Isolado de Lagochilascaris minor: procedimentos para obtenção de ovos infectantes / Lagochilascaris minor isolate: a procedure for obtaining infecting egs

Lagochilascaris minor tem sido mantido no Departamento de Parasitologia da Universidade Federal de Goiás, desde 1989, utilizando-se o modelo experimental: camundongo e gato doméstico. No início destes estudos, ovos infectantes do parasito eram obtidos por dissecação de alças uterinas de fêmeas de L. minor recuperadas de lesões cervicais humanas. Posteriormente observou-se que em gatos infectados experimentalmente os parasitos localizam-se, preferencialmente, em tecidos da rino e orofaringe. Nestes tecidos, vermes são encontrados no interior de tumorações que se fistulam para a luz do tubo digestivo liberando grande quantidade de ovos nas fezes destes animais. Visando otimizar a obtenção de ovos eliminados pelas fêmeas de L. minor, propôs-se o emprego do método de sedimentação espontânea acrescido do método de centrífugo-flutuação em sulfato de zinco (Faust e cols.) em fezes de gatos infectados. A utilização deste métodos permitiu obter ovos larvados, viáveis, livres de detritos fecais e em maior proporção do que por dissecação de alças uterinas do verme.

Wild Rodents as Experimental Intermediate Hosts of Lagochilascaris minor Leiper, 1909

A total of 25 specimens of Cavia porcellus (guinea pig), 5 Dasyprocta agouti (agouti), and 22 Calomys callosus (vesper mice) were inoculated with infective eggs of Lagochilascaris minor. The inoculum was prepared with embryonated eggs and orally administered to each individual animal through an esophagus probe. In parallel, 100 specimens of Felis catus domesticus were individually fed with 55-70 nodules containing 3rd-stage larvae encysted in tissues of infected rodents. Animals were examined and necropsied at different time intervals. The migration and encystment of L3 larva was observed in viscera, skeletal muscle, adipose and subcutaneous tissues from all rodents. Adult worms localized at abscesses in the cervical region, rhino, and oropharynx were recovered from domestic cats inoculated with infected rodent tissues. Through this study we can conclude that: (1) wild rodents act as intermediate hosts, characterizing this ascarid heteroxenic cycle; (2) in natural conditions rodents could possibly act as either intermediate hosts or paratenic hosts of Lagochilascaris minor; (3) despite the occurrence of an auto-infecting cycle, in prime-infection of felines (definite hosts) the cycle is only completed when intermediate hosts are provided; and (4) in the wild, rodents could serve as a source of infection for humans as they are frequently used as food in regions with the highest incidence of human lagochilascariasis

Logochicaris inor Leiper, 1909: nove décadas de revisäo bibliográfica / Logochilascaris minor Leiper, 1909: nine decades of literature review

A lagochilascariose é uma infecçäo causada por vermes do gênero Lagochilascaris. A doença humana é restrita ao continente americano e tem sido associada a Lagochilascaris minor. É considerada uma helmintíase emergente e o Brasil lidera a casuística mundial com aproximadamente 90(por cento) dos casos descritos na literatura mundial. Esta revisäo tem como objetivo divulgar informaçöes sobre a lagochilascariose desde a época em que foi descrita até os dias atuais

Ocorrência de Lymnaea columella (Say, 1817)(Mollusca, Pulmonata, Lymnaeidae), no Estado de Goiás. Consideraçöes sobre os parasitos por ela transmitidos / Occurrence of Lymnaea columella (Say, 1817)(Mollusca, Pulmonata, Lymnaeidae) in the State of Goiás and commentes about the ralationships of the molluc with the transmission of some parasites

Os autores relatam a primeira ocorrência de Lymnaea columella (Say, 1817) no Estado de Goiás, ressaltando a importância da espécie como hospedeiro intermediário de vários parasitos dos animais domésticos, dos quais, alguns são agentes de zoonoses no Brasil e em outros países. Também fazem considerações sobre os parasitos transmitidos ou possivelmente transmitidos por este molusco, já assinalados no Brasil

Experimental life cycle of Lagochilascaris minor Leiper, 1909

The life cycle of Lagochilascaris minor was studied using material collected from human lesion and applying the experimental model: rodents (mice, hamsters), and carnivores (cats, dogs). In mice given infective eggs, orally, hatch of the third stage larvae was noted in the gut wall, with migration to liver, lungs, skeletal musculature and subcutaneous tissue becoming, soon after, encysted. In cats infected with skinned carcasses of mice (60 to 235 days of infection) it was observed: hatch of third stage larvae from the nodules (cysts) in the stomach, migration through the oesophagus, pharynx, trachea, related tissues (rhino-oropharynx), and cervical lymph nodes developing to the mature stage in any of these sites on days 9-20 post inoculation (P.I.). There was no parasite development up to the mature stage in cats inoculated orally with infective eggs, which indicates that the life cycle of this parasite includes an obligatory intermediate host. In one of the cats (fed carcass of infected mice) necropsied on day 43 P.I., it was observed the occurrence of the self-infective cycle of L. minor in the lung tissues and in the cervical region which was characterized by the finding of eggs in different stages of development, third stage larvae and mature worms. It's believed that some component of the carnivore gastrointestinal tracts may preclude the development of third stage larvae from L. minor eggs what explains the interruption of the life cycle in animals fed infective eggs. It's also pointed out the role of the intermediate host in the first stages of the life cycle of this helminth