Tick Species Identification and Zoonotic Bacteria Detection from Healthcare-Extracted Specimens from Humans in the...

Hard ticks are vectors of a wide range of pathogens, with tick-borne bacteria being among the most frequently detected. This study presents a first approach to the identification of human-biting ticks in the Basque Country (northern Iberian Peninsula), where previous research has mainly focused on ticks from vegetation and domestic and wild animals. The aim of this study was (i) to identify tick species collected in hospitals and health centres and (ii) to determine the presence and identify of pathogenic bacteria that they may carry using PCR, RLB and sequencing methods. A total of 181 ticks were collected and grouped in pools of one, two or three specimens, resulting in 157 samples. Morphological and molecular identification of collected ticks revealed that most specimens belonged to Ixodes ricinus (88.5%). Additionally, Rhipicephalus bursa, Haemaphysalis punctata, Dermacentor reticulatus and Dermacentor marginatus were also identified. A total of 25 samples (15.9%) tested positive for DNA from the targeted pathogens. The most prevalent vector-borne bacteria were Borrelia spp. (6.4%), followed by Rickettsia spp. (5.1%), Anaplasma phagocytophilum (2.5%) and Coxiella spp. (1.9%). Species identified included B. afzelii, B. garinii, B. miyamotoi, B. valaisiana, B. burgdorferi s. s., R. monacensis, "Candidatus R. rioja", R. helvetica and R. massiliae. This study highlights the usefulness of combining molecular diagnostics with passive surveillance of human-attached ticks as an effective tool for regional monitoring of ticks and tick-borne pathogens.