Mycoplasma alkalescens is an arginine-metabolizing mycoplasma, which has been found in association with mastitis and arthritis in cattle. Routine bacteriological examination of 17 bronchoalveolar lavage samples from calves with pneumonia in a single herd in Denmark, identified M. alkalescens in eight samples. The organism was found as a sole bacterilogical findings in five of the samples as wel...

The recombinant leukotoxin (rLKT) of the bacterium Pasteurella haemolytica A1 was examined for its ability to protect cattle from experimental challenge with logarithmic-phase P. haemolytica. Six different vaccines were utilized in the experiment: P. haemolytica culture supernatant, P. haemolytica culture supernatant enriched with rLKT, rLKT alone, P. haemolytica culture supernatant enriched wi...

Cell-mediated immune mechanisms may play a role in the pathogenesis and prevention of pneumonia in cattle caused by Pasteurella haemolytica serotype A1. To determine the circumstances required to stimulate and identify cell-mediated immune responses, calves were vaccinated with a commercial P. haemolytica bacterin or a live commercial P. haemolytica vaccine, or were infected intratracheally wit...

Bovine respiratory disease (BRD) is the most important illness of feedlot cattle. Disease management targets the associated bacterial pathogens, Mannheimia haemolytica, Mycoplasma bovis, Pasteurella multocida, Histophilus somni, and Trueperella pyogenes. We conducted a cross-sectional study to measure the frequencies of antimicrobial-resistant BRD pathogens using a collaborative network of vete...

Introduction DRAXXIN contains the active ingredient tulathromycin, the first of a new subclass of macrolide, the triamilides, discovered and developed by Pfizer Animal Health. DRAXXIN is a highly effective, single-dose antimicrobial medication indicated for treatment of BRD, and control of respiratory disease in cattle at high risk of developing BRD, caused by M haemolytica, P multocida and H s...

The in vitro effects of Pasteurella haemolytica components on bovine pulmonary endothelial monolayers were investigated to determine the relative role of individual bacterial factors in the pathogenesis of bovine pulmonary pasteurellosis. Bovine pulmonary endothelial monolayers were treated with P. haemolytica bacterial culture supernatant (CS) and P. haemolytica lipopolysaccharide. At 22 h pos...

Recombinant plasmids coding for a soluble (or surface) antigen of Pasteurella haemolytica A1 were identified. Two plasmids, both containing the same 5.4 kilobase pairs of insert DNA, were recovered independently by screening a clone band of P. haemolytica A1 genomic DNA in Escherichia coli for the expression of P. haemolytica A1 soluble antigens (R. Y. C. Lo and L.A. Cameron, Can. J. Biochem. C...

We have determined the 1.35- and 1.45-A structures, respectively, of closed and open iron-loaded forms of Mannheimia haemolytica ferric ion-binding protein A. M. haemolytica is the causative agent in the economically important and fatal disease of cattle termed shipping fever. The periplasmic iron-binding protein of this gram-negative bacterium, which has homologous counterparts in many other p...

Bovine respiratory disease (BRD) continues to greatly affect beef, dairy, and veal production systems. Vaccination against the bacteria involved is common, yet questions remain regarding efficacy. The purpose of this review was evaluate evidence for effects vaccinating United States or Canadian calves Mannheimia haemolytica, Pasteurella multocida, Histophilus somni on BRD-related morbidity, mor...

Lesions of calf pneumonia caused by Pasteurella haemolytica or P. mu/t,ocida were examined histopathologically using an immunoperoxidase technique for the detection of the bacterial antigen. The results indicated that: 1) multifocal coagulation necrosis sharply demarcated by degenerated leukocytes was a characteristic pulmonary lesion caused by P. haemolytica, 2) other bacteria than P. haemolyt...