Non-Strongyloides rhabditida identified in fecal samples – two case reports: lessons learned from morphological and molecular diagnostic approaches

Abstract

Nematodes in the order Rhabditida, including species of Strongyloides and Pelodera, may be parasites of domestic animals. In this paper, we describe two apparent cases of rhabditid infections, one in a dog and one in a litter of piglets. The dog infection was originally considered likely to be an infection with Strongyloides, based on superficial morphological examination and PCR results without sequencing. However, more careful morphological analysis and inclusion of several molecular analyses, including sequencing, revealed that an infection with Pelodera sp. was more likely, probably Pelodera pseudoteres. Treatment with fenbendazole and selamectin was apparently successful. Similarly, based on both morphological and molecular analyses the apparent piglet infections were considered most likely to be with Rhabditis spp., possibly Rhabditis axei. The detection of larvae of nematodes in the order Rhabditida in fecal samples, particularly from dogs, may easily be considered as being indicative of Strongyloides infection. Given the zoonotic potential of canine Strongyloides, correct diagnosis is important. However, as illustrated by these two cases, careful morphological examination and measurement, supported by full molecular investigations, including sequencing, are essential in order to avoid this misdiagnosis.

Intraspecific Morphological Variation in Free-Living Stages of Strongyloides Papillosus (Nematoda, Strongyloididae) Parasitizing Various Mammal Species

“…Th e high extent of infestation oft en leads not only to decrease in the effi ciency, and to susceptibility to other diseases, but also to the death of animals at an early age (Taira & Ura, 1991). Th erefore, livestock farms suff er signifi cant economic losses (Peter et al, 2015;Stachurska-Hagen et al, 2016;Th amsborg et al, 2017;Boyko & Brygadyrenko 2017. Data on the peculiarities of distribution, intensity of infestation, severity of the helminthiasis in cases of parasitization by S. papillosus in diff erent species of hosts in relation to their age, geographical distribution, season and many other factors, as well as the morphometric features of nematodes of this genus are provided in a number of publications (Singh et al, 1997;Bekele, 2002;Agyei, 2003;Eysker et al, 2005;Jäger et al, 2005;.…”

Strongyloidiasis in northern Vietnam: epidemiology, clinical characteristics and molecular diagnosis of the causal agent

“…Thus, ITS1 becomes more appropriate for interspecific differentiation, which in the case of Strongyloides spp. infection in humans becomes important due to the existence of another Strongyloides species able to infect humans, S. fuelleborni [45, 47, 50] or even non- Strongyloides rhabditids which may appear in human stools [51].…”

Nematocidial activity of aqueous solutions of plants of the families Cupressaceae, Rosaceae, Asteraceae, Fabaceae, Cannabaceae and Apiaceae

“…Rhabditida pathogens of nematodiases in mammals are most often represented by Strongyloides papillosus (Wedl, 1856). Helminthiases cause economic losses to livestock farms every year (Peter et al, 2015;Stachurska-Hagen et al, 2016;Thamsborg et al, 2017;Zazharska et al, 2018). S. papillosus is a nematode which affects the gastrointestinal tract and breathing organs (at the larva stage).…”