RESUMO
Between 1898 and 1940, eight human cases of diphyllobothriasis were reported in Argentina, always in recently arrived European immigrants. In 1982, the first autochthonous case was detected, and since then, 33 other autochthonous cases have been reported, totaling 42 cases of human diphyllobothriasis in Argentina before the present study. Our aim is to update the information on diphyllobothriasis in Argentina by identifying specimens from new cases using morphometrical and/or molecular methods. We also aim to assess the epidemiological relevance of this food-borne disease in the country. Anamnestic data were obtained from patients or professionals, along with 26 worms identified using morphometrical (21 samples) and molecular techniques (5 samples). All the patients acquired the infection by consuming freshwater salmonids caught in Andean lakes in Northern Patagonia. Morphometrics and DNA markers of worms were compatible with Dibothriocephalus latus. In total, 68 human cases have been detected in Argentina, 60 of which were autochthonous. The human population living North-western Patagonia, whose lakes are inhabited by salmonids, is increasing. Similarly, the number of other definitive hosts for Dibothriocephalus dendriticus (gulls) and for D. latus (dogs) is also increasing. In addition, salmonid fishing and the habit of consuming home-prepared raw fish dishes are becoming widespread. Therefore, it is to be expected that diphyllobothriasis in Argentina will increase further.
Assuntos
Difilobotríase , Diphyllobothrium , Argentina/epidemiologia , Difilobotríase/epidemiologia , Difilobotríase/parasitologia , Humanos , Animais , Masculino , Feminino , Diphyllobothrium/genética , Diphyllobothrium/isolamento & purificação , Diphyllobothrium/classificação , Adulto , Pessoa de Meia-Idade , Idoso , Salmonidae/parasitologia , Doenças Transmitidas por Alimentos/parasitologia , Doenças Transmitidas por Alimentos/epidemiologia , Adulto Jovem , História do Século XX , História do Século XIXRESUMO
Diphyllobothriosis is a reemerging zoonotic disease because of global trade and increased popularity of eating raw fish. We present molecular evidence of host switching of a human-infecting broad fish tapeworm, Dibothriocephalus latus, and use of salmonids as intermediate or paratenic hosts and thus a source of human infection in South America.
Assuntos
Difilobotríase , Doenças dos Peixes/epidemiologia , Doenças dos Peixes/parasitologia , Interações Hospedeiro-Parasita , Salmonidae/parasitologia , Zoonoses/epidemiologia , Animais , Doenças dos Peixes/diagnóstico , Humanos , América do Sul/epidemiologiaRESUMO
Although various elements of the olfactory system have been elucidated in insects, it remains practically unstudied in crustaceans at a molecular level. Among crustaceans, some species are classified as ectoparasites that impact the finfish aquaculture industry. Thus, there is an urgent need to identify and comprehend the signaling pathways used by these in host recognition. The present study, through RNA-seq and qPCR analyses, found novel transcripts involved in the olfactory system of Caligus rogercresseyi, in addition to the transcriptomic patterns expressed during different stages of salmon lice development. From a transcriptomic library generated by Illumina sequencing, contigs that annotated for ionotropic receptors and other genes implicated in the olfactory system were identified and extracted. Full length mRNA was obtained for the ionotropic glutamate receptor 25, which had 3923 bp, and for the glutamate receptor ionotropic kainate 2, which had 2737 bp. Furthermore, two other transcripts identified as glutamate receptor, ionotropic kainate 2-like were found. In silico analysis was performed for the transcription expression from different stages of development in C. rogercresseyi, and clusters according to RPKM values were constructed. Gene transcription data were validated through qPCR assays in ionotropic receptors, and showed an expression of glutamate receptor 25 associated with the copepodid stage whereas adults, especially male adults, were associated with the kainate 2 and kainate 2-like transcripts. Additionally, gene transcription analysis of the ionotropic receptors showed an overexpression in response to the presence of masking compounds and immunostimulant in salmon diets. This response correlated to a reduction in sea lice infection following in vivo challenge. Diets with masking compounds showed a decrease of lice infestation of up to 25%. This work contributes to the available knowledge on chemosensory systems in this ectoparasite, providing novel elements towards understanding the host-finding process of the salmon louse C. rogercresseyi.
