[Colibacillosis in poultry: etiology, pathology and therapy]

Colibacillosis is a secondary infection caused by inhalation, particularly in young broilers and poults. The severity of this septicaemic disease is due to a combination of factors as the virulence, exposure to aerogenic infection, the E. coli strains involved and the intensity of the predisposing alteration of the respiratory epithelium by viruses. Mycoplasmas and/or CO2, NH3 and dust in the atmosphere. Despite preventive vaccination against several predisposing viral infections and the successful eradication of M. gallisepticum in the Netherlands, colibacillosis continues to be an important disease in the broiler industry. Treatment is confronted with a number of serious problems: high costs when treating flocks with the correct (relatively high) dosage for a sufficiently long period, resistance to bacterial drugs and drug residues. Despite negligible resorption from the gastrointestinal tract, very satisfactory therapeutic results were obtained by oral treatment, even against in vitro resistant E. colli strains. To explain the mode of action it is suggested that well-absorbed metabolites or degradation products of spectinomycin block the adhesion of bacteria to tissue receptors.