Selective recovery of the cultivation-prone components from mixed trypanosomatid infections: a case of several novel species isolated from Neotropical Heteroptera

Abstract

Mixed trypanosomatid infections (a simultaneous presence of two or more parasites in the same host) have long been suspected to represent an obstacle for recovering cultures that would faithfully represent original species descriptions. However, without the means to directly compare the parasites in the host and in culture, this would remain just a possibility. Here we have used PCR-based genotyping of spliced leader RNA gene repeats to analyse several novel species of insect trypanosomatids isolated from heteropteran hosts and to compare them with the parasites that had been detected in the gut smears of the same hosts. We have found that, whereas the original infections were dominated by some blastocrithidia-like parasites, most of the respective axenic cultures contained novel species of Crithidia and Leptomonas. Therefore, we concluded that, in each case, this replacement was caused by differences in cultivation properties between the original predominant blastocrithidia and the less fastidious parasite that was later recovered in culture. The properties of the new organisms, including their morphology and ultrastructure, as well as their phylogenetic affinities within the family, were investigated and used to describe five novel species.

Probing into the diversity of trypanosomatid flagellates parasitizing insect hosts in South-West China reveals both endemism and global dispersal

“…One host species, in some cases one particular individual, may be infected with several distantly related parasites, as exemplified in this study by the one specimen of Aquarius p. paludum (Gerridae) found to harbor three species of trypanosomatids (Ch2, Ch7 and Ch15). With this, and our earlier findings (Maslov et al, 2007;Yurchenko et al, 2009), mixed infections of a single host with several species of trypanosomatids appear almost a rule, rather than exception, particularly in predatory species. The remaining cases in which a single parasite species was found per one host species cannot be taken as an evidence of strongly specific associations due to a limited sampling size.…”

“…To this end, we selected a single member of each typing unit (Table 2) to amplify these genes directly from the infected gut DNA samples using trypanosomatidspecific primers (Maslov et al, 1996). Caution was taken to avoid those samples that contained more than a single trypanosomatid type (Yurchenko et al, 2009).…”

High prevalence of trypanosome co-infections in freshwater fishes

“…While we believe that the morphology of the Trypanosomatidae should not be used as a sole taxonomical feature (Yurchenko et al 2006b, 2008, 2009, Votýpka et al 2010, to comply with established practices, here we present a brief morphological description of the most prevalent morphotypes detected in different fish species. Detailed size characteristics are provided in Table 2.…”

Spliced Leader (SL) RNA: análises de genes e regiões intergênicas com aportes na filogenia, taxonomia e genotipagem de <i>Trypanosoma</i> spp. de todas as classes de vertebrados.

“…Abordagens baseadas no SL têm sido avaliadas em uma série de estudos que analisam a diversidade e as relações hospedeiro-parasito de tripanossomatídeos de insetos Heteroptera (Maslov et al, 2007(Maslov et al, , 2013Yurchenko et al, 2009;Votypka et al, 2010Votypka et al, , 2012 e Diptera (Tyc et al, 2013).…”

“…Igualmente, este marcador tem sido utilizado para determinar TUs para identificar novas espécies potenciais de tripanossomatídeos (Maslov et al, 2007(Maslov et al, , 2013Yurchenko et al, 2009;Votypka et al, 2010Votypka et al, , 2012, assim como para confirmar as espécies novas de Trypanosoma (Lima et al, 2013(Lima et al, , 2015a.…”