Method for enriching and purifying cryptosporidium and giardia in alga-containing water, and method for determining content of cryptosporidium and giardia

Abstract

The invention discloses a method for enriching and purifying cryptosporidium and giardia in alga-containing water, and a method for determining the content of cryptosporidium and giardia. The enrichment and purification method comprises the following steps: pressurizing alga-containing water, precipitating to remove algae, filtering the obtained supernatant by using a mixed acetate fiber filter membrane, dissolving enriched products in acetone, centrifuging to obtain an enriched precipitate containing cryptosporidium and giardia, adding a phosphate-tween buffer solution to the precipitate to prepare a cryptosporidium and giardia suspension, carrying out density gradient centrifuge treatment to obtain a cryptosporidium and giardia purified solution, filtering to make cryptosporidium and giardia adhered to the acetate fiber membrane, dyeing, carrying out fluorescence microscope detection, and counting. The enrichment and purification method is an improved method for concentrating, separating and purifying cryptosporidium and giardia in an alga-containing water sample, and reduces the interference of background impurities during microscope detection, and the detection method has the advantages of high recovery rate and accurate detection result, and accords with Quality Control Standard of Cryptosporidium and Giardia in Water prescribed by Environmental Protection Agency in USA.

Description

technical field [0001] The present invention relates to a method in the technical field of detection in water, in particular to a method for enriching and purifying Cryptosporidium oocysts and Giardia cysts in algae-containing water and a method for determining their content in algae-containing water . Background technique [0002] Cryptosporidium and Giardia (referred to as "two worms") are two pathogenic protozoa that parasitize in humans and animals. In recent years, there have been many water-borne diseases caused by "two worms" in water abroad. The outbreak of the virus has attracted widespread attention. As two important pathogenic microorganisms, "two worms" have been included in the "Drinking Water Hygienic Standard" (GB5749-2006), which clearly stipulates that the limit value should be <1 / 10L. [0003] Since the content of "two worms" in water is generally low, the existing detection of "two worms" usually needs to be completed through multiple detection steps ...

AI Technical Summary

Problems solved by technology

However, under the condition of high concentration of algae in the source water, regardless of whether the concentration is carried out by means of filter capsules / filter elements or membrane filtration, multiple filter capsules / filter elements or filter membranes are often required, which is not only troublesome in operation, but also expensive in experiments; at the same time Due to excessive precipitation, it is not conducive to the further separation and purification of Cryptosporidium oocysts and Giardia cysts, resulting in a low recovery rate

However, in the case of a large number of algae, especially in summer and autumn, the number of algae per milliliter of some water source water can reach more than ten million times, which is tens of millions of times that of the "two insects". It needs to pass through multiple filter capsules / filter elements or membranes. After enrichment and enrichment, some algae (such as Microcystis aeruginosa) are very similar in size and shape to the "two worms", and the subsequent separation and purification are difficult, which may easily lead to low recovery rate, and even autofluorescence, resulting in algae masking effect , interfere with the "two worms" microscopic examination, and cause great interference to the detection of water source water whose content of "two worms" is usually low

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