Detection of natural infection of Boophilus microplus with Babesia equi and Babesia caballi in Brazilian horses using nested polymerase chain reaction.
The potential role of Boophilus microplus as a natural tick vector of Babesia equi and Babesia caballi in Brazilian horses was assessed using nested polymerase chain reaction (PCR)-based marker assay. B. equi merozoite-specific 218bp gene fragment was detected in almost 96% of horse blood samples, and 45.3-62.5% of females, eggs, larvae, and nymphs of B. microplus collected from 47 horses at Campo Grande in the State of Matto Grosso, Brazil. Except for the partially-fed female ticks, the B. caballi-specific 430bp gene fragment was amplified from horse blood samples, and all developmental stages. Parasite DNA from both species was detected in horse blood samples and B. microplus, with the preponderance of B. equi DNA. No DNA samples were positive solely for B. caballi parasite. Only 32% of the Giemsa-stained thin blood smears were positive for Babesia parasites, as against detection of B. equi parasite DNA in 95.7% of the blood samples by nested PCR. We have obtained molecular evidence that strengthens earlier experimental and ultrastructural studies in Brazil incriminating B. microplus as a natural vector of B. equi, and possibly of B. caballi. The detection of B. equi and B. caballi DNA in eggs and larvae of B. microplus is likewise suggestive of the possibility of both transovarial and transstadial parasite transmission in this tick vector.
Battsetseg
Badgar
B
Department of Basic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, Yanagito, Japan.
Lucero
Susana
S
Xuan
Xuenan
X
Claveria
Florencia G
FG
Inoue
Noboru
N
Alhassan
Andy
A
Kanno
Tsutomo
T
Igarashi
Ikuo
I
Nagasawa
Hideyuki
H
Mikami
Takeshi
T
Fujisaki
Kozo
K
D000818:Animals; D001096:Arachnid Vectors / Q000469:parasitology*; D001399:Azure Stains; D001403:Babesia / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification; D001404:Babesiosis / Q000469:parasitology / Q000662:veterinary*; D001483:Base Sequence; D001938:Brazil; D016054:DNA, Protozoan / Q000737:chemistry / Q000302:isolation & purification; D005260:Female; D006734:Horse Diseases / Q000469:parasitology* / Q000635:transmission; D006736:Horses; D026863:Ixodidae / Q000469:parasitology*; D008297:Male; D008970:Molecular Weight; D016133:Polymerase Chain Reaction / Q000662:veterinary
D001399:Azure Stains; D016054:DNA, Protozoan