Work

Molecular detection and phylogenetic characterization of Coxiella burnetii in dairy cattle from the Al Ain region, United Arab Emirates

Year: 2026

Type: preprint

Abstract: Coxiellosis (Q fever), caused by Coxiella burnetii , is a globally important zoonosis with significant implications for livestock production and public health. Although serological evidence indicates endemic exposure in dairy cattle in the United Arab Emirates (UAE), molecular data on circulating strains and shedding dynamics remain limited. This study investigated C. burnetii infection and genetic characteristics in commercial dairy herds in the Al Ain region of the UAE using combined serological and molecular approaches. A cross-sectional study was conducted on two commercial dairy farms, where 400 cattle were sampled for blood, milk, and vaginal swabs. Serological testing by indirect ELISA revealed an overall seroprevalence of 30.0% (95% CI: 25.6–34.8%), with no significant difference between the study farms. PCR detection identified C. burnetii DNA exclusively in milk samples from seropositive animals (21.7%; 95% CI: 14.8–29.9%), indicating active mammary shedding, while no bacterial DNA was detected in blood or vaginal swabs. Sanger sequencing and phylogenetic analysis based on the htpB gene demonstrated complete sequence homogeneity among UAE isolates and clustering within globally distributed zoonotic lineages. These findings provide integrated molecular and epidemiological evidence of endemic C. burnetii infection and active milk shedding in UAE dairy cattle. The results suggest that mammary-associated shedding may play a key role in maintaining infection within herds and highlight the importance of combining serological and molecular approaches for accurate surveillance. This study contributes baseline molecular data from an underreported region and supports the need for One Health-oriented control strategies to mitigate both animal and public health risks.

Source: Research Square

DOI: 10.21203/rs.3.rs-10032589/v1