作者: Kevin M. Mason , Robert S. Munson , Lauren O. Bakaletz
DOI: 10.1128/IAI.73.1.599-608.2005
关键词: Beta defensin 、 Haemophilus influenzae 、 Otitis 、 Virology 、 Mutant 、 Biology 、 Pasteurellaceae 、 Microbiology 、 Operon 、 Plasmid 、 Antimicrobial peptides
摘要: Bacteria have evolved strategies to resist killing by antimicrobial peptides (APs), important effectors of innate immunity. The sap (sensitivity peptides) operon confers resistance AP-mediated Salmonella. We recently shown that sapA gene expression is upregulated in the middle ear a chinchilla model nontypeable Haemophilus influenzae (NTHI)-induced otitis media. Based on these findings, we constructed an NTHI strain containing Lux reporter plasmid driven promoter and demonstrated early yet transient within sites upper airway upon infection. hypothesized products mediate APs. In order test this hypothesis, nonpolar mutation 86-028NP, low-passage-number clinical isolate. mutant was approximately eightfold more sensitive than parent recombinant β-defensin 1. then assessed ability both colonize cause media chinchillas. significantly attenuated compared its survive nasopharynx chinchilla. addition, impaired compete with dual-strain challenge Our results indicate are for resisting activity APs may regulate, part, balance between normal carriage disease caused NTHI.