Moraxella species are fastidious Gram-negative bacteria capable of causing opportunistic infections, including bloodstream infections, especially in immunocompromised patients. Data on their epidemiology, antimicrobial susceptibility, and phylogenomics in Europe remains limited. We conducted a multicentre, retrospective, observational study across 56 European hospital centres between January 1st 2020 and December 31st 2024. All Moraxella species isolated from blood cultures (BCs) were included. Species distribution and antimicrobial susceptibility profiles were analysed. We also performed a phylogenomic analysis of Moraxella genomes deposited in GenBank. A total of 709 Moraxella isolates were included. Moraxella osloensis (61.1

BACKGROUND:Otitis is a very common infection, mainly affecting children, and the main indication for prescribing antibiotics. This study investigated the epidemiology and antibiotic resistance profile of bacterial pathogens asso-ciated with otitis in patients of all ages in Crete, Greece. METHODS:From January 2013 through December 2022, patients diagnosed with otitis, based on clinical signs and symptoms and otoscopy findings, were enrolled in the study. Ear discharge samples were collected by tympanοcentesis or by using sterile swabs and were promptly transported to the microbiology laboratory for further processing. Cultures for bacterial pathogens were performed according to laboratory protocols. Bacteria were identi-fied by matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry and antimicro-bial susceptibility testing by Vitek 2 system. RESULTS:Out of the 939 samples examined, 600 (63.9%) were positive for bacterial pathogens. P. aeruginosa was the most prevalent microorganism detected (29.5%), followed by S. aureus (18.9%) and Enterobacterales (12.8%). The isolation rate of P. aeruginosa significantly increased during the study period (p = 0.0001). P. aeruginosa resistance rates to ticarcillin/clavulanate, piperacillin/tazobactam, ceftazidime, cefepime, aztreonam, imipenem and meropenem were 6.4%, 3.4%, 3.4%, 3.8%, 3.3%, 2.1%, and 2.1%, respectively. Ceftazidime resistance remained around the same levels during the study period, while resistance to piperacillin/ tazobactam, cefepime, imipenem, and meropenem doubled over the years 2018 - 2022 (p = 0.48, p = 0.49, p = 0.65, and p = 0.65, respectively). S. aureus penicillin-resistance was extremely high (87.4%). Resistance rates to methicillin, erythromycin, and clindamycin were 21.2%, 14.6%, and 11.9%, respectively. Forty-one percent of the methicillin-resistant strains were multidrug-resistant (MDR). All isolates were susceptible to gentamicin, rifampicin, linezolid, daptomycin, tigecycline, teicoplanin, and vancomycin. Among Enterobacterales, high rates of resistance were observed for ampicillin, amoxicillin/ clavulanate, colistin, tigecycline, and tetracycline, ranging from 34.1% to 82.5%. CONCLUSIONS:P. aeruginosa, S. aureus, and the Enterobacterales are the predominant bacterial pathogens causing otitis in our area. Regarding Gram-negatives, although resistance rates to commonly-used antibiotics are low, they are increasing over time. Continued surveillance of the prevalence and antimicrobial susceptibility of bacterial pathogens causing otitis is necessary to reassess updated antimicrobial policies and develop appropriate guidelines.

