Publications by authors named "Katerina Tsioka"

Article Synopsis
  • Clostridioides difficile infection (CDI) is a major cause of diarrhea in hospitalized patients, and this study focused on its incidence and epidemiology in a rehabilitation center in Thessaloniki, Greece, following the COVID-19 pandemic.
  • Conducted from January to December 2023, the retrospective observational study included patients of all ages with diarrhea, where CDI was confirmed and further analyzed through specific laboratory tests including PCR ribotyping.
  • The study found an annual CDI incidence of 27.1% with a decreasing trend over the year, a 5% mortality rate, and identified the dominant C. difficile strain as PCR ribotype 181, highlighting its prevalence and recurrence rates in the post-pandemic setting.
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ticks are vectors of a plethora of pathogens. The purpose of this study was to screen 398 ticks for a variety of pathogens. Following the pooling, homogenization, and extraction of total nucleic acids, a real-time PCR was applied for the detection of a panel of tick-borne pathogens, while additional conventional PCRs combined with Sanger sequencing were applied for the detection of viruses and typing of and species.

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Background: West Nile virus (WNV) outbreaks in birds, humans, and livestock have occurred in multiple areas in Europe and have had a significant impact on animal and human health. The patterns of emergence and spread of WNV in Europe are very different from those in the US and understanding these are important for guiding preparedness activities.

Methods: We mapped the evolution and spread history of WNV in Europe by incorporating viral genome sequences and epidemiological data into phylodynamic models.

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Since 2010, the West Nile virus (WNV) has been established in Greece. We describe the epidemiology of diagnosed human WNV infections in Greece with a focus on the 2022 season. During the transmission period, clinicians were sending samples from suspected cases for testing.

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Article Synopsis
  • Greece was significantly impacted by the West Nile virus (WNV) in 2022, particularly in Central Macedonia, which accounted for 81.5% of reported human cases.
  • A study collected over 30,000 Culex pipiens mosquitoes from the region, testing 690 pools for WNV, and found a 5.9% infection rate with variations across different areas and months.
  • The WNV detected belonged to the Central European subclade of lineage 2, showing slight genetic differences from the strain identified in Greece in 2010, highlighting the importance of mosquito monitoring for early virus detection and understanding its evolution.
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Introduction: Methicillin-resistant Staphylococcus aureus (MRSA) causes severe community and hospital acquired infections. Identification of staphylococcal cassette chromosome mec (SCCmec), multilocus-sequence typing, and sequencing of S. aureus protein A (spa) gene are used for MRSA typing.

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Article Synopsis
  • Since 2010, the West Nile virus (WNV) has been causing annual outbreaks in Greece, particularly affecting human health from May to October.
  • Between 2019 and 2021, over 51,000 Culex pipiens mosquitoes were collected in Central Macedonia, with 5% testing positive for WNV, showing varying infection rates across different regions and years.
  • Whole genome sequencing of 16 virus strains revealed that the WNV lineage 2, introduced in 2019, continued to circulate, providing important data for public health strategies and mosquito control efforts.
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During the 2020 West Nile virus (WNV) transmission season, Greece was the most affected EU Member State. More than one third of human cases occurred in Serres regional unit in northern Greece, which is characterized by the presence of a major wetland (Kerkini lake and Strimon river). A total of 2809 Culex pipiens mosquitoes collected in Serres were grouped into 70 pools and tested for WNV.

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Metagenomic next-generation sequencing (mNGS) is an untargeted technique for determination of microbial DNA/RNA sequences in a variety of sample types from patients with infectious syndromes. mNGS is still in its early stages of broader translation into clinical applications. To further support the development, implementation, optimization and standardization of mNGS procedures for virus diagnostics, the European Society for Clinical Virology (ESCV) Network on Next-Generation Sequencing (ENNGS) has been established.

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Bacterial carbapenem resistance, especially when mediated by transferable carbapenemases, is of important public health concern. An increased number of metallo-β-lactamase (MBL)-producing Klebsiella pneumoniae strains isolated in a tertiary hospital in Thessaloniki, Greece, called for further genetic investigation.The study included 29 non-repetitive carbapenem resistant K.

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Tick-borne bacteria pose a significant threat to human and veterinary public health. Greece is a Mediterranean country with rich tick fauna and the most commonly detected tick-borne bacterial pathogens are members of the and species. The variable V2-V4 and V6-V9 regions of 16S rRNA gene of seven ticks belonging to four genera representative in Greece () were analysed using multiple primer pairs by next generation sequencing (NGS).

