In-situ monitoring of Cryptosporidium parvum oocyst surface adhesion using ATR-FTIR spectroscopy

Xiaodong Gao, Jon Chorover

Research output: Contribution to journalArticle

23 Citations (Scopus)

Abstract

Surface chemistry and molecular interaction mechanisms of Cryptosporidium parvum oocysts with a ZnSe internal reflection element (IRE) surface were investigated as a function of pH and ionic strength in NaCl and CaCl2 background electrolyte using in-situ ATR-FTIR spectroscopy. Since the surface properties of oocysts play an important role in adhesion behavior, the effects of surface modifications that are commonly employed to inactivate the pathogen for laboratory studies, including viable (control), formalin-, and heat-inactivation, were also examined. The ATR-FTIR spectra of oocyst surfaces exhibit amide, carboxylate, phosphate, and polysaccharide functional groups. Results indicate that changes in solution chemistry strongly impact oocyst adhesion behavior in aqueous systems. Increasing ionic strength from 1 to 100 mM or decreasing pH from 9.0 to 3.0 resulted in an increase in oocyst adhesion to the IRE surface as measured by IR absorbance. For equivalent ionic strength, the adhesion rate was found to be independent of CaCl2 versus NaCl electrolyte solution, but was increased following formalin and heat treatments. This latter effect correlated with molecular changes reflected in spectral data. The ratio of amide I:amide II band intensities increased, and sugar ring vibrations at 1023 cm-1 became sharper and more intense following formalin treatment. Similar changes in the polysaccharide region were observed following heat treatment, and protein secondary structure was also altered from mainly parallel β-sheet to anti-parallel β-sheet conformation.

Original languageEnglish (US)
Pages (from-to)169-176
Number of pages8
JournalColloids and Surfaces B: Biointerfaces
Volume71
Issue number2
DOIs
StatePublished - Jul 1 2009

Fingerprint

Cryptosporidium parvum
Oocysts
Fourier Transform Infrared Spectroscopy
Spectrum Analysis
adhesion
Adhesion
Ionic strength
Amides
Formaldehyde
Spectroscopy
Monitoring
Osmolar Concentration
amides
Polysaccharides
spectroscopy
Hot Temperature
Electrolytes
polysaccharides
Heat treatment
heat treatment

Keywords

  • Adhesion
  • ATR-FTIR
  • Oocysts
  • Solution chemistry
  • Surface modification

ASJC Scopus subject areas

  • Biotechnology
  • Colloid and Surface Chemistry
  • Physical and Theoretical Chemistry
  • Surfaces and Interfaces

Cite this

In-situ monitoring of Cryptosporidium parvum oocyst surface adhesion using ATR-FTIR spectroscopy. / Gao, Xiaodong; Chorover, Jon.

In: Colloids and Surfaces B: Biointerfaces, Vol. 71, No. 2, 01.07.2009, p. 169-176.

Research output: Contribution to journalArticle

@article{851f66b142184b70aefbecad9dd2dbc2,
title = "In-situ monitoring of Cryptosporidium parvum oocyst surface adhesion using ATR-FTIR spectroscopy",
abstract = "Surface chemistry and molecular interaction mechanisms of Cryptosporidium parvum oocysts with a ZnSe internal reflection element (IRE) surface were investigated as a function of pH and ionic strength in NaCl and CaCl2 background electrolyte using in-situ ATR-FTIR spectroscopy. Since the surface properties of oocysts play an important role in adhesion behavior, the effects of surface modifications that are commonly employed to inactivate the pathogen for laboratory studies, including viable (control), formalin-, and heat-inactivation, were also examined. The ATR-FTIR spectra of oocyst surfaces exhibit amide, carboxylate, phosphate, and polysaccharide functional groups. Results indicate that changes in solution chemistry strongly impact oocyst adhesion behavior in aqueous systems. Increasing ionic strength from 1 to 100 mM or decreasing pH from 9.0 to 3.0 resulted in an increase in oocyst adhesion to the IRE surface as measured by IR absorbance. For equivalent ionic strength, the adhesion rate was found to be independent of CaCl2 versus NaCl electrolyte solution, but was increased following formalin and heat treatments. This latter effect correlated with molecular changes reflected in spectral data. The ratio of amide I:amide II band intensities increased, and sugar ring vibrations at 1023 cm-1 became sharper and more intense following formalin treatment. Similar changes in the polysaccharide region were observed following heat treatment, and protein secondary structure was also altered from mainly parallel β-sheet to anti-parallel β-sheet conformation.",
keywords = "Adhesion, ATR-FTIR, Oocysts, Solution chemistry, Surface modification",
author = "Xiaodong Gao and Jon Chorover",
year = "2009",
month = "7",
day = "1",
doi = "10.1016/j.colsurfb.2009.02.003",
language = "English (US)",
volume = "71",
pages = "169--176",
journal = "Colloids and Surfaces B: Biointerfaces",
issn = "0927-7765",
publisher = "Elsevier",
number = "2",

