Echinococcus Granulosus In Dogs Research Articles

Protective efficacy of six recombinant proteins as vaccine candidates against Echinococcus granulosus in dogs.

Cystic echinococcosis (CE) is caused by the infection of Echinococcus granulosus sensu lato (E. granulosus s.l.), one of the most harmful zoonotic helminths worldwide. Infected dogs are the major source of CE transmission. While praziquantel-based deworming is a main measure employed to control dog infections, its efficacy is at times compromised by the persistent high rate of dog re-infection and the copious discharge of E. granulosus eggs into the environment. Therefore, the dog vaccine is a welcome development, as it offers a substantial reduction in the biomass of E. granulosus. This study aimed to use previous insights into E. granulosus functional genes to further assess the protective efficacy of six recombinant proteins in dogs using a two-time injection vaccination strategy. We expressed and combined recombinant E. granulosus triosephosphate isomerase (rEgTIM) with annexin B3 (rEgANXB3), adenylate kinase 1 (rEgADK1) with Echinococcus protoscolex calcium binding protein 1 (rEgEPC1), and fatty acid-binding protein (rEgFABP) with paramyosin (rEgA31). Beagle dogs received two subcutaneous vaccinations mixed with Quil-A adjuvant, and subsequently orally challenged with protoscoleces two weeks after booster vaccination. All dogs were sacrificed for counting and measuring E. granulosus tapeworms at 28 days post-infection, and the level of serum IgG was detected by ELISA. Dogs vaccinated with rEgTIM&rEgANXB3, rEgADK1&rEgEPC1, and rEgFABP-EgA31 protein groups exhibited significant protectiveness, with a worm reduction rate of 71%, 57%, and 67%, respectively, compared to the control group (P < 0.05). Additionally, the vaccinated groups exhibited an inhibition of worm growth, as evidenced by a reduction in body length and width (P < 0.05). Furthermore, the level of IgG in the vaccinated dogs was significantly higher than that of the control dogs (P < 0.05). These verified candidates may be promising vaccines for the prevention of E. granulosus infection in dogs following two injections. The rEgTIM&rEgANXB3 co-administrated vaccine underscored the potential for the highest protective efficacy and superior protection stability for controlling E. granulosus infections in dogs.

Determination of copro-prevalence of Echinococcus granulosus and associated factors in domestic dogs: a household cross-sectional study in Huancarama, Peru

Echinococcosis is an important disease with regard to public health and the leading role that humans have in fulfilling the transmission cycle. The objective of this study was to determine the copro-prevalence of Echinococcus granulosus in dogs from homes in Huancarama, Peru, and the factors associated with this infection. The research was basic, prospective, quantitative, observational, cross-sectional, and analytical. This study was approved by the Institutional Ethics Committee for the Use of Animals (CIEA) and the Institutional Research Ethics Committee (CIEI) of the Universidad Peruana Cayetano Heredia. The sample comprised of 519 homes. A geographic information system (GIS) was used to develop layers of information on the study area with georeferencing of the locations of these homes. Information processing was performed using Excel for Windows 2010, Statistical Package for the Social Sciences SPSS 25 software, and ArcGIS 10.8. Univariate and multivariate logistic regression tests were performed to determine the possible associations. Categorical variables were statistically contrasted using the chi-square test with 95% confidence intervals and P ? 0.05, which indicated the extreme degree of significance. It was found that 94.4% of the houses had dogs and that the prevalence of E. granulosus was 27.7% (95/343; 95% CI 22.8-32.6). The distance from the house to the cattle slaughterhouse was associated with disease occurrence (P &lt; 0.01). Locations in the Suni altitude zone presented a higher prevalence (41.8%) (P &lt; 0.05). Lack of knowledge that humans can contract echinococcosis was associated with disease occurrence (P &lt; 0.05).

