How to isolate broncho-pulmonary nematodes? The Baermann Technique - SMARTLAB

Language: Italian - Subtitles: ENGLISH - SPANISH - FRENCH



Qualitative analysis for the examination and identification of larvae present in the faeces of farm animals and pets (bronchopulmonary nematodes and Strongyloides stercoralis).

Smartlab is a tutorial series dedicated to laboratory diagnostics and parasitology realized by the Parasitology Lab of the University of Sassari, Italy.

Materials:
- Faecal sample to be analyzed
- 1 funnel with a stopper ( a rubber stopper from test tubes is fine too)
- 1 filter
- 1 piece of gauze 20x20 cm
- 1 liquid aspirator
- 1 small funnel
- 1 test tube
- 1 laboratory centrifuge
- Pasteur pipettes
- Lugol’s dye
- Microscope slides and coverslips

Procedure: wrap a piece of faeces with gauze and place it in a funnel which has been sealed at the narrow end and in which a filter has been placed to ensure that the wrapped faeces do not obstruct the narrow part of the funnel. Fill the funnel with tap water, covering the faeces completely. Let the sample settle at room temperature for at least 12 hours. After 12 hours, remove the faeces from the funnel and aspirate the supernatant with a liquid aspirator, leaving only the liquid contained in the narrow part of the funnel. With the help of a smaller funnel, transfer the liquid into a test tube. Centrifuge the sample at 2000 rpm for 10 minutes. Remove the supernatant using a Pasteur pipette and add an equal amount of undiluted Lugol’s dye (about 2 drops) to the pellet.

Results: place a small amount of the sediment (about 50 µl) on an a microscope slide, cover it with a coverslip and examine it under a microscope. First at small magnification (10x) and in case the sample is positive, observe present larvae at higher magnification (up to at 40x) focusing on the details of the extremities for identification.

References:
NBP Cats: Giannelli, A., Capelli, G., Joachim, A., Hinney, B., Losson, B., Kirkova, Z., René-Martellet, M., Papadopoulos, E., Farkas, R., Napoli, E., Brianti, E., Tamponi, C., Varcasia, A., Margarida Alho, A., Madeira de Carvalho, L., Cardoso, L., Maia, C., Mircean, V., Mihalca, A.D., Miró, G., Schnyder, M., Cantacessi, C., Colella, V., Cavalera, M.A., Latrofa, M.S., Annoscia, G., Knaus, M., Halos, L., Beugnet, F., Otranto, D. (2017) Lungworms and gastrointestinal parasites of domestic cats: a European perspective. International Journal for Parasitology, 47 (9), pp. 517-528. DOI: 10.1016/j.ijpara.2017.02.003

NBP Dogs: McGarry, J.W., Morgan, E.R. (2009) Identification of first-stage larvae of metastrongyles from dogs. Veterinary Record, 165 (9), pp. 258-261. DOI: 10.1136/vr.165.9.258

NBP Ruminants: Van Wyk, J.A., Mayhew, E. (2013) Morphological identification of parasitic nematode infective larvae of small ruminants and cattle: A practical lab guide. Onderstepoort Journal of Veterinary Research, 80 (1). DOI: 10.4102/ojvr.v80i1.539

Strongyloides stercoralis: Paradies, P., Iarussi, F., Sasanelli, M., Capogna, A., Lia, R.P., Zucca, D., Greco, B., Cantacessi, C., Otranto, D. (2017) Occurrence of strongyloidiasis in privately owned and sheltered dogs: Clinical presentation and treatment outcome. Parasites and Vectors, 10 (1), art. no. 345. DOI: 10.1186/s13071-017-2275-5