}

TY - JOUR

T1 - In-situ monitoring of Cryptosporidium parvum oocyst surface adhesion using ATR-FTIR spectroscopy

AU - Gao, Xiaodong

AU - Chorover, Jon

PY - 2009/7/1

Y1 - 2009/7/1

N2 - Surface chemistry and molecular interaction mechanisms of Cryptosporidium parvum oocysts with a ZnSe internal reflection element (IRE) surface were investigated as a function of pH and ionic strength in NaCl and CaCl2 background electrolyte using in-situ ATR-FTIR spectroscopy. Since the surface properties of oocysts play an important role in adhesion behavior, the effects of surface modifications that are commonly employed to inactivate the pathogen for laboratory studies, including viable (control), formalin-, and heat-inactivation, were also examined. The ATR-FTIR spectra of oocyst surfaces exhibit amide, carboxylate, phosphate, and polysaccharide functional groups. Results indicate that changes in solution chemistry strongly impact oocyst adhesion behavior in aqueous systems. Increasing ionic strength from 1 to 100 mM or decreasing pH from 9.0 to 3.0 resulted in an increase in oocyst adhesion to the IRE surface as measured by IR absorbance. For equivalent ionic strength, the adhesion rate was found to be independent of CaCl2 versus NaCl electrolyte solution, but was increased following formalin and heat treatments. This latter effect correlated with molecular changes reflected in spectral data. The ratio of amide I:amide II band intensities increased, and sugar ring vibrations at 1023 cm-1 became sharper and more intense following formalin treatment. Similar changes in the polysaccharide region were observed following heat treatment, and protein secondary structure was also altered from mainly parallel β-sheet to anti-parallel β-sheet conformation.

AB - Surface chemistry and molecular interaction mechanisms of Cryptosporidium parvum oocysts with a ZnSe internal reflection element (IRE) surface were investigated as a function of pH and ionic strength in NaCl and CaCl2 background electrolyte using in-situ ATR-FTIR spectroscopy. Since the surface properties of oocysts play an important role in adhesion behavior, the effects of surface modifications that are commonly employed to inactivate the pathogen for laboratory studies, including viable (control), formalin-, and heat-inactivation, were also examined. The ATR-FTIR spectra of oocyst surfaces exhibit amide, carboxylate, phosphate, and polysaccharide functional groups. Results indicate that changes in solution chemistry strongly impact oocyst adhesion behavior in aqueous systems. Increasing ionic strength from 1 to 100 mM or decreasing pH from 9.0 to 3.0 resulted in an increase in oocyst adhesion to the IRE surface as measured by IR absorbance. For equivalent ionic strength, the adhesion rate was found to be independent of CaCl2 versus NaCl electrolyte solution, but was increased following formalin and heat treatments. This latter effect correlated with molecular changes reflected in spectral data. The ratio of amide I:amide II band intensities increased, and sugar ring vibrations at 1023 cm-1 became sharper and more intense following formalin treatment. Similar changes in the polysaccharide region were observed following heat treatment, and protein secondary structure was also altered from mainly parallel β-sheet to anti-parallel β-sheet conformation.

KW - Adhesion

KW - ATR-FTIR

KW - Oocysts

KW - Solution chemistry

KW - Surface modification

UR - http://www.scopus.com/inward/record.url?scp=67349129215&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=67349129215&partnerID=8YFLogxK

U2 - 10.1016/j.colsurfb.2009.02.003

DO - 10.1016/j.colsurfb.2009.02.003

M3 - Article

VL - 71

SP - 169

EP - 176

JO - Colloids and Surfaces B: Biointerfaces

JF - Colloids and Surfaces B: Biointerfaces

SN - 0927-7765

IS - 2

ER -