Review and update of paramphistomosis

Despite records of ruminal paramphistomes in Argentina dating back to the beginning of the XX century, in the last decade cases have increased in number with evidence of spreading to new geographical areas. This fact led us to carry out some studies in the last few years in order to enhance the poor availability of reports in South America, some of which are actually performed in our group. This paper reviews the characteristics of the life cycles and some aspects of the disease both at world and local level, and updates the latest paramphistome reports in domestic ruminants of Argentina.Facultad de Ciencias VeterinariasCentro de Diagnóstico e Investigaciones Veterinaria

First report of Paramphistomum leydeni Näsmark, 1937 (Trematoda: Paramphistomidae) in Argentina, and re-examination of Cotylophoron cotylophorum sensu Racioppi et al. (1994)

Cotylophoron cotylophorum and Balanorchis anastrophus are the only amphistomes of ruminants that have been described so far in Argentina. Recent observations suggest that C. cotylophorum could have been misclassified. To confirm this, we examined specimens, collected in Corrientes Province and classified by Racioppi et al. (1994) as Cotylophoron cotylophorum, and re-classified these as Paramphistomum leydeni Näsmark, 1937. Flukes collected from Zárate (Buenos Aires) were also studied and compared against the former, resulting in the same species. The present study reports the existence of P. leydeni in Argentina, modifies the previous classification of C. cotylophorum and suggests that, based on the evidence of the amphistomes described so far, P. leydeni would be the most prevalent species in cattle of Argentina.Facultad de Ciencias VeterinariasCentro de Estudios Parasitológicos y de Vectore

First report of Paramphistomum leydeni Näsmark, 1937 (Trematoda: Paramphistomidae) in Argentina, and re-examination of Cotylophoron cotylophorum sensu Racioppi et al. (1994)

Cotylophoron cotylophorum and Balanorchis anastrophus are the only amphistomes of ruminants that have been described so far in Argentina. Recent observations suggest that C. cotylophorum could have been misclassified. To confirm this, we examined specimens, collected in Corrientes Province and classified by Racioppi et al. (1994) as Cotylophoron cotylophorum, and re-classified these as Paramphistomum leydeni Näsmark, 1937. Flukes collected from Zárate (Buenos Aires) were also studied and compared against the former, resulting in the same species. The present study reports the existence of P. leydeni in Argentina, modifies the previous classification of C. cotylophorum and suggests that, based on the evidence of the amphistomes described so far, P. leydeni would be the most prevalent species in cattle of Argentina.Facultad de Ciencias VeterinariasCentro de Estudios Parasitológicos y de Vectore

Review and update of paramphistomosis

Despite records of ruminal paramphistomes in Argentina dating back to the beginning of the XX century, in the last decade cases have increased in number with evidence of spreading to new geographical areas. This fact led us to carry out some studies in the last few years in order to enhance the poor availability of reports in South America, some of which are actually performed in our group. This paper reviews the characteristics of the life cycles and some aspects of the disease both at world and local level, and updates the latest paramphistome reports in domestic ruminants of Argentina.Facultad de Ciencias VeterinariasCentro de Diagnóstico e Investigaciones Veterinaria

Fasciola hepatica: Variations in redial development and cercarial production in relation to the geographic origin of the parasite

Two hundred Galba truncatula, originating from a French population, were subjected to single-miracidium infections with an allopatric isolate (origin, Argentina) of Fasciola hepatica. The control group was constituted by 100 snails coming from the same population and exposed to sympatric miracidia of F. hepatica according to the same protocol. Snail samples were collected bimonthly from both groups between day 14 and day 112 p.e. (at 20 C) and snail dissections were performed to count free rediae, intraredial morulae and free cercariae. Third and fourth generation rediae were significantly more numerous in the allopatric group, while the number of first generation rediae was significantly lower. In the sympatric group, the decrease in the number of intraredial morulae in the first, second and third redial generations was significantly faster. Free cercariae within the snail body were significantly more numerous in the sympatric than in the allopatric groups, whatever the date of snail dissection. The changes in redial development and cercarial production noted in the Argentinean group might be due to the evolution of South American flukes in a divergent way after the introduction of foreign infected ruminants in this continent from the 15th century.Facultad de Ciencias Veterinaria

