Life cycle of Eimeria christenseni Levine, Ivens & Fritz, 1962 form the domestic goat, Capra hircus L

Morphological and molecular characterization of three Eimeria species from captured rangeland goats in Western Australia

Faecal shedding of Eimeria by captured rangeland goats (Capra hircus) was investigated using a longitudinal observational study. Faecal samples were collected from 125 male goats on four occasions. The first sampling occurred following capture and transport, immediately after arrival at a commercial goat depot (feedlot) in Western Australia, with subsequent 3 sample collections occurring at one month intervals thereafter. Goats were composite breed and aged approximately 9-12months on arrival at the feedlot. Prevalence and shedding intensity (faecal oocyst concentration) for Eimeria were determined using qPCR. Species were identified from individual oocysts (isolated using micromanipulation) using molecular analysis at two loci, specifically 18S rRNA and mitochondrial cytochrome oxidase gene (COI), and confirmed by microscopy. Longitudinal prevalence (animals positive at least once) for Eimeria spp. by qPCR was 90.4%, with 60% goats shedding Eimeria spp. on more than one occasion. Point prevalence (prevalence at a single sampling occasion) ranged from 2.4% (fourth sampling) to 70.4% (second sampling). Three species were identified at the 18S rRNA locus and confirmed by microscopy: E. christenseni (longitudinal prevalence for single infection 34.4%), E. hirci (17.6%) and E. arloingi (8.8%) over the four sample collections. Mixed infections were identified in 56.8% goats (longitudinal prevalence). 18S rRNA sequences from E. christenseni and E. hirci were 100% homologous with ovine E. ahsata and E. crandallis respectively, and E. arloingi was 100% similar to caprine E. arloingi. At the COI locus, E. christenseni, E. hirci and E. arloingi grouped separately, and were closely related to ovine E. ahsata, with genetic similarities of 96.5%, 92.6% and 91.4% respectively. This is the first report for molecular characteristics of caprine-derived Eimeria spp. using a combination of 18S rRNA and COI. Molecular techniques can be used to identify Eimeria spp. in goat faecal samples, specifically through characterization at 18S locus and other gene loci when used in parallel. Molecular techniques offer some advantages over microscopy for identification of Eimeria species, particularly with respect to precision.

Uso preventivo do toltrazuril para controle da coccidiose em cabritos de corte criados em região semiárida

<p>Objetivou-se com este estudo avaliar a eficácia do toltrazuril no controle da coccidiose em cabritos de corte criados extensivamente em região semiárida e determinar a idade mais adequada para realização do tratamento. Quarenta cabritos foram separados por faixa etária e tratados com toltrazuril em dose única aos 14; 21; 28 e 35 dias de idade. Amostras de fezes foram coletadas semanalmente para determinação do número de oocistos por grama de fezes (Oopg) nas semanas subsequentes ao tratamento. Os animais também foram pesados semanalmente para determinação do ganho de peso médio diário (GPD). Todos os cabritos tratados não apresentaram oocistos nas fezes pelo menos por uma semana após o tratamento. O Oopg dos cabritos tratados, independentemente da idade do tratamento, foi menor do que os não tratados (P<0,05) ao longo de 10 -11 semanas pós-tratamento. O ganho de peso médio diário (GPD) foi similar em todos os tratamentos avaliados. O Oopg não foi influenciado pelo sexo, mas sim pela idade ao tratamento. Os animais tratados aos 21 dias de idade não apresentaram oocistos nas fezes por um período maior que os demais. O tratamento com toltrazuril realizado aos 21 dias de idade foi eficaz para controle da coccidiose em cabritos criados extensivamente no semiárido.</p>

Enteric coccidiosis in the brown kiwi (Apteryx mantelli)

Enteric coccidiosis may cause significant morbidity and mortality in juvenile brown kiwi (Apteryx mantelli). Morphology of sporulated oocysts indicates that at least two Eimeria species are able to infect the brown kiwi. A histological study of the endogenous stages of coccidia was undertaken in the intestinal tracts of ten naturally infected young kiwi. Sequential sectioning of the entire intestinal tract allowed identification and recording of the distribution of the various coccidial life stages. Macromeronts measuring 268 × 162 μm when mature were found mainly within the lamina propria of the proximal one third of the small intestine. A smaller form of lamina propria meront was also identified (8.7 × 6.4 μm) with a similar distribution to the macromeronts. Small meronts (4.4 × 3.8 μm) were also identified in mucosal epithelial cells, with the overall peak in distribution within the intestinal tract being distal to the lamina propria meronts. Three morphologically distinctive gametocytes were identified. Type A gametocytes contained within epithelial cells shared the same distribution as the epithelial meronts. Polyps containing large numbers of type B gametocytes within the distal intestinal tract were found in two cases, and type C gametocytes were identified throughout the entire intestinal tract in one case only. The observational nature of this study precludes complete knowledge of the parasite life cycles using histology alone. However, it is likely that each of the three morphologically distinct gametocytes represents a separate species of enteric coccidia.

