A comprehensive analysis of viability assessment methods for Giardia lamblia and Trichomonas vaginalis: a systematic review

Abstract

Abstract Giardia lamblia (G. lamblia) and Trichomonas vaginalis (T. vaginalis) are flagellated protozoan parasites. These pathogenic agents commonly cause asymptomatic infections; however, they may lead to gastrointestinal or genitourinary symptoms. The primary pharmacological treatment for both conditions is metronidazole, although it has been reported to have some limitations. Despite the pressing need for improved treatment options, the choice of an appropriate method for assessing the in vitro viability of G. lamblia and T. vaginalis in the presence of therapeutic compounds remains a challenge due to the variability in these methods. This study aims to provide a comprehensive overview of commonly employed methods for determining trophozoite viability in the presence of potential therapeutic compounds. The present systematic review resulted from a literature search conducted in PubMed, ScienceDirect, and Web of Science with the following search equation: “in vitro“ AND "method“ AND ("susceptibility“ OR "viability“ OR "sensitivity“) AND ("giardia" OR "trichomonas“). The search identified 29 experimental studies with diverse viability assays. The cell counting method was the only common viability assay between both parasites that was most frequently cited. For G. lamblia, the adherence inhibition assay and [3H]-thymidine assay were prominent. In T. vaginalis, the trypan blue assay, motility assessment, and the resazurin assay were frequently cited. The selection of an appropriate method is vital for accurate and reproducible results. Further research and standardization of viability assessment methods are imperative to enhance the understanding of drug susceptibility and develop effective treatment strategies for parasitic infections.