Sepsis is a serious and life-threatening medical emergency associated with dysregulated host immune responses to infection. Like cerebral vascular or acute cardiovascular incidents, sepsis is considered a time-dependent condition having severe and long-term consequences on human health. Apart from organ support, prompt administration of appropriate antimicrobial therapy is crucial to limit the burden of complications related to sepsis in ICU patients. The management of septic patients requires comprehensive and multi-disciplinary strategies for an adequate diagnosis. Most of the ICU population receives empirical antibiotic therapy without having a confirmed diagnosis. The misuse of antibiotics in intensive care units may increase the possibility of developing multidrug resistance along with considerable ecological side effects. The first doses of empirical anti-microbial therapy are slightly higher, regardless of the presence or absence of organ dysfunction, which may upregulate the production of circulating pro-and-anti-inflammatory mediators, having negative effects on the general well-being of the patients. This notion supports the introduction of individualized antimicrobial approaches based on local patterns of resistance to ensure the appropriate dosage of empirical therapy, as well as to limit the emergence of multidrug resistance in advanced-care patients. The adequacy and treatment duration must be viewed at regular intervals for effective de-escalation, and novel diagnostic approaches must be introduced to improve the quality of care in the ICU population.

The purpose of the present study was to investigate anti-staphylococcal activity of liposomal daptomycin, against four biofilm-producing S. aureus and S. epidermidis clinical strains, three of which are methicillin resistant. Neutral and negatively charged Daptomycin-loaded liposomes were prepared by three methods thin film hydration (TFH), DRV and microfluidic mixing (MM), and characterized for drug encapsulation (EE%), size distribution, zeta-potential, vesicle stability, drug release and drug integrity. Interestingly, whilst drug loading in THF and DRV nanosized (by extrusion) vesicles was around 30-35, very low loading (~4%) was possible in MM vesicles, requiring further explanatory investigations. Liposomal encapsulation protected daptomycin from degradation and preserve its bioactivity. Quantitative microtiter plate (crystal violet, CV), methylthiazoltetrazolium (MTT), and growth curve (GC) assays evaluated antimicrobial activity of neutral and negative charge daptomycin-liposomes towards planktonic bacteria and biofilms. Neutral liposomes exhibited dramatically enhanced inhibition of bacteria growth (compared to free drug) for all species studied, while negative charged liposomes were totally inactive. Biofilm prevention and treatment studies revealed high antibiofilm activity of liposomal daptomycin. Neutral liposomes were more active for prevention and negative charge ones for treating established biofilms. Planktonic bacteria as well as matured biofilms of low daptomycin susceptible MRSE and MRSA strains were almost completely eradicated by liposomal-daptomycin indicating the need for their further exploration as antimicrobial therapeutics.