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West Nile virus is a flavivirus transmitted to humans mainly by mosquito bites. Outbreaks are observed in several European countries, and Greece is one of the most affected countries during the recent years. Thessaly was one of the most affected regions in Greece in 2019.

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Article Synopsis
  • * West Nile virus (WNV) was found in 10 out of 229 mosquito pools, with a minimum infection rate of 0.57, particularly high in Thessaloniki where human cases were reported.
  • * The detection of WNV in mosquitoes occurred two weeks before the first human case, indicating that monitoring mosquito populations could help detect and prevent outbreaks.
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In order to gain an insight into the genetic relatedness of the Dobrava-Belgrade virus (DOBV) in Greece, a phylogenetic analysis was performed based on all currently available DOBV sequences obtained from hospitalized cases with hemorrhagic fever with renal syndrome (HFRS). Most cases occurred in northwestern and north central part of the country. Two sequence datasets consisted of 41 S and 12 M partial DOBV RNA segment sequences were analyzed.

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Crimean-Congo hemorrhagic fever virus (CCHFV) was isolated from a pool of two adult Rhipicephalus bursa ticks removed from a goat in 2015 in Greece. The strain clusters into lineage Europe 2 representing the second available whole-genome sequenced isolate of this lineage. CCHFV IgG antibodies were detected in 8 of 19 goats of the farm.

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Crimean-Congo hemorrhagic fever virus (CCHFV) is transmitted to humans mainly through the bite of infected ticks. In Greece, only one clinical case has been observed, in 2008, but the seroprevalence in humans is relatively high (4.2%).

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Albania is a Balkan country endemic for Crimean-Congo hemorrhagic fever (CCHF). It was shown previously that CCHF virus (CCHFV) sequences from Albanian patients cluster into Europe 1 clade. Aim of the present study was to test for CCHFV ticks collected in several regions of Albania, and to determine the genetic lineage(s) of the CCHFV strains in relation with their geographic distribution.

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Crimean-Congo hemorrhagic fever virus (CCHFV) is transmitted to humans by bite of infected ticks or by direct contact with blood or tissues of viremic patients or animals. It causes to humans a severe disease with fatality up to 30%. The current knowledge about the vector-host-CCHFV interactions is very limited due to the high-level containment required for CCHFV studies.

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During the last decade the number of novel tick-borne phleboviruses has increased rapidly, especially after the identification of severe fever with thrombocytopenia syndrome and Heartland viruses which can cause severe disease in humans. A novel virus, Antigone virus was recently detected in ticks collected from the mainland of Greece. The aim of the present study was to investigate the presence of tick-borne phleboviruses in an island in Greece.

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Ticks collected from goats in northern Greece were tested for the presence of tick-borne bacteria. Among adult ticks, 37 (57.8%) were Rhipicephalus bursa, 11 (17.

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Since 2009, when severe fever with thrombocytopenia syndrome virus and Heartland virus have been identified and associated with disease in humans, the interest on tick-borne phleboviruses is increasing rapidly. The aim of the present study was to investigate the presence of tick-borne phleboviruses in Greece and compare them with respective ones detected worldwide. Ticks collected from goats and sheep in 60 sites of 13 regional units of Greece were grouped in pools (1-3 ticks per pool) and tested for the presence of phleboviral RNA.

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Article Synopsis
  • West Nile virus (WNV) was detected in Culex mosquitoes in central Macedonia, Greece, starting in 2010, raising concerns about human cases correlating with mosquito infection.
  • In 2013, researchers collected over 25,000 mosquitoes and found that 4.4% of them tested positive for flavivirus, with WNV lineage 2 present in 3.1% of the pools.
  • The results indicate that WNV is now established in Greece, and early detection in mosquitoes can serve as a warning system for potential human infections.
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Ticks were collected from various regions of northern Greece and tested for the presence of Crimean-Congo hemorrhagic fever virus (CCHFV) RNA. Human and animal sera were collected in the regions where CCHFV-positive ticks were detected, and they were tested for the presence of IgG antibodies against the virus. A CCHFV strain was detected in Rhipicephalus bursa ticks collected from sheep in Kastoria regional unit, differing by 9.

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Following an outbreak of West Nile virus (WNV) infections in Greece during summer/autumn 2010, a study was conducted to investigate the patterns of WNV IgG reactivity in 255 patients with respect to the day of illness and the type of clinical syndrome. IgG antibodies were detectable after a mean of 8.1 ± 4.

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