Comparative evaluation of flotation techniques for the detection of soil borne parasites

Abstract

Efficacy of the three conventional flotation techniques in recovering the parasitic forms from soil samples was compared after screening both naturally contaminated and experimentally seeded soil samples. and oocysts of Eimeria spp. and were processed by these techniques. Irrespective of parasitic species or concentration, the mean recovery rate of parasitic stages obtained was above 50 ± 4.32, above 33.67 ± 5.084 and below 22.33 ± 2.37 percent by O'Lorcain (1994), Kazakos (1983) and Santarém et al. (2009) methods, respectively. O'Lorcain (1994 method was found better than the other methods for the isolation of soil borne parasitic stages but none of these methods were found to be cent per cent sensitive.

Detecting and enumerating soil-transmitted helminth eggs in soil: New method development and results from field testing in Kenya and Bangladesh

“…As hookworm larvae hatch from eggs in the soil rather than in the human large intestine, we could expect to detect both eggs and larvae in the soil. Two studies that used sieving, centrifugation, and flotation steps similar to our protocol recovered hookworm eggs from seeded soil samples [ 4 , 7 ]. In one of these studies, 58% of the samples contained only larvae [ 4 ].…”

“…Flotation methods can vary based on the flotation solution and the flotation time. Many flotation solutions have been used, including magnesium sulfate [ 4 – 6 ], zinc sulfate [ 7 – 9 ], sodium nitrate [ 10 ], sugar [ 11 – 16 ], and salt [ 17 ]. Magnesium sulfate has been recommended by the US Environmental Protection Agency (US EPA) for detection of Ascaris in wastewater and biosolid samples [ 6 ].…”

Potentials and challenges in the isolation and detection of ascarid eggs in complex environmental matrices

“… Ascaris spp. n.d. a 10 g 100 Santarem et al, 2009 ZnSO₄ saturated 1.2 none 9.5 Gnani Charitha et al, 2013 200 5.42 10 g 100 O'Lorcain, 1994 NaNO 3 saturated 1.35 Tween® 80 n.d. 66.5 200 79.59 10 g 100 Kazacos, 1983 NaNO 3 saturated 1.35 Tween® 40 n.d. 47 200 53.83 A. suum clay 1 g 20 CFT b ZnSO₄ 1.2 water 10.6 David, 1977 1 g 20 CFT ZnSO₄ 1.2 NaOH 0.1 N 27.9 Ascaris spp. loam 15 g 1000 U.S. EPA, 2003 ZnSO₄ 7X® 1% 37.2 Steinbaum et al, 2016 A. suum loam 15 g 931 U.S. EPA, 2003 initial ZnSO₄ 1.2 Tween® 80 0.10% 37.2 Steinbaum et al, 2017 ...…”

Parasitosis intestinales en poblaciones del Cinturón Hortícola Platense, Buenos Aires: factores socio-económicos y ambientales en la evaluación de estrategias de control

“…A pesar de esto, el Índice Kappa de Cohen mostró una concordancia moderada en el uso de estas técnicas. Esto muestra que el filtrado seriado con poros de diferente diámetro previa centrifugoflotación (Shurtleff & Averre, 2000) es más eficiente que la centrifugo-flotación directa (Gnani-Charitha et al, 2013) y que la solución saturada de sacarosa (δ: 1,3 g/ml) permitió una mejor concentración parasitaria que la solución saturada de nitrato de sodio (δ: 1,4 g/ml).…”

“…El suelo de cultivo y el suelo recuperado de las raíces de las hortalizas se dejaron secar durante 2-3 días al aire libre y se procedió a realizar dos técnicas de recuperación parasitaria (Shurtleff & Averre, 2000;Gnani-Charitha et al, 2013).…”