Occurrence of Acanthamoeba Genotypes in Wastewater Samples in Tehran, Iran.

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 spp. in raw wastewater samples in Tehran, Iran. METHODS: Overall, 90 raw wastewater samples were collected from water treatment facilities in west and south of Tehran, Iran during 2014-2016. Water samples were filtered and cultured on non-nutrient agar (NNA) medium enriched with Escherichia coli. Morphological and molecular analyses were done on positive strains. The pathogenic ability of the isolated strains was determined using physical assays. RESULTS: Totally, 6 out of 90 (6.7%) samples were positive for Acanthamoeba, according to morphological characteristics of double-walled cysts. Genotyping and sequencing of the positive strains showed Acanthamoeba belonging to T4 (83%) and T11 (17%) genotypes. In vitro pathogenicity tests were revealed that five isolates were classified as non-pathogenic strains and one strain belonging to T4 genotype was classified as the highly pathogenic amoebae. CONCLUSION: The current research reflected a low contamination of wastewater sources to Acanthamoeba. More studies regarding the contamination of wastewaters before and after treatment are required in different places of the country.

Isolation and genotyping of Acanthamoeba strains (T4, T9, and T11) from amoebic keratitis patients in Iran.

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 patients. All samples were cultured using culture-enrichment method. Pathogenic assay, using thermotolerance and osmotolerance tests were also performed on the positive strains. Sequencing of the isolated strains was done by targeting the DF3 region of 18s rRNA gene. The results revealed that 18 (13 %) of patients were infected with Acanthamoeba spp. As expected, T4 genotype was the most common genotype among the clinical samples; however, in three cases, Acanthamoeba belonging to T11 and T9 were detected. Interestingly, T9 genotype, commonly classified as non-pathogenic amoebae, was identified as a causal agent of a patient with amoebic keratitis. From the pathogenic assay, four strains belonging to T4 genotypes were highly pathogenic. This is the first report of Acanthamoeba T9 genotypes isolated in Iran and the first report of T9 type occurring in amoebic keratitis patients worldwide. Due to the increasing trend of amoebic keratitis (AK) and the identification of new genotypes, such as T9 as the causative agent of AK, more researches in this field are necessary in the region and the world at large.

Prevalence of Intestinal Parasitic Infections in Jiroft, Kerman Province, Iran.

BACKGROUND: Intestinal parasitic infections have a worldwide distribution. High prevalence of intestinal parasitic infections in individuals with low socioeconomic status and environmental conditions was found. No study has ever been conducted on the prevalence of these infections in Jiroft. Therefore, in this study prevalence of intestinal parasitic infections was evaluated in Jiroft, Kerman Province, Iran. METHODS: A total of 1060 individuals from rural and urban areas of Jiroft were sampled accidentally, during 2013-2014. Fresh stool samples were collected from all individuals and examined by formalin ether concentration and agar plate culture. Direct examination was performed on watery samples. RESULTS: Out of 1060 individuals, 563 (53.1%) and 497 (46.9%) people were from rural and urban areas, respectively. In general, 297 individuals (28%) were infected with intestinal parasites. The prevalence of infection for protozoa and helminthes infections were 27.4% and 1.8%, respectively. The most prevalent protozoans were Blastocystis hominis (13.7%) and Giardia lamblia (7.8%), and that of helminth was Hymenolepis nana (1.1%). CONCLUSION: Intestinal protozoan parasites were more prevalent than helminth parasites. Source of water supply and personal hygiene were important factors in the distribution of parasites in the study area.

Detection of Emergence Cyclospora cayetanensis in A HIV(+) / AIDS Patient with Diarrhea from Tehran: A Case Report.

Coccidian protozoa of Cyclospora cayetanensis are obligate intracellular apicomplexan parasites that infect the mucosal epithelium of the small intestine of immunocompetent and immunocompromised persons. A 25- years old woman from around, Tehran with complaint of faintness and fatigue with HIV positive/AIDS confirmed eight months ago was admitted in Imam Khomeini Hospital, Tehran, Iran in 2014. The patient suffered from intestinal and lung symptoms like watery diarrhea, flu-like symptoms. The stool was examined by direct preparation and concentration technique, stained with modified acid-fast staining method, and observed with light and then Immunofluorescence microscope. The stool cultivation was made in dichromate potassium medium and diagnosis of Cyclospora infection was finally made according to observation of Cyclospora oocysts almost 10 µm in acid-fast staining method and autofluorescence of Cyclospora under Immunofluorescence microscope. The patient was initially treated with azithromycin, tazocin and fluconazol because of lung lesions and diarrhea and relative remission was observed. Cyclospora sp. causes an intestinal infection particularly in immunocompromised patients.

Comparison of three staining methods for the detection of intestinal microspora spp.

BACKGROUND: This study aimed to compare three staining methods including: Calcofluor white, Chromotrope and Quick Hot Gram chromotrope used in diagnosis of intestinal microsporidial spores. METHODS: One hundred and seventy five stool specimens were collected from patients referred to Laboratory of Intestinal Protozoology at the School of Public Health, Tehran University of Medical Sciences during 2012-2013. All of specimens were evaluated by nested PCR. The formalin-fixed stool samples were prepared from each specimen and dried at room temperature for 10 min, followed by 10 min methanol fixation. All the collected stool samples were evaluated blindly by calcofluor white, Chromotrope and Quick Hot Gram chromotrope staining methods separately. RESULTS: Microsporidial spores were recognized using Chromotrope, Quick Hot Gram chromotrope and Calcofluor white, in16 of 18 (88.8%), 17 of 18 (94.4%) and 18 of 18(100%) samples that were positive by nested PCR respectively. Regarding 14 stool samples that were negative by nested PCR, 14 cases were negative by chromotrope and Quick hot Gram chromotrope and 13 samples were negative by Calcofluor white. One discordant sample interpreted as false positive. CONCLUSION: Calcofluor white staining had the best performance for the detection of intestinal Microsprora spores and can be used as initial screen test for the detection of intestinal Microspora spp.