Prevalence of bovine fascioliasis in a new-emerging focus of human fascioliasis in BoyerAhmad district,southwest of Iran

BackgroundThe prevalence of fascioliasis in a population of cattle in a new-emerging focus of human fascioliasis in Boyer-Ahmad District, in the southwest of Iran, was investigated, using an ELISA system and coprological methods.MethodsBlood, as well as stool samples, were collected from 150 dairy cattle consisted of 82 (54.7%) males and 68 (45.3%) females, aged from 1 to 8 years, selected from different pastures. The stool samples were evaluated by direct wet mount microscopic examination as well as sedimentation methods. Moreover, modified Telemann was used for detecting of Fasciola eggs. Anti-Fasciola antibodies in the cattle sera samples were determined, using a Fasciola excretory-secretory antigen-specific ELISA.ResultsAnti-Fasciola antibodies were detected in 64 (42.4%) of the subjects by ELISA. Out of 64 seropositive cases, 29 (45.3%) were female and 35 (54.6%) were male. No significant association was found between sex and seropositivity to fascioliasis. Considering the age of the cattle, the highest prevalence of fascioliasis (23%) was found in the 5-year old age group. However, the difference between the age of the cattle and seropositivity to fascioliasis was not statistically significant (P > 0.05). Fasciola eggs were not detected in fecal samples of any of the studied cattle, while Paramphistomide, as well as Dicrocoelium dendriticum eggs, were detected in 6 (4%) and 17 (11.3%) of the subjects, respectively.ConclusionFindings of the current study provide basic information about bovine fascioliasis in a new focus of human fascioliasis in Iran, which is needed for effective control of this parasitic infection in such areas.     

A comparison of the infectivity of Trichuris suis ova embryonated by four different methods

Four methods for embryonating the eggs of Trichuris suis in the laboratory were compared. Eggs were mixed with moist vermiculite (method 1) or were suspended in a 0.2% potassium dichromate solution that was either aerated (2), non-aerated (3) or deoxygenated (4). It was shown that differences in the method of culture profoundly affected the ability of the fully developed eggs to hatch and the parasites to become established in pigs. Of the four methods compared, ova of highest infectivity were produced after culture in moist vermiculite.     

Egg quality and lipid composition of eggs from hens fed Camelina sativa

The present study was conducted to investigate the effect of feeding Camelina sativa to layer birds on egg production, egg quality characteristics, egg lipids, and fatty acid and lipid oxidation products. Fifty-eight-week-old ISA Brown Leghorn laying hens (n = 48) were kept in individual cages and were fed a corn- and soybean meal-based diet with added Camelina meal at 0%, (control), 5%, (CAM5), 10% (CAM10), and 15% (CAM15). The experimental diets were fed for a period of 80 d. Hen-day egg production was lowest for CAM15 (P < 0.05). A significant reduction in yolk weight was observed for CAM10 and CAM15 eggs when compared with control eggs (P < 0.05). Yolk weight, as a percentage of egg weight, was lower for CAM10 and CAM15 eggs, whereas albumen weight, as a percentage of egg weight, was higher in CAM10 and CAM15 eggs than in control eggs (P < 0.05). The yolk:albumen ratio was higher in control eggs than in CAM10 and CAM15 eggs (P < 0.05). Egg total fat content was lowest for CAM15 eggs and was 31.5, 31.9, 30.8, and 29.5 for control, CAM5, CAM10, and CAM15 eggs, respectively (P < 0.05). Total n-3 fatty acids constituted 0.32% in control eggs compared with 2.54, 2.69, and 2.99% in CAM5, CAM10, and CAM15 eggs (P < 0.05). An 8-fold increase in docosahexaenoic acid was observed in CAM15 eggs when compared with control eggs (P < 0.05). The n-6:n-3 ratio was 14.8, 5.6, 4.6, and 4.3 for control, CAM5, CAM10, and CAM15 eggs, respectively (P < 0.05). Total saturated fats were lowest for CAM5 and CAM10 eggs. Eggs from the CAM15 regimen had higher TBA-reactive substance values (P < 0.05) than those from the CAM5, CAM10, or control regimen. Camelina meal could be incorporated into poultry rations as a source of energy, protein, and essential n-3 and n-6 fatty acids. However, inclusion of more than 10% Camelina meal in the hen diet may affect egg lipid quality aspects. Therefore, measures for minimizing lipid peroxidation should be used to enhance egg quality and lipid stability.     

