en Other Other Original article Original article <div dir="ltr"><strong><span style="font-family:garamond,serif;"><span style="font-size:10.0pt;">Introduction: </span></span></strong><span style="font-family:garamond,serif;"><span style="font-size:10.0pt;">The nematophagus fungi have been suggested as an alternative way to eliminate the zoonotic helminths eggs from the environment. In the present study, we evaluated the ovicidal activity of a fungus, <em>Paecilomyces lilacinus</em>, recovered from a compost soil, on the eggs of parasitic helminths under <em>in vitro</em> condition. <strong>Methods: </strong>Water suspension of the soil samples collected from different areas of Iran were transferred to 2% water-agar culture media baited with <em>Rhabditis </em>sp. larvae. The larvae-infecting fungi were harvested on potato dextrose agar (PDA) media. The sequencing of a beta-tubulin gene identified the nematophagus fungi as <em>P. lilacinus</em>. Eggs of three helminth species, <em>Syphacia obvelata, Hymenolepis diminuta</em> and<em> Echinococcus granulosus </em>were exposed to one isolate of the recovered fungi, and the ovicidal activity was monitored for up to 21 days. <strong>Results:</strong> Out of 300 samples, only three compost soils, contained the nematophagus fungus<em> P. lilacinus</em>. Microscopical examinations revealed invasion of the helminths eggs by the <em>P. lilacinus</em>. The eggs of<em> H. diminuta</em> were more vulnerable to this fungus invasion while <em>E. granulosus </em>eggs were the least affected ones (<em>P</em><0.05). <strong>Conclusion: </strong><em>Paecilomyces lilacinus</em> can grow on fresh feces and attack the eggs of the parasitic helminths. Therefore, a combination of its hyphae with feces or administration of the spores in the animals&rsquo; food may reduce the helminths eggs in the environment and consequently intervene with the transmission of parasitic helminthes in the animal houses.</span></span></div> Nematophagous, Paecilomyces lilacinus, Syphacia obvelata, Hymenolepis diminuta, Echinococcus granulosus 52 56 http://jommid.pasteur.ac.ir/browse.php?a_code=A-10-140-1&slc_lang=en&sid=1 Faezeh Najafi faezeh_najafi@yahoo.com No Department of Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran Saied Reza Naddaf snaddaf_2001@yahoo.com No Department of Parasitology, Research Center for Emerging and Reemerging Diseases Pasteur Institute of Iran, Tehran, Iran Sasan Rezaie srezaie@tums.ac.ir No Department of Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran Eshrat Beigom Kia molaviva@tums.ac.ir No Department of Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran Gholamreza Mowlavi molaviva@tums.ac.ir Yes Department of Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran