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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. [ABSTRACT FROM AUTHOR]

Molecular dynamics simulations and experiments showed the existence of a well-defined second coordination shell around the paramagnetic ion of chromium(III), (Cr(H2O)6)3+, in aqueous solutions. Strong hydrogen bonds were formed upon polarization of first coordination sphere water molecules, resulting in a mean coordination number of 12.94 water molecules in the second shell and providing evidence that solvent exchange processes occur within the second coordination shell of chromium(III).

Molecular dynamics simulations for lanthanide ions Ln3+ in aqueous solution involving the mean water polarization in the first hydration shell reveal a coordination number of 8.5 for the middle of the lanthanide series. This corresponds to an equilibrium between a 9-coordinated and an 8-coordinated Ln3+-aqua ion. The frequent movement of the ninth water molecule between the first hydration shell and the bulk decreases the time water molecules stay in the first hydration shell.

Langmuirisotherm, neutron reflectivity, and Brewster angle microscopyexperiments have been performed to study the interaction of amphotericinB (AmB) with monolayers prepared from 1-palmitoyl-2-oleoylphosphatidylcholine(POPC) and mixtures of this lipid with cholesterol or ergosterol tomimic mammalian and fungal cell membranes, respectively. Isothermdata show that AmB causes a more pronounced change in surface pressurein the POPC/ergosterol system than in the POPC and POPC/cholesterolsystems, and its interaction with the POPC/ergosterol monolayer isalso more rapid than with the POPC and POPC/cholesterol monolayers.Brewster angle microscopy shows that, in interaction with POPC monolayers,AmB causes the formation of small domains which shrink and disappearwithin a few minutes. The drug also causes domain formation in thePOPC/cholesterol and POPC/ergosterol monolayers; in the former case,these are formed more slowly than is seen with the POPC monolayersand are ultimately much smaller; in the latter case, they are formedrather more quickly and are more heterogeneous in size. Neutron reflectivitydata show that the changes in monolayer structure following interactionwith AmB are the same for all three systems studied: the data areconsistent with the drug inserting into the monolayers with its macrocyclicring intercalated among the lipid acyl chains and sterol ring systems,with its mycosamine moiety colocalizing with the sterol hydroxyl andPOPC head groups. On the basis of these studies, it is concluded thatAmB inserts in a similar manner into POPC, POPC/cholesterol, and POPC/ergosterolmonolayers but does so with differing kinetics and with the formationof quite different in-plane structures. The more rapid time scalefor interaction of the drug with the POPC/ergosterol monolayer, itsmore pronounced effect on monolayer surface pressure, and its moremarked changes as regards domain formation are all consistent withthe drug’s selectivity for fungal vs mammalian cell membranes. [ABSTRACT FROM AUTHOR]

The study objective is to examine epidemiological and microbiological aspects of aerobic vaginitis in female patients admitted to University Hospital of Campania "L. Vanvitelli" over five years. The most represented strains were E. coli (n = 153), Citrobacter spp. increasing from 2020, E. faecalis (n = 149), S. haemolitycus (n = 61), and Candida albicans (n = 87). The susceptibility patterns of a selection of gram-negative and gram-positive representative bacterial isolates were examined. Carbapenems, aminoglycosides, and fosfomycin were most effective against gram-negative bacteria, whereas vancomycin, daptomycin, and linezolid exhibited greater efficacy against gram-positive bacteria. None of the E. coli and Citrobacter spp. isolates produced extended-spectrum beta-lactamases, and the S. haemolyticus strains were methicillin-resistant. In gram-positive isolates, gentamicin susceptibility increased in 2020 and 2021 compared to clindamycin; erythromycin showed high resistance rates in 2020. Our findings indicate that integrating proper microbiological cultures into clinical practice could improve the management of aerobic vaginitis. Moreover, they highlight the necessity of establishing a nationwide surveillance guideline to mitigate antimicrobial resistance. Improvement actions in antimicrobial diagnostic stewardship must be considered when seeking the appropriate diagnosis and treatment for aerobic vaginitis.