Influence of Early Season Moxidectin Treatments on Acquisition of Immunity to Ostertagia ostertagi in Calves

Moxidectin, a newly developed endectocide, has previously been demonstrated to have a high efficacy against gastrointestinal nematodes in cattle (Ranjan et al. 1992, Scholl et al. 1992). In a field trial (Yang, Satrija and Nansen, unpublished data) matched groups of 8 first-season Black Pied Friesian heifer calves, 6-8 months of age, were turned out in early May 1992 on a permanent pasture contaminated with trichostrongyles. The groups were grazed separately on comparable plots until they were housed in mid October 1992. Group Β was treated with moxidectin at turnout, and group C was treated at turnout and again 8 weeks after turnout. A third group served as non-treated controls (group A). The results showed that the 2 early season prophylactic treatments (group C) reduced the late season herbage trichostrongyle larval infectivity with 80 to 90%, whereas the reduction accomplished by only 1 treatment at turnout (group B) was much less. Group C excreted significantly lower numbers of strongyle eggs than groups A and B. The non-treated controls showed clinical signs of trichostrongylosis in late September, which coincided with a steep rise in serum pepsinogen levels reaching an average peak level of 3.5 IU tyrosine litre-1. A few animals in group Β showed softening of faeces particularly in the very late season. In contrast, animals receiving 2 moxidectin treatments remained in a clinically good condition throughout the season.     

Natural trematode infestation in feral Nebrodi Black pigs: Pathological investigations

Few studies describe the parasites of pigs bred in the wild state, although pigs are a known reservoir of trematode infestation. This article reports the results of a retrospective study carried out from January 2003 to June 2007 on 3021 Nebrodi Black male and female pigs, regularly slaughtered, aged between 8 months and 4 years. Fasciola hepatica and Dicrocoelium dendriticum flukes were detected in 143 (4.37%) of 3021 livers. The predominant histological features were multifocal to diffuse chronic hepatitis, with fibrosis and severely thickened walls of the bile ducts and chronic parietal, sometimes nodular inflammation. F. hepatica infestation was frequently associated with marked hyperplasia and hypertrophy of the submucosal glands. The study results confirm the important role swine play in the transmission of trematode infestations, indicate the prevalence of these parasites in the Nebrodi Park area, and draw attention to the need for a prophylaxis plan to prevent the spread of infestation to ruminants and humans living in the area.     

A Preliminary Study of the Biological Control of Strongyles Affecting Equids in a Zoological Park

The main goal in this research was to determine the beneficial effect of incorporating biological procedures in parasite control programs for equids in zoological parks. Two trials were developed for Equus quagga, E asinus , and E africanus asinus. The first trial (September 2010 to August 2011) consisted of chemotherapy only (ivermectin plus praziquantel), and the second trial (September 2011 to September 2012) consisted of administration of chemotherapy and chlamydospores of the nematophagous fungus Arthrobotrys (Duddingtonia) flagrans. The effect of these measures was evaluated by the estimation of the reduction in the fecal egg counts (FECR). In the first trial, 100% FECR values were achieved 15 days after treatment in all the animals. The egg reappearance period (ERP) was 2-3 months for the equids, and all of them were passing strongyle eggs in the feces at 2-4 months after their deworming. In the second experiment, the FECR values were 100% in the three species. ERPs of 3 months in the European donkeys, 4 months in the Africans, and 6 months in the zebras were recorded. All the equids had positive results for the coprological flotation test 4-8 months after anthelmintic administration. This preliminary study demonstrates the incorporation of chlamydospores of nematophagous fungus, as A flagrans appears highly promising for reduction of the infective stages of the strongyles affecting captive animals, but the experimental design precludes true determination of whether the treatment is fully efficacious.     

