Beyond the distance between juridic and scientific decision-making process: An evidence-based prediction algorithm for professional liability assessment in healthcare-associated infections.

BACKGROUND: HAIs (Healthcare-Acquired-Infections) have been recently the subject of judgment n. 6386 pronounced on 3rd March 2023 by the Italian Supreme Court. This sentence provided three criteria to determine whether a health facility is responsible for the patient contracting a nosocomial infection, i.e. time criterion, topographical criterion and clinical criterion. Accordingly, the healthcare facility is obliged to prove the fulfillment of a series of preventive hygiene measures specifically detailed by the legislator. Herein, the positive predictive value of these criteria ("juridic criteria") in the identification of professional liability for nosocomial infections was evaluated in comparison with clinical criteria reviewed by Infectious Disease specialists ("Infectious-Disease criteria", i.e. presence of a Multidrug Resistant Organism (MDRO); development of surgical site infection; inadequate antibiotic therapy; inadequate disinfection). METHODS: Two retrospective cohorts were compared from the Portal of Telematic Services of the Ministry of Justice; 51 patients were extrapolated from Italian judgments concerning claims for Gram-negative nosocomial infections in the three-year period 2020-2022. On the other side, from the electronic database of University Hospital of Bari we extracted 349 patients affected by Gram-negative infections in the same timespan. Both "juridic" criteria and "Infectious-Disease" criteria were then applied to the full cohort after stratification for cohort of origin and after stratification for nosocomial or non-nosocomial infections. Predictive value of criteria was evaluated through receiver operating characteristic (ROC) curves and area under the curve (AUC). RESULTS: Overall, the incidence of definite nosocomial infections (according to final judgement or clinical records discharge letter) was 84 % in juridic cohort and 46 % in "real-world" series. Data suggested that the presence of all three juridic criteria [ROC AUC = 0.944 (95%CI = 0.924-0.963)] or the four clinical criteria [ROC AUC = 0.948 (95%CI = 0.928-0.969)] predicted well a case of nosocomial infection with professional liability. Moreover, by summarizing both criteria in a single classification system, the generated ROC curve (was the one with the highest AUC [0.9488 (95%CI = 0.928-0.969)]. Accordingly, further tests were performed, evaluating the predictive value of one juridic criterium plus at one of more Infectious-Disease criteria. Interestingly, the ROCs curves demonstrated that the presence of at least 1 juridic criteria plus at least 2 Infectious Disease criteria reached a predictive value comparable to 2 or 3 juridic criteria. CONCLUSIONS: The results highlight the efficiency of new criteria laid down in the judgment of the Italian Supreme Court to attribute liability for nosocomial infection despite the disputed distance between juridic and scientific decision-making process. In addition, the use of a combined score combining "juridic" and "Infectious-Disease" criteria provides a high-quality tool to be used by technical consultants to make up for lack of clinical documentation by passing judgments concerning litigation about professional liability in case of nosocomial infections. This sheds light on the possibility to face worldwide judicial inquiries with scientific rigor.

Safety and effectiveness of fifth generation cephalosporins for the treatment of methicillin-resistant staphylococcus aureus bloodstream infections: a narrative review exploring past, present, and future.

INTRODUCTION: Methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infection (BSI) is a major issue in healthcare, since it is often associated with endocarditis or deep site foci. Relevant morbidity and mortality associated with MRSA-BSIs forced the development of new antibiotic strategies; in particular, this review will focus the attention on fifth-generation cephalosporins (ceftaroline/ceftobiprole), that are the only ß-lactams active against MRSA. AREAS COVERED: The review discusses the available randomized controlled trials and real-world observational studies conducted on safety and effectiveness of ceftaroline/ceftobiprole for the treatment of MRSA-BSIs. Finally, a proposal of MRSA-BSI treatment flowchart, based on fifth-generation cephalosporins, is described. EXPERT OPINION: The use of anti-MRSA cephalosporins is an acceptable choice either in monotherapy or combination therapy for the treatment of MRSA-BSIs due to their relevant effectiveness and safety. Particularly, their use may be advisable in combination therapy in case of severe infections (including endocarditis or persistent bacteriemia) or in monotherapy in subjects at higher risk of drugs-induced toxicity with older regimens. On the contrary, caution should be taken in case of suspected/ascertained central nervous system infections due to inconsistent data regarding penetration of these drugs in cerebrospinal fluid and brain tissues.

