Pasteurella multocidaand bovine respiratory disease

Abstract

Pasteurella multocida is a pathogenic Gram-negative bacterium that has been classified into three subspecies, five capsular serogroups and 16 serotypes. P. multocida serogroup A isolates are bovine nasopharyngeal commensals, bovine pathogens and common isolates from bovine respiratory disease (BRD), both enzootic calf pneumonia of young dairy calves and shipping fever of weaned, stressed beef cattle. P. multocida A:3 is the most common serotype isolated from BRD, and these isolates have limited heterogeneity based on outer membrane protein (OMP) profiles and ribotyping. Development of P. multocida-induced pneumonia is associated with environmental and stress factors such as shipping, co-mingling, and overcrowding as well as concurrent or predisposing viral or bacterial infections. Lung lesions consist of an acute to subacute bronchopneumonia that may or may not have an associated pleuritis. Numerous virulence or potential virulence factors have been described for bovine respiratory isolates including adherence and colonization factors, iron-regulated and acquisition proteins, extracellular enzymes such as neuraminidase, lipopolysaccharide, polysaccharide capsule and a variety of OMPs. Immunity of cattle against respiratory pasteurellosis is poorly understood; however, high serum antibodies to OMPs appear to be important for enhancing resistance to the bacterium. Currently available P. multocida vaccines for use in cattle are predominately traditional bacterins and a live streptomycin-dependent mutant. The field efficacy of these vaccines is not well documented in the literature.

Pathogens of Bovine Respiratory Disease in North American Feedlots Conferring Multidrug Resistance via Integrative Conjugative Elements

“…It is also possible those data are a result of the restricted sample size, a limitation of the PCR to identify cattle infected with multiple strains of BVDV, or the result of the use of BVDV2-based modified live vaccines in Alberta but not U.S. feedlots. Compared to previous investigations (23,27), the occurrence of P. multocida was lower than anticipated, but it is acknowledged that P. multocida plays a significant role in dairy calf pneumonia and in subacute/chronic bronchopneumonia (28,29) and less of a role in acute fibrinous pneumonia in feedlot calves. Despite selection for fibrinous pneumonia cases, M. bovis and H. somni were isolated at higher rates than expected, comparable to those detected in chronic and bronchiolar pneumonia cases in Alberta (4).…”

Pasteurella multocida: from Zoonosis to Cellular Microbiology

“…P. multocida is a common commensal or opportunistic pathogen found in the upper respiratory tracts of most livestock, domestic, and wild animals (34), including chickens (126)(127)(128)(129)(130)(131), turkeys (132,133), and other wild birds (123,(134)(135)(136)(137)(138)(139)(140)(141)(142)(143)(144), cattle and bison (121,(145)(146)(147), swine (34, 148-151), rabbits (152)(153)(154), dogs (41, [155][156][157], cats (domestic house cats as well as large wild cats, such as tigers, leopards, cougars, and lions) (39, 42-46, 49, 157-166), goats (125,139,167,168), chimpanzees (169), marine mammals (seals, sea lions, and walruses) (170), and even komodo dragons (171,172). The manifestation and pathological symptoms associated with Pasteurella infection, or "pasteurellosis," range from asymptomatic or mild chronic upper respiratory inflammation to acute, often fatal, pneumonic and/or disseminated disease.…”

Manejo do complexo respiratório bovino em confinamento: Revisão

“…Em bezerros sadios, a presença desse agente está entre 20 -60% (Dabo et al, 2007). Essa alta taxa de isolamento permite afirmar que a bactéria é comensal do trato respiratório superior dos bovinos, e para correlacionar esta bactéria como o agente causal do CRB, é necessário mais que o dobro do isolamento em comparado com animais sem sinais clínicos Forsberg, 2007, Dabo et al, 2007).…”