First molecular phylogeny of Bartonella bovis in Iraqi cattle.

Abstract

Background: Bartonella bovis is one of the most neglected fastidious intracellular bacterial pathogens that infect a wide range of wild and domestic animals, including cattle.

Aim: Detection of the prevalence of B. bovis in cattle using molecular assay, identification of the relationship of infection to animal risk factors (age and sex), and sequencing of B. bovis isolates to be analyzed phylogenetically and reported in the National Centre For Biotechnology Information (NCBI).

Methods: A total of 290 cattle were selected randomly from different rural areas in Wasit province from September to December (2023), and subjected to collecting venous blood samples that were tested molecularly by the polymerase chain reaction (PCR). Phylogenetic analysis was conducted using the MEGA 7 Software.

Results: Targeting the 16S rRNA gene, 7.24% of the study cattle tested positive for B. bovis. In terms of age, positivity rates, odds ratios (ORs), and relative risks (RRs) were significantly higher in cattle older than 7 years compared to other age groups: under 1 year, 1-3 years, and 3-7 years. Regarding sex, there was no significant variation in positive rates between females (7.48%) and males (5.56%); however, the OR and RR values indicated that females (1.376 and 1.345, respectively) were at a higher risk of B. bovis infection than males (0.727 and 0.743, respectively). Phylogenetic tree analysis of five local B. bovis isolates demonstrated their identity with the France strain/isolate at total genetic identity ranging from 99.64% to 99.98%.

Conclusion: To the best of our knowledge, this study represents the first molecular identification of the prevalence rate of B. bovis in cattle in Iraq using PCR assay and confirms phylogenetically the local B. bovis isolates in NCBI-BLAST. Therefore, additional information about the prevalence, genetic diversity in domestic and wild animals, and arthropod vectors is crucial for developing strategies for the prevention and control of B. bovis infections.