Fluorescent bioassay for SARS-CoV-2 detection using polypyrene-g-poly(ε-caprolactone) prepared by simultaneous photoinduced step-growth and ring-opening polymerizations.

The construction of a rapid and easy immunofluorescence bioassay for SARS-CoV-2 detection is described. We report for the first time a novel one-pot synthetic approach for simultaneous photoinduced step-growth polymerization of pyrene (Py) and ring-opening polymerization of ε-caprolactone (PCL) to produce a graft fluorescent copolymer PPy-g-PCL that was conjugated to SARS-CoV-2-specific antibodies using EDC/NHS chemistry. The synthesis steps and conjugation products were fully characterized using standard spectral analysis. Next, the PPy-g-PCL was used for the construction of a dot-blot assay which was calibrated for applications to human nasopharyngeal samples. The analytical features of the proposed sensor showed a detection range of 6.03-8.7 LOG viral copy mL-1 (Ct Scores: 8-25), the limit of detection (LOD), and quantification (LOQ) of 1.84 and 6.16 LOG viral copy mL-1, respectively. The repeatability and reproducibility of the platform had a coefficient of variation (CV) ranging between 1.2 and 5.9%. The fluorescence-based dot-blot assay was tested with human samples. Significant differences were observed between the fluorescence intensity of the negative and positive samples, with an overall correct response of 93.33%. The assay demonstrated a high correlation with RT-PCR data. This strategy opens new insights into simplified synthesis procedures of the reporter molecules and their high potential sensing and diagnosis applications.

Rapid Point-of-Care COVID-19 Diagnosis with a Gold-Nanoarchitecture-Assisted Laser-Scribed Graphene Biosensor.

The global pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus has revealed the urgent need for accurate, rapid, and affordable diagnostic tests for epidemic understanding and management by monitoring the population worldwide. Though current diagnostic methods including real-time polymerase chain reaction (RT-PCR) provide sensitive detection of SARS-CoV-2, they require relatively long processing time, equipped laboratory facilities, and highly skilled personnel. Laser-scribed graphene (LSG)-based biosensing platforms have gained enormous attention as miniaturized electrochemical systems, holding an enormous potential as point-of-care (POC) diagnostic tools. We describe here a miniaturized LSG-based electrochemical sensing scheme for coronavirus disease 2019 (COVID-19) diagnosis combined with three-dimensional (3D) gold nanostructures. This electrode was modified with the SARS-CoV-2 spike protein antibody following the proper surface modifications proved by X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) characterizations as well as electrochemical techniques. The system was integrated into a handheld POC detection system operated using a custom smartphone application, providing a user-friendly diagnostic platform due to its ease of operation, accessibility, and systematic data management. The analytical features of the electrochemical immunoassay were evaluated using the standard solution of S-protein in the range of 5.0-500 ng/mL with a detection limit of 2.9 ng/mL. A clinical study was carried out on 23 patient blood serum samples with successful COVID-19 diagnosis, compared to the commercial RT-PCR, antibody blood test, and enzyme-linked immunosorbent assay (ELISA) IgG and IgA test results. Our test provides faster results compared to commercial diagnostic tools and offers a promising alternative solution for next-generation POC applications.

Investigation of drug resistance against protease, reverse transcriptase, and integrase inhibitors by next-generation sequencing in HIV-positive patients.

Our aim was to investigate the mutations in protease (PR), reverse transcriptase (RT), and integrase (IN) gene regions in human immunodeficiency virus (HIV) using a single amplicon via next-generation sequencing (NGS). The study included plasma samples from 49 HIV-1-positive patients, which were referred for HIV-1 drug resistance testing during 2017. A nested polymerase chain reaction (PCR) was performed after the RNA extraction and one-step reverse transcription stages. The sequencing of the HIV genome in the PR, RT, and IN gene regions was carried out using MiSeq NGS technology. Sanger sequencing (SS) was used to analyze resistance mutations in the PR and RT gene regions using a ViroSeq HIV-1 Genotyping System. PCR products were analyzed with an ABI3500 GeneticAnalyzer (Applied Biosystems). Resistance mutations detected with NGS at frequencies above 20% were identical to the SS results. Resistance to at least one antiretroviral (ARV) drug was 22.4% (11 of 49) with NGS and 10.2% (5 of 49) with SS. At least one low-frequency resistance mutation was detected in 18.3% (9 of 49) of the samples. Low-frequency resistance mutations resulted in virological failure in only one patient. The cost of the analyses was reduced by sample pooling and multiplex analysis using the MiSeq system. This is the first study in Turkey to use NGS technologies for the detection of resistance mutations in all three gene (PR, RT, IN) regions using a single amplicon. Our findings suggest that NGS is more sensitive and cost-effective than the SS method.

Demographic, clinical, and laboratory features of COVID-19 in children: The role of mean platelet volume in predicting hospitalization and severity.

There have been a limited number of studies on coronavirus disease 2019 (COVID-19) in children. In this study, we aimed to investigate the demographic, clinical, and laboratory features of COVID-19 and to identify the role of mean platelet volume (MPV) in predicting the prognosis in children. A single-center retrospective study, including 251 confirmed and 65 suspected COVID-19 cases, was conducted between March 11, 2020, and December 11, 2020. In the confirmed COVID-19 group, 48 (19.1%) patients were asymptomatic, 183 (72.9%) mild, 16 (6.4%) moderate, 1 (0.4%) severe, and 3 were (1.2%) critically ill. Confirmed COVID-19 patients had significantly lower mean values of white blood cell (WBC), absolute neutrophil count, absolute lymphocyte count, platelet, and hemoglobin (p < .001). However, there was no significant difference in MPV levels between the two groups (p = .894). C-reactive protein (CRP), procalcitonin, fibrinogen, and NT-pro-BNP mean values were significantly lower in confirmed COVID-19 cases than suspected cases (p < .001). A total of 55 (21.9%) patients required hospitalization due to COVID-19, and MPV, WBC, CRP, procalcitonin, D-dimer, and NT-pro-BNP were statistically higher in hospitalized patients than those in outpatients. The multivariate analysis of confirmed COVID-19 cases according to the severity of disease showed that lymphopenia and higher levels of fibrinogen significantly associated with severe clinical symptoms. Decision tree analysis showed that the most powerful predictor of hospitalization due to COVID-19 was the D-dimer (p < .001). MPV values are not associated with COVID-19 disease severity. However, MPV can be used with other parameters such as WBC, CRP, procalcitonin, D-dimer, and NT-pro-BNP to predict hospitalization.

Simple workflow to repurpose SARS-CoV-2 swab/serum samples for the isolation of cost-effective antibody/antigens for proteotyping applications and diagnosis.

Supply shortage for the development and production of preventive, therapeutic, and diagnosis tools during the COVID-19 pandemic is an important issue affecting the wealthy and poor nations alike. Antibodies and antigens are especially needed for the production of immunological-based testing tools such as point-of-care tests. Here, we propose a simple and quick magnetic nanoparticle (MNP)-based separation/isolation approach for the repurposing of infected human samples to produce specific antibodies and antigen cocktails. Initially, an antibody cocktail was purified from serums via precipitation and immunoaffinity chromatography. Purified antibodies were conjugated onto MNPs and used as an affinity matrix to separate antigens. The characterization process was performed by ELISA, SDS-PAGE, electrochemistry, isothermal titration calorimetry, and LC-Q-TOF-MS/MS analyses. The MNP-separated peptides can be used for mass spectrometry-based as well as paper-based lateral flow assay diagnostic. The exploitation of the current workflow for the development of efficient diagnostic tools, specific treatments, and fundamental research can significantly impact the present or eventual pandemic. This workflow can be considered as a two birds, one stone-like strategy.

[Comparison of Two Anti-HIV Confirmatory Assays: Recombinant HIV 1/2 Line Immunoassay and Geenius HIV 1/2 Confirmatory Test]. / Iki Anti-HIV Dogrulama Testinin Karsilastirilmasi: Rekombinant HIV 1/2 "Line Immunoassay" ve Geenius HIV 1/2 Dogrulama Testi.

The main purpose in the diagnosis of human immunodeficiency virus (HIV) infection is to rapidly and accurately identify people with HIV infection. It is recommended that samples that are repeatedly reactive should be verified/supported according to the classical algorithms of international and national guidelines. The recombinant "line immunoassay test (LIA)", which has been used for many years, is studied with the accumulated samples to be cost and labor-effective. In this study, the supplemental recombinant HIV 1/2 LIA (INNO-LIA®, Fujirebio, Ghent, Belgium) used to confirm and differentiate the diagnosis of HIV-1 and HIV-2 infections, and an immunochromatographic supplemental test (Geenius™ (Bio-Rad Laboratories, Marnes-la-Coquette, France) which can provide faster results were compared. One hundred fifty serum samples sent to Ege University Faculty of Medicine Hospital Medical Virology Laboratory with anti-HIV 1/2 and p24 antigen positive and indeterminant results and three HIV-1 positive external quality control samples were included in the study. Samples were tested both with the Geenius™ HIV 1/2 (Bio-Rad Laboratories, Marnes-la-Coquette, France) and recombinant HIV 1/2 LIA (INNO-LIA®, Fujirebio, Ghent, Belgium). HIV 1 viral load was evaluated by using Abbott real-time HIV-1 test in Abbott m200sp system (Abbott Molecular, Wiesbaden, Germany) in plasma samples. In both assays, the results were consistent in 147 samples (96.08%). Six samples that have discordant results were as follows: one sample was LIA HIV-1 positive and Geenius indeterminate, two samples were LIA indeterminant and Geenius HIV-1 positive, and in three samples, LIA was indeterminate and Geenius negative. In two EIA reactive samples (2/97, 2.06%) and three EIA negative samples (3/53, 5.66%) LIA results were indeterminant. Geenius test, on the other hand, correctly identified HIV positive and negative samples. The immunochromatographic test could be used in the diagnostic algorithm of HIV infection, due to its short application time, not being labor intensive, its ability to distinguish HIV-1/2, its high sensitivity/specificity compared to LIA, and the compliance with LIA. However, it should be noted that in acute HIV infection, all analytical antibody tests, become reactive later than the fourth generation enzyme immunoassays.

HEV seroprevalence in blood donors in Turkey by two commercial total anti-HEV Ab ELISA kits.

Previous hepatitis E virus (HEV) seroprevalence studies in Turkey have shown high variabilities, leading to conflicting results. We aimed to re-evaluate HEV seroprevalence among blood donors in Turkey using the Wantai (Beijing, China) and the Dia.Pro (Milan, Italy) total anti-HEV antibody (Ab) enzyme-linked immunosorbent assay (ELISA) kits and compare their performances and to investigate the presence of HEV RNA in blood donors. Serum total anti-HEV antibodies were determined in a total of 2011 volunteer blood donor samples collected from different regions of Turkey (807 from Ankara, 243 from Kayseri, 284 from Izmir, 200 from Malatya, 200 from Kahramanmaras, and 277 from Van). HEV RNA was evaluated by a real-time polymerase chain reaction in a total of 272 anti-HEV seropositive samples. The country-wide HEV seroprevalence was calculated as 11.5% (Dia.Pro) and 12.2% (Wantai) with seropositivity rates of 12.0%-12.5% in Ankara, 7.4%-8.2% in Kayseri, 14.5%-15.5% in Malatya, 8.1%-8.8% in Izmir, 15.0%-16.0% in Kahramanmaras, and 12.6%-13.4% in Van by Dia.Pro and Wantai kits, respectively. The lowest detectable Ab concentrations were 0.16 and 0.14 units/mL WHO, for the Dia.Pro and the Wantai assays, respectively, showing no significant difference between assays. HEV RNA was not detected in any of the anti-HEV seropositive samples. Compared with previous studies, HEV was shown to have a higher overall seroprevalence in Turkey. Despite its limitation, the current study represents the most comprehensive HEV seroprevalence study in Turkey performed with two different commercial ELISA assays with high sensitivities so far. Further investigation is required to determine HEV genotypes in Turkey.

Epidemiology of blood-borne viral infections in Afghanistan.

Although a few studies have been done on transmissible blood-borne viral infections in high-risk groups, little attention has been given to assessing the infection status of the general population in Afghanistan. To investigate the epidemiological status in the general population, we tested the serological markers of hepatitis B virus (HBV), hepatitis C virus (HCV), hepatitis delta virus (HDV), human immunodeficiency virus 1 (HIV-1) and human T-cell leukemia virus (HTLV) infections. In total, 492 samples were selected randomly from Nangarhar, Herat, Mazar-e Sharif, Kandahar, and Kabul from subjects between 25 and 70 years old. The samples were tested for the presence of HBsAg, anti-HBs, anti-HBc, anti-HDV, anti-HCV, anti-HIV-1 and anti-HTLV I/II antibodies using chemiluminescent immunoassays on Abbott Architect automated platforms. In addition, 220 HBsAg-positive samples identified among 5897 samples from the general population of the same regions of Afghanistan were included in the study and tested for both HBsAg and anti-HDV to investigate HDV prevalence in the country. Viral loads of HBV, HCV and HDV were determined in all seropositive samples using Ampliprep/Cobas TaqMan HBV, HCV, Test Roche (CA, USA), and an in-house method, respectively. Out of 492 samples, 31 (6.3%), 136 (27.6%) and 149 (30.3%) were found to be positive for HBsAg, anti-HBs and anti-HBc, respectively. Anti-HDV positivity was detected in five (2.1%) out of 234 HBsAg-positive samples (including 14 of the randomly selected samples that were not among the 220 previously identified as HBsAg positive). Only eight out of 492 (1.6%) subjects were positive for anti-HCV antibodies. Seven out of 489 (1.4%) were positive for anti-HIV-1 antibodies, and three out of 466 cases (0.6%) were positive for anti-HTLV I/II antibodies. These results suggest that Afghanistan is an intermediate endemic region for HBV, HDV and HCV infection. The prevalence of HIV-1 seems to be significantly higher than the global prevalence and that of the eastern Mediterranean region. In addition, the HTLV I/II screening results suggest that these viruses should be monitored in Afghanistan to confirm the trend observed in the current study.

[Analysis of hepatitis B virus (HBV) preS1, preS2 and S gene regions from patient groups infected with HBV genotype D]. / Hepatit B virüsü (HBV) genotip D ile enfekte hasta gruplarinda HBV preS1, preS2 ve S gen bölgelerinin analizi.

