Pasteurella

Bacteria from the genus Pasteurella are common mucosal commensals present in the upper respiratory tract of a range of animals. Toxigenic P. multocida are a unique subset of strains that produce a toxin called Pasteurella multocida toxin, which is the causative agent of atrophic rhinitis in pigs and rabbits. P. multocida encounters a wide range of niches and stresses during infection and this requires precise regulation of virulence factors, nutrient acquisition processes, and stress responses. Several regulators have been identified in P. multocida including the transcriptional regulators, ferric uptake regulator and factor for inversion stimulation, the RNA chaperone Hfq, and the associated small RNA GcvB. The immediate host response to an invading Gram-negative extracellular pathogen usually involves the action of phagocytic cells, the upregulation of inflammatory cytokines and the production of antimicrobial peptides, and stimulation of the alternative complement pathway.