Biological potential cestodes of Echinococcus granulosus in dogs and sheep in the Republic Dagestan

The article is devoted to the study of the biotic potential and the role of the cestode Echinococcus granulosus in the infection of shepherd dogs and sheep in the republic. It has been established that the average intensity of invasion (II) of the causative agent of echinococcosis in shepherd dogs in the surveyed areas (Kizlyarsky, Laksky, Nogaysky, Sergokalinsky, Suleiman – Stalsky, Khasavyurt, Tsumadinsky, Shamilsky, etc.) is 1768 ± 245; 2924 ± 369; 3456 ± 382; 4683 ± 597; 2249 ± 321; 1870 ± 263; 2633 ± 352; 2149 ± 286 specimens / specimen. Infection of adult sheep with echinococcosis occurs in all surveyed areas, with fluctuations in the intensity of invasion (II) from 14.8 ± 1.3 to 21.3 ± 1.9 specimens / specimen, on average 17.56 ± 1.53 specimens. /individual. In sheep of all age groups, with a complete helminthological autopsy, in 1 ml of echinococcal fluid, fertile larvocysts were found in an amount of 20.36 ± 1.15 specimens / individual, except for young sheep, up to 1 year old. In sheep under the age of 2 years, fertile larvocysts of Echinococcus granulosus are found in the amount of 9.2 ± 0.41 specimens / specimen 0.83 ± 0.076 thousand specimens. The average number of fertile larvocysts found in 1 ml of fluid in sheep at the age of up to 3 years is 15.8 ± 0.93 specimens / individual and 1.15 ± 0.098 thousand specimens; up to 4 years old – 20.5 ± 1.17 specimens / individual and 1.92 ± 0.17 thousand specimens; up to 5 years – 27.3 ± 1.69 specimens / individual and 2.58 ± 0.26 thousand specimens; up to 6 years old – 36.7 ± 1.88 specimens / individual and 3.06 ± 0.49 thousand specimens. These data indicate an increase in the role and activity of the ovine variant of the causative agent of echinococcosis Echinococcus granulosus.

OBTENCIÓN DE echinococcus GRANULOSUS EN CANINOS INFECTADOS EXPERIMENTALMENTE CON PROTOESCÓLICES DE QUISTES HIDATÍDICOS.

The objective of the present study was to experimentally reproduce the biological cycle of Echinococcus granulosus in dogs. Twelve dogs, 4-50 months old, were infected with 80,000-308,000 protoscolices recovered from lung and liver hidatyd cysts in sheep reared in the central highlands of Peru. Dogs were slaughtered 28-39 days post infection (p.i) and the small intestine was divided in three equal portions (anterior, medium, and posterior) and parasites were counted. The location of parasites in the three portions of intestine was recorded in three dogs. Eight out of 12 dogs resulted positive to the infection and the number of parasites varied from 1,299 till 65,000 per dog. Animals slaughtered on the 28th p.i day resulted negative. The preferred site for parasites was the medium portion of the small intestine. It was shown that the oral inoculation of protoscolices from sheep hydatic cysts was effective to reproduce the biological cycle of the E. granulosus in dogs.

Effect of immunization with protoscolices antigens of hydatid cysts on growth of Echinococcus granulosus in dogs

The study was designed to evaluate the immune response of puppies, injected by different protein fractions extracted from protoscolieces, obtained from ovine hydatid cyst. Indirect heamagglutination revealed a remarkable increase in the antibody titers for the immunized groups (A1.5, A3, B1.5, and B3) before and after challenge when compared with the control. Biological variations showed decline in numbers of adult Echinococcus granulosus in the immunized groups when compared with the control. Other variations proved dropping in numbers of the worms within the same immunized groups. Subsequent reductions of cestodes were reported which were 83.8%, 81.3%, 78.2% and 74.6% for the groups A3, A1.5, B3, and B1.5, respectively.