Endogenous development of Eimeria minasensis in experimentally infected goats

The endogenous development of Eimeria minasensis was studied in 9 coccidia-free goat kids inoculated with 10(5) sporulated oocysts/kg body weight. Kids were killed 4, 7 (2 animals), 10, 13, 16, 18, 19, and 22 days after inoculation (DAI). In tissue sections of the intestines stained with hematoxylin and eosin and examined by light microscopy, 2 generations of meronts, gamonts, gametes, and oocysts were found. The first generation of meronts developed in cells deep in the lamina propria of the jejunum and ileum. Mature giant meronts (299.4x243.8 microm) found 16 DAI were visible to the naked eye and contained a large number of crescent-shaped merozoites. The second generation of meronts developed in the epithelial cells of crypts of the ileum and above the host cell nuclei. Mature meronts (11.5x10.1 microm) with 18-28 comma-shaped merozoites were first seen 16 DAI. Gametogenesis took place in epithelial cells of the crypts and villi of the terminal part of the ileum, cecum, and colon. Macrogametes (27.8x17.6 microm), mature microgamonts (21.3x17.0 microm), microgametes, and oocysts (30.5x19.4 microm) were found 19 DAI. Sexual stages were below the host cell nucleus.

Eimeria minasensis n. sp. (Apicomplexa: Eimeriidae) in the domestic goat Capra hircus, from Brazil

Eimeria minasensis n. sp. is described in the domestic goat Capra hircus from Brazil. Oocysts ellipsoidal are 35 x 24.5 (32-37.7 x 20.9-27.9) microns. Sporocysts elongate-ellipsoid are 15.2 x 9 (12.3-18.4 x 7.8-10.2) microns, with a Stieda body at the narrow end. Oocyst wall smooth and bilayered; outer layer about 1.2 (0.8-1.6) microns and colorless; inner layer about 0.5 (0.4-0.8) micron and dark-brown. Micropyle, a mound-shaped micropylar cap 1.6 x 8.9 (0.8-2 x 7-10.2) easily dislodged; one or more oocyst polar granules present. Oocyst residuum absent. Sporocyst residuum present, composed of many scattered granules. Sporozoites elongate, lying lengthwise, "head to tail" in the sporocysts; one or two refractile globules are usually visible. Sporulation time was 120 hr at 27 degrees C, prepatent period, 19 to 20 days and patent period 15 to 25 days. Gamonts, gametes and oocysts present in cecum and colon. Prevalence was 12.8% (6/47) in goats from Minas Gerais, Brazil.

Coccidiosis in goats in the Czech Republic

An observational study was conducted to determine coccidial infections in goats of 13 farms in the Czech Republic. The prevalence of oocysts of Eimeria species in kids (less than 3 months old), weaned but not served goats (from 3 months to 1 year), and adult goats (1 year or more) was determined. Nine Eimeria species were identified in fecal samples by Sheather's sugar flotation technique. The overall prevalence of Eimeria oocysts in fecal specimens was 92.2%. Eimeria arloingi was the most common species with an overall prevalence of 84%, followed by E. hirci (63%) and E. ninakohlyakimovae (56%). Other species present were E. christenseni (55%), E. alijevi (36%), E. caprina (25%), E. aspheronica (12%), E. capriovina (6%) and E. jolchijevi (2%). Two or more Eimeria species were detected in 88% of the samples. The most prevalent species in kids was E. arloingi, while in weaned but not served and adult goats E. ninakohlyakimovae was the most frequently found. The number of oocysts excreted was generally lower in adult goats (2567.3+/-12678 OPG), whereas higher number oocyst per gram of feces (OPG) were found in kids (18565+/-24888 OPG). Clinical coccidiosis was detected in two farms, and E. arloingi and E. ninakohlyakimovae were implicated as its cause. Disease was observed in kids 2 to 4 weeks after weaning and watery feces with clumps of mucus, and color changes from brown to yellow or dark tarry, weight loss, and dehydration were the most conspicuous clinical signs. At necropsy, macroscopic changes included mucosal hemorrhages and whitish nodular polyps in the jejunum were found. Histopathological changes were characterized by local hypertrophy and hyperplasia of intestinal villi, villus blunting and inflammatory infiltration in the lamina propria. Numerous developmental stages of the parasites were observed in enterocytes and lacteals of intestinal villi.

Immunohistological demonstration of antigenicity of the various endogenous stages of Eimeria apsheronica in goats

Ten naive goat kids obtained soon after birth were reared coccidia-free in cages indoors. At one month of age they were each infected with 25,000 oocysts of E. apsheronica. Infection was monitored by examining the faeces for oocysts for two and a half weeks after patency. They were then euthanized and sections of their small intestines showing gross coccidal lesions were fixed for histology. Intestinal sections were incubated in pre-infection and post-infection sera to detect any antigen-antibody reactions using diaminobenzidine (DAB) as the stain. The sections treated with pre-infection sera stained very poorly in comparison to those treated with post-infection sera. The conclusion is drawn that serum antibodies which developed after infection reacted with the endogenous stages of the parasite and were histologically demonstrable.

Eimeria apsheronica in the goat: endogenous development and host cellular response

Most first generation schizonts of Eimeria apsheronica developed in the jejunum; others were distributed throughout the small intestine and occasionally in the caecum. Some were also found in the mesenteric lymph nodes, which were oedematous and haemorrhagic. In the intestine, haemorrhage and congestion were seen before parasites were detected, and continued throughout all later stages. Schizonts occurred in the lamina propria and occasionally in the submucosa, where they sometimes caused a cellular inflammatory response. Schizonts were first seen at 8 days post-infection (DPI); they had poorly defined nuclei and were enclosed in a capsule-like wall. At 16 DPI, many had matured, had a mean size of 125 x 82 microns, and were filled with numerous spindle-shaped merozoites, which were in ranks and loops. At 18 and 20 DPI, when small white lesions (1-3 mm in diameter) were observed in the jejunum and elsewhere in the small intestine, a second generation of schizonts, macrogametes, microgametocytes and maturing oocysts were seen, in the epithelial cells of the small intestine and caecum. Their mean sizes, respectively, were: 26.2 x 18.9, 24.7 x 18.5, 30.2 x 21.7 and 26.6 x 19.3 microns. Macrogametes contained basophilic central and eosinophilic peripheral granules. The sexual stages were associated with a generalized cellular inflammatory response.

Extraintestinal stages of Eimeria bovis in calves and attempts to induce relapse of clinical disease

Monoclonal antibodies to all life cycle stages of Eimeria bovis were used in an avidin-biotin immunoperoxidase test to examine extraintestinal tissues from experimentally infected calves for developmental stages of the parasite. First-generation meronts of Eimeria bovis were found in the mesenteric lymph nodes (MLNs) of three of four calves examined during the first 18 days of primary experimental infection. No extraintestinal stages were found in the MLNs of two calves examined 69 days after a primary infection or in five calves examined 6 months after a challenge infection. Tissue homogenates of liver, spleen, and MLNs from immune calves were not infectious for nonimmune recipient calves following oral or intraperitoneal inoculation indicating that infectious stages were not present in these extraintestinal tissues at the time of inoculations. Relapse of clinical coccidiosis and reoccurrence of oocyst shedding were not seen in E. bovis immune calves that were stressed by being put on a 16-week corticosteroid treatment program.

Experimental infections with coccidiosis and serum antibody quantitation in two breeds of goats

Two goat breeds, Anglonubian and Saanen were obtained at an early age and reared coccidia-free until they were 1 month old. They were then infected with 200,000 sporulated oocysts comprising mainly Eimeria christenseni (49%), E. apsheronica (29%) and lesser proportions of E. arloingi, E. hirci, E. ninakohlyakimovae and E. alijevi. Following patency, the number of faecal oocysts per gram were determined for each animal and body weights taken weekly. An ELISA was developed to assay antibody titres in pre- and post-infection sera of each individual kid. Cleaned unsporulated oocysts were sonified and the resulting soluble antigen used. Anglonubians shed significantly more oocysts daily (P less than 0.01) and also suffered greater retardation in growth. Initially both breeds had very similar growth rates, however post-infection weekly body weight gain among the Anglonubians was on average 1100 g compared to 1300 g for the Saanens. Antibody titres post-infection increased significantly among the Saanens (P less than 0.01) and also all but one among the Anglonubians recorded an increase in antibody titres. Unsuckled kid serum was devoid of any antibody activity.