Partial analysis of the genomes of two nontypeable Haemophilus influenzae otitis media isolates.
In 1995, The Institute for Genomic Research completed the genomic sequence of a rough derivative of Haemophilus influenzae serotype d, strain KW20. This sequence, though extremely useful in understanding the basic biology of H. influenzae, has yet to provide significant insight into our understanding of disease caused by nontypeable H. influenzae (NTHI), because serotype d strains are not generally pathogens. In contrast, NTHI strains are frequently mucosal pathogens and are the primary pathogens of chronic otitis media as well as a significant cause of acute otitis media in children. Thus, it is of great importance to further understand their biology. We used a DNA-based microarray approach to identify genes present in a clinical isolate of NTHI that were absent from strain Rd. We also sequenced the genome of a second NTHI isolate from a child with chronic otitis media to threefold coverage and then used an array of bioinformatics tools to identify genes present in this NTHI strain but absent from strain Rd. These methods were complementary in approach and results. We identified, in both strains, homologues of H. influenzae lav, an autotransported protein of unknown function; tnaA, which encodes tryptophanase; as well as a homologue of Pasteurella multocida tsaA, which encodes an alkyl peroxidase that may play a role in protection against reactive oxygen species. We also identified a number of putative restriction-modification systems, bacteriophage genes and transposon-related genes. These data provide new insight that complements and extends our ongoing analysis of NTHI virulence determinants.
Munson
Robert S
RS
Center for Microbial Pathogenesis, Columbus Children's Research Institute and The Department of Pediatrics, The Ohio State University, Columbus, Ohio 43205, USA. munsonr@pediatrics.ohio-state.edu
Harrison
Alistair
A
Gillaspy
Allison
A
Ray
William C
WC
Carson
Matt
M
Armbruster
David
D
Gipson
Jenny
J
Gipson
Mandy
M
Johnson
Linda
L
Lewis
Lisa
L
Dyer
David W
DW
Bakaletz
Lauren O
LO
D001426:Bacterial Proteins / Q000235:genetics; D002648:Child; D005798:Genes, Bacterial; D016680:Genome, Bacterial; D006192:Haemophilus Infections / Q000382:microbiology*; D006193:Haemophilus influenzae / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification* / Q000472:pathogenicity; D006801:Humans; D020411:Oligonucleotide Array Sequence Analysis; D010033:Otitis Media / Q000382:microbiology*; D013045:Species Specificity; D014774:Virulence / Q000235:genetics
D001426:Bacterial Proteins