RESUMO
The 120-kD protein gene of Ehrlichia chaffeensis was used to characterize ehrlichial DNA from seven pools of adult Amblyomma americanum ticks. Ticks from Missouri, Kentucky, and North Carolina contained E. chaffeensis DNA of the Arkansas strain genotype. Ticks from North Carolina also contained ehrlichiae of the Sapulpa strain genotype, originally identified in Oklahoma.
Assuntos
Ehrlichia chaffeensis/genética , Ehrlichiose/epidemiologia , Animais , DNA/genética , Ehrlichiose/genética , Reação em Cadeia da Polimerase , Sequências Repetitivas de Ácido Nucleico , Carrapatos , Estados Unidos/epidemiologiaRESUMO
Polymerase chain reaction primers specific for Ehrlichia chaffeensis were used to amplify DNA from extracts of pooled ticks. Amplification was performed on extracts from 140 pools (1,579 total ticks) consisting of three tick genera collected from five states. The characteristic 389-basepair product was observed after amplification of extracts from seven different pools of adult Amblyomma americanum (117 pools, 1,462 ticks), but not from pools of nymphs. No specific product was observed after amplification of 20 pools (105 ticks) of Dermacentor variabilis and three pools of Ixodes scapularis (12 ticks). Ehrlichia chaffeensis was present in A. americanum at a minimum frequency of > or = 0.48%, suggesting that A. americanum may be a vector of human ehrlichiosis.
