First epidemiological and molecular report of ticks and tick-borne
pathogens in small ruminants across North and North-western Pakistan
Abstract
Mapping the distribution of ticks and tick-borne pathogens linked to
their molecular information from previously unexplored geographic areas
provide valuable information about the cryptic tick fauna and their
associated pathogens of zoonotic and veterinary importance. The present
research was designed to investigate the epidemiologic and phylogenetic
aspects of ticks and tick-borne pathogens infesting goats and sheep in
the north and north-western territories of Pakistan. A total of 1587
ixodid ticks were collected from goat and sheep herds (n = 600). The
collected ticks were taxonomically classified using morphological keys
and the molecular markers 16S rRNA and COI. The presence of
tick-borne pathogens in collected ticks was assessed by PCR targeting
the genetic markers 16S rRNA and gltA for bacterial pathogens,
and 18S rRNA for Apicomplexan parasites. The morpho-molecular
characterization of hard ticks revealed three ixodid tick genera (
Hyalomma, Haemaphysalis, and Rhipicephalus) which included
11 tick species viz. Hy. anatolicum (5.9%) , Hy.
dromedarii (9.1%), Hy. excavatum (2.8%), Hy. isacci
(5.1%) , Hy. scupense (7.7%), Hae. montgomeryi (18.3%)
, Hae. sulcata (6.5%), Rh. decoloratus (4.4%) ,
Rh. haemaphysaloides (13.2%) , Rh. microplus (10.8%) ,
and Rh. turanicus (16.2%). Amplified tick 16S rRNA and
COI nucleotide sequences shared 99.74-100% similarity and
clustered phylogenetically with similar tick species reported previously
in China, India, Iran, Saudi Arabia, Sri Lanka, South Africa, Turkey,
and Pakistan. The 16S rRNA , 18S rRNA and gltA nucleotide
sequences of detected tick-borne pathogens, including R.
massiliae (24.5%) followed by T. ovis (16.4%), A. capra
(9.1%), T. luwenshuni (6.4%), A. ovis (5.9%), R.
hoogstraalii, (5.0%), Anaplasma spp. (4.5%), Ehrlichia
spp. (4.5%), Rickettsia spp. (4.5%), T. annulata
(4.1%) and A. marginale (3.6%), shared 99.48-100% similarity
and grouped with sequences previously reported in South Asia, middle
east Africa and USA. This study showed for the first time the presence
of two tick ( Hae. montgomeryi and R. decoloratus) and one
tick-borne pathogen species ( R. hoogstraali) in Pakistan. Our
results are the first available reports documenting important ticks and
tick-borne pathogens of veterinary and public health concern from
previously neglected parts of Pakistan. These results could be used as a
baseline to facilitate future large-scale epidemiological and molecular
studies about ticks and tick-borne pathogens of small ruminants at the
local and global levels.