Clostridioides difficile infection (CDI) is a significant cause of morbidity and mortality, mostly in frail patients. Notification is not mandatory in Italy, and data on incidence, risk of death, and recurrence are lacking. The purpose of this study was to determine CDI incidence and risk factors for mortality and recurrence. The “ICD-9 00845” code in hospital-standardized discharged forms (H-SDF) and microbiology datasets were used to retrieve CDI cases at Policlinico Hospital, Palermo between 2013 and 2022. Incidence, ward distribution, recurrence rate, mortality, and coding rate were considered. The risk of death and recurrence was predicted through multivariable analysis. There were 275 CDIs, 75% hospital-acquired, the median time between admission and diagnosis was 13 days, and the median stay was 21 days. Incidence increased from 0.3 to 5.6% (an 18.7-fold increase) throughout the decade. Only 48.1% of cases were coded in H-SDF. The rate of severe/severe-complicated cases increased 1.9 times. Fidaxomicin was used in 17.1% and 24.7% of cases overall and since 2019. Overall and attributable mortalities were 11.3% and 4.7%, respectively. Median time between diagnosis and death was 11 days, and recurrence rate was 4%. Bezlotoxumab was administered in 64% of recurrences. Multivariable analysis revealed that only hemodialysis was associated with mortality. No statistically significant association in predicting recurrence risk emerged. We advocate for CDI notification to become mandatory and recommend coding CDI diagnosis in H-SDF to aid in infection rate monitoring. Maximum attention should be paid to preventing people on hemodialysis from getting CDI.

Background: Clostridioides difficile infection (CDI) remains a challenging condition, particularly in severe or recurrent cases. This study aimed to identify factors associated with recurrent CDI (rCDI), severe disease (defined by ZAR score or ESCMID criteria), death during CDI, and bloodstream infections (BSI) or candidemia within 8 weeks of CDI onset. Methods: We conducted a prospective study at an Italian university hospital that included all adult CDI cases diagnosed between November 2022 and December 2024. Statistical analyses were performed with IBM SPSS Statistics. A p-value < 0.05 was considered statistically significant in univariate analyses. For the multivariable analysis, we selected the variables that were statistically significant in the univariate analysis and considered the most clinically relevant. Results: A total of 161 CDI cases were identified. Recurrence occurred in 13%, higher than the 4% reported in a previous retrospective cohort at the same center (2013–2022). In univariate analysis, independent predictors of recurrent CDI (rCDI) were therapeutic regimens including oral vancomycin (p = 0.008; OR 6.17; 95% CI 1.36–27.97), peripheral vascular disease (PVD) (p < 0.001; OR 5.92; 95% CI 2.07–16.94), and dysphagia (p = 0.034; OR 4.61; 95% CI 1.25–17.07), whereas fidaxomicin use was associated with a protective effect (p = 0.016; OR 0.17; 95% CI 0.04–0.78). In multivariable analysis, oral vancomycin use (p = 0.008; OR 15.03) and peripheral vascular disease (p = 0.002; OR 7.27) remained independently associated with rCDI. Overall, 15 of 161 patients (9.3%) died during the CDI episode (either presenting CDI or rCDI), with all deaths directly attributable to CDI. Mortality during CDI was associated with age > 77 years (median value of the study population), transfer from a nursing home or long-term care facility within the previous 3 months, lymphoma, hematological malignancy, peripheral vascular disease, connective tissue disease, immobilization syndrome, dysphagia, elevated lactate levels (>1 mmol/L), septic shock, severe or severe-complicated CDI according to ESCMID criteria, severe-complicated CDI according to ESCMID criteria, leukocytosis (WBC > 15,000/mm³) during CDI, ZAR score ≥ 2, concomitant BSI, and concomitant pneumonia. During follow-up, 11 of 127 (8.7%) patients developed a BSI. BSI was associated with corticosteroid use and osteomyelitis. Only four patients developed candidemia due to Candida albicans during follow-up. Conclusions: Our study confirms that Clostridioides difficile infection remains a major clinical challenge, particularly due to its high recurrence rate and the burden of severe forms. The evidence strongly supports the preferential use of fidaxomicin, which should now be regarded as the standard of reference in clinical practice.

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: Rapid antimicrobial susceptibility testing (RAST) allows early detection of resistance directly from positive blood cultures, potentially improving outcomes in bloodstream infections (BSIs). We evaluated the performance of EUCAST RAST for Gram-negative ESKAPEEc pathogens and characterized carbapenemase genes in carbapenem-resistant Klebsiella pneumoniae (CRKP). Methods: A total of 354 positive blood cultures were screened, including 51 monomicrobial Gram-negative ESKAPEEc isolates. RAST results at 4, 6, 8, and 16–20 h were compared with standard antimicrobial susceptibility testing (AST) obtained using the BD Phoenix™ system. Categorical agreement (CA) and error frequency were calculated. Multiplex PCR and Sanger sequencing were performed on 15 CRKP isolates to identify carbapenemase genes and allelic variants. Results: 51 Gram-negative ESKAPEEc isolates met the inclusion criteria for RAST (15 E. coli, 19 K. pneumoniae, 11 A. baumannii, and 6 P. aeruginosa). Overall performance varied markedly by species and antibiotic. E. coli showed frequent unreadable or ATU zones at early timepoints and wide CA variability (50–100%), with high very major error (VME) rates for AMP, TZP, and CAZ, particularly at 6–8 h. K. pneumoniae displayed consistently high CA (mostly 100%) for carbapenems, CAZ, and TZP. A. baumannii demonstrated excellent agreement (100% for most agents), except for GEN at 6–8 h. P. aeruginosa could be evaluated only at 16–20 h, showing high CA for AMK, CAZ, and CIP; lower CA for MEM (83%); non-calculable CA for IMI due to universal ATU readings; and a CA value of 0% for TZP due to the predominance of the ATU results. VMEs ranged from 0% to 26.1% across species and reading times, but carbapenems did not generate VMEs. Molecular analysis revealed bla_KPC in 66.7%, bla_NDM in 46.7%, and bla_OXA-48 in 33.3% of isolates, with co-occurrence in several strains. Sequencing identified bla_KPC-2 and bla_NDM-1 as the predominant variants, with one isolate harboring bla_NDM-5. Conclusions: EUCAST RAST markedly accelerates susceptibility reporting from positive blood cultures, but its accuracy is species- and time-dependent. Performance was excellent for K. pneumoniae (including CRKP) and A. baumannii and acceptable for P. aeruginosa at 16–20 h. In contrast, E. coli showed frequent ATU results at early timepoints and high ME/VME rates, making readings before 8 h unreliable for clinical decisions. Overall, RAST can effectively support rapid antimicrobial stewardship when species-specific limitations are recognized, and early-timepoint results are interpreted with caution.

Human subcutaneous dirofilariasis caused by Dirofilaria repens is an emerging zoonotic parasitic infection increasingly observed in southern Europe. We report a case of a woman from western Sicily, who likely acquired the infection locally through a mosquito bite. The high prevalence of D. repens in the local canine population (up to 20.4%) suggests a role of dogs as a probable reservoir for transmission to humans in the local population. With ultrasound analysis being inconclusive, only after surgical removal was the presence of an adult worm evident, and only after molecular analysis through DNA sequencing of the cytochrome oxidase subunit I gene (COI) could a definitive D. repens infection diagnosis be obtained. This case highlights the need for enhanced vector control, animal health surveillance and public awareness to limit the transmission to humans of D. repens. A correct parasitological diagnosis would be imperative for the recognition of human cases.