Aims: Multidrug resistance is a worrying problem worldwide. The lack of readily available drugs to counter nosocomial infections requires the need for new interventional strategies. Drug repurposing represents a valid alternative to using commercial molecules as antimicrobial agents in a short time and with low costs. Contextually, the present study focused on the antibacterial potential of the ammonium salt N-nitroso-N-phenylhydroxylamine (Cupferron), evaluating the ability to inhibit microbial growth and influence the main virulence factors., Methods and Results: Cupferron cytotoxicity was checked via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) and hemolysis assays. The antimicrobial activity was assessed through the Kirby-Bauer disk diffusion test, broth microdilution method, and time-killing kinetics. Furthermore, the impact on different stages of the biofilm life cycle, catalase, swimming, and swarming motility was estimated via MTT and crystal violet (CV) assay, H2O2 sensitivity, and motility tests, respectively. Cupferron exhibited <15% cytotoxicity at 200 µg/mL concentration. The 90% bacterial growth inhibitory concentrations (MIC90) values recorded after 24 hours of exposure were 200 and 100 µg/mL for multidrug-resistant (MDR) and sensitive strains, respectively, exerting a bacteriostatic action. Cupferron-treated bacteria showed increased susceptibility to biofilm production, oxidative stress, and impaired bacterial motility in a dose-dependent manner., Conclusions: In the new antimicrobial compounds active research scenario, the results indicated that Cupferron could be an interesting candidate for tackling Escherichia coli infections., (© The Author(s) 2023. Published by Oxford University Press on behalf of Applied Microbiology International.)

In a framework aimed at the recovery and enhancement of medicinal plants endemic to the territory of the Cilento and Vallo di Diano National Park, Lavandula austroapennina N.G. Passal., Tundis and Upson has aroused interest. An insight into the chemical composition of the corolla, calyx, leaf, stem, and root organs was carried out following ultrasound-assisted maceration in n -hexane. The obtained lipophilic extracts were explored using ultra-high-performance chromatography coupled to high-resolution mass spectrometry (UHPLC-ESI-QqTOF-MS/MS). The extracts from the different organs varied in their relative content of fatty acids, ursanes, and oleanane-type triterpenes. In particular, the oleanolic acid content appeared to increase in the order of corolla < leaf < stem. An MTT assay was performed to verify the possible cytotoxicity of the organ extracts of L. austroapennina at a concentration ranging from 12.5 to 400 µg/mL on the Vero CCL-81 cell line. Antiviral activity against herpes simplex virus type 1 (HSV-1), alpha human coronavirus 229E (HCoV-229E), and poliovirus type 1 (PV-1) was evaluated via a plaque reduction assay in the same cellular model. All the extracts did not show cytotoxic effects after 2 and 24 h exposure times, and the antiviral efficacy was particularly important for the stem extract, capable of completely inhibiting the tested viruses at low doses. The antiviral activity in a non-enveloped virus PV-1 allowed the assertion that the extracts from the organs of L. austroapennina , and especially the stem extract, interfered directly with the viral envelope. This study underlines how much knowledge of a territory's medicinal plant heritage is a harbinger of promising discoveries in the health field.

In recent years, the resistance of pathogenic microorganisms to common antimicrobial agents has raised to a severe public health problem. The moderate and wise use of antimicrobials and the prevention of infections are the most effective strategies for decreasing the spread and development of resistance. Therefore, the World Health Organization (WHO) has intensified the search for new drugs to fight emerging pathogens. Antimicrobial peptides (AMPs), also known as host defense peptides (HDPs), play a crucial role in innate immunity, representing one of the first line of defense against microbial attacks. In this study, we evaluated the antibacterial activity of the AMP named Hylin-a1 (derived from the skin of the frog Heleioporus albopunctatus ) against Staphylococcus aureus strains. S. aureus represents a commensal bacterium but also the principal causative agent of several human infections, including bacteremia, endocarditis, skin and device-related infections. Hylin-a1 toxicity was evaluated on human keratinocytes; once the non-cytotoxic concentration range was determined, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were analyzed, and time-killing assays were performed to verify the bacteriostatic and/or bactericidal activity of the peptide. We found that Hylin-a1 exerted a bacteriostatic action against most of the tested strains, with 90% inhibition at the concentration of 6.25 μM. Noteworthy, the peptide at a very low concentration (~3 μM) significantly blocked the growth of β-lactam- and methicillin-resistant S. aureus . The levels of interleukin (IL)-1β, IL-6 and IL-8 were quantified through a molecular assay, indicating that the peptide was able also to regulate the inflammatory response following bacterial infection. The effect of Hylin-a1 on S. aureus cell morphology was also evaluated. Altogether, these results indicate the high therapeutic potential of Hylin-a1 against a wide variety of clinical manifestations caused by S. aureus .

