Parasites and Vectors (2019) 12 (12) - Low genetic diversity of ...

Alejandro Cabezas-Cruz, Eleonore Allain, Abdullah S. Ahmad, Muhammad A. Saeed, Imran Rashid, Kamran Ashraf, Lena Yousfi, Wasim Shehzad, Lea Indjein, Manuel Rodriguez-Valle, Agustin Estrada-Peña, Dasiel Obregón, Abdul Jabbar and Sara Moutailler (2019)
Low genetic diversity of Ehrlichia canis associated with high co-infection rates in Rhipicephalus sanguineus (s.l.)
Parasites and Vectors 12 (12)
Abstract:
Background
Rhipicephalus sanguineus sensu lato (s.l.) is the most widely distributed ixodid tick and is a vector of major canine and human pathogens. High-throughput technologies have revealed that individual ticks carry a high diversity of pathogens, including bacteria, protozoa and viruses. Currently, it is accepted that co-infections (multiple pathogen species within an individual) are very common in ticks and influence pathogen acquisition and transmission as well as host infection risk. However, little is known on the impact of the genetic diversity of pathogens on the incidence of co-infections. Herein, we studied the frequency of co-infections in R. sanguineus (s.l.) and their association with the genetic diversity of Ehrlichia canis.
Methods
Rhipicephalus sanguineus (s.l.) female ticks (n = 235) were collected from healthy farm dogs in three districts of Pakistan. Microfluidic real-time PCR, a powerful nanotechnology for high-throughput molecular detection of pathogens, was used to test the presence of 25 bacterial and seven parasitic species in individual ticks. The genetic diversity of E. canis was evaluated by characterizing the trp36 gene.
Results
A total of 204 ticks were infected with at least one pathogen and 109 co-infected with two (80%) or three (20%) pathogens. Rickettsia massiliae (human pathogen) and E. canis (zoonotic dog pathogen) were the most common pathogens co-infecting (30.4%) ticks. Furthermore, all identified co-infections included R. massiliae and/or E. canis. Multiple correspondence analysis (MCA) revealed that single infections did not show clear regional association whereas some co-infections were restricted to certain geographical regions. The sequence analysis of trp36 in representative samples allowed the identification of three E. canis strains with low genetic diversity, and the strain found in Muzaffargarh district appeared to be more adapted to co-infection with R. massiliae.
Conclusions
Rhipicephalus sanguineus (s.l.) harbors multiple co-infections with human and dog pathogens of zoonotic potential. Findings of this study suggest that genetic diversity of E. canis may favor co-infections with different pathogens.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Full text of article
Database assignments for author(s): Manuel Rodriguez-Valle, Agustin Estrada-Pena, Sara Moutailler

Research topic(s) for pests/diseases/weeds:
general biology - morphology - evolution

---

Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Rhipicephalus sanguineus		Pakistan