These structures were rarely septate, irregular in shape, with black contoured wall, sometimes with bulbous dilatation in the extremities (SILVA et al., 2007bSILVA, S.M.M.S. et al. Conidiobolomycosis in sheep in Brazil. Veterinary Pathology, v. 44, n. 3, p. 314-319, 2007b. Available from: <Available from: http://vet.sagepub.com/cgi/pmidlookup?view=long&pmid=17491072 >. Accessed: May 20, 2015.
http://vet.sagepub.com/cgi/pmidlookup?vi...
; BOABAID et al., 2008BOABAID, F. M. et al. Conidiobolomycosis in sheep in the state of Mato Grosso, Brazil. Pesquisa Veterinária Brasileira, v.28, n.1, p.777-781, 2008. Available from: <Available from: http://www.scielo.br/scielo.php?pid=S0100-736X2008000100012&script=sci_arttext >. Accessed: May 20, 2015. doi: 10.1590/S0100-736X2008000100012.
http://www.scielo.br/scielo.php?pid=S010...
; RIET-CORREA et al., 2008RIET-CORREA, F. et al. Outbreaks of rhinofacial and rhinopharyngeal zygomycosis in sheep in Paraíba, northeastern Brazil. Pesquisa Veterinária Brasileira, v. 28, n. 1, p. 29-35, 2008. Available from: <Available from: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-736X2008000100005 >. Accessed: May 20, 2015. doi: 10.1590/S0100-736X2008000100005.
http://www.scielo.br/scielo.php?script=s...
; FURLAN et al., 2010FURLAN, F. H. et al. Conidiobolomycosis caused by Conidiobolus lamprauges in sheep in the state of Santa Catarina, Brazil. Pesquisa Veterinária Brasileira,v.30, n.7, p.529-532,2010. Available from: <Available from: http://www.scielo.br/scielo.php?pid=S0100-736X2010000700003&script=sci_arttext >. Accessed: May 20, 2015. doi: 10.1590/S0100-736X2010000700003.
http://www.scielo.br/scielo.php?pid=S010...
; MENDONÇA et al., 2012MENDONÇA, F.S. et al.Conidiobolomycosis in sheep in the state of Pernambuco. Revista Brasileira de Medicina Veterinária, v. 34, n. 3, p. 241-246, 2012. Available from: <Available from: http://www.rbmv.com.br/pdf_artigos/07-11-2012_10-42RBMV%20015.pdf >. Accessed: May 20, 2015.
http://www.rbmv.com.br/pdf_artigos/07-11...
).

According to DE PAULA et al. (2010DE PAULA, D. A. J. et al. Molecular characterization of ovine zygomycosis in central western Brazil. Journal of Veterinary Diagnostic Investigation, v. 22, n. 2, p. 274-277, 2010. Available from: <Available from: http://vdi.sagepub.com/content/22/2/274.long >. Accessed: May 20, 2015.
http://vdi.sagepub.com/content/22/2/274....
) the pathological aspects of conidiobolomycosis have been similar to other zygomycoses described, as well as pythiosis. All of these illnesses are characterized by the formation of granulomatous lesions and are difficult to treat. Consequently, it is necessary to conduct a careful differential diagnosis.

