Accumulation and distribution of lead in the archiacanthocephalan Moniliformis moniliformis from experimentally infected rats

Abstract

It recently became clear that adult eo- and palaeacanthocephalans parasitizing fish can bioconcentrate several heavy metals to significantly higher concentrations than the tissues of their definitive hosts. Following this discovery the lead accumulation of the archiacanthocephalan Moniliformis moniliformis was investigated using experimentally infected male Wistar rats of the CD-M-strain. The worms were allowed to grow up for 4 weeks post-infection followed by a 3 weeks oral lead exposure of the rats. After the exposure period the rats were killed and the metal levels were determined in muscle, liver, intestine and kidney of the rats as well as in different organs of female and male acanthocephalans. Lead concentrations were found to be highest in female M. moniliformis followed by the kidneys of the rats. Male worms contained approximately the same lead concentration as the hosts' kidneys. Lead analysis of the worms' organs revealed the highest lead concentration in the eggs of female acanthocephalans, followed by the cement gland of male Worms. Whilst the lead burden of the presoma was higher than that detected in the kidneys of the rats, the lead content of the metasoma was even lower than in the kidneys. A lead uptake of M. moniliformis from the intestinal lumen of the host became apparent as the faeces of infected rats contained significantly less lead compared to the uninfected conspecifics. Thus, this study reveals that lead accumulation also occurs in archiacanthocephalans parasitizing mammals. But the degree of metal bioconcentration is considerably lower compared to eo- and palaeacanthocephalans in fish. Anyway, due to a lack of adequate sentinel species in terrestrial biotopes the host-parasite system rat M. moniliformis appears to be a useful and promising bioindication system especially in urban ecosystems in temperate regions.

Cadmium and lead concentrations in Moniliformis moniliformis (Acanthocephala) and Rodentolepis microstoma (Cestoda), and in their definitive hosts, Rattus rattus and Mus domesticus in El Hierro (Canary Archipelago, Spain)

“…In our study, the bioaccumulation factors obtained for R. rattus/M. moniliformis are in line with those obtained experimentally by Sures et al (2000b), thus supporting the suitability of this system as a useful and promising tool in environmental monitoring.…”

Cadmium and lead concentrations in Gallegoides arfaai (Cestoda: Anoplocephalidae) and Apodemus sylvaticus (Rodentia: Muridae) from Spain

“…The scarce information available on terrestrial habitats contributes to the increasing need for further studies on sentinel organisms reflecting small-scale differences in heavy metal pollution in terrestrial ecosystems. In this context, two acanthocephalans, Macracanthorhynchus hirudinaceus from naturally infected pigs in Bolivia (Sures et al 2000a) and Moniliformis moniliformis parasitizing rats in experimental conditions (Scheef et al 2000;Sures et al 2000b), were shown to be important accumulation indicators of some heavy metals (cadmium and lead). Nevertheless, neither acanthocephalan should be considered a good sentinel due to the restricted range of the definitive hosts of M. hirudinaceus and because of the low abundance of M. moniliformis in naturally infected rats.…”

Experimental studies on the lead accumulation in the cestode Moniezia expansa (Cestoda: Anoplocephalidae) and its final host (Ovis aries)

“…In the study it was conclusively shown that infection of chub (Leuciscus cephalus) with Pomphorhynchus laevis resulted in significantly lower lead concentrations in the intestine of infected fish compared to uninfected controls. On the other hand, in an experimental study on the lead uptake by Moniliformis moniliformis no reduction of the lead concentration in the kidneys of the rat was observed (Sures et al 2000b).…”