Maryam Niyyati

Shahid Beheshti University of Medical Sciences · Department of Parasitology

Free Living Amoebae (FLA) are ubiquitous microorganisms reported from harsh environmental conditions. Oil refinery facilities consume vast volumes of water during their processes, generating a large amount of wastewater. The present study aimed to evaluate the wastewater treatment process in an oil refinery wastewater treatment facility (ORWWTF) fo...

Free-living amoebae (FLA) including Acanthamoeba spp., Naegleria fowleri, and Balamuthia mandrillaris are among the many waterborne parasites. There is not much known about the possible FLA contamination of the irrigation resources watering crops and agricultural lands in this country. Forty-five water samples were collected from water canals used...

Naegleria species (spp.) is a free‐living amoebae whose pathogenic species such as N. fowleri pose a significant health risk to young people and the most important source of infection is water source. This study aims to perform a systematic review and meta‐analysis of the data on the prevalence of Naegleria spp. in water sources of the available li...

Intestinal microsporidiosis is known as an opportunistic infection in immunocompromised patients. The current study aimed to investigate intestinal microsporidia infection in human subjects with/without immunodeficiency. Totally, 600 stool samples were collected from immunocompromised (254) and immunocompetent (346) subjects. DNA extraction was per...

Background: Blastocystis is a protozoan parasite living in the intestine of humans and a wide range of animals. Although Blastocystis grows in several cultivation media, axenification and serial cultivations for long time are the main challenges of the researchers. Therefore, the long-term storage of subtypes/strains of Blastocystis using cryopres...

Blastocystis is a prevalent parasite that has a wide distribution. In order to design HRM real-time PCR, primers were selected from SSU rRNA gene to amplify specific fragment with different melting temperatures for each subtype of Blastocystis. Subsequently, HRM real-time PCR was performed and melting curve analysis was done by Rotor-Gene Q softwar...

The burden of HIV/AIDS in Iran is not as high as in the other countries with high prevalence; however, the number of cases of HIV/AIDs is increasing in this region. According to a recent report, Iran had 5000 (1400–13,000) new cases of HIV infection with 4000 (2500–6200) AIDS-related deaths. Individuals affected by HIV/AIDS are highly susceptible f...

Purpose Free-living amoeba (FLA) including Acanthamoeba spp., Balamuthia mandrillaris, and Naegleria are among the soil-born parasites. There are reports of FLA-related keratitis with a history of contact with soil and dust sources, particularly among the farmers. Due to lack of the previous studies on the farmland soils and a limited number of res...

Treated wastewater samples were collected, filtered using sterile 47-mm cellulose nitrate membrane and DNA extracted from the filtered materials. The presence of Blastocystis sp. was confirmed via PCR targeting the SSU rRNA gene of Blastocystis sp. in 5/12 of samples. Based on the subtype analysis after sequencing, 2, 2 and 1 of ST2, ST6 and ST8 we...

Background: The present study aimed to assess the grouping of subtypes 1-3 and 6 of Blastocystis according to the size and generation time of the parasite among the symptomatic and asymptomatic subjects. Methods: Blastocystis subtypes1-3 and 6 isolated from symptomatic and asymptomatic subjects and were cultivated in DMEM medium. In order to assess...

Free-living amoebae belong to the genus Acanthamoeba; can feed on microbial population by phagocytosis, and with the capability to act as a reservoir and a vehicle of microorganisms to susceptible host. Therefore, the role of endosymbiosis in the pathogenesis of Acanthamoeba is complex and not fully understood. The aim of the present study was to i...

Aim The aim of the present study was to simultaneously investigate parasitic contamination of treated wastewater and downstream vegetable farms that are irrigated with treated sewage, during a year. Background (Oo) Cysts and eggs of parasites are resistant to most of routine wastewater treatment process. Irrigation of vegetables farms with either...

Background: The main aim of the present research was to develop the experimental meningo encephalitis due to Naegleria australiensis isolated from geothermal water sources in mice model, November 2017 in Iran. Methods: Naegleria australiensis was isolated from geothermal water sources in northern Iran. The number of amoebae was adjusted to be 1×...

Background & objectives: Ilam province is one of the oldest known endemic foci of zoonotic cutaneous leishmaniasis (CL) in Iran; and the recent studies have shown an increasing trend in the number of cases from the region. This study was aimed to investigate the parasite species and genetic diversity of isolates obtained from CL patients based on t...

Background The presence of potentially pathogenic Free Living Amoebae (FLA) in hospital environment could be a health hazard for high-risk patients such as immunosuppressed patients. This study was carried out to investigate the presence of potentially pathogenic FLAs in the environment and medical instruments of different hospital wards, and nasal...

