Does early combination vs. Monotherapy improve clinical outcomes of clinically extremely vulnerable patients with COVID-19? Results from a retrospective propensity-weighted analysis.

BACKGROUND: The potential efficacy of early combination therapy, based on an antiviral plus a monoclonal antibody, for COVID-19 in severely immunocompromised patients is matter of debate. OBJECTIVES: Our aim was to describe the impact on clinical outcomes of COVID-19 treatments in severely immunocompromised individuals, evaluating differences between a combination and a monotherapy. METHODS: We included severely immunocompromised outpatients with mild-to-moderate COVID-19 who received an early treatment (either monotherapy with nirmatrelvir/ritonavir or remdesivir or the combination of an antiviral plus sotrovimab). We then assessed differences between the two treatment strategies on three main outcomes (30-day mortality, access to emergency department, hospitalization), separately and as a composite by using a propensity score weighted (PSW) approach. RESULTS: Eighty one severely immunocompromised patients were included, 39 receiving early combination therapy and 42 receiving monotherapy. No significant difference was observed in the 30-day mortality rate and hospitalization rate between subjects in the two groups, while access to the emergency department following treatment administration was significantly higher in people who received a combination therapy. After applying the PSW, it was observed that combination therapy impacted favourably on the composite outcome, in a statistically significant fashion. In addition, PSW approach for mortality showed that age was the only significant factor influencing the death as stand-alone outcome. CONCLUSIONS: Early combination therapy showed a favourable impact on a composite outcome (including mortality, hospitalizations and access to emergency department) in severely immunocompromised hosts who were all vaccinated. However, further studies are needed to support our results.

Short Course Antibiotic Therapy for Catheter-Related Septic Thrombosis: "Caveat Emptor!": Duration of Therapy Should Not Be Set a Priori.

There is a growing body of evidence showing no significant difference in clinical outcomes in patients with uncomplicated Gram-negative bloodstream infections (BSIs) receiving 7 or 14 days of therapy. However, the scenario may differ when complicated forms of BSI, such as catheter-related BSIs (CRBSIs) burdened by septic thrombosis (ST), are considered. A recent study showed that a short course of antimicrobial therapy (≤3 weeks) had similar outcomes to a prolonged course on CRBSI-ST. From this perspective, starting from the desirable goal of shortening the treatment duration, we discuss how the path to the correct diagnosis and management of CRBSI-ST may be paved with several challenges. Indeed, patients with ST due to Gram-negative bacteria display prolonged bacteremia despite an indolent clinical course, requiring an extended course of antibiotic treatment guided by negative FUBCs results, which should be considered the real driver of the decision-making process establishing the length of antibiotic therapy in CRBSI-ST. Shortening treatment of complicated CRBSIs burdened by ST is ambitious and advisable; however, a dynamic and tailored approach driven by a tangible outcome such as negative FUBCs rather than a fixed-duration paradigm should be implemented for the optimal antimicrobial duration.

A rare association of liver abscess and rhabdomyolysis induced by Klebsiella oxytoca.

INTRODUCTION: We report the case of a 76-year-old male who was hospitalized with severe dehydration, pain in the hepatic region, and weakness in the limbs. METHODOLOGY: A contrast-enhanced abdomen CT and a contrast-enhanced ultrasound identified a large liver abscess. The patient underwent percutaneous drainage of the abscess. RESULTS: The culture examination, analyzed by multiplex polymerase chain reaction test, showed the presence of Klebsiella oxytoca. The laboratory report identified a resistance mechanism involving a plasmid-mediated SHV-1 extended-spectrum-beta-lactamase (ESBL). CONCLUSIONS: K. oxytoca is a Gram-negative bacterium and is potentially associated with a large variety of infections. The association between the liver abscess by K. oxytoca and rhabdomyolysis had not yet been described in the literature.

Human Campylobacter spp. infections in Italy.