Mutations in preS and S gene regions of hepatitis B virus genome may cause immune escape and diagnostic escape HBV mutants. The aim of this study was to determine preS1, preS2 and S gene regions of HBV from HBV infected patient groups by sequence analysis and contribute to the relevant literature. Nucleic acid sequence analysis of preS and S genes of HBV PCR products from 56 archived plasma samples sent to Ege University Faculty of Medicine Medical Microbiology Department Molecular Virology laboratory, for HBV tests were determined by chain termination reaction. Amino acid (aa) sequences were compared with the reference sequences obtained from GenBank. Plasma samples belonged to four groups of patients: A- Chronic HBV infected patients with typical HBV serological profiles (22 samples), B- HBV infected patients with atypical HBV serological profiles (26 samples), C- HBV re-infected patients after liver transplantation (5 samples), D- Seroconversion phase following acute HBV infection (3 samples). One of two vaccine escape mutant samples was also diagnostic escape mutant; the other diagnostic escape mutant was isolated from anti-HBc positive sample. All of the sequences were determined as genotype D. HBsAg subtypes were determined as; two ayw1, six ayw3, two mix, 46 ayw2. Among the 304 codons analysed between preS 33rd and S 162nd amino acids; aa variants were determinedin 105 codons (34.5%). Sequences can be found in GenBank with accession numbers FJ001941-FJ001996. At least one aa variation was detected in 48 of 56 samples (85.7%). The amino acid variants were as follows; PreS1: A33T, A39T, P41K, D44del, D50N, T51P, D54N, L65P/M, F67L, W77T, A81S, Q82E, I84T, L85I/M, Q86H/T, L88S, A90T/V, N91K/del, A95P, S96A, T97I/A, N98K, Q100K, S101T, S109T, P110S, N114D/E, PreS2: M1V, Q2R, S5H, F8S, H9Q, Q13L, D14N, R16K, R18K, G19S/D, F22L/S, S28T, G30E, N33T, V39A, P41H/L, I42T/L, I45T, F46Y, S47L, R48K, I49T, D51V/G, P52L, A53V, L54R/G, N55K; S gene: E2D, I4F, F8L, G10A, V14A, F20S, L22del, R24K, P29L, Q30K, N40S, F41del, G44E, T45L, T46P, V47A, L49R, Q54R, P56L, S64F, P70A, M75I, C76Y, R79H, I81T, F83C, L88P, L94S, Y100F, Q101H/R, M103L, L104F, L109I/M, I110L, G112S/R, S113N/P, S114A/del, T115I, T116N, T118A/K, P120A/T, T123A, in "a" determinant; T126I, Q129H/R, T131N, M133T, Y134N, S136Y, S143L/M/T, D144E, G145A/R. Deletions were also found in all three preS/S gene regions. The highest number of aa variations were detectedin the isolated anti-HBc positive sample (in 24 codons), followed by liver transplant group (8-13 codons). Point mutation was detected in the preS2/S promoter CCAAT box. Major hydrophilic region (MHR) variants were determined in 41.1% of 56 samples. The highest number of MHR variants belonged to atypical HBV serological profile group (group B; 61.5%) and liver transplantation group with HBV re-infection (all C group). Among the diagnostic escape and immune escape mutant (anti-HBs positive) samples, reported MHR and "a" determinant mutations were detected. In conclusion, the study population carries HBV preS/S variants; MHR and "a" determinant variant rates are high among diagnostic or immune escape mutants. It is important to evaluate the mutant detection performance of HBsAg tests.

[Evaluation of viral etiology in central nervous system infections from a university hospital point of view in Izmir based on seven years data]. / Santral sinir sistemi enfeksiyonlarinda viral etiyolojinin Izmir'de bir üniversite hastanesinin yedi yillik verileri üzerinden degerlendirilmesi.

The serious diseases of the central nervous system (CNS); encephalitis and meningitis, have high mortality and morbidity rate especially not diagnosed and treated in time. Nucleic acid testing (NAT) is the tool of choice for viral diagnosis in CNS infections. In this study, viral etiological agents found in cerebrospinal fluid (CSF) samples sent to our university hospital virology laboratory for laboratory diagnosis of CNS infections were retrospectively evaluated and results were compared with other reports from our country. Viral etiological agents found in cerebrospinal fluid (CSF) samples sent to Ege University Faculty of Medicine Department of Medical Microbiology Virology Laboratories for laboratory diagnosis of CNS infection between 01.01.2009-31.12.2015 were evaluated retrospectively. A total of 3778 CSF tests were performed for cell culture of enterovirus (EV) in 487 samples and 3291 tests for nucleic acid testing (NAT) by real time polymerase chain reaction (PCR) in herpes simplex virus 1 (HSV1), herpes simplex virus 2 (HSV2), varicella zoster virus (VZV), Epstein-Barr virus (EBV), cytomegalovirus (CMV), human herpes virus 6 (HHV6) and EV. VZV and EV NAT's were performed during the last one and five years period, respectively. NAT positive results for HSV1, HSV2, CMV, EBV, VZV, HHV6 and EV were 1.80% (24/1333), 0.08% (1/1333), 3.28% (19/580), 4.35% (22/506), 0.46% (1/216), 1.05% (5/478) and 3.37% (6/178), respectively. EV was isolated in 30 (6.20%) of 487 CSF samples by viral culture. Positive samples were mainly from pediatric, neurology and infectious diseases clinics as expected. The number of higher positive results were found in samples sentin december (35.3%), july (12.9%) and november (10.6%). Overall 80% of positive samples belonged to patients over 18 years old. When the results of other studies reported from Turkey are examined, although the positivity rates are generally similar, it is seen that the rates specific to certain factors are higher in selected smaller patient groups like HSV1 and EV. Rapid nucleic acid tests like multiplex PCR and microarray will provide more practical and effective laboratory diagnosis approach in CNS infections, since many more microorganisms may be causative agents.

