Aikaterini Michelaki

Dr. Aikaterini Michelaki

orcid

Research Focus & Metrics

Academic Career Length

2Years (2025-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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26 February 2025 in Antibiotics
Verified
Journal Article
Open access
PDF file
VKVasiliki Koumaki
Vasiliki Koumaki
EVEleni Voudanta
Eleni Voudanta
AMAikaterini Michelaki
Aikaterini Michelaki
MOMaria Orfanidou
Maria Orfanidou
EVEleni Vagiakou
Eleni Vagiakou
Athanasios TsakrisAthanasios Tsakris
Athanasios Tsakris
Background: Carbapenemase-producing Enterobacterales (CPEs) represent a significant global health threat, particularly in the context of nosocomial infections. The current study constitutes a retrospective epidemiological survey that aimed to provide updated data on the prevalence and characteristics of carbapenemases among carbapenem-resistant Enterobacterales (CREs) in a Greek tertiary hospital in Athens during and after the COVID-19 pandemic. Results: A total of 2021 non-duplicate CPE clinical isolates were detected. A significant increase in the number of carbapenemase-positive Enterobacterales was revealed during the study period (p < 0.05). KPC remained the predominant carbapenemase type through all four years of the survey, representing 40.7%, 39.9%, 53.5%, and 45.7% of the CPE isolates, respectively. However, a rapid transition from VIM to NDM metal-β-lactamase types was revealed, changing the epidemiological image of carbapenemases in the hospital setting. Notably, among the CPEs, antimicrobial resistance rates were significantly raised in the post-COVID-19 period (2022 and 2023) compared to the first study year (2020) for almost all the tested antibiotics, including those characterized as last-resort antibiotics. Methods: CREs were identified and subjected to screening for the five most prevalent carbapenemase genes [Klebsiella pneumoniae carbapenemase (KPC), Verona integron-borne metallo-β-lactamase (VIM), New Delhi metallo-β-lactamase (NDM), imipenemase (IMP), and oxacillin-hydrolyzing (OXA-48)] using a lateral flow immunoassay, and the CREs recovered from blood cultures were analyzed using a FilmArray system. Their clinical and epidemiological characteristics, as well as their antimicrobial susceptibility profiles, were also subjected to analysis Conclusions: Given this alarming situation, which is exacerbated by the limited treatment options, the development of new, effective antimicrobial agents is needed. The continued monitoring of the changing epidemiology of carbapenemases is also imperative in order to undertake rational public health interventions.

11 January 2025 in Journal of Clinical Medicine
Verified
Journal Article
Open access
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PTPanagiotis Toumasis
Panagiotis Toumasis
Georgia VrioniGeorgia Vrioni
Georgia Vrioni
IGIoanna Gardeli
Ioanna Gardeli
AMAikaterini Michelaki
Aikaterini Michelaki
MEMaria Exindari
Maria Exindari
MOMaria Orfanidou
Maria Orfanidou
Background: Macrophomina phaseolina is an important phytopathogenic fungus affecting over 500 plant species worldwide. However, this fungus rarely causes disease in humans. Methods: We reported the first case of endophthalmitis due to M. phaseolina, describing microbiological diagnostic approaches. Also, we performed a systematic review of human infections by this plant pathogen in literature. We searched PubMed, Scopus, and Web of Science databases from inception to 31 December 2024. Results: Our case involved a male patient who presented with photophobia and pain in his right eye. His recent medical history revealed a superficial corneal injury caused by a metal burr three months prior, managed unsuccessfully by topical treatment and subsequent conjunctival flap surgery two months later. Ophthalmological and microbiological investigations, including microscopic examination, cultures, and DNA sequencing of ocular specimens, revealed M. phaseolina endophthalmitis. Despite intravenous and intravitreal antifungal therapy, the patient’s condition continued to worsen, eventually leading to enucleation. Regarding the literature review, we identified 12 additional cases of M. phaseolina human infections previously reported in literature. Overall, M. phaseolina was primarily associated with ocular infections (76.9% of cases), followed by skin infections and combined skin–joint infections. The majority of patients with M. phaseolina infection (63.6%) had no known immunosuppressive factors. Clinical outcomes were unfavorable in 46.15% of cases. Conclusions: M. phaseolina is an emerging cause of human infections, even in immunocompetent hosts, with a predilection for ocular infections. Further research is warranted to elucidate the pathogenesis of fungal infections caused by plant pathogens in humans.