Dual combined antiviral treatment with remdesivir and nirmatrelvir/ritonavir in patients with impaired humoral immunity and persistent SARS-CoV-2 infection.

Despite global vaccination efforts, immunocompromized patients remain at high risk for COVID-19-associated morbidity. In particular, patients with impaired humoral immunity have shown a high risk of persistent infection. We report a case series of adult patients with B cell malignancies and/or undergoing B cell targeting therapies with persisting SARS-CoV-2 infection and treated with a combination antiviral therapy of remdesivir and nirmatrelvir/ritonavir, in three Italian tertiary academic hospitals. A total of 14 patients with impaired adaptive humoral immunity and prolonged SARS-CoV-2 infection were treated with the dual antiviral therapy. The median age was 60 (IQR 56-68) years, and 11 were male. Twelve patients had B cell lymphoma, one patient had chronic lymphocytic leukemia and one patient had multiple sclerosis. Thirteen out of 14 patients had received prior B cell-targeting therapies, consisting of anti-CD20 monoclonal antibodies in 11 patients, and chimeric antigen receptor T therapy in 2 patients. The median time between diagnosis and therapy start was 42.0 (IQR 35-46) days. Seven patients had mild, 6 moderate and one severe disease. Nine patients had signs of interstitial pneumonitis on chest computed tomography scans before treatment. The median duration of nirmatrelvir/ritonavir and remdesivir combination therapy was 10 days. All patients showed resolution of COVID-19-related symptoms after a median of 6 (IQR 4-11) days and viral clearance after 9 (IQR 5-11) days. Combination therapy with remdesivir and nirmatrelvir/ritonavir is a promising treatment option for persistent COVID-19 in immunocompromized patients with humoral immunity impairment, worthy of prospective comparative trials.

Identify Drug-Resistant Pathogens in Patients with Community-Acquired Pneumonia.

A substantial increase in broad-spectrum antibiotics as empirical therapy in patients with community-acquired pneumonia (CAP) has occurred over the last 15 years. One of the driving factors leading to that has been some evidence showing an increased incidence of drug-resistant pathogens (DRP) in patients from a community with pneumonia, including methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa. Research has been published attempting to identify DRP in CAP through the implementation of probabilistic approaches in clinical practice. However, recent epidemiological data showed that the incidence of DRP in CAP varies significantly according to local ecology, healthcare systems and countries where the studies were performed. Several studies also questioned whether broad-spectrum antibiotic coverage might improve outcomes in CAP, as it is widely documented that broad-spectrum antibiotics overuse is associated with increased costs, length of hospital stay, drug adverse events and resistance. The aim of this review is to analyze the different approaches used to identify DRP in CAP patients as well as the outcomes and adverse events in patients undergoing broad-spectrum antibiotics.

What do clinicians mean by epidemics' preparedness.

BACKGROUND: Infectious disease pandemics and epidemics pose significant global threats, and the risk of emerging infectious diseases has increased because of factors such as international connections, travel, and population density. Despite investments in global health surveillance, much of the world remains unprepared to manage infectious disease threats. OBJECTIVES: This review article discusses the general considerations and lessons learned from the COVID-19 pandemic in terms of epidemic preparedness. SOURCES: Non-systematic search on PubMed, scientific society websites, and scientific newspapers (performed in April 2023). CONTENT: Key factors for preparedness include robust public health infrastructure, adequate allocation of resources, and effective communication between stakeholders. This narrative review emphasizes the need for timely and accurate dissemination of medical knowledge, as well as addressing the challenges of misinformation and infodemics. It also highlights the importance of quick availability of diagnostic tests and vaccines, ensuring equitable access to these technologies. The role of scientific coordination in developing treatment strategies and the safety and mental well-being of healthcare workers are discussed. Lastly, it should be emphasized the need for medical training, multidisciplinary teams, new technologies and artificial intelligence, and the active role of infectious disease physicians in epidemic preparedness efforts. IMPLICATIONS: From clinicians' perspective, healthcare authorities play a crucial role in epidemic preparedness even by providing resource management plans, ensuring availability of essential supplies and training, facilitating communication, and improving safe infection management.

Outcome of early treatment of SARS-CoV-2 infection in patients with haematological disorders.

