Entamoeba histolytica in Different Water Sources of Niğde Province of Turkey

Acta Parasitologica https://doi.org/10.1007/s11686-024-00886-z ORIGINAL PAPER Entamoeba histolytica in Different Water Sources of Niğde Province of Turkey Cemal Candan1 · Mustafa Karatepe2 · Bilge Karatepe2 Received: 15 March 2024 / Accepted: 30 July 2024 © The Author(s) 2024 Summary Purpose This study was carried out to determine the presence of Entamoeba histolytica in water sources of Niğde province in Turkey, between June and November 2021. Methods A total of 90 water samples were taken from 15 different water sources (drinking water, well water, spring water, wastewater and dam water) every month and the presence of E. histolytica antigens in the samples was examined by ELISA. Results The positivity for E. histolytica was determined in 7 (7.7%) of 90 samples. While no antigens were found in any of the samples in June and September, E. histolytica was positive for three samples (20%) in July, one sample (6.6%) in August and October and two samples in November (13.3%). One of 24 dam samples (4.1%), 1 of 12 wastewater samples (8.3%), 1 of 12 well samples (8.3%), and 4 of 24 fountain samples (16.6%) that examined by ELISA were found positive. On the other hand, none of the examined 18 spring samples were positive. In addition, 4 (8.8%) of 45 samples that examined in summer and 3 (6.6%) of 45 samples that examined in autumn were detected positive by using ELISA. Entamoeba histolytica positivity in samples was statistically insignificant in terms of months, water resources and seasons (P > 0.05). Conclusion As a result, the presence of E. histolytica, which is an important public health problem in water sources, was determined for the first time in Niğde province of Türkiye with this study. Keywords ELISA · Entamoeba histolytica · Niğde · Turkey · Water Introduction Amebiasis is one of the protozoan diseases in the intestines caused by E. histolytica. Entamoeba histolytica is more prevalent in developing countries and is generally transmitted to humans through cysts found in feces or contaminated food and water [1]. It is estimated that approximately 10% of the world’s population is infected with this parasite, with distribution in Turkey ranging from 0 to 17% [2, 3]. While E. histolytica primarily infects humans, it can also parasitize various monkey species, dogs, cats, pigs, cattle, and rats. However, it is noted that the parasite does not form cysts Mustafa Karatepe 1 Graduate School of Natural and Applied Sciences, Department of Biotechnology , Niğde Ömer Halisdemir University, Niğde, Türkiye 2 Faculty of Science, Department of Biotechnology, Niğde Ömer Halisdemir University, Niğde, Türkiye in hosts other than humans. The parasite usually settles in the intestines of hosts but can also migrate to other organs such as the liver, lungs, brain, and spleen, causing abscesses [3–5]. Entamoeba histolytica generally causes asymptomatic infections, but in some cases, it can lead to symptoms ranging from a few watery stools to profuse bloody diarrhea. Symptoms may include foul-smelling stools, weakness, and fatigue [3, 6, 7]. The diagnosis of amebiasis is made through various laboratory analyses. The diagnosis of protozoan infections can be established through symptoms, direct microscopic examination, and methods such as ELISA and PCR. Serological tests are crucial for diagnosing amoebiasis, as the diagnostic level of the parasite remains very low, even when at least three different stool samples are microscopically examined [6, 7]. In this study, the aim was to determine the presence of E. histolytica, which is important for human health, in water samples taken from different water sources in the Niğde province of Turkey by ELISA. 13 Acta Parasitologica Materials and Methods Study Area Niğde is located at an altitude of 1,299 m in the Central Anatolia Region of Türkiye. According to the 2020 statistics, the population of Niğde city center is 230.776 people. Niğde experiences the typical continental climate of Central Anatolia, with hot and dry summers and cold and snowy winters. Rainfall is generally in the form of snow in winter and rain in the spring. The average temperatures indicate that July is the hottest month, while January is the coldest. Showers are observed in the form of heavy rain in April, May, and the early days of June. The average precipitation in the city is 0.9 mm. April has the highest rainfall with 78.5 mm, while July has the lowest with 0.2 mm. Field Study Water samples were collected from 15 different water sources every month, between June 2021 and November 2021 in the Niğde province. The samples were collected in 5 L clean plastic containers. The collected water samples included 4 from dam waters used for agricultural irrigation, 2 each from wastewater and well water, 3 from spring water, and 4 from fountains used for drinking water purposes. Laboratory Study The sample number was chosen considering these many samples were proven to represent the population adequately in previous studies [8, 9]. A total of 90 water samples were stored at 4 °C until they were processed in the laboratory. A vacuum pump filtration device with a 0.45 μm cellulose acetate membrane filter (Ø, 45 mm) was used for filtering the water samples. Subsequently, the filter was transferred to a clean tube, and 20 ml of the same water sample was added. After vortexing to remove particulate matter, the sample was centrifuged at 2500 rpm for 10 min to discard the upper portion, and the 1.5 ml sediment at the bottom was Table 1 Entamoeba histolytica presence in water sources with regard to months Months Number of Number of Positives Examined Sources Positive Samples (%) June 15 July 15 3 20 August 15 1 6.6 September 15 October 15 1 6.6 November 15 2 13.3 Total 90 7 7.7 13 transferred to an eppendorf tube and stored in a deep freezer at -20℃ until further analysis with the ELISA. ELISA (Enzyme Linked Immunosorbent Assay) A commercial ELISA kit (E. histolytica II™, TECHLAB 2001 Kraft Drive Blacksburg, VA 24060 − 6358 USA) was used to investigate the specific adhesin antigen of E. histolytica in samples collected from different water sources. The ELISA was performed following the procedure provided by the manufacturer. ELISA results were read at 450 nm wavelength using an ELISA microplate reader, MR-96 A, and the obtained values were calculated using the kit procedure. Statistical Analysis In the conducted study, the chi-square test was used for the statistical evaluation of positivity values concerning the months of water sample collection, water sources, and seasons. Therefore, the SPSS (Statistical Programme for Social Science) for Windows 24.0 Statistical Package Program was utilized. Results Out of the total 90 water samples collected from 15 different water sources in the Niğde province, the presence of E. histolytica was detected in seven samples (7.7%) through the ELISA. In Table 1, the presence of E. histolytica is given according to the months. Accord (...truncated)