New species of Eimeria (Apicomplexa: Eimeriidae) from the domesticated goat Capra hircus in New Zealand

Pulmonary and Gastrointestinal Parasitic Infections in Small Ruminant Autochthonous Breeds from Centre Region of Portugal-A Cross Sectional Study

The production of small ruminant autochthonous breeds in the Centre region of Portugal is practiced in a semi-extensive husbandry system, exposing animals to parasitic infections. The main objective of this study was to estimate the prevalence of lungworm infection and identify risk factors. Fecal samples of 203 goats and 208 sheep from 30 herds were collected per rectum and subjected to the modified Baermann test. The overall prevalence of infection was 57.7%, significantly higher in goats (95.6%) than in sheep (20.7%) (p < 0.001). According to the binary logistic regression model, sheep dewormed with albendazole, mebendazole plus closantel, or ivermectin plus clorsulon presented a risk of Protostrongylidae infection 29.702, 7.426, or 8.720 times higher, respectively, than those dewormed with eprinomectin. Additionally, the presence of gastrointestinal parasites was investigated in 307 fecal samples using Mini-FLOTAC®. The overall prevalence of infection was 86.3%, also significantly higher in goats (93.2%) than in sheep (79.9%) (p < 0.001). Strongyle-type eggs were the most frequently identified, both in sheep (69.8%) and goats (87.8%), followed by Eimeria oocysts (40.3% in sheep and 68.9% in goats). Considering the high prevalence and the burden of lungworm parasitic infection, it is urgent to determine its economic impact and the repercussions in animal health in the Centre region of Portugal to establish appropriate therapeutic guidelines.

Metaphylactic strategies using toltrazuril against coccidiosis in goat kids

Goat coccidiosis compromises animal welfare, reduces productivity and may cause mortality and delayed growth rates in goat kids around the weaning period worldwide. This field study was conducted to evaluate the efficacy of metaphylactic treatments with two doses of toltrazuril (20 or 40 mg/kg body weight - BW, p. o.), at different timing, in kids naturally infected with Eimeria spp. A total of 97 healthy goat kids (Majorera milk aptitude breed) were divided into five groups, depending on the age of treatment (2 or 7 weeks). One group remained untreated as a negative control until the end of the study. Faecal oocyst shedding, faecal consistency, and body weight of the animals were monitored at day 0 and at weekly intervals. Counts of oocysts per gram of faeces (OPG) were determined by a modified McMaster technique. Morphometric identification of Eimeria species was carried out on individual faecal samples from each experimental group after oocyst sporulation. Goat kids treated at two weeks of age maintained OPG values close to zero during the 5 weeks post-treatment and, overall, had lower faecal oocyst counts than untreated control animals. No significant differences were observed between the two doses of toltrazuril used in two-week-old treated animals. By contrast, when treatment was carried out at seven weeks of age, the dose of 40 mg/kg BW of toltrazuril reduced oocyst levels for longer and to a greater extent than the 20 mg/kg dose. Irrespectively of the treatment and dose, toltrazuril delayed the appearance of pathogenic Eimeria species, i. e. Eimeria ninakohlyakimovae and Eimeria arloingi. As a whole, Eimeria christenseni, with a rather moderate pathogenicity, was highly predominant throughout the study period, including the untreated control group, which was probably the reason why clinical signs of coccidiosis were barely observed throughout the experiment. Under these circumstances, the positive effect of toltrazuril on body weight condition observed in some treated groups was difficult to correlate to the timing and doses. Metaphylactic treatments with 20 mg/kg BW toltrazuril given at two weeks of age are sufficient to control oocyst excretion in goat kids; whereas if administered later in 7-week-old animals, thereby coinciding with the frequently observed peak of oocyst elimination in goat kids under field conditions, a higher dose might be advisable to prevent environmental contamination with infectious oocysts.