METHOD OF SEMEN COLLECTION AND ARTIFICIAL INSEMINATION IN SNAKES

This study focuses on the method for sperm extraction and artificial insemination in snakes. Ten adult healthy snakes (4.6) were included in the study (Pantherophis guttatus 1.3; Hydrodynastes gigas 1.1; Corallus hortulanus 1.1; and Sanzinia madagascariesis 1.1). Massage of the ventral aspect of the caudal third of the male snake body for 2 to 3 minutes was performed successfully for the semen collection. Both female and male P. guttatus and H. gigas were placed in brumation, with the female snakes being assessed for ovarian activity after emerging from dormancy. Only females showing ultrasonographic evidence of vitellogenic follicles were included in the study. S. madagascariensis and C. hortulanus were maintained at the same temperature through the year, and the ovarian activity was assessed ultrasonographically prior to artificially inseminating the animal. With the aid of a rigid endoscope, fresh semen was delivered through the cloaca and into the females’ oviducts using a catheter connected to the syringe. The technique failed in female S. madagascariensis and H. gigas. Two female P. guttatus laid eggs 2 months after artificial insemination, with hatchlings emerging following 2 months of development within the eggs. The third female corn snake did not lay an egg. The female C. hortulans produced eggs 4 months after insemination. The manual massage method of sperm collection in male snakes and endoscopy-assisted insemination in female snakes may be useful for conservation programs.     

Survival and retention of infectivity of the mitePsoroptes ovis off the host

Psoroptes ovis mites were removed from infected sheep and placed in positions where wool and mites normally accumulate during sheep scab outbreaks. The ambient temperature and humidity were monitored over a 3-week period and the survival and infectivity times were examined. The procedure was carried out during each of the seasons. The hatchability of mite eggs was also examined. It was found that little variation occurred between seasons, with mites regularly retaining viability and infectivity for 15 days during all seasons. Mites that survived for more than 16 days failed to infect sheep. Mite eggs retained hatchability for up to 7 days.     

Cestodes and trematodes of wild sheep,Ovis ammon orientalis,and goitered gazelle,Gazella subgutturosa,in Iran

Two hundred and fifty wild sheep, Ovis ammon orientalis, and sixty five gazelles, Gazella subguttorosa, from different National Parks and Protected Regions of Iran, were shot and examined for the presence of metazoan parasites. Among the parasites recovered, Moniezia benedeni, Helicometra giardi, Cysticercus tenuicollis, Fasciola SPP. and Dicrocoelium dendriticum were absent in gazelle, whereas the other parasites were seen in both species of animals examined.Five adult tapeworms (Moniezia expansa, M. benedeni, Helicometra giardi, Stilesia globipunctata, and Avitellina centripunctata), three larval cestodes (Hydatid cyst, Cysticerucus tenuicollis and C. ovis) and three trematodes (Fasciola hepatica, F. gigantica and Dicrocoelium dendriticum) were found in the infected animals.     

Strongyle infections of small ruminants in Nigeria

A survey of strongyle infections was conducted in sheep and goats reared in a traditional e extensive husbandry system in two ecological zones if Nigeria. One zone had a seasonal pattern of infection. The majority of animals had faecal worm parasite egg counts of below 500 eggs per gram. Kids, and lambs younger than 3 months did not carry strongyle worm burdens, and the highest infection rate was found in the 7–12 month age group. A high proportion of small ruminants shed strongyle eggs during the postparturient period.The helminth species found by the use of larval culture techniques on the faeces were: Haemonchus contortus, Trichostrongylus colubriformis and Oesophagostonum columbianum. Adults of the same species were found in the few animals necropsied. The significance of the findings is discussed.     

