Ab. Magnusdottir et al., Experimental study of the virulence of Streptococcus pneumoniae with reduced susceptibility to penicillin, INT J PED O, 55(1), 2000, pp. 1-9
Citations number
39
Categorie Soggetti
Otolaryngology
Journal title
INTERNATIONAL JOURNAL OF PEDIATRIC OTORHINOLARYNGOLOGY
Streptococcus pneumoniae is a major cause of morbidity and mortality in all
age groups. In a few years, penicillin non-susceptible pneumococci (PNSP)
have emerged worldwide as a new threat. In order to better understand the m
echanisms behind the rapid expansion of these strains, the virulence of 10
clinical and two transformed PNSP strains were compared with the virulence
of three fully susceptible strains in a mouse model of bacteremia and a rat
model of acute otitis media. Serotype, antibiotic susceptibility, and to s
ome extent also genetic profile and growth rate of the strains were investi
gated before inoculation. The animals were monitored for up to 7 days after
challenge by clinical examinations/otomicroscopy and cultures from middle
ears and blood. The results of the study demonstrated that the PNSP strains
had a significantly reduced ability to persist at the infectious site, and
to some extent also to induce infections, compared with fully susceptible
strains. The reduction was most evident for strains isolated from sources o
ther than blood. It is therefore possible that other factors than virulence
factors are of importance for the ability of PNSP strains to expand. (C) 2
000 Elsevier Science Ireland Ltd. All rights reserved.