Usage Information
Citation Information: J Clin Invest. 1984;73(2):298-306. https://doi.org/10.1172/JCI111214.
Abstract
Haemophilus influenzae may make any one of six chemically distinct capsular polysaccharides, but only strains of capsular serotype b commonly cause systemic infection (e.g., meningitis) in humans. Molecular cloning of DNA was used to investigate the expression of type b capsule and its association with H. influenzae virulence. A virulent H. influenzae type b strain was used to construct a lambda library of chromosomal DNA in Charon 4. Two independently isolated recombinant phage were isolated from the library and were found to possess DNA necessary for expression of type b capsule. Using a well-characterized rat model of H. influenzae systemic infection, we showed that type b transformants elicited by the cloned DNA were pathogenic, causing bacteremia and meningitis, whereas the untransformed capsule-deficient H. influenzae organisms were not. A 4.4-kb EcoRI fragment, common to both DNA clones, was used to characterize clinical isolates representing all six encapsulated serotypes as well as several capsule-deficient H. influenzae by Southern hybridization analysis. The probe hybridized to an identical sized (4.4 kb) fragment of EcoRI-digested chromosomal DNA from eight independently isolated type b strains. Single bands of homology to the probe were also found in EcoRI fragments of chromosomal DNA obtained from 33 encapsulated, nontype b H. influenzae. However, the size of these EcoRI fragments proved to be characteristic for each of the different capsular serotypes. These studies provide a basis for pursuing the molecular analysis of the epidemiology and virulence of pathogenic H. influenzae.
Authors
E R Moxon, R A Deich, C Connelly
Usage data is cumulative from July 2024 through July 2025.
| Usage | JCI | PMC |
|---|---|---|
| Text version | 162 | 4 |
| 53 | 15 | |
| Figure | 0 | 1 |
| Scanned page | 419 | 3 |
| Citation downloads | 74 | 0 |
| Totals | 708 | 23 |
| Total Views | 731 | |
Usage information is collected from two different sources: this site (JCI) and Pubmed Central (PMC). JCI information (compiled daily) shows human readership based on methods we employ to screen out robotic usage. PMC information (aggregated monthly) is also similarly screened of robotic usage.
Various methods are used to distinguish robotic usage. For example, Google automatically scans articles to add to its search index and identifies itself as robotic; other services might not clearly identify themselves as robotic, or they are new or unknown as robotic. Because this activity can be misinterpreted as human readership, data may be re-processed periodically to reflect an improved understanding of robotic activity. Because of these factors, readers should consider usage information illustrative but subject to change.
Copyright © 2025 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)