Brackish Water Benthic Shellfish ( Corbicula japonica ) as a Biological Indicator for Cryptosporidium parvum Oocysts in River Water

2004 ◽  
Vol 72 (1) ◽  
pp. 29-37 ◽  
Author(s):  
T. Ohyama ◽  
T. Izumi ◽  
K. Yagita ◽  
T. Endo ◽  
Y. Itoh
Keyword(s):  
River Water ◽  
Cryptosporidium Parvum ◽  
Brackish Water ◽  
Biological Indicator ◽  
Corbicula Japonica ◽  
Cryptosporidium Parvum Oocysts

scholarly journals Viability and Infectivity of Cryptosporidium parvum Oocysts Detected in River Water in Hokkaido, Japan

2003 ◽  
Vol 65 (5) ◽  
pp. 585-589 ◽  
Author(s):  
Yoshinori TSUSHIMA ◽  
Panagiotis KARANIS ◽  
Takenori KAMADA ◽  
Xuenan XUAN ◽  
Levi H. C. MAKALA ◽  
...  
Keyword(s):  
River Water ◽  
Cryptosporidium Parvum ◽  
Cryptosporidium Parvum Oocysts

Depressed filtration ripening enhances removal of Cryptosporidium parvum

2002 ◽  
Vol 2 (3) ◽  
pp. 159-168 ◽  
Author(s):  
V. Gitis ◽  
R.C. Haught ◽  
R.M. Clark ◽  
E. Radha Krishnan
Keyword(s):  
Surface Water ◽  
Cryptosporidium Parvum ◽  
Pilot Scale ◽  
Kaolin Clay ◽  
Clay Particles ◽  
Physico Chemical ◽  
Cryptosporidium Parvum Oocysts ◽  
Granular Filtration ◽  
Electrostatic Adhesion ◽  
Innovative Concept

Pilot-scale experiments were conducted to investigate removal of Cryptosporidium parvum by contact granular filtration. The research demonstrated enhanced removal of Cryptosporidium parvum in the presence of kaolin particles. This is believed to be due electrostatic adhesion of Cryptosporidium parvum oocysts to the kaolin clay particles. The elementary physico-chemical interactions between filter granules and suspension particles will be discussed. This innovative concept was successfully implemented to reduce the ripening sequence of subsequent filtration experimental test runs by the addition of large surface area particles to slurry of kaolin and Cryptosporidium parvum in surface water.

Survival of giardia, cryptosporidium, poliovirus and salmonella in marine waters

1997 ◽  
Vol 35 (11-12) ◽  
pp. 261-268 ◽  
Author(s):  
D. C. Johnson ◽  
C. E. Enriquez ◽  
I. L. Pepper ◽  
T. L. Davis ◽  
C. P. Gerba ◽  
...  
Keyword(s):  
Water Quality ◽  
Salmonella Typhimurium ◽  
Cryptosporidium Parvum ◽  
Common Method ◽  
Waterborne Pathogens ◽  
Protozoan Parasites ◽  
Marine Waters ◽  
Untreated Sewage ◽  
Cryptosporidium Parvum Oocysts ◽  
Giardia Muris

Discharge of sewage into the ocean is still a common method of disposal worldwide. Both treated and untreated sewage may contain significant concentrations of waterborne pathogens, such as Giardia, Cryptosporidium, poliovirus and Salmonella. Limited studies exist on the survival of poliovirus and Salmonella in marine waters; however, almost no information exists on the survival of protozoan parasites in marine waters. This study examined the survival of Giardia muris cysts, Cryptosporidium parvum oocysts, poliovirus-1 and Salmonella typhimurium in marine waters. The survival of the microorganisms varied according to the presence of light, salinity and water quality (as determined by quantity of enterococci). All microorganisms survived longer in the dark than in sunlight, the order of survival in sunlight being: Cryptosporidium > poliovirus > Giardia > Salmonella.

Survival of cryptosporidium parvum, escherichia coli, faecal enterococci and clostridium perfringens in river water: influence of temperature and autochthonous microorganisms

1997 ◽  
Vol 35 (11-12) ◽  
pp. 249-252 ◽  
Author(s):  
G. J. Medema ◽  
M. Bahar ◽  
F. M. Schets
Keyword(s):  
Surface Water ◽  
River Water ◽  
Cryptosporidium Parvum ◽  
Health Hazard ◽  
Influence Of Temperature ◽  
E Coli ◽  
Untreated Water ◽  
Time Required ◽  
Micro Organisms

Oocysts of Cryptosporidium parvum can survive for several months in surface water, one of the main factors determining their success in environmental transmission and thus their health hazard via water. Several factors in the environment, e.g. temperature, presence of predators and exo-enzymes will probably influence oocyst survival. The high persistence of oocysts may also limit the value of traditional faecal indicator bacteria. The aim of this study was to determine the rate at which C parvum oocysts, E coli, faecal enterococci and C perfringens spores die in surface water and the influence of temperature and the presence of autochthonous (micro)organisms on the die-off rate. Microcosms with autoclaved river water were inoculated with the organisms. Microcosms with untreated river water were inoculated with concentrated primary effluent containing the bacteria and with C parvum oocysts. Microcosms were incubated at 5°C or 15°C at 100rpm. Viability of oocysts was monitored by in vitro excystation and dye-exclusion; viability of the bacteria was determined on appropriate selective media. When pseudo first-order die-off kinetics were assumed, the die-off rate of oocysts at 5°C was 0.010 log10/d and at 15°C, 0.006–0.024 log10/d. These rates underestimate die-off since oocyst disintegration was not accounted for. Incubation in autoclaved or untreated water did influence the die-off rate of oocysts at 15°C but not at 5°C. The die-off rate of E coli and enterococci was faster in the non-sterile river water than in autoclaved water at both temperatures. At 15°C, E coli (and possibly E faecium) even multiplied in autoclaved water. In untreated river water, the die-off of E coli and enterococci was approximately 10x faster than die-off of oocysts but die-off rates of C perfringens were lower than those of oocysts. As for oocysts, die-off of the bacteria and spores was faster at 15°C than at 5°C. Oocysts are very persistent in river water: the time required for a 10x reduction in viability being 40–160d at 15°C and 100d at 5°C. Biological/biochemical activity influenced oocyst survival at 15°C and survival of both vegetative bacteria at 5 and 15°C. The rapid die-off of E coli and enterococci makes them less suitable as indicators of oocyst presence in water. As C perfringens survived longer in untreated river water than oocysts, it may prove useful as an indicator of the presence of C parvum.

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