PURPOSE: Campylobacter is a frequent cause of enteric infections with common antimicrobial resistance issues. The most recent reports of campylobacteriosis in Italy include data from 2013 to 2016. We aimed to provide national epidemiological and microbiological data on human Campylobacter infections in Italy during the period 2017-2021. METHODS: Data was collected from 19 Hospitals in 13 Italian Regions. Bacterial identification was performed by mass spectrometry. Antibiograms were determined with Etest or Kirby-Bauer (EUCAST criteria). RESULTS: In total, 5419 isolations of Campylobacter spp. were performed. The most common species were C. jejuni (n = 4535, 83.7%), followed by C. coli (n = 732, 13.5%) and C. fetus (n = 34, 0.6%). The mean age of patients was 34.61 years and 57.1% were males. Outpatients accounted for 54% of the cases detected. Campylobacter were isolated from faeces in 97.3% of cases and in 2.7% from blood. C. fetus was mostly isolated from blood (88.2% of cases). We tested for antimicrobial susceptibility 4627 isolates (85.4%). Resistance to ciprofloxacin and tetracyclines was 75.5% and 54.8%, respectively; resistance to erythromycin was 4.8%; clarithromycin 2% and azithromycin 2%. 50% of C. jejuni and C. coli were resistant to ≥ 2 antibiotics. Over the study period, resistance to ciprofloxacin and tetracyclines significantly decreased (p < 0.005), while resistance to macrolides remained stable. CONCLUSION: Campylobacter resistance to fluoroquinolones and tetracyclines in Italy is decreasing but is still high, while macrolides retain good activity.

Intravenous Fosfomycin for Systemic Multidrug-Resistant Pseudomonas aeruginosa Infections.

Human Pseudomonas infections have high morbidity and mortality rates. Pseudomonas bacteria can cause sepsis or septic shock; they produce biofilm and commonly exhibit a multidrug-resistant phenotype. The choice of antimicrobial therapy in many cases is challenging, and deep knowledge of clinical, microbiological, and pharmacological issues is required. Intravenous fosfomycin is being repurposed in a combination given its favorable pharmacokinetic/pharmacodynamic properties (a small molecule with favorable kinetic both in bloodstream infection and in deep-seated infections), antibiofilm activity, and its interesting synergistic effects with other antimicrobials. Recent literature on epidemiological, microbiological, pharmacological, and clinical data on intravenous fosfomycin therapy against Pseudomonas is herein reviewed and discussed.

Editorial for the Special Issue: "The Issue of Multidrug-Resistant Pathogens in Nosocomial Infections".

Antimicrobial resistance (AMR) is a global problem; in 2019, before the Coronavirus Disease 2019 (COVID-19) pandemic, it was responsible of more deaths than any other infectious diseases, including human immunodeficiency virus and malaria [...].

Stenotrophomonas maltophilia Infections: A Systematic Review and Meta-Analysis of Comparative Efficacy of Available Treatments, with Critical Assessment of Novel Therapeutic Options.

Stenotrophomonas maltophilia (SM) represents a challenging pathogen due to its resistance profile. A systematic review of the available evidence was conducted to evaluate the best treatment of SM infections to date, focusing on trimethoprim/sulfamethoxazole (TMP/SMX), fluoroquinolones (FQs), and tetracycline derivatives (TDs). MATERIALS: PubMed/MEDLINE and Embase were searched from inception to 30 November 2022. The primary outcome was all-cause mortality. Secondary outcomes included clinical failure, adverse events, and length of stay. A random effects meta-analysis was performed. This study was registered with PROSPERO (CRD42022321893). RESULTS: Twenty-four studies, all retrospective, were included. A significant difference in terms of overall mortality was observed when comparing as a monotherapy TMP/SMX versus FQs (odds ratio (OR) 1.46, 95% confidence interval (CI) 1.15-1.86, I2 = 33%; 11 studies, 2407 patients). The prediction interval (PI) did not touch the no effect line (1.06-1.93), but the results were not robust for the unmeasured confounding (E-value for point estimate of 1.71). When comparing TMP/SMX with TDs, the former showed an association with higher mortality but not significant and with a wide PI (OR 1.95, 95% CI 0.79-4.82, PI 0.01-685.99, I2 = 0%; 3 studies, 346 patients). Monotherapies in general exerted a protective effect against death opposed to the combination regimens but were not significant (OR 0.71, 95% CI 0.41-1.22, PI 0.16-3.08, I2 = 0%; 4 studies, 438 patients). CONCLUSIONS: Against SM infections, FQs and, possibly, TDs seem to be reasonable alternative choices to TMP/SMX. Data from clinical trials are urgently needed to better inform therapeutic choices in this setting by also taking into account newer agents.

Impact of oral antiviral therapy against HCV on gut microbiota. A prospective study.

The intestinal microbiota plays a fundamental role in physiological homeostasis as well as in pathologic conditions. Hepatitis C virus is the leading cause of chronic liver diseases worldwide. The treatment of this infection has been revolutionized by the availability of direct-acting antiviral agents which guarantee a high rate (about 95%) of viral clearance. Few studies have assessed the change in the gut microbiota of patients treated with direct-acting antiviral agents against HCV, and many aspects still need to be clarified. The aim of the study was to evaluate the effects of antiviral therapy on gut microbiota. We enrolled patients with HCV-related chronic liver disease attending the Infectious Diseases Unit of the A.O.U. Federico II of Naples from January 2017 to March 2018 and treated with DAAs. For each patient, a fecal sample was collected and analyzed for the assessment of microbial diversity before the start of therapy and by SVR12 time. We excluded patients who had received antibiotics in the previous 6 months. Twelve patients were enrolled (6 male, 8 genotype 1 (1 subtype 1a), 4 genotype 2). Fibrosis scores were F0 in 1 patient, F2 in 1 patient, F3 in 4 patients and cirrhosis in the remaining 6 (all in Child-Pugh class A). All were treated with DAAs for 12 weeks (5 with Paritaprevir-Ombitasvir-Ritonavir-Dasabuvir, 3 with Sofosbuvir-Ledipasvir, 1 with Sofosbuvir-Ribavirin, 1 with Sofosbuvir-Daclatasvir, 1 with Sofosbuvir-Velpatasvir) and 100% achieved SVR12. In all patients, we observed a trend in reduction of potentially pathogenic microorganisms (i.e., Enterobacteriaceae). Furthermore, a trend of increase in α-diversity was observed in patients by SVR12 compared to baseline. This trend was markedly more evident in patients without liver cirrhosis than in those with cirrhosis. Our study shows that viral eradication obtained with DAA is associated with a trend in restoring the heterogeneity of α-diversity and in reducing the percentage of potentially pathogenic microbial species, although this benefit is less evident in patients with cirrhosis. Further studies with larger sample size are needed to confirm these data.

Remdesivir treatment and clinical outcome in non-severe hospitalized COVID-19 patients: a propensity score matching multicenter Italian hospital experience.

INTRODUCTION: Remdesivir exerts positive effects on clinical improvement, even though it seems not to affect mortality among COVID-19 patients; moreover, it was associated with the occurence of marked bradycardia. METHODS: We retrospectively evaluated 989 consecutive patients with non-severe COVID-19 (SpO2 ≥ 94% on room air) admitted from October 2020 to July 2021 at five Italian hospitals. Propensity score matching allowed to obtain a comparable control group. Primary endpoints were bradycardia onset (heart rate < 50 bpm), acute respiratory distress syndrome (ARDS) in need of intubation and mortality. RESULTS: A total of 200 patients (20.2%) received remdesivir, while 789 standard of care (79.8%). In the matched cohorts, severe ARDS in need of intubation was experienced by 70 patients (17.5%), significantly higher in the control group (68% vs. 31%; p < 0.0001). Conversely, bradycardia, experienced by 53 patients (12%), was significantly higher in the remdesivir subgroup (20% vs. 1.1%; p < 0.0001). During follow-up, all-cause mortality was 15% (N = 62), significantly higher in the control group (76% vs. 24%; log-rank p < 0.0001), as shown at the Kaplan-Meier (KM) analysis. KM furthermore showed a significantly higher risk of severe ARDS in need of intubation among controls (log-rank p < 0.001), while an increased risk of bradycardia onset in the remdesivir group (log-rank p < 0.001). Multivariable logistic regression showed a protective role of remdesivir for both ARDS in need of intubation (OR 0.50, 95%CI 0.29-0.85; p = 0.01) and mortality (OR 0.18, 95%CI 0.09-0.39; p < 0.0001). CONCLUSIONS: Remdesivir treatment emerged as associated with reduced risk of severe acute respiratory distress syndrome in need of intubation and mortality. Remdesivir-induced bradycardia was not associated with worse outcome.

CEFTO-CURE study: CEFTObiprole Clinical Use in Real-lifE - a multi-centre experience in Italy.

BACKGROUND: Ceftobiprole is approved in Europe for treatment of community-acquired pneumonia and non-ventilator-associated hospital-acquired pneumonia (HAP) in adults. Real-world data are limited. METHODS: This multi-centre, observational, ambispective investigator-initiated study was undertaken in Italy from January 2018 to December 2019 in order to evaluate the use of ceftobiprole in a real-world setting. RESULTS: Overall, 195 patients from 10 centres were evaluated (68% retrospectively). Male sex was prevalent (n=121, 62%). Median age was 67 [interquartile range (IQR) 53-75] years. Median Charlson Comorbidity Index score was 5 (IQR 3-7). The most common indication was pneumonia (151/195, 77%), especially HAP. Other uses were skin and soft tissue infections (5%), endocarditis (4%) and bone infections (4%). Ceftobiprole was usually an empiric choice (65%), in combination with other drugs (66%) and as second-line therapy (58%). A causative agent was found in 39% of cases. A diagnosis of sepsis was made in 59 cases (30%). Success in the clinically evaluable population (excluding 12 cases due to isolation of pathogens outside ceftobiprole's spectrum of activity) was obtained in 79% of cases, with all-cause mortality of 20%. On multi-level analysis, three predictors were positively associated with clinical success: male gender, pneumonia and detection of causal agent. Sepsis was a negative predictor. Nine factors were independently associated, favourably or unfavourably, with fatal outcome. CONCLUSIONS: Ceftobiprole is a safe and effective therapeutic choice, even in a real-world setting. More data are needed to establish its efficacy in patients with sepsis.

Mortality Attributable to Bloodstream Infections Caused by Different Carbapenem-Resistant Gram-Negative Bacilli: Results From a Nationwide Study in Italy (ALARICO Network).

BACKGROUND: Our aim was to analyze mortality attributable to carbapenem-resistant (CR) gram-negative bacilli (GNB) in patients with bloodstream infections (BSIs). METHODS: Prospective multicentric study including patients with GNB-BSI from 19 Italian hospitals (June 2018-January 2020). Patients were followed-up to 30 days. Primary outcomes were 30-day mortality and attributable mortality. Attributable mortality was calculated in the following groups: Klebsiella pneumoniae carbapenemase (KPC)-producing Enterobacterales, metallo-ß-lactamases (MBL)-producing Enterobacterales, CR-Pseudomonas aeruginosa (CRPA), CR-Acinetobacter baumannii (CRAB). A multivariable analysis with hospital fixed-effect was built to identify factors associated with 30-day mortality. Adjusted OR (aORs) were reported. Attributable mortality was calculated according to the DRIVE-AB Consortium. RESULTS: Overall, 1276 patients with monomicrobial GNB BSI were included: 723/1276 (56.7%) carbapenem-susceptible (CS)-GNB, 304/1276 (23.8%) KPC-, 77/1276 (6%) MBL-producing CRE, 61/1276 (4.8%) CRPA, and 111/1276 (8.7%) CRAB BSI. Thirty-day mortality in patients with CS-GNB BSI was 13.7% compared to 26.6%, 36.4%, 32.8% and 43.2% in patients with BSI by KPC-CRE, MBL-CRE, CRPA and CRAB, respectively (P < .001). On multivariable analysis, age, ward of hospitalization, SOFA score, and Charlson Index were factors associated with 30-day mortality, while urinary source of infection and early appropriate therapy resulted protective factors. Compared to CS-GNB, MBL-producing CRE (aOR 5.86, 95% CI 2.72-12.76), CRPA (aOR 1.99, 95% CI 1.48-5.95) and CRAB (aOR 2.65, 95% CI 1.52-4.61) were significantly associated with 30-day mortality. Attributable mortality rates were 5% for KPC-, 35% for MBL, 19% for CRPA, and 16% for CRAB. CONCLUSIONS: In patients with BSIs, carbapenem-resistance is associated with an excess of mortality, with MBL-producing CRE carrying the highest risk of death.

Predisposing factor, impactful adjunctive treatment or unfavorable prognostic marker: a meta-analysis on the elusive role of dexamethasone for Listeria monocytogenes meningitis.

INTRODUCTION: There are no randomized controlled trials to inform the choice of using adjunctive dexamethasone (AD) against Listeria monocytogenes meningitis (LMM) and data from observational studies are pretty conflicting. METHODOLOGY: We performed a rapid review of the literature with quantitative analysis. A pairwise random-effects meta-analysis was implemented, pooling unadjusted and adjusted data. The main outcome was mortality. RESULTS: Across all included studies (five) informing the main analysis on raw mortality data, 199 patients received AD, as opposed to 382 who did not receive AD. All-cause mortality was slightly lower in patients undergoing AD, but not in a statistically significant manner: odds ratio 0.96, 95% confidence interval 0.42-2.19. The prediction interval was very wide (0.06-15.99), suggesting that in future studies the effect of AD might be either beneficial or harmful. CONCLUSIONS: The role of AD for LMM still needs to be established being the current evidence inconclusive and heterogeneous.

