ABSTRACT
Abstract Trichuris guanacastei n sp., a parasite isolated from the Salvin' spiny mouse Heteromys salvini, collected from the Guanacaste Conservation Area, Costa Rica, during February 1996 is described. The new species was compared morphologically with the 29 known species that parasitize rodents distributed in 12 families in North and South America; T. guanacastei n. sp. it is characterized by the following set of traits: presence of a spicular tube (measuring 0.72-0.99); thick proximal cloacal tube and a short distal cloacal tube with a total length of 0.72-1.36; eggs 0.03-0.05 long and a semi-protrusible vulva. The new species represents the first one described in the genus in Costa Rica and the fifth one described in the Americas that parasite Heteromyidae.
Resumo O objetivo deste estudo foi descrever Trichuris guanacastei n. sp., um parasita isolado do rato espinhoso de Salvin, Heteromys salvini, coletado na Área de Conservação de Guanacaste, Costa Rica, durante fevereiro de 1996. A nova espécie foi comparada morfologicamente a 29 espécies conhecidas que parasitam roedores, distribuídas em 12 famílias na América do Norte e do Sul. T. guanacastei n. sp. é caracterizado pelo seguinte conjunto de características: presença de um tubo espicular (que mede 0.72-0.99); tubo proximal cloacal e um tubo distal cloacal com uma longitude total de 0.72-1.36; ovos de 0.03-0.05 de largura e uma vulva semi-protrusible. A nova espécie representa a primeira descrita do gênero na Costa Rica e a quinta descrita nas Américas que parasita Heteromyidae.
Subject(s)
Animals , Female , Rodentia/parasitology , Trichuris/anatomy & histology , Trichuris/classification , Species Specificity , Costa RicaABSTRACT
Currently many species of Amazon sailfin catfishes (Loricariidae) have been introduced to wild environments outside their native range. There is, however, little knowledge about their role as vectors of parasites that can infect native fish or even humans through its consumption. The aim of the present study was to determine the parasitic fauna of the invasive sailfin catfish species Pterygoplichthys pardalis (leopard pleco) and P. disjunctivus (vermiculated pleco) from freshwater systems in the southeast of Mexico. Four ectoparasite species were found in P. pardalis (1 protozoan: Ichthyophthirius multifiliis ; 2 monogeneans: Urocleidoides vaginoclastrum and Heteropriapulus heterotylus ; 1 digenean: Clinostomum sp.), and only one in Heteropriapulus disjunctivus (H. heterotylus ). No endoparasites were found. Ichthyophthirius multifiliis , U. vaginoclaustrum and Clinostomum sp. , were considered as rare species (prevalence <5%) since they were found in a single individual of P. pardalis . H. heterotylus was the only species shared among both host species and it occurs throughout the year. This monogenean species represents 96% of total parasites recorded in P. pardalis and 100% in P. disjunctivus. Monthly values of prevalence, intensity and abundance of H. heterotylus in both host species showed important intra-annual variations, but not differ significantly between both hosts.(AU)
Actualmente muchas especies de peces conocidos como plecos o peces diablo (Loricariidae) han sido introducidas en ambientes silvestres fuera de su área de distribución natural. Sin embargo, hay poco conocimiento acerca de su papel como vectores de parásitos que puedan infectar a los peces nativos o incluso los seres humanos a través de su consumo. El objetivo del presente estudio fue determinar la fauna parasitaria de las especies de plecos Pterygoplichthys pardalis (pleco leopardo) y P. disjunctivus (pleco vermiculado) en sistemas de agua dulce del sureste de México. Fueron encontradas cuatro especies de ectoparásitos en P. pardalis (1 protozoario: Ichthyophthirius multifiliis ; 2 monogeneos: Urocleidoides vaginoclastrum y Heteropriapulus heterotylus ; 1 digeneo: Clinostomum sp.) y una en P. disjunctivus (H. heterotylus ). No se encontraron endoparásitos. Ichthyophthirius multifiliis, U. vaginoclaustrum y Clinostomum sp. fueron consideradas como especies raras (prevalencia <5%), ya que estuvieron en un solo individuo de P. pardalis . Heteropriapulus heterotylus fue la única especie compartida entre ambas especies de peces y que estuvo presente durante todo el año, y representó el 96% del total de parásitos registrados en P. pardalis y el 100% en P. disjunctivus. La prevalencia, intensidad media y abundancia media de H. heterotylus mostraron importantes variaciones intra-anuales en ambas especies de peces, pero no difirió significativamente entre ambos hospederos.(AU)