Immunoprotection against mixed Eimeria spp. infections in goat kids induced by X-irradiated oocysts

Strategies to control goat coccidiosis traditionally rely on the use of management practices combined with anticoccidial treatments, and limited effort has been made, so far, to address immunological control of caprine Eimeria infections. Previously, we showed that monospecific immunization with X-Rad-attenuated Eimeria ninakohlyakimovae oocysts induced considerable immunoprotection upon challenge. In the present study, we conducted a similar vaccination trial but using a mixture of caprine Eimeria species typically present in natural infected goats. For immunization, sporulated oocysts were attenuated by X irradiation (20 kilorad). All infections were performed orally applying 10⁵ sporulated oocysts of mixed Eimeria spp. per animal. In total, 18 goat kids were grouped as follows: (G1) immunized + challenge infected; (G2) primary + challenge infected; (G3) challenge infection control; and (G4) non-immunized/non-infected control. Overall, goat kids infected with attenuated oocysts (= immunized) shed less oocysts in the faeces and showed a lower degree of clinical coccidiosis than animals infected with non-attenuated oocysts. Animals of both challenge groups (G1 and G2) showed partial immunoprotection upon reinfection when compared to challenge infection control (G3). However, the degree of immunoprotection was less pronounced than recently reported for monospecific vaccination against Eimeria ninakohlyakimovae, most probably due to the complexity of the pathogenesis and related immune responses against mixed Eimeria spp. infections. Nevertheless, the data of the present study demonstrate that immunization with attenuated Eimeria spp. oocysts may be worth pursuing as a strategy to control goat coccidiosis.

Analysis of potential risk factors of caprine coccidiosis

Caprine coccidiosis represents a major concern in goat industry worldwide causing high economic losses, mainly due to poor weight gains, treatment costs and even death of kids. Therefore, analyses on risk factors involved in the establishment and outcome of this disease are important to improve infection status and herd management. In Portugal, approximately 400,000 goats are reared every year. The majority of them are allocated in the southern part of the country. In the current study, a representative number of animals (382 goats) and herds (37 herds) from Alentejo were monitored. Faecal samples from five young and five adult goats of each farm were collected rectally and examined individually by using the modified McMaster technique for oocyst counts (oocyst per gram of faeces - OPG). Additionally, a questionnaire on the husbandry conditions and anti-parasitic treatments was performed. Overall, a prevalence of Eimeria infections of 99% and 100% was detected on animal and herd level, respectively. Eimeria arloingi and E. ninakohlyakimovae as the two most pathogenic caprine species also constituted the most prevalent ones (34.91% and 29.90%, respectively), both in the young and the adult goat groups. As expected, OPG vales were significantly higher (p = 0.031) in young than in adult goats. Furthermore, risk factor analyses revealed young age, higher total number of animals on the farm and outdoor kidding as strongly associated with a higher risk of caprine coccidiosis. Overall, the high prevalence of pathogenic Eimeria species on Portuguese goat farms in combination with the occurrence of related risk factors strengthen the importance of coccidiosis control in caprine industry.

Gastrointestinal parasitism of goats in hilly region of Meghalaya, India

AIM

The aim of this study was to determine the prevalence of gastrointestinal (GI) parasitic infections in goats of hilly region of Meghalaya.

MATERIALS AND METHODS

A total of 834 fecal samples of goats were screened for 1 year (2014-2015) using flotation techniques.

RESULTS

The overall prevalence of GI parasitic infections in goats was 28.65%. Season-wise highest infections were recorded during rainy season (34.92%) followed by cool (26.87%), hot (26.62%), and cold (20.39%) seasons. Helminths and protozoa infections were recorded in 63.60% and 23.02% animals, respectively. Among the helminths, Strongyle spp. (32.63%) was recorded highest followed by Trichuris spp. (12.55%), Moniezia spp. (10.04%), and Trichuris spp. (8.36%). Among protozoa, only Eimeria spp. was detected. Seven different species of Eimeria spp. were identified, viz., Eimeria christenseni, Eimeria hirci, Eimeria caprina, Eimeria jolchijevi, Eimeria ninakohlyakimovae, Eimeria arloingi, and Eimeria kocharii for the first time from Meghalaya. Maximum egg per gram and oocyst per gram of feces were recorded in the month of August (932.4) and September (674.05), respectively. Mixed infections were recorded in 13.38% samples. Coproculture of goat fecal samples revealed the presence of Haemonchus contortus (72.16%), Oesophagostomum spp. (14.41%), Strongyloides spp. (8.91%), and Trichostrongylus spp. (4.50%) larvae.

