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Flap endonuclease 1 (FEN1) is a structure-specific nuclease that plays a role in DNA replication and genome stability. FEN1 is overexpressed in proliferative cancers and correlates with the grade and aggressiveness of the cancer, suggesting that it could potentially be considered a promising biomarker for various cancer types. Due to the initiation of cancer is related to the lack of the activity of FEN1 nuclease, the detection and quantification of FEN1 is significance for cancer diagnosis in early stage. There are various approaches to detect the different types of cancer biomarkers. In this context, biosensing platforms and nanotechnology-based methods have attracted much attention. To date, the sensitivity and performance of biosensors can enhance by nanomaterials/nanoparticles that have been incorporated in biosensing platforms. This review overview a brief classification and description of the advancement of biosensors and nanobiosensors for the detection and quantitation of FEN1 based on optical and electrochemical platforms.

Abstract Background Cryptosporidium spp. are opportunistic intestinal protozoans with global distribution and are of great importance as zoonotic protozoans are common to humans and domestic animals, including cattle and calves. Identification and detection of parasite species using precise methods including molecular methods can be an effective step in treating and controlling parasites. Objectives This study aimed to investigate the prevalence of Cryptosporidium among breeding calves of Khorramabad city, Lorestan province, Western Iran, using PCR. Methods The faecal samples were taken from 181 healthy and diarrhoeal calves and after the Ziehl Neelsen Acid‐fast staining and microscopic evaluation, the genomic DNA was extracted for molecular evaluations. To detect Cryptosporidium species, specific primers targeting the SAM‐1 gene of Cryptosporidium and a commercial master mix were used for PCR. Results Out of 181 faecal samples of breeding calves in Khorramabad city, 9 samples (5%) were positive for Cryptosporidium spp. using the PCR method. Statistical analysis of the data showed that there was no significant statistical relationship between Cryptosporidium infection of the calves and variables of age, breed, type of water consumption, clinical signs of diarrhoea, and sampling location, while parasite infection had a significant relationship with calf gender so that all Cryptosporidium positive samples were from male calves (p ≤ 0.05). Conclusions Considering the presence of Cryptosporidium infection, the region's traditional grazing system, and the close relationship between livestock and humans, there is a possibility of human infection in the region. So preventive measures such as periodic animal testing with sensitive and accurate diagnostic techniques including PCR, pharmacological treatment of livestock, water hygiene and the use of industrial grazing instead of traditional grazing to improve the hygiene of food consumed by livestock are recommended.

Background: Acanthamoeba spp. is opportunistic amoeba that resides in water, soil, and air. Some pathogenic genotypes of the genus of Acanthamoeba can cause granulomatous amoebic encephalitis (GAE) in people with a defective immune system. The parasite can also cause Acanthamoeba keratitis (AK) among contact lens users. This study was conducted to isolate and identify the Acanthamoeba genotypes in water resources in Lorestan province, western Iran. Methods: Collected 72 water samples from surface and groundwater (springs and aqueducts) in Lorestan province. Samples were filtered and cultured in non-nutrient 1.5% agar medium covered with Escherichia coli (E. coli) at 25 °C. DNA extraction was done and the PCR reaction was performed to detect the Acanthamoeba spp. The positive PCR products were sequenced to determine the genotypes of Acanthamoeba. Results: Out of 72 examined water samples, 23.61% were positive for Acanthamoeba sp. by PCR. From PCR-positive samples, 8 (47.05%) samples were T4 genotypes and others were other Acanthamoeba genotypes (T1-T23). Therefore, approximately half of the genotypes belong to the pathogenic T4 genotype. Conclusions: The water examined samples in western provinces of Iran have the potential risk factor for public health. Therefore, the efforts of healthcare providers are needed to identify, train, and prevention from human infections.

Free-living amoebae (FLA) thrive in diverse environmental conditions. The present study aimed to define the FLA distribution from the Caspian Sea as well as from hospital ward dust from Guilan, Iran. Seawater (20) and hospital ward dust samples (100) were collected from May to June 2018. Seawater samples were vacuum filtered through a 0.45 μm pore-size membrane. Dust was collected using sterile gauze, washed with sterile distilled water, with washings collected thereafter. Washings were similarly filtered as seawater samples. FLA from the filtered material was cultivated in non-nutrient agar. Molecular analysis was performed by PCR and sequencing using specific primers for Acanthamoeba, Naegleria, and Vermamoeba/Hartmanella. Culture and PCR returned 50 and 65% positivity, respectively, for seawater samples where sequencing revealed Acanthamoeba T2, T5 and T6 genotypes and A. palestinensis and A. lenticulata, as well as N. dobsoni and N. clarki. In addition, 30% amoebic growth and 16% PCR detection were observed from hospital ward dust samples where sequencing revealed Acanthamoeba T2, T4 and T11 genotypes and A. castellanii, A. palestinensis and A. stevensoni as well as N. clarki. For both seawater and dust samples, Acanthamoeba was the dominant isolate. The detection of potentially pathogenic FLA from seawater may pose a threat to the public, while the presence of the same in dust spells threats to both hospital staff and patients, in particular, immunocompromised individuals. Public education, awareness, improved sanitation and hygiene, and the crafting of diagnostic strategies for the early detection of FLA in humans are necessary for the mitigation and management of potential human infection cases. HIGHLIGHTS Free-living amoebae (FLA) detected in environmental and infrastructure-derived samples.; Pathogenic genotypes of FLA detected in the Caspian Sea.; Pathogenic FLA detected in hospital wards for immunocompromised patients.; Pathogenic genotypes of FLA detected in hospital ward dust.; Hygiene and policies are necessary to protect humans against FLA infections.;

