The event of mutations in the surface antigen gene of hepatitis B virus (HBV) results in undetectable hepatitis B surface antigen with positive/negative anti-hepatitis B core (anti-HBc) antibody status in serum and this phenomenon is named occult hepatitis B infection (OBI). The presence of anti-HBc antibody in serum is an important key for OBI tracking, although about 20% of OBI cases are negative for anti-HBc antibody. The diagnosis of OBI is mainly based on polymerase chain reaction (PCR) and real-time PCR assays. However, real-time PCR is a more reliable method than PCR. OBI is a great issue for the public health problem and a challenge for the clinical entity worldwide. The persistence of OBI may lead to the development of cirrhosis and hepatocellular carcinoma. With regard to OBI complications, the screening of HBV DNA by the highly sensitive molecular means should be implemented for: (1) patients with a previous history of chronic or acute HBV infection; (2) patients co-infected with hepatitis C virus/human immunodeficiency virus; (3) patients undergoing chemotherapy or anti-CD20 therapy; (4) recipients of organ transplant; (5) blood donors; (6) organ transplant donors; (7) thalassemia and hemophilia patients; (8) health care workers; (9) patients with liver related disease (cryptogenic); (10) hemodialysis patients; (11) patients undergoing lamivudine or interferon therapy; and (12) children in time of HBV vaccination especially in highly endemic areas of HBV. Active HBV vaccination should be implemented for the close relatives of patients who are negative for OBI markers. Thus, the goal of this review is to evaluate the rate of OBI with a focus on status of high risk groups in different regions of the world.

Developing improved tuberculosis (TB) diagnostics is one of the international research priorities, as TB remains globally a major health threat. Loop-mediated isothermal amplification (LAMP) is a new nucleic acid detection method that can be used in low-resource settings, because it does not require expensive or complex instruments. Using the repetitive insertion sequence IS6110 as a target gene, we developed an efficient LAMP assay, which specifically detects members of the Mycobacterium tuberculosis complex (MTBC). This assay proved 20 times more sensitive than IS6110-based conventional PCR. Moreover, its sensitivity was, respectively, 50 and 20 times higher than the one obtained with the two previously described LAMP assays for M. tuberculosis, based on gyrB and rrs, respectively. Identical sensitivities were obtained for LAMP and nested PCR, but the LAMP assay was more rapid and cost-effective than the latter. Although, our LAMP assay can successfully be performed using a non-denatured template, this results in a 200-fold reduction in the sensitivity of the assay. Moreover, by performing our LAMP assay on 15 clinical sputum samples from TB patients we were able to detect MTB. Taken together, our preliminary results indicate that IS6110-based MTBC-LAMP assay is a promising new TB-diagnostic test, with high sensitivity and that could easily be applied for the diagnosis of TB in a low-resource setting.

L. crispatus appears to inhibit the entry of the virus into cells by trapping HSV-2 particles. In addition, formation of L. crispatus microcolonies in the cell surface could block HSV-2 receptors and prevent viral entry to cells in initial infection steps.

This study aims to determine the genotypes of hepatitis C virus (HCV) among blood donors at Ahvaz Blood Transfusion Centre. Blood samples were taken from 2376 blood donors - 1795 (75.54%) male and 581(24.45%) female - who referred to Ahvaz Blood Transfusion Centre during 2007-2008. Detection of anti-HCV antibody for all the donors was carried out by ELISA and the confirmatory RIBA tests. HCV RT-PCR followed by RFLP test was carried out for anti-HCV positive samples. Out of 2376 blood donors, only 55 (2.3%) male donors showed to be positive for HCV antibody by ELISA and RIBA tests out of which 45(1.8%) donors were positive for RT-PCR test. Female donors were negative for HCV antibody. The result of HCV genotyping by RFLP test showed 24 (53.3%) for 1a, 17 (37.7%) for 3a (a) and 4 (8.8%) for 3a (b) genotypes respectively. In conclusion, high prevalence of 53.3% HCV 1a genotype was observed among blood donors in Ahvaz city.

