Airways and gut microbiome disturbance and resilience dynamics during polymicrobial bovine respiratory disease
Résumé
Bovine respiratory disease (BRD) is a significant health issue in cattle populations, and understanding its impact on the gut-lung axis’s temporal dynamics is crucial. In this longitudinal study, we examined the nasopharyngeal and gastrointestinal microbiota of 30 calves aged from 7 days to 5 months to identify the microbial patterns associated with BRD across varying degrees of disease severity. Our findings revealed the presence of pathogenic entities such as Mycoplasma bovis, Mannheimia haemolytica, Pasteurella multocida, Histophilus somni, and viruses including IDV, BRSV, BPIV3, and BCoV within the respiratory tract of both symptomatic and asymptomatic calves during the initial 15-day period. This phase was marked by significant fluctuations in respiratory and gut bacterial ecosystems. Notably, we found that elevated loads of Mycoplasma bovis and BCoV were statistically correlated with disrupted airway microbiomes in calves exhibiting early symptoms. After 30 days of life, both the respiratory and gastrointestinal microbiomes of infected and non-infected subjects displayed stable ecostate communities, consistent intra- and inter-individually. These findings underscore the dynamism and resilience of the airways and gut microbiome amidst polymicrobial challenges and the critical importance of microbiome homeostasis. The potential for preserving this balance early in age to preempt viral and bacterial co-infections in bovine populations is a promising therapeutic avenue, with significant implications for the management of BRD.