Subject(s)
Animals , Catfishes/parasitology , Parasitic Diseases, Animal/classification , Parasitic Diseases, Animal/diagnosisABSTRACT
Paragonimiasis is a zoonotic disease in Mexico caused by adult digeneans of Paragonimus mexicanus species. Life cycle of this parasite involves two necessary intermediate hosts: a snail and a crab, and a mammal serving as the definitive host. Humans acquire the infection when eating raw or undercooked crabs infected by metacercariae. In March 2005, six opossums (Didelphis virginiana) were captured in Colima, Mexico. These opossums were euthanized in order to identify lesions caused by lung paragonimiasis. Infected lungs were processed and stained following the standard histological techniques. Four of the six opossums (67%) carried 25 adult parasites identified as P. mexicanus. The lung with the greatest number of parasites showed 13 multifocally distributed granulomas. The main histological changes were: infiltration of monocytes, lymphocytes, macrophages, plasma cells, epithelioid and giant cells, abundant neutrophils and eosinophils, as well as central necrosis of the eosinophilic granuloma. Likewise, interstitial pneumonia was observed due to the presence of eggs between the granuloma walls and alveolar spaces. This study represents the first description of the pulmonary lesions caused by P. mexicanus in wild mammals.
La paragonimiasis constituye una enfermedad zoonótica con origen en México por el digeneo adulto Paragonimus mexicanus. El ciclo de vida de esta especie involucra dos hospederos intermediarios obligatorios: un caracol y un cangrejo, así como un mamífero que actúa como hospedero definitivo. La infección humana ocurre a través de la ingestión de carne de cangrejo cruda o insuficientemente cocida, parasitada por metacercarias. En marzo de 2005, seis tlacuaches (Didelphis virginiana) fueron capturados en Colima, México; fueron sacrificados con el fin de extraer los pulmones mediante necropsia para identificar las lesiones ocasionadas por el parásito. Los pulmones parasitados fueron procesados y teñidos de acuerdo con las técnicas histológicas convencionales. Cuatro de los seis (67%) hospederos resultaron infectados por 25 gusanos adultos identificados como P. mexicanus. En un pulmón se encontraron hasta 13 granulomas, distribuidos multifocalmente. Los principales cambios histológicos fueron: infiltración inflamatoria de monocitos, linfocitos, macrófagos, células plasmáticas, epitelioides y gigantes, con abundantes neutrófilos y eosinófilos, así como necrosis central del granuloma eosinofílico. Asimismo, se observó neumonía intersticial debido a la presencia de huevos entre las paredes del granuloma y los espacios alveolares. Este estudio representa la primera descripción de lesiones pulmonares ocasionadas por P. mexicanus en mamíferos silvestres.
ABSTRACT
Human gnathostomiasis is a food-born parasitic disease of relative importance in many countries in Southeast Asia. It is caused by several species of nematodes of the genus Gnathostoma. In Mexico is an emerging public health problem since 1970, when first cases were reported. Until today, larval morphometric characters that have been proposed to differentiate between the three species of Gnathostoma present in this country, are not satisfactory. Recently, the presence of advanced third-stage larvae AdvL3 (infective form for humans) in freshwater fishes from Pantanos de Centla, Tabasco. was recorded but their specific identity was not clarified . Examination of four species of freshwater fishes from the same locality revealed that three of them: Petenia splendida (n=58), Cichlasoma managuense (n=35) and Gobiomorus dormitor (n=9) were infected by 15 AdvL3 of Gnathostoma binucleatum. Specific identity was obtained comparing the internal transcribed spacer 2 (ITS2) of the ribosomal DNA with sequences reported in Genbank. This is the first record of G. binucleatum in P. splendida and G. dormitor from Tabasco and the first specific determination of the parasite in the locality.