[Investigation of human herpesvirus-8 seroprevalence in blood donors and HIV-positive patients admitted to Ege University Medical School Hospital, Turkey]. / Ege Üniversitesi Tip Fakültesi Hastanesine basvuran kan donörlerinde ve HIV-pozitif hastalarda insan herpesvirusu-8 seroprevalansinin arastirilmasi.

Human herpesvirus 8 (HHV-8), classified in Herpesviridae family, is the etiological agent of Kaposi's sarcoma (KS), primary effusion lymphoma and multicentric Castleman's disease. In contrast to the other herpesviruses, HHV-8 seroprevalence is low in general populations; however, the higher prevalence observed in individuals with immunodeficiencies such as AIDS poses an increased risk for KS. The global distribution of HHV-8 shows great variations, with the highest seroprevalence seen in Africa. The number of studies on the seroprevalence of HHV-8 in Turkey are limited. The aim of this study was to determine the HHV-8 seroprevalences in healthy blood donors and HIV-positive patients, that will contribute HHV-8 seroepidemiological data in our country. This study was designed as a cross-sectional study. A total of 551 healthy donors (76 female, 475 male; age range: 18-65 years) admitted to Ege University Medical School Hospital, Blood Center for blood donation between December 2013-January 2014, and 173 HIV-positive patients (30 female, 143 male; age range: 18-65 years) admitted to infectious diseases outpatient clinic between October 2013-January 2014, were included in the study. A commercial ELISA method (KSHV/HHV-8 IgG ELISA Kit, Advanced Biotechnologies Inc, USA) was used for the detection of IgG antibodies that were structured against HHV-8 lytic antigens. In the study, 29 (29/551, 5.3%) of blood donors and 44 (44/173, 25.4%) of HIV-positive patients, with a total of 73 (73/724, 10.1%) cases were found as HHV-8 seropositive. The difference between blood donors and HIV-positive patients in terms of HHV-8 seropositivity rates was statistically significant (5.3% versus 25.4%; p< 0.05). In both of the study groups, no statistically significant difference was detected between HHV-8 seropositivity with gender and age. When considering HIV-positive patients, no statistically significant difference was observed between HHV-8 seropositivity with the duration of anti-HIV positivity, CD4(+) T cell count, HIV-RNA status and history of having sexually transmitted disease. As a result, HHV-8 seroprevalence rate detected in our study is similar to the data of other studies performed in Turkey, as well as the rates reported from other European and Asian countries.

[Investigation of hepatitis C virus genotype distribution in patients with chronic hepatitis C infections in Antalya Training and Research Hospital, Turkey]. / Antalya Egitim ve Arastirma Hastanesinde kronik hepatit C hastalarinin genotip dagiliminin arastirilmasi

Hepatitis C virus (HCV) infection is a major global health problem due to high chronicity rates, occurrence of severe hepatic diseases, and absence of an accurate therapy and effective vaccine. It is well known that viral genome is highly variable and HCV has at least six genotypes, each of them containing a series of subtypes. HCV genotypes exhibit geographical and epidemiological distribution. Genotype identification is clinically important to decide the dosage and duration of treatment since different genotypes exhibit variable response to treatment. The aim of this study was to determine the HCV genotypes in chronic HCV patients who were followed-up in Antalya Research and Training Hospital, Turkey. Anti-HCV and HCV-RNA positive blood samples obtained from 148 chronic hepatitis C patients (67 female, 81 male; mean age: 50.5 ± 10.8, age range: 17-73 years) who were admitted to Antalya Research and Training Hospital Microbiology Laboratory during January 2011-June 2013, were included in the study. Epidemiological data of the patients and HCV genotype results were evaluated retrospectively. Viral genotypes were determined by real-time (Rt) PCR assay (Abbott Molecular Diagnostic, USA). HCV genotype (Gt)-1 was detected in 119 (80.4%) of the patients, of them 15.9% (19/119) were identified as subtype 1a and 75.6% (90/119) were subtype 1b. The prevalence rates of Gt-2, -3, and -4 were found as 3.4% (n= 5), 11.5% (n= 17), and 2% (n= 3), respectively. Gt-6 was not detected in our patients. Mixed infection with HCV types was detected in four patients (2.7%) by Rt-PCR; of these three were detected as Gt-1 and one was Gt-2 by RFLP (Restriction Fragment Length Polymorphism) and sequencing. The high prevalence of Gt-3 (11.5%) obtained in this study was attributed to the determination of Gt-3 in seven of 13 foreign national subjects. Rt-PCR method used in this study is user independent, standardized, automated, rapid and reliable method, however in case of detection of mixed types, the samples should be confirmed by other methods. In conclusion, we reported that the majority of the chronic hepatitis C infected patients had Gt-1b, and Gt-3 exhibited the highest rate ever reported by other studies from Turkey.

