Genetic transformation in encapsulated clinical isolates of Haemophilus influenzae type b.
Haemophilus influenzae type b strains isolated from children with meningitis, septicaemia and pharyngitis were studied for their ability to undergo genetic transformation by two chromosomal markers, streptomycin resistance and nalidixic acid resistance. Fifty-eight percent of the strains were non-transformable while the remaining 42% showed considerable strain variation with regard to their transformation frequencies, which ranged from 8 x 10(-4) to 1 x 10(-6). The effect of type b capsule on competence development and transformation activity was studied by comparing encapsulated strains with their non-encapsulated variants. Type b capsule did not inhibit either competence development or transforming efficiency. The lack of transformability in the majority of strains was not due to the presence of a capsule.
Rowji
P
P
Emergent Pathogen Research Unit, South African Medical Research Council, School of Pathology, University of Witwatersrand.
Gromkova
R
R
Koornhof
H
H
D002462:Cell Membrane / Q000648:ultrastructure; D002648:Child; D004352:Drug Resistance, Microbial / Q000235:genetics; D006192:Haemophilus Infections / Q000382:microbiology; D006193:Haemophilus influenzae / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D008583:Meningitis, Haemophilus / Q000382:microbiology; D010612:Pharyngitis / Q000382:microbiology; D018805:Sepsis / Q000382:microbiology; D013045:Species Specificity; D014170:Transformation, Genetic