Abstract
Surface structures in Haemophilus influenzae are subject to rapid ON/OFF switching of expression, a process termed phase variation. We analyse tetranucleotide repeats controlling phase variation in lipo-oligosaccharide (LOS) genes of H. influenzae in paired isolates from both the nasopharynx and middle ears of paediatric patients with chronic or recurrent otitis media. A change in expression of at least one of the seven phase variable LOS biosynthesis genes was seen in 12 of the 21 strain pairs. Several strains showed switching of expression in multiple LOS genes, consistent with a key role for phase variable LOS biosynthetic genes in human infection.
Publication types
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Research Support, N.I.H., Extramural
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Research Support, Non-U.S. Gov't
MeSH terms
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Bacterial Proteins / genetics
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Bacterial Proteins / metabolism*
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Biosynthetic Pathways / genetics
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Child
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DNA, Bacterial / chemistry
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DNA, Bacterial / genetics
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Disease Progression
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Ear, Middle / microbiology*
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Haemophilus Infections / microbiology*
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Haemophilus Infections / pathology
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Haemophilus influenzae / genetics
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Haemophilus influenzae / isolation & purification
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Haemophilus influenzae / physiology*
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Humans
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Lipopolysaccharides / biosynthesis*
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Nasopharynx / microbiology*
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Otitis Media / microbiology
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Otitis Media / pathology
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Sequence Analysis, DNA
Substances
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Bacterial Proteins
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DNA, Bacterial
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Lipopolysaccharides