[HIV-1 subtype distribution determined by phylogenetic analysis of pol gene sequences and automated subtyping tools among HIV-1 isolates from the Aegian Region of Turkey]. / Ege Bölgesi'nde izole edilen HIV-1 izolatlarinin alttip dagiliminin pol gen bölgesi filogenetik analizi ve otomatize araçlar kullanilarak belirlenmesi.

Human immunodeficiency virus (HIV) exhibiting remarkable genetic variability, includes two genotypes namely HIV-1 (group M, N, O and P) and HIV-2 (group A-H). HIV-1 group M, which is mainly the cause of the AIDS pandemic, is divided into nine pure subtypes, more than 45 circulating recombinant forms (CRF) and numerous unique recombinant forms (URF). According to the documents of Turkish Government of Health, among a total of 6802 HIV-positive cases, 1096 of them were defined as AIDS as of June 2013 in Turkey. Although subtype B is the predominant subtype, recent studies indicate higher proportion of CRFs similar to their increasing role in the HIV pandemic. The aim of this study was to determine the subtype distribution of HIV-1 strains isolated from 70 patients (61 male, 9 female; age range: 16-73 yrs, mean age: 39.6 yrs) who presented to our institution between April 2008-June 2013. HIV-1 strains were subtyped by phylogenetic analysis of the pol gene region and commonly used automated subtyping tools namely, Stanford HIV db v6.2.0 and Rega v3.0. Pol sequences retrieved from the Los Alamos database and from GeneBank, were trimmed from full-length genomes. Phylogenetic analysis of the 1302 base pair of the pol gene region was performed using Mega v5.2 software. The sequences were aligned using Muscle and phylogenetic distances between sequences were estimated by using Kimura two-parameter model (transition/transversion ratio: 2.0). Tree topology was obtained using neighbour-joining method and bootstrap value was set at 1000. Sixty-one (87.1%) patients were antiretroviral treatment (ART)-naive and nine were on different ART regimens. The subtypes of the isolates according to phylogenetic analysis were found as follows; 31 (44.2%) subtype B, 24 (34.2%) CRF42_BF, 6 (8.5%) B/CRF02_AG recombinants, 5 (7.1%) sub-subtype A1, 1 (1.4%) sub-subtype F1, 1 (%1.4) CRF 25_cpx, 1 (1.4%) CRF02_AG and 1 (1.4%) CRF01_AE. Rega v3.0 subtyping tool produced five discrepant results (4 B/CRF02-AG and 1 CRF42_BF) compared to phylogenetic analysis. Stanford HIVdb v6.2.0 had eight results (3 CRF42_BF, 2 subtype B, 2 sub-subtype A1, 1 CRF25_cpx) that were not concordant with phylogenetic analysis. Stanford HIVdb v6.2.0 was able to subtype all B/CRF02_AG recombinant strains. B/CRF02_AG recombinants which were seen among homosexual men in France were for the first time isolated in Turkey from five men (2 homosexual, 2 bisexual, 1 heterosexual) and one heterosexual woman. CRF42_BF had not been found in Turkey previously and it has not been a common type isolated in neighboring countries either. Full genome sequencing could be helpful to further analysis of those isolates. Our results support the latest studies from Turkey reporting increase in the proportion of CRF-related infections. This is not an unusual finding when geographical location of Turkey is considered. Nevertheless, more comprehensive data regarding molecular epidemiology and subtype distribution of HIV-1 isolates in Turkey are needed.

[Role of line immunoassay in the diagnosis of early HIV infection: a diagnostic case]. / Erken dönem HIV enfeksiyonunda "line immunoassay" testinin yeri: Tanisal bir olgu.

Combined p24 antigen-HIV antibody fourth-generation assays that identify most of the early HIV infections have been used extensively worldwide for several years. This poses challenges for the traditional algorithm of line immunoassay (LIA) confirmation. LIA tests are useful methods with their high specificity and their ability to differentiate HIV-1 from HIV-2, but they are reactive days after the fourth generation enzyme immunoassays. With acute HIV infection, high levels of infectious virus are detectable in serum and genital secretions. The rate of transmission during acute HIV infection is higher than the established HIV infection, for this reason, new HIV testing strategies need to focus on sensitivity, especially for this highly contagious phase immediately after infection. Serum sample of a patient sent to Ege University Hospital Clinical Virology Laboratory was repeatedly reactive with low signal/cutoff ratios with two different commercial fourth generation enzyme immunoassays (Architect HIV Ag/Ab Combo Reagent Kit, Abbott, Germany and Vidas HIV Duo Quick, Biomerieux, France). The sample was non-reactive with the LIA (INNO-LIA HIV I/II Score, Innogenetics, Belgium) and HIV RNA (RealTime HIV-I Amplification Reagent Kit, Abbott, USA) result was positive (4.1 x 10(5) copies/ml). With the presentation of this case, the role of LIA in the diagnosis of early HIV infection and its place in test algorithms were questioned.