CONCLUSION

This study indicates that GI helminths and protozoa infections are prevalent in goats of this hilly region of Meghalaya, throughout the year and highly prevalent during rainy season.

Far beyond Phagocytosis: Phagocyte-Derived Extracellular Traps Act Efficiently against Protozoan Parasites In Vitro and In Vivo

Professional mononuclear phagocytes such as polymorphonuclear neutrophils (PMN), monocytes, and macrophages are considered as the first line of defence against invasive pathogens. The formation of extracellular traps (ETs) by activated mononuclear phagocytes is meanwhile well accepted as an effector mechanism of the early host innate immune response acting against microbial infections. Recent investigations showed evidence that ETosis is a widely spread effector mechanism in vertebrates and invertebrates being utilized to entrap and kill bacteria, fungi, viruses, and protozoan parasites. ETs are released in response to intact protozoan parasites or to parasite-specific antigens in a controlled cell death process. Released ETs consist of nuclear DNA as backbone adorned with histones, antimicrobial peptides, and phagocyte-specific granular enzymes thereby producing a sticky extracellular matrix capable of entrapping and killing pathogens. This review summarizes recent data on protozoa-induced ETosis. Special attention will be given to molecular mechanisms of protozoa-induced ETosis and on its consequences for the parasites successful reproduction and life cycle accomplishment.

The apicomplexan parasite Eimeria arloingi induces caprine neutrophil extracellular traps

As a novel effector mechanism polymorphonuclear neutrophils (PMN) release neutrophil extracellular traps (NETs), which represent protein-labeled DNA matrices capable of extracellular trapping and killing of invasive pathogens. Here, we demonstrate for the first time NET formation performed by caprine PMN exposed to different stages (sporozoites and oocysts) of the goat apicomplexan protozoan parasite Eimeria arloingi. Scanning electron microscopy as well as fluorescence microscopy of sporozoites- and oocysts-PMN co-cultures revealed a fine network of DNA fibrils partially covering the parasites. Immunofluorescence analyses confirmed the co-localization of histones (H3), neutrophil elastase (NE), and myeloperoxidase (MPO) in extracellular traps released from caprine PMN. In addition, the enzymatic activity of NE was found significantly enhanced in sporozoite-exposed caprine PMN. The treatment of caprine NET structures with deoxyribonuclease (DNase) and the NADPH oxidase inhibitor diphenylene iodondium (DPI) significantly reduced NETosis confirming the classical characteristics of NETs. Caprine NETs efficiently trapped vital sporozoites of E. arloingi since 72% of these stages were immobilized-but not killed-in NET structures. As a consequence, early infection rates were significantly reduced when PMN-pre-exposed sporozoites were allowed to infect adequate host cells. These findings suggest that NETs may play an important role in the early innate host response to E. arloingi infection in goats.

Hematological and serum biochemical analyses in experimental caprine coccidiosis

In order to provide information on hematological and biochemical changes in Eimeria arloingi infection, eighteen newborn kids were allocated to three equal groups. Two groups, A and B were inoculated with a single dose of 1 × 10(3) and 1 × 10(5) sporulated oocysts of E. arloingi, respectively. The third group C remained uninfected as control. Blood samples were collected from jugular vein before inoculation as control and at 7, 14, 21, 28, 35 and 42 days post inoculation (DPI). Total erythrocyte and total leukocyte counts, hemoglobin (Hb), packed cell volume (PCV) and differential leukocyte counts were determined. Serum biochemical parameters including total protein (TP), albumin, chloride (Cl(-)), sodium (Na(+)), potassium (K(+)), aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), and gamma glutamyltransferase (GGT) were measured. All infected animals showed symptoms of clinical coccidiosis including diarrhea and oocyst excretion after the prepatent period that varied from 16 to 18 days after inoculation. The oocysts output did not stop until the end of the experiment. The diarrhea was associated with a reduction in ALP activity, increases in PCV and Hb and decreases in Na(+), Cl(-) and K(+). No significant differences were found in AST, ALT, GGT, albumin and TP during 42 DPI. There was no hepatic damage.