Epidemiology, Mechanisms of Resistance and Treatment Algorithm for Infections Due to Carbapenem-Resistant Gram-Negative Bacteria: An Expert Panel Opinion.

Antimicrobial resistance represents a serious threat for global health, causing an unacceptable burden in terms of morbidity, mortality and healthcare costs. In particular, in 2017, carbapenem-resistant organisms were listed by the WHO among the group of pathogens for which novel treatment strategies are urgently needed. Fortunately, several drugs and combinations have been introduced in recent years to treat multi-drug-resistant (MDR) bacteria. However, a correct use of these molecules is needed to preserve their efficacy. In the present paper, we will provide an overview on the epidemiology and mechanisms of resistance of the most common MDR Gram-negative bacteria, proposing a treatment algorithm for the management of infections due to carbapenem-resistant bacteria based on the most recent clinical evidence.

COVID-19 Post-Exposure Evaluation (COPE) Study: Assessing the Role of Socio-Economic Factors in Household SARS-CoV-2 Transmission within Campania Region (Southern Italy).

Campania is the sixth poorest region of Italy, and it is the region with the highest income inequality. The secondary attack rates of SARS-CoV-2 among households are found to be substantially heterogeneous among published studies and are influenced by socio-economic factors. We conducted a retrospective study to describe the role of socio-economic factors in the household transmission of SARS-CoV-2 among patients living in Campania Region and referring to "Federico II" Hospital. We interviewed 413 subjects followed-up for COVID-19 between the 8 March 2020 and the 24 May 2021 with the aim to collect demographic, clinical, economic, and social data regarding their household and the index cases. The variables associated with SARS-CoV-2 attack rate higher than 50% among households were higher age (p = 0.023) and higher Charlson Comorbidity Index of the index case (p = 0.023) and, for household characteristics, higher number of families per house (p = 0.02), location of the houses in Naples' suburbs (Chi2 = 5.3, p = 0.02) and in Caserta City area (Chi2 = 4, p = 0.04), and renting the house compared to owning it (Chi2 = 5.83, p = 0.01). This study confirms the finding described by other authors that household transmission of SARS-CoV-2 is correlated with the income inequality of the analyzed geographical area as well as with the indicators of health and economic wealth of the families, and this correlation also applies to the Campania Region.

Diagnosis and management of infections caused by multidrug-resistant bacteria: guideline endorsed by the Italian Society of Infection and Tropical Diseases (SIMIT), the Italian Society of Anti-Infective Therapy (SITA), the Italian Group for Antimicrobial Stewardship (GISA), the Italian Association of Clinical Microbiologists (AMCLI) and the Italian Society of Microbiology (SIM).

Management of patients with infections caused by multidrug-resistant organisms is challenging and requires a multidisciplinary approach to achieve successful clinical outcomes. The aim of this paper is to provide recommendations for the diagnosis and optimal management of these infections, with a focus on targeted antibiotic therapy. The document was produced by a panel of experts nominated by the five endorsing Italian societies, namely the Italian Association of Clinical Microbiologists (AMCLI), the Italian Group for Antimicrobial Stewardship (GISA), the Italian Society of Microbiology (SIM), the Italian Society of Infectious and Tropical Diseases (SIMIT) and the Italian Society of Anti-Infective Therapy (SITA). Population, Intervention, Comparison and Outcomes (PICO) questions about microbiological diagnosis, pharmacological strategies and targeted antibiotic therapy were addressed for the following pathogens: carbapenem-resistant Enterobacterales; carbapenem-resistant Pseudomonas aeruginosa; carbapenem-resistant Acinetobacter baumannii; and methicillin-resistant Staphylococcus aureus. A systematic review of the literature published from January 2011 to November 2020 was guided by the PICO strategy. As data from randomised controlled trials (RCTs) were expected to be limited, observational studies were also reviewed. The certainty of evidence was classified using the GRADE approach. Recommendations were classified as strong or conditional. Detailed recommendations were formulated for each pathogen. The majority of available RCTs have serious risk of bias, and many observational studies have several limitations, including small sample size, retrospective design and presence of confounders. Thus, some recommendations are based on low or very-low certainty of evidence. Importantly, these recommendations should be continually updated to reflect emerging evidence from clinical studies and real-world experience.

