Echinococcus granulosus: biological comparison of cattle isolates from endemic regions of Argentina and Spain / Echinococcus granulosus: comparación biológica de aislados de bovinos de regiones endémicas de Argentina y España

In the present study we have compared cattle isolates of Echinococcus granulosus from Argentina and Spain. The aim was to compare and determine if there exist phenotypic and genetic differences within E. granulosus cattle isolates between an endemic area of Spain (where the disease is mainly restricted to a sheep-dog cycle) and an endemic area of Argentina (where cattle are the most abundant intermediate hosts). The Spanish samples were previously identified as G1 genotype. The Argentinean samples were also identified as G1, but some variants were found for the cytochrome c oxidase-1 (CO1) and NADH dehydrogenase-1 (ND1) mitochondrial genes. When comparing the cyst features and the morphology of the larval rostellar hooks in both regions, some differences were found. The morphometric analyses of the larval rostellar hooks showed the existence of two distinct clearly separated groups (one corresponding to the Argentinean samples and the other to the Spanish ones). In conclusion, there are some genetic and phenotypic differences within E. granulosus cattle isolates from Argentina and Spain. Probably these differences, more important from an epidemiological point of view, are related to different steps in the disease control in both countries. Further studies involving other epidemiological, morphometric and molecular data, including other types of livestock, would contribute to clarify and expand the present work.

El objetivo del presente trabajo fue determinar si existen diferencias fenotípicas y genéticas entre los aislados de Echinococcus granulosus de origen bovino provenientes de dos regiones geográficas donde la hidatidosis es endémica, una de España (donde predomina el ciclo perro-oveja) y una de Argentina (donde el bovino es el hospedador intermediario más importante). Las muestras españolas fueron previamente identificadas como pertenecientes al genotipo G1. Las muestras argentinas también correspondían al genotipo G1, pero entre ellas se registraron algunas microvariantes de los genes mitocondriales citocromo c oxidasa-1 (CO1) y NADH deshidrogenasa- 1 (ND1). La comparación de las características de los quistes y de la morfología de los ganchos rostelares del metacestode mostró ciertas diferencias. En conclusión, existen algunas diferencias genéticas y fenotípicas entre los aislados de E. granulosus de Argentina y España. Probablemente estas diferencias, más importantes desde el punto de vista epidemiológico, podrían estar relacionadas con diferentes etapas en los programas de control de la enfermedad en los dos países. Estudios adicionales que involucren datos epidemiológicos, morfométricos y moleculares provenientes de otros tipos de ganado contribuirán a clarificar y ampliar la información aportada por este trabajo.

Pediatric hydatidosis in the south-east of the Buenos Aires province, Argentina.

Hydatidosis is a zoonosis produced by the metacestode Echinococcus spp. The aims of this research are: to contribute to the knowledge of pediatric hydatidosis in the south-east of Buenos Aires province, to study its evolution from 1993 to 2002 at the Regional Maternity and Pediatric Hospital "Dr. Victorio Tetamanti", to determine the strains involved and to discuss the importance of the disease. The clinical records of diagnosed and/or operated patients were reviewed with regard to the hydatid disease. The strain was determined by using PCRs with Eg1 121a/122a primers. Forty-four cases were analyzed. Fifty nine point one per cent of the patients were boys. The mean age was 8 SD=3.8 years. Sixty one point four per cent had urban residence. Ultrasonography was used in 61% of the cases. The hepatic location was most frequently seen and the liver/lung ratio was 1.25. Ninety point nine per cent of patients received surgical treatment. Albendazole was used in 52% of cases. The average hospitalization time was 11 days. The G1/G2 strain group was determined. This report is the first one of its kind in the studied region. The permanence of hydatidosis in the region depends on the natural transmission of the parasite in the absence of control and prevention measures. The health authorities should implement strategies of prevention and control in the study area.

Pediatric hydatidosis in the south-east of the Buenos Aires province, Argentina / Hidatidosis pediátrica en el sudeste de la provincia de Buenos Aires, Argentina

Hydatidosis is a zoonosis produced by the metacestode Echinococcus spp. The aims of this research are: to contribute to the knowledge of pediatric hydatidosis in the south-east of Buenos Aires province, to study its evolution from 1993 to 2002 at the Regional Maternity and Pediatric Hospital "Dr. Victorio Tetamanti", to determine the strains involved and to discuss the importance of the disease. The clinical records of diagnosed and/or operated patients were reviewed with regard to the hydatid disease. The strain was determined by using PCRs with Eg1 121a/122a primers. Forty-four cases were analyzed. Fifty nine point one per cent of the patients were boys. The mean age was 8 SD=3.8 years. Sixty one point four per cent had urban residence. Ultrasonography was used in 61% of the cases. The hepatic location was most frequently seen and the liver/lung ratio was 1.25. Ninety point nine per cent of patients received surgical treatment. Albendazole was used in 52% of cases. The average hospitalization time was 11 days. The Gl/G2 strain group was determined. This report is the first one of its kind in the studied region. The permanence of hydatidosis in the region depends on the natural transmission of the parasite in the absence of control and prevention measures. The health authorities should implement strategies of prevention and control in the study area.