Introduction Aeromonas species are Gram-negative bacilli capable of causing bloodstream infections in both immunocompromised and otherwise healthy individuals. However, data on their epidemiology and antimicrobial resistance remain limited in Europe. Methods We conducted a multicentre, retrospective, observational study that included all Aeromonas species isolates recovered from blood cultures in 56 European hospitals between January 1st 2020 and December 31st 2024. Epidemiological features and antimicrobial susceptibility profiles were analyzed. Results A total of 590 Aeromonas isolates were included. Most were recovered from polymicrobial blood cultures (73.1%), and catheter-related bloodstream infections were frequent (21.7%). The most commonly reported species were A. caviae (30.1%), isolates without conclusive species identification (Aeromonas spp., 24.8%), A. hydrophila (20.7%), and A. veronii (19.1%). At the genus level, susceptibility to aztreonam, ceftazidime, and cefepime exceeded 90%. Resistance to fluoroquinolones (∼10%) and sulfamethoxazole/trimethoprim (up to 11%) was observed. Species-level analyses showed higher resistance rates to fluoroquinolones and sulfamethoxazole/trimethoprim among A. caviae and A. hydrophila, and increased resistance to ceftazidime among Aeromonas spp. Conclusions Aeromonas species in Europe showed high susceptibility to ceftazidime and cefepime, alongside with emerging resistance to fluoroquinolones and sulfamethoxazole/trimethoprim. Species-specific findings should be interpreted cautiously due to limitations in routine identification methods, underscoring the need for sustained surveillance and harmonised diagnostic standards across Europe.

Nocardia species can cause serious infections, especially in immunocompromised individuals, though it can also affect immunocompetent patients. Bacteremia due to this organism is always clinically significant and is associated with high mortality rates. We reviewed all cases of Nocardia bacteremia published in medical literature since 2019. A total of 28 studies providing data for 29 patients were included. Among all patients, 69% were male; the median age was 60 years. Overall, 23 (79.3%) patients were immunosuppressed [immunosuppressive treatment (73.9%), malignancies (34.8%), transplantation (26.1%), and autoimmune diseases (26.1%)]. Pulmonary involvement was the most frequent concomitant site of infection. Fever, cough, dyspnea, shortness of breath, and fatigue were the most commonly encountered symptoms. Seven patients (24.1%) had concurrent infections at the time of Nocardia bacteremia. Most isolates were identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). N. farcinica was the most commonly identified species (44.8%), followed by N. cyricigeorgica (25%), and N. nova (10.3%). High rates of resistance were observed for amoxicillin/clavulanic acid and ciprofloxacin (57.1% for each), clindamycin (42.9%), cefotaxime (21.4%) and imipenem (21.4%). All 14 isolates tested for trimethoprim/sulfamethoxazole (TMP/SMX) and linezolid were susceptible. The median total duration of treatment was 7.2 months. TMP/SMX was used in 78.6% of patients, carbapenems in 60.7% and linezolid in 35.7%. Mortality rate was significant (34.5%). Nocardia bacteremia is a rare but serious disseminated form of nocardiosis. Early diagnosis and prompt aggressive treatment, typically with a combination of antibiotics and long-term therapy are crucial for improving outcomes.

Staphylococcal scalded skin syndrome (SSSS), caused by Staphylococcus aureus producing exfoliative toxins, develops in only a subset of colonized children, suggesting host genetic factors may influence disease susceptibility. Desmoglein-1 (DSG1), a key adhesion protein in the superficial epidermis, is the primary target of these exfoliative toxins. This study examined whether genetic variation in the DSG1 gene is associated with SSSS in children. We conducted a prospective case–control study of children aged 0–5 years, including patients diagnosed with SSSS and age-matched controls who either had non-SSSS S. aureus infections or were asymptomatic carriers, and whose isolates were PCR-confirmed to harbor at least one of the eta and/or etb toxin genes. Genotyping of the DSG1 rs12967407 single nucleotide polymorphism (SNP) was performed using PCR–RFLP. Eighty SSSS cases and forty controls were enrolled. The C/C genotype was significantly more common in cases than controls (43.8