Outcome of early treatment of COVID-19 with antivirals or anti-spike monoclonal antibodies (MABs) in patients with haematological malignancies (HM) is unknown. A retrospective study of HM patients treated for mild/moderate COVID-19 between March 2021 and July 2022 was performed. The main composite end-point was treatment failure (severe COVID-19 or COVID-19-related death). We included 328 consecutive patients who received MABs (n = 120, 37%; sotrovimab, n = 73) or antivirals (n = 208, 63%; nirmatrelvir/ritonavir, n = 116) over a median of two days after symptoms started; 111 (33.8%) had non-Hodgkin lymphoma (NHL); 89 (27%) were transplant/CAR-T (chimaeric antigen receptor T-cell therapy) recipients. Most infections (n = 309, 94%) occurred during the Omicron period. Failure developed in 31 patients (9.5%). Its independent predictors were older age, fewer vaccine doses, and treatment with MABs. Rate of failure was lower in the Omicron versus the pre-Omicron period (7.8% versus 36.8%, p < 0.001). During the Omicron period, predictors of failure were age, fewer vaccine doses and diagnosis of acute myeloid leukaemia/myelodysplastic syndrome (AML/MDS). Independent predictors of longer viral shedding were age, comorbidities, hospital admission at diagnosis, NHL/CLL, treatment with MABs. COVID-19-associated mortality was 3.4% (n = 11). The mortality in those who developed severe COVID-19 after early treatment was 26% in the Omicron period. Patients with HM had a significant risk of failure of early treatment, even during the Omicron period, with high mortality rate.

Colonization by ceftazidime/avibactam-resistant KPC-producing Klebsiella pneumoniae following therapy in critically ill patients.

OBJECTIVES: Ceftazidime-avibactam (CAZ-AVI)-based treatments have been associated with the emergence of resistance in KPC-producing Klebsiella pneumoniae (KPC-Kp) isolates after antimicrobial exposure. Here, we evaluated the CAZ-AVI resistance development in KPC-Kp isolated from patients treated with CAZ-AVI-based therapy. METHODS: We enrolled adult patients treated with CAZ-AVI-based regimens between January 2020 and January 2021. Carbapenemase-producing isolates collected from clinical samples and rectal swabs were evaluated for CAZ-AVI resistance development after antimicrobial exposure. KPC-Kp developing CAZ-AVI resistance and parental susceptible strains were genomically characterized. Whole genome sequencing was performed by using the Illumina iSeq100 platform and genomes were analyzed for antimicrobial-resistance genes, plasmid and porins sequences. RESULTS: We enrolled 90 patients treated with CAZ-AVI-based therapy and 62.2% (56/90) of them were colonized by KPC-producers before CAZ-AVI-based treatment and 6.6% acquired colonization during therapy. Six (6.6%) patients developed infections because of resistant KPC-Kp after CAZ-AVI exposure and 3 (3.3%) of them developed CAZ-AVI resistance in the rectum. Development of resistance among KPC in the rectum occurred after 32 (IQR, 9-35) days of therapy and after 30 (IQR, 22-40) days in clinical specimens. Genetic analysis demonstrated that the development of CAZ-AVI resistance was associated with mutated blaKPC-3 (blaKPC-31, blaKPC-53, blaKPC-89, and blaKPC-130) and phylogenetic analysis demonstrated a close genomic relationship between KCP-Kp collected from rectum and clinical samples of the same patient. DISCUSSION: Antimicrobial exposure induce a higher incidence of CAZ-AVI resistance development in the blood and respiratory tract than in the rectum (6.7% vs. 3.3%) of CAZ-AVI-treated patients and genome analysis showed that resistance was associated with mutated blaKPC-3 variants.

Predictors of clinical evolution of SARS-CoV-2 infection in hematological patients: A systematic review and meta-analysis.

Main aim of this systematic review is to quantify the risk and identify predictors of clinical evolution of SARS-CoV-2 in hematological patients compared to different control populations. Two independent reviewers screened the literature assessing clinical outcomes of SARS-CoV-2 infection in adult patients with active hematological malignancies published up to June 2021. Primary outcome was COVID-19 related mortality, secondary outcomes were hospital and intensive-care admission, mechanical ventilation (MV), and thromboembolic events. Variables related to study setting, baseline patients' demographic, comorbidities, underlying hematological disease, ongoing chemotherapy, COVID-19 presentation, and treatments were extracted. A total of 67 studies including 10,061 hematological patients and 111,143 controls were included. Most of the studies were retrospective cohorts (51 studies, 76%) and only 19 (13%) provided data for a control group. A significant increased risk of clinical progression in the hematological population compared to the controls was found in terms of COVID-19 related mortality (OR, 2.12; 95% CI, 1.77-2.54), hospitalization (OR, 1.98; 95% CI, 1.15-3.43), intensive-care admission (OR, 1.77; 95% CI, 1.38-2.26), and MV (OR, 2.17; 95% CI, 1.71-2.75). The risk remained significantly higher in the subgroup analysis comparing hematological patients versus solid cancer. Meta-regression analysis of uncontrolled studies showed that older age, male sex, and hypertension were significantly related to worse clinical outcomes of COVID-19 in hematological population. Older age and hypertension were found to be associated also to thromboembolic events. In conclusion, hematological patients have a higher risk of COVID-19 clinical progression compared to both the general population and to patients with solid cancer.

Increase in invasive group A streptococcal infections in Milan, Italy: a genomic and clinical characterization.

Background: Group A Streptococcus (GAS) causes multiple clinical manifestations, including invasive (iGAS) or even life-threatening (severe-iGAS) infections. After the drop in cases during COVID-19 pandemic, in 2022 a sharp increase of GAS was reported globally. Methods: GAS strains collected in 09/2022-03/2023 in two university hospitals in Milan, Italy were retrospectively analyzed. Clinical/epidemiological data were combined with whole-genome sequencing to: (i) define resistome/virulome, (ii) identify putative transmission chains, (iii) explore associations between emm-types and clinical severity. Results: Twenty-eight isolates were available, 19/28 (67.9%) from adults and 9/28 (32.1%) from pediatric population. The criteria for iGAS were met by 19/28 cases (67.9%), of which 11/19 (39.3%) met the further criteria for severe-iGAS. Pediatric cases were mainly non-invasive infections (8/9, 88.9%), adult cases were iGAS and severe-iGAS in 18/19 (94.7%) and 10/19 (52.6%), respectively. Thirteen emm-types were detected, the most prevalent being emm1 and emm12 (6/28 strains each, 21.4%). Single nucleotide polymorphism (SNP) analysis of emm1.0 and emm12.0 strains revealed pairwise SNP distance always >10, inconsistent with unique transmission chains. Emm12.0-type, found to almost exclusively carry virulence factors speH and speI, was mainly detected in children and in no-iGAS infections (55.6 vs. 5.3%, p = 0.007 and 66.7 vs. 0.0%, p < 0.001, respectively), while emm1.0-type was mainly detected in severe-iGAS (0.0 vs. 45.5%, p = 0.045). Conclusions: This study showed that multiple emm-types contributed to a 2022/2023 GAS infection increase in two hospitals in Milan, with no evidence of direct transmission chains. Specific emm-types could be associated with disease severity or invasiveness. Overall, these results support the integration of classical epidemiological studies with genomic investigation to appropriately manage severe infections and improve surveillance.

Neutralizing monoclonal antibodies for early treatment of hospital-acquired SARS-CoV-2 infection in hematologic patients.

Efficacy of early treatment with anti-SARS-CoV-2 spike protein monoclonal antibodies (mAbs) for nosocomial SARS-CoV-2 infection in hematologic patients is unknown. Retrospective, cohort study conducted in four Italian teaching hospitals. We included adult patients with hematologic malignancies and hospital-acquired SARS-CoV-2 infection diagnosed between November 2020 and December 2021. The principal exposure variable was administration of mAbs. The primary endpoint was clinical failure dea composite outcome of mortality and/or invasive and noninvasive ventilation within 90 days from infection onset. We included 52 patients with hospital-acquired SARS-CoV-2 infection. Males were 29 (60%), median age was 62 (interquartile range [IQR] 48-70). Forty-five (86%) patients were on chemotherapy or had received chemotherapy within 30 days. MAbs were administered in 19/52 (36%) patients. Clinical failure occurred in 22 (42%) patients; 21% (4/19) in mAbs group versus 54% (18/33) in non-mAbs group (p = 0.03). Other predictors of clinical failure were older age (median [IQR] 69 [61-72] versus 58 [46-66], p = 0.001), and higher Charlson comorbidity index (median [IQR], 5 [3.25-5] versus 3 [2-5], p = 0.002). At multivariable Cox regression model, mAbs were independently associated with a significantly lower rate of clinical failure (HR 0.11, 95% CI 0.01-0.85, p = 0.01), after adjusting for confounders. In conclusion, mAbs are promising for early treatment of hematologic patients with healthcare-related SARS-CoV-2 infection.