Los objetivos de este trabajo fueron: contribuir al conocimiento de la hidatidosis pediátrica en el sudeste de la provincia de Buenos Aires, estudiar su evolución desde 1993 hasta 2002, establecer la o las cepas involucradas y discutir la importancia de la enfermedad. Para ello se revisaron las historias clínicas de los pacientes pediátricos con diagnóstico de hidatidosis asistidos en el Hospital Interzonal Especializado Materno Infantil "Dr. Victorio Tetamanti" durante ese período. Se analizaron 44 casos, el 59,1% de ellos correspondió a varones. La media de edad fue de 8 años (SD=3,8 años) y el 61,4% de los niños afectados eran de residencia urbana. Se empleó ultrasonografía como método diagnóstico en el 61% de los casos. La localización hepática fue la más frecuente y la relación hígado/pulmón fue 1,25. El 90,9% recibió tratamiento quirúrgico. Se utilizó albendazol en el 52% de los pacientes. El tiempo de hospitalización tuvo una mediana de 11 días. Las cepas se determinaron mediante PCR con los cebadores Eg1 121a/122a. Se determinó la presencia de cepas del grupo G1/G2, dato informado por primera vez en humanos para la región de estudio. Se concluyó que la permanencia de la enfermedad en la región depende de la transmisión natural del parásito en ausencia de medidas de control y prevención. Por consiguiente, las autoridades de salud deberían implementar estrategias de prevención y control en dicha zona.

Echinococcus granulosus: biological comparison of cattle isolates from endemic regions of Argentina and Spain.

In the present study we have compared cattle isolates of Echinococcus granulosus from Argentina and Spain. The aim was to compare and determine if there exist phenotypic and genetic differences within E. granulosus cattle isolates between an endemic area of Spain (where the disease is mainly restricted to a sheep-dog cycle) and an endemic area of Argentina (where cattle are the most abundant intermediate hosts). The Spanish samples were previously identified as G1 genotype. The Argentinean samples were also identified as G1, but some variants were found for the cytochrome c oxidase-1 (CO1) and NADH dehydrogenase-1 (ND1) mitochondrial genes. When comparing the cyst features and the morphology of the larval rostellar hooks in both regions, some differences were found. The morphometric analyses of the larval rostellar hooks showed the existence of two distinct clearly separated groups (one corresponding to the Argentinean samples and the other to the Spanish ones). In conclusion, there are some genetic and phenotypic differences within E. granulosus cattle isolates from Argentina and Spain. Probably these differences, more important from an epidemiological point of view, are related to different steps in the disease control in both countries. Further studies involving other epidemiological, morphometric and molecular data, including other types of livestock, would contribute to clarify and expand the present work.

In vitro and in vivo effects of flubendazole on Echinococcus granulosus metacestodes.

The aim of the present work was to determine the efficacy of flubendazole (FLBZ) against Echinococcus granulosus metacestodes by using in vitro and in vivo models. Groups of 50 microcysts developed in vitro, and groups of 10 peritoneal cysts were obtained from Balb C mice with experimental secondary infections of 8 months. The cysts were placed in Leighton tubes containing 10 ml of culture medium. FLBZ was added to the medium resulting in final concentrations of 5 and 1 microg/ml for mycrocysts treatment and 10, 5, and 1 microg/ml for murine cysts treatment. In vivo treatment was performed on 20 mice that developed an experimental secondary hydatid disease over a period of 11 months. FLBZ was given (1.5 mg/kg) by the oral route once a day for 50 days. A loss of turgidity was detected in all in vitro drug treated cysts irrespective of the drug concentration or parasite origin. Inspection of treated cysts by scanning electron microscopy (SEM) revealed that the germinal layer lost it characteristic multicelular structure. These results were confirmed on the ultrastructural level by transmission electron microscopy (TEM), treated metacestodes had undergone considerable degenerative changes after the in vitro treatment. The results obtained after the in vivo treatment with FLBZ showed no significant difference between the control and treated groups related to the weight of cyst masses. However, the ultrastructural study at TEM of cysts that developed in mice from the treated group revealed alterations in the germinal layer with the presence of numerous vacuoles. With regard to the ultrastructural study at SEM, only cellular debris of the germinal layer could be seen. In conclusion, the data obtained clearly demonstrate that in vitro and in vivo treatment with FLBZ is effective against E. granulosus metacestodes.

