title: Bacterial pathogens of the bovine respiratory disease complex.
abstract: Pneumonia caused by the bacterial pathogens discussed in this article is the most significant cause of morbidity and mortality of the BRDC. Most of these infectious bacteria are not capable of inducing significant disease without the presence of other predisposing environmental factors, physiologic stressors, or concurrent infections. Mannheimia haemolytica is the most common and serious of these bacterial agents and is therefore also the most highly characterized. There are other important bacterial pathogens of BRD, such as Pasteurella multocida, Histophulus somni, and Mycoplasma bovis. Mixed infections with these organisms do occur. These pathogens have unique and common virulence factors but the resulting pneumonic lesions may be similar. Although the amount and quality of research associated with BRD has increased, vaccination and therapeutic practices are not fully successful. A greater understanding of the virulence mechanisms of the infecting bacteria and pathogenesis of pneumonia, as well as the characteristics of the organisms that allow tissue persistence, may lead to improved management, therapeutics, and vaccines.
authors.affiliation: Great Plains Veterinary Educational Center, School of Veterinary Medicine and Biomedical Sciences, University of Nebraska - Lincoln, Clay Center, NE 68933-0148, USA. dgriffin@gpvec.unl.edu
authors.forename: Dee
authors.initials: D
authors.lastname: Griffin
authors.forename: M M
authors.initials: MM
authors.lastname: Chengappa
authors.forename: Jennifer
authors.initials: J
authors.lastname: Kuszak
authors.forename: D Scott
authors.initials: DS
authors.lastname: McVey
mesh_terms: D000818:Animals; D048090:Bovine Respiratory Disease Complex / Q000453:epidemiology / Q000382:microbiology*; D002417:Cattle; D005260:Female; D008297:Male; D016978:Mannheimia haemolytica; D009175:Mycoplasma Infections / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary; D045682:Mycoplasma bovis; D010326:Pasteurella Infections / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary; D016979:Pasteurella multocida; D048089:Pneumonia of Calves, Enzootic / Q000453:epidemiology / Q000382:microbiology; D018410:Pneumonia, Bacterial / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*; D014774:Virulence