This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Butkus, M. A. Articles by Labare, M. P. Search for Related Content PubMed PubMed Citation Articles by Butkus, M. A. Articles by Labare, M. P. Agricola Articles by Butkus, M. A. Articles by Labare, M. P.

 Previous Article  |  Next Article 

Applied and Environmental Microbiology, July 2003, p. 3819-3825, Vol. 69, No. 7
0099-2240/03/$08.00+0     DOI: 10.1128/AEM.69.7.3819-3825.2003

Influence of Surface Characteristics on the Stability of Cryptosporidium parvum Oocysts

Michael A. Butkus,^1* J. Timothy Bays,² and Michael P. Labare²

Environmental Engineering Program, Department of Geography and Environmental Engineering,¹ Department of Chemistry and Life Sciences, United States Military Academy, West Point, New York 10996²

Received 13 February 2003/ Accepted 25 March 2003

Microelectrophoresis is a common technique for probing the surface chemistry of the Cryptosporidium parvum oocyst. Results of previous studies of the electrophoretic mobility of C. parvum oocysts in which microelectrophoresis was used are incongruent. In this work we demonstrated that capillary electrophoresis may also be used to probe the surface characteristics of C. parvum oocysts, and we related the surface chemistry of C. parvum oocysts to their stability in water. Capillary electrophoresis results indicated that oocysts which were washed in a phosphate buffer solution had neutrally charged surfaces. Inactivation of oocysts with formalin did not influence their electrophoretic mobility, while oocyst populations that were washed in distilled water consisted of cells with both neutral and negative surface charges. These results indicate that washing oocysts in low-ionic-strength distilled water can impart a negative charge to a fraction of the oocysts in the sample. Rapid coagulation experiments indicated that oocysts did not aggregate in a 0.5 M NaCl solution; oocyst stability in the salt solution may have been the result of Lewis acid-base forces, steric stabilization, or some other factor. The presence of sucrose and Percoll could not be readily identified on the surface of C. parvum oocysts by attenuated total reflectance-Fourier transform infrared spectroscopy, suggesting that these purification reagents may not be responsible for the stability of the uncharged oocysts. These findings imply that precipitate enmeshment may be the optimal mechanism of coagulation for removal of oocysts in water treatment systems. The results of this work may help elucidate the causes of variation in oocyst surface characteristics, may ultimately lead to improved removal efficiencies in full-scale water treatment systems, and may improve fate and transport predictions for oocysts in natural systems.

---

* Corresponding author. Mailing address: Environmental Engineering Program, Department of Geography and Environmental Engineering, United States Military Academy, West Point, NY 10996. Phone: (845) 938-2820. Fax: (845) 938-3339. E-mail: bm8375{at}exmail.usma.edu.

---

Applied and Environmental Microbiology, July 2003, p. 3819-3825, Vol. 69, No. 7
0099-2240/03/$08.00+0     DOI: 10.1128/AEM.69.7.3819-3825.2003
Copyright © 2003, American Society for Microbiology. All Rights Reserved.

This article has been cited by other articles:

• Searcy, K. E., Packman, A. I., Atwill, E. R., Harter, T. (2005). Association of Cryptosporidium parvum with Suspended Particles: Impact on Oocyst Sedimentation. Appl. Environ. Microbiol. 71: 1072-1078 [Abstract] [Full Text]