In vitro effects of flubendazole on Echinococcus granulosus protoscoleces.

The aim of the present work was to determine the in vitro protoscolicidal effect of flubendazole (FLBZ) against Echinococcus granulosus. Protoscoleces of E. granulosus were incubated with FLBZ at concentrations of 10, 5 and 1 microg/ml. The first signs of FLBZ-induced damage were observed 3 days post-incubation. A clear protoscolicidal effect, reducing the vitality of protoscoleces to 35.6+/-0.7%, was observed after 18 days of incubation. After 25 days of FLBZ incubation (5 microg/ml), the percentage of vital protoscoleces was 13.9+/-5.9%. Protoscolex mortality was 100% (10 and 1 microg/ml) and 0.7+/-0.7% (5 microg/ml) after FLBZ incubation for 30 days. Results of vitality tests were consistent with the tissue damage observed at the ultrastructural level. The primary site of damage was the tegument of the parasite. The morphological changes included contraction of the soma region, formation of blebs on the tegument, rostellar disorganization, loss of hooks and destruction of microtriches. The data reported in this article demonstrate a clear in vitro effect of FLBZ against E. granulosus protoscoleces.

Strain characterization of Echinococcus granulosus protoscoleces of cattle origin using the in vitro vesicular development.

The aim of this work was to characterize the strain of protoscoleces of E. granulosus of cattle origin using the in vitro vesicular development. The in vitro development of these samples was compared to samples of sheep origin determined previously by genetic analyses as common sheep strain (G1). There were similarities between sheep and cattle samples not only in the time of microcysts formation, but also in the development process. Vesiculated protoscoleces and protoscoleces with posterior bladders appeared during the first week of incubation. After 14 days of culture, a laminated layer appeared like a fine membrane in one of the extremes of the protoscoleces. In the sheep samples, microcysts were observed between 19 and 20 days. In the cattle samples, microcysts appeared between 20 and 23 days. The coincidence between the development times and physiological characteristics found in the present study may indicate that the parasites from cattle and sheep were of the same strain.

Echinococcus granulosus: first report of microcysts formation from protoscoleces of cattle origin using the in vitro vesicular culture technique.

The aim of this work was the achievement of microcysts formation from protoscoleces of E. granulosus of cattle origin using the in vitro vesicular culture technique. Vesiculated protoscoleces and protoscoleces with posterior bladders appeared during the first week of incubation. After 14 days of culture, a laminated layer appeared like a fine membrane in one of the extremes of the protoscoleces. On day 20, some microcysts with a complete laminated layer were observed. By day 48, microcysts completely developed could be observed. This is the first study where microcysts formation was obtained using protoscoleces of E. granulosus of cattle origin.

Viscachataenia n. g., with the redescription of V. quadrata (von Linstow, 1904) n. comb. (Cestoda: Anoplocephalidae) in Lagidium viscacia (Rodentia: Chinchillidae) from Argentina.

A new genus, Viscachataenia, is erected to accommodate the anoplocephalid cestode Cittotaenia quadrata von Linstow, 1904, based on a redescription of the species from material collected from the chinchillid rodent Lagidium viscacia in Argentina. The new genus is characterised by paired genitalia, a reticulate uterus and the vagina entering the genital atrium anterior to the cirrus-sac. Viscachataenia therefore has similarities with Monoecocestus Beddard, 1914, a genus which is common in South American rodents but which has a single set of genitalia in each segment. Cittotaenia viscaciae (Spasskii, 1951) and Bertiella findlayi Mazza, Parodi & Fiora, 1932, also from viscachas, are considered synonyms of V. quadrata.

Hypobiosis induction alters the protein profile of Ostertagia ostertagi (Nematoda: Trichostrongylidae).

The appearance of variations in the protein profile of Ostertagia ostertagi (Stiles, 1892) infective larvae (L3), which were induced by hypobiosis triggering factors, was evaluated by means of SDS-PAGE and densitometric analysis. Area integration analyses of their protein profiles was carried out between 66 and 77 kDa. Important quantitative variations were identified in the protein levels of the induced larvae, where a 5.25 fold increase compared to the control was observed. Two 75.4 and 70 kDa protein bands were found which exceeded the control profile by 4.5 and 44 fold, respectively. This fact suggests that the changes brought about in the process of hypobiosis induction are restricted. This work demonstrates changes at a molecular level corresponding with biological changes induced by conditions causing O. ostertagi hypobiosis.