Medizinische Universität Graz Austria/Österreich - Forschungsportal - Medical University of Graz
Gewählte Publikation:
SHR Neuro Krebs Kardio Lipid Stoffw Microb
Lichtenegger, S; Bina, I; Durakovic, S; Glaser, P; Tutz, S; Schild, S; Reidl, J.
Serum resistance and phase variation of a nasopharyngeal non-typeable Haemophilus influenzae isolate.
Int J Med Microbiol. 2017; 307(2):139-146
Doi: 10.1016/j.ijmm.2017.01.005
Web of Science
PubMed
FullText
FullText_MUG
- Führende Autor*innen der Med Uni Graz
- Strießnig-Bina Isabelle
- Wagner-Lichtenegger Sabine
- Altmetrics:
- Dimensions Citations:
- Plum Analytics:
- Scite (citation analytics):
- Abstract:
- Haemophilus influenzae harbours a complex array of factors to resist human complement attack. As non-typeable H. influenzae (NTHi) strains do not possess a capsule, their serum resistance mainly depends on other mechanisms including LOS decoration. In this report, we describe the identification of a highly serum resistant, nasopharyngeal isolate (NTHi23) by screening a collection of 77 clinical isolates. For NTHi23, we defined the MLST sequence type 1133, which matches the profile of a previously published invasive NTHi isolate. A detailed genetic analysis revealed that NTHi23 shares several complement evading mechanisms with invasive disease isolates. These mechanisms include the functional expression of a retrograde phospholipid trafficking system and the presumable decoration of the LOS structure with sialic acid. By screening the NTHi23 population for spontaneous decreased serum resistance, we identified a clone, which was about 103-fold more sensitive to complement-mediated killing. Genome-wide analysis of this isolate revealed a phase variation in the N'-terminal region of lpsA, leading to a truncated version of the glycosyltransferase (LpsA). We further showed that a NTHi23 lpsA mutant exhibits a decreased invasion rate into human alveolar basal epithelial cells. Since only a small proportion of the NTHi23 population expressed the serum sensitive phenotype, resulting from lpsA phase-off, we conclude that the nasopharyngeal environment selected for a population expressing the intact and functional glycosyltransferase. Copyright © 2017 Elsevier GmbH. All rights reserved.
- Find related publications in this database (using NLM MeSH Indexing)
- Adult -
- Alveolar Epithelial Cells - microbiology
- Antigenic Variation -
- Blood Bactericidal Activity -
- Cell Line -
- Child -
- Endocytosis -
- Genotype -
- Glycosyltransferases - genetics
- Glycosyltransferases - metabolism
- Haemophilus influenzae - genetics
- Haemophilus influenzae - immunology
- Haemophilus influenzae - isolation & purification
- Haemophilus influenzae - physiology
- Humans -
- Immune Evasion -
- Multilocus Sequence Typing -
- Nasopharynx - microbiology
- Find related publications in this database (Keywords)
- Serum resistance
- lpsA
- Haemophilus influenzae
- Phase variation