Comparative study of the biological behaviour in hamster of two isolates of leishmania characterized respectively as L. major-like and L. donovani

Abstract

SUMMARYHamster inoculate d intraperitoneall y wit h 1 x 10 7 parasites o f L. donovani an d L. major -like o f th e Ne w Worl d wer e studie d i n group s o f 15 , 30 , 6 0 an d 9 0 day s of infection . Th e parasit e loa d an d densit y showe d progressiv e increas e wit h th e evolution o f th e infectio n an d wa s highe r i n th e L . donovan i group s tha n i n th e L. major -like groups . Th e L . major -like group s showe d parasit e densit y highe r i n the splee n tha n i n th e live r an d wa s simila r i n bot h organ s i n L . donovan i groups . The histopatholog y showe d a diffus e marke d hyperplasi a an d hypertroph y o f th e reticuloendothelial syste m wit h hig h parasitis m i n th e L . donovan i group s whil e there was focal involvement o f these organs in L. major-like groups , forming nodule s of macrophages tha t wer e scantl y parasitised .The biological behaviour coul d be useful in the preliminary studie s of Leishmania strain i n regiona l laboratorie s an d understanding th e histopatholog y o f lesions caused by differen t leishmania species.

Therapeutic effect of ursolic acid in experimental visceral leishmaniasis

“…Before treatment, a few hamsters were euthanized in order to verify the presence of parasites in spleen and liver. Animals showed high parasitism and the organs presented macro- and microscopic alterations, as previously reported by our group (Duarte et al., 1988, Laurenti et al., 1990, Laurenti et al., 1996, Corbett et al., 1992, Corbett and Laurenti, 1998). UA was solubilized in DMSO and further PBS (never exceeding 1% DMSO); and amphotericin B was solubilized in sterile water for injection plus 1% DMSO.…”

Hepatic extracellular matrix in BALB/c mice infected with Leishmania donovani

“…histopathological changes characterized by hyperplasia and hypertrophy of the Kupffer cells with discrete parasitism (Wilson et al, 1987, Duarte et al, 1988. In the late stages of infection there was was also an increase in hyperplasia and hypertrophy and parasitism similar to the lesions observed in human infections by Duarte and Corbett (1987) and Corbett et al (1993).…”

Reproduction of Leishmania (Leishmania ) infantum chagasi in conditioned cell culture growth medium

“…Additionally, isolation of the leishmania can be obtained together with an increase in their density within a shorter time, as may be seen in the growth kinetics (Fig. 2), especially when compared with the method of isolation in laboratory rodents which takes about six months to achieve a critical mass of leishmanias (in amastigote form) 9 , so as to permit their isolation in NNN or RPMI medium and thus obtain the flagellate form (promastigote).…”

“…The parasitologic laboratory test that identifies the parasite in aspirates (whether from bone marrow, lymph node, blood or skin specimens) is not always practicable, because it requires a specialized technical team and resources that are not everywhere available. Similarly, isolation of Leishmania (Leishmania) infantum chagasi using laboratory animals, such as hamsters 9 , is a very slow and costly method. Several techniques have been described to obtain isolations in vitro, including: cultivation on semi-solid Novy-McNeal-Nicolle medium (NNN) 15 , on RPMI-1640 medium 13 or on Schneider medium enriched with urine 14 , but all fail to perpetuate leishmanias after several passages, thereby limiting large-scale production.…”