Oocysts Cryptosporidium

Isolation and Identification of Giardia Cysts, Cryptosporidium Oocysts and Eree Living Pathogenic Amoebae in Water etc., 1989... 

Cryptosporidium is an intracellular protozoan parasite that is capable of completing its entire life cycle within one host. Humans become infected on ingestion of the oocysts, and autoinfection and persistent infections are possible owing to repeated life cycles within the GI tract.3 As few as 10 to 100 oocysts can cause infection.3... 

Simplest method of diagnosis is detection of oocysts by modified acid-fast staining of a stool specimen. Standard ova and parasite test does not include Cryptosporidium. 

Pure Ti02 was recently reported to be active in the disinfection of water contaminated by spores of the type Fusarium solani [142], Bacillus anthracis [143], or Cryptosporidium parvum oocysts [144], or when supported as nanocomposites on zeolite H(i for E. coli deactivation [145], and it found applications in water treatment as a replacement for chlorine. Ag-Ti02 immobilized systems were used for inactivation of bacteria, coupling the visible light response of the system and the strong bactericidal effect of Ag [146]. Silver was deposited on hydroxyapatite to form nanocomposites with a high capacity for bacterial adsorption and inactivation [147], or used for airborne bacterial remediation in indoor air [148],... 

Sheather sugar flotation is recommended for the concentration of Cryptosporidium cysts. Although these oocysts will concentrate when the Formalin-ethyl acetate or zinc sulfate technique is used, they are more readily detected with the Sheather sugar flotation, for they stand out sharply from the background in this solution of high specific gravity. This procedure may be performed on unfixed or Formalin-fixed feces. The procedure for Sheather sugar flotation is outlined below. 

The results are that Cryptosporidium oocysts stain bright red, and background materials stain blue or pale red. 

Kuczynska E., Boyer D.G., Shelton D.R., Comparison of immunofluorescence assay and immunomagnetic electrochemiluminescence in detection of Cryptosporidium parvum oocysts in karst water samples, J. Microbiol. Meth. 2003 53 17-26. 

Giardia cysts persist for a shorter period in irrigation water compared to Cryptosporidium oocysts (Karim et al, 2004 Skraber et al., 2007). Temperatures as low as —4 °C inactivate Giardia cysts in water while Cryptosporidium oocysts remained viable for >12 weeks at 4 °C (Karim et al.,... 

At 25 °C, Giardia cysts were inactivated in water within 2 weeks but Cryptosporidium oocysts survived for >10 weeks. Factors affecting the survival of pathogens in water have been reviewed by Bichai et al. (2008). 

Armon, R., Gold, D., Brodsky, M., and Oron, G. (2002). Surface and subsurface irrigation with effluents of different qualities and presence of Cryptosporidium oocysts in soil and on crops. Water Sci. Technol. 46,115-122. 

Robertson, L. J., Campbell, A. T., and Smith, H. V. (1992). Survival of Cryptosporidium parvum oocysts under various environmental pressures. Appl. Environ. Microbiol. 58, 3494-3500. 

In some instances the raw water reaching water treatment plants may contain pathogens such as the human infectious protozoon Cryptosporidium parvum. The environmental form of C parvum is a spheroidal oocyst of 4-6 microns diameter. The oocyst is resistant to conventional chemical disinfectants that are commonly used in water treatment such as chlorine or chloramines. It is therefore essential that Cryptosporidium be removed during the coagulation and filtration processes stage in the water... 

Entrala E, Mascaro C (1997) Glycolytic enzyme activities in Cryptosporidium parvum oocysts. FEMS Microbiol Lett 151 51-57... 

The detection of new kinds of microorganisms, such as the cysts and oocysts of parasites (Giardia, Cryptosporidium), the identification of more and more chemical pollutants in waters and increasing quality levels required for drinking and waste waters has induced new interest in ozonation and ozone-based advanced oxidation processes. However, care has to be taken in the application of ozonation, since recent research has indicated that presumably hazardous by-products can be formed, e. g. bromate in the ozonation of waters containing bromide. 

All surface waters contain particles of different origin, sizes and materials, which must be removed efficiently before water distribution. There is a renewed interest in improved particle separation due to the hygienic problems with infectious cysts and oocysts of parasites (Gia-rdia, Cryptosporidium), which are particles in the size range of 3-12 (am. Depending on the raw water quality, particle separation may be accomplished typically by ... 

