Pathologic Lesions Caused by Coinfection of Mycoplasma gallisepticum and H3N8 Low Pathogenic Avian Influenza Virus in Chickens

• Published in: Veterinary pathology Vol. 49; no. 2; pp. 273 - 283
• Main Authors: Stipkovits, L., Glavits, R., Palfi, V., Beres, A., Egyed, L., Denes, B., Somogyi, M., Szathmary, S.
• Format: Journal Article
• Language: English
• Published: Los Angeles, CA SAGE Publications 01-03-2012
• Subjects: Animals; Antibodies, Bacterial - biosynthesis; Antibodies, Bacterial - blood; Antibodies, Viral - biosynthesis; Antibodies, Viral - blood; Avian influenza virus; Bronchitis - microbiology; Bronchitis - pathology; Bronchitis - veterinary; Bronchitis - virology; Chickens; Coinfection; Hungary; Influenza A Virus, H3N8 Subtype - immunology; Influenza A Virus, H3N8 Subtype - pathogenicity; Influenza in Birds - complications; Influenza in Birds - pathology; Influenza virus; Motion Sickness - veterinary; Mycoplasma; Mycoplasma gallisepticum; Mycoplasma gallisepticum - immunology; Mycoplasma gallisepticum - pathogenicity; Mycoplasma Infections - complications; Mycoplasma Infections - pathology; Mycoplasma Infections - veterinary; Pneumonia - microbiology; Pneumonia - pathology; Pneumonia - veterinary; Pneumonia - virology; Poultry Diseases - microbiology; Poultry Diseases - pathology; Poultry Diseases - virology; Respiratory Mucosa - pathology; Specific Pathogen-Free Organisms; Trachea - pathology; Tracheitis - microbiology; Tracheitis - pathology; Tracheitis - veterinary; Tracheitis - virology; Virulence; Weight Gain; Hungary; infectious; poultry; viral; bacterial; respiratory; immunologic/inflammation
• ISSN: 0300-9858; 1544-2217
• DOI: 10.1177/0300985811415702

Chickens were infected under experimental conditions with Mycoplasma gallisepticum and low pathogenic avian influenza (LPAI) strain A/mallard/Hungary/19616/07 (H3N8). Two groups of chickens were aerosol challenged with M. gallisepticum strain 1226. Seven days later, one of these groups and one mycoplasma-free group was challenged with LPAI H3N8 virus; one group without challenge remained as negative control. Eight days later, the birds were euthanized and examined for gross pathologic and histologic lesions. The body weight was measured, and the presence of antimycoplasma and antiviral antibodies was tested before the mycoplasma challenge, before the virus challenge, and at the end of the study to confirm both infections. Chickens in the mycoplasma-infected group developed antibodies against M. gallisepticum but not against the influenza virus. Chickens of the group infected with the influenza virus became serologically positive only against the virus, while the birds in the coinfected group developed antibodies against both agents. The LPAI H3N8 virus strain did not cause decrease in body weight and clinical signs, and macroscopic pathological lesions were not present in the chickens. The M. gallisepticum infection caused respiratory signs, airsacculitis, and peritonitis characteristic of mycoplasma infection. However, the clinical signs and pathologic lesions and the reduction in weight gain were much more significant in the group challenged with both M. gallisepticum and LPAI H3N8 virus than in the group challenged with M. gallisepticum alone.