1.Construction of multi-epitope vaccine against the Rhipicephalus microplus tick: an immunoinformatics approach
Younas, M. ; Ashraf, K. ; Ijaz, M. ; Suleman, M. ; Chohan, T.A. ; Rahman, S.U. ; Rashid, M.I.
Tropical Biomedicine 2024;41(No.1):84-96
Rhipicephalus microplus, known as the hard tick, is a vector for the parasites Babesia spp. and
Anaplasma marginale, both of which can cause significant financial losses to the livestock industry.
There is currently no effective vaccine for R. microplus tick infestations, despite the identification of
numerous prospective tick vaccine candidates. As a result, the current research set out to develop
an immunoinformatics-based strategy using existing methods for designing a multi-epitope based
vaccination that is not only effective but also safe and capable of eliciting cellular and humoral immune
responses. First, R. microplus proteins Bm86, Subolesin, and Bm95 were used to anticipate and link B
and T-cell epitopes (HTL and CTL) to one another. Antigenicity testing, allergenicity assessment, and
toxicity screening were just a few of the many immunoinformatics techniques used to identify potent
epitopes. Multi-epitope vaccine design was chosen based on the antigenic score 0.935 that is promising
vaccine candidate. Molecular docking was used to determine the nature of the interaction between TLR2
and the vaccine construct. Finally, molecular dynamic simulation was used to assess the stability and
compactness of the resulting vaccination based on docking scores. The developed vaccine was shown
to be stable, have immunogenic qualities, be soluble, and to have high expression by in silico cloning.
These findings suggest that experimental investigation of the multi-epitope based vaccine designed in
the current study will produce achievable vaccine candidates against R. microplus ticks, enabling more
effective control of infestations.
2.Molecular prevalence of Anaplasma marginale in ruminants and Rhipicephalus ticks in northern Pakistan
Ali, S. ; Hasan, M. ; Ahmad, A.S. ; Ashraf, K. ; Khan, J.A. ; Rashid, M.I.
Tropical Biomedicine 2023;40(No.1):7-13
Anaplasma marginale is the most prevalent tick-borne haemoparasite of cattle and causes huge
economic losses to the dairy industry worldwide. This study aimed to determine the occurrence of A.
marginale infection in blood and tick samples collected from livestock animals in the districts located
in Khyber Pakhtunkhwa (KPK), Pakistan. A total of 184 blood and 370 tick samples were included in this
study. It has never been reported that sheep, goats, and cattle in Tank, Ghulam Khan, Birmil and Miran
Shah areas were infected with A. marginale. All samples of blood and ticks were collected through
random sampling from March 2021 to January 2022 from cattle, sheep and goats and screened through
PCR for anaplasmosis by using primer pairs of Anaplasma spp. Three hundred and seventy ticks were
collected from infested hosts (120/184, 64.21%). Among the four morphologically identified tick species,
the highest occurrence was recorded for Rhipicephalus sanguineus (n=138, 37.29%), followed by
Rhipicephalus microplus (n=131, 35.4%), Rhipicephalus annulatus (n=40, 10.81%), Hyalomma anatolicum
(n=31, 8.37%), and Hyalomma marginatum (n=30, 8.1%). The occurrence of female tick was highest
(n=160, 43.24%), followed by nymphs (n=140, 37.38%) and males ticks (n=70, 18.9%). Among these ticks,
A. marginale was detected in female ticks of R. microplus, and R. sanguineus. Molecular identification
of A. marginale was confirmed in 120 out of 184 blood samples and 6 out of 74 tick samples. Overall,
occurrence of A. marginale in blood and tick samples was found to be 65.21% and 8.1% respectively.
Species-wise occurrence in blood samples of goats were 71.11% followed by sheep 68.31% and cattle
50%. Specie-wise occurrence of A. marginale in tick samples of cattle were 12.5% followed by goats
6.89%. The obtained sequence showed similarity with A. marginale reported from Kenya and USA. We
report the first PCR based detection of A. marginale infection in blood samples and in R. sanguineus
ticks of goats simultaneously.