Related Experiment Videos
Haemophilus influenzae type b strains of outer membrane subtypes 1 and 1c cause different types of invasive disease
Abstract:
Of 275 consecutive Haemophilus influenzae type b (Hib) strains isolated from children with invasive disease in Finland in 1985-86, 74% were of the common European outer membrane protein (OMP) subtype 1 and 22% were of OMP subtype 1c, which is usually rare. Strains of subtype 1c caused proportionately more meningitis and less epiglottis than did strains of subtype 1c. Furthermore, children with disease due to strains of subtype 1c were younger than those with disease due to strains of subtype 1. The significant difference in association between subtype and the diagnosis of epiglottitis or meningitis remained even when the strong influence of age was accounted for. This finding may suggest a true difference in the virulence between these subtypes not previously demonstrated for Haemophilus influenzae type b.
Insights
Certain Haemophilus influenzae type b (Hib) strains, particularly OMP subtype 1c, were linked to more severe invasive diseases like meningitis in children. This suggests potential differences in virulence between Hib subtypes.
Area of Science:
- Microbiology
- Epidemiology
- Pediatrics
Background:
- Haemophilus influenzae type b (Hib) is a major cause of invasive bacterial disease in children.
- Outer membrane protein (OMP) subtypes of Hib may exhibit different pathogenic potentials.
Purpose of the Study:
- To investigate the association between Hib OMP subtypes and clinical presentation of invasive disease.
- To determine if specific OMP subtypes are linked to increased risk of meningitis or epiglottitis.
Main Methods:
- Analysis of 275 invasive Hib strains from children in Finland (1985-86).
- Characterization of strains by OMP subtype (predominantly subtype 1 and subtype 1c).
- Statistical analysis correlating OMP subtype with disease diagnosis and patient age.
Main Results:
- A higher proportion of OMP subtype 1c strains were isolated compared to usual prevalence.
- OMP subtype 1c strains were disproportionately associated with meningitis and less with epiglottitis.
- Children with OMP subtype 1c-associated disease were younger, and this association persisted after age adjustment.
Conclusions:
- OMP subtype 1c of Haemophilus influenzae type b may possess distinct virulence characteristics.
- These findings suggest a potential for subtype-specific differences in disease causation and severity for Hib infections.