Background:BK virus (BKV) belongs to the human Polyomaviridae and the primary BKV infection is occurred during childhood then the virus could be latent through life, especially in the kidneys and urinary system. It became reactive after an immunocompromised status, such as pregnancy or transplantation. Isolated BKV from different locations of the world is grouped into four subtypes using serological and genotyping methods. The BKV subtype I is the dominant one and has worldwide distribution.Objectives:According to our knowledge, there are no data about the BKV prevalence and its genotypes in southwest part of Iran. Considering the high prevalence of renal failure and kidney transplant patients in this part, and the role of BKV in graft rejection, this study aimed to determine the prevalence of BKV infection in renal transplant recipients referred to Golestan Hospital in Ahvaz City, Iran.Patients and Methods:Urine samples were collected from 122 kidney transplant recipients referred to Golestan Hospital in Ahvaz, southwest of Iran. The extracted DNA was amplified by Polymerase Chain Reaction, and subtype of each positive sample was determined using Restriction Fragment Length Polymorphism (RFLP) and sequencing methods.Results;From all study population, 51/122 (41.8%) urine samples were positive for BKV DNA and the other samples were negative (71/122). Forty-eight cases (94.11%) were subtype I and 3 others (5.89%) were subtype IV using the RFLP method. None of the patient’s urine samples were positive for subtypes II and III.Conclusions:Our work is the second study in Iran and considering huge numbers of transplantation in Iran and Khuzestan Province, south western of Iran, in addition to the role of this virus in kidney transplant rejection, routine evaluation of BKV positivity is recommended both for graft recipient and donors. This helps better transplantation result and may prevent graft rejection.

The aim of this study was to design a high density multiepitope protein, which can be a promising multiepitope vaccine candidate against Hepatitis E virus (HEV). Initially, conserved and antigenic helper T-lymphocyte (HTL) epitopes in the HEV capsid protein were predicted by in silico analysis. Subsequently, a multiepitope comprising four HTL epitopes with high-affinity binding to the HLA molecules was designed, and repeated four times as high density multiepitope construct. This construct was synthesized and cloned into pET-30a (+) vector. Then, it was transformed and expressed in Escherichia coli BL21 cells. The high density multiepitope protein was purified by Ni-NTA agarose and concentrated using Amicon filters. Finally, the immunological properties of this high density multiepitope protein were evaluated in vitro. The results showed that the high density multiepitope construct was successfully expressed and purified. SDS-PAGE and Western blot analyses showed the presence of a high density multiepitope protein band of approximately 33 kDa. Approximately 1 mg of the purified protein was obtained from each liter of the culture media. Moreover, the purified multiepitope protein was capable of induction of proliferation responses, IFN-γ ELISPOT responses and IFN-γ and IL-12 cytokines production in a significant level in peripheral blood mononuclear cells (PBMCs) isolated from HEV-recovered individuals compared to the control group. In conclusion, the newly produced multiepitope protein can induce significant T helper type 1 responses in vitro, and can be considered as a novel strategy for the development of HEV vaccines in the future.

Background:Chronic hepatitis B virus (HBV) infection has a broad spectrum of manifestation, ranging from silent carrier state to advanced cirrhosis and hepatocellular carcinoma. The persistence of HBV DNA in serum and hepatocytes of the cirrhotic patient could be detected by molecular techniques in spite of negative HBV serologic markers.Objectives:This case-control study was designed to evaluate the prevalence of occult HBV infection (OBI) in patients with cryptogenic liver cirrhosis in comparison with healthy subjects.Patients and Methods:Of 165 patients with liver cirrhosis, 50 consecutive patients with cryptogenic cirrhosis and 80 healthy individual without any risk factors as a control group were enrolled in this study. Their sera were tested for HBV DNA using nested PCR method.Results:Of 50 patients with cryptogenic cirrhotic, 36 (72%) were male. The mean age of patients was 53.34 ± 14.73 years; 80 healthy subjects were selected as control group with mean age of 32.65 ± 8.51 years; 7 (14%) of the patients with cryptogenic cirrhosis showed positive HBV DNA by PCR, while HBV DNA was negative for the control group (P = 0.0001); 4 (57%) cases with positive HBV shown by PCR were negative for anti-HBc and anti-HBs tests. The mean level of transaminases was significantly higher in patients with cirrhosis. There were no significant differences in demographic parameters, transaminases level and degree of hepatic failure among cirrhotic patients with and without OBI.Conclusions:The prevalence of OBI was relatively high in patients with cryptogenic cirrhosis. OBI was found among the patients above 40 years old. Prospective cohort studies are needed to evaluate the clinical significance of OBI.

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