Recovery threshold of Toxocara canis eggs from soil

The purpose of this study was to evaluate the threshold of Toxocara canis eggs form soil samples through utilisation of a centrifuge-flotation technique (CFT). Aliquots of soil (1 g each) were artificially contaminated with known numbers of T. canis eggs (1, 10, 25, 50, 100, and 200 eggs). The threshold was evaluated based on a CFT using zinc sulphate (Zn₂SO₄) and sodium nitrate (Na₂NO₃) solutions at a specific gravity of 1.20. The number of eggs recovered was directly proportional to the number of eggs employed to seed the soil. Both solutions enabled full recovery of samples containing merely three eggs; only Zn₂SO₄ demonstrated efficiency in soil contaminated with a single egg. A recovery rate of 100% was obtained for all tests with samples containing 10 and 25 eggs for Zn₂SO₄ and Na₂NO₃, respectively_. There was no difference in the mean number of recovered eggs regarding either the efficacy of the solutions or the repetition of evaluations in the same trial (p > 0.05). Therefore, the CFT is efficient for the detection of Toxocara eggs, even in samples containing low egg numbers.     

A study on the survival of Taenia saginata eggs on soil in Denmark

The infectivity of Taenia saginata eggs exposed to environmental conditions on a natural soil surface in Denmark was studied by feeding the eggs to susceptible calves, followed by determination of the number of cysts developed. The results indicated that a small proportion of the eggs remained infective for 6 1/2 months, but not for 9 1/2 months when deposited in May 1986, and for 5 1/2 months but not for 8 1/2 months when deposited in September 1987. Viability of eggs was tested in vitro and compared with infectivity obtained in calves.     

Selenium contents of eggs from broiler breeders supplemented with sodium selenite or zinc-l-selenium-methionine

This study evaluated the effects of sources and levels of Se in broiler breeder diets on egg production and Se concentration in eggs. Fifty Cobb 500 hens, 22 wk of age, were individually placed in steel cages and fed a basal diet without Se supplementation for 3 wk. Birds were then provided 5 dietary treatments with 10 replicates of 1 individual hen, which had dietary Se supplied from sodium selenite (inorganic; Na₂ SeO₃, 45% Se) or from Zn-l-Se-methionine (organic; ZnSeMet, 0.1% Se) as follows: treatment 1, 0.15% Se from Na₂ SeO₃; treatment 2, 0.30% Se from Na₂ SeO₃; treatment 3, 0.15% Se from ZnSeMet; treatment 4, 0.30% Se from ZnSeMet; treatment 5, 0.15% Se from Na₂ SeO₃ + 0.15% Se from ZnSeMet. Evaluations were conducted in 2 periods of 4 wk each. Experimental diets were prepared through the supplementation of corn-soybean meal diets. Egg production and egg weight were recorded daily, whereas specific gravity was measured twice a week from 25 to 32 wk. In the first period, the hens fed 0.30 ppm of organic Se produced more eggs (P < 0.05), whereas no difference (P > 0.05) in egg production was found in the second period. Period evaluations showed that egg weight was not different (P > 0.05), whereas specific gravity decreased (P < 0.05) and Se concentration in eggs increased (P < 0.05) in the second period, regardless of Se source. A comparison between treatments with single Se sources demonstrated that the concentration of Se in eggs followed the increased levels in the feeds when ZnSeMet was used (P < 0.05). However, the supplementation of a combination of sources (Na₂ SeO₃ and ZnSeMet) produced similar egg Se concentrations.     

Isoenzyme patterns of phosphateses and esterases in Fasciola hepatica and Dicrocoelium dendriticum

A study was made of alkaline and acid phosphatase isoenzymes and non-specific esterases in homogenates of the trematodes Fasciola hepatica and Dicrocoelium dendriticum obtained from infected tissues of Capra hircus and Ovis aries using horizontal polyacrylamide gel electrophoresis.The esterase patterns in F. hepatica and D. dendriticum were different. Homogenate of F. hepaticafrom both hosts gave four enzyme bands. For D. dendriticum, however, while homogenates of parasites from C. hircus also gave four bands, those of O. aries gave only three bands.Acid and alkaline phosphatases in homogenates of both parasites showed three enzyme bands, but there was a host species difference betwen the enzyme patterns of specimens collected from C. hircus versus O. aries.     