Modelling the transmission of Echinococcus granulosus in dogs in the northwest and in the southwest of Morocco

Echinococcus granulosus ( E. granulosus) infection was studied in 151 dogs in two regions of Morocco: 68 dogs in the northwest (Loukkos) and 83 dogs in the southwest (Tiznit). The mean prevalence rates of echinococcosis in dogs were 58.82% (46.23–70.63%) in Loukkos and 55.42% (44.10–66.34%) in Tiznit and the mean abundances of E. granulosus per dog were 75 (59–93) and 547 (504–595), respectively. The mean abundance of E. granulosus in dogs was fitted to a negative binomial distribution by the maximum likelihood techniques to define parameters. E. granulosus was aggregated in dogs in the two regions. The prevalence of infection and the abundance of E. granulosus in dogs were fitted to mathematical models in order to determine if the parasite population is partly regulated by definitive host immunity. The best fit was obtained with the models assuming the presence of immunity. The mean time of exposure to infection was similar in the two regions and ranged from 8 months to about 2 years. The infection pressures (number of E. granulosus) obtained per dog each year were 65 (8–294) in Loukkos and 476 (316–886) in Tiznit. The proportion of dogs susceptible to infection was still high along the life of the dogs in Loukkos, while it was not different from zero in old dogs of Tiznit.

Screening for Echinococcus granulosus in dogs: Comparison between arecoline purgation, coproELISA and coproPCR with necropsy in pre-patent infections

Echinococcus granulosus is an important zoonotic infection of dogs. The purpose of the present study assessed the performance of two laboratory diagnostic methods with arecoline purgation and necropsy in infected dogs. In total 65 dogs were successfully experimentally infected with protoscoleces of E. granulosus from ovine infection. At 14–34 days post-infection groups of dogs were purged with arecoline hydrobromide and then necropsied. Faecal samples were tested at weekly intervals by coproantigen ELISA and coproPCR. The necropsy infection rate with E. granulosus was 89.2%. Only 43% of dogs were successfully purged after one arecoline dose; this percentage increased to 76.9% for two doses of arecoline purgation. E. granulosus coproantigen was detected by coproELISA in 82.8% of faeces. The positive and negative predictive values for coproantigen ELISA were 96 and 44.4% respectively. E. granulosus DNA was detected in pre-patent faecal samples by coproPCR in 25.9% of dogs. These results indicate that coproELISA is more sensitive than arecoline purgation for the detection of pre-patent E. granulosus infection in dogs. CoproPCR detected E. granulosus DNA in dog faeces by 21 days post-infection before egg production.

Patent and pre-patent detection of Echinococcus granulosus genotypes in the definitive host

The detection of Echinococcus granulosus in dogs is important for epidemiological surveillance and evaluation of cystic hydatic disease control programs. We report the efficacy of two PCR-based methods to detect patent and pre-patent infection in dogs experimentally infected with E. granulosus. The detection is based on amplification of a fragment of a mitochondrial gene (Mit-PCR) and a DNA repetitive element (Rep-PCR) of E. granulosus. We tested the ability of both methods to detect several genotypes of the parasite. Both PCR methods could detect E. granulosus in pre-patent and patent periods, even when microscopical observation of eggs resulted negative in fecal samples. The Mit-PCR produced the same amplification pattern for all the parasite genotypes tested while the amplification patterns with the Rep-PCR differed among groups of strains. Fecal samples collected from dogs of an endemic area were diagnosed with more sensitivity than arecoline hydrobromide purgation. These molecular methods could be applied in the confirmation of coproantigen-positive fecal samples and to verify the success of control programs.

Epidemiological evaluations of the efficacy of slow-released praziquantel-medicated bars for dogs in the prevention and control of cystic echinococcosis in man and animals

To assess the epidemiological efficacy of type SRP III slow-released praziquantel-medicated bars for dogs in the prevention and control of cystic echinococcosis in man and livestock, praziquantel-medicated bars were implanted subcutaneously in over 90% of dogs in villages in north Xinjiang, China, where cystic echinococcosis is highly endemic. After implantation, infection rate of Echinococcus granulosus in dogs, specific antibodies in children and prevalence of echinococcosis in one-year-old lambs were observed for 3 years. Coproantigen of E. granulosus was positive in 41.2% of the dogs at the start of experiment. In the second and third year after medicated-bar implantation, coproantigen was undetectable in any dogs examined, while 3.0% of dogs were positive at the end of the fourth year. The antibody positive rate in 7-year-old pupils, that was 41.2% before the experiment, declined gradually and it was 5.4% in the fourth year, while children in the non-intervention control area showed 30.6% seropositivity. The prevalence of hydatid disease in children aged 7–16 years also declined significantly. The prevalence of hydatidosis in lambs one year of age was 44.8% in the first year, dropping to 10.7% in the fourth year, while in the non-intervention control area the level of infection was 46.4%. These results demonstrated not only that the slow released praziquantel-medicated bars efficiently blocked reinfection in dogs at least for 2 years, but also the measure was effective in preventing transmission of cystic echinococcosis to both man and livestock.

