Virulence of Bordetella Bronchiseptica in the Porcine Respiratory Tract

• Published in: Journal of medical microbiology Vol. 19; no. 2; pp. 247 - 255
• Main Authors: Collings, Louise A, Rutter, J. M
• Format: Journal Article
• Language: English
• Published: Reading Soc General Microbiol 01.04.1985; Society for General Microbiology
• Subjects: Animals; Antibodies, Bacterial - biosynthesis; Atrophy; Bacterial diseases; Bacterial Toxins - biosynthesis; Biological and medical sciences; Bordetella - growth & development; Bordetella - immunology; Bordetella - isolation & purification; Bordetella - pathogenicity; Bordetella Infections - microbiology; Bordetella Infections - pathology; Cattle; Cell Line; Experimental bacterial diseases and models; Fimbriae, Bacterial - ultrastructure; Germ-Free Life; Hemagglutination; Infectious diseases; Medical sciences; Nasal Cavity - microbiology; Respiratory System - microbiology; Respiratory Tract Infections - microbiology; Swine; Turbinates - pathology; Virulence; Gnotobiotic animal; Respiratory disease; Virulence; Turbinate bone; Pig; Infection; Respiratory tract; Bordetella bronchiseptica; Toxin; Vertebrata; Experimental disease; Mammalia; Newborn animal; Production; Atrophia; Bacteriosis; Bacteria; Artiodactyla; Ungulata; Colonization
• DOI: 10.1099/00222615-19-2-247
• ISSN: 0022-2615

Agricultural and Food Research Council, Institute for Research on Animal Diseases, Compton, Newbury, Berkshire RG16 0NN Received May 30, 1984 Accepted July 13, 1984 The virulence of Bordetella bronchiseptica in gnotobiotic piglets was studied by intranasal infection with 11 cultures derived from eight strains isolated from pigs (4), dogs (2), a human subject and a monkey. Six of the cultures contained organisms in phase I and five contained phenotypically different phase-III or -IV organisms. Of the phase-III and -IV cultures, four were derived from strains that had been isolated in phase I. Colonisation of the nasal cavity was investigated by counting bacteria in nasal swabs and washings. The toxigenicity of cell extracts from each strain and variant was determined by tests of lethality in mice or of cytopathogenicity in cell cultures. The results showed that two phase-I cultures from pigs colonised the nasal cavity and respiratory tract of gnotobiotic piglets better than did four phase-I cultures from other species. Phase-I organisms invariably produced capsules, fimbriae and mannose-resistant haemagglutination of guinea-pig erythrocytes. Four of five cultures in phases III and IV consisted of organisms that did not produce capsules, fimbriae or haemagglutination and colonised the nasal cavity poorly. Phase variation from I to III occurred in culture and in vivo , but variation from III to I occurred in vivo only and was accompanied by enhanced colonisation. Gnotobiotic piglets infected with porcine phase-I organisms exhibited atrophy of the nasal turbinate bones after 28 days; these organisms produced significantly more toxin than did bacteria in phase I from other species, or those in phases III and IV. It was concluded that the development of turbinate atrophy was associated with (1) the ability to produce heavy, persistent colonisation in the nasal cavity, and (2) the production of a heat-labile toxin. Only the two porcine phase-I cultures possessed both properties. * Present address: Royal Free Hospital School of Medicine, Hampstead, London NW3.