Assuntos
Copépodes/fisiologia , Ectoparasitoses/veterinária , Doenças dos Peixes/parasitologia , Salmonidae/parasitologia , Transcrição Gênica , Animais , Sequência de Bases , Copépodes/anatomia & histologia , Copépodes/genética , Ectoparasitoses/parasitologia , Feminino , Regulação da Expressão Gênica , Masculino , Dados de Sequência Molecular , Bulbo Olfatório/anatomia & histologia , Bulbo Olfatório/fisiologia , Neurônios Receptores Olfatórios/anatomia & histologia , Neurônios Receptores Olfatórios/fisiologia , Reação em Cadeia da Polimerase , RNA Mensageiro/química , RNA Mensageiro/genética , Receptores de Ácido Caínico/genética , Alinhamento de Sequência , Olfato/genética , Transcrição Gênica/genética , Transcriptoma/genéticaRESUMO
Understanding the molecular underpinnings involved in the reproduction of the salmon louse is critical for designing novel strategies of pest management for this ectoparasite. However, genomic information on sex-related genes is still limited. In the present work, sex-specific gene transcription was revealed in the salmon louse Caligus rogercresseyi using high-throughput Illumina sequencing. A total of 30,191,914 and 32,292,250 high quality reads were generated for females and males, and these were de novo assembled into 32,173 and 38,177 contigs, respectively. Gene ontology analysis showed a pattern of higher expression in the female as compared to the male transcriptome. Based on our sequence analysis and known sex-related proteins, several genes putatively involved in sex differentiation, including Dmrt3, FOXL2, VASA, and FEM1, and other potentially significant candidate genes in C. rogercresseyi, were identified for the first time. In addition, the occurrence of SNPs in several differentially expressed contigs annotating for sex-related genes was found. This transcriptome dataset provides a useful resource for future functional analyses, opening new opportunities for sea lice pest control.
Assuntos
Copépodes/genética , Salmonidae/parasitologia , Caracteres Sexuais , Transcriptoma/genética , Animais , Sequência de Bases , Feminino , Sequenciamento de Nucleotídeos em Larga Escala , Masculino , Dados de Sequência Molecular , Controle de Pragas/métodos , Polimorfismo de Nucleotídeo Único/genéticaRESUMO
Sea lice, Caligus rogercresseyi, are ectoparasitic copepods, which severely affect the salmon farming industry in southern Chile, reducing the health status of fish and producing both direct and indirect economic losses. Local farmers have reported increasing infestation levels since 2004, reaching a peak in 2007. In response to this situation, the Chilean Fisheries Service (Sernapesca) developed a surveillance programme; the first step of which consisted of a general survey of salmon farms. This survey included documenting counts of parasite burdens on fish and measurements of several husbandry and environmental factors providing an evaluation of risk factors for the observed infestation levels. The information collected was analysed using a linear mixed model technique, which takes into account the clustered structure of data, decomposing the unexplained variation and assigning it to different aggregation levels of the productive system. Geographical zones, fish species, treatment against sea lice performed 1 month before sampling, stocking density, fish weight and water salinity were the variables significantly associated with sea lice burdens. In contrast, treatments performed 2-3 months before sampling, use of photoperiod in sea cages and water temperature, were not significant. There was significant unexplained variation at all aggregation levels, i.e. sub-zone, fish farm and cage level, with the fish farm level showing the greatest variation.
