Free-living amoebae (FLA) of the genus Acanthamoeba are 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, in the present study, the investigation of Acanthamoeba genotypes isolated from the oral cavity of hemodialysis patients of reference hospitals in Iran was aimed, using both morphology and molecular (sequence-based analysis) tools. Furthermore, classification of the strains at the genotype level was performed on the basis of differences in the diagnostic fraction 3 (DF3) region of the 18S rRNA gene. The pathogenic potential of the isolated amoebae was also determined using thermotolerance and osmotolerance assays. Out of the 187 oral cavity samples investigated, nine (4.8%) were positive for FLA. DNA sequencing of the ASA.A1 region of the 18S rRNA gene revealed that the isolated strains belonged to the Acanthamoeba T1 and T4 genotypes. Genotype T1 was isolated for the first time from a patient in Iran. Interestingly, the T1 strain (AN2 strain) exhibits a high pathogenic potential in tolerance assays. The pathogenicity assay revealed that five strains were able to grow at high temperatures (37-40 °C) and high osmolarity (0.5 and 1 M D-mannitol) conditions; thus, they were considered as potentially pathogenic strains. Moreover, two of the patients were positive for Vermamoeba genus. The present study is the first report of genotype T1 isolation in Iran and the first to identify the occurrence of Acanthamoeba and Vermamoeba genera in patients undergoing hemodialysis worldwide. Monitoring hemodialysis and renal failure patients should be a priority for possible control of Acanthamoeba and other FLA-related diseases.

Background: Nosocomial infections are one of the health problems of modern societies, which are rising with unusual organisms. Acintobacter, which is the main cause of nosocomial infections such as pneumonia and nosocomial pneumonia, is caused by mechanical ventilation. Acinetobacter species are becoming resistant to antibiotics. One the most important agent of nosocomial infections with high mortality is infections by Acinetobacter baumannii which is Gram-negative opportunistic Coccobacilli. Treatment in these infections is difficult and sometimes impossible, due to multidrug resistance in strains isolated from nosocomial infections. Objectives:The aim of the current study was to evaluate antibiotic resistance in A. baumannii isolates Khatam-Al-Anbia Hospital, Tehran, Iran. Methods: In this cross-sectional study 100 of Acintobacter baumannii were isolated from hospitalized patients during 2013-2015 in Khatam-Al-Anbia hospital in Tehran. In this study samples of A. baumannii isolated from trachea, blood, urine, sputum and wound samples of patients bedridden in Intensive care unit (ICU) wards. Antimicrobial susceptibility and minimum inhibitory concentration (MIC) were determined by E-test methods. We used descriptive statistics to analyze the data by using SPSS 21 software. Results: A total of 100 A. baumannii were isolated from clinical samples. The organism was resistant to rifampicin (46%), gentamicin (67%), meropenem (100%), piperacilin (98%), colistin (0%), and ceftazidin (96%). Conclusions:The antibiotic resistance against most of the antibiotics especially meropenem is very high in this study. Moreover, colistin was most effective antibiotic to be used in A. baumannii infections. Colistin is the best choices for treatment of Acinetobacter.

Background: Over the past decade, Enterococci have been shown to be an important cause of nosocomial and community-acquired infections. Inappropriate use of antibiotics led to changes in the pattern of antibiotic resistances in Enterococcus species. Unfortunately, no study has been performed in Iran in recent years regarding the antimicrobial resistance of Enterococci using the E-test method as a base. We must gain sufficient knowledge about the regional antibiotic resistances related to Enterococcus so that we can monitor the prevalence and antimicrobial resistance of Enterococcus by administering appropriate treatments. Objectives: The objective of this study was to evaluate the antimicrobial susceptibility among Enterococcus species by the E-test method at Khatam-ol-Anbia hospital during 2013 -2014. Patients and Methods:This descriptive cross-sectional study was carried out during 2013 -2014. All clinical samples were collected from the intensive care unit (ICU) and general wards of Khatam-ol-Anbia hospital. All Enterococcus species were detected via biochemical testing. Antimicrobial susceptibility and minimum inhibitory concentration (MIC) were determined via disk diffusion and the E-test method. We used descriptive statistics to analyze the data. Results: A total of 53 Enterococci were isolated from clinical samples of blood, urine, wounds, sputum, and cerebrospinal fluid (CSF) over a two-year period from the ICU and general wards. The isolated Enterococcus species were 77.35% E. faecalis, 18.86% E. faecium, and 3.77% other species. Species evaluated by E-test were resistant to imipenem, ampicillin, co-trimoxazole, gentamicin, rifampicin, vancomycin, linezolid, and teicoplanin; 54%, 68%, 100%, 93.8%, 60.4%, 39.6%, 0%, and 29.2%, respectively. Among the strains of enterococci, 90.9% of E. faecium and 20% of E. faecalis species were resistant to vancomycin. Conclusions: According to these findings, antibiotic-resistance patterns have changed, and vancomycin resistance, especially among E. faecium, is rising because of nosocomial infections. Consequently, it has become a serious subject for patients admitted into a hospital.

