Diversity of Ticks in the Caribbean Region and Detection of Their Pathogens Using BioMark Technology

Ticks and the pathogens they transmit are widespread in Caribbean animal populations. There is; however, limited information on the diversity of ticks and tick-borne pathogens (TTBPs) in the region. This study aims to identify TTBPs across multiple Caribbean countries using a high-throughput real-time microfluidic PCR system.

Six Caribbean territories: Barbados, Guyana, St. Kitts, St. Lucia, Tobago and Trinidad were targeted in this study. Nucleic acids were extracted from individual ticks, and a high-throughput microfluidic real-time PCR system was used to screen for 49 bacterial species (10 genera) and 18 protozoan species (six genera). Five tick species were detected using morphological or molecular techniques.

A total of 840 ticks were tested from 155 dogs and 111 cattle. Morphological and molecular diagnostic methods detected five tick species: Rhipicephalus sanguineus sensu lato (s.l.), Rhipicephalus microplus, Amblyomma variegatum, Amblyomma ovale and Amblyomma cajennense s.l. Overall, the DNA of 18 pathogens belonging to eight genera was detected in 22.5% (189/840) ticks obtained from both cattle (96/335) and dogs (93/505). The most prevalent pathogens were Anaplasma marginale 14% (47/335) and Hepatozoon canis 3.4% (17/505) in cattle and dog ticks, respectively. Dual and triple infections were also detected in 3.3% (n = 28) and 0.6 % (n = 5) of tested ticks, respectively. The DNA of Ehrlichia ruminantium was detected in R. sanguineus and A. variegatum from dogs in Barbados- a first record for this island. Another key finding was the novel detection of a Borrelia sp. in a R. sanguineus s.l. tick from Trinidad.

The high diversity of pathogens detected in this study, with some being of veterinary and public health importance, highlights the strength of the high-throughput microfluidic real-time PCR system as a surveillance tool for the efficient and rapid detection of tick-borne pathogens (TBPs) of veterinary, public health and economic significance in the Caribbean.