Effectiveness of Cryptosporidium spp. oocysts detection and enumeration methods in water and milk samples

Abstract

Cryptosporidium spp. oocyst recovery in water and milk samples was evaluated. Samples were inoculated with a suspension of 1.2×10 7 Cryptosporidium spp. oocysts and submitted to centrifugal flotation, using different solutions (sucrose, NaCl, MgSO 4 , ZnSO 4 , AlSO 4 , NH 4 SO 4 40% and NH 4 SO 4 80%). Centrifugation of the samples was carried out in two stages for concentration using two methods that differed in the order in which the saturated solutions were used, namely only in the first stage of method I and only in the second stage of method II. Oocyst identification was performed using the Kinyoun and Koster histochemical staining techniques. Samples analyzed by method I showed different degree of oocyst recovery, namely 10.9% with NaCl and 42.5% with MgSO 4 in water and milk samples, while those samples analyzed by method II showed 10.6% with NaCl and 5.3% with sucrose in water and milk, respectively. Histochemical staining methods have no influence on the degree of oocysts recovery. The efficiency of Cryptosporidium spp. oocysts recovery methods depends on the nature and composition of the sample and on the methodology used for oocyst concentration.

Enteric Protozoa in the Developed World: a Public Health Perspective

“…Currently, the U.S. EPA and other such bodies commonly use detection methods for isolation of protozoa, from either large (up to 1,000 liters) or small (10 to 50 liters) samples, involving four sequential steps: (i) the filtration of water, resulting in the cysts or oocysts and extraneous materials being retained on the filter; (ii) the elution and separation process, involving purification and concentration of cysts or oocysts by IMS and discarding of the extraneous material; (iii) staining with specific fluorescent antibodies (FA); and (iv) enumeration using fluorescence and differential interference contrast microscopy (45,48,106,375). Other techniques that can also be used for cyst or oocyst purification purposes include density gradient, saturated-salt flotation, and continuous flow centrifugation, continuous flow filtration, and flow cytometry with cell sorting (45,251,299). Additional molecular methods are currently available for the identification of protozoa in water samples by detection of pathogen-specific genes or SSU rRNA (292,375).…”

Janela Logística De Produção De Hortaliças Orgânicas: Estudo De Caso Da Cooperativa Cooperangi – Poconé, Mt

“…Os oocistos presentes nas fezes dos hospedeiros infectados podem contaminar águas de reservatórios ou superficiais (MACHADO et al, 2006), sendo a água maiores fonte de infecção pelo coccídeo, sendo capaz de contaminar uma grande quantidade de hospedeiros, pela dispersão dos oocistos (DIAS et al, 2008).…”

A smartphone microscope method for simultaneous detection of (oo)cyst of Cryptosporodium and Giardia

“…So, lower detection in case of radish, cabbage, cucumber and carrot could be due to decreased binding affinity of the antibody to the (oo)cysts or hiding of (oo) cysts underneath the larger vegetable debris [37]. [41]. They didn't use any chemical precipitant for the flocculation of oocysts before purification steps.…”

“…Karanis et al (2001) compared different flocculants and concluded that using ferric sulfate yield a higher recovery (61.5%) of C. parvum oocysts from tap water with a very low impact on the viability of oocysts [27]. Also, no detergent solutions were included in the study that helped to set the oocysts free from the sediments [41]. In a study made by Hsu et al…”