Infection is a significant cause of morbidity and mortality in patients with chronic kidney disease, especially who were under dialysis due to their depressed immunity. Toxoplasma gondii is a ubiquitous parasite that causes severe manifestations in immunocompromised patients. This case-control study was conducted to the immunodiagnosis and molecular validation of T. gondii infection among patients with end-stage renal disease undergoing haemodialysis. The study population consisted of 260 haemodialysis patients and 259 healthy controls referred to the main dialysis centres of Tehran, Iran during 2016. Anti-T. gondii immunoglobulin G (IgG) and immunoglobulin M (IgM) antibodies were assessed using enzyme-linked immunosorbent assay. As well, the T. gondii genomic DNA in whole blood samples of IgM-positive patients and healthy controls was evaluated using GRA6-polymerase chain reaction (PCR) and SAG1-loop-mediated isothermal amplification (LAMP) assays. The anti-T. gondii IgG and IgM antibodies were detected in 175 (67.3%) and 18 (7%) of haemodialysis patients and 122 (47%) and 4 (1.5%) of controls, respectively. Two of the 18 blood samples from IgM-positive patients and none of the IgM-positive control subjects were positive by GRA6-PCR. Whereas, nine and two blood samples of IgM-positive patients and controls were positive for Toxoplasma DNA by a SAG1-LAMP technique respectively. The seropositivity of the Toxoplasma IgM antibody was significantly different between haemodialysis patients and healthy controls which was confirmed by PCR and LAMP. The higher prevalence of T. gondii infection in haemodialysis patients compared with the controls proposes that these patients can be a group at risk for toxoplasmosis and screening for toxoplasmosis before dialysis is necessary for the patients.

Background: Noroviruses are one of the major viral pathogens responsible for gastroenteritis. Outbreaks of diarrhea due to Norovirus have been reported frequently. This study is performed to determine the prevalence of Norovirus in fecal specimens of children with gastroenteritis. Many viruses can cause gastroenteritis, including Rotaviruses; Adenoviruses types 40 and 41; Sapoviruses; and Noroviruses. Current techniques used for detection of Noroviruses in stool samples include multi-step viral RNA extraction and purification followed by reverse transcriptase-polymerase chain reaction (Rt-PCR). Objectives: The purpose of this study is to detect Norovirus in stool samples by Rt-PCR in 5 different centers in Iran. Patients and Methods: In this study, 2,170 stool samples were collected from children less than five years old from five different cities, all of whom had acute gastroenteritis. Detection of Noroviruses was performed through Rt-PCR. The mean age of the studied population was 48 months. Fecal specimens were collected within 24 hours of admission. The specimens were frozen, sent to the laboratory, and then stored at -70° C until being tested for Norovirus. Results: Rt-PCR was performed for 2,170 stool samples containing 90 (4.14%) Norovirus positive (0.97% Tehran, 0.64% Tabriz, 0.18% Mashhad, 1.57% Shiraz, 0.78% Bandar Abbas). The RT-PCR was validated with published primers for Norovirus (JV12/JV13). In both retrospective and prospective settings, the Rt-PCR was equally sensitive (95%) and specific (95%) in detecting Norovirus. Conclusions: Noroviruses, which are important human pathogens, may cause epidemic acute viral gastroenteritis which in turn can be easily detected by molecular methods.