Two parasites in one host: spatiotemporal dynamics and co-occurrence of Microsporidia and Rickettsia in an amphipod host

Microsporidian diversity in the aquatic isopod Asellus aquaticus

We conducted a molecular survey on microsporidian diversity in different lineages (operational taxonomic units = OTUs) of Asellus aquaticus from 30 sites throughout Europe. Host body length was determined, and DNA was extracted from host tissue excluding the intestine and amplified by microsporidian-specific primers. In total, 247 A. aquaticus specimens were analysed from which 26.7% were PCR-positive for microsporidians, with significantly more infections in larger individuals. Prevalence ranged between 10 and 90%. At 9 sites, no microsporidians were detected. A significant relationship was found between the frequency of infected individuals and habitat type, as well as host OTU. The lowest proportion of infected individuals was detected in spring-habitats (8.7%, n = 46) and the highest in ponds (37.7%, n = 53). Proportion of infected individuals among host OTUs A, D and J was 31.7, 21.7 and 32.1%, respectively. No infections were detected in OTU F. Our results are, however, accompanied by a partially low sample size, as only a minimum of 5 individuals was available at a few locations. Overall, 17 different microsporidian molecular taxonomic units (MICMOTUs) were distinguished with 5 abundant isolates (found in 4–17 host individuals) while the remaining 12 MICMOTUs were “rare” and found only in 1–3 host individuals. No obvious spatio-genetic pattern could be observed. The MICMOTUs predominantly belonged to Nosematida and Enterocytozoonida. The present study shows that microsporidians in A. aquaticus are abundant and diverse but do not show obvious patterns related to host genetic lineages or geography.

Extremely divergent COI sequences within an amphipod species complex: A possible role for endosymbionts?

Some heritable endosymbionts can affect host mtDNA evolution in various ways. Amphipods host diverse endosymbionts, but whether their mtDNA has been influenced by these endosymbionts has yet to be considered. Here, we investigated the role of endosymbionts (microsporidians and Rickettsia) in explaining highly divergent COI sequences in Paracalliope fluviatilis species complex, the most common freshwater amphipods in New Zealand. We first contrasted phylogeographic patterns using COI, ITS, and 28S sequences. While molecular species delimitation methods based on 28S sequences supported 3-4 potential species (N, C, SA, and SB) among freshwater lineages, COI sequences supported 17-27 putative species reflecting high inter-population divergence. The deep divergence between NC and S lineages (~20%; 28S) and the substitution saturation on the 3rd codon position of COI detected even within one lineage (SA) indicate a very high level of morphological stasis. Interestingly, individuals infected and uninfected by Rickettsia comprised divergent COI lineages in one of four populations tested, suggesting a potential influence of endosymbionts in mtDNA patterns. We propose several plausible explanations for divergent COI lineages, although they would need further testing with multiple lines of evidence. Lastly, due to common morphological stasis and the presence of endosymbionts, phylogeographic patterns of amphipods based on mtDNA should be interpreted with caution.

Endoparasites Infecting Domestic Animals and Spectacled Bears (Tremarctos ornatus) in the Rural High Mountains of Colombia

Simple Summary

The spectacled bear (Tremarctos ornatus) is a threatened species, a member of the Ursidae family that lives in the Andes rural high mountain territories of Colombia, Venezuela, Ecuador, Peru, and Bolivia near livestock areas. Parasites in the spectacled bear are a relevant area of interest to preserve this species and understand its habitats and interactions with farm animals. The present work aimed to evaluate the presence of endoparasites in both T. ornatus and domestic animals in these areas, by copro- parasitological examination. The results indicate that some parasites have zoonotic potential in wild endangered species and domestic animals in Colombian regions. More sensitive molecular techniques are needed for further identification of the parasite species.

Abstract

This research described the co-infection prevalence of endoparasites in Tremartus ornatus and domestic animals in the rural high mountains of Colombia by copro-parasitological examination. Some parasites have a zoonotic potential in wild endangered species and domestic animals in Colombian regions. T. ornatus had a notable infection with Eimeria spp., Ascaris spp., Ancylostoma spp., and Baylisascaris spp. Cryptosporidium spp., Balantidium coli, Anoplocephala spp., and Acanthamoeba spp. In B. taurus, Eimeria spp. is coinfecting with Cryptosporidium spp. (6.6%) and represents 18% of the total parasitism. In E. caballus and B. taurus. Eimeria spp. coinfecting (34.7%), with the Strongylus spp. (21.9–25%). In T. ornatus, Eimeria spp. is coinfecting with Ancylostoma spp. (36.2%), Cryptosporidium spp., Ascaris spp., Baylisascaris spp., and B. coli.