Lipopolysaccharide (LPS) of Gram-negative bacteria and several surface components of Gram-positive bacteria utilize CD14 and CD11a/18 as cellular receptors to induce expression and release of cytokines. Of the surface components of Gram-negative bacteria, porins exhibit a biological activity similar to that of LPS. The results in this paper show that the mechanism of stimulation by porins of THP-1 cells enriched in CD14 receptor after treatment with 1,25-dihydroxyvitamin D3 (vitamin D3) is independent of this receptor, but is partially dependent on CD11a/18 integrins.

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the important pathogens worldwide showing resistance to several widely used antibiotics. This has made the treatment of MRSA infections harder, especially due to their prevalence in the hospital setting. We evaluated the antibiotic susceptibility patterns of healthcare-associated MRSA infections with a focus on Vancomycin Intermediate S. Aureus (VISA) and macrolide-licosamide-streptogramin B (MLS_B) phenotypes. A total of 417 Staphylococcus aureus (S. aureus) cases were isolated between January 2017 and December 2018, through several clinical specimens collected from the University Hospital ‘Luigi Vanvitelli’ of Naples. We identified bacterial strains using Matrix-Assisted Laser Desorption/Ionization-Time of Flight (MALDI-TOF) and antimicrobial susceptibility using Phoenix BD (Becton Dickinson, NJ, USA). Out of the total 417 S. aureus cases, 140 were MRSA (33.6%) and of these, 50% were soft tissue infections. All MRSA and Methicillin sensible S.aureus MSSA isolates were susceptible to linezolid and daptomycin. Two MRSA cases exhibited intermediate resistance to vancomycin and were of constitutive MLS_B phenotype. Among the MRSA strains, 11.4% were constitutive and 43.6% were inducible MLS_B phenotypes and 8.6% were macrolide-streptogramin B phenotype. This study characterized the epidemiological status, antibiotic resistance patterns, and current prevalent phenotypes of healthcare-associated MRSA. This knowledge can aid clinicians in improving the antimicrobial stewardship program by adapting appropriate guidelines for the proper use of MRSA antibacterial agents.

Background: Acinetobacter baumannii is a significant pathogen and a major contributor to healthcare-associated infections, particularly in intensive care units. Its high potential for developing multiple drug resistance (MDR) makes it a challenging pathogen to manage. This study investigates the prevalence and resistance patterns of MDR A. baumannii isolates over a six-year period at a university hospital in Southern Italy. Objective: The aims of this study are to evaluate recent trends in the prevalence of MDR A. baumannii, analyze resistance patterns, and assess the impact of the antimicrobial diagnostic stewardship program implemented in 2018. Methods: This retrospective cohort study was conducted at the University Hospital of Campania “Luigi Vanvitelli” from 2018 to 2023. A total of 191 A. baumannii isolates from blood, urine, and wound samples were analyzed. Antimicrobial susceptibility testing was performed following EUCAST guidelines. The prevalence of MDR strains was assessed across three periods: pre-pandemic (2018–2019), during the pandemic (2020–2021), and post-pandemic (2022–2023) Results: Among the 191 isolates, 89.5% were classified as MDR. The highest number of isolates occurred in 2020, with blood cultures and urine samples increasing by 40.9% and 62.5%, respectively, while wound isolates decreased by 34.2%. The implementation of antimicrobial diagnostic stewardship programs correlated with a reduction in carbapenem resistance in 2020 and 2022. However, resistance to meropenem and colistin persisted. A 60.4% decline in total isolation from 2020 to 2023 suggests effective infection control measures. Conclusions: MDR A. baumannii remains a significant threat to healthcare. Although there have been slight reductions in resistance following antimicrobial stewardship interventions, persistent resistance to last-line antibiotics underscores the urgent need for alternative treatments, enhanced surveillance, and stricter infection control strategies.

Bloodstream infections (BSI) are associated with high morbidity and mortality. This study aimed to describe the epidemiology of BSI and antimicrobial resistance patterns amongst its common bacterial causes. We conducted a retrospective record review of blood culture results of patients hospitalized with BSI at University Hospital ‘L. Vanvitelli’ from 2016 to 2021. For each patient records were obtained from the database using microbiological information. Gram-positive bacteria were the most predominant pathogens followed by Gram-negative bacteria. Among all isolates, bacterial pathogens most frequently identified included coagulase-negative Staphylococci (CoNS), Klebsiella pneumoniae, Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and enterococci. We noted a general decrease in antimicrobial resistance amongst BSI pathogens in the latter years of the study. High levels of macrolide and aminoglycoside resistance amongst CoNS were reported. Carbapenem resistance amongst E. coli was barely reported, while resistance rates amongst K. pneumoniae declined considerably between 2018 and 2021. The prevalence of methicillin-resistant S. aureus decreased during the study period while that of methicillin-resistant CoNS remained relatively high throughout. The prevalence of extended spectrum ß-lactamase – producing E. coli increased considerably between 2016 and 2018 but showed a slight decrease thereafter. Conversely, there was a general decline in the resistant rates of extended spectrum ß-lactamase – producing K. pneumoniae between 2016 and 2018 with a similar trend being noted for carbapenem resistance in K. pneumoniae. Continuously monitoring the changes in the trends in BSI microbiological profiles, including pathogen profiles and the associated antibiotic resistance patterns, can help diagnostic approaches, treatment strategies and prevention programs.

Background: This study explored knowledge, attitudes, and behaviors regarding antibiotics among adolescents. Methods: The cross-sectional study was conducted from February to April 2024. Results: Overall, 65.2% of adolescents believed that antibiotics should only be used when prescribed, this was more likely among women and those who needed additional information regarding antibiotics. Women and adolescents without a parent with a chronic disease, who believed that it is not possible to stop antibiotics when symptoms improve and who disagreed that antibiotics are faster treatment for flu were more likely to prefer prescribed antibiotics. Antibiotic use without a medical prescription was reported by 37.4% of participants, and this was more likely among men and adolescents who had a parent with a chronic disease, who needed additional information regarding antibiotics, and who disagreed that antibiotics should only be used when prescribed. Adolescents who are afraid that antimicrobial resistance (AMR) may affect their health, who received previous information about AMR, who know that antibiotics are not useful for viral infection treatment, and who need additional information regarding antibiotics, were more likely to believe that it is important to talk about AMR at school. Conclusions: Interventions on AMR and antibiotic use among adolescents are needed.