Abstract
Rickettsioses is a group of emerging infectious diseases in Southeast Asia caused by Gram-negative obligate intracellular bacteria in the Rickettsiae tribe. However, there is limited information regarding the vertebrate hosts of Rickettsia spp. in this region. This study aims to detect and identify Rickettsia agents present in wildlife and domesticated animals in Malaysia using Polymerase Chain Reaction (PCR) and sequencing of citrate synthase gene (gltA), followed by genotyping and phylogenetic analysis. Rickettsia sp. was detected in 2 (0.67%) of 300 wildlife and domesticated animal blood samples. The positive samples were derived from a goat (5.56% of 18) and a sheep (2.22% of 45). Both sequences demonstrated 99.64% sequence similarity to Rickettsia asembonensis, a species that is known to infect humans and macaques. This study reported for the first time the detection of R. asembonensis in sheep and goats in Malaysian farms, suggesting this species may be adapting to a wider range of animals, specifically farm animals. Therefore, this bacterium may pose a zoonotic threat to the local community particularly to the farmworkers or animal handlers. The low infection rate of this pathogen across different animals highlighted the need of continuous surveillance of emerging and reemerging pathogens among animal populations.
Highlights
Rickettsioses is a neglected infectious disease in Southeast Asia despite being one of the leading causes of treatable unrecognized febrile illnesses
Through Basic Local Alignment Search Tool (BLAST) analysis, the sequence obtained from the goat (G325) and sheep (S102) both demonstrated 99.64% sequence similarity to Rickettsia asembonensis (MK923743), a recently discovered isolate from the ectoparasites of domestic animals in Peru, distinct from the original Kenya strain (Maina et al, 2016)
The neighbour joining dendrogram constructed based on the gltA gene sequence in Fig. 1 revealed that both sequences G325 and S102, clustered with the respective reference R. asembonensis sequences (KY445724, KY445725, KX196267, AF516333) retrieved from the NCBI GenBank and showed a close relationship with R. senegelensis confirming the findings obtained from the BLAST analysis
Summary
Rickettsioses is a neglected infectious disease in Southeast Asia despite being one of the leading causes of treatable unrecognized febrile illnesses. Rickettsia typhi and some members of spotted fever group Rickettsia, exemplify important species that causes human disease among the local population (Aung et al, 2014). One of the hallmarks of Rickettsia is their ability to adapt to a wide variety of hosts (Weinert et al, 2009). Rickettsia is maintained in nature in a continuous cycle between infected arthropods, and one or several of host animals. The possibility of other animals as reservoirs of these emerging pathogens has gained the attention of researchers worldwide. Several studies across Southeast Asia have reported rickettsial infections in animals such as wild rodents, dogs, monkeys and a range of hematophagous arthropods (Low et al, 2020)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
