Ioanna Gkeka

Aristotle University of Thessaloniki

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Lemonia Skoura

AHEPA University Hospital

Georgios Meletis

AHEPA University Hospital

Areti Tychala

AHEPA University Hospital

Efthymia Protonotariou

AHEPA University Hospital

Barbara Fyntanidou

AHEPA University Hospital

Paraskevi Mantzana

AHEPA University Hospital

Kali Makedou

Aristotle University of Thessaloniki

Sofia Gkarmiri

Aristotle University of Thessaloniki

Angeliki Kassomenaki

AHEPA University Hospital

Anna Papa

Aristotle University of Thessaloniki

Cooperative Institutions

Aristotle University of Thessaloniki

AHEPA University Hospital

National and Kapodistrian University of Athens

University of Thessaly

Hippocration General Hospital

Ippokrateio General Hospital of Thessaloniki

Papageorgiou General Hospital

University of Ioannina

University of Cyprus

Alexander Technological Educational Institute of Thessaloniki

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Antibody response after two doses of the BNT162b2 vaccine among healthcare workers of a Greek Covid 19 referral hospital: A prospective cohort study

Heliyon (2022)

Areti Tychala Eleni Sidiropoulou Sofia Dionysopoulou Ioanna Gkeka Georgios Meletis

The global vaccination against SARS-CoV-2 has highlighted the need of assessing vaccines' immunogenicity against COVID-19. To evaluate humoral immunity induced by the BNT162b2 vaccine, we enrolled health care workers at AHEPA University Hospital of Thessaloniki, Greece to measure Anti-S SARS-CoV-2, anti-RBD SARS-CoV-2 and neutralizing antibodies. A total of 955 individuals with a median age of 50 years, were included in the study. Median values of antibodies were 1947.27 BAU/mL (Abbott SARS-CoV-2 IgG II Quant), 2064.98 BAU/mL (MAGLUMI SARS-CoV-2 S-RBD IgG) and 2464.63 IU/mL (MAGLUMI SARS-CoV-2 Neutralizing Antibodies). Individuals previously infected had greater antibody responses than infection naive ones and a 7-fold higher neutralizing antibodies titre. Antibodies degreased by age but not sex. Spearman's correlation coefficient among the three assays ranged from 0.903 to 0.969. The BNT162b2 vaccine was highly immunogenic in our cohort. Further research is needed to evaluate the vaccine's immunogenicity through time as well as in different populations.

10.1016/j.heliyon.2022.e09438

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Evaluation of the Advanta Dx SARS-CoV-2 RT-PCR Assay, a High-Throughput Extraction-Free Diagnostic Test for the Detection of SARS-CoV-2 in Saliva: A Diagnostic Accuracy Study

Diagnostics (2021)

Sofia Balaska Dimitrios Pilalas Anna Takardaki Paraskevoula Koutra Eleftheria Parasidou

Nasopharyngeal swab specimen (NPS) molecular testing is considered the gold standard for SARS-CoV-2 detection. However, saliva is an attractive, noninvasive specimen alternative. The aim of the study was to evaluate the diagnostic accuracy of Advanta Dx SARS-CoV-2 RT-PCR saliva-based assay against paired NPS tested with either NeumoDxTM SARS-CoV-2 assay or Abbott Real Time SARS-CoV-2 assay as the reference method. We prospectively evaluated the method in two settings: a diagnostic outpatient and a healthcare worker screening convenience sample, collected in November-December 2020. SARS-CoV-2 was detected in 27.7% (61/220) of diagnostic samples and in 5% (10/200) of screening samples. Overall, saliva test in diagnostic samples had a sensitivity of 88.5% (77.8-95.3%) and specificity of 98.1% (94.6-99.6%); in screening samples, the sensitivity was 90% (55.5-99.7%) and specificity 100% (98.1-100%). Our data suggests that the Fluidigm Advanta Dx RT-PCR saliva-based assay may be a reliable diagnostic tool for COVID-19 diagnosis in symptomatic individuals and screening asymptomatic healthcare workers.

Gold standard (test)

Roche Diagnostics

2019-20 coronavirus outbreak

10.3390/diagnostics11101766

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Citations (7)

Negative Predictive Value of the Rapid Test Ag 2019-nCoV During the Predominance of Omicron over the Delta Variant and Implications in the Emergency Department

SN Comprehensive Clinical Medicine (2022)

Barbara Fyntanidou Georgios Meletis Sofia Gkarmiri Ioanna Gkeka Areti Tychala

Abstract The high prevalence of asymptomatic patients infected with SARS-CoV-2 during the pandemic peaks and the common occurrence of in-hospital transmission urges the need for SARS-CoV-2 testing before admission of all patients with non-COVID-related symptoms. RT-PCR testing however is costly, time-consuming, and increases the length of stay in the emergency department. For the aforementioned reasons, we propose that the admission of non-suspected COVID-19 patients to the appropriate department should be based on the sole use of the rapid test result. In order to assess the safety of this suggestion, we assessed the negative predictive value of our rapid antigen tests that was calculated at 96.38%. This value was considered acceptable and the proposed strategy was applied in our hospital improving the overall turnaround times. However, since various rapid tests may perform differently, we propose that hospitals assess their own methodologies before implementing our proposal.

