Preliminary Evaluation of Different Methods to Detect and Quantify Eggs in Sludge and Water Samples: A Spiking Experiment to Assess Recovery Efficiency

Overview

Journal Food Waterborne Parasitol

Date 2022 Jul 18

PMID 35844813

Authors

Sophie De Bock

Inge Van Damme

Ganna Saelens

Hang Zeng

Sandra Vangeenberghe

Sarah Gabriel

Affiliations

Soon will be listed here.

Abstract

An improved understanding of the environmental transmission of spp. is key to control of the parasite. Methods to detect and quantify eggs in different environmental matrices, including sludge and water, currently lack performance validation with regard to the recovery efficiency and process ease of use. Therefore, this study aimed to assess the recovery efficiency and process duration of commonly used methods for the detection of eggs in sludge and water samples. Ten detection methods for spp. eggs were selected from a systematic review. Sludge and water samples were spiked with a high dose of eggs, i.e., around 200 eggs/g sludge and 50 eggs/ml water, and were tested using five methods each. The two methods with the highest egg recovery efficiencies were selected per matrix for assessment with a lower spiking dose, i.e., 4 eggs/g sludge and 1 egg/ml water. Each time five replicates were used. Recovery efficiency was defined as the proportion of the number of eggs recovered to the total number of eggs spiked. Using the high spiking dose, all samples tested positive for all the methods. The mean egg recovery efficiency varied from 4% to 69% for sludge samples and from 3% to 68% for water samples. Using the lower spiking dose, one of the methods performed on sludge samples was able to detect all replicates, whereas only one replicate was positive using the other method. For water, all low dose samples tested positive using both methods. In conclusion, most methods performed inadequately in recovering eggs from sludge and water, with half of the methods performed on the high dose samples having a mean egg recovery efficiency of approximately 10% or less. The assessed recovery methods were generally time-consuming and labourious. A more thorough validation of existing recovery methods and improvement of method protocols to increase recovery efficiency is thus urgently needed.

References

Matsudo K, Inaba T, Kamiya H . Detection of Echinococcus multilocularis eggs by centrifugal flotation technique: preliminary survey of soil left in the ferryboats commuting between Hokkaido Island, where E. multilocularis is endemic, and mainland Japan. Jpn J Infect Dis. 2003; 56(3):118-9. View

Huerta M, Avila R, Jimenez H, Diaz R, Diaz J, Diaz Huerta M . Parasite contamination of soil in households of a Mexican rural community endemic for neurocysticercosis. Trans R Soc Trop Med Hyg. 2008; 102(4):374-9. DOI: 10.1016/j.trstmh.2007.12.009. View

Maganira J, Mwangonde B, Kidima W, Mwita C, Nkwengulila G, Hoglund J . Validation of droplet digital Polymerase Chain Reaction for the detection and absolute quantification of Taenia solium eggs in spiked soil samples. Acta Trop. 2019; 200:105175. DOI: 10.1016/j.actatropica.2019.105175. View

Mayta H, Gilman R, Prendergast E, Castillo J, Tinoco Y, Garcia H . Nested PCR for specific diagnosis of Taenia solium taeniasis. J Clin Microbiol. 2007; 46(1):286-9. PMC: 2224258. DOI: 10.1128/JCM.01172-07. View

Guggisberg A, Alvarez Rojas C, Kronenberg P, Miranda N, Deplazes P . A Sensitive, One-Way Sequential Sieving Method to Isolate Helminths' Eggs and Protozoal Oocysts from Lettuce for Genetic Identification. Pathogens. 2020; 9(8). PMC: 7460107. DOI: 10.3390/pathogens9080624. View

Zendejas-Heredia P, Colella V, Hii S, Traub R . Comparison of the egg recovery rates and limit of detection for soil-transmitted helminths using the Kato-Katz thick smear, faecal flotation and quantitative real-time PCR in human stool. PLoS Negl Trop Dis. 2021; 15(5):e0009395. PMC: 8153506. DOI: 10.1371/journal.pntd.0009395. View

Verbyla M, Oakley S, Mihelcic J . Wastewater infrastructure for small cities in an urbanizing world: integrating protection of human health and the environment with resource recovery and food security. Environ Sci Technol. 2013; 47(8):3598-605. DOI: 10.1021/es3050955. View

Jansen F, Dorny P, Gabriel S, Dermauw V, Johansen M, Trevisan C . The survival and dispersal of Taenia eggs in the environment: what are the implications for transmission? A systematic review. Parasit Vectors. 2021; 14(1):88. PMC: 7845101. DOI: 10.1186/s13071-021-04589-6. View

Steinbaum L, Kwong L, Ercumen A, Negash M, Lovely A, Njenga S . Detecting and enumerating soil-transmitted helminth eggs in soil: New method development and results from field testing in Kenya and Bangladesh. PLoS Negl Trop Dis. 2017; 11(4):e0005522. PMC: 5393894. DOI: 10.1371/journal.pntd.0005522. View

10.

Saelens G, Robertson L, Gabriel S . Diagnostic tools for the detection of taeniid eggs in different environmental matrices: A systematic review. Food Waterborne Parasitol. 2022; 26:e00145. PMC: 8844199. DOI: 10.1016/j.fawpar.2022.e00145. View

11.

Santos L, Rondello Bonatti T, Cantusio Neto R, Bueno Franco R . Occurrence of Giardia cysts and Cryptosporidium oocysts in activated sludge samples in Campinas, SP, Brazil. Rev Inst Med Trop Sao Paulo. 2005; 46(6):309-13. DOI: 10.1590/s0036-46652004000600003. View

12.

Schrader C, Schielke A, Ellerbroek L, Johne R . PCR inhibitors - occurrence, properties and removal. J Appl Microbiol. 2012; 113(5):1014-26. DOI: 10.1111/j.1365-2672.2012.05384.x. View

13.

Maya C, Jimenez B, Schwartzbrod J . Comparison of techniques for the detection of helminth ova in drinking water and wastewater. Water Environ Res. 2006; 78(2):118-24. DOI: 10.2175/106143005x89571. View

14.

Jimenez J, Rodriguez S, Moyano L, Castillo Y, Garcia H . Differentiating Taenia eggs found in human stools: does Ziehl-Neelsen staining help?. Trop Med Int Health. 2010; 15(9):1077-81. PMC: 3428859. DOI: 10.1111/j.1365-3156.2010.02579.x. View

15.

Wongworapat K, Keawvichit R, Putsyanant P, Khantawa B, Silprasert A, Karnchanawong S . Examination for intestinal parasites and enteric bacteria in the wastewater and treated wastewater from the city of Chiang Mai, Thailand. Southeast Asian J Trop Med Public Health. 2002; 32 Suppl 2:236-9. View

16.

Scandrett W, Gajadhar A . Recovery of putative taeniid eggs from silt in water associated with an outbreak of bovine cysticercosis. Can Vet J. 2004; 45(9):758-60. PMC: 545976. View

17.

Madera C, Pena M, Mara D . Microbiological quality of a waste stabilization pond effluent used for restricted irrigation in Valle Del Cauca, Colombia. Water Sci Technol. 2002; 45(1):139-43. View

18.

Frey C, Oakley J, Lobanov V, Marreros N, Schurer J, Lalonde L . A novel protocol to isolate, detect and differentiate taeniid eggs in leafy greens and berries using real-time PCR with melting curve analysis. Parasit Vectors. 2019; 12(1):590. PMC: 6918723. DOI: 10.1186/s13071-019-3834-8. View