The Effect Of Environmental Temperature In The Growth And Development Of Echinococcus granulosus (Batsch1786

The study highligthened on the effect of the field enviromental &amp; controlledtempratures in the experimental infection with Echinococcus granulosus indogs, n = 6 local dogs, at the age of 1.5-3 months, were used . Each dog wasdosed with 8658 protoscoleces with 92.78% viability for 28 and 33 days postinfection (PI). Animals were subdivided into 2groups. Results denoted that thelow enviromental temperatures retarded the growth and development of E.granulosus.All tapeworms, isolated from the small intestine of dogs housedunder controlled temperatures, with the average of 21.85ºc(group1),had 3proglottids,whereas those isolated from dogs housed under field temperatures,with the average of 11.12ºc (group2) ,had only 2 proglottids.The average totallength of E. granulosus ,at the age of 28 days, isolated fromgroup1,was1.70±0.24mm,longer than those that isolated from group2,with theaverage length of 1.13±0.06mm.The average total length of E.granulosus ,at theage of 33 days , isolated from group 1 and 2 ,was 2.68±0.35 mm and 1.67±0.21,respectively . Significant statistical differences (p&lt;0.05) were found in theaverage total length of E.granulosus isolated from both groups at different ages.Echinococcus granulosus isolated from group1 were found mature more thanthose isolated from group2,and the number of rostellar hooks of the former werealso more than those of the 2nd group, the number of rostellar hooks were, at theage of 33 days,were34.53±2.19 and29.47±0.62 for the 1st and 2nd gr

Preliminary study of the presence of antibodies against excretory-secretory antigens from protoscoleces of Echinococcus granulosus in dogs with intestinal echinococcosis

The aim of the present study was to analyze the antibody response against excretory-secretory antigens (ES-Ag) from Echinococcus granulosus protoscoleces, using sera from dogs infected with E. granulosus and other helminths. ES-Ag were obtained from the first 50 h maintenance of protoscoleces in vitro. Immunochemical characterization was performed by immunoblotting with sera from dogs naturally infected with E. granulosus (n = 12), sera from dogs infected with helminths other than E. granulosus (n = 30), and helminth-free dog sera (n = 20). These findings were compared to those obtained from a somatic extract of protoscoleces (S-Ag). ES-Ag only showed four cross-reacting proteins of 65, 61, 54, and 45-46 kDa. Antigens with apparent masses of 89 and 50 kDa in ES-Ag and of 130 and 67 kDa in S-Ag were identified by sera of dogs infected with E. granulosus only, whereas a protein of 41-43 kDa was recognised by the majority of the sera from dogs with non-echinococcal infection. Employing ELISA to study the same sera, S-Ag revealed higher immunoreactivity than ES-Ag, but also showed higher cross-reactivity levels when sera from dogs with non-echinococcal infection were assayed in immunoblotting.

Does the presence of Spirometra erinacei reduce the efficacy of praziquantel against Echinococcus granulosus in dogs?

Does the presence of Spirometra erinacei reduce the efficacy of praziquantel against Echinococcus granulosus in dogs?

Effect of Host Sex and Litter on the Population Dynamics of Echinococcus granulosus in Dogs