OBJECTIVE:Kluyvera species are Gram-negative rods, catalase-positive, oxidase-negative, and glucose-fermenting members of the Enterobacteriaceae family. Although often considered saprophytic, Kluyvera can cause opportunistic infections, particularly in immunocompromised individuals, with severe underlying medical conditions. The objective of this study was to identify and evaluate all published cases of human infections by Kluyvera spp., through a systematic literature review. METHODS:We searched PubMed and Scopus databases for articles providing data related to the epidemiology, clinical features, and microbiology of Kluyvera human infections. RESULTS:In total, 73 studies provided information on 97 patients with Kluyvera infections. The mean age of the patients was 39.5 years and most (53.6%) were females. The most frequently reported types of infection were bacteremia, urinary tract infections, intra-abdominal infections, and soft tissue infections, and more than half of them were community-acquired. Comorbidities were common in majority of the patients, and almost half of these were immunosuppressed. K. ascorbata was the most commonly identified species (59.8%), followed by Kluyvera cryocrescens (23.7%), Kluyvera intermedia (3.1%), and Kluyvera georgiana (1.0%). High rates of resistance were recorded for ampicillin (78.1%), 1st-generation cephalosporins (52.1%), and 2nd-generation cephalosporins (43.8%). Third-generation cephalosporins were the most commonly used antibiotics, followed by aminoglycosides. The outcome was favorable for the majority of the patients (89.2%). The mortality rate attributed to the infection was 4.3%. CONCLUSION:Early detection of Kluyvera species is critical for effective infection control and antimicrobial stewardship, as these opportunistic pathogens are known to act as reservoirs for antibiotic resistance genes.

Rhodotorula species are basidiomycetous yeasts, commonly recognized as emerging opportunistic pathogens, particularly in immunocompromised patients. Fungemia is the most common presentation of Rhodotorula infections, which in the vast majority of cases is associated with the presence of central venous catheters (CVCs). This review evaluated all published documented cases of Rhodotorula fungemia between 2010 and 2025. We searched PubMed and Scopus databases for articles providing data related to the epidemiology, clinical features, microbiology, treatment and outcome of Rhodotorula fungemia over the past 16 years. A total of 32 studies involving 39 patients with Rhodotorula fungemia were identified. The mean patient age was 47.4 years and most (61.5%) were male. Comorbidities were common in 97.4% of the patients. Hematologic malignancies were the most frequent underlying condition. Use of CVCs, immunosuppressive therapy, use of broad-spectrum antibiotics, neutropenia and total parenteral nutrition were the main risk factors (56.4%, 51.3%, 66.7%, 40%, and 7.7%, respectively). Identification was most frequently performed using molecular methods (46.2%) and R. mucilaginosa was the predominant species (71.8%). Fever represented the most frequent clinical presentation (63.3%). Amphotericin B (AmB) and 5-flucytosine demonstrated good in vitro activity against Rhodotorula isolates. Treatment frequently involved administration of AmB, combined with catheter removal in those having CVCs. The mortality rate attributed to the infection was 10.3%. Rhodototula is an emerging but uncommon cause of non-Candida fungemia. Rapid and accurate identification of the yeast is critical to avoid inappropriate therapy. Early identification and prompt administration of tailored treatment are vital for improving patient outcomes.

INTRODUCTION:Non-fermenting Gram-negative bacilli (NFGNB) other than Pseudomonas and Acinetobacter species remain largely underrepresented in systematic surveillance programs across Europe. METHODS:We conducted a multicentre retrospective observational study analysing all minor NFGNB isolates recovered from blood cultures in 56 European Hospital Centres over a 5-year period (2020-2024). Diagnostic approach, epidemiology and antimicrobial susceptibility according to European Committee on Antimicrobial Susceptibility Testing v. 15.0 were investigated. RESULTS:A total of 4420 minor NFGNB isolates were included. In 43.6% of cases, the isolates were recovered from polymicrobial blood cultures, and 40.6% were detected during microbiologically defined catheter-related bloodstream infections. Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-ToF) mass spectrometry was the most widely used tool for species identification (98%). Antimicrobial susceptibility testing was conducted in all centres, using mostly broth microdilution commercial systems (57%), disk diffusion (57%) and gradient diffusion MIC strip (54%) methods, mainly according to European Committee on Antimicrobial Susceptibility Testing guidelines (67.9%). The most prevalent species were Stenotrophomonas maltophilia (52.4%), Achromobacter xylosoxidans (7.8%), Sphingomonas paucimobilis (5.3%) and the Burkholderia cepacia complex (4.8%). S. maltophilia displayed a high rate of resistance to sulfamethoxazole/trimethoprim (11%), and 2% of the isolates were found to be likely resistant to cefiderocol. A. xylosoxidans showed high resistance to meropenem (10%), piperacillin/tazobactam (24%) and sulfamethoxazole/trimethoprim (53%) when tested by MIC methods, while showing over 90% susceptibility to meropenem when tested by disk diffusion. S. paucimobilis displayed over 90% susceptibility to amoxicillin/clavulanate, ampicillin/sulbactam, imipenem, meropenem and tetracycline. CONCLUSIONS:This study provides an updated overview of the diagnostic approaches and epidemiology of minor NFGNB across Europe, supporting future comparative analyses and improved diagnostic and antimicrobial strategies.

BACKGROUND:The ESKAPE group (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter) is a major cause of life-threatening infections in Intensive Care Unit (ICU) critically ill patients accounting for significant morbidity and mortality. Management of infections by ESKAPE pathogens is complicated due to the remarkable rise in the rates of multidrug resistance (MDR) to most antimicrobial agents. This study investigated the trends of prevalence and antimicrobial resistance profiles of the ESKAPE pathogens isolated from clinical specimens of adult ICU patients. METHODS:All ESKAPE isolates collected from clinical specimens of ICU patients during the years 2013-2022 were processed according to routine methods. Identification of the bacterial isolates was performed by matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry and antimicrobial susceptibility testing by Vitek 2 system. RESULTS:During the ten-year period, a total of 6,132 ESKAPE strains were isolated from 5,338 samples of 1,792 ICU patients. A. baumannii was the most prevalent microorganism, followed by P. aeruginosa, and K. pneumoniae. High resistance to carbapenems was detected for A. baumannii (96.7 %) and K. pneumoniae (57.4 %). Methicillin-resistant were 39.1 % of S. aureus and vancomycin-resistant 38.7 % of the E. faecium isolates. MDR were characterized 39 % of K. pneumoniae and 13.1 % of P. aeruginosa strains, while 19.7 % of A. baumannii were pandrug resistant. CONCLUSIONS:An increased antimicrobial resistance among ESKAPE bacteria was found in our ICU setting. Enhanced antimicrobial surveillance, strict implementation of stewardship programmes and infection control practices are crucial to reduce AMR and develop management strategies to optimize outcomes.

BACKGROUND:Cedecea species are Gram-negative, facultative anaerobic, non-sporulating, catalase-positive, oxidase-negative and motile rod shaped bacteria belonging to Enterobacteriaceae family. Members of the genus Cedecea are rarely reported to cause human infections. These infections primarily occur in immunocompromised patients with severe underlying medical conditions. The objective of this review was to collect and evaluate all published documented cases of Cedecea spp. human infections. METHODS:We searched PubMed and Scopus databases for articles providing data related to the epidemiology, clinical features and microbiology of Cedecea human infections. RESULTS:A total of 49 studies involving 50 patients with Cedecea infections were regarded as eligible for inclusion in our review. The mean patient age was 53.3 years and most (72 %) were male. Comorbidities were common in 88 % of the patients. The most common types of infection were bacteremia, respiratory tract infections, soft tissue infections and urinary tract infections, and more than half of them were healthcare-associated. C. lapagei was the predominant species, followed by C. davisae and C. neteri. High rates of resistance were recorded for ampicillin (47.6 %), gentamicin (38.1 %), amoxicillin-clavulanate, cephalothin, and ceftazidime (33.3 %) each. Ciprofloxacin was the most frequently used antibiotic, followed by meropenem. The median treatment duration was 14 days. The outcome was favorable for the majority of the patients (87.8 %). The mortality rate attributed to the infection was 10.2 %. CONCLUSIONS:Physicians should be aware of this rare pathogen that exhibits resistance to many antibiotics, so they can tailor antimicrobial treatment based on susceptibility testing results to optimize outcome.