Background: Cryptosporidium species are recognized as important gastrointestinal pathogens. This study was conducted to identify the prevalence, clinical manifestations and genotyping of Cryptosporidium spp. in patients with gastrointestinal illnesses (GIs) in western Iran. Methods: Overall, 1301 fecal samples were collected from patients with GIs referred to the 12 clinical laboratories in Nahavand County, west of Iran. Modified Ziehl-Neelsen staining method was used to identify the oocysts. DNA was extracted from positive samples and Cryptosporidium spp. were characterized by Nested PCR and sequence analysis of the 60-kDa glycoprotein (gp60) gene. Data analysis was performed using SPSS ver. 16. Results: Prevalence of cryptosporidiosis was 1.3% (17/1301). Cryptosporidium infection was significantly associated with vomiting and nausea (P=0.001, OR=0.013; CI 95%=0.004- 0.044), abdominal pain (P=0.018, OR=0.073; CI 95%=0.008- 0.633) and diarrhea (P=0.001, OR=0.092; CI 95%=0.023- 0.362). Of the 17 isolates typed, 11 belonged to the C. parvum IId subtype family (subtypes IIdA26G1 and IIdA20G1) and six belonged to the C. parvum IIa subtype family (subtypes IIaA15G2R1 and IIaA16G3R1). There was no significant difference between subtype families IIa and IId in occurrence of clinical symptoms (P= 0.75). Conclusion: Improved hygiene and avoidance of contact with animals and contaminated soil should be advocated to reduce the occurrence of Cryptosporidium infections, especially in children.

We studied the prevalence of intestinal parasites (IPs), their risk factors and associated symptoms among patients with gastrointestinal disorders. A total of 1,301 participants aged 22 days-90 years were enrolled in this study. We used a structured questionnaire to obtain socio-demographic and stool examination to investigate intestinal parasite infections. Data analysis was performed using SPSS16. The overall prevalence of intestinal parasites (IPs) was 32.2% (419/1,301). Three hundred and fifty nine cases/1,301 (27.6%) were infected with a single parasite and 60/1,301 cases (4.6%) presented polyparasitism. The most common IP was Blastocystis sp. 350/1,301 (26.9%), followed by Entamoeba coli 38/1,301 (2.92%), Giardia lamblia 30/1,301 (2.3%) and Cryptosporidium spp. 17/1,301 (1.3%). Regarding the socio-demographic variables, educational status (p = 0.001), contact with domestic animals and soil (p = 0.02), age above 15 years (p = 0.001) and seasons (p = 0.001) were significantly associated to intestinal parasitic infections. Concerning clinical characteristics, the presence of IPs was significantly associated to diarrhea (OR = 1.57; CI 95% = 1.24-1.98; p < 0.001) and dysentery (OR = 1.94; CI 95% = 1.03-3.66; p < 0.04). Our findings suggest that IPs are one of the main causal agents of gastrointestinal disorders. Improving the knowledge on local risk factors such as poverty, low level of education, poor sanitation, contact with soil and contact with domestic animal is warranted.

Background: Entamoeba moshkovskii and E. dispar are impossible to differentiate microscopically from the pathogenic species E. histolytica. Multiplex polymerase chain reaction (Multiplex PCR) is a widespread molecular biology technique for amplification of multiple targets in a single PCR experiment. Methods: For detection and differentiation of the three-microscopy indistinguishable Entamoeba species in human, multiplex PCR assay using different DNA extraction methods was studied. A conserved forward primer was derived from the middle of the small-subunit rRNA gene, and reverse primers were designed from signature sequences specific to each of these three Entamoeba species. Results: A 166-bp PCR product with E. histolytica DNA, a 580-bp product with E. moshkovskii DNA and a 752-bp product with E. dispar DNA were generated in a single-round and multiplex PCR reaction. Conclusion: We recommend this PCR assay as an accurate, rapid, and effective diagnostic method for the detection and discrimination of these three Entamoeba species in both routine diagnosis of amoebiasis and epidemiological surveys.

Background: The present study was carried out to describe the epidemio-logical aspects of gastrointestinal helminthic infections of canids in Chahar-mahal and Bakhtiari Province, the central western part of Iran. Methods: Forty nine canid species including, dogs, jackals, foxes and wolves were included in this study. The contents of their alimentary canal were in-spected in order to isolate and identify the parasitic helminthes of this system. To identify the worms, the Soulsbey and Anderson identification key and light microscopy were used. Results: Based on necropsy findings, 35 (71.4%( of examined animals were infected with at least one helminth. The prevalence of identified worms was as follows: Mesocestoides lineatus (55.1%), Joyeuxiella echinorinchoides (26.5%), Tae-nia hydatigena (12.2%), T. multiceps (8.2%), T. ovis (2%), Dipylidium caninum (2%) and Spirura spp. (2%). No significant difference was noticed between the sam-pling areas, age and helminth infection. Only a significant difference was ob-served for prevalence of T. multiceps in wolf (25%), dog (21.4%), jackal and fox (0%) respectively (P < 0.05). Conclusion: The canids in Chaharmahal and Bakhtiari harbor several para-sites that some kind of them have zoonotic importance and may pose a threat to community health specially in rural areas.