TR Dizin İndeksli Yayınlar Koleksiyonu / TR Dizin Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/20.500.14365/4
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Article Citation - Scopus: 3Clinical Impact of Hepatitis C Virus Genomic Variations(Ankara Microbiology Society, 2015-10-08) Ergünay K.; Abacioglu H.; Ergünay, Koray; Abacioglu, HakanHepatitis C virus (HCV) is a globally-dispersed agent of chronic hepatitis with a significant public health threat, affecting over 110 million individuals throughout the world. The increased risk for chronicity after exposure and the lack of a protective vaccine make HCV is a leading infectious cause of cirrhosis, liver failure requiring transplantation and hepatocellular carcinoma. The replicative process and infection dynamics in the host enable HCV to generate an array of closely-related but non-identical genetic variants known as quasispecies in the infected individuals. Pathogenesis and outcome in HCV infections are directly affected by the virus genetic heterogeneity, reflected as the emergence of quasispecies in infected individuals. The evolution of these highly-diverse viral populations in the host directly influences the disease course, via providing a pool of variants capable of resuming viral replication under extrinsic and/or intrinsic selective pressures. Viral quasispecies go through several alterations during the course of the infection, and provide a background for the selection of escape mutants from the host humoral and cell-mediated immune responses and antiviral treatment. Supported by the robust next generation sequencing techniques, recent studies have provided significant insights on the genomic diversity and progression as well as on the origin and the epidemiology of HCV. This review provides an overview of the mechanisms of HCV genetic variability, and the interactions with the host, that affects clinical disease, covering viral and host determinants of humoral and cell-mediated immune responses, alterations during the early and late stages of the infection and disease progression leading to chronicity. In addition, current findings in virus evolution and epidemiology were briefly interpreted from the inter-species and population perspectives. The impact of viral genomic heterogeneity on antiviral treatment in the era of direct-acting agents is also discussed, along with an overview of current methods employed for the characterization of viral diversity.Article Citation - WoS: 2Citation - Scopus: 2Optimization of Elisa and Immunoblot Methods for the Detection of Igg Antibodies Against Old World Hantaviruses in Wild Rodents(Ankara Microbiology Soc, 2016-04-07) Polat, Ceylan; Karatas, Ahmet; Sozen, Mustafa; Matur, Ferhat; Abacioglu, Hakan; Oktem, Mehmet Ali; Öktem, İbrahim Mehmet AliHantaviruses infect humans via inhalation of viral particles in infected rodents' secretions such as saliva, urine and faeces or via direct contact with infected rodents. The rodent species that are known as the carriers of Dobrava (DOBV), Puumala (PUUV), Saaremaa (SAAV), Tula (TULV) and Seoul (SEOV) viruses are found in our country. The presence of specific antibodies against hantaviruses have been demonstrated in rodents collected from Black Sea and Aegean Regions of Turkey in 2004 for the first time. The first hantavirus-related hemorrhagic fever with renal syndrome (HFRS) cases were reported in Black Sea region in 2009. The determination of the hantavirus prevalence in wild life and rodent populations in the field is crucial for the information about hantavirus-related cases and to clarify the state of risk. There is no commercial product optimized for the screening of rodent serum samples in terms of HFRS agents like DOBV and PUUV that are widely seen in Eurasia as well as Turkey. In this study, the antigens belonging to the commercial enzyme-linked immunoassay (ELISA) and immunoblot tests that are produced for the screening of human sera were used for the development of antibody screening tests against hantavirus in rodent sera and were optimized. The most appropriate serum and conjugate dilutions were determined for the optimization of ELISA (Anti-Hantavirus Pool ELISA; Euroimmun, Germany) and immunoblot (Euroline Anti-Hanta Profile 1 strips; Euroimmun, Germany) methods. Optimized ELISA method was used for the screening and optimized immunoblot method was used for the confirmation. A total of 84 wild rodent sera that belonged to Apodemus and Microtus species were evaluated with this procedure and the cut-off value, sensitivity and specificity of optimized ELISA method were determined. For the optimization of ELISA 1/50, 1/100 and 1/200 serum dilutions and 1/10.000, 1/20.000 and 1/40.000 conjugate dilutions were tested. For the optimization of immunoblot, 1/50 and 1/100 serum dilutions and 1/5.000 and 1/10.000 conjugate dilutions were tested. The horseradish peroxidase conjugated goat anti-mouse IgG for ELISA and the alkaline phosphatase conjugated goat anti-mouse IgG for immunoblot were used. We followed the manufacturer's recommendations for the incubation parameters, substrate and the number of washes. 1/50 serum dilution and 1/10.000 conjugate dilution for ELISA and 1/100 serum dilution and 1/5.000 conjugate dilution for immunoblot were determined as optimal concentrations. By using the optimized ELISA, 26.2% (22/84) of rodents were found positive for hantavirus antibodies according the determined cut-off value (OD450/620: 0.325). By using immunoblot as a confirmatory test, 20 out of 22 ELISA positive samples could be studied because of the insufficient amount of sera and 17 of them was found positive in terms of DOBV antibodies. Of these rodents 11 were Apodemus flavicollis, three were Apodemus agrarius, two were Microtus guentheri and one was Apodemus sylvaticus. When the results of ELISA were compared to immunoblot results, the optimized ELISA's sensitivity and specificity were found as 100% and 95%, respectively. In this study, a method that can be used in the screening of rodent sera was constituted which uses commercial antigens that can be provided easily, gives fast and reliable results. Similar serological methods optimized for different types of rodents are of great importance for the realization of active follow-up and monitoring of the studies in the field.