5 September 2025 in Antibiotics
Verified
Journal Article
Open access
PDF file
VKVasiliki Koumaki
Vasiliki Koumaki
EVEleni Voudanta
Eleni Voudanta
AMAikaterini Michelaki
Aikaterini Michelaki
MOMaria Orfanidou
Maria Orfanidou
EVEleni Vagiakou
Eleni Vagiakou
Athanasios TsakrisAthanasios Tsakris
Athanasios Tsakris
Background: Infections caused by carbapenemase-producing Pseudomonas aeruginosa (CPPA) isolates have become a worldwide clinical challenge for clinicians due to the limited treatment options. This study provides epidemiological data on CPPA clinical isolates recovered from one of the largest tertiary care hospitals in Athens, Greece, serving a diverse patient population during and after the COVID-19 pandemic. Materials and Methods: The study included all consecutive single-patient CPPA clinical isolates identified from January 2020 to December 2023 in the clinical laboratory. Identification and antimicrobial susceptibility testing were performed using the VITEK-2 automated system. A lateral flow immunoassay and the FilmArray system for blood cultures only were used for the detection of the five most prevalent carbapenemases. Their epidemiological and antimicrobial susceptibility trends were retrospectively analyzed. Results: During the study period, a total of 628 single-patient CPPA were identified among 902 carbapenem-resistant P. aeruginosa clinical isolates. An increasing number of CPPA was revealed during the survey, especially in the post-COVID period (rising from n = 102 in 2020, n = 105 in 2021, and n = 123 in 2022 to n = 298 in 2023; p < 0.05). Regarding the type of carbapenemase, VIM metallo-beta-lactamase was the only carbapenemase identified during the first two years of the study (2020 to 2021). In 2022, VIM- and NDM-producing isolates split almost evenly at proportions of 57% and 43%, respectively. In 2023, NDM-producing isolates seem to have surpassed VIM producers with rates of 54.4% and 45.6%, respectively. As far as antimicrobial resistance profiles, high rates of resistance were observed for most of the antipseudomonal drugs, exceeding 90% across all study years, with little significant variation. However, aztreonam exhibited moderate activity and colistin exhibited excellent activity, remaining the most viable drugs in this setting. Conclusions: Following the COVID-19 pandemic, an increase in CPPA pathogens was identified, while an epidemiological shift was also observed, with the carbapenemase NDM dominating over VIM since 2023. Continuous surveillance is required to track resistance patterns and guide empirical therapy. In this context, new antimicrobials and antimicrobial combinations are also urgently needed.

25 July 2025 in Antibiotics
Verified
Journal Article
Open access
AMAngeliki Mavroidi
Angeliki Mavroidi
EFElisavet Froukala
Elisavet Froukala
NSNikolaos Spanakis
Nikolaos Spanakis
AMAikaterini Michelaki
Aikaterini Michelaki
MOMaria Orfanidou
Maria Orfanidou
Athanasios TsakrisAthanasios Tsakris
Athanasios Tsakris
Background/Objectives: Among Enterobacterales, OXA-48-like-producing Proteus mirabilis strains have been scarcely detected. Herein, we characterized a blaOXA-48-harbouring P. mirabilis strain recovered from Greece (Pm GR-1), while phylogenomics and comparative genomics analyses with previously published blaOXA-48 carriers were also assessed. Methods: Characterization of Pm GR-1 was performed by the Vitek® Compact and Mass Spectrometry systems, antimicrobial susceptibility testing, detection of beta-lactamases, multilocus-sequence typing (MLST), and whole-genome sequencing (WGS). In silico prediction of mobile genetic elements (MGEs), genomic islands (GIs), antimicrobial resistance genes (ARGs) and virulence factors (VFs), and phylogenetic, core-genome SNP and comparative genomics analyses were executed using bioinformatic tools. Results: Pm GR-1 was isolated from a urine sample of an outpatient in a Greek hospital. It exhibited a multidrug-resistant phenotype, being susceptible only to amikacin and ceftazidime/avibactam. It co-carried several beta-lactamase genes on the chromosome (blaOXA-48, blaCTX-M-14, blaTEM-1) and a plasmid (blaTEM-2) and several other ARGs, but also mutations associated with quinolone resistance in the DNA gyrase and topoisomerase IV subunits. It belonged to the international clone ST135 that has also been detected among OXA-48-producing P. mirabilis strains from Germany and the USA. Pm GR-1 was genetically related to those from Germany, sharing highly similar MGEs, GIs, ARGs and VFs, including the chromosomal blaOXA-48 genetic structure, the O-antigen locus, the flagella locus, the MR/P fimbriae operon, and the urease gene cluster. Conclusions: To our knowledge, this is the first report from Greece of a blaOXA-48-possessing P. mirabilis strain. The emergence of blaOXA-48 among P. mirabilis strains of the international clone ST135 in different geographical regions is worrying. Close monitoring of these strains is required in One Health settings.