Prevalence of Transmitted Drug Resistance among HIV-1 Patients in the Aegean Region: Results from the Western Part of Turkey.

OBJECTIVES: This study aimed to analyze the antiretroviral drug resistance in antiretroviral treatment-naïve HIV-positive patients in the Aegean Region of Turkey from 2012 to 2019. METHODS: The study included 814 plasma samples from treatment-naïve HIV-positive patients. Drug resistance analysis was performed by Sanger sequencing (SS) between 2012-2017 and by next-generation sequencing sequencing (NGS) between 2018-2019. SS was used to analyze resistance mutations in the protease (PR) and reverse transcriptase (RT) gene regions using a ViroSeq HIV-1 Genotyping System. PCR products were analyzed with an ABI3500 GeneticAnalyzer (Applied Biosystems). The sequencing of the HIV genome in the PR, RT, and integrase gene regions was carried out using MiSeq NGS technology. Drug resistance mutations and subtypes were interpreted using the Stanford University HIV-1 drug resistance database. RESULTS: Transmitted drug resistance (TDR) mutation was detected in 34/814 (4.1 %) samples. Nonnucleoside reverse transcriptase inhibitor (NNRTI), nucleoside reverse transcriptase inhibitor (NRTI), and protease inhibitor (PI) mutations were identified in 1.4 % (n =12), 2.4 % (n =20), and 0.3 % (n = 3) of samples, respectively. The most common subtypes were B (53.1 %), A (10.9%), CRF29_BF (10.6%), and B + CRF02_AG (8,2%). The most common TDR mutations were E138A (3.4%), T215 revertants (1.7%), M41L (1.5%), and K103N (1.1%). CONCLUSION: Transmitted drug resistance rate in the Aegean Region is compatible with national and regional data. Routine surveillance of resistance mutations may guide the safe and correct selection of initial drug combinations for antiretroviral therapy. The identification of HIV-1 subtypes and recombinant forms in Turkey may contribute to international molecular epidemiological data.

Characteristics of pediatric COVID-19 patients admitted to the emergency department and factors associated with pneumonia.

OBJECTIVES: Coronavirus disease 2019 (COVID-19) that causes a respiratory illness, continues to be a global pandemic. In this study, we purpose to identify the features of children with COVID-19 and the factors affecting disease severity. METHODS: This is a retrospective, observational study was conducted on patients who presented with suspicion of COVID-19 from April 1, 2020, to March 31, 2021, at a tertiary care medical center in Turkey. The characteristics of 640 children who were confirmed to have COVID-19 by real-time reverse transcription-polymerase chain reaction were retrieved from medical records. RESULTS: The mean age of the cases was 10 ± 6 years, and 56% of them were male. Seasonal difference did not affect the number of cases. The majority of the cases (n = 501, 78%) were infected by family members. Fever (67%) and cough (38%) were common complaints. The mean duration of fever was 1.9 ± 1.1 days. One-fourth of the cases were asymptomatic, 462 (72%) had mild upper respiratory tract infections, and 18 (3%) had pneumonia. Patients with pneumonia were more likely to have comorbidities and had a longer fever duration (both P < 0.001). Fever, cough, and respiratory distress were more common in patients with pneumonia (P = 0.010, P = 0.023, and P < 0.001, respectively). The mean C-reactive protein (CRP) value of the patients with pneumonia was significantly higher than that of the others (P < 0.001). A total of 70 (11%) complicated patients were hospitalized, 5 of them requiring intensive care admission. All hospitalized patients were discharged with recovery. CONCLUSIONS: Although pediatric COVID-19 patients tended to have a mild disease, some children with comorbidities can still develop a severe illness. CRP value is a useful indicator in the diagnosis of COVID-19 pneumonia. Furthermore, the prevalence rate of COVID-19 did not decrease with hot seasons.

Indiscriminate SARS-CoV-2 multivariant detection using magnetic nanoparticle-based electrochemical immunosensing.

