Molecular and serological detection of tick-borne pathogens in donkeys (Equus asinus) in Italy

Donkeys, owing to the frequent outdoor activity, are exposed to a high risk of infection with tick-borne pathogens. This work aimed to detect exposure to Theileria equi, Babesia caballi, Anaplasma phagocytophilum and Borrelia burgdorferi s.l. of donkeys reared in Central Italy. For this purpose 122 adult donkeys were selected within 11 herds and submitted to blood collection. IgG antibodies to T. equi, B. caballi, A. phagocytophilum and B. burgdorferi s.l. were detected by IFAT. Conventional PCRs targeting the genes MSP2 and the flagellin were used for the detection of A. phagocytophilum and B. burgdorferi s.l. respectively and a Real Time PCR Sybr Green was used to detect Babesia/Theileria spp…. The species identity was determined by amplicons sequencing. Forty eight (39.3%) and 58 (47.5%) animals tested positive for T. equi and B. caballi antibodies, respectively; nine animals (7.4%) were found positive for antibodies against A. phagocytophilum whereas negative results were obtained for B. burgdorferi s.l. Twenty-six (21.3%) animals showed antibodies for both T. equi and B. caballi. Twenty-three (18.8%) donkeys were positive to Babesia/Theileria spp. PCR assay. Out of 21 sequenced amplicons, 20 were identified as T. equi, belonging to three main groups designated A, B and D and one as B. caballi group A. Neither A. phagocytophilum nor B. burgdorferi PCR results were positive. The study showed a high exposure of donkeys to tick-borne pathogens and provides information on the genetic identity of the T. equi strains circulating in Central Italy.