Molecular detection of tick-borne pathogens in Ixodes ricinus from Moldova collected in 1960

This study is the first report about the prevalence of tick-borne pathogens, as well as their (co-)infection rates, in the museum-archived I. ricinus female ticks collected in Moldova in 1960. A total of 16.7% (21/126) ticks was mono-infected. Borrelia burgdorferi sensu stricto was revealed as the most abundant species (4.8%) followed by B. garinii (1.6%), B. afzelii (0.8%), B. valaisiana (0.8%), and B. lusitaniae (0.8%). DNA of Rickettsia helvetica (2.4%), R. monacensis (2.4%), Anaplasma phagocytophilum (2.4%), 'Candidatus Neoehrlichia mikurensis' (0.8%), and Babesia microti (0.8%) were also detected, indicating the occurrence of these emerging tick-borne microorganisms in Moldova since 1960 at least. In this study, we detected a co-infection (0.8%; 1/126 tested ticks) between B. microti and R. helvetica. Additional investigations are warranted to further characterize a historical snapshot of the distribution of tick-borne pathogens in Europe.