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ABSTRACT: Objectives: Streptococcus pyogenes causes superficial infections but can also cause deep-seated infections and toxin-mediated diseases. In the present study, phylogenetic and in silico prediction analyses were performed on an antimicrobial resistant M1UK S. pyogenes strain causing severe clinical manifestations during the current surge of invasive group A Streptococcus (iGAS) disease. Methods: A 40-year-old patient was admitted to the hospital with fever, chest pain and fatigue. Based on the clinical and laboratory findings, a diagnosis of sepsis with disseminated intravascular coagulation, community-acquired pneumonia, pleural empyema and streptococcal toxic shock syndrome was made. Microbial identification was performed by multiplex PCR and conventional culturing. Furthermore, antimicrobial susceptibility testing, whole genome sequencing, phylogenomic analysis and in silico prediction analysis of antimicrobial resistance genes and virulence factors were performed. Results: S. pyogenes isolates were detected in pleural fluid and sputum of the patient. Both isolates belonged to the M1UK lineage of the emm1/ST28 clone, being closely related with an M1UK GAS strain from Australia. They exhibited resistance to erythromycin and clindamycin and susceptibility-increased exposure to levofloxacin and carried genes encoding for protein homologues of antibiotic efflux pumps. Moreover, several virulence factors, and a previously described single-nucleotide polymorphism in the 5′ transcriptional leader sequence of the ssrA gene, which enhances expression of SpeA, were detected. Conclusions: The present antimicrobial-resistant M1UK S. pyogenes strain represents the first report of this emerging lineage associated with such manifestations of iGAS disease.

Abstract Our study aimed to estimate the prevalence of total free flap failure following free flap reconstruction for mandibular osteoradionecrosis (mORN) and assess the impact of potential moderators on this outcome. A comprehensive systematic literature search was independently conducted by two reviewers using the Medline, Scopus, Web of Science and Cochrane Library databases. Quality assessment of the selected studies was performed, and prevalence estimates with 95% confidence intervals (CI) were calculated. Outlier and influential analyses were conducted, and meta-regression analyses was employed to investigate the effects of continuous variables on the estimated prevalence. Ultimately, forty-six eligible studies (involving 1292 participants and 1344 free flaps) were included in our meta-analysis. The findings of our study revealed a prevalence of 3.1% (95% CI 1.3–5.4%) for total free flap failure after reconstruction for mORN. No study was identified as critically influential, and meta-regression analysis did not pinpoint any potential sources of heterogeneity. These findings provide valuable insights for researchers and serve as a foundation for future investigations into the management of mandibular osteoradionecrosis and the prevention of free flap failure in this context.

Olfactory dysfunction (OD) is not uncommon following viral infection. Herein, we explore the interplay of host genetics with viral correlates in coronavirus disease 2019 (COVID-19)- and long COVID-related OD, and its diagnosis and treatment that remain challenging. Two genes associated with olfaction, UGT2A1 and UGT2A2, appear to be involved in COVID-19-related anosmia, a hallmark symptom of acute infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), particularly in the early stages of the pandemic. SARS-CoV-2 infects olfactory support cells, sustentacular and Bowman gland cells, that surround olfactory sensory neurons (OSNs) in the olfactory epithelium (OE) where the initial step of odor detection takes place. Anosmia primarily arises from the infection of support cells of the OE, followed by the deciliation and disruption of OE integrity, typically without OSN infection. Through the projected axons of OSNs, the virus could theoretically reach the olfactory bulb and brain, but current evidence points against this route. Intriguingly, SARS-CoV-2 infection of support cells leads to profound alterations in the nuclear architecture of OSNs, leading to the downregulation of odorant receptor-related genes, e.g., of Adcy3. Viral factors associated with the development of OD include spike protein aminoacidic changes, e.g., D614G, the first substitution that was selected early during SARS-CoV-2 evolution. More recent variants of the Omicron family are less likely to cause OD compared to Delta or Alpha, although OD has been associated with a milder disease course. OD is one of the most prevalent post-acute neurologic symptoms of SARS-CoV-2 infection. The tens of millions of people worldwide who have lingering problems with OD wait eagerly for effective new treatments that will restore their sense of smell which adds value to their quality of life.

The continued rise in antimicrobial resistance poses a serious threat to public health worldwide. The use of phages that can have bactericidal activity without disrupting the normal flora represents a promising alternative treatment method. This practice has been successfully applied for decades, mainly in Eastern Europe, and has recently been used as an emergency therapy for compassionate care in the United States. Here, we provide a comprehensive review of the pre-clinical and clinical applications of phage therapy concerning three major Gram-negative pathogens: Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii. The advantages and the challenges of expanding the usage of phages as an alternative or adjunctive treatment for antimicrobial-resistant bacterial infections are discussed. We emphasize the virologic complexities of using the highly adaptable phage populations as molecular tools, along with antibiotic chemical compounds, to effectively combat rapidly coevolving pathogenic bacteria in the host microenvironment. Pre-clinical studies, isolated clinical reports and a few randomized clinical trials have shown that bacteriophages can be effective in treating multidrug-resistant bacterial infections. The ability of some phages to revert the resistance against antibiotics, and possibly also against the human complement and other phages, appears to be a great advantage of phage therapy despite the inevitable emergence of phage-resistant strains. Bacteriophages (or specific phage-derived products) can enhance antimicrobial efficacy by reducing bacterial virulence via the alteration of basic bacterial structures, primarily of the cellular wall and membrane. Although several issues remain open regarding their effective clinical application, it appears that phage-based therapeutics in combination with antibiotics can provide an effective solution to the spread of antimicrobial resistance.

