Detection of Giardia intestinalis in water samples collected from natural water reservoirs and wells in northern and north-eastern Poland using LAMP, real-time PCR and nested PCR Anna Lass, Beata Szostakowska, Krzysztof Korzeniewski and Panagiotis Karanis ABSTRACT Giardia intestinalis is a protozoan parasite, transmitted to humans and animals by the faecaloral route, mainly through contaminated water and food. Knowledge about the distribution of this parasite in surface water in Poland is fragmentary and incomplete. Accordingly, 36 environmental water samples taken from surface water reservoirs and wells were collected in Pomerania and Warmia- Masuria provinces, Poland. The 50 L samples were ltered and subsequently analysed with three molecular detection methods: loop-mediated isothermal amplication (LAMP), real-time polymerase chain reaction (real-time PCR) and nested PCR. Of the samples examined, Giardia DNA was found in 15 (42%) samples with the use of LAMP; in 12 (33%) of these samples, Giardia DNA from this parasite was also detected using real-time PCR; and in 9 (25%) using nested PCR. Sequencing of selected positive samples conrmed that the PCR products were fragments of the Giardia intestinalis small subunit rRNA gene. Genotyping using multiplex real-time PCR indicated the presence of assemblages A and B, with the latter predominating. The results indicate that surface water in Poland, as well as water taken from surface wells, may be a source of Giardia strains which are potentially pathogenic for humans. It was also demonstrated that LAMP assay is more sensitive than the other two molecular assays. Anna Lass Beata Szostakowska Department of Tropical Parasitology, Institute of Maritime and Tropical Medicine in Gdynia, Medical University of Gdansk, 9b Powstania Styczniowego Str., Gdynia 81-519, Poland Anna Lass Panagiotis Karanis (corresponding author) State Key Laboratory of Plateau Ecology and Agriculture, Center for Biomedicine and Infectious Disease, Qinghai Academy of Animal Sciences and Veterinary Medicine, Medical School of Qinghai University Xining, 1#Weier Road, Qinghai Biological Scientic Estate Garden, Xining 810016, P. R. China E-mail: panagiotis.karanis@uk-koeln.de Krzysztof Korzeniewski Epidemiology and Tropical Medicine Department in Gdynia, Military Institute of Medicine in Warsaw, Grudzinskiego St. 4, Gdynia 81-103, Poland Key words | environment, genotype, Giardia, LAMP, nested PCR, real-time PCR INTRODUCTION Giardia intestinalis is a protozoan parasite causing gastroin- testinal diseases in humans and animals worldwide (Karanis & Ey ; Smith et al. ; Reynolds et al. ; Ryan & Cacciò ). It has been estimated that ingestion of as few as ten cysts can lead to the development of infection in humans and animals (Rendtorff ). The clinical manifes- tation of giardiasis includes severe diarrhoea, abdominal cramps, nausea, weight loss, and an acute phase which usually lasts a few weeks and which may develop into a chronic recurring disease (Wolfe ; Farthing ; Adam ; Lebwohl et al. ). The prevalence of Giardia infections in humans was previously estimated at 25% in industrialised countries and 2030% in developing countries (Thompson & Monis ). However, regarding Europe, the epidemiology report from ECDPC in 2014 conrmed 17,278 giardiasis cases, reported by 23 countries in the EU/EEA, with the highest number of cases reported by Germany (n ¼ 4,011), followed by the United Kingdom (n ¼ 3,628), which accounted for 44% of cases (ECDPC ). This parasite is transmitted by the faecaloral route, through contaminated water and food (Karanis et al. ; Yoshida et al. ; Baldursson & Karanis ; Efstratiou et al. ). The presence of Giardia cysts in water is a problem throughout the world. They are resistant to 775 © IWA Publishing 2017 Journal of Water and Health | 15.5 | 2017 doi: 10.2166/wh.2017.039 Downloaded from https://iwaponline.com/jwh/article-pdf/15/5/775/393515/jwh0150775.pdf by guest on 23 May 2020