Angiopoietins as Predictor Indexes in COVID-19 Patients in Delta and Omicron Waves.

This study aimed to explore the correlation between Angiopoietin-1 (Ang-1) and Angiopoietin-2 (Ang-2) concentrations and the Angiopoietin-2/Angiopoietin-1 ratio (Ang-2/Ang-1) with clinical outcomes, potentially serving as disease severity and survival biomarkers. A study at AHEPA University Hospital involved 90 Coronavirus Disease 2019 (COVID-19) adult patients, 30 hospitalized intensive care units (ICU), 30 inward units (non-ICU), and 30 asymptomatic non-hospitalized individuals as controls. Estimated endothelial dysfunction markers related to angiogenesis were measured. There was a statistically significant difference only between outpatient and hospitalized patients (non-ICU-ICU groups) for the Ang-1 and Ang-2 indices. The Ang-2/Ang-1 ratio has differed significantly among the individual patient groups. An ROC analysis was conducted to find an optimal threshold for distinguishing between (outpatients-non-ICU) and (non-ICU-ICU) groups. It was based on Youden's index of 0.1122 and 0.3825, respectively. The Ang-1, Ang-2 levels, and Ang-2/Ang-1 ratio were analyzed as severity indicators in COVID-19 patients. The Ang-2/Ang-1 ratio demonstrated better prognostic and diagnostic utility than individual biomarker levels. Monitoring the Ang-2/Ang-1 ratio can identify COVID-19 patients at risk and assist clinicians in tailoring treatment strategies to improve outcomes.

Multidrug-resistant organism bloodstream infection and hospital acquisition among inpatients in three tertiary Greek hospitals during the COVID-19 era.

From 2019 (pre-COVID-19) to 2022 (COVID-19 years), three tertiary Greek hospitals monitored MDRO bloodstream infection (BSI) and hospital acquisition relying on laboratory data. Surveillance covered carbapenem-resistant Enterobacterales (CRE), Acinetobacter baumannii (CRAB), Pseudomonas aeruginosa (CRPA), vancomycin-resistant enterococci (VRE), and methicillin-resistant Staphylococcus aureus (MRSA), in intensive care units (ICUs) and non-ICUs. Non-ICUs experienced significant increases in CRE, CRAB and VRE during the pandemic. In ICUs, CRE increased in 2021, CRAB in 2020 and 2021, and VRE in 2021 and 2022. KPC predominated among CRE. MDRO BSI and hospital acquisition incidence rates increased, driven by CRE and CRAB.

Candida auris: Outbreak, surveillance and epidemiological monitoring in Northern Greece.

Candida auris is an emerging fungal pathogen associated with multi-drug resistance rates and widespread outbreaks in hospitals and healthcare units worldwide. Sequencing studies have revealed that different clonal lineages of the fungus seem to be prevalent among distinct geographical sites. The first case of C. auris in Northern Greece was reported in Thessaloniki in October 2022, almost 2 years after the first isolation in Greece (Athens 2019). The Mycology Laboratory of the Medical School of Aristotle University of Thessaloniki stands as the reference laboratory for fungal diseases in Northern Greece and a meticulous search for the yeast, in plenty of suspicious samples, has been run since 2019 in the Lab as well as a retrospective analysis of all its yeasts' collection, back to 2008, with negative results for the presence of C. auris. Here, are presented the findings concerning the outbreak and surveillance of C. auris in Northern Greece, mainly the region of Thessaloniki and the broader area of Macedonia, from October 2022 until August 2023. The isolates from Northern Greece continue to fall in Clade I and present with an almost equal and stable sensitivity profile until now.

The study concerns the outbreak of Candida auris in Northern Greece since October 2022 and the effort for surveillance and epidemiological monitoring. All isolates continue to fall in Clade I and present with an almost equal and stable sensitivity profile till now.

Clostridioides difficile infection in patients with and without COVID-19 during the pandemic: A retrospective cohort study from a tertiary referral hospital.

OBJECTIVES: This study aims to detect the prevalence and specific characteristics of Clostridioides difficile infection (CDI) during the COVID-19 pandemic. METHODS: In this retrospective observational study, conducted in a tertiary hospital in Greece between May 2021 and October 2022, patients with CDI from COVID-19 and Internal Medicine wards were enrolled and compared based on epidemiological and disease-associated data. RESULTS: In total, 4322 patients were admitted, and 435 samples for CDI were analyzed, with 104/435 (23.9 %) sample positivity and 2.4 % prevalence. We observed an increased prevalence of CDI compared to the beginning of the COVID-19 pandemic (prevalence = 1.7 %, p = 0.003). 35.6 % of the CDI patients were hospitalized in the COVID-19 ward and 64.4 % in the Internal Medicine ward. COVID-19 patients were younger (p = 0.02) with a lower Charlson Comorbidity Index (CCI) compared to the Internal Medicine ward patients (p < 0.001). With regards to the origin of CDI cases, in the Internal Medicine ward, 68.7 % presented with Hospital-Onset CDI, 17.9 % with Community Onset-Healthcare Associated CDI and 13.4 % with Community Associated CDI, while in the COVID-19 ward, the respective percentages were 86.5 %, 5.4 % and 8.1 %. Finally, there was an increased CDI-related CFR (Case Fatality Ratio) in the Internal Medicine ward compared to the COVID-19 ward (28.4 % vs. 5.4 %, p = 0.001). CONCLUSIONS: Increased CDI prevalence and testing were observed compared to the beginning of the COVID-19 pandemic. Lower CDI-related CFR was observed in patients with COVID-19, which may be credited to the patients' significantly lower median age and CCI, as well as to the majority of deaths being due to respiratory failure.

Antimicrobial resistance rates of Streptococcus pyogenes in a Greek tertiary care hospital: 6-year data and literature review.

Streptococcus pyogenes is responsible for various clinical manifestations in patients of all ages worldwide. Worryingly, an increase in antibiotic resistance rates of S. pyogenes has been observed in many countries. In the present study, 6-year data are presented regarding the antibiotic resistance rates of S. pyogenes in our hospital. During this period, a total of 52 S. pyogenes isolates were recovered from 52 patients and antimicrobial susceptibility testing was performed for 49 isolates. All were susceptible to penicillin, ampicillin, cefotaxime, ceftriaxone, linezolid, moxifloxacin, rifampicin, vancomycin, teicoplanin, and tigecycline. Erythromycin and clindamycin resistance rates were 20.4% and 18.8% respectively. Resistance rates to tetracycline were 40.8%, to chloramphenicol 6.9%, and to levofloxacin 2%. Since macrolides are recommended as an alternative treatment in case of allergy to ß-lactams, the high macrolide resistance rates are causing concern. Because different phenotypic antimicrobial patterns for S. pyogenes have been observed in different geographic areas, epidemiological data is of considerable value for the appropriate treatment choices.

Distribution of serotypes and antibiotic resistance of invasive Pseudomonas aeruginosa in a multi-country collection.

BACKGROUND: Pseudomonas aeruginosa is an opportunistic pathogen that causes a wide range of acute and chronic infections and is frequently associated with healthcare-associated infections. Because of its ability to rapidly acquire resistance to antibiotics, P. aeruginosa infections are difficult to treat. Alternative strategies, such as a vaccine, are needed to prevent infections. We collected a total of 413 P. aeruginosa isolates from the blood and cerebrospinal fluid of patients from 10 countries located on 4 continents during 2005-2017 and characterized these isolates to inform vaccine development efforts. We determined the diversity and distribution of O antigen and flagellin types and antibiotic susceptibility of the invasive P. aeruginosa. We used an antibody-based agglutination assay and PCR for O antigen typing and PCR for flagellin typing. We determined antibiotic susceptibility using the Kirby-Bauer disk diffusion method. RESULTS: Of the 413 isolates, 314 (95%) were typed by an antibody-based agglutination assay or PCR (n = 99). Among the 20 serotypes of P. aeruginosa, the most common serotypes were O1, O2, O3, O4, O5, O6, O8, O9, O10 and O11; a vaccine that targets these 10 serotypes would confer protection against more than 80% of invasive P. aeruginosa infections. The most common flagellin type among 386 isolates was FlaB (41%). Resistance to aztreonam (56%) was most common, followed by levofloxacin (42%). We also found that 22% of strains were non-susceptible to meropenem and piperacillin-tazobactam. Ninety-nine (27%) of our collected isolates were resistant to multiple antibiotics. Isolates with FlaA2 flagellin were more commonly multidrug resistant (p = 0.04). CONCLUSIONS: Vaccines targeting common O antigens and two flagellin antigens, FlaB and FlaA2, would offer an excellent strategy to prevent P. aeruginosa invasive infections.

Can bronchial secretion cultures identify the etiologic agent of COVID-19-associated pulmonary aspergillosis in ICU patients? Comparison with a species-specific Aspergillus PCR in serum.

Aspergillus spp. isolated from non-BAL cultures of coronavirus disease 2019 (COVID-19)-associated pulmonary aspergillosis (CAPA) patients may reflect colonization rather than infection. Sera (n = 181) from 49 adult ICU CAPA patients (24 probable and 25 possible CAPA) with bronchial secretions (BS) culture positive for Aspergillus spp. were collected and tested for Aspergillus DNA detection by species-specific real-time PCR. Overall, 30/49 (61%) patients were PCR positive. BS culture/serum PCR agreement was moderate (21/30; 70%). Based on serum PCR positive patients, all CAPAs were due to A. fumigatus (80%), A. flavus (10%), and A. terreus (10%). No A. niger/A. nidulans or mixed infections were found despite positive BS cultures.

Discordant results were observed between bronchial secretion cultures and species-specific serum PCR (30%) with A. fumigatus being by far the most common etiological agent of CAPA (80%). No A. niger/A. nidulans or mixed infections were found despite positive cultures.

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.

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.

Predominance of Clostridioides difficile PCR ribotype 181 in northern Greece, 2016-2019.

OBJECTIVES: The epidemiology of Clostridioides difficile infection (CDI) has undergone many changes since the beginning of this century and continues to evolve based on recent studies. Here, we performed a molecular analysis of C. difficile isolates in northern Greece across 10 health-care facilities, spanning from 2016 to 2019. METHODS: 221 C. difficile isolates were cultured from stool samples of hospitalized patients with diarrhea and screened by PCR for the presence of the toxin A (tcdA), toxin B (tcdB), the binary toxin (cdtA and cdtB) genes and the regulating gene of tcdC. PCR ribotyping of the cultured isolates was performed by a standardized protocol for capillary gel-based PCR ribotyping and an international database with well-documented reference strains. RESULTS: Thirty-five different PCR ribotypes were identified. The most common RTs identified were: 181 (36%, 80/221), 017 (10%, 21/221), 126 (9%, 19/221), 078 (4%, 9/221) and 012 (4%, 8/221). Notably, the predominant RT181, with toxin profile tcdA+tcdB+cdtA+cdtB+, was identified in seven out of ten participating hospitals. CONCLUSIONS: Multiple C. difficile ribotypes have been circulating in the northern Greece region with RTs 181 (closely related to 027), 017, 126 and 078 being predominant.

Performance evaluation of Alfred60AST rapid susceptibility testing directly from positive blood cultures in the routine laboratory workflow.

The aim of this study was to evaluate the performance of the new automated system Alfred60AST which is based on light scattering technology for rapid susceptibility testing directly from positive blood cultures as well as its applicability in the routine laboratory workflow. We evaluated 176 significant episodes of bacteremia due to 92 Gram-negative and 84 Gram-positive bacteria. The antimicrobial agents tested were ceftriaxone, ciprofloxacin, gentamicin, meropenem, piperacillin-tazobactam, and colistin for Gram negatives and cefoxitin, vancomycin, linezolid, and daptomycin for Gram positives. Concordance assessment was performed in comparison with our routine method, Vitek2 (bioMérieux). Discrepancies were resolved with MICRONAUT-S (Merlin) or E-test (bioMérieux). Out of 690 susceptibility determinations, 94.05% showed categorical agreement (CA) with the routine method and this percentage increased to 94.49 after discrepancy analysis. There were 1.45% very major errors, 3.33% major errors, and 1.16% minor errors (decreased to 1.45, 3.04, and 1.01 after discrepancy analysis). The CA for most of the antibiotics was above 90% except for daptomycin for Gram positives (87.30%) and ceftriaxone for Gram negatives (88.23%). The concordance was slightly better for Gram negative than for Gram-positive bacteria (94.30 versus 93.70%, respectively). The total turnaround time for a complete Alfred60AST result was 6-6.5h. The evaluated method gave rapid and reliable results in a few hours, versus 48h for the conventional one. Implementing this technology in routine workflow allows clinicians to optimize the treatment on the same day of blood culture positivity with potential positive clinical benefits and impact on antibiotic stewardship.

In vitro activity of ceftaroline against methicillin-resistant and methicillin-susceptible Staphylococcus aureus clinical isolates from a tertiary hospital in Greece.

Ceftaroline is a novel cephalosporin able to bind to and inhibit PBP2a, and thus active against methicillin-resistant Staphylococcus aureus. In the present study we assessed the in vitro activity of ceftaroline and comparators against a large sample of methicillin-resistant and methicillin-susceptible S. aureus isolates collected at our hospital. Overall, both MRSA and MSSA isolates in our study were sensitive to ceftaroline, even though the MIC range was higher for MRSAs (0.12-2 mg/L against ≤0.06-0.5 mg/L for MSSAs). Our results indicate that ceftaroline may be considered a reliable alternative for the treatment of MRSA.

Epidemiology and antimicrobial susceptibility of Staphylococcus lugdunensis in a Greek tertiary-care hospital.

Staphylococcus lugdunensis is considered more pathogenic than other coagulase-negative Staphylococci (CoNS), with its virulence resembling that of Staphylococcus aureus. We report a retrospective study of all S. lugdunensis infection cases during a 3.5-year period in a large tertiary university hospital in Greece. S.lugdunensis was susceptible to most tested antibiotics, although a high resistance percentage was found to clindamycin (27%) and erythromycin (25%). The susceptibility rate to penicillin was 49%, much lower than previously reported elsewhere, indicating that penicillin may not be an optimal treatment choice for S. lugdunensis infections in our region.

Bacteremia due to a toxin A-negative, B-positive Clostridioides difficile ribotype 017 strain.

Clostridioides difficile is the leading cause of healthcare-associated diarrhea. Although the incidence of C. difficile-associated diarrhea is increasing worldwide, bacteremia due to C. difficile is relatively rare and represents the least frequent extra-colonic manifestation of C. difficile infection. To date, only 60 C. difficile bacteremia cases with detailed clinical patient characteristics have been reported in the literature, and another 77 cases have been identified in epidemiological reports. We report a rare and fatal case of bacteremia due to C. difficile from a Greek hospital.

Antimicrobial Resistance and Antimicrobial Therapy of Clinically Relevant Bacteria.

Antimicrobial resistance is a major public health problem, and the World Health Organization (WHO) has warned that the current antibiotic armamentarium is not sufficient to face future challenges [...].

Pneumonia due to Ochrobactrum intermedium in an ICU patient.

Ochrobactrum intermedium is recognized as a rare emerging opportunistic pathogen mostly related with bloodstream infections. In this report, we describe the first clinical case of pneumonia due to O. intermedium. The case involved a 71-year old tetraplegic man hospitalized for vertebral fractures after falling from a ladder.

Rapid Reversal of Carbapenemase-Producing Pseudomonas aeruginosa Epidemiology from blaVIM- to blaNDM-harbouring Isolates in a Greek Tertiary Care Hospital.

Carbapenemase-producing Pseudomonas aeruginosa strains present a specific geographical distribution regarding the type of carbapenemase-encoding genes that they harbor. For more than twenty years, VIM-type enzymes were the only major carbapenemases that were detected among P. aeruginosa isolates in Greece until the emergence of NDM-1-encoding P. aeruginosa in early 2023. In the present study, we present the rapid reversal of the carbapenemase-producing P. aeruginosa epidemiology from blaVIM- to blaNDM-harbouring isolates that occurred in our hospital since then. Between January 2023 and February 2024, 139 isolates tested positive for carbapenemase production with the NG-Test CARBA 5 immunochromatographic assay. Eight isolates were processed with the Hybrispot antimicrobial resistance direct flow chip molecular assay, and the first NDM-producing isolate was further analyzed through whole genome sequencing and bioinformatics analysis. Multiple resistance genes were detected by molecular techniques in accordance with the extensively drug-resistant phenotype. The isolate that was subjected to whole-genome sequencing belonged to the P. aeruginosa high-risk clone ST308, and the blaNDM was located in the chromosome in accordance with previously reported data. During the study period, NDM-producing isolates were increasingly detected, and only five months after their emergence, they overcame VIM producers. Our results indicate the potential of this new clone to spread rapidly and predominate within healthcare institutions, further restricting the already limited treatment options.

In Vitro Synergistic Activity of Antimicrobial Combinations against Carbapenem- and Colistin-Resistant Acinetobacter baumannii and Klebsiella pneumoniae.

Polymyxins are commonly used as the last resort for the treatment of MDR Acinetobacter baumannii and Klebsiella pneumoniae nosocomial infections; however, apart from the already known toxicity issues, resistance to these agents is emerging. In the present study, we assessed the in vitro synergistic activity of antimicrobial combinations against carbapenem-resistant and colistin-resistant A. baumannii and K. pneumoniae in an effort to provide more options for their treatment. Two hundred A. baumannii and one hundred and six K. pneumoniae single clinical isolates with resistance to carbapenems and colistin, recovered between 1 January 2021 and 31 July 2022,were included. A. baumannii were tested by the MIC test strip fixed-ratio method for combinations of colistin with either meropenem or rifampicin or daptomycin. K. pneumoniae were tested for the combinations of colistin with meropenem and ceftazidime/avibactam with aztreonam. Synergy was observed at: 98.99% for colistin and meropenem against A. baumannii; 91.52% for colistin and rifampicin; and 100% for colistin and daptomycin. Synergy was also observed at: 73.56% for colistin and meropenem against K. pneumoniae and; and 93% for ceftazidime/avibactam with aztreonam. The tested antimicrobial combinations presented high synergy rates, rendering them valuable options against A. baumannii and K. pneumoniae infections.

Clinical Characteristics and Risk Factors for Bloodstream Infections in Children with Cancer: A Report from a Pediatric Hematology Oncology Unit.

BACKGROUND/AIM: Infections are a major cause of morbidity and mortality in children with haematologic malignancies and solid tumors as well as those undergoing hematopoietic stem cell transplantation (HSCT). The purpose of our study was to record the epidemiological characteristics and outcomes of bacteremias, focusing on pathogens, as well as risk factors and mortality rates in patients of a pediatric hematology-oncology unit from Northern Greece. MATERIALS AND METHODS: A retrospective analysis was conducted, which included all positive blood cultures from pediatric hematology oncology patients aged from 1 to 16 years old admitted to the Pediatric and Adolescent Hematology Oncology Unit of AHEPA University Hospital of Thessaloniki between January 2014 and December 2018. Data were collected from patients' printed and electronic medical records. RESULTS: 73 episodes of bacteremias were identified (41% male and 32% female with a ratio of 1.28:1; median age 6.5 years; 13.7% solid tumor, 72.6% acute lymphoblastic leukemia, 13.7% acute myeloid leukemia, and 95.8% with an indwelling permanent catheter). 49.3% of the isolates were Gram-positive bacteria and 50.7% Gram-negative, and the ratio of Gram-negative to Grampositive was 1.02. Coagulase-negative staphylococci were most frequent (39.7%), followed by E. coli (17.8%) and Klebsiella pneumoniae (17.8%). Out of all Gram-negatives, 13.5% carbapenemase producers and 8.1% ESBL-producers were found. In relation to Gram-positive, 79.3% were identified as methicillin-resistant CoNS. During the study period, 10.9% of indwelling catheters were removed, and 2.73% of episodes resulted in ICU transfer. The 3-month mortality rate was 8.2%. CONCLUSION: This study demonstrated an almost equal distribution of Gram-positive and Gramnegative bacteremias in total in this population but with an increase in the isolation of Grampositive bacteria over the last years, which is consistent with other similar studies in this patient group. Knowledge of the local epidemiology and bacterial antimicrobial resistance is important to prevent and timely treat these life-threatening infections in immunocompromised pediatric oncology patients.

Replacement of the Double Meropenem Disc Test with a Lateral Flow Assay for the Detection of Carbapenemase-Producing Enterobacterales and Pseudomonas aeruginosa in Clinical Laboratory Practice.

The prompt detection of carbapenemases among Gram-negative bacteria isolated from patients' clinical infection samples and surveillance cultures is important for the implementation of infection control measures. In this context, we evaluated the effectiveness of replacing phenotypic tests for the detection of carbapenemase producers with the immunochromatographic Carbapenem-Resistant K.N.I.V.O. Detection K-Set lateral flow assay (LFA). In total, 178 carbapenem-resistant Enterobacterales and 32 carbapenem-resistant Pseudomonas aeruginosa isolated in our hospital were tested with both our established phenotypic and molecular testing procedures and the LFA. The Kappa coefficient of agreement for Enterobacterales was 0.85 (p < 0.001) and 0.6 (p < 0.001) for P. aeruginosa. No major disagreements were observed and notably, in many cases, the LFA detected more carbapenemases than the double meropenem disc test, especially regarding OXA-48 in Enterobacterales and VIM in P. aeruginosa. Overall, the Carbapenem-Resistant K.N.I.V.O. Detection K-Set was very effective and at least equivalent to the standard procedures used in our lab. However, it was much faster as it provided results in 15 min compared to a minimum of 18-24 h for the phenotypic tests.