Introduction: Vault particles are large cytoplasmic ribonucleoprotein particles that participate in inflammation. The aim of this study was to assess the diagnostic and prognostic value of major vault protein (MVP) in patients with inflammation, in order to determine whether MVP could be used as a biomarker for infection or inflammation. We also aimed to compare the diagnostic impact of MVP compared to other conventional measurements, such as CRP or white blood cell (WBC) counts. Methods: CRP and MVP levels were measured in 111 sera samples from 85 patients with inflammation admitted to a tertiary-care hospital and 26 healthy individuals during an 18-month period (2019–2020), using nephelometry and a custom MVP sandwich ELISA assay, respectively. In addition, WBC counts were measured using a commercial assay. Results: MVP levels were found to be elevated in patients with inflammation compared to healthy individuals (p < 0.0001). Moreover, MVP levels were higher in patients with inflammation due to an infectious etiology compared to those with non-infectious etiology (p = 0.0006). MVP levels significantly decreased during the first four days of infection in response to antibiotic treatment, while CRP levels showed a less-sensitive decline. An ROC curve analysis demonstrated that MVP and CRP have similarly high diagnostic accuracy, with AUCs of 0.955 and 0.995, respectively, followed by WBCs with an AUC of 0.805. Conclusions: The ROC curves demonstrated that MVP has the potential to serve as a diagnostic biomarker for inflammation and infection. Additionally, MVP levels may reflect the efficacy of antibiotic treatment.

The storm Daniel and subsequent floods hit the Region of Thessaly (Greece) in early September 2023, causing extensive damage to the built environment (buildings, networks, and infrastructure), the natural environment (water bodies and soil), and the population (fatalities, injured, homeless, and displaced people). Additionally, the conditions and factors favorable for indirect public health impact (infectious diseases) emerged in the flood-affected communities. The factors had to do with infectious diseases from rodents and vectors, injuries, respiratory infections, water contamination, flood waste and their disposal sites as well as structural damage to buildings and the failures of infrastructure. The conditions that evolved necessitated the mobilization of the Civil Protection and Public Health agencies not only to cope with the storm and subsequent floods but also to avoid and manage indirect public health impact. The instructions provided to affected residents, health experts, and Civil Protection staff were consistent with the best practices and lessons learned from previous disasters. The emphasis should be on training actions for competent agencies, as well as education and increasing the awareness of the general population. Non-structural and structural measures should be implemented for increasing the climate resilience of infrastructures including the health care systems within a One Health approach.

The escalating global rates of precancerous lesions associated with human papillomavirus (HPV) types not targeted by current vaccines underscore the need to explore the prevalence of HPV types within the Greek female population and their involvement in precancerous lesion development. In the current study, we enrolled a cohort of 253 women aged 18 to 65 years, residing in Greece, who underwent routine screening in three tertiary care referral hospitals. Each participant completed a demographic questionnaire. An HPV DNA test was administered using the VisionArray® HPV kit (ZytoVision GmbH) to qualitatively detect and genotype 41 clinically relevant HPV genotypes. Of all 253 women examined, 114 (45.1%) tested positive for HPV DNA. The primary type detected was HPV51 (high-risk), present in 21 women (8.3% of the total), followed by HPV54 (low-risk) in 17 women (6.7%); HPV16 (high-risk) ranked third, identified in 14 women (5.5%). Among the HPV-positive women, 65 were positive for high-risk HPV types (57% of HPV-positive women) and were referred for colposcopy and cervical biopsy. These procedures identified 24 women with cervical intraepithelial neoplasia 1 (CIN1) lesions and 2 with cervical intraepithelial neoplasia 2 (CIN2) lesions. The most prevalent HPV type among women with CIN1 lesions was HPV16, found in nine (37.5%) women, while HPV51 ranked second, identified in six (25%) women. Both women with CIN2 lesions tested positive for HPV16, whereas one of them was also tested positive for HPV45. Our study is the first to report the prevalence of HPV51 among HPV-positive women in the Greek female population. This highlights the need for further research to fully understand the potential of HPV types not covered by current vaccines, such as HPV51, to cause high-grade lesions or cervical cancer.

Substantial knowledge gaps exist concerning the varying durations of peripherally inserted central catheter (PICC) placements that lead to either central line-associated bloodstream infection (CLABSI) or catheter colonization. We aimed to compare PICCs dwell time between patients who developed CLABSIs due to multidrug-resistant microorganisms (MDROs) and patients with catheter colonization by MDROs. Data from 86 patients admitted consecutively to a tertiary-care hospital from 2017 to 2020 were retrospectively analyzed. The mean dwell time was 25.73 ± 16.19 days in the PICC-CLABSI group and 16.36 ± 10.28 days in the PICC-colonization group (p = 0.002). The mean dwell time was 17.38 ± 9.5 days in the PICC-MDRO group and 22.48 ± 15.64 days in the PICC-non-MDRO group (p = 0.005). Within the PICC-CLABSI group, the mean dwell time for CLABSIs caused by MDROs was 21.50 ± 12.31 days, compared to 27.73 ± 16.98 days for CLABSIs caused by non-MDROs (p = 0.417). Within the PICC-colonization group, the mean dwell time was 15.55 ± 7.73 days in PICCs colonized by MDROs and 16.92 ± 11.85 days in PICCs colonized by non-MDROs (p = 0.124). The findings of the present study suggest that CLABSIs caused by MDROs in PICCs are associated with a shorter mean catheter dwell time compared to those caused by non-MDROs, underscoring the importance of considering infections by MDROs when evaluating PICC dwell times.

Our study seeks to provide a comprehensive assessment of leishmaniasis prevalence among blood donors, employing rigorous methodologies to inform public health initiatives and transfusion safety measures. A thorough literature search was conducted using electronic databases (Medline, Scopus, Web of Science, and Google Scholar) to identify the relevant studies reporting the prevalence of leishmaniasis among blood donors, gathering a wide range of studies encompassing different geographic locations and time periods. The pooled prevalence with a 95% confidence interval (CI) was estimated, and quality assessment, outlier analysis, and influential analysis were performed to ensure the robustness and validity of the findings. Our search and subsequent analyses led to the inclusion of thirty-five studies in our review. Using molecular diagnostic methods, the prevalence was estimated at 2.3% (95% CI 1–3.9%), while serological diagnostic methods indicated a higher prevalence rate of 4.5% (95% CI 2.8–6.7%). Notably, we observed significant heterogeneity among the included studies for each analysis. The observed heterogeneity highlights the need for future research to delve into the factors influencing leishmaniasis prevalence, with prospective and retrospective studies addressing the limitations identified in this review.

