Changes in hospitals’ daily practice due to COVID-19 pandemic may have an impact on antimicrobial resistance (AMR). We aimed to assess this possible impact as captured by the Greek Electronic System for the Surveillance of Antimicrobial Resistance (WHONET-Greece). Routine susceptibility data of 17,837 Gram-negative and Gram-positive bacterial isolates from blood and respiratory specimens of hospitalized patients in nine COVID-19 tertiary hospitals were used in order to identify potential differences in AMR trends in the last three years, divided into two periods, January 2018–March 2020 and April 2020–March 2021. Interrupted time-series analysis was used to evaluate differences in the trends of non-susceptibility before and after the changes due to COVID-19. We found significant differences in the slope of non-susceptibility trends of Acinetobacter baumannii blood and respiratory isolates to amikacin, tigecycline and colistin; of Klebsiella pneumoniae blood and respiratory isolates to meropenem and tigecycline; and of Pseudomonas aeruginosa respiratory isolates to imipenem, meropenem and levofloxacin. Additionally, we found significant differences in the slope of non-susceptibility trends of Staphylococcus aureus isolates to oxacillin and of Enterococcus faecium isolates to glycopeptides. Assessing in this early stage, through surveillance of routine laboratory data, the way a new global threat like COVID-19 could affect an already ongoing pandemic like AMR provides useful information for prompt action.

Monophasic Salmonella typhimurium is of increasing importance worldwide. Here we present the available data regarding monophasic S. typhimurium from 2007 to 2019 in Greece, in order to assess its public health impact. Surveillance data, data on antimicrobial resistance, molecular typing by pulsed-field gel electrophoresis (PFGE), and results of the investigation of monophasic S. typhimurium outbreaks were analyzed. Overall, 403 cases were identified; 329 (81.6%) sporadic and 74 (18.4%) related to two community outbreaks in 2017. A total of 305 isolates from sporadic cases tested for antimicrobial resistance revealed resistance to ampicillin, streptomycin, sulphamethoxazole, and tetracycline (41.3%). Some 23.3% were further resistant to trimethoprim and 5.2% were also resistant to chloramphenicol. Outbreak 1 in 2017 with 37 identified cases was attributed to the consumption of raw milk from a vending machine and isolates were resistant to ampicillin, streptomycin, sulphamethoxazole, tetracycline, and trimethoprim. Outbreak 2 also with 37 cases was attributed to the consumption of pork and isolates were resistant to the five above mentioned antibiotics plus chloramphenicol. The number of human monophasic S. typhimurium isolates is low; however, since 2009, it has been among the five most frequently identified serotypes in Greece. Investigation of the outbreaks revealed that other vehicles apart from pork may be implicated in the occurrence of outbreaks.

Here, we report on the emergence and spread of multidrug-resistant NDM-1-producing P. aeruginosa isolates from patients hospitalized in the Attica region, Greece, in 2022 to provide data on their resistome, their virulome, the genetic environment of bla_NDM-1, and their molecular epidemiology. A total of 17 carbapenem-resistant P. aeruginosa isolates identified as NDM-producers by immunochromatography at the hospital level were sent to the Central Public Health Laboratory, in the frame of the laboratory surveillance of carbapenem-resistant pathogens, for further characterization. The initial screening for genetic AMR determinants was carried out by PCR and the MDR Direct Flow Chip assay. Typing was performed by MLST and DLST, the latter in a subset of isolates. Further analysis was performed by whole-genome sequencing (WGS) of six isolates from both hospitals to analyze their entire genomes and elucidate their genetic relatedness. All isolates were allocated to international high-risk clones, sixteen to ST773 and one to ST308. Five ST773 and the sole ST308 isolate were found to harbor the bla_NDM-1 gene, along with various other ARGs integrated into their chromosomes, as well as with a wide variety of virulence genes. The bla_NDM-1 gene was located in the integrative and conjugative elements ICE6600-like and ICE_Tn43716385 in ST773 and ST308 isolates, respectively. Single-nucleotide polymorphism analysis of the five ST773 isolates indicated their clonal spread in both hospitals. These results suggested that two different molecular events contributed to the emergence of NDM-1-producing P. aeruginosa isolates in Athenian hospitals, highlighting the need for ongoing surveillance.

