Background: Antimicrobial resistance (AMR) is an escalating global health threat, projected to cause over 40 million deaths by 2050. ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) are major contributors to nosocomial infections and AMR. We evaluated the epidemiology and AMR prevalence of ESKAPE pathogens at the University Hospital in Palermo between January 2018 and July 2023, analyzing factors associated with mortality in patients with positive blood cultures. Methods: Microbiological data from all specimen types were collected using the Business Intelligence system Biwer, excluding duplicates. We assessed the prevalence and trends of ESKAPE isolates and AMR over time. Clinical data from hospital discharge forms were used to evaluate factors associated with mortality in patients with ESKAPE-positive blood cultures. Differences in AMR prevalence between blood and non-blood isolates were examined. Results: A total of 11,607 specimens from 4916 patients were analyzed. Most patients were admitted to Internal Medicine (19.4%), the ICU (13.2%), and General Surgery (9.9%). Additionally, 21.5% of the specimens were collected from ICU-admitted patients. Blood cultures accounted for 14.3% of the specimens, urine for 25.3%, respiratory secretions for 22.1%, and skin and mucosal swabs for 20.9%. The prevalence of all isolates increased progressively, peaking in 2021. The vancomycin-resistant E. faecium prevalence was 19.4%, with a significant upward trend, while oxacillin-resistant S. aureus prevalence was 35.0%, showing a significant decline. A. baumannii exhibited high resistance to all antibiotics tested except for colistin and cefiderocol. Carbapenemase resistance was 55.0% in K. pneumoniae, 20.4% in P. aeruginosa, and 4.6% in Enterobacter spp. P. aeruginosa showed a significant decrease in meropenem resistance. K. pneumoniae and A. baumannii bloodstream infections were linked to higher mortality risk.

Background: Bloodstream infections (BSIs) are both a primary cause and a severe complication of hospitalization. This retrospective study aims to analyze the epidemiology of BSIs at the University Hospital of Palermo from 2018 to 2024. Methods: We conducted a single-center, retrospective, observational study at the University Hospital Paolo Giaccone in Palermo, analyzing microbiological data from blood cultures collected between 1 January 2018 and 31 December 2024. Results: A total of 6345 blood culture isolates from 2967 patients were analyzed. Bacteremia-related mortality per 1000 patients rose from 5.1% in 2018 to 10.5% in 2024. The most isolated pathogens were non-aureus staphylococci (39.7%), followed by Klebsiella pneumoniae (12.1%) and Staphylococcus aureus (7.47%). Acinetobacter baumannii and Pseudomonas aeruginosa were more prevalent in ICUs. The number of K. pneumoniae, A. baumannii, S. aureus, and P. aeruginosa isolates per 1000 admitted patients increased significantly over time. Oxacillin resistance in S. aureus peaked at 49.0% in 2020 before declining, while among non-aureus staphylococci, it remained consistently high (>80%). Carbapenem-resistant K. pneumoniae peaked at 80% in 2022 before decreasing in 2024. Resistance to ceftazidime-avibactam and meropenem-vaborbactam was observed in 11.3% and 11.8% of K. pneumoniae, respectively. Multivariable analysis identified A. baumannii and K. pneumoniae BSIs as independent predictors of in-hospital mortality. Additionally, female sex, pneumonia, and central nervous system infections were significant risk factors for mortality. Conclusions: We observed an increasing trend in overall bacteremia-related mortality from 2018 to 2024. Microbiological data highlight the predominance of non-aureus staphylococci, K. pneumoniae, and S. aureus as leading pathogens of BSI, with A. baumannii emerging as a significant threat, particularly in ICUs. Rising antimicrobial resistance, especially among K. pneumoniae, underscores the urgent need for robust antimicrobial stewardship programs. K. pneumoniae and A. baumannii were associated with higher mortality.

