Invasive disease due to nontypeable Haemophilus influenzae among children in Arkansas.
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.
O'Neill
Joshua M
JM
Department of Pediatrics, University of Arkansas for Medical Sciences/Arkansas Children's Hospital, Little Rock, Arkansas, USA. ONeillJoshua@uams.edu
St  Geme
Joseph W
JW
Cutter
David
D
Adderson
Elisabeth E
EE
Anyanwu
Juliana
J
Jacobs
Richard F
RF
Schutze
Gordon E
GE
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
D001426:Bacterial Proteins