Background: Enterobacter cloacae, E. hormaechei and related subspecies remain the most clinically relevant among the Enterobacter cloacae complex (ECC). Carbapenemase-producing ECC strains are increasingly identified in hospital-acquired infections and usually belong to four main multilocus sequence types (MLST STs) named ST114, ST93, ST90 and ST78. Instead, ST182 has been sporadically reported among E. hormaechei strains, and recently, outbreaks of blaNDM-producing ST182 clonal strains have emerged. Herein, we aimed to investigate the presence of ST182 and explore its evolution and modes of blaNDM acquisition. Methods: A phylogenetic analysis of 646 MLST STs identified among 4685 E. hormaechei whole-genome sequencing (WGS) assemblies deposited in public repositories was performed, as well as an in silico comparative and phylogenomic analyses for 55 WGS assemblies of ST182. blaNDM-harboring contigs were also compared to published plasmid sequences. Results: ST182 E. hormaechei strains were recovered from patients on five continents during 2011–2021. They were divided into three major genomic clusters, comprising a separate clonal complex with six other STs. In 30 out of 55 ST182 WGS assemblies, blaNDM-harboring structures were identified that were similar to the plasmids predominant in Gram-negative bacteria, harboring resistance genes to multiple antibiotic classes and virulence genes. No associations between the genomic clusters and the country/continent of isolation or the presence and the plasmid types of the blaNDM-harboring contigs were observed. Conclusions: Our findings show that ST182 E. hormaechei strains have been identified in the past decade worldwide; 54.5% of them carried diverse blaNDM genetic structures, suggesting recent acquisition of the blaNDM alleles. Thus, blaNDM-harboring ST182 is an emerging multidrug-resistant and virulent lineage in ECC strains that requires close monitoring.

Abstract Background Central venous catheters (CVCs) and peripherally inserted central catheters (PICCs), have been widely used as intravascular devices in critically ill patients. However, they might evoke complications, such as catheter colonization that has been considered as predisposing factor for central line-associated bloodstream infections (CLABSIs). Although numerous studies have compared the risk of bloodstream infections between PICCs and CVCs, comparative studies on their colonization rates are limited. Objectives The episodes of catheter colonization in critically ill patients with CVCs or PICCs were retrospectively analysed during a two-year period in a Greek tertiary care hospital and colonization rates, microbial profiles and antimicrobial susceptibility patterns were compared. Methods Clinical and laboratory data of consecutive hospitalized critically-ill patients who underwent PICC and CVC placement between May 2017–May 2019 were analysed. All catheters were examined by the semiquantitative culture technique for bacterial pathogens, either as a routine process after catheter removal or after suspicion of infection. Species identification and antimicrobial resistance patterns were determined by the Vitek2 automated system. Results During the survey period a total of 122/1187 (10.28%) catheter colonization cases were identified among CVCs and 19/639 (2.97%) cases among PICCs (p = 0.001). The colonization rate was 12.48/1000 catheter-days for the CVC group and 1.71/1000 catheter-days for the PICC group (p

The novel coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spread rapidly during the first months of 2020 and continues to expand in multiple areas across the globe. Molecular epidemiology has provided an added value to traditional public health tools by identifying SARS-CoV-2 clusters or providing evidence that clusters based on virus sequences and contact tracing are highly concordant. Our aim was to infer the levels of virus importation and to estimate the impact of public health measures related to travel restrictions to local transmission in Greece. Our phylogenetic and phylogeographic analyses included 389 full-genome SARS-CoV-2 sequences collected during the first 7 months of the pandemic in Greece and a random collection in five replicates of 3,000 sequences sampled globally, as well as the best hits to our data set identified by BLAST. Phylogenetic trees were reconstructed by the maximum likelihood method, and the putative source of SARS-CoV-2 infections was inferred by phylogeographic analysis. Phylogenetic analyses revealed the presence of 89 genetically distinct viruses identified as independent introductions into Greece. The proportion of imported strains was 41%, 11.5%, and 8.8% during the three periods of sampling, namely, March (no travel restrictions), April to June (strict travel restrictions), and July to September (lifting of travel restrictions based on thorough risk assessment), respectively. The results of phylogeographic analysis were confirmed by a Bayesian approach. Our findings reveal low levels of onward transmission from imported cases during summer and underscore the importance of targeted public health measures that can increase the safety of international travel during a pandemic. IMPORTANCE Our study based on current state-of-the-art molecular epidemiology methods suggests that virus screening and public health measures after the lifting of travel restrictions prevented SARS-CoV-2 onward transmission from imported cases during summer 2020 in Greece. These findings provide important data on the efficacy of targeted public health measures and have important implications regarding the safety of international travel during a pandemic. Our results can provide a roadmap about prevention policy in the future regarding the reopening of borders in the presence of differences in vaccination coverage, the circulation of the virus, and the presence of newly emergent variants across the globe.

The share of the elderly population is growing worldwide as life expectancy increases. Immunosenescence and comorbidities increase infectious diseases’ morbidity and mortality in older adults. Here, we aimed to summarize the latest findings on vaccines for the elderly against herpes zoster, influenza, respiratory syncytial virus (RSV), COVID-19, and pneumococcal disease and to examine vaccine recommendation differences for this age group in Europe and the United States. PubMed was searched using the keywords “elders” and “vaccine” alongside the disease/pathogen in question and paraphrased or synonymous terms. Vaccine recommendations were also sought in the European and US Centers for Disease Control and Prevention databases. Improved vaccines, tailored for the elderly, mainly by using novel adjuvants or by increasing antigen concentration, are now available. Significant differences exist between immunization policies, especially between European countries, in terms of the recipient’s age, number of doses, vaccination schedule, and implementation (mandatory or recommended). Understanding the factors that influence the immune response to vaccination in the elderly may help to design vaccines that offer long-term protection for this vulnerable age group. A consensus-based strategy in Europe could help to fill the gaps in immunization policy in the elderly, particularly regarding vaccination against RSV and pneumococcus.

