Evaluation of five parasitological techniques for diagnosing phylum Ciliophora cysts in fecal samples from free-living wild artiodactyls

Avaliação de cinco técnicas parasitológicas para o diagnóstico de cistos do filo Ciliophora em amostras fecais de artiodáctilos silvestres em vida livre

ABSTRACT:

A variety of laboratory techniques are used in parasitological diagnosis. However, studies that analyze their laboratory efficiency are very scarce, especially with regard to biological samples from wild animals that are little known, with little popular attachment, such as artiodactyls. These can be infected by different parasites, including protozoa of the phylum Ciliophora, which includes the parasites Balantioides coli and Buxtonella sulcata. In this light, the aim of this study was to compare the efficiency of five coproparasitological techniques for diagnosing protozoan cysts of the phylum Ciliophora in the feces of free-living artiodactyls. To this end, 101 fecal samples were collected from trails in Pedra Selada State Park, Rio de Janeiro state, from 2020 to 2021. All the samples were analyzed using the qualitative techniques of modified Sheather floatation, modified Ritchie sedimentation and Lutz, as well as the quantitative techniques of Mini-FLOTAC and McMaster. Cyst recovery was best achieved using the modified Ritchie technique, in which 62.5% positivity was detected, followed by Lutz (47.5%), modified Sheather (37.5%) and the quantitative techniques of Mini-FLOTAC (30%) and McMaster (17.5%). In most of the comparisons between the techniques, reasonable agreement regarding the diagnosis was observed (Kappa 0.21 to 0.40), which was statistically significant (p≤0.05). McMaster showed higher mean and standard deviation values for counts of cysts per gram of feces than Mini-FLOTAC. However, there was no significant difference in the estimates for cyst counts (Wilcoxon p>0.05). Sedimentation qualitative techniques were more indicated for diagnosing cysts of protozoa of the phylum Ciliophora in the feces of free-living wild artiodactyls. These techniques can therefore be used as laboratory tools for environmental parasite monitoring. In addition, between the two quantitative techniques, Mini-FLOTAC presented better performance, thus showing its potential as a tool for estimating the abundance of cystic forms of the phylum Ciliophora in environmental samples.

INDEX TERMS:
Parasitological diagnosis; cyst; phylum Ciliophora; wild animals