VIRULENCE OF SALMONELLA-ENTERITIDIS PHAGETYPE-4, PHAGETYPE-8 AND PHAGETYPE-13 AND OTHER SALMONELLA SPP FOR DAY-OLD CHICKS, HENS AND MICE

Virulence of three Canadian poultry strains of Salmonella enteritidis, namely phagetypes (PT) 4, 8 and 13, and one Salmonella heidelberg str ain was assessed in orally and intraperitoneally inoculated one-day ol d chickens and compared to the virulence of a human S. enteritidis PT 4 strain from the United Kingdom (UK). The two PT 4 strains were also compared in orally inoculated adult laving hens. In addition, orally i noculated Balb/c mice were used to evaluate virulence of the above str ains and two strains of Salmonella typhimurium containing different pl asmids. In orally inoculated one-day old chickens, the UK S. enteritid is PT 4 strain was more virulent than the Canadian PT 4 strain. The UK PT 4 strain was also more virulent and invasive in adult laying hens than the Canadian PT 4 strain. The S. enteritidis PT 8 strain and one S. typhimurium strain isolated from a chicken hatchery were the most v irulent for orally inoculated Balb/c mice. This strain of S. typhimuri um contained the 60 megadalton plasmid associated with virulence for B alb/c mice which was not present in the S. typhimurium strain isolated from a pig with septicemic disease.