Exosomal miR-17-5p, miR-146a-3p, and miR-223-3p Correlate with Radiologic Sequelae in Survivors of COVID-19-Related Acute Respiratory Distress Syndrome.

We investigated the association between circulating microRNAs (miRNAs) potentially involved in the lung inflammatory process and fibrosis development among COVID-19-related acute respiratory distress syndrome (ARDS) survivors. At 4 ± 2 months from clinical recovery, COVID-19-related ARDS survivors matched for age, sex, and clinical characteristics underwent chest high-resolution computerized tomography (HRCT) and were selected based on imaging pattern evolution into fully recovered (N = normal), pulmonary opacities (PO) and fibrosis-like lesions (FL). Based on the previous literature, we performed plasma miRNA profiling of exosomal miRNAs belonging to the NLRP3-inflammasome platform with validated (miR-17-5p, miR-223-3p) and putative targets (miR-146a-5p), miRNAs involved in the post-transcriptional regulation of acute phase cytokines (miR128-3p, miR3168, miR125b-2-3p, miR106a-5p), miRNAs belonging to the NLRP4-inflammasome platform (miR-141-3p) and miRNAs related to post-transcriptional regulation of the fibrosis process (miR-21-5p). miR-17-5p, miR-223-3p, and miR-146a-5p were significantly down-regulated in patients with FL when compared to patients with PO. miR-146a-5p was also down-regulated in patients with FL than in N. The expression of the remaining miRNAs did not differ by group. In patients with long-term pulmonary radiological sequelae following COVID-19-related ARDS, a down-regulation of miR-17-5p, miR-146a-3p, and miR-223-3p correlated to fibrosis development in patients showing persistent hyper-reactivity to inflammatory stimulation. Our results support the hypothesis that NLRP3-Inflammasome could be implicated in the process of fibrotic evolution of COVID-19-associated ARDS.

Prosthetic joint infection diagnosis applying the three-level European Bone and Joint Infection Society (EBJIS) approach.

Sensitive and specific tests for the diagnosis of prosthetic joint infection (PJI) are lacking. The aim of this study was to report clinical and microbiological findings of consecutive patients diagnosed with PJI at the University Hospital of Perugia, Perugia, Italy, and to validate these diagnoses utilizing the European Bone and Joint Infection Society (EBJIS) three-level diagnostic approach from 2021. Patients with a PJI diagnosis were included in this study and examined retrospectively. Overall, 133 patients were diagnosed with PJI: mean age 72 years, 54.9% female, and 55.6% with more than one comorbidity. The most frequent involved joints were hip 47% and knee 42%. Aetiology was identified in 88/133 (66.2%): staphylococci resulted the most frequent microorganisms and over 80% (45/54) resulted rifampin susceptible. Applying the EBJIS approach, PJI diagnosis resulted: confirmed in 101 (75.9%), likely in 25 (18.8%), and unlikely in 7 (5.3%). Likely PJIs aetiology was Staphylococcus aureus 11/25, coagulase-negative staphylococci 8/25, Streptococcus agalactiae 3/25, viridans group streptococci 2/25, and Pseudomonas aeruginosa 1/25. No statistically significant differences were detected among the three diagnosis groups with regard to clinical characteristics with the exception of a higher number of confirmed PJIs occurring < 3 months after implantation. The logistic regression analysis did not disclose any independent predictor of confirmed PJIs. We recommend using all the diagnostic tests available to approach PJI diagnosis, and suggest caution before rejecting PJI diagnosis in the presence of highly virulent microorganisms from a single sample, in patients without sinus tract, and in those receiving antimicrobial at the time microbiologic samples are collected. Study approved by Umbrian Regional Ethical Committee, Perugia, Italy, Prot. N. 23,124/21/ON of 10.27.2021.

Risk Factors and Outcomes of Endocarditis Due to Non-HACEK Gram-Negative Bacilli: Data from the Prospective Multicenter Italian Endocarditis Study Cohort.

The objective of this study was to investigate predisposing factors and outcomes of infective endocarditis (IE) caused by non-HACEK Gram-negative bacilli (GNB) in a contemporary multicenter cohort. Patients with IE due to GNB, prospectively observed in 26 Italian centers from 2004 to 2011, were analyzed. Using a case-control design, each case was compared to three age- and sex-matched controls with IE due to other etiologies. Logistic regression was performed to identify risk factors for IE due to GNB. Factors associated with early and late mortality were assessed by Cox regression analysis. The study group comprised 58 patients with IE due to GNB. We found that Escherichia coli was the most common pathogen, followed by Pseudomonas aeruginosa and Klebsiella pneumoniae The genitourinary tract as a source of infection (odds ratio [OR], 13.59; 95% confidence interval [CI], 4.63 to 39.93; P < 0.001), immunosuppression (OR, 5.16; 95% CI, 1.60 to 16.24; P = 0.006), and the presence of a cardiac implantable electronic device (CIED) (OR, 3.57; 95% CI, 1.55 to 8.20; P = 0.003) were factors independently associated with IE due to GNB. In-hospital mortality was 13.8%, and mortality rose to 30.6% at 1 year. A multidrug-resistant (MDR) etiology was associated with in-hospital mortality (hazard ratio [HR], 21.849; 95% CI, 2.672 to 178.683; P = 0.004) and 1-year mortality (HR, 4.408; 95% CI, 1.581 to 12.287; P = 0.005). We conclude that the presence of a genitourinary focus, immunosuppressive therapy, and an indwelling CIED are factors associated with IE due to GNB. MDR etiology is the major determinant of in-hospital and long-term mortality.

Current features of infective endocarditis in persons on hemodialysis: a prevalence study with case control design from the prospective multicenter SEI cohort.

PURPOSE: Persons on hemodialysis (HD) are at high risk of infective endocarditis (IE). In non-comparative retrospective studies, a higher rate of mortality was reported in IE on HD. We assessed risk factors, clinical characteristics, and outcomes of IE in HD. METHODS: This was a prevalence study with a case control methodology on a set of data from the prospectively followed cohort of the Studio Endocarditi Italiano (SEI), conducted between 2004 and 2011. Included were 42 consecutive cases of IE HD subjects and 126 controls not on HD, matched for age, sex, type of IE, and heart side involved. Clinical, echocardiographic, microbiological features, and disease complications and therapeutic modalities were assessed. RESULTS: HD patients were more often diabetics (42.9 vs 18.2 % in no-HD; p = 0.007) and immune-suppressed (16.7 vs 3.2 %; p = 0.02), and had a higher rate of predisposing cardiac conditions (45 vs 25 %; p = 0.031). A higher prevalence of health care-related acquisition and a shorter diagnostic delay was observed in IE on HD, that was more likely to be caused by staphylococci and less by streptococci (p < 0.002). Cardiac surgery was performed in 38 % of HD patients and 36.5 % of no-HD patients (p = 0.856). Complications were similar and in-hospital mortality did not differ significantly (26.2 % in HD vs 15.9 % in no-HD; p = 0.168). CONCLUSIONS: IE in persons on HD is characterized by distinctive clinical features, including a higher prevalence of some important comorbidities. Inconsistent with prior studies, we could not confirm a higher rate of complications and mortality in HD patients with IE.

First Case of Trichoderma longibrachiatum CIED (Cardiac Implantable Electronic Device)-Associated Endocarditis in a Non-immunocompromised Host: Biofilm Removal and Diagnostic Problems in the Light of the Current Literature.

BACKGROUND: Trichoderma species are saprophytic filamentous fungi producing localized and invasive infections that are cause of morbidity and mortality, especially in immunocompromised patients, causing up to 53% mortality. Non-immunocompromised patients, undergoing continuous ambulatory peritoneal dialysis, are other targets of this fungus. Current molecular diagnostic tools, based on the barcode marker ITS, fail to discriminate these fungi at the species level, further increasing the difficulty associated with these infections and their generally poor prognosis. CASE REPORT: We report on the first case of endocarditis infection caused by Trichoderma longibrachiatum in a 30-year-old man. This patient underwent the implantation of an implantable cardioverter defibrillator in 2006, replaced in 2012. Two years later, the patient developed fever, treated successfully with amoxicillin followed by ciprofloxacin, but an echocardiogram showed large vegetation onto the ventricular lead. After CIED extraction, the patient had high-grade fever. The culturing of the catheter tip was positive only in samples deriving from sonication according to the 2014 ESCMID guidelines, whereas the simple washing failed to remove the biofilm cells from the plastic surface. Subsequent molecular (ITS sequencing) and microbiological (macromorphology) analyses showed that the vegetation was due to T. longibrachiatum. CONCLUSIONS: This report showed that T. longibrachiatum is an effective threat and that sonication is necessary for the culturing of vegetations from plastic surfaces. Limitations of the current barcode marker ITS, and the long procedures required by a multistep approach, call for the development of rapid monophasic tests.

Predicting the occurrence of embolic events: an analysis of 1456 episodes of infective endocarditis from the Italian Study on Endocarditis (SEI).

BACKGROUND: Embolic events are a major cause of morbidity and mortality in patients with infective endocarditis. We analyzed the database of the prospective cohort study SEI in order to identify factors associated with the occurrence of embolic events and to develop a scoring system for the assessment of the risk of embolism. METHODS: We retrospectively analyzed 1456 episodes of infective endocarditis from the multicenter study SEI. Predictors of embolism were identified. Risk factors identified at multivariate analysis as predictive of embolism in left-sided endocarditis, were used for the development of a risk score: 1 point was assigned to each risk factor (total risk score range: minimum 0 points; maximum 2 points). Three categories were defined by the score: low (0 points), intermediate (1 point), or high risk (2 points); the probability of embolic events per risk category was calculated for each day on treatment (day 0 through day 30). RESULTS: There were 499 episodes of infective endocarditis (34%) that were complicated by ≥ 1 embolic event. Most embolic events occurred early in the clinical course (first week of therapy: 15.5 episodes per 1000 patient days; second week: 3.7 episodes per 1000 patient days). In the total cohort, the factors associated with the occurrence of embolism at multivariate analysis were prosthetic valve localization (odds ratio, 1.84), right-sided endocarditis (odds ratio, 3.93), Staphylococcus aureus etiology (odds ratio, 2.23) and vegetation size ≥ 13 mm (odds ratio, 1.86). In left-sided endocarditis, Staphylococcus aureus etiology (odds ratio, 2.1) and vegetation size ≥ 13 mm (odds ratio, 2.1) were independently associated with embolic events; the 30-day cumulative incidence of embolism varied with risk score category (low risk, 12%; intermediate risk, 25%; high risk, 38%; p < 0.001). CONCLUSIONS: Staphylococcus aureus etiology and vegetation size are associated with an increased risk of embolism. In left-sided endocarditis, a simple scoring system, which combines etiology and vegetation size with time on antimicrobials, might contribute to a better assessment of the risk of embolism, and to a more individualized analysis of indications and contraindications for early surgery.

Syphilis as a diagnosis of liver abnormalities in HIV.

In order to investigate syphilitic liver involvement in HIV-infected patients, a single-centre retrospective study of a cohort of HIV-infected patients with syphilis was performed at the Infectious Diseases Clinic of Perugia, Italy, between December 2002 and March 2010. Fifty HIV-infected patients were identified with syphilis plus baseline and follow-up liver tests. The following syphilis diagnoses were recorded: 19 secondary (38%), 26 latent (52%), and 5 tertiary/neurosyphilis (12%). Syphilitic hepatitis was found in 5/50 (10%) patients. This finding supports the importance of including syphilis in the differential diagnosis of liver enzyme abnormalities in HIV-infected patients. An early diagnosis of syphilitic hepatitis can lead to rapid normalization of liver function following appropriate therapy, prevents the progression of syphilis, and limits the further spread of sexually transmitted diseases, including HIV.

Stroke in patients with tuberculous meningitis in a low TB endemic country: an increasing medical emergency?

Stroke due to brain vascular disease is a serious complication of tuberculous meningitis (TBM). This study evaluated the frequency, clinical characteristics, risk factors and outcomes of patients with TBM complicated by stroke admitted to the Infectious Disease Clinic, University of Perugia Hospital, Italy from 1971 to 2010. Over four decades, 419 patients were admitted with tuberculosis, of these 30 (7.1%) were diagnosed with TBM: 20 definite, one probable and nine possible. Twenty-six were evaluable for stroke and six (23%) had stroke. The latter six had advanced stages of meningitis, two tested HIV positive, three HIV negative and in one HIV was not performed. Of seven patients without stroke tested for HIV, only one resulted positive. No differences were found regarding CSF cell count, sugar, protein, microscopy or growth of Mycobacterium tuberculosis among patients with or without stroke. The overall survival rate at discharge was 83% in patients with stroke and 95% in those without stroke. It was found that stroke can be frequent among patients with TBM and the presence of HIV infection might be associated with a higher rate of stroke. Further research is needed on these findings, especially in low TB endemic countries.

Synergistic Activity of Remdesivir-Nirmatrelvir Combination on a SARS-CoV-2 In Vitro Model and a Case Report.

BACKGROUND: This study aims to investigate the activity of the remdesivir-nirmatrelvir combination against Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) and to report a case of Coronavirus Disease 2019 (COVID-19) cured with this combination. METHODS: A Vero E6 cell-based infection assay was used to investigate the in vitro activity of the remdesivir-nirmatrelvir combination. The SARS-CoV-2 strains tested were 20A.EU1, BA.1 and BA.5. After incubation, a viability assay was performed. The supernatants were collected and used for viral titration. The Highest Single Agent (HSA) reference model was calculated. An HSA score >10 is considered synergic. RESULTS: Remdesivir and nirmatrelvir showed synergistic activity at 48 and 72 h, with an HSA score of 52.8 and 28.6, respectively (p < 0.0001). These data were confirmed by performing supernatant titration and against the omicron variants: the combination reduced the viral titer better than the more active compound alone. An immunocompromised patient with prolonged and critical COVID-19 was successfully treated with remdesivir, nirmatrelvir/ritonavir, tixagevimab/cilgavimab and dexamethasone, with an excellent clinical-radiological response. However, she required further off-label prolonged therapy with nirmatrelvir/ritonavir until she tested negative. CONCLUSIONS: Remdesivir-nirmatrelvir combination has synergic activity in vitro. This combination may have a role in immunosuppressed patients with severe COVID-19 and prolonged viral shedding.

Lingual tuberculosis: a rare disease in Western countries.

Here we report on two consecutive cases of tuberculosis in immunocompetent HIV-negative patients with lingual lesions. In both patients diagnosis was delayed. Disease progressed involving the lungs, lymph nodes and also the brain. Both patients are disease-free at 30 and 22 month follow-up respectively. Isolated Mycobacterium tuberculosis from these patients was multi-susceptible. Tuberculosis lesions of the oral cavity and brain are infrequently diagnosed in immunocompetent subjects from Western countries. Clinicians must take into greater consideration tuberculosis as a possible diagnosis when diagnosing chronic and/or recurrent lingual lesions even in the absence of pulmonary lesions.

Osteosynthesis-associated infection of the lower limbs by multidrug-resistant and extensively drug-resistant Gram-negative bacteria: a multicentre cohort study.

Purpose: The purpose of this study was the clinical and therapeutic assessment of lower-limb osteosynthesis-associated infection (OAI) by multidrug-resistant (MDR) and extensively drug-resistant (XDR) Gram-negative bacteria (GNB), which have been poorly studied to date. Methods: A prospective multicentre observational study was conducted on behalf of ESGIAI (the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) Study Group on Implant-Associated Infections). Factors associated with remission of the infection were evaluated by multivariate and Cox regression analysis for a 24-month follow-up period. Results: Patients ( n = 57 ) had a history of trauma (87.7 %), tumour resection (7 %) and other bone lesions (5.3 %). Pathogens included Escherichia coli ( n = 16 ), Pseudomonas aeruginosa ( n = 14 ; XDR 50 %), Klebsiella spp. ( n = 7 ), Enterobacter spp. ( n = 9 ), Acinetobacter spp. ( n = 5 ), Proteus mirabilis ( n = 3 ), Serratia marcescens ( n = 2 ) and Stenotrophomonas maltophilia ( n = 1 ). The prevalence of ESBL (extended-spectrum ß -lactamase), fluoroquinolone and carbapenem resistance were 71.9 %, 59.6 % and 17.5 % respectively. Most patients ( n = 37 ; 64.9 %) were treated with a combination including carbapenems ( n = 32 ) and colistin ( n = 11 ) for a mean of 63.3 d. Implant retention with debridement occurred in early OAI (66.7 %), whereas the infected device was removed in late OAI (70.4 %) ( p = 0.008 ). OAI remission was achieved in 29 cases (50.9 %). The type of surgery, antimicrobial resistance and duration of treatment did not significantly influence the outcome. Independent predictors of the failure to eradicate OAI were age > 60  years (hazard ratio, HR, of 3.875; 95 % confidence interval, CI95 %, of 1.540-9.752; p = 0.004 ) and multiple surgeries for OAI (HR of 2.822; CI95 % of 1.144-6.963; p = 0.024 ). Conclusions: Only half of the MDR/XDR GNB OAI cases treated by antimicrobials and surgery had a successful outcome. Advanced age and multiple surgeries hampered the eradication of OAI. Optimal therapeutic options remain a challenge.

A host signature based on TRAIL, IP-10, and CRP for reducing antibiotic overuse in children by differentiating bacterial from viral infections: a prospective, multicentre cohort study.

OBJECTIVES: Identifying infection aetiology is essential for appropriate antibiotic use. Previous studies have shown that a host-protein signature consisting of TNF-related apoptosis-induced ligand (TRAIL), interferon-γ-induced protein-10 (IP-10), and C-reactive protein (CRP) can accurately differentiate bacterial from viral infections. METHODS: This prospective, multicentre cohort study, entitled AutoPilot-Dx, aimed to validate signature performance and to estimate its potential impact on antibiotic use across a broad paediatric population (>90 days to 18 years) with respiratory tract infections, or fever without source, at emergency departments and wards in Italy and Germany. Infection aetiology was adjudicated by experts based on clinical and laboratory investigations, including multiplex PCR and follow-up data. RESULTS: In total, 1140 patients were recruited (February 2017-December 2018), of which 1008 met the eligibility criteria (mean age 3.5 years, 41.9% female). Viral and bacterial infections were adjudicated for 628 (85.8%) and 104 (14.2%) children, respectively; 276 patients were assigned an indeterminate reference standard outcome. For the 732 children with reference standard aetiology, the signature discriminated bacterial from viral infections with a sensitivity of 93.7% (95%CI 88.7-98.7), a specificity of 94.2% (92.2-96.1), positive predictive value of 73.0% (65.0-81.0), and negative predictive value of 98.9% (98.0-99.8); in 9.8% the test results were equivocal. The signature performed consistently across different patient subgroups and detected bacterial immune responses in viral PCR-positive patients. CONCLUSIONS: The findings validate the high diagnostic performance of the TRAIL/IP-10/CRP signature in a broad paediatric cohort, and support its potential to reduce antibiotic overuse in children with viral infections.

Bactericidal activity of oxacillin and glycopeptides against Staphylococcus aureus in patients with endocarditis: looking for a relationship between tolerance and outcome.

BACKGROUND: There is no clear relationship between in vitro bactericidal activity tests and clinical outcome. We studied bactericidal activity of oxacillin, vancomycin and teicoplanin against Staphylococcus aureus isolates in patients with endocarditis and then we sought to determine if there was a relationship between in vitro bactericidal activity and clinical outcome. METHODS: Minimal bacteriostatic and minimal bactericidal concentrations were determined for Staphylococcus aureus strains isolated from patients with endocarditis following standardized methods. Medical records were reviewed retrospectively to collect data on antimicrobial susceptibility at admission, antimicrobial therapy, need for surgery, embolic events and outcome. RESULTS AND DISCUSSION: Sixty-two Staphylococcus aureus strains were studied in 62 patients with endocarditis. Overall, 91.9% definite, 21% methicillin resistant and 72.6% cured. Surgery was performed in 32.3% and embolic events were documented in 64.5%. Tolerance to oxacillin and teicoplanin was more common than vancomycin tolerance among methicillin susceptible Staphylococcus aureus. Among methicillin resistant Staphylococcus aureus teicoplanin was shown to have a higher rate of tolerance than vancomycin. No statistically significant differences on clinical outcome between oxacillin tolerant and oxacillin non tolerant Staphylococcus aureus infections were observed. Tolerance to oxacillin did not adversely affect clinical outcomes of patients with methicillin susceptible Staphylococcus aureus endocarditis treated with a combination of antimicrobials including oxacillin. The cure rate was significantly lower among patients with methicillin resistant Staphylococcus aureus endocarditis. CONCLUSIONS: In vitro bactericidal test results were not valid predictors of clinical outcome. Physicians need to use additional parameters when treating patients with staphylococcal endocarditis.

Diagnosing tuberculosis in pregnancy: a case report.

A case of miliary tuberculosis complicated by deciduitis and sub-chorionitis in a pregnant woman manifesting also influenza A/H1N1v infection and urinary tract infection is reported. Diagnosis of tuberculosis was obtained before delivery by examining amniotic fluid for Mycobacterium tuberculosis. Even though maternal symptoms did not suggest TB, diagnosis was early enough to start effective treatment in both the mother and the neonate and prevent in-hospital M.tuberculosis diffusion. A high index of suspicion by health professionals is required to detect and manage tuberculosis in pregnancy and newborns in both the developed and developing word.

QuantiFERON-TB and tuberculin skin test in patients with active tuberculosis: the experience of a single medium-sized Italian University Hospital.

Interferon-γ releasing assays (IGRAs) are currently widely employed in the initial work up of Mycobacterium tuberculosis infection, as well as in suspected tuberculosis (TB). These assays are commonly utilized over the Tuberculin Skin Test (TST) in high resource and low TB burden settings, despite the unclear benefits shown in such contexts. The debate on the use of TST and IGRAs is of current interest also in Italy due to the increasing presence of immigrants from countries with a high incidence of TB and the rising attention of health care institutions to economic costs. The aim of this study was to compare QuantiFERON-TB (QFT) and TST results in active TB. We evaluated QFT results and TST reactions from 245 consecutive patients having both tests, registered among 411 patients admitted for TB at the Infectious Disease Clinic, Department of Medicine of the University of Perugia (Italy). We compared the rates of positive QFT and TST tests and noted no statistically significant differences overall or in relation to age, gender, HIV status and TB localization. Among foreign-born patients with confirmed TB, we observed a lower rate of positive TST results. The results of our study indicated that both QFT and TST can be used in the work up of TB having special attention when evaluating foreign-born patients.

Daptomycin-based aminoglycoside-sparing therapy for streptococcal endocarditis: a retrospective multicenter study.

Streptococci still represent common etiologic agents of infective endocarditis (IE). Although renal failure is frequently reported as an aminoglycoside-associated adverse event, last international guidelines recommend a beta-lactam/gentamicin combination therapy. We retrospectively evaluated the use of daptomycin-based aminoglycoside-sparing combination therapy for the treatment of streptococcal IE in seven referral hospitals in Italy. Retrospective, multicenter, observational study. All patients with streptococcal IE admitted from 2016 to 2018 were enrolled. Mortality and incidence of acute kidney injury (AKI) were compared between Group A (standard of care, SoC) and Group B (daptomycin-based aminoglycoside-sparing combination therapy). Fifty-four patients were enrolled, 33 in Group A and 21 in Group B. Mortality was 2/33 (6%) in Group A and 0 in Group B (p = 0.681); AKI incidence was 8/33 (24%) in Group A and 0 in Group B (p = 0.04). Daptomycin-based aminoglycoside-sparing combination therapy appears to be promising for the treatment of streptococcal endocarditis because of similar efficacy compared with SoC and significantly reduced incidence of AKI.

Improving the etiological diagnosis of osteoarticular infections with the commercial multiplex real-time polymerase chain reaction SeptiFast®.

Detection of etiological agents is pivotal for adequate therapy of osteoarticular bacterial infections. Culture often lacks sensitivity, especially in patients under antibiotic therapy. The present study investigates the potential clinical utility of the commercial multiplex real-time polymerase chain reaction SeptiFast® (SF) in the etiological diagnosis of osteoarticular infections. Results obtained from conventional culture and SF were compared in 86 osteoarticular specimens collected from patients with suspected infection. The number of specimens positive by SF (38/86, 44.18%) was significantly greater (P = 0.001) than that of specimens positive by culture (20/86, 23.25%). The sensitivity of SF was 48.71%, significantly higher than culture sensitivity (25.64%). Specificity was 100% for both tests. The overall diagnostic accuracy for SF was 53.48%, and that of culture was 32.55%. Even with the limitation of the low number of specimens, this study supports the usefulness of SF in the diagnosis of osteoarticular infections.

In vitro antibacterial activity of ceftazidime/avibactam in combination against planktonic and biofilm carbapenemase-producing Klebsiella pneumoniae isolated from blood.

OBJECTIVES: The aim of this study was to report on in vitro tests of antibacterial activity of ceftazidime/avibactam in combination against planktonic or biofilm KPC carbapenemase-producing Klebsiella pneumoniae (KPC-Kp), the rate of KPC-Kp blood isolates in University of Perugia Hospital over a 5-year period, and their antimicrobial susceptibility patterns. METHODS: The antibacterial activity of ceftazidime/avibactam in combination with other antimicrobials was assessed against planktonic and biofilm bacteria by Etest and checkerboard assay. A retrospective review of laboratory data was performed to evaluate the rate of KPC-Kp from blood samples and their antimicrobial susceptibility patterns. RESULTS: Between 2014 and 2019, 130/4241 (3.1%) KPC-Kp were identified from blood cultures. Their rate increased from 2.3% in 2014-2015 to 4.5% over the last 3 years. Overall, 4.6% (6/130) of KPC-Kp isolates were susceptible to meropenem, 65.4% (85/130) to colistin, 65.1% (84/129) to tigecycline, 34.6% (45/130) to amikacin, 36.2% (42/116) to gentamicin, 40.2% (39/97) to fosfomycin and 91.5% (65/71) to ceftazidime/avibactam. Five of six ceftazidime/avibactam-resistant KPC-Kp were isolated from patients not treated with ceftazidime/avibactam. Synergism was detected both by Etest and checkerboard assay for the combination of ceftazidime/avibactam plus meropenem against planktonic isolates, whilst lower bactericidal activity was observed in biofilm KPC-Kp isolates. CONCLUSIONS: Our in vitro data suggest that the combination of ceftazidime/avibactam plus meropenem has a synergistic antibacterial activity against planktonic bacteria, whilst a lower activity was detected against biofilm, suggesting worse clinical outcomes whenever biofilm infections are present. Further analyses are required to confirm these results before extending them to clinical practice.

Procalcitonin, white blood cell count and C-reactive protein as predictors of S. aureus infection and mortality in infective endocarditis.

BACKGROUND: Infective endocarditis (IE) is characterized by high rates of in-hospital death, and Staphylococcus aureus infection predicts a worse prognosis. We aimed to assess if admission inflammatory biomarkers (white blood cell - WBC - count, C-reactive protein - CRP, and procalcitonin) are informative on microbiological etiology and short-term outcomes. METHODS: Data from 236 patients admitted for IE from January 2013 to June 2018 were retrieved from a multicenter registry. RESULTS: Fifty-two patients (22%) were infected by S. aureus. WBC, CRP and procalcitonin had area under the curve (AUC) values for S. aureus infection of 0.595, 0.675, and 0.727, respectively. Adding procalcitonin to WBC improved discrimination over WBC alone (p = 0.045), and procalcitonin predicted S. aureus infection independently from the other inflammatory biomarkers and patient characteristics. Patients with WBC ≥ 12,800/mm3, CRP ≥ 130 mg/L, and procalcitonin ≥ 1.7 ng/mL had an almost 20-fold higher risk of S. aureus infection than patients with all biomarkers < cut-offs. AUC values for in-hospital death were 0.702, 0.725 and 0.727 for the WBC, CRP, and procalcitonin, respectively. Among inflammatory biomarkers, WBC and procalcitonin independently predicted in-hospital death. Procalcitonin refined risk stratification when added to WBC, and to the combination of WBC and CRP. Patients with WBC ≥ 10,535/mm3, CRP ≥ 85 mg/dL, and procalcitonin ