[Staphylococcus aureus infection in chickens in industrialized poultry units. 2. Microbiological studies:...

Checks were applied to 3,213 dead or ill broiler chickens and broiler parents for the purpose of elucidating enzootic or epizootic Staphylococcus aureus infections which had occurred on three industrialised poultry units. Rates of Staphylococcus aureus detection and identification declined by the following order: staphylococcal septicaemia (100 per cent), dermatitis (75.42 per cent), arthritis and tenosynovitis or osteomyelitis (64.59 per cent), wound infections (24.02 per cent), infection of bursa suprasternalis (18.94 per cent), underdevelopment (8.70 per cent), navel-yolksac-peritonitis (7.83 per cent), and conjunctivitis (7.14 per cent). Staphylococcus aureus was found to be the most important pathogen of arthritis with synovitis and of osteomyelitis with epiphysiolysis, the rate of detection being directly correlated with the severity of the pathologico-anatomic alterations established. Attempts to culture mycoplasmas from irritated synovial sheaths were successful only in three of 56 examined animals (5.3 per cent). The site variety of gallinae or strains of the crystal-violet Type A with lysis patterns of 84, 53, 77 and 84 accounted for 78.1 per cent of all Staphylococcus aureus strains isolated from infected fowl. Their percentual importance was 85.0 for septicaemia, dermatitis, and arthritis with synovitis and osteomyelitis. For prophylaxis and control of Staphylococcus aureus infections of fowl on elimination of predisposing factors and on the control of epidemic occurrence of the above types.