Outer membrane vesicles shield Moraxella catarrhalis β-lactamase from neutralization by serum IgG.

Forskningsoutput: TidskriftsbidragArtikel i vetenskaplig tidskrift

Abstract

OBJECTIVES: The aim of this study was to detect the presence of IgG against Moraxella catarrhalis β-lactamase in healthy adults, and to determine whether outer membrane vesicles (OMVs) could protect the enzyme from inhibition by anti-β-lactamase IgG. METHODS: Transmission electron microscopy was used to detect the presence of β-lactamase in OMVs. Sera were examined by ELISA for specific IgG directed against recombinant M. catarrhalis β-lactamase in addition to the outer membrane adhesins MID/Hag, UspA1 and A2. Binding of anti-β-lactamase IgG from serum to OMVs was analysed by flow cytometry. The chromogenic substrate nitrocefin was used to quantify β-lactamase enzyme activity. RESULTS: The presence of β-lactamase was determined in OMVs from a 9-year-old child suffering from M. catarrhalis sinusitis. Furthermore, anti-β-lactamase IgG was detected in sera obtained from healthy adults. Out of 40 adult blood donors (aged 18-65 years) tested, 6 (15.0%) carried anti-β-lactamase IgG. No correlation between IgG titres against β-lactamase and the adhesins was found. Flow cytometry analyses revealed that anti-β-lactamase IgG from serum bound to β-lactamase-positive OMVs. By comparing the β-lactamase activity of intact OMV with OMV that were permeabilized with saponin we found that OMVs shielded active β-lactamase from the anti-β-lactamase IgG. CONCLUSIONS: Moraxella catarrhalis β-lactamase is found in, or associated with, OMVs, providing clinical relevance for the vesicles in the spread of antibiotic resistance. Furthermore, OMVs protect β-lactamase from specific IgG.

Detaljer

Författare
Enheter & grupper
Forskningsområden

Ämnesklassifikation (UKÄ) – OBLIGATORISK

  • Farmakologi och toxikologi
Originalspråkengelska
Sidor (från-till)593-600
TidskriftJournal of Antimicrobial Chemotherapy
Volym68
Utgåva nummer3
StatusPublished - 2013
PublikationskategoriForskning
Peer review utfördJa

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Relaterad forskningsoutput

Magnus Paulsson, 2017, (Unpublished) Lund: Lund University: Faculty of Medicine. 84 s.

Forskningsoutput: AvhandlingDoktorsavhandling (sammanläggning)

Schaar, V., 2013, Medical Microbiology, Lund University.

Forskningsoutput: AvhandlingDoktorsavhandling (sammanläggning)

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