Blastocystis is a prevalent eukaryotic microorganism that has been frequently reported from the stool samples of human and animals, all over the world. The prevalence of this parasite has close correlation with the climate and hygiene situation of studied populations. For the current study, English and Persian databases were searched for the follow...

Acanthamoeba keratitis (AK) is a sight-threatening infection of the cornea disease that often presents with a lengthy and not fully effective treatment. Current therapeutic options against Acanthamoeba are not very effective against the cyst. Calibrated trophozoite/cyst suspension was incubated with the same volume of serial dilutions of the Trigon...

Background: This study aimed to investigate the anti-Acanthamoeba effects of the most used marketed disinfecting solutions in Iran. Moreover, the efficacy of some nano-compounds was tested against pathogenic Acanthamoeba. Methods: The present study was conducted in the School of Public Health, Tehran University of Medical sciences, Tehran, Iran...

Background Human-infecting microsporidia are a group of spore-forming eukaryotic microorganisms that can infect both animals and humans. Recent evidences indicate waterborne transmission of microsporidia spores to human via either drinking water or irrigation of vegetable farms with contaminated water resources. The current study aimed to evaluate...

Background: Acanthamoeba spp. are opportunistic amphizoic protozoans, which are distributed in the natural and artificial environment water sources. This ubiquitous amoeba is the causative agent of Amoebic Keratitis(AK) and Granulomatous Amoebic Encephalitis(GAE). The main aim of the current study was to identify the presence of Acanthamoeba spp. I...

3rd International &10th National Congress of Parasitology &Parasitic Diseases of Iran (NICOPA10)

AbstractFree-living amoebae (FLA) of the genus Acanthamoebaare opportunistic pathogenic agents able to cause life-threatening infections in immunosuppressed patients. Chronic kidney disease impairs adaptive and innate immunity. Thus, patients with chronic kidney disease are prone to opportunistic infections by potentially pathogenic FLA. Therefore,...

Background Acanthamoeba spp. is potentially pathogenic free-living amoeba that can exist in various water sources. The presence of this amoeba in water sources could be a health hazard as Acanthamoeba could lead to severe diseases such as Acanthamoeba keratitis and encephalitis. This study aimed to determine the genotypes of isolated Acanthamoeba s...

h i g h l i g h t s g r a p h i c a l a b s t r a c t From the 80 water samples, 16 (20%) were positive for the outgrowth of free living amoebae. Of 34 municipal water, 7 were positive for outgrowth of Vermamoeba, Naegleria and Acanthamoeba. Balamuthia mandrillaris was unde-tected in all the water samples. a b s t r a c t The present study tested 8...

Objective: To verify phylogeography and genetic structure of Acanthamoeba populations among the Iranian clinical isolates and natural/artificial environments distributed in various regions of the country. Methods: We searched electronic databases including Medline, PubMed, Science Direct, Scopus and Google Scholar from 2005 to 2016. To explore t...

Cutaneous leishmaniasis (CL) is one of the most important vector-borne parasitic diseases, highly endemic in Iran, and its prevalence is increasing all over the country. Arginase (ARG) activity in isolated Leishmania parasites from CL patients is yet to be explored. This study aimed to compare the ARG activity of isolated Leishmania promastigotes f...

The present study tested 80 samples of municipal, geothermal and recreational water samples for the occurrence of waterborn free living amoebae (FLA) including Acanthamoeba, Balamuthia mandrillaris, Vahlkampfiids and Vermamoeba in Semnan province, North half of Iran. Four sets of primers including JDP1,2 primers, ITS1,2 primers (Vahlkampfiids), 16S...

Proliferation of Leishmania (L.) parasites depends on polyamine availability, which can be generated by the L-arginine catabolism and the enzymatic activity of arginase (ARG) of the parasites and of the mammalian hosts. In the present study, we characterized and compared the arginase (arg) genes from pathogenic L. major and L. tropica and from non-...

A multiple alignment of ARG proteins between Leishmania parasites and mammalian. ARG protein sequences from human, mice and various Leishmania species were aligned. The C-terminal tripeptide (SKL and AKL) signature for glycosomal localization in Leishmania parasites is highlighted with the rectangle box. The alignment was applied by using Clustal W...

Phylogenetical relationships between old and new world Leishmania spp. and mammalian arg genes using maximum likelihood (ML) algorithm. The written numbers next to the each branch are computed from bootstrap values of 500 replicates. The evolutionary tree was created by user-friendly MEGA 5.05. The retrieved GenBank nucleotide sequences analysed ar...

Background Acanthamoeba is an opportunistic amphizoic protozoan found in different fresh water sources. The aim of this study was to identify and characterize Acanthamoeba isolates from surface resting waters, in Northwest Iran. Methods Samples were collected from twenty-two different areas, between May and Sep 2014. After filtration, samples were...

