[Virulence of stable strains of Klebsiella pneumoniae in the white mouse].
In 65 stable strains of K. pneumoniae, nine of which originated from acute parenchymatous mastitis of cattle and 56 from milk, nasal mucus, skin from the udder base and from the rectal contents of clinically healthy dairy cows, the virulence for white mice was studied. The achieved results were as follows: (1) At 1 ml dose of the 24-hr. broth culture i. p., 51 strains (78.4%) were virulent, at 2 ml dose 56 strains (86.1%). The percentage of the strains from milk and from the rectal contents of the clinically healthy dairy cows was approximately the same, whereas the strains from acute parenchymatous mastitis and skin were virulent in the full extent. (2) The influence of the growth phase and of the presence of microbial capsule was not marked because both in the capsuled and in the uncapsuled strains the lethal doses amounted to 0.2 to 2.0 ml, however, in both groups also the completely harmless strains were detected. In a detailed evaluation it is necessary to take into consideration that in the capsuled strains (49) the lethal doses amounted to 0.5 ml (50% of all cases) and in the uncapsuled to 1 ml (43.7% of all cases). (3) Necrotoxin test showed that 18 strains (27.7%) caused local skin inflammation in the rabbit, lasting 3 to 6 days and characterized by skin reddening and swelling (diameter 1.5 to 2.0 cm). This finding is in direct correlation with the death of experimental mice but not with the lethal doses and time of exitus; in both cases 0.2 to 2.0 ml doses were applied and the animals died one to three days after inoculation.
D000818:Animals; D002417:Cattle / Q000382:microbiology*; D007711:Klebsiella pneumoniae / Q000302:isolation & purification / Q000472:pathogenicity*; D051379:Mice; D014774:Virulence
Virulence stájových kmenů Klebsiella pneumoniae pro bílou mys.