Evaluate Coxiella burnetii dynamics in a naturally infected goat herd over three kidding seasons, as well as its influence on the caprine and environmental microbiota during two kidding seasons following Q fever vaccination implementation
Q fever is a zoonotic disease with major implications for the small ruminant sector, particularly in goat herds. Despite vaccination is the main control strategy, there is limited evidence assessing whole-herd vaccine effects on pathogen shedding, seroconversion, and any about the associated microbiota over time. A total of 18 females (aborted and normal-delivery) and two bucks were included from a natural-infected herd after a clinical outbreak.  Sampling points were defined: T0, first week post-abortion or delivery; T1, two months post-primary vaccination; T2, first week after delivery, 300 days after primary vaccination and before revaccination; T3, first week after delivery, nine months after revaccination (second year of vaccination). Faeces, milk, vaginal/preputial swabs, blood, and environmental samples were analyzed by q-PCR and 16S rRNA sequencing. Serology was also performed. At T0, > 70% of animals were seropositive, with full seroconversion by T1?T2, and ~90 % at T3, supporting the need for sustained vaccination to prevent reinfection. C. burnetii was detected only at T0 and T1, in 100% of females and 50% of bucks at T0. Despite no significant differences between female groups, vaccination significantly reduced overall detection rates by 60% (P < 0.0001). Nasal samples showed the highest (T0 and T1) and most persistent positivity (T1), suggesting under evaluated respiratory tropism and potential for enhanced diagnostic sensitivity. In males, C. burnetii was detected in preputial samples, underscoring their role in disease maintenance and the need to include them in control programs. Environmental contamination persisted until T1, with new potential sources identified (milking machine and domestic animals), highlighting hygiene gaps. Metagenomic analyses revealed, for the first time, significant differences in the microbial diversity between females and anatomical locations over time. Specifically, despite vaginal diversity at T0 did not differ between female groups, at T1 different bacterial community structure in vaginal microbiota between both female?s groups was observed (P < 0.05), suggesting systemic microbiota disruption irrespective of abortion history. After vaccination (T1?T2), Firmicutes dominance was observed, alongside increases in Alistipes and Akkermansia in faeces, Lactococcus and Acinetobacter in milk, and decreased Fusobacterium in vagina, may as an indicative of microbiota restoration. Additionally, this is the first report of C. burnetii detection in blood and nasal samples of clinically affected goats by metabarcoding. A significant reduction in vaginal pathogen abundance (P < 0.05) at T1 suggests a modulation of reproductive microbiota.
Q fever is a zoonotic disease with major implications for the small ruminant sector, particularly in goat herds. Despite vaccination is the main control strategy, there is limited evidence assessing whole-herd vaccine effects on pathogen shedding, seroconversion, and any about the associated microbiota over time. A total of 18 females (aborted and normal-delivery) and two bucks were included from a natural-infected herd after a clinical outbreak.  Sampling points were defined: T0, first week post-abortion or delivery; T1, two months post-primary vaccination; T2, first week after delivery, 300 days after primary vaccination and before revaccination; T3, first week after delivery, nine months after revaccination (second year of vaccination). Faeces, milk, vaginal/preputial swabs, blood, and environmental samples were analyzed by q-PCR and 16S rRNA sequencing. Serology was also performed. At T0, > 70% of animals were seropositive, with full seroconversion by T1?T2, and ~90 % at T3, supporting the need for sustained vaccination to prevent reinfection. C. burnetii was detected only at T0 and T1, in 100% of females and 50% of bucks at T0. Despite no significant differences between female groups, vaccination significantly reduced overall detection rates by 60% (P < 0.0001). Nasal samples showed the highest (T0 and T1) and most persistent positivity (T1), suggesting under evaluated respiratory tropism and potential for enhanced diagnostic sensitivity. In males, C. burnetii was detected in preputial samples, underscoring their role in disease maintenance and the need to include them in control programs. Environmental contamination persisted until T1, with new potential sources identified (milking machine and domestic animals), highlighting hygiene gaps. Metagenomic analyses revealed, for the first time, significant differences in the microbial diversity between females and anatomical locations over time. Specifically, despite vaginal diversity at T0 did not differ between female groups, at T1 different bacterial community structure in vaginal microbiota between both female?s groups was observed (P < 0.05), suggesting systemic microbiota disruption irrespective of abortion history. After vaccination (T1?T2), Firmicutes dominance was observed, alongside increases in Alistipes and Akkermansia in faeces, Lactococcus and Acinetobacter in milk, and decreased Fusobacterium in vagina, may as an indicative of microbiota restoration. Additionally, this is the first report of C. burnetii detection in blood and nasal samples of clinically affected goats by metabarcoding. A significant reduction in vaginal pathogen abundance (P < 0.05) at T1 suggests a modulation of reproductive microbiota.
Microomics Systems S.L.