Prevalence and Genetic Diversity of Bartonella Species Detected in Different Tissues of Small Mammals in Nepal

Abstract

Bartonellae were detected in a total of 152 (23.7%) of 642 tissues from 108 (48.4%) of 223 small mammals trapped in several urban areas of Nepal. Based on rpoB and gltA sequence analyses, genotypes belonging to seven known Bartonella species and five genotypes not belonging to previously known species were identified in these animals.Bartonella species are important zoonotic and vector-borne bacteria associated with an increasing array of emerging infections in humans and animals (6,8,21). Identification of new bartonellae, especially in animals that have possible contact with humans, can help to identify new human pathogens (12). Moreover, the close association between rodents and humans throughout the world makes the study of rodent-borne Bartonella essential to determine the extent to which rodents may serve as a source of human infections (7). We conducted a study on the molecular detection of Bartonella in different tissues of Nepalese small mammals.In 1996, a total of 223 small mammals (38 Bandicota bengalensis, 3 Mus musculus castaneus, 90 Rattus rattus brunneusculus, and 92 Suncus murinus animals) were trapped in densely human populated urban areas in Nepal. Details on the trapped animals are given in Table 1. Lung, kidney, and liver tissue samples were collected and shipped to the Centers for Disease Control and Prevention (CDC), Fort Collins, CO. A total of 642 tissue samples were assessed for the presence of Bartonella DNA by rpoB and gltA sequencing as described previously (5, 23).Bartonella was detected in 108 (48.4%) of 223 animals in Nepal: 10 (26.3%) of 38 B. bengalensis rats, 39 (43.3%) of 90 R. rattus brunneusculus rats, and 59 (64.1%) of 92 S. murinus shrews were infected with Bartonella (Table 1). The infection rate varied from 42 to 60% by province. The highest numbers of infected animals were in the Kathmandu and Lalitpur districts. This was because S. murinus was the most commonly infected species and the highest numbers of animals of this species were trapped in these areas. Bandicoots were the most commonly infected subjects in Kathmandu, but fewer numbers of these animals (n ϭ 2) were trapped in Bhaktapur and Lalitpur. Only three M. musculus mice were collected (only in Kathmandu) in this study, and none of these animals were positive for Bartonella. A total of 152 (23.7%) of 642 tissue samples were positive for Bartonella. Of the three tissue types, kidney samples (29.6%) and liver samples (25.6%) were more frequently infected with Bartonella than the lung samples (17.3%; P ϭ 0.03 and 0.04, respectively) ( Table 2). DNA sequencing revealed 37 and 20 rpoB and gltA genotypes, respectively, of which 31 and 15 belonged to B. rattimassiliensis, B. queenslandensis, B. elizabethae, B. tribocorum, "B. rochalimae," or "B. phoceensis" and the other 6 and 5 genotypes, respectively, were not genetically related to known bartonellae ( Fig. 1 and 2). These novel genetic groups were found in S. murinus and R. rattus brunneusculus animals. The human pathogen B. elizabethae was detected in R. rattus br...

Global distribution and genetic diversity of Bartonella in bat flies (Hippoboscoidea, Streblidae, Nycteribiidae)

“…However, most GenBank data for Bartonella includes only gltA sequences (i.e., no 16S rDNA). We therefore employed a network approach to explore a more extensive data set, combining GenBank data (Concannon et al, 2005;Abbot et al, 2007;Harrus et al, 2009;Kosoy et al, 2009Kosoy et al, , 2010Bai et al, 2010Bai et al, , 2011Gundi et al, 2010;Billeter et al, 2012) with sequences generated in this effort [Tables 1 and S1]. The advantage of a network approach is that it avoids representation of strict binary sequence relationships, and rather presents simultaneous alternative connections.…”

Genotyping ofBartonellabacteria and their animal hosts: current status and perspectives

“…Only one study focused on detecting and genotyping Bartonella DNA in cat blood found the ITS and gltA targets to be equally productive (Bai et al 2015b). While detecting and genotyping Bartonella in rodent spleens, two studies reported successful identification in more specimens by targeting the rpoB gene compared with the gltA (Gundi et al 2010(Gundi et al , 2012b). …”

Isolation and Molecular Identification of Bartonellae from Wild Rats (Rattus Species) in Malaysia

“…4,5 The occurrence of bartonellae in rodents and other small mammals has been reported in several countries in Asia, including Bangladesh, China, Indonesia, Japan, Laos, Cambodia, Taiwan, Nepal, and Thailand. [6][7][8][9][10][11][12][13][14][15][16][17] Bartonella tribocorum, B. rattimassiliensis, B. coopersplainsensis, B. elizabethae, and B. queenslandensis are among those that have been identified from the wild rats (Rattus species). Arthropod vectors, particularly fleas (Ctenocephalides felis) and ticks (Ixodes, Haemaphysalis), are often implicated in the natural maintenance of various species of bartonellae.…”