Fasciola hepatica: Variations in redial development and cercarial production in relation to the geographic origin of the parasite

Two hundred Galba truncatula, originating from a French population, were subjected to single-miracidium infections with an allopatric isolate (origin, Argentina) of Fasciola hepatica. The control group was constituted by 100 snails coming from the same population and exposed to sympatric miracidia of F. hepatica according to the same protocol. Snail samples were collected bimonthly from both groups between day 14 and day 112 p.e. (at 20 C) and snail dissections were performed to count free rediae, intraredial morulae and free cercariae. Third and fourth generation rediae were significantly more numerous in the allopatric group, while the number of first generation rediae was significantly lower. In the sympatric group, the decrease in the number of intraredial morulae in the first, second and third redial generations was significantly faster. Free cercariae within the snail body were significantly more numerous in the sympatric than in the allopatric groups, whatever the date of snail dissection. The changes in redial development and cercarial production noted in the Argentinean group might be due to the evolution of South American flukes in a divergent way after the introduction of foreign infected ruminants in this continent from the 15th century.Facultad de Ciencias Veterinaria

First report of pre-Hispanic Fasciola hepatica from South America revealed by ancient DNA

It is generally assumed that the digenean human liver fluke, Fasciola hepatica, gained entry to South America during the 15th century upon arrival of Europeans and their livestock. Nonetheless in Patagonia, Argentina, digenean eggs similar to F. hepatica have been observed in deer coprolites dating back to 2300 years B.P. The main objective of our present study was to identify and characterize these eggs using an ancient DNA (aDNA) study. Eggs were isolated and used for aDNA extraction, amplification and sequencing of partial regions from the cytochrome c oxidase subunit 1 and the nicotinamide adenine dinucleotide dehydrogenase subunit 1 mitochondrial genes. Also, phylogenetic trees were constructed using Bayesian and maximum likelihood. Our results confirm the presence of F. hepatica in South America from at least 2300 years B.P. This is the first report and the first aDNA study of this trematode in South America prior to the arrival of the European cattle in the 15th century. The present work contributes to the study of phylogenetic and palaeobiogeographical aspects of F. hepatica and its settlement across America.Fil: Beltrame, Maria Ornela. Universidad Nacional de Mar del Plata. Facultad de Cs.exactas y Naturales. Instituto de Investigaciones En Sanidad Produccion y Ambiente. - Comision de Investigaciones Cientificas de la Provincia de Buenos Aires. Instituto de Investigaciones En Sanidad Produccion y Ambiente.; ArgentinaFil: Pruzzo, César. Universidad Nacional de La Plata; ArgentinaFil: Sanabria, Rodrigo Eduardo Fabrizio. Universidad Nacional de San Martin. Instituto Tecnologico de Chascomus. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - la Plata. Instituto Tecnologico de Chascomus.; ArgentinaFil: Pérez, Alberto. Universidad Católica de Temuco; ChileFil: Mora, Matias Sebastian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentin

First report of Paramphistomum leydeni Näsmark, 1937 (Trematoda: Paramphistomidae) in Argentina, and re-examination of Cotylophoron cotylophorum sensu Racioppi et al. (1994)

Cotylophoron cotylophorum and Balanorchis anastrophus are the only amphistomes of ruminants that have been described so far in Argentina. Recent observations suggest that C. cotylophorum could have been misclassified. To confirm this, we examined specimens, collected in Corrientes Province and classified by Racioppi et al. (1994) as Cotylophoron cotylophorum, and re-classified these as Paramphistomum leydeni Näsmark, 1937. Flukes collected from Zárate (Buenos Aires) were also studied and compared against the former, resulting in the same species. The present study reports the existence of P. leydeni in Argentina, modifies the previous classification of C. cotylophorum and suggests that, based on the evidence of the amphistomes described so far, P. leydeni would be the most prevalent species in cattle of Argentina.Facultad de Ciencias VeterinariasCentro de Estudios Parasitológicos y de Vectore

Identification of a field isolate of Fasciola hepatica resistant to albendazole and susceptible to triclabendazole