Pilot project to investigate over-wintering of free-living gastrointestinal nematode larvae of sheep in Ontario,Canada

This study investigated the overwintering survival and infectivity of free-living gastrointestinal nematode (GIN) stages on pasture. The presence of GIN larvae was assessed on 3 sheep farms in Ontario with a reported history of clinical haemonchosis, by collecting monthly pasture samples over the winter months of 2009/2010. The infectivity of GIN larvae on spring pastures was evaluated using 16 tracer lambs. Air and soil temperature and moisture were recorded hourly. Free-living stages of Trichostrongylus spp. and Nematodirus spp. were isolated from herbage samples. Gastrointestinal nematodes were recovered from all tracer lambs on all farms; Teladorsagia sp. was the predominant species. Very low levels of Haemonchus contortus were recovered from 1 animal on 1 farm. The results suggest that Haemonchus larvae do not survive well on pasture, while Teladorsagia sp., Trichostrongylus spp. and Nematodirus spp. are able to overwinter on pasture in Ontario and are still infective for sheep in the spring.     

Comparative analysis of destruction of the infective forms of Trichuris trichiura and Haemonchus contortus by nematophagous fungi Pochonia chlamydosporia; Duddingtonia flagrans and Monacrosporium thaumasium by scanning electron microscopy

The present study aimed to demonstrate by scanning electron microscopy (SEM) the in vitro predatory activity of nematophagous fungi Pochonia chlamydosporia (VC1 and VC4 isolates) Duddingtonia flagrans (AC001 isolate) and Monacrosporium thaumasium (NF34a isolate) on eggs of Trichuris trichiura and infective larvae (L3) of Haemonchus contortus. The work was divided into two experimental tests (A and B). In tests A and B, the predatory activity of nematophagous fungi P. chlamydosporia, D. flagrans and M. thaumasium on eggs of T. trichiura and H. contortus L3 was observed. After 6 h, in test A, isolates P. chlamydosporia (VC1 and VC4) had a role in destroying eggs of T. trichiura. For fungi D. flagrans and M. thaumasium the ovicidal activity on T. trichiura eggs was not observed. Test B showed that D. flagrans (AC001) and M. thaumasium (NF34a) were capable of predating H. contortus L3, but no predation by the fungus P. chlamydosporia was seen. These fungi can offer potential for the biological control of nematodes.     

Serological survey of Encephalitozoon cuniculi in farm rabbits in Italy

Rabbit sera (n = 1600) from 40 commercial farms were submitted to a serological screening for Encephalitozoon cuniculi by an enzyme-linked immunosorbent assay (ELISA) and a carbon immunoassay (CIA test). Antibodies anti-Encephalitozoon cuniculi were found in 505/1600 (31.6%) sera analysed, and all the farms (100%) resulted positive. Rabbits older than 4 months showed a significantly higher seropositivity for E. cuniculi (chi-squared test: p < 0.0001) than rabbits under 4 months, E. cuniculi sero-prevalence showed an increasing trend in rabbits within the farm along with the increase in the “number of rabbits on the farm”; however, this trend was not significant (Spearman’s correlation: p = 0.073).The findings of the present study confirm that rabbit is the main reservoir of E. cuniculi; they are of epidemiological relevance and immediate public health importance because of the recognized infectivity in humans by the microsporidium.     

Do stocking rate and a simple run management practice influence the infection of laying hens with gastrointestinal helminths?

