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Background/objectives: ESKAPE pathogens ( Enterococcus faecium , Staphylococcus aureus , Klebsiella pneumoniae , Acinetobacter baumannii , Pseudomonas aeruginosa , and Enterobacter spp.) pose a serious public health threat as they are resistant to multiple antimicrobial agents. Bloodstream infections (BSIs) caused by ESKAPE bacteria have high mortality rates due to the limited availability of effective antimicrobials. This study aimed to evaluate the prevalence and susceptibility of ESKAPE pathogens causing BSIs over three years in a large tertiary hospital in Salerno., Methods: Conducted at the Clinical Microbiology Laboratory of San Giovanni di Dio e ''Ruggi D'Aragona'' Hospital from January 2020 to December 2022, blood culture samples from different departments were incubated in the BD BACTEC™ system for 5 days. Species identification was performed using MALDI-TOF MS, and antimicrobial resistance patterns were determined by the VITEK2 system., Results: Out of 3197 species isolated from positive blood cultures, 38.7% were ESKAPE bacteria. Of these, 59.9% were found in blood culture samples taken from men, and the most affected age group was those aged >60 years. (70.6%). Staphylococcus aureus was the main BSI pathogen (26.3%), followed by Klebsiella pneumoniae (15.8%). Significant resistance rates were found, including 35% of Staphylococcus aureus being resistant to oxacillin and over 90% of Acinetobacter baumannii being resistant to carbapenems., Conclusions: These results highlight the urgent need for antimicrobial stewardship programs to prevent incurable infections.

The spread of antibiotic resistance represents a serious worldwide public health issue, underscoring the importance of epidemiology research in determining antimicrobial strategies. The purpose of this research was to investigate antibiotic resistance in Serratia marcescens isolates from clinical samples over seven years at the University Hospital "San Giovanni di Dio e Ruggi d'Aragona" in Salerno, Italy. S. marcescens is an important opportunistic pathogen associated with a wide spectrum of clinical diseases, including pneumonia, keratitis, meningitis, and urinary tract and wound infections. Outbreaks of nosocomial infections by S. marcescens strains have been documented in high-risk settings, mainly affecting immunocompromised patients and newborns. The primary objective of this study is to assess the rates of antibiotic resistance over the years to deal with a future emergency which includes the failure of various therapies due to antibiotic resistance. During the investigation, a total of 396 species of S. marcescens were isolated from various clinical samples, mainly from broncho-aspirates and sputum (31.6%) and blood cultures (21.5%). Antibiotics that showed the greatest susceptibility included ceftazidime/avibactam, amikacin, trimethoprim/sulfamethoxazole, and selected members of the cephalosporin class. However, a disconcerting trend of increasing rates of carbapenem resistance was outlined over the observation period. The absence of effective countermeasures, combined with growing antibiotic resistance that negates the effectiveness of multiple antibiotics, highlights the potential for S. marcescens infections to trigger serious clinical complications and increased mortality rates. The surveillance of Serratia marcescens infections constitutes a pivotal element in refining empiric therapy to mitigate the dissemination of antimicrobial resistance.

Root canal treatment represents a significant challenge as current cleaning and disinfection methodologies fail to remove persistent bacterial biofilms within the intricate anatomical structures. Recently, the field of nanotechnology has emerged as a promising frontier with numerous biomedical applications. Among the most notable contributions of nanotechnology are nanoparticles, which possess antimicrobial, antifungal, and antiviral properties. Nanoparticles cause the destructuring of bacterial walls, increasing the permeability of the cell membrane, stimulating the generation of reactive oxygen species, and interrupting the replication of deoxyribonucleic acid through the controlled release of ions. Thus, they could revolutionize endodontics, obtaining superior results and guaranteeing a promising short- and long-term prognosis. Therefore, chitosan, silver, graphene, poly(lactic) co-glycolic acid, bioactive glass, mesoporous calcium silicate, hydroxyapatite, zirconia, glucose oxidase magnetic, copper, and zinc oxide nanoparticles in endodontic therapy have been investigated in the present review. The diversified antimicrobial mechanisms of action, the numerous applications, and the high degree of clinical safety could encourage the scientific community to adopt nanoparticles as potential drugs for the treatment of endodontic diseases, overcoming the limitations related to antibiotic resistance and eradication of the biofilm.

Corynebacterium striatum ( C. striatum ) is an emerging multidrug-resistant (MDR) pathogen associated with nosocomial infections. In this scenario, we screened the antimicrobial activity of the anthelmintic drugs doramectin, moxidectin, selamectin and niclosamide against 20 C. striatum MDR clinical isolates. Among these, niclosamide was the best performing drug against C. striatum . Niclosamide cytotoxicity was evaluated by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay on immortalized human keratinocyte cells (HaCaT). After 20 h of treatment, the recorded 50% cytotoxic concentration (CC 50 ) was 2.56 μg/mL. The antibacterial efficacy was determined via disc diffusion, broth microdilution method and time-killing. Against C. striatum , niclosamide induced a growth inhibitory area of 22 mm and the minimum inhibitory concentration that inhibits 90% of bacteria (MIC 90 ) was 0.39 μg/mL, exhibiting bactericidal action. The biofilm biomass eradicating action was investigated through crystal violet (CV), MTT and confocal laser scanning microscopy (CLSM). Niclosamide affected the biofilm viability in a dose-dependent manner and degraded biomass by 55 and 49% at 0.39 μg/mL and 0.19 μg/mL. CLSM images confirmed the biofilm biomass degradation, showing a drastic reduction in cell viability. This study could promote the drug-repurposing of the anthelmintic FDA-approved niclosamide as a therapeutic agent to counteract the C. striatum MDR infections.