The experiments described here were designed to characterize the status of susceptibility/resistance to albendazole (ABZ) and triclabendazole (TCBZ) of a Fasciola hepatica isolate (named CEDIVE isolate) recovered from infected sheep (Gualeguay, Argentina) and maintained under laboratory conditions. Two separate clinical efficacy experiments were performed on sheep artificially infected with the CEDIVE isolate. Experiment 1: Sheep were randomly distributed either in an untreated control group or an ABZ (7.5 mg/kg) treated group (n= 4 each). Additionally, the systemic exposure of ABZ metabolites was assessed in those ABZ-treated infected animals. In Experiment 2, an untreated control group and a TCBZ (10 mg/kg) treated group was included (n = 4 each). The fluckicidal efficacy of ABZ and TCBZ was assessed by comparison of the number of flukes recovered from untreated and treated sheep at 15 days post-treatment. The efficacy against the CEDIVE isolate of F. hepatica was 29% (ABZ) and 100% (TCBZ). The plasma drug exposure (expressed as AUC and Cmax) observed in the ABZ treated animals (Experiment 1), was in agreement with data obtained in previous studies, which indicate that the low ABZ efficacy was not related to the quality of the pharmaceutical product and/or to a low systemic availability of the active drug/metabolite. The results reported here, clearly show that the CEDIVE isolate of F. hepatica behaves as resistant to ABZ and susceptible to TCBZ.Fil: Sanabria, Rodrigo Eduardo Fabrizio. Universidad Nacional de la Plata. Facultad de Ciencias Veterinarias; Argentina;Fil: Ceballos, Laura. Universidad Nacional del Centro de la Provincia de Buenos Aires.. Facultad de Ciencias Veterinarias. Departamento de Fisiopatologia. Laboratorio de Farmacologia; Argentina;Fil: Moreno, Laura. Universidad Nacional del Centro de la Provincia de Buenos Aires.. Facultad de Ciencias Veterinarias. Departamento de Fisiopatologia. Laboratorio de Farmacologia; Argentina;Fil: Romero, Jorge Marcelo. Universidad Nacional de la Plata. Facultad de Ciencias Veterinarias; Argentina;Fil: Lanusse Carlos. Universidad Nacional del Centro de la Provincia de Buenos Aires.. Facultad de Ciencias Veterinarias. Departamento de Fisiopatologia. Laboratorio de Farmacologia; Argentina;Fil: Alvarez Luis. Universidad Nacional del Centro de la Provincia de Buenos Aires.. Facultad de Ciencias Veterinarias. Departamento de Fisiopatologia. Laboratorio de Farmacologia; Argentina

Identification of a field isolate of Fasciola hepatica resistant to albendazole and susceptible to triclabendazole

The experiments described here were designed to characterize the status of susceptibility/resistance to albendazole (ABZ) and triclabendazole (TCBZ) of a Fasciola hepatica isolate (named CEDIVE isolate) recovered from infected sheep (Gualeguay, Argentina) and maintained under laboratory conditions. Two separate clinical efficacy experiments were performed on sheep artificially infected with the CEDIVE isolate. Experiment 1: Sheep were randomly distributed either in an untreated control group or an ABZ (7.5 mg/kg) treated group (n= 4 each). Additionally, the systemic exposure of ABZ metabolites was assessed in those ABZ-treated infected animals. In Experiment 2, an untreated control group and a TCBZ (10 mg/kg) treated group was included (n = 4 each). The fluckicidal efficacy of ABZ and TCBZ was assessed by comparison of the number of flukes recovered from untreated and treated sheep at 15 days post-treatment. The efficacy against the CEDIVE isolate of F. hepatica was 29% (ABZ) and 100% (TCBZ). The plasma drug exposure (expressed as AUC and Cmax) observed in the ABZ treated animals (Experiment 1), was in agreement with data obtained in previous studies, which indicate that the low ABZ efficacy was not related to the quality of the pharmaceutical product and/or to a low systemic availability of the active drug/metabolite. The results reported here, clearly show that the CEDIVE isolate of F. hepatica behaves as resistant to ABZ and susceptible to TCBZ.Facultad de Ciencias Veterinaria