First isolation and genomic insights of Bartonella henselae from domestic cats and dogs in Costa Rica.

Bartonella spp. are vector-borne zoonotic pathogens responsible for cat-scratch disease and several other human disease manifestations. Previous studies in Costa Rica have reported Bartonella DNA in ectoparasites and bats; however, data from companion animals remain limited. Here, we investigated the occurrence of Bartonella spp. in domestic cats and dogs and characterized the circulating strains using molecular, culture-based, and genomic approaches. Blood samples were collected from 152 domestic cats and 188 domestic dogs from different Costa Rican regions. Conventional polymerase chain reaction (PCR) assays targeting citrate synthase (gltA) and the beta subunit of bacterial RNA polymerase (rpoB) were used to detect Bartonella spp. DNA was detected in 44% of the cats and 34% of the dogs. Partial gltA sequencing identified B. henselae, B. rochalimae, and B. clarridgeiae. Four B. henselae isolates recovered from feline blood were subjected to whole-genome sequencing. Comparative pan-genome and multilocus sequence typing (MLST) analyses identified sequence types ST1 and ST5 circulating in Costa Rica. These findings provide the first genomic characterization of Bartonella spp. from companion animals in Costa Rica and expand the current knowledge of the genetic diversity and epidemiology of Bartonella in Central America.