Subject(s)
Animals , DNA, Ribosomal/analysis , DNA, Helminth/analysis , Gnathostoma/genetics , Fishes/parasitology , Molecular Sequence Data , Gnathostoma/classification , Gnathostoma/isolation & purification , Mexico , Base Sequence , Fresh WaterABSTRACT
The present study analyses the taxonomic status of eleven species of trichostrongylins that parasitize rodents and lagomorphs deposited in the Colección Nacional de Helmintos, Instituto de Biología. UNAM. Mexico. This analysis is based on the morphology of the synlophe, characteristic that had not been studied for most of these nematode species and at present, it has a very important taxonomic value. As a result of this study, the identity of five species is ratified (Trichostrongylus calcaratus, Obeliscoides cuniculi, Carolinensis huehuetlana. Stilestrongylus peromysci and Nippostrongylus brasiliensis), the transference suggested previously for two more (Vexillata convoluta and Vexillata vexillata) is confirmed, Trichostrongylus chiapensis is synonymized with Boehmiella willsoni, and finally Lamothiella romerolagi is re-determined as Teporingonema cerropeladoensis and Stilestrongylus atlatilpinensis as Stilestrongylus hidalguensis.
Subject(s)
Animals , Male , Female , Trichostrongyloidea/anatomy & histology , Trichostrongyloidea/classification , MexicoABSTRACT
In this work, we present an addendum to the "Checklist of the helminth parasites of vertebrates in Costa Rica" with a parasite-host list as well as a host-parasite list. This addendum updates the available information on this group of parasites in Costa Rica, since very recently a new input has been made to describe the helminth fauna of vertebrates, particularly at the Area de Conservación de Guanacaste. In this paper, we add 33 records, representing 23 species. This raises the number of helminth species described in vertebrates from Costa Rica to 325, represented by 89 species of digeneans, 23 of monogeneans. 63 of cestodes, 13 of acanthocephalans, and 137 of nematodes. In total, 133 species of vertebrates have been studied for helminths in Costa Rica (31 species of fishes. 7 amphibians, 18 reptiles, 40 birds, and 37 mammals). Currently, 67 species (20.6 %) have been recorded as new species from Costa Rica and most of them are endemic to particular regions. The Colecci6n de Helmintos de Costa Rica, housed at the Universidad de Costa Rica (UCR), San José, is the depositary of only 23% of the species recorded so far; however this situation is changing and people recognizes.
Subject(s)
Animals , Helminths/classification , Vertebrates/parasitology , Costa Rica , Vertebrates/classificationABSTRACT
Helminth parasites of vertebrates have been studied in Costa Rica for more than 50 years. Survey work on this group of parasites is far from complete. We assembled a database with all the records of helminth parasites of wild and domestic vertebrates in Costa Rica. Information was obtained from different sources such as literature search (all published accounts) and parasite collections. Here we present a checklist with a parasite-host list as well as a host-parasite list. Up to now, 303 species have been recorded, including 81 species of digeneans, 23 monogeneans, 63 cestodes, 12 acanthocephalans, and 124 nematodes. In total, 108 species of vertebrates have been studied for helminths in Costa Rica (31 species of fishes, 7 amphibians, 14 reptiles, 20 birds, and 36 mammals). This represents only 3.8% of the vertebrate fauna of Costa Rica since about 2,855 species of vertebrates occur in the country. Interestingly, 58 species (19.1%) were recorded as new species from Costa Rica and most of them are endemic to particular regions. Considering the valuable information that parasites provide because it is synergistic with all the information about the natural history of the hosts, helminth parasites of vertebrates in Costa Rica should be considered within any initiatives to accomplish the national inventory of biological resources. Starting with this compilation work, the Colección de Helmintos de Costa Rica (CHCR), hosted at the Facultad de Microbiología, Universidad de Costa Rica, has re-emerged and it is our hope that it will have the standards of quality to assure that it will become the national depository of helminths in the country.