Potentially pathogenic Free-Living Amoebae include members belonging to Naegleria genus. The species N. fowleri is known worldwide as the causative agent of the lethal Primary Amoebic Meningoencephalitis (PAM). Only one clinical case of N. fowleri has been reported in Iran. Several species of Naegleria have been reported to be natural carriers of o...

Acanthamoeba genus includes pathogenic species which are causal agents of a severe sight-threatening infection of the eye known as Acanthamoeba keratitis (AK). Furthermore, the number of AK is worryingly increasing worldwide, mostly in contact lens users. Until present, there is a general failure to reach a fully effective treatment against AK whic...

Opportunistic infections due to free-living amoebae such as Granulomatous Amoebic Encephalitis (GAE), cutaneous acanthamoebiasis and disseminated infections could be the causative agent of mortality in people living with HIV/AIDS. In this study, we report the occurrence of the Acanthamoeba belonging to the T4 genotype isolated from nasal and oral s...

Aim: The aim of the present study was to determine the prevalence of intestinal parasites and their relation with socio-demographic data in referred individuals to the medical centers in Tonekabon, Mazandaran province, 2015. Background: Due to the climatic and ecological conditions in Mazandaran province, determination of the status of intestina...

Background Toxoplasma gondii is an obligate, intracellular protozoon that develops its sexual stage in cat’s intestinal epithelial cells as definitive host and develops its asexual stage in different tissues of a wide range hosts called intermediate host. The protozoon is a food-borne and worldwide parasite that can cause serious complications such...

Background Leishmaniasis is a zoonotic disease caused by species of protozoa of the genus Leishmania. In recent years, incidence of cutaneous leishmaniasis has increasing trend in Golestan Province, North of Iran. The aim of the present study was to identify the frequency of cutaneous leishmaniasis using PCR-RFLP in patients referred to Kalaleh Hea...

Acanthamoeba keratitis (AK) is a sight-threating infection of the cornea that mostly affects contact lens wearers. Until now, AK treatment remains very difficult due to the existence of a highly resistant cyst stage in the life cycle of Acanthamoeba which is extremely resistant to most of the available anti-amoebic compounds. Moreover, current trea...

Acanthamoeba spp. is an opportunistic protozoan parasite which is the causative agent of granulomatous amoebic encephalitis (GAE) and Acanthamoeba keratitis (AK). GAE usually occurs in immunocompromised patients which in most cases is fatal. The present study was conducted to determine the genotypes of Acanthamoeba isolated from patients with compr...

The continuous increase in Acanthamoeba keratitis, a severe corneal infection, worldwide is mainly due to the increase in the number of soft contact lens users. In the present study, which involves a 5-year study, a total of 138 corneal scraps and contact lenses together with their paraphernalias were obtained from suspected amoebic keratitis patie...

Balamuthia mandrillaris is an opportunistic free-living amoeba that has been reported to cause cutaneous lesions and Balamuthia amoebic encephalitis. The biology and environmental distribution of B. mandrillaris is still poorly understood and isolation of this pathogen from the environment is a rare event. Previous studies have reported that the pr...

A comprehensive survey was conducted along 10 km of geothermal rivers in southwestern Iran. A total of 40 water samples were tested for the presence of Acanthamoeba spp., and genotypes were determined by targeting the diagnostic fragment 3 region of the 18S rRNA gene. The pathogenic potential of all positive isolates was also identified using toler...

The present study was conducted to evaluate the presence of potentially pathogenic free living amoebae in drinking and recreational water sources in south-western Iran. From 75 collected water samples, 40 samples (53.3%) were positive for free living amoebae identified using morphological tools. Interestingly, all recreational waters in Ilam city i...

Background: Pathogenic strains of Acanthamoeba are causative agents of a sight threating infection of the cornea known as Acanthamoeba keratitis (AK). AK cases have been raised in Iran during past years due to inappropriate usage of contact lens and most patients report a contact with contaminated sources such as dust, water or soil. Material and m...

Balamuthia mandrillaris is an opportunistic free-living amoebae (FLA) which has been reported as the causative agent of the fatal Balamuthia amoebic encephalitis (BAE). Currently, the transmission dynamics of this pathogen remain poorly understood although the organism has been associated with soils, and thus, soil exposure has been identified as a...

Protozoan parasitic diseases are endemic in many countries worldwide, especially in developing countries, where infertility is a major burden. It has been reported that such infections may cause infertility through impairment in male and female reproductive systems. We searched Medline, PubMed, and Scopus databases and Google scholar to identify th...

Pathogenic strains of Acanthamoeba are causative agents of a sight threating infection of the cornea known as Acanthamoeba keratitis. AK cases have been reported in Iran recently due to inappropriate usage of contact lens maintenance and most patients report a contact with contaminated sources such as dust, water or soil. Sixty soil samples were co...

