Epidemiology and Infection

Special Article

Genotypic evaluation of rickettsial isolates recovered from various species of ticks in Portugal

F. Bacellara1, R. L. Regnerya2, M. S. Núncioa1 and A. R. Filipea1a3 c1

a1 Centra de Estudos de Vectores e Doenças Infecciosas do Institute National de Saúde, 2965 Áquas de Moura, Portugal

a2 Centers for Disease Control and Prevention, Division of Viral and Rickettsial Diseases, US Department of Health and Human Services, Public Health Service, Atlanta, Georgia 3033, USA

a3 Escola National de Saúde Pública, Universidade Nova de Lisboa, 1699 Lisboa, Portugal


Twelve rickettsial isolates, from Rhipicephalus sanguineus, R. turanicus, Dermacentor marginatus and Hyalomma marginatus, were subjected to genotypic analysis. Amplification of specific DNA sequences, restriction endonuclease digestion of amplified DNA products, and gel electrophoresis were used to identify specific DNA fragment-banding patterns. Five patterns were resolved. Four were homologous with those of previously described rickettsial genotypes, R. conorii, R. slovaca, R. rhipicephali and R. massiliae. The fifth pattern differed by only a single altered restriction endonuclease cleavage site. For the first time in Portugal a widely distributed spectrum of spotted fever group rickettsia was found among potential vector species stressing the need to determine their potential for human and domestic animals infection.

(Accepted September 01 1994)


c1 Professor Armindo R. Filipe, Centre de Estudos de Vectores e Doenças Infecciosas, 2965 Aguas de Moura, Portugal.