Удосконалення комерційної діяльності як фактор підвищення конкурентоспроможності підприємства

Additional file 5. ELISA to assess the interaction between Campylobacter -specific nanobodies and purified MOMP. The saturation binding curve of the interaction between coated MOMP (1 µg/mL) and a His-tagged nanobody (1 × 10−6 to 1 × 102 µg/mL) was obtained via ELISA. The dose-dependent inhibitory effect of a strep-tagged nanobody (1 × 10−6 to 1 × 102 µg/mL) on the interaction between His-tagged Nb84 (5.10−2 µg/mL) and MOMP (1 µg/mL), is demonstrated in the competition binding curve. Inhibition by strep-tagged (A) Nb5, (B) Nb22, (C) Nb23, (D) Nb24, (E) Nb49, (F) 84, (G) Nb15, (H) Nb32, (I) Nb34, (J) Nb45, (K) Nb48 and (L) Nb63, was assessed. The ELISA was developed with mouse anti-Histidine tag monoclonal antibody and goat anti-mouse IgG conjugated to alkaline phosphatase. The error bars represent the standard deviations

Comparison of Biofilm Formation between Major Clonal Lineages of Methicillin Resistant <i>Staphylococcus aureus</i>

<div><p>Objectives</p><p>Epidemic methicillin-resistant <i>S. aureus</i> (MRSA) clones cause infections in both hospital and community settings. As a biofilm phenotype further facilitates evasion of the host immune system and antibiotics, we compared the biofilm-forming capacities of various MRSA clones.</p><p>Methods</p><p>Seventy-six MRSA classified into 13 clones (USA300, EMRSA-15, Hungarian/Brazilian etc.), and isolated from infections or from carriers were studied for biofilm formation under static and dynamic conditions. Static biofilms in microtitre plates were quantified colorimetrically. Dynamic biofilms (Bioflux 200, Fluxion, USA) were studied by confocal laser-scanning and time-lapse microscopy, and the total volume occupied by live/dead bacteria quantified by Volocity 5.4.1 (Improvision, UK).</p><p>Results</p><p>MRSA harbouring SCC<i>mec</i> IV produced significantly more biomass under static conditions than SCC<i>mec</i> I–III (P = 0.003), and those harbouring SCC<i>mec</i> II significantly less than those harbouring SCC<i>mec</i> I or III (P<0.001). In the dynamic model, SCC<i>mec</i> I–III harbouring MRSA were significantly better biofilm formers than SCC<i>mec</i> IV (P = 0.036). Only 16 strains successfully formed biofilms under both conditions, of which 13 harboured SCC<i>mec</i> IV and included all tested USA300 strains (n = 3). However, USA300 demonstrated remarkably lower percentages of cell-occupied space (6.6%) compared to the other clones (EMRSA-15 = 19.0%) under dynamic conditions. Time-lapse microscopy of dynamic biofilms demonstrated that USA300 formed long viscoelastic tethers that stretched far from the point of attachment, while EMRSA-15 consisted of micro-colonies attached densely to the surface.</p><p>Conclusions</p><p>MRSA harbouring SCC<i>mec</i> types IV and I–III demonstrate distinct biofilm forming capacities, possibly owing to their adaptation to the community and hospital settings, respectively. USA300 demonstrated abundant biofilm formation under both conditions, which probably confers a competitive advantage, contributing to its remarkable success as a pathogen.</p></div

Live/dead BacLight staining and CLSM on 72-hour old MRSA biofilms under shear flow (Bioflux system).

<p>A) 3-dimensional representations. B) 2-dimensional projections, thin white lines in the xy plane depict the location of the section plane on the z axis. White bars have a length of 10 µm.</p

Space occupied by live (green) or dead (red) or total (grey) cells by different epidemic MRSA clones in a biofilm.

<p>Error bars denote standard deviations were calculated using 1 (USA300, EMRSA-15), 2 (USA600, Hungarian/Brazilian, Iberian) or 3 (USA500) independent z-stacks.</p

Performance of MRSA clones in the static and shear flow assay.

<p>A) In the static assay: biomass production was subdivided into weak, moderate and strong. B) In the shear flow assay biofilm formation was assessed as positive or negative.</p

Box-whisker plot of biofilm formation by MRSA clones in the static assay.

<p>Boxes depict the 95% CI, black horizontal lines the average OD492 value, and the whiskers the OD492 value range (lowest and highest values) for each clone.</p

Overview of MRSA clone characteristics, site of isolation, and biofilm formation in static and shear flow assays.

<p>Overview of MRSA clone characteristics, site of isolation, and biofilm formation in static and shear flow assays.</p