First molecular phylogeny of in Iraqi cattle.

BACKGROUND

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 in cattle using molecular assay, identification of the relationship of infection to animal risk factors (age and sex), and sequencing of 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 gene, 7.24% of the study cattle tested positive for . 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 infection than males (0.727 and 0.743, respectively). Phylogenetic tree analysis of five local 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 in cattle in Iraq using PCR assay and confirms phylogenetically the local 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 infections.