Prevalence and Genetic Heterogeneity of Bartonella Strains Cultured from Rodents from 17 Provinces in Thailand

To study the distribution and diversity of Bartonella in rodents from Thailand, 330 rodents belonging to 13 species were tested. The majority (80.6%) of rodents examined belonged to the genus Rattus . Bartonellae were cultured from 41.5% of the rodents with a wide range of prevalence by host species and regions. Sequencing of gltA revealed diverse Bartonella strains. Bartonellae from Rattus spp. belonged to 23 variants and clustered with Bartonella coopersplainensis , Bartonella elizabethae , Bartonella phoceensis , Bartonella rattimassiliensis , Bartonella tribocorum , and an unknown geno- group. Bartonellae from Bandicota spp. belonged to six variants and clustered with B. coopersplainensis , B. rattimassilliensis , and B. tribocorum . Three variants from Mus spp. clustered with B. coopersplainensis or B. rattimassilliensis. The only iso- late from a Berylmys berdmorei fell into the B. tribocorum group. The observations highlight the need to study these agents for their role in human febrile illnesses of unknown etiology in Thailand and elsewhere in Asia. re - ported the presence of bartonellae in rodents in the north- ern province of Chiang Rai. Importantly, a number of isolates obtained from the study were closely related to B. grahamii and B. elizabethae , species that have been associated with human illness. 13,14 The high prevalence of these bacteria in rodents in some communities in Asian countries and the close contact of people with rodents and their ectoparasites increases the like- lihood that rodent-borne bartonellae are a significant cause of human morbidity in Thailand. To better understand the dis- tribution and diversity of Bartonella in rodents from Thailand, we analyzed rodent samples collected from 17 provinces across Thailand and characterized the isolates by molecular techniques. The objectives of this study were to 1) study the preva- lence of Bartonella species in rodents from different parts of Thailand by culturing blood samples, 2) evaluate the genetic diversity of recovered Bartonella strains, 3) study host-spec- ificity of Bartonella strains in Thailand, and 4) compare Bartonella strains obtained from rodents in Thailand with those from other countries.