Molecular detection and prevalence of Anaplasma and Rickettsia species in rodents captured from wildlife-human interfaces in Iringa and Morogoro regions, Tanzania

Abstract

Rickettsia and Anaplasma are Gram-negative, nonmotile, obligate intracellular bacteria in the order Rickettsiales. While various studies have been conducted on these threatening pathogens in humans and domestic animals, the potential role of small mammals as reservoir in zoonotic transmission is poorly understood in Tanzania. This study investigated the prevalence and identity of Rickettsia and Anaplasma infecting small mammals captured at wildlife-human interfaces in Iringa and Morogoro, Tanzania. A total of 371 blood samples were analyzed using conventional PCR and DNA fragment sequencing, targeting approximately 424 bp of the 16S rRNA gene for Anaplasma and 383 bp of the citrate synthase (gltA) gene for Rickettsia. Anaplasma spp. DNA was detected in 9.7 %, and Rickettsia spp. in 6.74 % of the samples. Rattus rattus exhibited the highest prevalence for both Anaplasma (21.43 %) and Rickettsia (28.57 %). Two Anaplasma species (A. bovis and A. ovis) and three Rickettsia species (R. asembonensis, R. felis and R. typhi) were confirmed through sequence analysis. This study highlights the presence of Anaplasma and Rickettsia DNA in captured rodents, indicating the potential role of rodents in the maintenance and transmission of these pathogens, especially at wildlife-human interfaces, also reports the presence of R. asembonensis in rodents for the first time in Tanzania.