Serological and molecular diagnosis

UBIALI et al. (2013UBIALI, D.G. et al. Pathology of nasal infection caused by Conidiobolus lamprauges and Pythium insidiosum in sheep. Journal of Comparative Pathology, v.149, n.2-3, p.137-145, 2013. Available from: <Available from: http://www.sciencedirect.com/science/article/pii/S0021997512004355 >. Accessed: May 20, 2015. doi: 10.1016/j.jcpa.2012.12.002.
http://www.sciencedirect.com/science/art...
) utilized immunohistochemistry with polyclonal serum to perform a differential diagnosis of granulomatous rhinitis in sheep. Previously, SILVA et al. (2010) used this technique to confirm the fungal etiology of conidiobolomycosis in ovine. Several authors have suggested the use of molecular biology assays to search DNA sequences of conserved genes in fungal samples, including polymerase chain reaction (PCR) and DNA sequencing of intergenic regions (internal transcribed spacer, ITS) and ribosomal DNA units (18S, 5.8S and 28S rDNA) (DE PAULA et al., 2010DE PAULA, D. A. J. et al. Molecular characterization of ovine zygomycosis in central western Brazil. Journal of Veterinary Diagnostic Investigation, v. 22, n. 2, p. 274-277, 2010. Available from: <Available from: http://vdi.sagepub.com/content/22/2/274.long >. Accessed: May 20, 2015.
http://vdi.sagepub.com/content/22/2/274....
; BOTTON et al., 2011BOTTON, S. A. et al. Identification of Pythium insidiosum by nested PCR in cutaneous lesions of Brazilian horses and rabbits. Current Microbiology, v. 62, n. 4, p. 1225-1229, 2011. Available from: <Available from: http://link.springer.com/article/10.1007%2Fs00284-010-9781-4 >. Accessed: May 20, 2015. doi: 10.1007/s00284-010-9781-4.
http://link.springer.com/article/10.1007...
; SILVEIRA et al., 2013SILVEIRA, M. M. et al. Development and application of polymerase chain reaction test for detection of Conidiobolus lamprauges. Pesquisa Veterinária Brasileira,v.33, n.12, p.1448-1452, 2013. Available from: <Available from: http://www.scielo.br/scielo.php?pid=S0100-736X2013001200009&script=sci_arttext >. Accessed: May 20, 2015. doi: 10.1590/S0100-736X2013001200009.
http://www.scielo.br/scielo.php?pid=S010...
). DE PAULA et al. (2010DE PAULA, D. A. J. et al. Molecular characterization of ovine zygomycosis in central western Brazil. Journal of Veterinary Diagnostic Investigation, v. 22, n. 2, p. 274-277, 2010. Available from: <Available from: http://vdi.sagepub.com/content/22/2/274.long >. Accessed: May 20, 2015.
http://vdi.sagepub.com/content/22/2/274....
) and SILVEIRA et al. (2013SILVEIRA, M. M. et al. Development and application of polymerase chain reaction test for detection of Conidiobolus lamprauges. Pesquisa Veterinária Brasileira,v.33, n.12, p.1448-1452, 2013. Available from: <Available from: http://www.scielo.br/scielo.php?pid=S0100-736X2013001200009&script=sci_arttext >. Accessed: May 20, 2015. doi: 10.1590/S0100-736X2013001200009.
http://www.scielo.br/scielo.php?pid=S010...
) proposed the use of PCR to amplify the 18S rDNA region of pathogenicConidiobolus . SILVEIRA et al. (2013SILVEIRA, M. M. et al. Development and application of polymerase chain reaction test for detection of Conidiobolus lamprauges. Pesquisa Veterinária Brasileira,v.33, n.12, p.1448-1452, 2013. Available from: <Available from: http://www.scielo.br/scielo.php?pid=S0100-736X2013001200009&script=sci_arttext >. Accessed: May 20, 2015. doi: 10.1590/S0100-736X2013001200009.
http://www.scielo.br/scielo.php?pid=S010...
) confirmed the difficulty in identifying this microorganism in fungal culture, which was possible only in 26.6% from clinical samples. These authors also highlighted the importance of the use of molecular techniques for the definitive diagnosis of ovine conidiobolomycosis.

Differential diagnosis

For a long time, conidiobolomycosis in ovine was erroneously diagnosed as enzootic ethmoid tumor (SILVA et al., 2007aSILVA, S.M.M.S. Epidemiology and symptoms of conidiobolomycosis in sheep in the State of Piauí, Brazil. Pesquisa Veterinária Brasileira,v.27, n.4, p.184-190,2007a. Available from: <Available from: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-736X2007000400010 >. Accessed: May 20, 2015. doi: 10.1590/S0100-736X2007000400010.
http://www.scielo.br/scielo.php?script=s...
). However, the enzootic nasal tumor also known as enzootic nasal adenocarcinoma is a contagious chronic disease of goats and sheep, with viral etiology (retrovirus). Macroscopically, it is presented as unilateral or bilateral masses, pale, friable, located in the region of the ethmoid turbine and adjacent areas. Microscopically, the lesions may present features of adenomas to adenocarcinomas, usually classified as low malignancy adenocarcinoma (PORTELA et al., 2010PORTELA, R.A. et al. Diseases of the nasal cavity of ruminants in Brazil. Pesquisa Veterinária Brasileira,v. 30, n. 10, p. 844-854, 2010. Available from: <Available from: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-736X2010001000007 >. Accessed: May 20, 2015. doi:10.1590/S0100-736X2010001000007.
http://www.scielo.br/scielo.php?script=s...
).

Another relevant disease to be considered as differential diagnosis of conidiobolomycosis is pythiosis. In sheep, pathogenic Conidiobolus and Pythium insidiosum may be associated with rhinofacial rhinitis and nasopharyngeal infection; however, it is observed that conidiobolomycosis lesions in general are associated with the nasopharynx and these lesions have an aspect of a yellow or white firm mass (AGUIAR et al., 2014AGUIAR, G.M.N. et al. Epidemiological aspects of conidiobolomycosis in sheep in the Northeastern Brazilian semiarid region. Ciência Rural, v.44, n.12, p.2210-2216, 2014. Available from: <Available from: http://dx.doi.org/10.1590/0103-8478cr20131472 >. Accessed: June 30, 2015. doi: 10.1590/0103-8478cr20131472.
http://dx.doi.org/10.1590/0103-8478cr201...
). In contrast, pythiosis is associated with the rhinofacial region with production of necrotic and friable tissues (SANTURIO et al., 2008; UBIALI et al., 2013UBIALI, D.G. et al. Pathology of nasal infection caused by Conidiobolus lamprauges and Pythium insidiosum in sheep. Journal of Comparative Pathology, v.149, n.2-3, p.137-145, 2013. Available from: <Available from: http://www.sciencedirect.com/science/article/pii/S0021997512004355 >. Accessed: May 20, 2015. doi: 10.1016/j.jcpa.2012.12.002.
http://www.sciencedirect.com/science/art...
). Additionally, significant morphological differences are observed among the lesions caused by both microorganisms. Conidiobolomycosis shows an evident pattern of multifocal granulomatous lesion with wide hyphae (diameter of 7-30µm) surrounded by an abundant amount of Splendori-Hoeppli material. Again, in contrast, in pythiosis there is a marked caseous necrosis and thinner hyphae when compared to hyphae of pathogenic Conidiobolus , and surrounded by discrete Splendori-Hoeppli reaction (RIET-CORREA et al., 2008RIET-CORREA, F. et al. Outbreaks of rhinofacial and rhinopharyngeal zygomycosis in sheep in Paraíba, northeastern Brazil. Pesquisa Veterinária Brasileira, v. 28, n. 1, p. 29-35, 2008. Available from: <Available from: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-736X2008000100005 >. Accessed: May 20, 2015. doi: 10.1590/S0100-736X2008000100005.
http://www.scielo.br/scielo.php?script=s...
; PORTELLA et al., 2010PORTELA, R.A. et al. Diseases of the nasal cavity of ruminants in Brazil. Pesquisa Veterinária Brasileira,v. 30, n. 10, p. 844-854, 2010. Available from: <Available from: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-736X2010001000007 >. Accessed: May 20, 2015. doi:10.1590/S0100-736X2010001000007.
http://www.scielo.br/scielo.php?script=s...
; UBIALI et al., 2013UBIALI, D.G. et al. Pathology of nasal infection caused by Conidiobolus lamprauges and Pythium insidiosum in sheep. Journal of Comparative Pathology, v.149, n.2-3, p.137-145, 2013. Available from: <Available from: http://www.sciencedirect.com/science/article/pii/S0021997512004355 >. Accessed: May 20, 2015. doi: 10.1016/j.jcpa.2012.12.002.
http://www.sciencedirect.com/science/art...
).

Therapeutic approaches

The late diagnosis and the lack of a standard protocol of treatment for this fungal infection are factors that may contribute to the high lethality of Conidiobolus spp. infection (SILVA et al., 2007aSILVA, S.M.M.S. Epidemiology and symptoms of conidiobolomycosis in sheep in the State of Piauí, Brazil. Pesquisa Veterinária Brasileira,v.27, n.4, p.184-190,2007a. Available from: <Available from: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-736X2007000400010 >. Accessed: May 20, 2015. doi: 10.1590/S0100-736X2007000400010.
http://www.scielo.br/scielo.php?script=s...
). So far, no drug or chemical has been completely effective in the treatment of conidiobolomycosis (RIET-CORREA et al., 2008RIET-CORREA, F. et al. Outbreaks of rhinofacial and rhinopharyngeal zygomycosis in sheep in Paraíba, northeastern Brazil. Pesquisa Veterinária Brasileira, v. 28, n. 1, p. 29-35, 2008. Available from: <Available from: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-736X2008000100005 >. Accessed: May 20, 2015. doi: 10.1590/S0100-736X2008000100005.
http://www.scielo.br/scielo.php?script=s...
; KIMURA et al., 2011KIMURA, M. et al. Disseminated human conidiobolomycosis due to Conidiobolus lamprauges., Journal of Clinical Microbiology v.49, n.2, p.752-756, 2011. Available from: <Available from: http://jcm.asm.org/content/49/2/752.full >. Accessed: May 20, 2015. doi: 10.1128/JCM.01484-10.
http://jcm.asm.org/content/49/2/752.full...
; SILVA et al., 2012SILVA, J.A.G. et al. Thermoregulated genes differentially expressed in Conidiobolus lamprauges., Ciência Rural v.42, n. 9, p. 1610-1613, 2012. Available from: <Available from: http://www.scielo.br/scielo.php?pid=S0103-84782012000900015&script=sci_arttext >. Accessed: May 20, 2015. doi: 10.1590/S0103-84782012005000064.
http://www.scielo.br/scielo.php?pid=S010...
). VALLE et al. (2001VALLE, A. C. et al. Entomophthoramycosis by Conidiobolus coronatus. Revista do Instituto de Medicina Tropical de São Paulo, v. 43, n. 4, p. 233-236, 2001. ) proposed a combination of triazoles, itraconazole and fluconazole, in the treatment of rhinomycosis by C. coronatus in humans; however, there are no reports of any effective treatment in sheep. HAWKINS et al. (2006HAWKINS, E. C. et al. Treatment of Conidiobolussp. pneumonia with itraconazole in a dog receiving immunosuppressive therapy. Journal of Veterinary Internal Medicine, v.20, n.6, p.1479-1482, 2006. Available from: <Available from: http://onlinelibrary.wiley.com/doi/10.1111/j.1939-1676.2006.tb00769.x/abstract >. Accessed: May 20, 2015. doi: 10.1111/j.1939-1676.2006.tb00769.x.
http://onlinelibrary.wiley.com/doi/10.11...
) described a successful treatment with itraconazole employed in a dog with fungal pneumonia caused by a pathogenicConidiobolus . Later, TONDOLO et al. (2013TONDOLO, J.S. et al. In vitro susceptibility of Conidiobolus lamprauges recovered from sheep to antifungal agents. Veterinary Microbiology, v.166, n.3-4, p.690-693,2013. Available from: <Available from: http://www.sciencedirect.com/science/article/pii/S0378113513003866 >. Accessed: May 20, 2015. doi: 10.1016/j.vetmic.2013.07.024.
http://www.sciencedirect.com/science/art...
) performed in vitro susceptibility to the assay against isolates of C. lamprauges from sheep using amphotericin B, azoles, echinocandins, and terbinafine. These authors concluded that only terbinafine was active against this fungus and the microorganism demonstrated resistance or reduced susceptibility to the other antifungal drugs evaluated.

CONCLUSION

Ovine conidiobolomycosis is an endemic disease in Brazil, especially in the Northeast and Midwest regions, affecting predominantly the woolless sheep. The occurrence of the disease is related to climate conditions of these regions.C. coronatus andC. lamprauges are responsible for the sheep infections in Brazil.

Further information about the epidemiology of conidiobolomycosis, as well as the virulence factors and pathogenicity of the agent, is required in order to develop effective control and prevention measures of this important disease that affects sheep flocks in Brazil.

ACKNOWLEDGEMENTS

The authors thank for the financial support from Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) (Process 473162/2013-0). Additional acknowledgedments to Fundação de Amparo à Pesquisa do Estado do Rio Grande do Sul (FAPERGS) and Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES).

REFERENCES:

  • 1
    CR-2015-0935.R2

Publication Dates

  • Publication in this collection
    May 2016

History

  • Received
    27 June 2015
  • Accepted
    30 Oct 2015
  • Reviewed
    04 Mar 2016
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