2019-20 coronavirus outbreak

Value (mathematics)

10.1007/s42399-022-01294-y

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Clinical Performance Evaluation of the NeuMoDx Flu A-B/RSV/SARS-CoV-2 Vantage Assay

Diagnostics (2022)

Georgios Meletis Areti Tychala Ioanna Gkeka Athanasia Gkotzia Aikaterini Triantafyllou

SARS-CoV-2 infections may present with various symptoms that are similar to those of other respiratory diseases. For this reason, the need for simultaneous detection of at least RSV and influenza viruses together with SARS-CoV-2 was evident from the early stages of the pandemic. In the present study, we evaluated the clinical performance of the NeuMoDx™ Flu A-B/RSV/SARS-CoV-2 Vantage Assay against the conventional low-plex PCR utilized to detect influenza A-B, RSV, and SARS-CoV-2. There were 115 known positive clinical samples and 35 negative controls obtained from asymptomatic health-care workers included in the study; 25 samples were positive for influenza viruses, 46 for RSV, and 44 for SARS-CoV-2. The sensitivity, specificity, positive predictive value, and negative predictive value of the evaluated method for influenza and SARS-CoV-2 were 100%. The Spearman correlation coefficient was 0.586 (p < 0.05) for influenza and 0.893 (p < 0.05) for SARS-CoV-2. The sensitivity of the aforementioned assay for RSV was 93.47%; the specificity and the positive predictive value were 100%, and the negative predictive value was 92.10%, while the Spearman correlation coefficient was not applicable for the RSV. Overall, the assay under evaluation was shown to be a reliable alternative for the simultaneous detection of influenza viruses, RSV and SARS-CoV-2.

Positive predicative value

Pandemic

10.3390/diagnostics12123201

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Citations (1)

In Vitro Activity of Cefiderocol and Comparators against Multi-Drug Resistant Acinetobacter baumannii Isolates

Areti Tychala Efthymia Protonotariou Paraskevi Mantzana Georgios Meletis Ioanna Gkeka

Acinetobacter baumannii is an aerobic Gram-negative bacterium which causes facultative hospital infections and, in settings such as Greece, exhibits high resistance rates against most antimicrobial agents [...]

Acinetobacter baumannii

10.3390/eca2022-12741

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In vitro activity of eravacycline and cefoperazone/ sulbactam against extensively-drug resistant and pan-drug resistant Acinetobacter baumannii isolates from a tertiary hospital in Greece.

PubMed (2022)

Georgios Meletis Efthymia Protonotariou Ioanna Gkeka Angeliki Kassomenaki Paraskevi Mantzana

We evaluated the in vitro activity of eravacycline and cefoperazone/sulbactam against 42 XDR and 58 PDR Acinetobacter baumannii isolates from blood and bronchoalveolar infections. The minimum and maximum MICs for eravacycline were 0.125 and 4 mg/L, respectively. The MIC50 was 2 mg/L and the MIC90 was 3 mg/L. The minimum and maximum MICs for cefoperazone/sulbactam were 24 and >256 mg/L, respectively. The MIC50 and MIC90 were both >256 mg/L. These novel agents were not adequate for the treatment of A. baumannii infections in our hospital and we recommend that mi- crobiology laboratories perform their own evaluations before including them in clinical practice.

Acinetobacter baumannii

Cefoperazone

Sulbactam

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Citations (2)

Vitamin D and LL-37 in Serum and Saliva: Insights into Oral Immunity

Current Issues in Molecular Biology (2025)

Sotiria Davidopoulou Kali Makedou Areti Kourti Ioanna Gkeka Panagiotis Karakostas

