A higher infection rate of Toxoplasma gondii in soft ticks infesting domestic hens: A novel report from Pakistan

Abstract

Ticks are the second most important hematophagous ectoparasites after mosquitoes and serve as vectors for various pathogens, transmitting them to wild and domestic animals, as well as humans. Argas persicus are the soft ticks that are known to parasitize domestic poultry. Hard ticks are known to be the reservoir of Toxoplasma (T.) gondii but limited such information is available for soft ticks. This study reports the molecular prevalence and phylogenetic analysis of T. gondii infecting Argas (A.) persicus ticks (N = 70), collected from four domestic poultry breeds in the Kurram District, Khyber Pakhtunkhwa, Pakistan, between June and August 2023. The results showed that 26 out of 70 (37 %) A. persicus samples tested positive for the ITS-1 gene of T. gondii. These findings were confirmed by the DNA sequencing and BLAST analysis of amplified amplicons. Phylogenetic analysis showed that Pakistani isolates were genetically diverse and clustered with isolates that were reported from birds and mammals from Pakistan, Tunisia, Malaysia, Brazil and Iraq. Risk factor analysis indicated that the prevalence of T. gondii was not associated with any specific poultry breed, sampling period, or the body temperature of the fowl hosts. Similarly parasite prevalence was not found associated with tick sex or their developmental stage but parasite infection rate varied with the feeding status of the ticks; highest T. gondii infection rate was observed in fully fed Argas persicus. In conclusion, this is the first report from Pakistan highlighting a high prevalence of T. gondii in A. persicus infesting domestic poultry suggesting a potential zoonotic risk to humans through the consumption of infected poultry. This data is confirming that in addition to oral ingestion of oocysts, T. gondii can be mechanically transmitted through soft ticks.

Keywords: Argas persicus; Domestic hen; Molecular prevalence; Pakistan; Phylogeny; Toxoplasma gondii.