Multi-locus Sequencing Typing of Bartonella henselae isolates reveals coinfection with different variants in domestic cats from Midwestern Brazil.

Bartonella henselae is a zoonotic pathogen responsible for causing Cat Scratch Disease (CSD) and other clinical manifestations in humans. Domestic cats are the main reservoirs of this Bartonella species. Previous studies have suggested that certain genotypes of B. henselae seem to be more associated with human infections. The present study aimed to genotype B. henselae isolates from domestic cats' blood samples in the state of Goiás, midwestern Brazil. The association of quantitative real-time PCR (qPCR) based on the nuoG gene from Bartonella spp. of blood samples, before and after incubation in pre-enrichment liquid medium (BAPGM) and isolation on chocolate agar, showed a positivity frequency of 42% (42/100) for Bartonella spp. Twelve B. henselae isolates obtained on agar chocolate from six cats' blood samples (two isolates from each animal) were characterized by Multi-locus Sequencing Typing (MLST) and revealed to belong to Sequence Types ST1 and ST5. One of the cats (1/6) presented both STs, demonstrating that domestic cats can be coinfected with different variants of B. henselae. The STs detected in this study are distributed worldwide and have already been detected in humans with clinical manifestations of bartonellosis. This is the first report of the zoonotic variants ST1 and ST5 of B. henselae in domestic cats from Brazil.