J, low efficiency towards inactivation of parasites, such as Giardia muris and Cryptosporidium oocysts (Bersillon, 1999), as is the case with ozonation (Renn-ecker et al., 2000) ... 

Originally, the use of a smaller number of MP Hg lamps (P2 =1-5 kW) seemed to have several advantages over the LP Hg lamp systems, particularly with respect to inactivation of Cryptosporidium parvum oocysts at a low UV fluence Ho of 19 mj cm and a reduction factor i f of 3.9 (Bukhari et al, 1999). However, recent investigations consistently established a 3 log-unit inactivation of C. parvum oocysts at a germicidal UV fluence Hq of 25 mJ cm for both MP and LP Hg lamps. Both lamp types were found to be equally effective for the inactivation of oocysts when compared on a germicidal fluence basis (Craik et al, 2001). 

In conclusion, the resent research by Clancy et al. (2000, 1998), Bukhari et al. (1999) and Craik et al. (2001) has convincingly demonstrated that UV-C is highly effective at inactivating Cryptosporidium parvum oocysts (and Giardia muris cysts)... 

Clancy JL et al. (1998) Inactivation of Cryptosporidium Oocysts in Water using Ultraviolet Light, J. Am. Water Works Assoc. 90 92-102 cited in Clancy (1999). 

Clancy JL, Bukhari Z, HargyTM, Bolton JR, Dussert B, Marshall MM (2000) Comparison of Medium- and Low-Pressure Ultraviolet Light for Inactivation of Cryptosporidium parvum Oocysts, J. Am. Water Works Assoc. 92, No. 9 97-104. 

Craik SA, Weldon D, Finch GR, Bolton J R, Belosevic M (2001) Inactivation of Cryptosporidium Parvum Oocysts using Medium- and Low-Pressure Ultraviolet Radiation, Wat. Res. 35, No. 6 1387-1398. 

Cryptosporidiosis is contracted in practically the same way as giardiasis. That is, the parasite is passed in the feces of an infected person or the feces of animals. The waste may then contaminate water or food. Direct person-to-person transmission may also occur in day-care centers or other settings where handwashing practices are poor. It is estimated that as few as one to 10 oocysts constitute an infective dose. In 1993, waterborne Cryptosporidium sickened 403,000 Milwaukee residents and killed more than 100 people, many with HIV/AIDS. 

The diagnosis of cryptosporidiosis is posed by observation of the oocysts in the feces of infected individuals. Routine stool examination used for most parasites usually fails to detect Cryptosporidium, however. Thus, a stool specimen is examined using staining techniques available for this parasite. See Figure 2.12. 

The DE process is entirely a physical/mechaihcal operahon and can attain high log removals of Giardia cysts and Cryptosporidium oocysts without operator expertise in water chemistry relahng to coagulation (3,4,10,11,19-26). 

The results of the laboratory study performed by Ongerth and Hutton (22) confirmed that greater than 6 logs (99.9999%) of Cryptosporidium oocyst reduction can be achieved not only at the traditional 1 gallon per minute per square foot (gpm/ft ) operation, but also at a higher rate of 2 gpm/ft. ... 

The disinfection efficiency is dependent on the UV dosage as well as the physical and chemical conditions of the water and air to be disinfected. It is found that an UV irradiation dose of 8-14 mJ/cm is required to meet the 3-log inactivation of Cryptosporidium spp. oocysts (i.e., 99.9% killing) and 12-20 mJ/cm is necessary to achieve at least 3-log inactivation of Giardia spp. cysts in drinking water disinfection (13). The UV can also be used in seawater disinfection. A filter system combined with a series of 0.45-pm filters can reduce by as much as 60% of the bacteria in raw seawater. An UV dose 63.6 mJ/cm is enough to achieve 4-log Vibrio and Pseudomonas bacteria reduction (14). 

G-A. Shin, K. G. Linden, M. J. Arrowood, and M. D. Sobsey, Low-pressure UV inactivation and DNA repair potential of Cryptosporidium parvum oocysts. Applied Environmental Microbiology 67(7), 3029-3032 (2001). 

Fig. 6.8 Life cycle of Cryptosporidium. Sporulated oocysts, containing four sporozoites, are excreted by the infected host...

Oyster contamination coincided with rainfalls and increased stream flow Viable Cryptosporidium oocysts... 

Cryptosporidium species oocysts and microsporidian spores were infectious Cyclospora species oocysts were noninfectious... 

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