Carbapenem-resistant Gram-negative bacterial infections are a major public health threat due to the limited therapeutic options available. The introduction of the new β-lactam/β-lactamase inhibitors (BL/BLIs) has, however, altered the treatment options for such pathogens. Thus, four new BL/BLI combinations—namely, ceftazidime/avibactam, meropenem/vaborbactam, imipenem/relebactam, and ceftolozane/tazobactam—have been approved for infections attributed to carbapenem-resistant Enterobacterales species and Pseudomonas aeruginosa. Nevertheless, although these antimicrobials are increasingly being used in place of other drugs such as polymyxins, their optimal clinical use is still challenging. Furthermore, there is evidence that resistance to these agents might be increasing, so urgent measures should be taken to ensure their continued effectiveness. Therefore, clinical laboratories play an important role in the judicious use of these new antimicrobial combinations by detecting and characterizing carbapenem resistance, resolving the presence and type of carbapenemase production, and accurately determining the minimum inhibitor concentrations (MICs) for BL/BLIs. These three targets must be met to ensure optimal BL/BLIs use and prevent unnecessary exposure that could lead to the development of resistance. At the same time, laboratories must ensure that results are interpreted in a timely manner to avoid delays in appropriate treatment that might be detrimental to patient safety. Thus, we herein present an overview of the indications and current applications of the new antimicrobial combinations and explore the diagnostic limitations regarding both carbapenem resistance detection and the interpretation of MIC results. Moreover, we suggest the use of alternative narrower-spectrum antibiotics based on susceptibility testing and present data regarding the effect of synergies between BL/BLIs and other antimicrobials. Finally, in order to address the absence of a standardized approach to using the novel BL/BLIs, we propose a diagnostic and therapeutic algorithm, which can be modified based on local epidemiological criteria. This framework could also be expanded to incorporate other new antimicrobials, such as cefiderocol, or currently unavailable BL/BLIs such as aztreonam/avibactam and cefepime/taniborbactam.

Introduction: Exploring T cell response duration is pivotal for understanding immune protection evolution in natural SARS-CoV-2 infections. The objective of the present study was to analyze the T cell immune response over time in individuals who were both vaccinated and COVID-19-naive and had undetectable levels of SARS-CoV-2 IgG antibodies at the time of testing. Methods: We performed a retrospective descriptive analysis using data extracted from the electronic medical records of consecutive adult individuals who underwent COVID-19 immunity screening at a private healthcare center from September 2021 to September 2022. The study participants were divided into three groups according to the post-vaccination time period, as follows: group A (up to 3 months), group B (3–6 months), and group C (>6 months). T cell response was evaluated using the IGRA methodology T-SPOT®.COVID. Results: Of the total number of subjects (n = 165), 60/165 (36.4%) had been vaccinated in the last 3 months (group A), 57/165 (34.5%) between 3 and 6 months (group B), and 48/165 (29.1%) at least 6 months prior to the examination day (group C). T cell positivity was reported in 33/60 (55.0%) of group A, 45/57 (78.9%) of group B, and 36/48 (75%) of group C (p < 0.007). No statistically significant differences were revealed in the spot-forming cell (SFC) count among groups, with mean SFC counts of 75.96 for group A, 89.92 for group B, and 83.58 for group C (Kruskal–Wallis test, p = 0.278). Conclusions: Our findings suggest that cellular immunity following SARS-CoV-2 vaccination may endure for at least six months, even in the presence of declining or absent IgG antibody levels.

Abstract Background There are differences in infection prevention and control (IPC) policies to prevent transmission of highly resistant microorganisms (HRMO). The aim of this study is to give an overview of the IPC policy of six European hospitals and their HRMO prevalence, to compare the IPC policies of these hospitals with international guidelines, and to investigate the hospitals’ adherence to their own IPC policy. Methods The participating hospitals were located in Salzburg (Austria), Vienna (Austria), Kayseri (Turkey), Piraeus (Greece), Rome (Italy) and Rotterdam (The Netherlands). Data were collected via an online survey. Questions were aimed at prevalence rates in the years 2014, 2015, 2016 of carbapenemase-producing Klebsiella pneumoniae (CPK), carbapenemase-producing Pseudomonas aeruginosa (CPPA), vancomycin-resistant Enterococcus faecium (VRE) and hospitals’ IPC policies of 2017. Implemented IPC measures (i.e. with a self-reported adherence of > 90%) were counted (26 points maximal). Results The self-reported prevalence of CPK per year was low in the Austrian and Dutch hospitals and high in the Turkish and Greek hospitals. CPPA was highly prevalent in the Turkish hospital only, while the prevalence of VRE in four hospitals, except the Austrian hospitals which reported lower prevalence numbers, was more evenly distributed. The Dutch hospital had implemented the most IPC measures (n = 21), the Turkish and Greek hospitals the least (n = 14 and 7, respectively). Conclusion Hospitals with the highest self-reported prevalence of CPK and CPPA reported the least implemented IPC measures. Also, hospitals with a higher prevalence often reported a lower adherence to own IPC policy.

