Description of a New Neospora Species (Protozoa: Apicomplexa: Sarcocystidae)

Abstract

Neospora hughesi n. sp. was isolated from the central nervous system tissue of an adult equine (Equus caballus) from California. The tachyzoites are crescent-shaped, approximately 2 x 5 microm (1.8-3.0 x 4.0-7.0 microm), with characteristic apical complex structures consisting of an anterior polar ring, conoid, numerous rhoptries filled with a uniform electron-dense material, and 22 microtubules extending posteriorly from the polar ring. Comparison of N. hughesi to canine and bovine Neospora caninum isolates showed phenotypic differences in immunoreactive proteins. Molecular analysis of the small subunit ribosomal RNA gene revealed no differences in the nucleotide sequence between N. hughesi and N. caninum isolates examined. However, the internal transcribed spacer I region revealed 7 nucleotide base differences between N. hughesi and N. caninum isolates (CN1 and BPA1) analyzed in this study. The existence of nucleotide base differences in the internal transcribed spacer regions suggests that this region may be a genetic marker for discriminating species within the genus Neospora. The ultrastructural, antigenic, and molecular data support distinction of N. hughesi as a new species, separate from N. caninum, the only recognized species in this genus.

Use of a serum-free medium to produce in vitro Neospora caninum and Toxoplasma gondii tachyzoites on Vero cells

“…However, two sero-epidemiological surveys performed in North America using the N. caninum Agglutination Test (NAT) or IFAT have demonstrated that 11.5 and 23.3% of horse sera regarded as positive respectively 160 F. De Meerschman et al [8,17]. Recently, N. hughesi was identified in the horse in California [31]. Since N. caninum cross reacts serologically with this new species [31], seroconversion is indicative of exposure to either of these two parasites.…”

“…Recently, N. hughesi was identified in the horse in California [31]. Since N. caninum cross reacts serologically with this new species [31], seroconversion is indicative of exposure to either of these two parasites. The use of horse serum could, therefore, also lead to unexpectedly high background values when performing IFAT or ELISA.…”

Occurrence of antibodies anti-Neospora spp. in cart horses and Crioula breed horses from Rio Grande do Sul state

“…caninum was firstly described in dogs in Norway (Bjerkas et al, 1984), from there on, it has been described in many warm-blooded species (Dubey and Lindsay, 1996). N. hughesi has been reported for the first time by Marsh et al (1998) who isolated a protozoan very similar to N. caninum (however, with structural and molecular differences) from brain and spinal marrow of a horse that was showing signs compatible with equine protozoal myeloencephalitis (EPM).The biological cycle of N. caninum was described by McAllister et al (1998) and involves definitive (DH) and intermediate (IH) hosts. The definitive ones are dogs and coyotes (McAllister et al, 1998;Gondim et al, 2004) and, besides sheltering the agent, they are Recebido em 16 de outubro de 2010 Aceito em 25 de fevereiro de 2011 E-mail: gugatoscan@hotmail.com characterized by excreting oocysts in their feces.…”

“…N. hughesi has been reported for the first time by Marsh et al (1998) who isolated a protozoan very similar to N. caninum (however, with structural and molecular differences) from brain and spinal marrow of a horse that was showing signs compatible with equine protozoal myeloencephalitis (EPM).…”

“…The biological cycle of N. caninum was described by McAllister et al (1998) and involves definitive (DH) and intermediate (IH) hosts. The definitive ones are dogs and coyotes (McAllister et al, 1998;Gondim et al, 2004) and, besides sheltering the agent, they are Recebido em 16 de outubro de 2010 Aceito em 25 de fevereiro de 2011 E-mail: gugatoscan@hotmail.com characterized by excreting oocysts in their feces.…”