<i>Bartonella</i> tracing in wild rodents in northwestern Mexico

<i>Bartonella</i> is a widely distributed Gram-negative bacterium that includes species that are capable of causing illness in humans. Rodents represent one of the main reservoirs of zoonotic pathogens, and monitoring their populations can provide valuable insights into human health. We conducted a surveillance study of rodents from two north-western states of Mexico (Baja California and Chihuahua) to investigate the prevalence and genetic diversity of <i>Bartonella</i> by polymerase chain reaction (PCR) amplification and sequencing of the citrate synthase (<i>gltA</i>) gene. A total of 586 rodents belonging to 28 species were captured, and 408 were tested for <i>Bartonella</i> spp. The overall <i>Bartonella</i> spp. prevalence was 39.71%. The prevalence found in Chihuahua was higher (42.80%) than in Baja California (32.52%), and rodents such as <i>Neotoma albigula</i>, <i>Neotoma mexicana</i>, <i>Peromyscus boylii</i>, and <i>Chaetodipus baileyi</i> had the highest prevalence. The <i>gltA</i> sequences revealed seven genetic variants, some of which were obtained from <i>Peromyscus</i> and <i>Dipodomys</i> rodents and were associated with <i>Bartonella</i> species of human health concern, such as <i>B. grahamii</i> and <i>B. vinsonii</i> subsp. <i>arupensis.</i> In addition, a sequence obtained from a <i>Peromyscus maniculatus</i> was clustered with <i>Candidatus</i> Bartonella rudakovii, a previously unreported association. This study provides valuable data and new insight into the <i>Bartonella</i>-hosts interactions in rodent species in north-western Mexico.