In May 2022, for the first time, multiple cases of mpox were reported in several non-endemic countries. The first ever case of the disease in Greece was confirmed on 8 June 2022, and a total of 88 cases were reported in the country until the end of April 2023. A multidisciplinary response team was established by the Greek National Public Health Organization (EODY) to monitor and manage the situation. EODY’s emergency response focused on enhanced surveillance, laboratory testing, contact tracing, medical countermeasures, and the education of health care providers and the public. Even though management of cases was considered successful and the risk from the disease was downgraded, sporadic cases continue to occur. Here, we provide epidemiological and laboratory features of the reported cases to depict the course of the disease notification rate. Our results suggest that measures for raising awareness as well as vaccination of high-risk groups of the population should be continued.

Background: European countries have included healthcare workers (HCWs) among priority groups for COVID-19 vaccination. We established a multi-country hospital network to measure the SARS-CoV-2 incidence and effectiveness of COVID-19 vaccines among HCWs against laboratory-confirmed SARS-CoV-2 infection. Methods: HCWs from 19 hospitals in 10 countries participated in a dynamic prospective cohort study, providing samples for SARS-CoV-2 testing at enrolment and during weekly/fortnightly follow-up. We measured the incidence during pre-Delta (2 May–6 September 2021), Delta (7 September–14 December 2021), and Omicron (15 December 2021–2 May 2023) waves. Using Cox regression, we measured the relative vaccine effectiveness (rVE) of the first COVID-19 booster dose versus primary course alone during Delta and Omicron waves. Results: We included a total of 3015 HCWs. Participants were mostly female (2306; 79%), with a clinical role (2047; 68%), and had a median age of 44 years. The overall incidence of SARS-CoV-2 infection was 3.01/10,000 person-days during pre-Delta, 4.21/10,000 during Delta, and 23.20/10,000 during Omicron waves. rVE was 59% (95% CI: −25; 86) during Delta and 22% (1; 39) during Omicron waves. rVE was 51% (30; 65) 7–90 days after the first booster dose during the Omicron wave. Conclusions: The incidence of SARS-CoV-2 infection among HCWs was higher during the Omicron circulation period. The first COVID-19 vaccine booster provided additional protection against SARS-CoV-2 infection compared to primary course vaccination when recently vaccinated <90 days. This multi-country HCW cohort study addressing infection as the main outcome is crucial for informing public health interventions for HCWs.

Antimicrobial resistance is a significant global health challenge, with Klebsiella pneumoniae being one of the most common antibiotic-resistant pathogens. This study provides an in-depth analysis of the prevalence and resistance patterns of antibiotic-resistant Klebsiella pneumoniae in the General Hospital of Corfu, Greece, between 2019 and 2022, with the aim of understanding the potential impact of the COVID-19 pandemic on the epidemiology of this bacterium. Utilizing a retrospective epidemiological approach, this study analyzed 212 isolates obtained from the hospital’s Microbiology Department. These isolates were subjected to genotypic and phenotypic identification, with resistance genes (bla-KPC, bla-NDM, bla-VIM, bla-OXA-48, and mcr-1) and antibiotic resistance patterns as the primary focus. The results revealed a significant shift in resistance gene prevalence, with a notable increase in bla-KPC from 16.67% in 2021 to 58.46% in 2022, and a decrease in bla-NDM from 81.48% in 2021 to 38.46% in 2022. In terms of antibiotic resistance patterns, there was a consistent increase in resistance to amikacin and a significant decrease in resistance to ceftazidime/avibactam. These findings underscore the dynamic nature of carbapenem-resistant Klebsiella pneumoniae (CRKP) resistance and highlight the need for ongoing surveillance and adaptive therapeutic strategies in the face of evolving resistance patterns.