ABSTRACT: Objectives: In this communication, we describe the emergence of the mcr-1 colistin resistance gene in a blaCTX-M-32 extended-spectrum–β-lactamase-producing Escherichia coli isolate recovered from a pediatric patient in Greece. Methods: Bacterial identification and antimicrobial susceptibility testing were performed with the VITEK2 automated system and broth microdilution. Detection of resistance genes, assignment to sequence type, in silico plasmid detection, and virulence factors were carried out using ResFinder, MLST 2.0, PlasmidFinder 2.1., and VirulenceFinder 2.0, respectively. PlasmidSPAdes v3.11.1 was used to assemble the plasmid contigs. The mcr-1.1-containing plasmid was analyzed for insertion sequence elements using ISfinder. Phylogenetically relevant sequences of the plasmid were identified using the Microbe BLASTN suite. Results: The microorganism was assigned to sequence type 48 and carried four plasmids of different incompatibility groups. The specific mcr-1.1 allele was located in a 32.722 bp plasmid belonging to the IncX4 group with no additional resistance genes. Conclusion: To the best of our knowledge, this is the first detection of mcr-1 in a human specimen in our country. A potential spread of mcr-1 in Greece is concerning because of the existing high rates of carbapenem resistance and colistin usage as a last resort regimen.

Abstract Background Peripherally inserted central venous catheters (PICCs) serve as an alternative to short-term central venous catheters (CVCs) for providing intravenous access in hospitalized patients. Although a number of studies suggest that PICCs are associated with a lower risk of central line-associated bloodstream infections (CLABSIs) than CVCs, recent data concerning specific patient groups support the contrary. In this regard, we are comparing CVC- and PICC-related CLABSI rates developed in a selected group of critically ill inpatients and evaluating the CLABSI microbiological distribution. Methods The study was conducted at a tertiary care hospital in Greece between May 2017 and May 2019. We performed a two-year retrospective analysis of the data collected from medical records of consecutive adult patients who underwent PICC or CVC placement. Results A total of 1187 CVCs placed for 9774 catheter-days and 639 PICCs placed for 11,110 catheter-days, were reported and analyzed during the study period. Among CVCs, a total of 59 (4.9%) CLABSIs were identified, while among PICCs, 18 (2.8%) cases presented CLABSI (p = 0.029). The CLABSI incidence rate per 1,000 catheter-days was 6.03 for CVC group and 1.62 for PICC group (p

ABSTRACT Amino acids in variable positions of proteins may be correlated, with potential structural and functional implications. Here, we apply exact tests of independence in R × C contingency tables to examine noise-free associations between variable positions of the SARS-CoV-2 spike protein, using as a paradigm sequences from Greece deposited in GISAID (N = 6,683/1,078 full length) for the period 29 February 2020 to 26 April 2021 that essentially covers the first three pandemic waves. We examine the fate and complexity of these associations by network analysis, using associated positions (exact P ≤ 0.001 and Average Product Correction ≥ 2) as links and the corresponding positions as nodes. We found a temporal linear increase of positional differences and a gradual expansion of the number of position associations over time, represented by a temporally evolving intricate web, resulting in a non-random complex network of 69 nodes and 252 links. Overconnected nodes corresponded to the most adapted variant positions in the population, suggesting a direct relation between network degree and position functional importance. Modular analysis revealed 25 k-cliques comprising 3 to 11 nodes. At different k-clique resolutions, one to four communities were formed, capturing epistatic associations of circulating variants (Alpha, Beta, B.1.1.318), but also Delta, which dominated the evolutionary landscape later in the pandemic. Cliques of aminoacidic positional associations tended to occur in single sequences, enabling the recognition of epistatic positions in real-world virus populations. Our findings provide a novel way of understanding epistatic relationships in viral proteins with potential applications in the design of virus control procedures. IMPORTANCE Paired positional associations of adapted amino acids in virus proteins may provide new insights for understanding virus evolution and variant formation. We investigated potential intramolecular relationships between variable SARS-CoV-2 spike positions by exact tests of independence in R × C contingency tables, having applied Average Product Correction (APC) to eliminate background noise. Associated positions (exact P ≤ 0.001 and APC ≥ 2) formed a non-random, epistatic network of 25 cliques and 1–4 communities at different clique resolutions, revealing evolutionary ties between variable positions of circulating variants and a predictive potential of previously unknown network positions. Cliques of different sizes represented theoretical combinations of changing residues in sequence space, allowing the identification of significant aminoacidic combinations in single sequences of real-world populations. Our analytic approach that links network structural aspects to mutational aminoacidic combinations in the spike sequence population offers a novel way to understand virus epidemiology and evolution.

ABSTRACT Significant variation in minimal inhibitory concentrations (MIC) has been reported for amphotericin B (AMB) and C. auris, depending on the antifungal susceptibility testing (AFST) method. Although the Sensititre YeastOne (SYO) is widely used in routine laboratory testing, data regarding its performance for the AFST of C. auris are scarce. We tested AMB against 65 C. auris clinical isolates with the SYO and the reference methodology by the Clinical and Laboratory Standards Institute (CLSI). The essential agreement (EA, ±1 dilution) between the two methods and the categorical agreement (CA) based on the Centers for Disease Control and Prevention (CDC)’s tentative breakpoint of MIC ≥ 2 mg/L were determined. The SYO wild type upper limit value (WT-UL) was determined using the ECOFFinder. The modal (range) CLSI growth inhibitory MIC was lower than the SYO colorimetric MIC [1(0.25-1) versus 2(1-8) mg/L, respectively]). The CLSI-colorimetric SYO EA was 29% and the CA was 11% (89% major errors; MaE). MaE were reduced when the SYO WT-UL of 8 mg/L was used (0% MaE). Alternatively, the use of SYO growth inhibition endpoints of MIC-1 (75% growth inhibition) or MIC-2 (50% growth inhibition) resulted in 88% CA with 12% MaE and 97% CA with 3% MaE, respectively. In conclusion, SYO overestimated AMB resistance in C. auris isolates when colorimetric MICs, as per SYO instructions and the CDC breakpoint of 2 mg/L, were used. This can be improved either by using the method-specific WT-UL MIC of 8 mg/L for colorimetric MICs or by determining growth inhibition MIC endpoints, regardless of the color. IMPORTANCE Candida auris is an emerging and frequently multidrug-resistant fungal pathogen that accounts for life-threatening invasive infections and nosocomial outbreaks worldwide. Reliable AF is important for the choice of the optimal treatment. Commercial methods are frequently used without prior vigorous assessment. Resistance to AMB was over-reported with the commercial colorimetric method Sensititre YeastOne (SYO). SYO produced MICs that were 1 to 2 twofold dilutions higher than those of the reference CLSI method, resulting in 89% MaE. MaE were reduced using a SYO-specific colorimetric wild type upper limit MIC value of 8 mg/L (0%) or a 50% growth inhibition endpoint (3%).