Acanthamoeba spp. are free-living amoeba found in a wide variety of natural habitats. The high percentage of the presence of Acanthamoeba in different environmental sources represents a sanitary risk for public health, especially immunocompromised patients and contact lens wearers. Acanthamoeba can cause granulomatous amoebic encephalitis, otitis,...

Background: Naegleria spp. is a free-living amoeba of which some species including N. fowleri and N. australeinsis are highly pathogenic in human and animals. These widespread amoebae could be found in different environmental sources particularly in aquatic resources of tropical and subtropical regions. The most important source of infection is vi...

Background: Free-living amoeba (FLA)-related keratitis is a progressive infection of the cornea with poor prognosis. The present study aimed to investigates the contact lenses of patients with keratitis for pathogenic free-living amoebae. Methods: Overall, 62 contact lenses and their paraphernalia of patients with keratitis cultured and tested f...

Background: Acanthamoeba-related disease have a poor prognosis according to many previous studies. Thus researches regarding biochemical and molecular aspects of this organism are a high priority. To this end achieving high amount of amoebae in culture is the first step for such studies. The main aim of the present research was to address the usage...

Background: Protozoan parasitic diseases are endemic in many countries worldwide especially in developing countries, where infertility is a major burden. These infections can cause diminished or absent ability to conceive (infertility) due to impairment in male and female reproductive systems. Materials and Methods: Medline, PubMed, Scopus, Google...

The present study was conducted to determine the occurrence of potentially pathogenic free-living amoeba in ophthalmology wards in reference hospitals in Iran. Since an increasing number of Acanthamoeba Keratitis cases after eye surgery and eye trauma have been recently observed in this country, it could be possible that the disinfection procedures...

In the latest articles which were published during 2013-2014, Trichomonas vaginalis (T. vaginalis) was mentioned as a neglected sexual transmission disease (STD), while the exact mechanism of its pathogenesis has not been cleared yet. Although trichomonasiasis is easy curable, there is concern that resistance to drug are increasing. This common inf...

Acanthamoeba- related infections, such as amoebic keratitis and granulomatous amoebic encephalitis, can develop in high-risk population through contaminated water sources. Thus, surveying water resources, particularly those available for human use, is of the utmost importance. In the present study, 67 water samples were collected from water resourc...

Free-living amoebae (FLA) are unicellular protozoan parasites widely spread in a variety of natural habitats, including dust, lakes, rivers, swimming pools, thermal baths, tap water, sources of waters receiving industrial refuse, sewage, as well as fluids or tissue from healthy human oropharynx. Presence of FLA in these environments is a hygienic r...

Amoebic keratitis, a sight-threatening corneal infection, mainly occurs in contact lens wearers who wash their eyes with tap water. The present research was conducted to identify the occurrence of potentially pathogenic free-living amoebae (FLA) in tap water sources on Kish Island, a tourist region in Iran. Amoebae were detected using a culture-enr...

Background: Acanthamoeba keratitis (AK) is potentially a sight-threatening infection and its treatment is challenging. This is mainly due to presence of resistant cyst form. Indeed, cysts are highly resistant to current available drugs. Chemical drugs are toxic to human keratocytes. It should also be mentioned that most available anti-Acanthamoeba...

Free-living amoebae belonging to the genus Acanthamoeba have an environmental distribution. Amoebic keratitis due to these protozoan parasites continue to rise in Iran and worldwide. In Iran, there are various researches regarding both morphological and molecular identification of Acanthamoeba spp. in environmental and clinical samples. However, th...

Acanthamoeba- bacteria interactions enable pathogenic bacteria to tolerate harsh conditions and lead to transmission to the susceptible host. The present study was aimed to address the presence of bacterial endosymbionts of Acanthamoeba isolated from recreational water sources of Tehran, Iran. To the best of our knowledge this is the first study re...

ABstrAct Free living amoebas are widespread protozoans that can be found in different environmental resources such as water bodies, soil and clays. Free living amoebae particularly Acanthamoeba could lead to diseases with poor prognosis including ameobic keratitis (AK) and granulomatous amebic encephalitis (GAE) especially in contact lens wears and...

Abstract: Free living amoebas are widespread protozoans that can be found in different environmental resources such as water bodies, soil and clays. Free living amoebae particularly Acanthamoeba could lead to diseases with poor prognosis including ameobic keratitis (AK) and granulomatous amebic encephalitis (GAE) especially in contact lens wears an...

ABstrAct Free living amoebas are widespread protozoans that can be found in different environmental resources such as water bodies, soil and clays. Free living amoebae particularly Acanthamoeba could lead to diseases with poor prognosis including ameobic keratitis (AK) and granulomatous amebic encephalitis (GAE) especially in contact lens wears and...