Multidrug-resistant (MDR)/extensively drug-resistant (XDR) Pseudomonas aeruginosa is emerging as a major threat related to adverse patient outcomes. The goal of this review is to describe evidence-based empiric and targeted treatment regimens that can be exploited when dealing with suspected or confirmed infections due to MDR/XDR P. aeruginosa . P. aeruginosa has inherent resistance to many drug classes, the capacity to form biofilms, and most importantly, the ability to quickly acquire resistance to ongoing treatments. Based on the presence of risk factors for MDR/XDR infections and local epidemiology, where large proportions of strains are resistant to classic beta-lactams, the recommended empirical treatment for suspected P. aeruginosa infections is based on ceftolozane-tazobactam or ceftazidime-avibactam. Where local epidemiology indicates low rates of MDR/XDR and there are no risk factors, a third or fourth generation cephalosporin can be used in the context of a "carbapenem-sparing" strategy. Whenever feasible, antibiotic de-escalation is recommended after antimicrobial susceptibility tests suggest that it is appropriate, and de-escalation is based on different resistance mechanisms. Cefiderocol and imipenem-cilastatin-relebactam withstand most resistance mechanisms and may remain active in cases with resistance to other new antibiotics. Confronting the growing threat of MDR/XDR P. aeruginosa , treatment choices should be wise, sparing newer antibiotics when dealing with a suspected/confirmed susceptible P. aeruginosa strain and choosing the right option for MDR/XDR P. aeruginosa based on specific types and resistance mechanisms.

The aim of this study was to describe the prevalence and epidemiology distribution of K. pneumoniae isolated at University Hospital of Campania "Luigi Vanvitelli," including the susceptibility evolution profile. Data on resistant phenotype strains, such as extended-spectrum-β-lactamase (ESBL) producers and carbapenem-resistant K. pneumoniae (CRE) isolates, were also reported. K. pneumoniae strains were collected at the Complex Operative Unit (UOC) of Virology and Microbiology from different colonization and infection sites from January 2016 to December 2020. The highest rates of isolation were in urinary samples and in respiratory and wound swabs. Antibiotics susceptibility patterns showed more than 50% of the isolates resistant to cephalosporins, fluoroquinolones and penicillin. On the other hand, from 20% to 40% of K. pneumoniae strains were resistant to carbapenems and aminoglycosides. Based on our analysis, fosfomycin, ceftazidime/avibactam and ceftolozane/tazobactam are still therapeutic alternatives. Data analysis on carbapenem class evolution in 2016-2020 showed a significant increase in resistance rates (p<0.05). Increased rates in CRE and ESBL producing K. pneumoniae since 2017 were reported. Providing information on clinical characteristics and epidemiology data on contemporary K. pneumoniae evolution could help mitigate the spread of these isolates in our hospital and avert the endemic levels that have been observed in Southern Italy and in other European countries.

Antibiotic resistance is an important and emerging alarm for public health that requires development of new potential antibacterial strategies. In recent years, nanoscale materials have emerged as an alternative way to fight pathogens. Many researchers have shown great interest in nanoparticles (NPs) using noble metals, such as silver, gold, and platinum, even though numerous nanomaterials have shown toxicity. To overcome the problem of toxicity, nanotechnology merged with green chemistry to synthesize nature-friendly nanoparticles from plants. Here, we describe the synthesis of NPs using silver (AgNPs) and platinum (PtNPs) alone or in combination (AgPtNPs) in the presence of Ocimum basilicum ( O. basilicum ) leaf extract. O. basilicum is a well-known medicinal plant with antibacterial compounds. A preliminary chemical-physical characterization of the extract was conducted. The size, shape and elemental analysis were carried out using UV-Visible spectroscopy, dynamic light scattering (DLS), and zeta potential. Transmission electron microscopy (TEM) confirmed polydisperse NPs with spherical shape. The size of the particles was approximately 59 nm, confirmed by DLS analysis, and the polydisperse index was 0.159. Fourier transform infrared (FTIR) demonstrated an effective and selective capping of the phytoconstituents on the NPs. The cytotoxic activities of AgNPs, PtNPs and AgPtNPs were assessed on different epithelial cell models, using the 3-[4.5-dimethylthiazol-2-yl]-2.5-diphenyltetrazolium bromide (MTT) cell proliferation assay, and discovered low toxicity, with a cell viability of 80%. The antibacterial potential of the NPs was evaluated against Escherichia coli ( E. coli ), Enterococcus faecalis ( E. faecalis ), Klebsiella pneumonia ( K. pneumoniae ), and Staphylococcus aureus ( S. aureus ) strains. Minimum inhibitory concentration (MIC) assays showed AgPtNP activity till the least concentration of NPs (3.15-1.56 µg/mL) against ATCC, MS, and MDR E. coli , E. faecalis , and S. aureus and the Kirby-Bauer method showed that AgPtNPs gave a zone of inhibition for Gram-positive and Gram-negative bacteria in a range of 9-25 mm. In addition, we obtained AgPtNP synergistic activity in combination with vancomycin or ampicillin antibiotics. Taken together, these results indicate that bimetallic nanoparticles, synthesized from O. basilicum leaf extract, could represent a natural, ecofriendly, cheap, and safe method to produce alternative antibacterial strategies with low cytotoxicity.