Intestinal microorganisms play a crucial role in shaping the host immunity and maintaining homeostasis. Nevertheless, alterations in gut bacterial composition may occur and these alterations have been linked with the pathogenesis of several diseases. In surgical practice, studies revealed that the microbiome of patients undergoing surgery changes and several post-operative complications seem to be associated with the gut microbiota composition. In this review, we aim to provide an overview of gut microbiota (GM) in surgical disease. We refer to several studies which describe alterations of GM in patients undergoing different types of surgery, we focus on the impacts of peri-operative interventions on GM and the role of GM in development of post-operative complications, such as anastomotic leak. The review aims to enhance comprehension regarding the correlation between GM and surgical procedures based in the current knowledge. However, preoperative and postoperative synthesis of GM needs to be further examined in future studies, so that GM-targeted measures could be assessed and the different surgery complications could be reduced.

Background: The use of peripherally inserted central catheters (PICCs) as an alternative to central venous catheters (CVCs) has steadily risen over the last two decades. However, there is an ongoing debate regarding research evidence that supports any clear advantages or disadvantages of them compared to traditional central venous lines. The present study was conducted to compare the indwelling time of CVC and PICC placements leading to microbial colonization by multidrug-resistant microorganisms (MDROs) in critically ill patients. Methods: A single-center retrospective descriptive study was performed that reviewed the medical records of critically ill patients with colonized CVCs and PICCs who were hospitalized during a 24-month period (May 2019–May 2021). To evaluate the association between indwelling time of catheter placement and colonization rates, events were categorized into three groups, each representing a one-week time interval of catheter indwelling time: group 1: ≤7 days, group 2: 8–14 days, and group 3: >14 days. Results: A total of 207 hospitalized patients with colonized PICCs or CVCs were included in the study. Of these, 144 (69.5%) had a CVC placement and 63 (30.5%) had a PICC placement. The overall colonization rate (per 1.000 catheter/days) was 14.73 in the CVC and 5.67 in the PICC cohort (p = 0.003). In the group of PICCs, 12/63 (19%) of the pathogens were MDROs and 51/63 (81%) were non-MDROs, while in the group of CVCs, 86/144 (59.7%) were MDROs and 58/144 (40.3%) were non-MDROs (p < 0.001). The colonization rate in the CVC cohort, was 6.98 for group 1, 21.57 for group 2, and 21.6 for group 3 (p = 0.019). The colonization rate of MDROs was 3.27 for group 1, 14.47 for group 2, and 12.96 for group 3 (p = 0.025). Regarding the PICC cohort, the colonization rate was 1.49 for group 1, 3.19 for group 2, and 8.99 for group 3 (p = 0.047). No significant difference existed between the three groups in terms of MDRO pathogens, with the colonization rate being 0 for group 1, 0.8 for group 2, and 1.69 for group 3 (p = 0.78). Within the CVC cohort, the most common isolated microorganism was MDR Acinetobacter baumannii (n = 44; 30.6%), followed by MDR Klebsiella pneumoniae (n = 27; 18.7%). In the PICC cohort, the predominant isolated microorganism was Candida non-albicans (n = 15; 23.8%), followed by Candida albicans, coagulase-negative staphylococci, and MDR Klebsiella pneumoniae in equal numbers (n = 6; 9.5%). Conclusions: Our findings show that while the indwelling time of PICC placement was longer compared to CVCs, its colonization rate was considerably lower. Furthermore, high colonization rates by microorganisms, especially MDROs, arose later during catheterization in PICCs compared to CVCs, suggesting that in terms of vascular infections, PICCs may be a safer alternative to conventional CVCs for long-term intravenous access.

Despite the outstanding progress that has been made in the prevention, detection, and management of hepatitis B during the past decades, hepatitis B remains a problem among healthcare personnel (HCP) in many countries. We reviewed studies on all aspects of hepatitis B in HCP published from 2017 through April 2023. They revealed wide variations on the prevalence of infection among HCP, ranging from 0.6% in Europe to >8.7% in Africa, almost always in association with very low vaccination rates. Many studies found a significant association between HCP’s knowledge about hepatitis B and hepatitis B vaccines, their vaccination status, and practices. This research also discloses global inequities regarding vaccination policies against hepatitis B, free-of-charge vaccinations, and access to post-exposure prophylaxis (PEP). Strategies to prevent and manage accidental exposures are needed in order to reduce the burden of hepatitis B on HCP, while written policies for all aspects of infection prevention, protective equipment, and PEP should be available. Lastly, HCP should be accordingly educated. These are all imperative given the decline of routine vaccinations in the COVID-19 era, particularly in countries with fragile vaccination programs, and the disruptions of interventions for hepatitis B that are expected to provide a pool of virus transmission to future generations.

