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Surface Plasmon Resonance (SPR) for the Evaluation of Shear-Force-Dependent Bacterial Adhesion.

Zagorodko O, Bouckaert J, Dumych T, Bilyy R, Larroulet I, Yanguas Serrano A, Alvarez Dorta D, Gouin SG, Dima SO, Oancea F, Boukherroub R, Szunerits S - Biosensors (Basel) (2015)

Bottom Line: In this work we investigate whether flow rate changes in microchannels integrated on surface plasmon resonance (SPR) surfaces would allow for investigating such processes in an easy and high-throughput manner.We demonstrate that adhesion of uropathogenic E. coli UTI89 on heptyl α-d-mannopyranoside-modified gold SPR substrates is minimal under almost static conditions (flow rates of 10 µL·min⁻¹), and reaches a maximum at flow rates of 30 µL·min⁻¹ (≈30 mPa).This concept is applicable to the investigation of any ligand-pathogen interactions, offering a robust, easy, and fast method for screening adhesion characteristics of pathogens to ligand-modified interfaces.

View Article: PubMed Central - PubMed

Affiliation: Institute of Electronics, Microelectronics and Nanotechnology (IEMN), UMR-CNRS 8520, Université Lille 1, Cité Scientifique, 59655 Villeneuve d'Ascq, France. morjakzzz@gmail.com.

ABSTRACT
The colonization of Escherichia coli (E. coli) to host cell surfaces is known to be a glycan-specific process that can be modulated by shear stress. In this work we investigate whether flow rate changes in microchannels integrated on surface plasmon resonance (SPR) surfaces would allow for investigating such processes in an easy and high-throughput manner. We demonstrate that adhesion of uropathogenic E. coli UTI89 on heptyl α-d-mannopyranoside-modified gold SPR substrates is minimal under almost static conditions (flow rates of 10 µL·min⁻¹), and reaches a maximum at flow rates of 30 µL·min⁻¹ (≈30 mPa). This concept is applicable to the investigation of any ligand-pathogen interactions, offering a robust, easy, and fast method for screening adhesion characteristics of pathogens to ligand-modified interfaces.

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Binding affinity of E. coli UTI89 (108 cfu/mL) to Au and Au-HM as a function of flow rate. (a) Bar graph of change in SPR signal upon addition of E. coli UTI (108 cfu/mL); (b) SPR sensogram for three different flow rates; (c) binding affinity of E. coli UTI89 Q133K (108 cfu/mL) and UTI89 ∆fimH (108 cfu/ml) to Au-HM surfaces as a function of flow rate.
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biosensors-05-00276-f003: Binding affinity of E. coli UTI89 (108 cfu/mL) to Au and Au-HM as a function of flow rate. (a) Bar graph of change in SPR signal upon addition of E. coli UTI (108 cfu/mL); (b) SPR sensogram for three different flow rates; (c) binding affinity of E. coli UTI89 Q133K (108 cfu/mL) and UTI89 ∆fimH (108 cfu/ml) to Au-HM surfaces as a function of flow rate.

Mentions: We therefore investigated the influence of flow rate on the binding strength of E. coli UTI89 onto Au and Au-HM. The microfluidic channel used in combination with the SPR setup allowed us to vary the flow rate between 5 and 100 µL·min−1, which corresponds to a shear of ≈5–100 mPa (0.005–0.1 pN/μm2), a range used by others [22,40]. Figure 3a shows the binding of E. coli UTI89 at different flow rates to Au and Au-HM. In the case of unmodified gold SPR interfaces, the flow rate has no effect on the change in the SPR signal and thus the adhesion strength of E. coli UTI89. In fact, almost no adhesion is observed for gold only. This was in contrast to the Au-HM interface, where E. coli adhesion increased strongly with increasing flow rate from 5–30 µL·min−1, where a maximum in SPR response was reached. Higher flow rates resulted in a gradual decrease in the SPR signal. At 90 µL·min−1, about half of the maximal value was reached, and completely dropped to very low values at 100 µL·min−1. Interestingly, the increase in adhesion until a flow of 30 µL·min−1 is more rapid than the decrease in adhesion above the maximum value. The results presented in Figure 3a clearly indicate the mannose-specific mechanism of the flow-rate-dependent E. coli adhesion to Au-HM. From Figure 3b, the time to reach a maximal adhesion is ≈5–8 min and depends on the flow rate. While the protein FimH is highly conserved in E. coli UTI89, mutations in the binding pocket could, however, influence adhesion under shear flow. We were thus intrigued to investigate the binding characteristics of strain UTI89 Q133K and of UTI89 ∆fimH. In the case of bacterial strain UTI89 ∆fimH, the capacity to bind to bladder cells is lost due to the incapacity to form normal type-1 pili in the absence of the FimH protein [41]. As seen in Figure 3c, no shear-force enhanced adhesion could be observed for this strain: while there is a small increase in the SPR signal at a flow rate of 30 µL·min−1 in the case of UTI89 Q133K, the SPR signal upon the addition of UTI89 ∆fimH is completely constant for the different flow rates measured. This is line with reports that fimbrial proteins and in particular the FimH adhesin play a key role in the adherence of uropathogenic E. coli to urothelial surfaces. A loss of fimbriae results in the impossibility of adhering to mannose-carrying surfaces and ultimately to the formation of biofilms.


Surface Plasmon Resonance (SPR) for the Evaluation of Shear-Force-Dependent Bacterial Adhesion.

Zagorodko O, Bouckaert J, Dumych T, Bilyy R, Larroulet I, Yanguas Serrano A, Alvarez Dorta D, Gouin SG, Dima SO, Oancea F, Boukherroub R, Szunerits S - Biosensors (Basel) (2015)

Binding affinity of E. coli UTI89 (108 cfu/mL) to Au and Au-HM as a function of flow rate. (a) Bar graph of change in SPR signal upon addition of E. coli UTI (108 cfu/mL); (b) SPR sensogram for three different flow rates; (c) binding affinity of E. coli UTI89 Q133K (108 cfu/mL) and UTI89 ∆fimH (108 cfu/ml) to Au-HM surfaces as a function of flow rate.
© Copyright Policy
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4493549&req=5

biosensors-05-00276-f003: Binding affinity of E. coli UTI89 (108 cfu/mL) to Au and Au-HM as a function of flow rate. (a) Bar graph of change in SPR signal upon addition of E. coli UTI (108 cfu/mL); (b) SPR sensogram for three different flow rates; (c) binding affinity of E. coli UTI89 Q133K (108 cfu/mL) and UTI89 ∆fimH (108 cfu/ml) to Au-HM surfaces as a function of flow rate.
Mentions: We therefore investigated the influence of flow rate on the binding strength of E. coli UTI89 onto Au and Au-HM. The microfluidic channel used in combination with the SPR setup allowed us to vary the flow rate between 5 and 100 µL·min−1, which corresponds to a shear of ≈5–100 mPa (0.005–0.1 pN/μm2), a range used by others [22,40]. Figure 3a shows the binding of E. coli UTI89 at different flow rates to Au and Au-HM. In the case of unmodified gold SPR interfaces, the flow rate has no effect on the change in the SPR signal and thus the adhesion strength of E. coli UTI89. In fact, almost no adhesion is observed for gold only. This was in contrast to the Au-HM interface, where E. coli adhesion increased strongly with increasing flow rate from 5–30 µL·min−1, where a maximum in SPR response was reached. Higher flow rates resulted in a gradual decrease in the SPR signal. At 90 µL·min−1, about half of the maximal value was reached, and completely dropped to very low values at 100 µL·min−1. Interestingly, the increase in adhesion until a flow of 30 µL·min−1 is more rapid than the decrease in adhesion above the maximum value. The results presented in Figure 3a clearly indicate the mannose-specific mechanism of the flow-rate-dependent E. coli adhesion to Au-HM. From Figure 3b, the time to reach a maximal adhesion is ≈5–8 min and depends on the flow rate. While the protein FimH is highly conserved in E. coli UTI89, mutations in the binding pocket could, however, influence adhesion under shear flow. We were thus intrigued to investigate the binding characteristics of strain UTI89 Q133K and of UTI89 ∆fimH. In the case of bacterial strain UTI89 ∆fimH, the capacity to bind to bladder cells is lost due to the incapacity to form normal type-1 pili in the absence of the FimH protein [41]. As seen in Figure 3c, no shear-force enhanced adhesion could be observed for this strain: while there is a small increase in the SPR signal at a flow rate of 30 µL·min−1 in the case of UTI89 Q133K, the SPR signal upon the addition of UTI89 ∆fimH is completely constant for the different flow rates measured. This is line with reports that fimbrial proteins and in particular the FimH adhesin play a key role in the adherence of uropathogenic E. coli to urothelial surfaces. A loss of fimbriae results in the impossibility of adhering to mannose-carrying surfaces and ultimately to the formation of biofilms.

Bottom Line: In this work we investigate whether flow rate changes in microchannels integrated on surface plasmon resonance (SPR) surfaces would allow for investigating such processes in an easy and high-throughput manner.We demonstrate that adhesion of uropathogenic E. coli UTI89 on heptyl α-d-mannopyranoside-modified gold SPR substrates is minimal under almost static conditions (flow rates of 10 µL·min⁻¹), and reaches a maximum at flow rates of 30 µL·min⁻¹ (≈30 mPa).This concept is applicable to the investigation of any ligand-pathogen interactions, offering a robust, easy, and fast method for screening adhesion characteristics of pathogens to ligand-modified interfaces.

View Article: PubMed Central - PubMed

Affiliation: Institute of Electronics, Microelectronics and Nanotechnology (IEMN), UMR-CNRS 8520, Université Lille 1, Cité Scientifique, 59655 Villeneuve d'Ascq, France. morjakzzz@gmail.com.

ABSTRACT
The colonization of Escherichia coli (E. coli) to host cell surfaces is known to be a glycan-specific process that can be modulated by shear stress. In this work we investigate whether flow rate changes in microchannels integrated on surface plasmon resonance (SPR) surfaces would allow for investigating such processes in an easy and high-throughput manner. We demonstrate that adhesion of uropathogenic E. coli UTI89 on heptyl α-d-mannopyranoside-modified gold SPR substrates is minimal under almost static conditions (flow rates of 10 µL·min⁻¹), and reaches a maximum at flow rates of 30 µL·min⁻¹ (≈30 mPa). This concept is applicable to the investigation of any ligand-pathogen interactions, offering a robust, easy, and fast method for screening adhesion characteristics of pathogens to ligand-modified interfaces.

Show MeSH
Related in: MedlinePlus