You are here: Home Published Research Phylogenetic relatedness and diversity of non-typable Haemophilus influenzae in the nasopharynx and middle ear fluid of children with acute otitis media.

Ravinder Kaur, Arthur Chang, Qingfu Xu, Janet R Casey, and Michael E Pichichero (2011)

Phylogenetic relatedness and diversity of non-typable Haemophilus influenzae in the nasopharynx and middle ear fluid of children with acute otitis media.

Journal of medical microbiology, 60(Pt 12):1841–1848.

The phylogenetic relationships of non-typable Haemophilus influenzae (NTHi) strains prospectively isolated from healthy children and children with acute otitis media (AOM) were analysed using multilocus sequence typing (MLST). A total of 165 NTHi isolates were collected over a 3.5 year time frame during 2006 through 2009. The strains were tested for β-lactamase production; 28.5% were positive. Seventy different NTHi sequence types (STs) were identified of which 29 (41.4%) were novel. NTHi strains did not show any phylogenetic grouping or clustering among asymptomatic colonizing strains or strains that caused AOM, or based on β-lactamase enzyme production. Evaluation of triplets and other siblings over time demonstrated relatively frequent genetic exchanges in NTHi isolates in vivo in a short time frame and subsequent transfer among children in a family. Comparison of the MLST STs isolated at different time points showed that in 85% of the nasopharynx (NP) colonizations, NTHi strains cleared from the host within 3 months, that sequential colonization in the same child involved different strains in all cases except one, and that NP and middle ear isolates were identical STs in 84% of cases. In this first study of its type to our knowledge, we could not identify predominant MLST types among strains colonizing the NP versus those causing AOM or expressing a β-lactamase enzyme conferring penicillin resistance in children.

Anti-Bacterial Agents, Bacterial Typing Techniques, Child, Preschool, Drug Resistance, Bacterial, Ear, Middle, Female, Haemophilus Infections, Haemophilus influenzae, Humans, Infant, Male, Microbial Sensitivity Tests, Multilocus Sequence Typing, Nasopharynx, Otitis Media with Effusion, Phylogeny, beta-Lactamases
Anti-Bacterial Agents, Bacterial Typing Techniques, Child, Preschool, Drug Resistance, Bacterial, Ear, Middle, Female, Haemophilus Infections, Haemophilus influenzae, Humans, Infant, Male, Microbial Sensitivity Tests, Multilocus Sequence Typing, Nasopharynx, Otitis Media with Effusion, Phylogeny, beta-Lactamases
 
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