European society of clinical microbiology and infectious diseases guidelines for coronavirus disease 2019: an update on treatment of patients with mild/moderate disease.

SCOPE: Despite the large availability of vaccines, coronavirus disease 2019 (COVID-19), induced by severe acute respiratory syndrome coronavirus 2, continues to be a major threat for health-care providers and fragile people. A number of options are now available for outpatients with mild-to-moderate COVID-19 at the risk of disease progression for the prevention of deaths or hospitalization. METHODS: A European Society of Clinical Microbiology and Infectious Diseases COVID-19 guidelines task force was established by the European Society of Clinical Microbiology and Infectious Diseases Executive Committee. A small group was established, half appointed by the chair and the remaining selected based on an open call. Each panel met virtually once a week. For all decisions, a simple majority vote was used. A long list of clinical questions using the population, intervention, comparison, outcome format was developed at the beginning of the process. For each population, intervention, comparison, outcome, two panel members performed a literature search, with a third panelist involved in case of inconsistent results. Voting was based on the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. RECOMMENDATIONS: In this update, we focus on anti-viral agents, monoclonal antibodies (mAbs) and other treatment options proposed for patients with mild or moderate COVID-19 who are at the risk of hospitalization or death. Although the use of anti-virals is recommended, especially nirmatrelvir/ritonavir and remdesivir or, alternatively, molnupirarvir, the administration of mAbs against the spike protein strictly depends on circulating variants or the ability to test timely for variants and sub-variants. At the time of writing (April-June 2022), the only active mAb was tixagevimab/cilgavimab given the predominance of the Omicron BA.2, BA.3, BA.4 and BA.5 sub-lineages in Europe. However, considering that the epidemiological scenario is extremely dynamic, constant monitoring of variants of concern is mandatory.

Treatment duration for central line-associated infection caused by Enterococcus spp.: a retrospective evaluation of a multicenter cohort.

Objective of this study was to assess the appropriate treatment duration for enterococcal central line-associated bloodstream infections (CLABSIs). This observational, retrospective, multicenter study conducted between 2011 and 2019 enrolled all hospitalized patients with monomicrobial enterococcal CLABSI. Those with infective endocarditis and non-survivors at least 7 days from index blood culture (BC) were excluded. Primary endpoint was 30-day mortality. We enrolled 113 patients, of whom 59% were male, median age was 64 (SD ± 15) and median Charlson's index score 5 (IQR 3-8). Enterococcus faecalis and Enterococcus faecium were found in 51% and 44% of cases, respectively. Median treatment duration was 11 days (IQR 6-17), and 32% of patients (n = 36) received ≤ 7 days. Characteristics of patients receiving more or less than 7 days of treatment were similar. Central line was removed in 82% (n = 93) of cases within a median of 3 days (1-8). At both uni- and multivariate analysis, duration of antibiotic treatment > 7 days was not associated with 30-day mortality [HR 0.41 (95% CI, 0.13-1.24), p = 0.12] even after adjustment with propensity score [HR 0.47 (95% CI 0.17-1.26), p = 0.13]. A 7-day treatment course appears to be safe in non-complicated enterococcal CLABSIs.

Risk factors for persistent enterococcal bacteraemia: a multicentre retrospective study.

