Abstract:
For 73 bacterial strains, represented by Proteus vulgaris (21 strains), Escherichia
coli (29), Staphilococus aureus (29) and Salmonella typhimurium (5), isolated from embryos
and chickens dead after hatching, we have determined in vivo pathogenicity. The culture
medium incubated for 24 hours was inoculated intraperitoneally in mice. From the 73
bacterial strains, 52 of them (65.77%) proved to be pathogenic, which killed mice, according
to the bacterial strain, during 18-72 hours, while 25 strains (34.23%) were not pathogenic. In
some bacterial strains without pathogenicity, inoculated in mixture (Proteus vulgaris +
Escherichia coli and Proteus + Staphilococcus aureus), we noticed a synergic reaction
expressed through pathogenicity in mice.