The increasing mutation frequency of the SARS-CoV-2 virus and the emergence of successive variants have made correct diagnosis hard to perform. Developing efficient and accurate methods to diagnose infected patients is crucial to effectively mitigate the pandemic. Here, we developed an electrochemical immunosensor based on SARS-CoV-2 antibody cocktail-conjugated magnetic nanoparticles for the sensitive and accurate detection of the SARS-CoV-2 virus and its variants in nasopharyngeal swabs. The application of the antibody cocktail was compared with commercially available anti-SARS-CoV-2 S1 (anti-S1) and anti-S2 monoclonal antibodies. After optimization and calibration, the limit of detection (LOD) determination demonstrated a LOD = 0.53-0.75 ng/mL for the antibody cocktail-based sensor compared with 0.93 ng/mL and 0.99 ng/mL for the platforms using anti-S1 and anti-S2, respectively. The platforms were tested with human nasopharyngeal swab samples pre-diagnosed with RT-PCR (10 negatives and 40 positive samples). The positive samples include the original, alpha, beta, and delta variants (n = 10, for each). The polyclonal antibody cocktail performed better than commercial anti-S1 and anti-S2 antibodies for all samples reaching 100% overall sensitivity, specificity, and accuracy. It also showed a wide range of variants detection compared to monoclonal antibody-based platforms. The present work proposes a versatile electrochemical biosensor for the indiscriminate detection of the different variants of SARS-CoV-2 using a polyclonal antibody cocktail. Such diagnostic tools allowing the detection of variants can be of great efficiency and economic value in the fight against the ever-changing SARS-CoV-2 virus.

'All In One' SARS-CoV-2 variant recognition platform: Machine learning-enabled point of care diagnostics.

Point of care (PoC) devices are highly demanding to control current pandemic, originated from severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2). Though nucleic acid-based methods such as RT-PCR are widely available, they require sample preparation and long processing time. PoC diagnostic devices provide relatively faster and stable results. However they require further investigation to provide high accuracy and be adaptable for the new variants. In this study, laser-scribed graphene (LSG) sensors are coupled with gold nanoparticles (AuNPs) as stable promising biosensing platforms. Angiotensin Converting Enzyme 2 (ACE2), an enzymatic receptor, is chosen to be the biorecognition unit due to its high binding affinity towards spike proteins as a key-lock model. The sensor was integrated to a homemade and portable potentistat device, wirelessly connected to a smartphone having a customized application for easy operation. LODs of 5.14 and 2.09 ng/mL was achieved for S1 and S2 protein in the linear range of 1.0-200 ng/mL, respectively. Clinical study has been conducted with nasopharyngeal swabs from 63 patients having alpha (B.1.1.7), beta (B.1.351), delta (B.1.617.2) variants, patients without mutation and negative patients. A machine learning model was developed with accuracy of 99.37% for the identification of the SARS-Cov-2 variants under 1 min. With the increasing need for rapid and improved disease diagnosis and monitoring, the PoC platform proved its potential for real time monitoring by providing accurate and fast variant identification without any expertise and pre sample preparation, which is exactly what societies need in this time of pandemic.

Quantitative paper-based dot blot assay for spike protein detection using fuchsine dye-loaded polymersomes.

Real-time reverse transcriptase-polymerase chain reaction (RT-PCR)-based assays are the gold standard for virus diagnosis. Point-of-care (POC) technologies have shown great progress during this period. Herein, we propose a novel fuchsine dye-loaded polymersome for a colorimetric paper-based dot blot spike protein diagnostic assay for COVID-19 via smartphone-assisted sensing. The prepared platform aimed to create an adaptable tool that competes with traditional nanoparticle-based assays employing gold and silver. Analytical characterization and application of the testing platform showed high sensitivity (10 times better than gold nanoparticles), stability, fast turnaround, and reproducibility. The potential and possibilities demonstrated by the current platform could be observed in its adaptability for different markers and pathologies. In addition, smartphone-assisted sensing emphasizes the ability to use the tool at home by common peoples which can lower the burden on the healthcare facilities and reach more underdeveloped regions.

Dye-Loaded Polymersome-Based Lateral Flow Assay: Rational Design of a COVID-19 Testing Platform by Repurposing SARS-CoV-2 Antibody Cocktail and Antigens Obtained from Positive Human Samples.

The global pandemic of COVID-19 continues to be an important threat, especially with the fast transmission rate observed after the discovery of novel mutations. In this perspective, prompt diagnosis requires massive economical and human resources to mitigate the disease. The current study proposes a rational design of a colorimetric lateral flow immunoassay (LFA) based on the repurposing of human samples to produce COVID-19-specific antigens and antibodies in combination with a novel dye-loaded polymersome for naked-eye detection. A group of 121 human samples (61 serums and 60 nasal swabs) were obtained and analyzed by RT-PCR and ELISA. Pooled samples were used to purify antibodies using affinity chromatography, while antigens were purified via magnetic nanoparticles-based affinity. The purified proteins were confirmed for their specificity to COVID-19 via commercial LFA, ELISA, and electrochemical tests in addition to sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis. Polymersomes were prepared using methoxy polyethylene glycol-b-polycaprolactone (mPEG-b-PCL) diblock copolymers and loaded with a Coomassie Blue dye. The polymersomes were then functionalized with the purified antibodies and applied for the preparation of two types of LFA (antigen test and antibody test). Overall, the proposed diagnostic tests demonstrated 93 and 92.2% sensitivity for antigen and antibody tests, respectively. The repeatability (92-94%) and reproducibility (96-98%) of the tests highlight the potential of the proposed LFA. The LFA test was also analyzed for stability, and after 4 weeks, 91-97% correct diagnosis was observed. The current LFA platform is a valuable assay that has great economical and analytical potential for widespread applications.