

@article {9119,
	title = {{Effect of various environmental factors on the viability of Cryptosporidium parvum oocysts}},
	journal = {Journal of Applied Microbiology},
	volume = {104},
	number = {4},
	year = {2008},
	pages = {980{\textendash}986},
	abstract = {Aims: To evaluate individual and combined effects of temperature (4, 18 and 25{\textdegree}C), pH (7 and 10), ammonia (5 and 50 mg~l-1) and exposure time (1, 2, 4 and 6 days) on the viability of Cryptosporidium parvum oocysts in water. Methods and Results: The viability of oocysts was evaluated using the fluorogenic vital dyes assay (4',6-diamidino-2-phenylindole and propidium iodide). All the factors analysed (temperature, pH, ammonia and exposure time) and their interaction were statistically significant (P~{\{}{\textless}{\}}~0{\{}{\textperiodcentered}{\}}005). Exposure of oocysts to pH 10 for 6 days at 25{\textdegree}C reduced oocyst viability from \~{}80{\{}{\%}{\}} to 51{\{}{\%}{\}}. Similarly, the exposure of C. parvum oocysts to 5~mg NH3~l-1 and 50~mg NH3~l-1 for 4 days reduced their viability from between \~{}80{\{}{\%}{\}} to 41{\{}{\textperiodcentered}{\}}5{\{}{\%}{\}} and 14{\{}{\textperiodcentered}{\}}8{\{}{\%}{\}}, respectively. Conclusions: The interaction between pH, temperature and exposure time may have adverse effects on the survival of C. parvum oocysts in water. Low concentrations of ammonia, as commonly found in alga-based wastewater systems, over a long period of time can produce high C. parvum oocyst inactivation rates. Significance and Impact of the Study: This study provides relevant data on the inactivation of C. parvum oocysts in alga-based wastewater-treatment systems in the northwest of Spain.},
	keywords = {Ammonia, Cryptosporidium parvum, pH, Temperature, viability, water},
	isbn = {1365-2672},
	issn = {13645072},
	doi = {10.1111/j.1365-2672.2007.03620.x},
	author = {Reinoso, R and Becares, E and Smith, H V}
}