OBJECTIVES: Conditions favouring persistent enterococcal bacteraemia (p-EB) have not been fully investigated yet. The aim of our study is to analyse risk factors for p-EB and its impact on mortality. METHODS: International two-centre retrospective study of all hospitalised adults with enterococcal bacteraemia managed with follow-up blood cultures (BCs) during the period 2011-2019. Exclusion criteria were: (1) death within 72 hours from index BCs and (2) polymicrobial bacteraemia. Primary endpoint was p-EB, defined as further isolation of the same species of Enterococcus spp. from BCs after at least 72 hours of appropriate antibiotic therapy. Multivariable logistic regression model was performed to assess risk factors for p-EB. The impact of p-EB on 30-day mortality was assessed by Kaplan-Meier survival curve and Cox regression multivariable model. RESULTS: During the study period, 244 enterococcal bacteraemia were diagnosed. P-EB were 13.5% (33/244). At multivariable analysis, factors independently associated with p-EB were hematologic malignancy (OR 4.60 [95% CI 1.32-16.00], P = 0.01), infective endocarditis (OR 7.99 [95% CI 2.20-28.9], P = 0.002), and use of daptomycin as initial treatment (OR 4.50 [95% CI 1.29-15.61], P = 0.018). Mortality rate was higher in the p-EB group (32% vs. 18%). Kaplan-Meier survival curve showed that patients with p-EB were less likely to survive at 30 days from index BCs (log-rank P = 0.002). Using a Cox regression model, independent predictors of 30-day mortality were hematologic malignancy (HR 2.30 [95% CI 1.02-4.11], P = 0.043), p-EB (HR 1.93 [95% CI 0.92-4.04], P = 0.08), and septic shock (HR 5.92 [95% CI 2.17-16.30], P = 0.001). CONCLUSION: P-EB was diagnosed mainly in very fragile patients and in those receiving daptomycin as frontline therapy. P-EB may have an impact on mortality.

Dynamic evolution of imipenem/relebactam resistance in a KPC-producing Klebsiella pneumoniae from a single patient during ceftazidime/avibactam-based treatments.

OBJECTIVES: The novel carbapenem/ß-lactamase inhibitor combination imipenem/cilastatin/relebactam has been developed for the treatment of infections due to carbapenemase-producing Enterobacteriaceae (CPE). Herein, we describe the in vivo evolution of imipenem/cilastatin/relebactam resistance in longitudinal intra-patient Klebsiella pneumoniae carbapenemase (KPC)-producing Klebsiella pneumoniae (KPC-Kp) strains isolated from a patient following ceftazidime/avibactam-based treatments. METHODS: WGS analysis was performed on KPC-Kp strains isolated at different times and during antimicrobial treatments from the same patient. Genome assemblies were performed using a hybrid approach using Illumina iSeq 100 and Minion Oxford Nanopore platforms. Subpopulation analysis and allele frequency determination was performed by mapping Illumina reads to blaKPC. RESULTS: During antimicrobial treatment, resistance to ceftazidime/avibactam was observed following 16 days of antimicrobial therapy. WGS results showed that all KPC-Kp exhibited a low SNP rate of divergence, belonged to ST512 and shared similar antimicrobial resistance and porin gene patterns. Genetic analysis demonstrated that the first ceftazidime/avibactam-resistant KPC-Kp strain harboured a blaKPC-53 gene in a Tn4401 transposon moved from IncFII(K) to a 43 kb IncX3 plasmid, while a imipenem/cilastatin/relebactam-resistant strain exhibited two copies of the Tn4401 transposon in IncFII(K) and IncX3 plasmids, resulting in an increased blaKPC copy number. Of note, frequency analysis demonstrated that imipenem/cilastatin/relebactam-resistant KPC-Kp consisted of mixed subpopulations harbouring blaKPC-40 and blaKPC-53 alleles. CONCLUSIONS: Our results show the in vivo evolution of genetic rearrangement conferring resistance to imipenem/relebactam in a patient with KPC-Kp infection and treated with different ceftazidime/avibactam-based treatments. The rapid development of mutations and the high adaptability of its genome highlight the potential threat of KPC-Kp.

Successful Treatment of Bloodstream Infection due to a KPC-Producing Klebsiella Pneumoniae Resistant to Imipenem/Relebactam in a Hematological Patient.