Assuntos
Copépodes , Ectoparasitoses/veterinária , Doenças dos Peixes/epidemiologia , Pesqueiros , Salmonidae/parasitologia , Animais , Chile/epidemiologia , Análise por Conglomerados , Estudos Transversais , Ectoparasitoses/tratamento farmacológico , Ectoparasitoses/epidemiologia , Doenças dos Peixes/tratamento farmacológico , Doenças dos Peixes/parasitologia , Modelos Lineares , Vigilância da População , Fatores de RiscoRESUMO
A total of 228 salmonids (90 Oncorhynchus mykiss, 48 Oncorhynchus kisutch, and 90 Salmo salar) from 8 intensive aquaculture centers in the south of Chile were examined for endohelminths parasites between December 2008 and May 2009. The body cavities of 2 O. mykiss were infected by Diphyllobothrium sp. plerocercoids (prevalence: 6.7%, mean intensity: 1.0, mean abundance: 0.07) from the Lake Tarahuin hatchery on the south of Chiloé Island. Also, tetraphyllidean plerocercoids (prevalence: 3.3%, mean intensity: 1, mean abundance: 0.03) and fourth-stage larvae of Hysterothylacium aduncum (prevalence: 6.7%, mean intensity: 1, mean abundance 0.07) were observed in O. kisutch from a marine hatchery in Chiloé. The occurrences of Diphyllobothrium sp. in a lake and a tetraphyllidean plerocercoid from marine cultured salmonid in Chiloé are reported for first time. No muscular infection by helminths was recorded in the fish examined.
Assuntos
Doenças dos Peixes/parasitologia , Pesqueiros , Helmintíase Animal/parasitologia , Salmonidae/parasitologia , Animais , Infecções por Ascaridida/epidemiologia , Infecções por Ascaridida/parasitologia , Infecções por Ascaridida/veterinária , Ascaridoidea/isolamento & purificação , Cestoides/isolamento & purificação , Infecções por Cestoides/epidemiologia , Infecções por Cestoides/parasitologia , Infecções por Cestoides/veterinária , Chile/epidemiologia , Difilobotríase/epidemiologia , Difilobotríase/parasitologia , Difilobotríase/veterinária , Diphyllobothrium/isolamento & purificação , Doenças dos Peixes/epidemiologia , Água Doce , Helmintíase Animal/epidemiologia , Oncorhynchus kisutch/parasitologia , Oncorhynchus mykiss/parasitologia , Prevalência , Salmo salar/parasitologia , Vísceras/parasitologiaRESUMO
Seasonal samples of all fish species from Lake Moreno were taken in order to determine the presence of paratenia, to evaluate the status of the hosts and to characterise the transmission of Acanthocephalus tumescens (von Linstow, 1896) at the component population level. Prevalence, mean abundance, mean intensity, numbers of gravid females, relative abundance of the different fish species, relative output of eggs and relative flow rates for each host species were computed. Acanthocephalus tumescens showed low host specificity, successfully parasitizing six out of eight fish species present in the lake. No paratenic infection was registered. If prevalence, mean abundance, and number of gravid females are considered, host species can be placed in a continuum from the most to least suitable as follows: Galaxias platei Steindachner, Diplomystes viedmensis (Mac Donagh), Oncorhynchus mykiss (Walbaum), Salvelinus fontinalis (Mitchill), Percichthys trucha (Cuvier et Valenciennes) and Galaxias maculatus (Jenyns). However, when parasite flow rates and egg output were calculated, including relative abundance of each fish species, the continuum was rearranged as follows: P. trucha, O. mykiss, G. platei / G. maculatus, S. fontinalis and D. viedmensis. The first four species would be the main contributors to the population of A. tumescens in this lake, P. trucha being the major one. Different regulatory and non-regulatory mechanisms are suggested.
Assuntos
Acantocéfalos/crescimento & desenvolvimento , Peixes/parasitologia , Animais , Argentina , Feminino , Água Doce , Interações Hospedeiro-Parasita , Intestinos/parasitologia , Masculino , Osmeriformes/parasitologia , Salmonidae/parasitologiaRESUMO
Four species of adult digeneans are reported from freshwater fishes of two lakes in Neuquén, Patagonia, Argentina. Allocreadium patagonicum sp. n. (Allocreadiidae) is described from the intestine of Percichthys colhuapiensis MacDonagh and Percichthys trucha (Cuvier et Valenciennes) (Percichthyidae) from Lago Aluminé. Three species redescribed are: Acanthostomoides apophalliformis Szidat, 1956 (Acanthostomidae) from the intestine of P. colhuapiensis and P. trucha from Lago Aluminé and of Salmo trutta (Linnaeus) (Salmonidae) from Lago Huechulafquén; Deropegus patagonicus (Szidat, 1956) comb. n. (= Genarches patagonicus Szidat, 1956) (Derogenidae) from the stomach of P. colhuapiensis, P. trucha, Oncorhynchus mykiss (Walbaum) (Salmonidae) and Salvelinus fontinalis (Mitchill) (Salmonidae) from Lago Aluminé and of S. trutta from Lago Huechulafquén; and Austrocreadium papilliferum Szidat, 1956 from the intestine of P. trucha from Lago Aluminé. The genus Polylekithum Arnold, 1934 is considered a synonym of the genus Allocreadium Looss, 1900. The genus Austrocreadium Szidat, 1956 is removed to the family Homalometridae.
Assuntos
Doenças dos Peixes/parasitologia , Salmonidae/parasitologia , Trematódeos/classificação , Infecções por Trematódeos/veterinária , Animais , Argentina , Água Doce , Intestinos/parasitologia , Oncorhynchus mykiss/parasitologia , Trematódeos/anatomia & histologia , Trematódeos/isolamento & purificação , Infecções por Trematódeos/parasitologiaRESUMO
OBJECTIVE: In view of the amateur fishing practices and the importance of salmonids in the region the study sets out to detect human hosts in the Andean-Patagonian zone. MATERIAL AND METHOD: Information campaigns were carried out by Clinical Analysis Laboratories of Andean Patagonia between 1986 and 1995 to detect diphyllobothriasis more efficiently by means of coproparasitological analysis. RESULTS: Further, forms were prepared for the collection of information about infection, treatment and the characteristics of the human host. During this period 13 new cases were registered either through direct identification of the parasite or through the presence of eggs in the faeces. The characteristics of infection are similar to those described for the genus Diphyllobothrium. CONCLUSIONS: The favourite game fish in Andean Patagonia are salmonids. This fish, often infected with plerocercoids, when eaten insufficiently cooked or cold smoked, constitutes the main source of human infection.
Assuntos
Difilobotríase/epidemiologia , Adolescente , Adulto , Animais , Argentina/epidemiologia , Difilobotríase/parasitologia , Diphyllobothrium/citologia , Reservatórios de Doenças/veterinária , Feminino , Doenças dos Peixes , Pesqueiros , Parasitologia de Alimentos , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Prevalência , Salmonidae/parasitologiaRESUMO
El objetivo del trabajo fué detectar hospedadores humanos en la zona andino patagónica argentina, teniendo en cuenta las prácticas de pesca desportiva y la importancia de los salmónidos dentro de la zona. entre 1986 y 1995 se implementaron Campañas de Información en los laboratorios de Análisis Clínicos de la región andinopatogónica argentina, destinadas a lograr una detección más eficiente de la difilobotriasis, a través de análisis coproparasitológicos. Adicionalmente, se confeccionaron planillas destinadas a recoger información sobre las características de la infección, del tratamiento y del paciente. Durante este período se detectaron 13 nuevos casos humanos, por identificación directa del parásito o por la presencia de huevos en materia fecal. Las características de las infecciones responden a las descriptas para el género Diphyllobothrium. En la región, los salmónidos son los peces predilectos en la pesca deportiva. Estos peces, frecuentemente parasitados con larvas, constituyen la principal fuente de contagio para el hombre al ser consumidos insuficientemente cocidos o ahumados en frío