Abstract Background Central line–associated bloodstream infections (CLABSIs) remain a critical and possibly fatal outcome of hospitalization. Use of central venous catheter (CVC) bundles can considerably reduce CLABSI rates in hospitalized patients. However, despite widespread adoption of these bundles in hospitals worldwide, CLABSIs still remain prevalent. The aim of the present study was to determine whether longer duration of CVCs placement is related to CLABSIs in hospitalized adults, despite the implementation of preventive bundles. Also to analyse CLABSI pathogens distribution and antimicrobial resistance profiles in different time intervals of catheterization. Methods A retrospective study was performed among hospitalized patients who had a CVC inserted during a 24-month period (May 2017–May 2019) and developed CLABSIs. To evaluate the association between CVC placement duration and CLABSI events, we categorized events into three groups, each representing a 10-day time interval. Results A total of 59 CLABSI cases were identified among 9774 catheter/days. The CLABSI incidence rate per 1000 catheter/days was 4.80 for duration of catheterization up to 10 days, 5.92 for duration of 11–20 days, and 8.64 for duration > 20 days(p = 0.007). The CLABSI incidence rate per 1000 catheter/days due to multidrug-resistant organisms (MDROs) among the three groups was 2.62 for catheter duration of up to 10 days, 3.83 for 11–20 days, and 3.46 for > 20 days (p = 0.14). Among CLABSIs, the most common microorganism identified was multidrug-resistant Acinetobacter baumannii, which accounted for 27.1% of the cases. There was no significant difference in the type of CLABSI pathogens isolated among the 3 groups. Conclusions Our findings suggest that duration of CVC placement remains an important risk factor for CLABSIs in hospitalized patients, even after the adoption of prevention bundles. The high prevalence of MDROs in our setting reflects the local epidemiology, highlighting a significant threat of urgent public health concern.

The continued rise in antimicrobial resistance poses a serious threat to public health worldwide. The use of phages that can have bactericidal activity without disrupting the normal flora represents a promising alternative treatment method. This practice has been successfully applied for decades, mainly in Eastern Europe, and has recently been used as an emergency therapy for compassionate care in the United States. Here, we provide a comprehensive review of the pre-clinical and clinical applications of phage therapy concerning three major Gram-negative pathogens: Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii. The advantages and the challenges of expanding the usage of phages as an alternative or adjunctive treatment for antimicrobial-resistant bacterial infections are discussed. We emphasize the virologic complexities of using the highly adaptable phage populations as molecular tools, along with antibiotic chemical compounds, to effectively combat rapidly coevolving pathogenic bacteria in the host microenvironment. Pre-clinical studies, isolated clinical reports and a few randomized clinical trials have shown that bacteriophages can be effective in treating multidrug-resistant bacterial infections. The ability of some phages to revert the resistance against antibiotics, and possibly also against the human complement and other phages, appears to be a great advantage of phage therapy despite the inevitable emergence of phage-resistant strains. Bacteriophages (or specific phage-derived products) can enhance antimicrobial efficacy by reducing bacterial virulence via the alteration of basic bacterial structures, primarily of the cellular wall and membrane. Although several issues remain open regarding their effective clinical application, it appears that phage-based therapeutics in combination with antibiotics can provide an effective solution to the spread of antimicrobial resistance. [ABSTRACT FROM AUTHOR]

Introduction: Vault particles are large cytoplasmic ribonucleoprotein particles that participate in inflammation. The aim of this study was to assess the diagnostic and prognostic value of major vault protein (MVP) in patients with inflammation, in order to determine whether MVP could be used as a biomarker for infection or inflammation. We also aimed to compare the diagnostic impact of MVP compared to other conventional measurements, such as CRP or white blood cell (WBC) counts. Methods: CRP and MVP levels were measured in 111 sera samples from 85 patients with inflammation admitted to a tertiary-care hospital and 26 healthy individuals during an 18-month period (2019–2020), using nephelometry and a custom MVP sandwich ELISA assay, respectively. In addition, WBC counts were measured using a commercial assay. Results: MVP levels were found to be elevated in patients with inflammation compared to healthy individuals (p < 0.0001). Moreover, MVP levels were higher in patients with inflammation due to an infectious etiology compared to those with non-infectious etiology (p = 0.0006). MVP levels significantly decreased during the first four days of infection in response to antibiotic treatment, while CRP levels showed a less-sensitive decline. An ROC curve analysis demonstrated that MVP and CRP have similarly high diagnostic accuracy, with AUCs of 0.955 and 0.995, respectively, followed by WBCs with an AUC of 0.805. Conclusions: The ROC curves demonstrated that MVP has the potential to serve as a diagnostic biomarker for inflammation and infection. Additionally, MVP levels may reflect the efficacy of antibiotic treatment. [ABSTRACT FROM AUTHOR]

GII.4 noroviruses have caused the overwhelming majority of norovirus-related gastroenteritis cases during the past two decades. However, a trend towards the emergence of new genotypes and novel GII.4 variants provided the impetus to explore further the changing patterns in norovirus epidemiology during the present study. Genotyping of 60 norovirus strains detected during a period of 33 months (January 2016–October 2018) was performed on the basis of the capsid VP1-coding ORF2 gene sequence. All norovirus strains detected were classified into seven genotypes, six of which belonged to genogroup GII. GII.2 was the dominant genotype till February 2017, whereas GII.4 prevailed thereafter. Most of the GII.4 strains were of the Sydney_2012 variant, whereas five strains could not be classified. Further recombination analysis at the ORF1/ORF2 gene junction revealed that 23 out of 24 strains were recombinant, thereby showcasing the significant role of genetic recombination in norovirus evolution and epidemiology. Continuous genomic surveillance and molecular characterization are essential for tracking norovirus evolution, which could contribute to the elucidation of new aspects of virus–host interactions that potentially affect host morbidity and epidemiology.