Isolation of an Eimeria ninakohlyakimovae field strain (Canary Islands) and analysis of its infection characteristics in goat kids

The current study was conducted to isolate a field strain of Eimeria ninakohlyakimovae, characterize its infectivity and the response to challenge under experimental conditions. The isolated strain (GC) induced a prepatent period of 14-15 days p.i., a patency of 7±2 days and a noticeable pathogenicity in infected goat kids. Challenge trials resulting in a decrease of oocysts per gram counts as well as a milder intensity of clinical signs in re-infected animals indicated the capacity of this strain to induce protective immune response. Altogether, the data reported in the present study suggest that the strain E. ninakohlyakimovae GC is a useful tool for the investigation of mechanisms of pathogenicity as well as host protective immune response in caprine coccidiosis, representing a valuable prerequisite for the development of future strategies in prophylaxis and control of this important parasitic disease in goat.

Antiparasitic efficacy of Artemisia absinthium, toltrazuril and amprolium against intestinal coccidiosis in goats

Various anti-protozoal dugs have been popularly used in the treatment of goat coccidiosis; however, residual effects are well noticed in host animals. The present study was undertaken with the objective to evaluate the anticoccidial efficacy of Artemisia absinthium, as a safe alternative in comparison to two conventional anticoccidial drugs (toltrazuril and amprolium) in goats (Capra hircus) naturally infected with Eimeria spp. (>5,000 oocyst per gram of faeces). Goat kids (1-3 month old, 10 kg body weight) were randomly allocated into five groups (eight kids each). Group A was negative for coccidiosis and was retained as uninfected and untreated (negative control). Group B was infected and was kept untreated (positive control). Group C was given a single oral dose of toltrazuril (Baycox 5 %) at 20 mg kg(-1) BW (IM). Group D received amprolium soluble powder 20 w/w% at 50 mg kg(-1) BW 5 days daily. Group E was given a single dose of ethanolic extract of Artemisia absinthium at 2 g kg(-1) BW. Clinical signs, body-weight gain (BWG) and number of oocysts per gram faeces (OPG) were monitored daily for 30 days post treatment (DPT). The OPG was highly reduced as early as 7 DPT and there was a marked improvement in body weight gain (7 DPT) and faster clinical recovery (3-6 DPT) in the toltrazuril treated kids compared to amprolium and Artemisia absinthium treated groups (P ≤ 0.05). In Artemisia absinthium treated kids, the oocysts continued to be in faeces up to 28th day post treatment indicating that ethanolic extract of herb was less efficacious against caprine coccidiosis as compared to amprolium and toltrazuril. From the observations of the present study it can be concluded that control of goat coccidiosis through single treatment of toltrazuril was highly effective as compared to the other two treatments. However, integrated control involving pasture management, chemical and herbal control will be a more realistic and sustainable means of controlling coccidiosis in goats. Further studies at different doses and concentrations using different solvent preparations of the plant extract are recommended to arrive at a certain conclusion about the anti-coccidial efficacy of Artemisia absinthium, which has been reported to be highly effective against other parasites in ruminants.

Influence of climatic and management factors on Eimeria infections in goats from semi-arid zones

A survey of Eimeria infections was performed in dairy goats and kids (<6 months old) of six farms from a dry desert area of Gran Canaria Island (Spain). The number of oocysts per gram of faeces (OPG) was determined by a modified McMaster technique over a total of 2,616 individual faecal samples taken from the rectum in monthly intervals. Eimeria oocysts were found in 96.1% of the samples with OPG ranging from 1 x 10(2) to 1.4 x 10(6). Kid goats had significantly (P < 0.001) higher OPG counts (46,496 +/- 5,228) than dairy females (2,225 +/- 287). Eight Eimeria species were identified, with Eimeria ninakohlyakimovae (30.0%), Eimeria arloingi (28.6%) and Eimeria alijevi (20.5%) being the most frequent species followed by Eimeria caprina (9.1%), Eimeria christenseni (4.5%), Eimeria jolchijevi (3.4%), Eimeria caprovina (3.2%) and Eimeria hirci (0.7%). Although significant differences were observed among goat groups and herds, the eight species were present in the six farms in both dairy goats and kids. The intensity of oocysts shedding was related to some factors such as the size of the herd and was further influenced by the prevailing climatic conditions of the area. The highest OPG counts were recorded during the hot season in dairy goats and close to weaning time in kids reared in small farms having no prophylactic treatments against eimeriosis.

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.