Infections caused by anaerobes are common in children. However, limited data are available on bloodstream infections caused by these bacteria in Europe. A multicentre retrospective observational study was conducted over a 4-year period (2020-2023) across 44 European hospitals to analyze all anaerobes isolated from blood cultures. The study examined the epidemiology and antimicrobial resistance profiles of anaerobes identified in paediatric patients, comparing the findings with those observed in adults. Among the 14,527 total anaerobic isolates, 186 (1.3%) were detected from paediatric patients. These were predominantly Gram-positive (70%) and Gram-negative (22%) bacilli. The most prevalent species in paediatric patients were Cutibacterium acnes (24.7%), Schaalia odontolytica (9.7%), Actinomyces oris (8.1%), and Bacteroides fragilis (7.5%). Relative feature importance based on the mean SHAP (SHapley Additive exPlanations) values distinguished paediatric patients and adults based on their antibiotic resistance patterns with high accuracy. Compared to those from adult patients, Gram-positive bacilli detected in paediatric samples displayed higher resistance rates for meropenem (15% vs. 9%), metronidazole (52% vs. 24%), and vancomycin (27% vs. 6%), and lower resistance to benzylpenicillin (11% vs. 17%), amoxicillin/clavulanate (9% vs. 17%), and clindamycin (30% vs. 36%). Gram-negative bacilli in paediatric samples displayed lower resistance to benzylpenicillin (18% vs. 29%), piperacillin/tazobactam (26% vs. 33%), and clindamycin (20% vs. 27%), and they were highly susceptible to imipenem, meropenem, and metronidazole as those detected in adult patients. Bacteroides species detected in paediatric and adult patients displayed high resistance to piperacillin/tazobactam (33% vs. 39%) and clindamycin (38% vs. 29%), while they were highly susceptible to metronidazole. Compared to those from adult samples, Cutibacterium acnes in paediatric patients displayed lower resistance to benzylpenicillin (none vs. 15%) and clindamycin (17% vs. 29%). The comparison of species and susceptibility profiles of anaerobes detected in paediatric and adult patients highlighted the importance of reporting antimicrobial susceptibility surveillance data by age group.

Introduction: Despite being implicated in a wide spectrum of community-and healthcare-acquired infections, anaerobes have not yet been incorporated into systematic surveillance programs in Europe. Methods: We conducted a multicentre retrospective observational study analysing all anaerobic strains isolated from blood cultures in 44 European Hospital Centres over a 4-y period (2020-2023). Diagnostic approach, epidemiology, and antimicrobial susceptibility according to EUCAST v. 15.0 were investigated. Results: Our study included 14,527 anaerobes, most of which were Gram-positive (45%) or Gram-negative (40%) bacilli. MALDI-TOF coupled to mass spectrometry was the most widely used tool for species identification (98%). Antimicrobial susceptibility testing was performed in the vast majority of centres, using mostly gradient diffusion strip (77%) and disk diffusion (45%) methods according to EUCAST guidelines. The most prevalent species were Cutibacterium acnes (18.7%), Bacteroides fragilis (16.3%), Clostridium perfringens (5.3%), Bacteroides thetaiotaomicron (4.2%), Fusobacterium nucleatum (3.5%), and Parvimonas micra (3.4%). C. acnes showed high resistance to benzylpenicillin (18%), clindamycin (39%), and imipenem (19% and 13% by MIC methods and disk diffusion, respectively). B. fragilis showed high resistance to amoxicillin/clavulanate (24%), piperacillin/tazobactam (22% and 14% by MIC methods and disk diffusion, respectively), clindamycin (22% by both MIC methods and disk diffusion), meropenem (13%), and metronidazole (10%, only by disk diffusion). A similar resistance pattern was observed in B. thetaiotaomicron, Bacteroides ovatus, and Parabacteroides distasonis. C. perfringens showed high resistance to clindamycin (69% and 45% by MIC methods and disk diffusion, respectively), while benzylpenicillin and metronidazole maintained over 90% activity. F. nucleatum showed high resistance to benzylpenicillin (11%), while Fusobacterium necrophorum showed alarming rates of resistance to clindamycin (12%), meropenem (16%) and metronidazole (11%). Conclusions: This study presented an up-to-date analysis of the diagnostics and epidemiology of anaerobic bacteria in Europe, providing insights for future comparative analyses and the development of antimicrobial diagnostic and management strategies, as well as the optimization of current antibiotic treatments. (c) 2025 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)