Subject(s)
Animals , Helminths/classification , Vertebrates/parasitology , Costa Rica , Vertebrates/classificationABSTRACT
The helminth infracommunity structure was analyzed in 48 salamanders (Ambystoma lermaensis) from San Pedro Tlaltizapßn, Lerma, Estado de Mexico (June 1997 to March 1999). Richness (2.46 +/- 1.8), abundance (29.5 +/- 42.3), and diversity (0.64 +/- 0.58) levels characterize these communities as depauperate, similar to other amphibian helminth communities worldwide. Apparently, the main forces determining infracommunity structure are ectothermy (as regulator of the ingestion rate), and the opportunistic feeding habits of the hosts, because 80 of the helminth taxa enter the host by ingestion of intermediate hosts.
Subject(s)
Animals , Ambystoma , Helminths , Helminthiasis, Animal/parasitology , Mexico , Host-Parasite InteractionsABSTRACT
El registro helmintológico de las "sardinas" Harengula thrissina (N=61) y Opisthonema libertate (N=43)en la Bahía de Chamela, Jalisco, México, establecido en este trabajo, está integrado por 12 y seis especies, respectivamente. De éstas, la que alcanzó los valores más elevados de prevalencia y abundancia en O. libertate fue el nemátodo Pseudoterranova sp. (11.6% y 0.13 gusanos por pez revisado), mientras que para H. thrissina lo fue tremátodo Parahemiurus merus con 49.1% y 1.40 helmintos por hospedero muestreado. La reducida similitud cualitativa y cuantitativa registrada entre las helmintofaunas de ambos hospederos, se atribuye a la naturaleza oportunista de su alimentación (100% de las especies parásitas de H. thrissina y 66% de las de O. libertate las infectan a través de esta vía), así como a la exposición diferencial de ambas especies de hospederos a los helmintos.
Subject(s)
Animals , Fishes , Helminths , Seawater , Atlantic Ocean , Helminths , Mexico , Host-Parasite InteractionsABSTRACT
En el presente trabajo se realiza la revisión de la literatura relacionada con los céstodos, parásitos del hombre, poniéndose especial énfasis en las cestodiasis registradas en México; se señalan además, los principales rasgos morfológicos utilizados en su identificación, así como sus ciclos de vida, distribución y los aspectos clínicos más comunes que se presentan en estas parasitosis
Subject(s)
Humans , Cestoda/growth & development , Cestode Infections/epidemiology , MexicoABSTRACT
Se trataron huevos de Taenia saginata, T.hydatigena y T. pisiformis, con diferentes diluciones de los productos quimicos microdyn, elibac, nibac y trop-fen durante 24 horas, con objeto de determinar su accion ovicida. Se observo el efecto que estos agentes tienen sobre los huevos antes de someterlos a la digestion artificial para evaluar los posibles danos morfologicos, que no se encontraron.La presencia de oncosferas libres con citoplasma y forma normales, ademas de movimientos de los ganchos del embrion despues de la incubacion de los huevos con jugos gastricos e intestinales, fueron los criterios utilizados para determinar su vitalidad. El microdyn, elibac, nibac y trop-Fen no tuvieron actividad ovicida sobre los huevos de estos cestodos, aun utilizandolos puros durante 24 horas; es decir, 10,000 veces mas concentrados y exponiendolos un tiempo 100 veces mayor que lo indicado por los fabricantes