Effects of experimental infections with larvae of Eustrongylides ignotus Jäegerskiold, 1909 and Contracaecum multipapillatum (Drasche, 1882) Baylis, 1920 in rabbits

Abstract

Rabbits were infected per os with 10 Eustrongylides ignotus L4 and with 50 Contracaecum multipapillatum L3 per rabbit, recovered from naturally infected freshwater fishes (Hoplias malabaricus) in order to evaluate the patogenicity of these two nematode species in mammalian host. Two rabbits (20%) infected with E. ignotus died before the fourth day post-inoculation (one after 51 and the other after 78 hours). Six rabbits (60%) were inappetent until the fifth day following experimental inoculation. No clinical signs in rabbits inoculated with C. multipapillatum were observed; nevertheless, eight (80%) animals were positive for this nematode species. Rabbits inoculated with E. ignotus, had gastric congestion with hematoma of the gastric wall in 60% of the cases. Peritoneum was congested in 20% of the animals with the presence of peritoneal abscess in 10% of the cases. All inoculated animals showed hyperemia of the gastric mucosa with hemorrhagic gastritis due to infections with E. ignotus. In C. multipapillatum inoculated animals, the hyperemia was followed by disruption of the epithelial mucosa in the sites of parasite attachment. In the gastric mucosa, miscellaneous leukocitary infiltrates, with multifocal necrosis reaching the submucosa in the infections with C. multipapillatum were observed under bright field microscopy. Perforating lesions in several organs, mainly in the gastric wall, pancreas and liver, always in the presence of a mixed inflammatory process, intensely fibrous, with hemorrhage and necrosis were observed in animals infected with E. ignotus.

Nematodes in Hoplerytrinus unitaeniatus, Hoplias malabaricus and Pygocentrus nattereri (pisces characiformes) in Marajó Island, Brazil

“…Infections with the species A. simplex (Rudolphi, 1809) and P. decipiens (Krabbe, 1878) are the most important occurrences, according to Ishikura et al (1993) and Adams et al (1997). Contracaecum larvae mostly occur in the visceral organs and mesentery of fish, thus limiting their zoonotic threat, which may explain why human cases are rare even considering that mammals are susceptible to experimental infection with these larvae (VIDAL-MARTINEZ et al 1994;BARROS et al, 2004).…”

Prevalence for nematodes of hygiene-sanitary importance in fish from Colares Island and Vigia, Pará, Brasil

“…To evaluate zoonotic potential of Contracaecum, mammals were experimentally infected, resulting in damage to organism, which highlighted the zoonotic importance of this genus that belongs to Anisakidae family (Vidal-Martinez et al, 1994;Barros et al, 2004). Human infection by Eustrongylides sp.…”

Primeiro relato de larvas de Eustrongylides sp. (Nematoda: Dioctophymatidae) em Hoplias malabaricus (Characiformes: Erythrinidae) no Estado de Rondônia, Amazônia Ocidental, Brasil

“…Eustrongylides sp. são nematoides encontrados em sua fase larval em algumas espécies de peixes carnívoros, como Auchenipterus nigripinnis, Brycon 10,11 .…”