BACKGROUND:Group B Streptococcus (GBS) infection remains a significant cause of neonatal morbidity and mortality worldwide. Universal screening using rectovaginal swabs and intrapartum antibiotic prophylaxis for GBS-positive women is a standard practice to prevent early-onset neonatal disease. Colonization rates vary internationally, and comprehensive data from Greece are limited. This study aimed to evaluate the incidence of GBS colonization and associated risk factors among pregnant women in Crete, Greece. METHODS:This retrospective study included all pregnant women and their newborns admitted to two major hospitals in Crete between January 1, 2015, and December 31, 2019. GBS colonization was assessed via vaginal cultures. Data on maternal age, nationality, area of residence, multiparity, comorbidities (e.g., diabetes, hypertension), number of prenatal visits, gestational age at screening, and mode of delivery were analyzed. Rates of antibiotic prophylaxis and incidence of neonatal GBS disease were also reviewed. RESULTS:Out of 7362 pregnant women reviewed, 4984 (67.7 %) underwent GBS screening. GBS colonization was found in 83 women (1.7 %). The highest colonization rate was among women aged 31-35 years (34.9 %). Screening before the 35th gestational week occurred in 45.8 % of cases, and comorbidities such as diabetes or hypertension were present in 9.6 %. Multiparity (≥2 births) was significantly associated with colonization (66.3 %), while other factors showed no significant association. All identified GBS-positive women received intrapartum antibiotic prophylaxis, and no cases of neonatal GBS disease were observed. CONCLUSIONS:The GBS colonization rate in Crete is among the lowest globally reported. Universal screening combined with intrapartum antibiotic prophylaxis effectively prevented neonatal GBS disease. The establishment of clear national guidelines is crucial to ensure consistent screening practices and responsible antibiotic stewardship.

Background/Objectives: Methicillin-resistant Staphylococcus aureus (MRSA) poses significant treatment challenges, particularly in community settings. Limited data are available on S. aureus-associated infected dermatoses (ID) in outpatient dermatology clinics. This study examines the clinical characteristics, microbiological profiles, resistance patterns, and treatment outcomes of dermatoses caused by S. aureus. Methods: Between January 2023 and January 2025, consecutive patients with confirmed S. aureus-associated SD were recruited in a dermatology clinic in Heraklion, Greece. Demographic, clinical, and treatment data were collected. Skin swabs underwent bacterial culture and antimicrobial susceptibility testing following CLSI guidelines. Statistical analyses evaluated associations between clinical and microbiological findings. Results: Sixty-eight patients were included, 54.4% of whom were male, with a mean age of 46.7 years (± SD 25.1). MRSA was identified in 22.1% of cases and was significantly associated with female gender (p = 0.014). The most common diagnoses were eczema (35.3%) and folliculitis (19.1%). Oxacillin-resistant patients were more likely to receive systemic therapy (p = 0.039). Resistance rates were highest for benzylpenicillin (81.8%), levofloxacin (54.9%), and erythromycin (39.4%). Resistance rates for fusidic acid, clindamycin, mupirocin, and tetracycline were 38.2%, 20.6%, 16.9%, and 10.3%, respectively. Other pathogens, including Pseudomonas aeruginosa and Escherichia coli, were isolated in 27.9% of cases. Conclusions: This study highlights the high prevalence of MRSA in outpatient dermatology settings, emphasizing the need for local antimicrobial resistance surveillance to guide treatment strategies and improve outcomes in superinfected dermatoses.