Twenty-one Beagle dogs consisting of 10 males and 11 females and belonging to 3 litters were infected with 60,000 E. granulosus protoscolices each. They were killed on day 40, the parasites from their intestines recovered, and the number of worms, average number of proglottides per worm, average length per worm, percentage of worms with a uterine cavity, and percentage of egg-bearing worms were determined for each dog and analyzed per sex and litter. On average, the dogs had 1,253 +/- 339 worms (means +/- standard error) with 2.42 +/- 0.1 proglottides, were 1.59 +/- 0.07 mm long, and 25.6 +/- 4.8% of the worms presented a uterine cavity and 1.2 +/- 0.6% bore eggs. The number of worms exhibited a bimodal distribution with 19 dogs having less than or equal to 2,565 worms and 2 greater than or equal to 5,520 worms. Average number of proglottides also showed a bimodal distribution with 7 dogs having less than or equal to 2.1 proglottides per worm and 14 dogs having greater than or equal to 2.4 proglottides per worm. The parasites were significantly more numerous in females than in the males (1,964 +/- 573 vs. 681 +/- 202), had more proglottides (2.67 +/- 0.08 vs. 2.15 +/- 0.16), and were longer (1.72 +/- 0.07 vs. 1.44 +/- 0.11 mm). The percentages of parasites with a uterine cavity (27.8 +/- 5.9 vs. 23.2 +/- 8.1) or bearing eggs (1.0 +/- 0.5 vs. 1.5 +/- 1.8) were comparable in females and males.(ABSTRACT TRUNCATED AT 250 WORDS)

Cestode infections in animals : immunological diagnosis and vaccination

Cestode infections in animals are important because several species are zoonotic, causing cysticercosis and hydatidosis in man, and because of the economic losses incurred due to infections in livestock. Information on immunological diagnosis of and vaccination against cestode infection is restricted almost exclusively to the taeniid cestodes in which two groups of mammalian hosts are concerned: the intermediate host infected with the larval parasite and the definitive host infected with the adult tapeworm parasite. Research towards developing serological tests for the diagnosis of larval cestode infection in animals has been largely unsuccessful. Substantial problems remain, due to the frequent existence of multiple infections with different taeniid species and antigenic crossreactivity between these related parasites, and the low level of specific antibody response to infection. Problems with poor specificity and sensitivity of traditional serological tests for cysticercosis and hydatidosis have prevented the development of any practical test for ante-mortem diagnosis of infection. A recent new approach to the diagnosis of Taenia saginata infection by detecting circulating parasite antigen offers some prospect for the development of a practical diagnostic test for cysticercosis in cattle. The effectiveness of the arecoline purge for detection of Echinococcus granulosus in dogs has been reduced by the widespread availability of praziquantel. A serological method for diagnosis of E. granulosus in dogs has been developed which offers equivalent or superior diagnostic sensitivity compared with arecoline purge. This test should provide a valuable tool in hydatid control campaigns for the diagnosis of existing or recent past infections in dogs. Substantial progress has been made towards developing a practical vaccine for the prevention of T. ovis infection in sheep. An antigen derived from the parasite egg has been identified and produced in Escherichia coli using recombinant DNA techniques. The vaccine, which protects sheep against challenge infection with T. ovis, is the first highly effective defined antigen vaccine against any parasite infection of man or animals. Commercial development of this vaccine is in progress. The success achieved with the T. ovis vaccine augurs well for the rapid development of other recombinant vaccines against cysticercosis caused by other taeniid species and against hydatidosis in animals.

Echinococcus granulosus infection in dogs in Tambool, Sudan.

In the Tambool area (Central eastern Sudan) a survey was made of the infection rate of Echinococcus granulosus in dogs. From the total of 49 dogs shot by the police authority, 25 (51%) had E. granulosus in their intestines. The range of worm recovery was 7 to 28,400. These high infection and recovery rates could be explained by the rate of infection in the intermediate host (camel) slaughtered in the area.

Population dynamics in echinococcosis and cysticercosis: mathematical model of the life-cycle of Echinococcus granulosus

A mathematical model of the life-cycle of Echinococcus granulosus in dogs and sheep in New Zealand is constructed and used to discuss previously published experimental and survey data. The model is then used to describe the dynamics of transmission of the parasite, and the means by which it may be destabilized. It is found that under the conditions that prevailed in New Zealand during the late 1950s, at the time of surveys of this parasite, the dog-sheep life-cycle was not regulated by any effective density-dependent constraint. In contrast there was evidence for an effective acquisition of immunity to reinfection by cattle. The long time to maturity of the cyst in sheep, together with the practice of feeding aged sheep to dogs, provides a time delay in the intermediate host. By comparison, the time to maturity of the adult stage in dogs is short, but it is of sufficient magnitude to be a key factor in the destabilization of the system by a regular dog-dosing programme. The model used to describe the life-cycle is a linear integrodifferential equation of the Volterra type. Such equations are intrinsically unstable in that a small perturbation in parameters can drive a previous equilibrium solution to zero. At the time of the surveys, the value of the basic reproductive rate, R0, was close to 1, and it has since been reduced below 1 by control measures.