Background: Syphilis can present with diverse clinical manifestations, earning the name “great imitator.” Malignant syphilis (MS) is a rare, severe form of secondary syphilis, typically reported in immunocompromised patients, particularly those living with HIV. However, MS can occasionally occur in immunocompetent individuals, posing diagnostic challenges due to its atypical presentation. Methods: A case report is presented alongside a PubMed literature search using the terms “(malignant syphilis OR lues maligna) AND (immunocompetent) AND (case report OR case series).” No language or temporal restrictions were applied, yielding 18 relevant publications. Results: A 60-year-old HIV-negative man presented with fever, weight loss, papular lesions, and a single ulcer on the sternum. Serology was positive for syphilis, and PCR confirmed T. pallidum DNA in the lesion. Treatment with a single intramuscular dose of benzathine penicillin G led to prompt clinical and serological improvement. Literature review (n = 18) showed that MS in immunocompetent patients affects both sexes (55% male; mean age 37.1 years), often presents with ulceronodular or rupioid crusted lesions, and frequently involves systemic symptoms. Molecular diagnostics were rarely reported, with most diagnoses relying on histopathology and serology. Treatment with benzathine penicillin G was effective in all cases, and full recovery was achieved. Conclusions: MS can occur in immunocompetent, HIV-negative individuals without obvious risk factors. Clinicians should maintain a high index of suspicion in cases of systemic, cutaneous, or ocular manifestations suggestive of MS. Molecular assays can facilitate diagnosis and prevent unnecessary invasive procedures. Benzathine penicillin G remains the treatment of choice, demonstrating high therapeutic effectiveness. MS should be considered in the differential diagnosis of ulcerative or nodular dermatoses, regardless of immune status.

Background: Carbapenem-resistant Klebsiella pneumoniae (CRKP) poses a significant therapeutic challenge, particularly when multiple resistance mechanisms, such as metallo-β-lactamases (MBLs) and Klebsiella pneumoniae carbapenemase (KPC), coexist. Case description: We describe a case of a 51-year-old male with a post-sternotomy surgical site infection and concurrent bacteremia caused by a CRKP. Sternal swab and mediastinal liquid culture results highlighted CRKP harboring bla_NDM and bla_KPC genes, while the blood isolate showed bla_CTX and bla_KPC, indicating phenotypic resistance to ceftazidime-avibactam. All the strains exhibited phenotypic susceptibility to meropenem-vaborbactam (MEV), despite having a high minimum inhibitory concentration. Following clinical failure of MEV-based therapy, combination treatment with aztreonam (ATM) and imipenem/cilastatin/relebactam (IMI/REL), plus gentamicin, was initiated. Therapy was well tolerated and resulted in microbiological eradication and full clinical recovery. The patient completed 49 days of ATM and IMI/REL without relapse over a 3-month follow-up period. This is, to the best of our knowledge, the first reported case of IMI/REL being used in combination with ATM.

Background: Human metapneumovirus (HMPV) is a significant cause of respiratory infections, particularly in children, the elderly, and immunocompromised individuals. However, data on HMPV infection in people living with HIV (PLWH) are limited, and cases of co-infection with influenza A virus in this population have not been previously described. Case Presentation: We reported the case of a 73-year-old HIV-positive man with multiple comorbidities, including insulin-dependent diabetes mellitus, who presented with fever, asthenia, and glycometabolic decompensation. Despite an initially unremarkable chest computed tomography (CT) scan, the patient developed progressive respiratory failure, requiring high-flow oxygen therapy. Molecular testing using the BIOFIRE^® FILMARRAY^® Pneumonia Panel Plus identified HMPV and influenza A virus as the causative pathogens. Bacterial cultures were negative, allowing for the discontinuation of empirical antibiotic therapy. The patient was successfully weaned off oxygen therapy and discharged after clinical improvement. Conclusions: This case highlights the potential severity of HMPV and influenza A co-infection in PLWH, emphasizing the importance of molecular diagnostics in distinguishing viral from bacterial infections. Rapid and accurate pathogen identification is essential for guiding appropriate antimicrobial stewardship and optimizing patient outcomes in community-acquired pneumonia.

Background: Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has emerged as a genetically distinct lineage from healthcare-associated MRSA (HA-MRSA), often producing Panton-Valentine leukocidin (PVL) and causing severe skin and soft tissue infections (SSTIs) in otherwise healthy individuals. Methods: We describe five cases of PVL-positive CA-MRSA SSTIs admitted to the Infectious Diseases Unit of the University Hospital “Paolo Giaccone,” Palermo, Italy, between 2024 and 2025. Case inclusion followed the CDC criteria for CA-MRSA. Microbiological identification was performed using MALDI-TOF mass spectrometry, and antimicrobial susceptibility testing followed EUCAST standards. PVL gene presence was confirmed by polymerase chain reaction. Results: Clinical management included surgical drainage, systemic antibiotic therapy, and decolonization of both patients and close contacts. Long-acting lipoglycopeptides (oritavancin or dalbavancin) were evaluated as therapeutic options to achieve clinical resolution. Conclusions: PVL-positive CA-MRSA infections are characterized by recurrence, intrafamilial clustering, and frequent therapeutic failure with standard oral agents. Effective management requires an integrated approach combining prompt surgical drainage; systemic therapy, preferably including long-acting lipoglycopeptides; and comprehensive decolonization of all close contacts.