Aspectos morfológicos e moleculares de carrapatos do complexo Amblyomma maculatum

Abstract

The objective of the present study was to compare the morphological and molecular aspects of the tick populations of the Amblyomma maculatum complex of the State of Maranhão with those of different regions of Brazil stored in Coleção Nacional de Carrapatos of Universidade de São Paulo. Specimens were collected from the municipality of Bacurituba (02 ° 42 '21 "S 44 ° 44' 16" W) in the State of Maranhão and compared with specimens from the National Collection of Ticks of the Universidade de São Paulo. Maranhão ticks were collected from swine (Sus scrofa domesticus) raised in an extensive regime and transported to the Universidade de São Paulo. The ticks were stored in properly identified plastic pots and placed in a BOD incubator with 27 ˚C and 90% RH. After the ticks were hatched, the immature phases were placed for infestation in Cavia porcellus until the adult phases were reached, the study's target comparative. The specimens were identified by key and were measured using the Carl Zeiss Microscope model SteREO Discovery.V12 and its ZEN software to measure the variables: Thigh and Thigh I length (left and right), Thigh IV and Thorn IV (left And rights), Chapter Length and Width. DNA extraction for the molecular analyzes was performed according to the Guanidine Isothiocyanate (GT) protocol. Once the DNA was extracted, they were submitted to two polymerase chain reaction (PCR) protocols. Two markers were used to amplify approximately 460-bp fragments of the mitochondrial 16S rRNA and 1200-bp gene from the second internal transcript space (ITS2) of nuclear ribosomal DNA. The specimens of females and males were morphologically evaluated and identified as Amblyomma triste. Specimens from the National Collection of Ticks "Danilo Gonçalves Saraiva" were compared with the specimens of the present study. Statistical difference (P <0.05) was observed for the dimensions (Right thigh I / Right thigh I, Right thigh IV / Right thigh IV, Left thigh IV / Left thigh IV) Thigh Thighs I and Thigh IV. There was no statistical difference (P> 0.05) for the length of the Chapter Length by Chapter Width. For females, statistical difference was observed for right spur I, left thigh I, left spur I and section width. Sequences obtained when compared, according to the mitochondrial 16S rRNA gene and sequences derived from the nuclear ribosomal ITS2, it is observed that the specimens found in Maranhão have similarity to Amblyomma maculatum from the United States.