Novel carbapenem-ß-lactamase inhibitor combination, imipenem/relebactam (IMI-REL), has been recently approved for treatment of infections with limited or no alternative treatment options. In this study, we described the emergence of the IMI-REL-resistance in a KPC-producing Klebsiella pneumoniae (KPC-Kp) strain collected from a hematological patient with no evidence of prior colonization. Interestingly, IMI-REL-resistance was associated with meropenem/vaborbactam (MER-VAB) cross-resistance but was not associated with cross-resistance to ceftazidime/avibactam (CAZ-AVI). Although treatment with CAZ-AVI and gentamicin completely eradicated the infection due KPC-Kp cross-resistance to IMI-REL and MER-VAB, the patient became colonized subsequently by KPC-Kp strains susceptible to IMI-REL and MER-VAB. Whole-genome sequencing performed by hybrid approach using Illumina and Oxford Nanopore platforms demonstrated that all KPC-Kp strains isolated from hematological patient belonged to the ST512 and were clonally related. Analysis of antimicrobial and porins genes demonstrated that cross-resistance to IMI-REL and MER-VAB was associated with increased blaKPC-3 copy number and truncated OmpK35 and OmpK36 with GD134-135 insertion. Phylogenetic analysis demonstrated that KPC-Kp cross-resistance to IMI-REL and MER-VAB was clonally related to a KPC-Kp resistant to IMI-REL as previously described, demonstrating the spread of this multidrug resistant clone in the hematological unit. In conclusion, the results presented in this study reported the emergence of cross-resistance to MER-VAB and IMI-REL in a KPC-Kp strain isolated from a hematological patient and highlight the potential development and diffusion of new multidrug resistance traits.

Prevalence of COVID-19-Associated Pulmonary Aspergillosis: Critical Review and Conclusions.

First reports of cases and case series of COVID-19-associated pulmonary aspergillosis (CAPA) emerged during the first months of the pandemic. Prevalence rates varied widely due to the fact that CAPA was, and still remains, challenging to diagnose in patients with COVID-19-associated acute respiratory failure (ARF). The clinical picture and radiological findings of CAPA are unspecific and can resemble those of severe COVID-19. Hence, mycological evidence became a key component in establishing a diagnosis. However, blood tests lack sensitivity in early treatable phases of CAPA and once positive, mortality has been shown to exceed 80% despite systemic antifungal therapy. The primarily airway invasive growth in non-neutropenic patients and the late occurrence of angioinvasion in the course of disease may mainly account for these diagnostic obstacles. Testing of bronchoalveolar lavage (BAL) is therefore crucial in the diagnostic process, but was rarely performed during the early phase of the pandemic, which potentially interfered with the accuracy of reported prevalence. Current guidelines recommend treatment of CAPA during its early airway invasive phase, which may result in some overtreatment (i.e., treatment in patients that may not develop angioinvasive infection) and adverse drug events, yet there is no viable alternative approach. Timely treatment of cases needs to be ensured for patients with mycological evidence of CAPA in the lower respiratory tract given the independent contribution of CAPA to devastating mortality rates of around 50% that have been shown in multiple studies. Here, we review the evolution of reported CAPA prevalence and the role of CAPA as an important opportunistic infection affecting COVID-19 patients in intensive care units (ICUs).

Clinical consequences of very major errors with semi-automated testing systems for antimicrobial susceptibility of carbapenem-resistant Enterobacterales.

OBJECTIVES: In this study we investigated the rate of susceptibility testing discrepancies between semi-automated and reference systems with carbapenem-resistant Enterobacterales (CRE) and the impact of alleged errors by semi-automated systems on guiding targeted therapy for CRE bloodstream infection (BSI). METHODS: This was a multicentre, retrospective study enrolling patients with monomicrobial BSI caused by CRE from January 2013 to December 2016. Nonduplicate isolates from index blood cultures tested locally with semi-automated systems were centralized at a referral laboratory and retested with a reference broth microdilution or agar dilution method. RESULTS: We enrolled 366 patients with CRE-BSI; 220 (60%) were male, and the median age was 67 years (interquartile range, 54-76 years). When compared with the results of the reference methods, those of the semi-automated systems exhibited variable rates of very major errors (VMEs; i.e. false susceptibilities) and major errors (MEs; i.e. false resistances). The highest rates of VMEs were observed with fosfomycin (14%) and colistin (13.9%), and the highest rates of MEs were observed with gentamicin (21%), fosfomycin (7.7%), and tigecycline (34%). Overall, VMEs and MEs led clinicians to prescribe or confirm ineffective therapy in 25 of 341 patients (7%). Receipt of ineffective therapy supported by a misleading susceptibility test was associated with higher 30-day mortality rates by Kaplan-Meier survival curves rates compared with receipt of active therapy (56% vs. 26%; p = 0.002), and the difference was confirmed after adjustment for confounders in a Cox regression model (adjusted hazard ratio: 2.91; 95% CI, 1.62-5.22; p < 0.001). DISCUSSION: MEs and VMEs were relatively common with semi-automated susceptibility testing systems. VMEs were associated with inappropriate use of antibiotics and poorer outcomes.