Aerobic vaginitis (AV) is a vaginal infectious condition, characterized by a high inflammatory response and/or signs of epithelial atrophy, a decrease in the amount of Lactobacillus spp. and an increase in enteric origin bacteria. AV, often misdiagnosed, is difficult to treat due to the emerging spread of multi-drug resistant bacterial strains. The present study aimed to define the prevalence of AV, to detect causative bacteria and their antimicrobial resistance pattern. Women 10-95 years old, admitted to San Giovanni di Dio e Ruggi d'Aragona Hospital, Salerno, Italy (in the years 2015-2019) are included in the study. Bacterial identification and antibiotic susceptibility tests were carried out by VITEK ® 2. Among 2069 patients, 1176 tested positive for microbial growth. A higher incidence of infection was found in the 55-64 age group. Among the pathogenic strains, 50.4% were Gram-negative, and 49.6% were Gram-positive. Escherichia coli ( E. coli ) (32.5%) was the most representative strain, followed by Enterococcus faecalis ( E. faecalis ) (29.4%), Klebsiella pneumoniae ( K. pneumoniae ) (7.8%) and Enterococcus faecium ( E. faecium ) (7.7%). E. coli showed high sensitivity to carbapenems and amikacin. K. pneumoniae carbapenems resistance was fluctuating over time. Alarming resistance to vancomycin was not recorded for Enterococci . Both strains were sensitive to teicoplanin, linezolid and tigecycline. Proper diagnosis and an effective therapeutic approach are needed to improve AV management.

Ocular bacterial infections represent a serious problem that affecting people of all age and genders. These infections can lead to visual impairment and blindness if not properly treated. The current study evaluates the antimicrobial resistance profiles and the resistance trend of both Staphylococcus aureus ( S. aureus ) and coagulase-negative staphylococci (CoNS), the main pathogens involved in eye infections. A total of 322 isolates of S. aureus and CoNS, were collected from patients with bacterial conjunctivitis and keratitis at the "Luigi Vanvitelli" University Hospital of Campania in Naples, Italy, between 2017 and 2020. The isolated bacteria showed a high percentage of resistance to methicillin and other antibiotics commonly used for the treatment of ocular infections. Trends in antibiotic resistance were not encouraging, recording-especially among CoNS strains-an increase of more than 20% in resistance to methicillin and aminoglycosides during the study period. Instead, the resistance rates to tetracycline had a significant decrease in CoNS isolates while no changes in their susceptibility to fluoroquinolones and macrolides were observed. However, all isolates showed no resistance to trimethoprim/sulfamethoxazole and chloramphenicol. In this scenario, preventive identification of the infection causative agents and the evaluation of the antimicrobial susceptibility patterns are essential to set up an ocular infection effective drug treatment and also prevent antibiotic resistance.

Bloodstream infections (BSIs) are among the leading causes of morbidity and mortality worldwide, among infectious diseases. Local knowledge of the main bacteria involved in BSIs and their associated antibiotic susceptibility patterns is essential to rationalize the empiric antimicrobial therapy. The aim of this study was to define the incidence of infection and evaluate the antimicrobial resistance profile of the main pathogens involved in BSIs. This study enrolled patients of all ages and both sexes admitted to the University Hospital "San Giovanni di Dio e Ruggi d'Aragona", Salerno, Italy between January 2015 to December 2019. Bacterial identification and antibiotic susceptibility testing were performed with Vitek 2. A number of 3.949 positive blood cultures were included out of 24,694 total blood cultures from 2015 to 2019. Coagulase-negative staphylococci (CoNS) were identified as the main bacteria that caused BSI (17.4%), followed by Staphylococcus aureus (12.3%), Escherichia coli (10.9%), and Klebsiella pneumoniae (9.4%). Gram-positive bacteria were highly resistant to Penicillin G and Oxacillin, while Gram-negative strains to Ciprofloxacin, Cefotaxime, Ceftazidime, and Amoxicillin-clavulanate. High susceptibility to Vancomycin, Linezolid, and Daptomycin was observed among Gram-positive strains. Fosfomycin showed the best performance to treatment Gram-negative BSIs. Our study found an increase in resistance to the latest generation of antibiotics over the years. This suggests an urgent need to improve antimicrobial management programs to optimize empirical therapy in BSI.

Urinary tract infections (UTIs) are the most common and expensive health problem globally. The treatment of UTIs is difficult owing to the onset of antibiotic-resistant bacterial strains. The aim of this study was to define the incidence of infections, identify the bacteria responsible, and identify the antimicrobial resistance profile. Patients of all ages and both sexes were included in the study, all admitted to University Hospital of Campania "Luigi Vanvitelli", between January 2017 and December 2018. Bacterial identification and antibiotic susceptibility testing were performed using matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and Phoenix BD. Among the 1745 studied patients, 541 (31%) and 1204 (69%) were positive and negative for bacterial growth, respectively. Of 541 positive patients, 325 (60%) were females, while 216 (39.9%) were males. The largest number of positive subjects was recorded in the elderly (>61 years). Among the pathogenic strains, 425 (78.5%) were Gram-negative, 107 (19.7%) were Gram-positive, and 9 (1.7%) were Candida species. The most isolated Gram-negative strain is Escherichia coli ( E. coli ) (53.5%). The most frequent Gram-positive strain was Enterococcus faecalis ( E. faecalis ) (12.9%). Gram-negative bacteria were highly resistant to ampicillin, whereas Gram-positive bacteria were highly resistant to erythromycin., Competing Interests: Ethical Statement: Ethical approval by the Human Research Ethics Committee was not requested, as our study used laboratory management data and clinical information on patients, collected from databases. This is retrospective study and not directly associated with patients.