Turicella otitidis is a Gram-positive bacillus, commensal inhabitant of the external auditory canal. It is the causative agent of external otitis and otitis media. Extra-otic infections are rarely been identified especially in patients with comorbidities. A narrative review was performed based on a search of PubMed/Medline and Scopus databases to collect information on the epidemiologic, clinical and microbiologic data of extra-otic infections by T. otitidis . Studies published until December 2024 were screened and analyzed to extract data on pathogen characteristics, antibiotic resistance profiles, treatment and outcomes. A total of 13 studies reporting infections by T. otitidis other than otitis including an equal number of patients were eligible. The mean age of patients was 34.08 years (range, 3-75 years). A male predominance was observed (1.6:1). Four patients were immunocompromised and four underwent recent surgical procedures. The most common infection type was bacteremia (38.4%), followed by abscesses, mastoiditis, ocular infections and skin and soft tissues infections. In the majority of cases (63.6%) a single method of identification was applied, such as matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS), polymerase chain reaction (PCR), Vitek 2 automated system and analytical profile index (API) Coryne. Antimicrobial resistance to erythromycin was 80%, while all isolates were susceptible to vancomycin. Vancomycin (45.5%) and cephalosporins (45.5%) were the most commonly used antimicrobials. In all cases with available data, the outcome was favorable. T. otitidis is an emerging pathogen causing extra-otic infections in humans, especially in the presence of predisposing conditions. Future studies are warranted to elucidate the microorganism's pathogenicity and the factors and mechanisms underlying its virulence.

Objective: Clostridioides difficile is a major cause of healthcare-associated diarrhea worldwide. For years, metronidazole and vancomycin were considered the standard treatment for C. difficile infection. However, they are increasingly being associated with treatment failure and recurrence. In this study, we investigated the in vitro activity of dalbavancin and fourteen other antimicrobials against 155 toxigenic C. difficile isolates originating from patients with C. difficile-associated diarrhea. Materials and Methods: Antimicrobial susceptibility was evaluated by the MIC Test Strip, and the results were interpreted using both the Clinical and Laboratory Standards Institute (CLSI) and the European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints. Results: C. difficile isolates were fully susceptible to metronidazole, vancomycin, amoxicillin/clavulanate, piperacillin/tazobactam, and tigecycline. All isolates were dalbavancin susceptible by the CLSI breakpoint (≤0.25 μg/mL) compared with 97.4% susceptibility by the EUCAST breakpoint (≤0.125 μg/mL). Dalbavancin demonstrated significantly lower MIC50 and MIC90 values compared to vancomycin (0.047 vs. 0.38 and 0.125 vs. 0.5, respectively, p < 0.001). Resistance rates to penicillin, ampicillin, cefoxitin, imipenem, meropenem, clindamycin, moxifloxacin, chloramphenicol, and tetracycline were 20%, 14.2%, 100%, 75.5%, 0.6%, 51%, 36.1%, 3.2%, and 14.8%, respectively. Multidrug-resistant phenotypes were detected among 41.3% of the isolates. Conclusion: Dalbavancin exhibited potent activity against the isolates tested. As C. difficile is an important healthcare-associated pathogen, continued surveillance is required to monitor for development of resistance.

BACKGROUND:Pseudomonas aeruginosa (PA) bloodstream infection (BSI) is a common healthcare-associated complication linked to antimicrobial resistance and high mortality. Ongoing clinical trials are exploring novel anti-virulence agents, yet studies on how bacterial virulence affects PA infection outcomes is conflicting and data from real-world clinical populations is limited. METHODS:We studied a multicentre cohort of 773 adult patients with PA BSI consecutively collected during 7-years from sites in Europe and Australia. Comprehensive clinical data and whole-genome sequencing of all bacterial strains were obtained. RESULTS:Based on the virulence genotype, we identify several virulence clusters, each showing varying proportions of multidrug-resistant phenotypes. Genes tied to biofilm synthesis and epidemic clones ST175 and ST235 are associated with mortality, while the type III secretion system is associated with septic shock. Adding genomic biomarkers to machine learning models based on clinical data indicates improved prediction of severe outcomes in PA BSI patients. CONCLUSIONS:These findings suggest that virulence markers provide prognostic information with potential applications in guiding adjuvant sepsis treatments.

BACKGROUND:Pneumococcal disease is still considered a global problem. With the introduction of pneumococcal conjugate vaccines (PCVs) serotype epidemiology changed, but antimicrobial resistance persists constituting a serious problem. The current study aimed to determine the serotype distribution and the antimicrobial susceptibility of recent Streptococcus pneumoniae isolates, following implementation of the 13-valent conjugate vaccine (PCV13). MATERIALS AND METHODS:From January 2017 to December 2022 we evaluated 116 nonduplicate S. pneumoniae isolates collected from adult patients (21 - 98 years) cared for in the University Hospital of Heraklion, Crete, Greece. Pneumococcal isolates were serotyped by the Quellung reaction, and antimicrobial susceptibility testing was performed using E-test. Multidrug resistance (MDR) was defined as non-susceptibility to at least one agent in ≥3 classes of antibiotics. RESULTS:Among the 116 isolates, 31% were recognized as invasive pneumococcal strains, while 69% were non-invasive. The isolates tested belonged to 25 different serotypes. The most prevalent serotypes were 11A (10.3%), and 35B (10.3%), followed by 3 (9.5%), 15A (7.8%), 25F (6.9%), 19A (5.3%), 35F (5.3%), and others (44.6%). The coverage rates of PCV13 and the pneumococcal polysaccharide vaccine (PPSV23) were 26.7% and 57.8%, respectively. PCV13 and PPSV23 serotypes decreased between 2017 - 2019 and 2020 - 2022, with a parallel increase in the non-vaccine types. Resistance rates to erythromycin, clindamycin, trimethoprim/sulfamethoxazole, penicillin, levofloxacin, and ceftriaxone, were 40.5%, 21.6%, 13.8%, 12.1%, 3.4%, and 0%, respectively. All isolates were susceptible to vancomycin, linezolid, and daptomycin. MDR was observed among 36 (31%) S. pneumoniae isolates. CONCLUSION:The increasing levels of resistance in S. pneumoniae in Crete, Greece, highlight the need for continuous surveillance of antimicrobial resistance and development of strategies for its reduction, including antimicrobial stewardship programs, increased pneumococcal vaccination, and development of next generation PCVs with a wider serotype coverage.

Elizabethkingia anophelis is an opportunistic pathogen causing lifethreatening infections in humans, particularly in immunocompromised patients, neonates and the elderly. We report a case of central line-associated bloodstream infection by E. anophelis in a 2.5-year-old girl with acute lymphoblastic leukemia successfully treated with a combination of piperacillin/tazobactam and amikacin. The literature was also reviewed on pediatric infections caused by E. anophelis, focusing on clinical manifestations, underlying medical conditions, treatment and outcome. Accurate identification with MALDI-TOF, or using molecular techniques, is of the utmost importance because treatment and prognosis differ depending on the species. Considering that E. anophelis is multiresistant to antibiotics and that inappropriate antimicrobial therapy is an independent risk factor for mortality, the early, accurate identification of bacterial species and prompt effective treatment are essential to achieve optimal therapeutic outcomes.