The aim of this experiment conducted at four sites in Switzerland was to investigate the transmission and infectivity of the two main helminth parasite species of poultry (Ascaridia galli and Heterakis gallinarum) in outdoor runs with two different stocking rates. Additionally, the influence of a simple management practice (mowing of run) on helminth transmission was studied. Three run types were created on each site: runs C served as control (stocking rate 10 m²/hen, no management), runs B corresponded to runs C but were managed (10 m²/hen, management). In runs A stocking rates were doubled compared to control runs (5 m²/hen, no management). During two subsequent layer flocks, a set of parasitological parameters (faecal egg counts (FECs), prevalence, worm burdens in hens and in tracer animals, helminth eggs in soil) as well as parameters describing the run vegetation were determined. The increased stocking rate (runs A) led to a larger proportion of bare soil and to a reduction of the average vegetation height. In runs with a lower stocking rate (B and C), the proportion of bare soil did not increase during the experimental period. Irrespective of the run type, numbers of helminth eggs in the soil decreased significantly with an increasing distance to the hen houses, while the percentage of ground coverage as well as vegetation height increased. However, across runs the correlation between the percentage of ground cover and the values of eggs per gram soil between runs was very low (r² = 0.0007, P = 0.95) indicating a non-causal relationship. Significant differences in FEC were found in flock 2 (P < 0.001): FEC of hens in managed runs B were 24% lower (P < 0.05) than those of the control animals. Although not significant, the corresponding prevalence was lower (−9.7%) in hens from managed runs as well. Hens from runs with a high stocking rate (A) had significantly higher FEC than hens from control runs (C). In flock 2 management (n.s.) and higher stocking rates (−62%, P < 0.05) decreased the worm burdens. Tracer animals from runs with a high stocking rate (A) had significantly higher FEC than tracers from runs B and C in two tracer series. This was not reflected in the worm burdens. Overall, the stocking rate of hens in the outdoor run seemed not to influence the transmission patterns of A. galli and H. gallinarum and repeated mowing of runs did not reduce helminth infections. Lower stocking rates, however, led to a substantial improvement of the run vegetation.     

New multiplex PCR method for the simultaneous diagnosis of the three known species of equine tapeworm

Although several techniques exist for the detection of equine tapeworms in serum and feces, the differential diagnosis of tapeworm infection is usually based on postmortem findings and the morphological identification of eggs in feces. In this study, a multiplex polymerase chain reaction (PCR)-based method for the simultaneuos detection of Anoplocephala magna, Anoplocephala perfoliata and Anoplocephaloides mamillana has been developed and validated. The method simultaneously amplifies hypervariable SSUrRNA gene regions in the three tapeworm species in a single reaction using three pairs of primers, which exclusively amplify the internal transcribed spacer 2 (ITS-2) in each target gene. The method was tested on three types of sample: (a) 1/10, 1/100, 1/500, 1/1000, 1/2000 and 1/5000 dilutions of 70 ng of genomic DNA of the three tapeworm species, (b) DNA extracted from negative aliquots of sediments of negative control fecal samples spiked with 500, 200, 100, 50 and 10 eggs (only for A. magna and A. perfoliata; no A. mamillana eggs available) and (c) DNA extracted from 80, 50, 40, 30, 10 and 1 egg per 2 μl of PCR reaction mix (only for A. magna and A. perfoliata; no A. mamillana eggs available). No amplification was observed against the DNA of Gasterophilus intestinalis, Parascaris equorum and Strongylus vulgaris. The multiplex PCR method emerged as specific for the three tapeworms and was able to identify as few as 50 eggs per fecal sample and as little as 0.7 ng of control genomic DNA obtained from the three species. The method proposed is able to differentiate infections caused by the two most frequent species A. magna or A. perfoliata when the eggs are present in feces and is also able to detect mixed infections by the three cestode species.     

An investigation for seasonal trends in bovine leukemia virus infection

Monthly incidence rates for the detection of bovine leukemia virus (BLV) infection were calculated for a 15-month period for cattle over 12 months of age in a 200-cow dairy herd. Detection of BLV infection was based on the presence of persisting antibodies as measured by agar-gel immunodiffusion using the glycoprotein-51 antigen. A non-parametric procedure was used to examine 6-month trends in cumulative monthly incidence rates. Over the 15-month study, 25 heifers were detected as becoming infected with BLV after 12 months of age. No differences were found between the 12 monthly incidence rates (p = 0.77). Cumulative incidence rates between June and September (the fly season) were not higher than those for any other 6-month period (p = 0.29). Similarly, there was no evidence that BLV infection was transmitted during artificial insemination (p = 0.18) or during routine vaccination procedures (p = 1.0). Cumulative rates for a period corresponding to exposure of heifers to the dry herd were excessively high (p = 0.01). These findings suggest that transmission of BLV infection in the cattle studied was associated with close physical contact between susceptible and infected cattle, and not with biting flies, artificial insemination, or vaccination procedures.