title: Invasive disease due to nontypeable Haemophilus influenzae among children in Arkansas.
abstract: In this study, we reviewed cases of invasive disease due to nontypeable Haemophilus influenzae among children hospitalized at Arkansas Children's Hospital from 1993 to 2001. A total of 28 cases were examined, including 21 associated with bacteremia and 4 associated with meningitis. Of the patients examined, 86% were </=4 years of age, and 68% had underlying medical conditions. Characterization of the bacterial isolates by multilocus sequence type genotyping revealed significant overall genetic diversity, similar to the diversity in the general population structure for nontypeable H. influenzae. However, four separate pairs of isolates were closely related genetically, a relationship confirmed by pulsed-field gel electrophoresis and Southern hybridization studies using probes for the major H. influenzae adhesin genes. These results suggest that selected strains of nontypeable H. influenzae may have more invasive potential, especially in young children and patients with underlying medical conditions. At this point, the specific factors that contribute to enhanced virulence remain unclear.
authors.affiliation: Department of Pediatrics, University of Arkansas for Medical Sciences/Arkansas Children's Hospital, Little Rock, Arkansas, USA. ONeillJoshua@uams.edu
authors.forename: Joshua M
authors.initials: JM
authors.lastname: O'Neill
authors.forename: Joseph W
authors.initials: JW
authors.lastname: St  Geme
authors.forename: David
authors.initials: D
authors.lastname: Cutter
authors.forename: Elisabeth E
authors.initials: EE
authors.lastname: Adderson
authors.forename: Juliana
authors.initials: J
authors.lastname: Anyanwu
authors.forename: Richard F
authors.initials: RF
authors.lastname: Jacobs
authors.forename: Gordon E
authors.initials: GE
authors.lastname: Schutze
mesh_terms: D000293:Adolescent; D001131:Arkansas / Q000453:epidemiology; D016470:Bacteremia / Q000453:epidemiology* / Q000382:microbiology; D001426:Bacterial Proteins / Q000235:genetics; D015139:Blotting, Southern; D002648:Child; D002675:Child, Preschool; D016521:Electrophoresis, Gel, Pulsed-Field; D005260:Female; D014644:Genetic Variation; D005838:Genotype; D006192:Haemophilus Infections / Q000453:epidemiology* / Q000382:microbiology; D006193:Haemophilus influenzae / Q000145:classification* / Q000235:genetics*; D006760:Hospitalization; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D017422:Sequence Analysis, DNA
chemical_list: D001426:Bacterial Proteins