(1) Background: In recent years, there has been a growing interest in understanding the innate immunity of the mouth, particularly the mechanisms through which vitamin D influences oral health. Researchers have increasingly focused on the association between vitamin D and the antimicrobial peptide LL-37 since the CAMP gene, responsible for encoding the LL-37 peptide, is a direct target of both vitamin D and its receptor (vitamin D receptor, VDR). This study aimed to explore the correlation between the 25-hydroxyvitamin D (25(OH)D) levels and the concentration of the LL-37 peptide in both serum and saliva. The objective was to compare the serum concentrations of 25(OH)D and ll-37 with those in saliva and to access the correlations between the two compounds. (2) Methods: Serum and whole saliva samples were collected from 72 healthy adults (mean age 28.68 ± 8.35). The levels of 25(OH)D and LL-37 were assessed in both the saliva and serum samples using commercially available enzyme-linked immunosorbent assay (ELISA) kits. (3) Results: The 25(OH)D levels in the serum (median 5.92 ng/mL, min–max 2.7–10.4 ng/mL) correlated with the LL-37 serum levels (62 ng/mL, min–max 18–378 ng/mL; Pearson’s r 0.328, p = 0.005). Additionally, the 25(OH)D levels in saliva (median 1.16 ng/mL, min–max 0.54–2.12 ng/mL) strongly correlated with the LL-37 salivary levels (median 44 ng/mL, min–max 6.5–205 ng/mL; Pearson’s r 0.667, p < 0.001). The 25(OH)D salivary levels demonstrated a robust correlation with the LL-37 salivary levels. (4) Conclusions: This discovery emphasizes the complex interplay between vitamin D and LL-37 and lay the groundwork for the further exploration of vitamin D’s role in oral immune function.

10.3390/cimb47020102

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Early initiation of the respiratory syncytial virus season in 2021–2022, Greece

Journal of Medical Virology (2022)

Styliani Pappa Katerina Haidopoulou Charalampos Zarras Eleni Theodorakou Eleni Papadimitriou

Abstract Respiratory syncytial virus (RSV) is the most common viral pathogen causing respiratory disease in the pediatric population. An unexpected sudden upsurge of RSV infections among children was observed in September 2021 in Greece. Forty‐one rhinopharyngeal samples from children under the age of 2 years with confirmed RSV bronchiolitis were tested to identify the genotype(s) of the RSV strain(s). The children were hospitalized during September−November 2021 in three tertiary hospitals in northern Greece. A one‐step RT‐PCR which amplifies a fragment of the second hypervariable region of the G protein gene was applied. PCR products were sequenced, and phylogenetic analysis was performed. Most (80.5%) RSV cases were typed as RSV‐A, with RSV‐B accounting for 19.5% of cases. RSV‐A and RSV‐B sequences clustered within the ON1 and BA genotypes, respectively. As the same genotypes were detected in cases observed during 2016–2018 in northern Greece, it was suggested that the early upsurge of infections was not related to the emergence of novel strain(s), but it was the result of the absence of immunity among children and their mothers due to the restriction measures taken during the COVID‐19 pandemic in the previous RSV season. Awareness is needed to diagnose even the out‐of‐season RSV infections, while molecular epidemiology plays a key role in monitoring the efficacy of currently available therapeutics and for those under development.

Molecular Epidemiology

10.1002/jmv.27671

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Citations (11)

Laboratory evaluation of the Abbott ID NOW rapid severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) amplification assay and its potential use in the emergency department

Infection Control and Hospital Epidemiology (2021)

Georgios Meletis Ioanna Gkeka Areti Tychala Barbara Fyntanidou Lydia Kouroudi

An abstract is not available for this content. As you have access to this content, full HTML content is provided on this page. A PDF of this content is also available in through the 'Save PDF' action button.

2019-20 coronavirus outbreak

Coronavirus

Betacoronavirus

Coronavirus Infections

Sars virus

10.1017/ice.2021.360

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Citations (2)

Evaluation of the QuantiFERON SARS-CoV-2 assay to assess cellular immunogenicity of the BNT162b2 mRNA COVID-19 vaccine in individuals with low and high humoral response

Human Vaccines & Immunotherapeutics (2021)

Areti Tychala Georgios Meletis Eugenia Katsimpourlia Ioanna Gkeka Rodoula Dimitriadou

Vaccines against SARS-CoV-2 are known to be less immunogenic for some individuals, whereas others present notably high levels of antibody production. We assessed the cellular response to BNT162b2 among individuals with low post-vaccination antibody levels as well as in a small group of individuals with high titers. Antibody levels were assessed by the Abbott SARS-CoV-2 IgG II Quant assay. The interferon-γ production of T-cells in response to SARS-CoV-2 antigens was determined using Qiagen's QuantiFERON SARS-CoV-2 ELISA test. Our results showed that participants with high antibody levels presented adequate cellular response in all studied cases, whereas those with low antibody levels generally showed limited to almost absent cellular response five months post vaccination.

QuantiFERON

Antibody response

Antibody titer

10.1080/21645515.2021.1991710

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Citations (18)