Hydatid disease in the Turkana District of Kenya, IV. The prevalence of Echinococcus granulosus infections in dogs, and observations on the role of the dog in the lifestyle of the Turkana.

The prevalence of Echinococcus granulosus in dogs in the Turkana District of Kenya was 39.4% of 695 examined. Of these, 98 (35.8%) had heavy Echinococcus worm burdens (10(3)-5 X 10(4) ), while 54 (19.7%) and 122 (44.5%) had medium (201-1000) and light (1-200) burdens. The possible sources of these infections are discussed. The prevalence rate differed in various parts of the district, ranging from 63.5% in the northwest, where the highest incidence of human hydatidosis also occurs, to nil along the shores of Lake Turkana. Infection rates of 32.0% and 16.7% were recorded at Lokitaung (north-east) and Lodwar (central), while in the south 48.9% of dogs harboured Echinococcus. This latter figure is surprising as the area has a low incidence of human hydatidosis. The Turkana keep a large number of dogs, and the reasons for this and the social role of the dog in the district is discussed. No difference in susceptibility was found between Turkana-type dogs and those of mixed breeds from Nairobi when they were experimentally infected with hydatid protoscolices from man, camels, cattle, sheep and goats. However, it proved difficult to infect the Turkana-type of dogs with viable protoscolices of cattle origin. The reasons for this and its epidemiological implications remain unclear. It is suggested that droughts, which affect Turkana every six to ten years, may play an important role in the perpetuation of hydatid disease in the area.

Comparative strobilar development of Echinococcus granulosus of sheep origin from different geographical areas of Australia in vivo and in vitro

Consistent differences in the growth, segmentation and maturation of Echinococcus granulosus in dogs were demonstrated between the parasite of Tasmanian sheep origin and that of Eastern and Western Australian sheep origin. These results were complemented by in vitro studies which found that Tasmanian E. granulosus produced eggs approx. 7 days earlier than the parasite of Eastern and Western Australian origin. These results support the suggestion that at least two distinct strains of E. granulosus of domestic animal origin exist in Australia. The significance of the differences in development demonstrated in this study is discussed.

Possible factors influencing distribution and prevalence of Echinococcus granulosus in Utah.

A descriptive epidemiologic study was designed to test an impression that infections of Echinococcus granulosus in dogs, sheep, and human beings were concentrated in central Utah, and to determine when and how the parasite was introduced into the state, which factors were involved in the distribution of the cestode, and which factors increased either a person's risk of infection of the number of people at risk. Data were secured by review of available records, interviews, questionnaires, and field observations. It was found that 37 of 39 infections in human beings, and seven of eight counties with endemic hydatid disease in dogs and sheep, are located in central Utah. Possible factors responsible for the increasing number of people at risk were use of local people as herders, the existence of community herds, and specific dog management practices. Determinants such as trailing sheep between seasonal pastures, association of sheepmen from several counties on winter range, and sheep marketing practices undoubtedly influence distribution of infections in dogs and sheep.

Growth, segmentation and maturation of the British horse and sheep strains of Echinococcus granulosus in dogs

Growth, segmentation and maturation of the British horse and sheep strains of Echinococcus granulosus in dogs. International Journal for Parasitology 7: 281–285. Development of the British horse and sheep strains of Echinococcus granulosus in dogs was compared. Growth of the two strains did not differ significantly, but segmentation and maturation were both retarded in the horse strain compared with that of the sheep strain. These results emphasise the existence of physiological differences between the two strains, and illustrate the independence of somatic growth, somatic differentiation and germinal differentiation in vivo. The ability of both strains to enter crypts of Lieberkühn as early as 6 h p.i. was observed.