Mucha Ayuda

The Journal of Venomous Animals and Toxins including Tropical Diseases ISSN 1678-9199 | 2011 | volume 17 | issue 3 | pages 239-248

Molecular techniques for the study and diagnosis of parasite infection
R eview A R ticle

Tavares RG (1, 2), Staggemeier R (3), Borges ALP (3), Rodrigues MT (3), Castelan LA (3), Vasconcelos J (3), Anschau ME (3), Spalding SM (4)

(1) Institute of HealthSciences, Biomedicine, Feevale University, Novo Hamburgo, Rio Grande do Sul State, Brazil; (2) Department of Diagnostic Methods, Federal University of Health Sciences of Porto Alegre, Porto Alegre, Rio Grande do Sul State, Brazil; (3) Graduate Program in Clinical Microbiology, Feevale University, Novo Hamburgo, Rio Grande do Sul State, Brazil; (4) Department of Parasitology, Federal University of RioGrande do Sul, Porto Alegre, Rio Grande do Sul State, Brazil.

Abstract: In parasitology, routine laboratory diagnosis involves conventional methods, such as optical microscopy, used for the morphological identification of parasites. Currently, molecular biology techniques are increasingly used to diagnose parasite structures in order to enhance the identification and characterization ofparasites. The objective of the present study was to review the main current and new diagnostic techniques for confirmation of parasite infections, namely: polymerase chain reaction (PCR), real-time polymerase chain reaction (RT-PCR), loop-mediated isothermal amplification (LAMP), Luminex xMAP, random amplified polymorphic DNA (RAPD), amplified fragment length polymorphism (AFLP), and restriction fragmentlength polymorphism (RFLP), in addition to microsatellites. Molecular assays have comprehensively assisted in the diagnosis, treatment and epidemiological studies of parasitic diseases that affect people worldwide, helping to control parasitic disease mortality. Key words: parasite infection, diagnosis, molecular techniques, molecular epidemiology.

INTRODUCTION In parasitology, routinelaboratory diagnosis involves conventional methods, such as optical microscopy, used for the morphological identification of parasites (1). However, the occasional difficulty of identifying these parasite structures may decrease the sensitivity of such methods. Currently, because of these difficulties, molecular biology has been employed to detect parasites responsible for parasitic diseases (2).Traditional parasitological analyses have the advantage of being less costly without requiring expensive reagents and equipment. Additionally, such analyses can be easily performed when a trained microscopist is available. On the other hand, molecular technology demonstrates the presence of parasites based on their antigenic components or DNA segments (3). These tests

are not influenced byenvironmental factors that usually can interfere with the results of a stool test, for example, thus ensuring highly reliable results (4). Current laboratory diagnostic methods for the identification of parasites include: polymerase chain reaction (PCR), random amplified polymorphic DNA (RAPD), amplified fragment length polymorphism (AFLP), restriction fragment length polymorphism (RFLP), microsatellitemarker method, Luminex xMAP-based technology (areas of multianalyte profiling), loop-mediated isothermal amplification (LAMP), and the recently added real-time PCR (5-12). The objective of the present article was to review the applications of molecular biology techniques in parasitology by evaluating and discussing their uses and benefits.

Tavares RG, et al. Molecular techniques for the study anddiagnosis of parasite infection

MOLECULAR METHODS FOR DETECTION OF PARASITE STRUCTURES Several molecular tests to detect parasites have been developed in the last decade. Their specificity and sensitivity have gradually increased, and parasites that were previously difficult to diagnose using conventional techniques began to be identified by molecular techniques. As a result, currently, these...