EFFECT OF Bifidobacterium animalis ON MICE INFECTED WITH Strongyloides venezuelensis / Efeito da administração de Bifidobacterium animalis sobre a infecção por Stongyloides venezuelensis em camundongos

The administration of viable Bifidobacterium animalis was tested to induce resistance against Strongyloides venezuelensis infection in mice. Effects on parasite burden, worm length, egg output, and intestinal mucosal histology were evaluated. The oral administration of B. animalis, strain 04450B, starting 14 days before the inoculation of nematode larvae significantly decreased the worm burden and egg output. In probiotic treated animals, the percent reduction of adult worms in the intestine was of 33% and the reduction of egg production was of 21%, compared with those of the control group. The duodenum villous height and villous/crypt ratio were significantly higher in probiotic-treated mice, indicating that this group could be experiencing less intestinal damage. The present findings revealed that the administration of B. animalis for the amelioration of host response to nematode infections is biologically plausible and could have some potential for impacting public health. Meanwhile, further study is needed to delineate the nature and identity of the factor(s) involved in these beneficial effects.

Os efeitos da administração de Bifidobacterium animalis viáveis sobre a infecção por Strongyloides venezuelensis foram avaliados em camundongos experimentalmente infectados. Os parâmetros analisados incluíram a carga parasitária, o comprimento dos vermes, a quantidade de ovos eliminados e a histologia da mucosa intestinal. A administração oral da cepa 04450B de B. animalis, iniciada 14 dias antes da inoculação de larvas do nematódeo, foi acompanhada de uma redução significativa do número de vermes que se estabeleceu no intestino e do número de ovos eliminados nas fezes. Nos animais tratados com o probiótico, o percentual de redução de vermes adultos no intestino foi de 33% e da produção de ovos foi de 21%, em comparação com os do grupo controle. O comprimento das vilosidades do duodeno e a relação vilus/cripta foram significativamente maiores nos animais tratados, indicando que nestes animais as lesões intestinais foram mais leves. Os resultados do presente trabalho revelaram que a administração de B. animalis com o propósito de modular a resposta do hospedeiro contra infecções por nematódeos é uma possibilidade biologicamente plausível com impacto potencial em saúde pública. No entanto, são ainda necessários mais estudos para esclarecer os mecanismos de ação destes microrganismos e identificar os fatores envolvidos na produção dos efeitos benéficos.

A case of fatal hyperinfective strongyloidiasis with discovery of autoinfective filariform larvae in sputum

The autoinfective filariform larva of Strongyloides stercoralis causes hyperinfection in immunosuppressed hosts. Here we report on the case of a male patient who was admitted to the emergency room at Gwangju Veterans Hospital with a complaint of dyspnea, and who was receiving corticosteroid therapy for asthma. Many slender larvae of S. stercoralis with a notched tail were detected in Papanicolaou stained sputum. They measured 269 +/- 21.2 micrometer in length and 11 +/- 0.6 micrometer in width. The esophagus extended nearly half of the body length. The larvae were identified putatively as autoinfective third-stage filariform larvae, and their presence was fatal. The autoinfective filariform larva of S. stercoralis has not been previously reported in Korea.

Viability of Bovine`s Strongyloidea eggs in a System of Anaerobic Biodigestion

Cattle Strongyloidea egg-viability was studied in closed system of anaerobic biodigestion. Two thirds of a biodigestor were filled with liquified manure from eight Hosltein cows, nacturally infected. For 10 consecutive weeks of observation, the biodigestor internal temperature varied from 24ºC to 28ºC and external temperature, from 26ºC to 33ºC. All the effluent samples showed a constant pH of 7. The samples of the effluent were weekly collected, in a total of 10, and submitted to techniques to detect the presence and viability of the helminth eggs. It was detected a 35-day egg viability. The infective larvae of Haemonchus, Cooperia and Oesophagostomum genus were found until the 14th day of observation and the infective larvae of Trichostrongylus and Ostertagia genus, until the 35th day. Therefore, liquefied cattle manure containing Strongyloidea eggs must remain under anaerobic conditions for at least 35 days before its safe return to the environment.

Persistent infection with Strongyloides venezuelensis in the Mongolian gerbil (Meriones unguiculatus)

To examine the fate of Strongyloides venezuelensis. Mongolian gerbils (Meriones unguicalatus) were orally infected with 1,000 L3 larvae per animal. Altogether, 50 gerbils divided into 5 groups of 10 each were monitored for a period of 570 days to document the kinetics of faecal egg output, adults worm population, morphological development, fecundity, and hematological changes including peripheral blood eosinophilia. This study chronicled a life long parasitism of S. venezuelensis in the gerbil host, and showed that S. venezuelensis infection was quite stable throughout the course of infection and the worms maintained their normal development as evidenced by their body dimension. A progressive loss of body condition of the infected gerbils was observed as the level of infection advanced. However, no detectable pathological changes were observed in the gastrointestinal tract. The present findings indicate that an immunocompetent host, such as the Mongolian gerbil, can serve as a life long carrier model of S. venezuelensis if the worms are not expelled within 570 days after infection.

Strongyloides ratti and S. stercoralis: effects of Cambendazole, Thiabendazole and Mebendazole in vitro

Os efeitos da incubaçäo de três antihelmínticos, tiabendazol, mebendazol e cambendazol sobre Strongyloides foram comparados. Nenhuma droga afetou a eclosäo dos ovos de S. ratti ou a viabilidade de larvas infectantes ou vermes adultos parasitários, mas todas as três inibiram a formaçäo de larvas de S. ratti. Além disso, cambendazol, mas näo tiabendazol ou mebendazol, diminuiu a viabilidade de larvas de primeiro e segundo estágio de S. ratti. As três drogas näo tiveram efeito sobre vermes adultos de vida livre isolados, de S. stercoralis, mas todas evitaram o desenvolvimento de larvas rabditiformes de S. stercoralis. Tianbendazol e mebendazol näo tiveram efeito sobre a infectividade de larvas infectantes de S. ratti ou de S. stercoralis, mas a infecçäo com esses vermes foi anulada por incubaçäo prévia com cambendazol. Esses resultados indicam que cambendazol age de modo diferente das outras duas drogas. Uma vez que ele é ativo contra larvas migrando através dos tecidos, é potencialmente de muito maior valor que a tiabendazol ou mebendazol na terapêutica da estrongilodíase