Coxiella burnetii in cattle and their human contacts in a gaushala (cattle shelter) from India and its partial com1 gene sequence-based phylogenetic analysis

Abstract

Q fever caused by Coxiella burnetii is an important zoonosis and has great public health significance. A total of 905 clinical samples from 387 cattle [serum (n = 387); vaginal swabs (n = 387); milk (n = 131)] and 59 serum samples from humans were collected from gaushala (cattle shelter) and screened for anti-C. burnetii IgG antibodies in the sera using an indirect-ELISA kit. Further, the samples were tested for C. burnetii DNA employing TaqMan real-time and conventional PCR assays targeting the com1 gene. In ELISA, 9.56% and 6.78% of animal and human sera samples were positive for anti-C. burnetii antibodies, respectively. Upon pathogen detection, 3.87% sera, 1.81% vaginal swabs, and 6.87% milk samples from cattle tested positive in TaqMan real-time PCR and 1.55% sera, 0.52% vaginal swabs, and 3.05% milk samples were found positive in conventional PCR. In humans, one serum sample was positive in both the PCR assays. The PCR positive samples (n = 12) were partially sequenced and the phylogenetic tree was constructed using com1 gene sequences (n = 42) from a different host and geographical areas. The study highlights infection of cattle and their human contacts in gaushala and identifies relationships between strains identified in the gaushala and those in other parts of the globe.