Anaerobic bloodstream infections in Italy (ITANAEROBY): A 5-year retrospective nationwide survey.

INTRODUCTION: A lack of updated data on the burden and profile of anaerobic bloodstream infections (ABIs) exists. We assessed the incidence of ABIs and trends in antimicrobial resistance in anaerobes isolated from blood in Italy. MATERIAL AND METHODS: We conducted a retrospective study on 17 Italian hospitals (2016-2020). Anaerobes isolated from blood culture and their in vitro susceptibility profiles (EUCAST-interpreted) were registered and analyzed. RESULTS: A total of 1960 ABIs were identified. The mean age of ABIs patients was 68.6 ± 18.5 years, 57.6% were males. The overall incidence rate of ABIs was 1.01 per 10.000 patient-days. Forty-seven% of ABIs occurred in medical wards, 17% in ICUs, 14% in surgical wards, 7% in hemato-oncology, 14% in outpatients. The three most common anti-anaerobic tested drugs were metronidazole (92%), clindamycin (89%) and amoxicillin/clavulanate (83%). The three most common isolated anaerobes were Bacteroides fragilis (n = 529), Cutibacterium acnes (n = 262) and Clostridium perfringens (n = 134). The lowest resistance rate (1.5%) was to carbapenems, whereas the highest rate (51%) was to penicillin. Clindamycin resistance was >20% for Bacteroides spp., Prevotella spp. and Clostridium spp. Metronidazole resistance was 9.2% after excluding C. acnes and Actinomyces spp. Bacteroides spp. showed an increased prevalence of clindamycin resistance through the study period: 19% in 2016, 33% in 2020 (p ≤ 0.001). CONCLUSIONS: Our data provide a comprehensive overview of the epidemiology of ABIs in Italy, filling a gap that has existed since 1995. Caution is needed when clindamycin is used as empirical anti-anaerobic drug.

Epidemiology, aetiology and treatment of skin and soft tissue infections: final report of a prospective multicentre national registry.

Skin and soft tissue infections (SSTIs) represent a heterogenous group of pathological conditions involving the skin or the underlying subcutaneous tissues, fascia and muscle, characterised by a considerable variety of clinical presentations, severity and possible aetiological pathogens. Although previous analyses on restricted types of SSTIs and population have already been published, we conducted a large nationwide surveillance program on behalf of the Italian Society of Infectious and Tropical Diseases to assess the clinical and microbiological characteristics of the whole SSTI spectrum, from mild to severe life-threatening infections, in both inpatients and outpatients and their management. Twenty-nine Infectious Diseases (ID) Centres throughout Italy collected prospectively data concerning both the clinical and microbiological diagnosis of patients affected by SSTIs via an electronic case report form. We included in our database all cases managed by ID specialists participating to the study, independently from their severity or the setting of consultation. Here, we integrated previous preliminary results analysing and reporting data referring to a 3-year period (October 2016-October 2019). During this period, the study population included 478 adult patients with diagnosis of SSTI. The type of infection diagnosed, the aetiological agent involved and some notes on antimicrobial susceptibilities were collected and reported herein. We also analysed the most common co-morbidities, the type and duration of therapy executed, before and after ID intervention and the length of stay. The results of our study provide information to better understand the national epidemiologic data and the current clinical management of SSTIs in Italy.

Emerging Treatment Options for Acute Bacterial Skin and Skin Structure Infections and Bloodstream Infections Caused by Staphylococcus aureus: A Comprehensive Review of the Evidence.

Staphylococcus aureus remains an important human pathogen of concern, with mortality rates surpassing 30% in the case of severe systemic infections. Distinguishing methicillin-susceptible S. aureus from methicillin-resistant S. aureus (MRSA) is fundamental for therapeutic choices. A crucial emerging concept in the treatment of acute bacterial skin and skin structure infections is the availability of various approved agents with anti-MRSA activity, which allow a personalized approach based on the characteristics of any given patient while at the same time remaining in line with high certainty efficacy evidence from large randomized controlled trials. Regarding the treatment of S. aureus bloodstream infections (BSI), interesting aspects that may become relevant in the near future are the presence of both old and novel agents in phase-2 or phase-3 of clinical development for this indication, and the pressing need for high certainty evidence to guide the possible use of combination therapy in specific categories or phenotypes of patients with complicated MRSA BSI.