Background: Immune response to SARS-CoV-2 is crucial for preventing reinfection or reducing disease severity. T-cells’ long-term protection, elicited either by COVID-19 vaccines or natural infection, has been extensively studied thus far; however, it is still attracting considerable scientific interest. The aim of the present epidemiological study was to define the levels of T-cellular immunity response in a specific group of unvaccinated individuals from the general population with a prior confirmed COVID-19 infection and no measurable levels of IgG antibodies. Methods: We performed a retrospective descriptive analysis of data collected from the medical records of consecutive unvaccinated individuals recovered from COVID-19, who had proceeded to a large private medical center in the Attica region from September 2021 to September 2022 in order to be examined on their own initiative for SARS-CoV-2 T-cell immunity response. The analysis of T-cell responses was divided into three time periods post infection: Group A: up to 6 months; Group B: 6–12 months; Group C: >12 months. The SARS-CoV-2 T-cell response was estimated against spike (S) and nucleocapsid (N) structural proteins by performing the T-SPOT. COVID test methodology. SARS-CoV-2 IgG antibody levels were measured by the SARS-CoV-2 IgG II Quant assay (Abbott Diagnostics). Results: A total of 182 subjects were retrospectively included in the study, 85 females (46.7%) and 97 (53.3%) males, ranging from 19 to 91 years old (mean 50.84 ± 17.2 years). Among them, 59 (32.4%) had been infected within the previous 6 months from the examination date (Group A), 69 (37.9%) had been infected within a time period > 6 months and p = 0.27). T-cell reaction against the N antigen was present in 45/58 (77.6%) of Group A, 61/69 (88.4%) of Group B and 36/54 (66.7%) of Group C (chi square, p = 0.02). The median Spot-Forming Cells (SFC) count for the S antigen was 18 (range from 0–160) in Group A, 19 (range from 0–130) in Group B and 17 (range from 0–160) in Group C (Kruskal–Wallis test, p = 0.11; pairwise comparisons: groups A–B, p = 0.95; groups A–C, p = 0.89; groups B–C, p = 0.11). The median SFCs count for the N antigen was 14.5 (ranging from 0 to 116) for Group A, 24 (ranging from 0–168) in Group B and 16 (ranging from 0–112) for Group C (Kruskal–Wallis test, p = 0.01; pairwise comparisons: groups A–B, p = 0.02; groups A–C, p = 0.97; groups B–C, p = 0.03). Conclusions: Our data suggest that protective adaptive T-cellular immunity following natural infection by SARS-CoV-2 may persist for over 12 months, despite the undetectable humoral element.

Earthquakes have the potential to cause severe and widespread structural damage to buildings and infrastructure in the affected area. Earthquake debris mainly results from building collapses during intense ground motion and the emergency demolition of damaged and unstable buildings following a devastating earthquake. Debris management constitutes a major challenge that must be met by all those participating in disaster management as it poses threats to both the natural environment and public health in an earthquake-affected area. This narrative review examines the hazards that arise throughout the early phases of debris removal, when personnel operate in disaster-affected areas, to the last steps of sorting and disposal. Furthermore, emphasis is also given to the environmental impact caused by unregulated debris disposal on natural habitats that are highly sensitive and susceptible to hazardous substances and materials found in the debris. In the same framework, measures are proposed for alleviating the negative impacts of debris management on the well-being of all individuals involved, including workers, volunteers, and the local community, as well as the surrounding natural environment, encompassing soil, surface and groundwater, as well as air quality.

Brucellosis remains an important zoonotic disease in several parts of the world; in Greece, although it is declining, it is still endemic, affecting both the financial and public health sectors. The current study was undertaken to investigate the presence and distribution of virulence-associated genes among Brucella spp. clinical strains isolated during 2001–2022. Species identification was performed using conventional methodology and Bruce-ladder PCR. The presence of the virulence genes mviN, manA, wbkA, perA, omp19, ure, cbg and virB was investigated using PCR. During the study period, a total of 334 Brucella isolates were identified, of which 328 (98.2%) were detected from positive blood cultures; 315 (94.3%) of the isolates were identified as B. melitensis, whilst the remaining 16 (4.8%) and 3 (0.9%) were identified as B. abortus and B. suis, respectively. Notably, two of the B. melitensis were assigned to the REV-1 vaccine strain type. The presence of the omp19, manA, mviN and perA genes was confirmed in all 315 B. melitensis isolates, while ure, wbkA, cbg and virB genes were detected in all but 9, 2, 1 and 1 of the isolates, respectively. All eight virulence genes were amplified in all B. abortus and B. suis isolates. The detection rate of virulence genes did not differ significantly among species. In conclusion, brucellosis is still considered a prevailing zoonotic disease in Greece, with the majority of the isolates identified as B. melitensis. The eight pathogenicity-associated genes were present in almost all Brucella isolates, although the ure gene was absent from a limited number of B. melitensis isolates.

Nosocomial outbreaks of multidrug-resistant (MDR) Enterobacter cloacae complex (ECC) are often reported worldwide, mostly associated with a small number of multilocus-sequence types of E. hormaechei and E. cloacae strains. In Europe, the largest clonal outbreak of blaNDM-1-producing ECC has been recently reported, involving an ST182 E. hormaechei strain in a Greek teaching hospital. In the current study, we aimed to further investigate the genetic make-up of two representative outbreak isolates. Comparative genomics of whole genome sequences (WGS) was performed, including whole genome-based taxonomic analysis and in silico prediction of virulence determinants of the bacterial cell surface, plasmids, antibiotic resistance genes and virulence factors present on genomic islands. The enterobacterial common antigen and the colanic antigen of the cell surface were identified in both isolates, being similar to the gene clusters of the E. hormaechei ATCC 49162 and E. cloacae ATCC 13047 type strains, whereas the two strains possessed different gene clusters encoding lipopolysaccharide O-antigens. Other virulence factors of the bacterial cell surface, such as flagella, fimbriae and pili, were also predicted to be encoded by gene clusters similar to those found in Enterobacter spp. and other Enterobacterales. Secretion systems and toxin–antitoxin systems, which also contribute to pathogenicity, were identified. Both isolates harboured resistance genes to multiple antimicrobial classes, including β-lactams, aminoglycosides, quinolones, chloramphenicol, trimethoprim, sulfonamides and fosfomycin; they carried blaTEM-1, blaOXA-1, blaNDM-1, and one of them also carried blaCTXM-14, blaCTXM-15 and blaLAP-2 plasmidic alleles. Our comprehensive analysis of the WGS assemblies revealed that blaNDM-1-producing outbreak isolates possess components of the bacterial cell surface as well as genomic islands, harbouring resistance genes to several antimicrobial classes and various virulence factors. Differences in the plasmids carrying β-lactamase genes between the two strains have also shown diverse modes of acquisition and an ongoing evolution of these mobile elements.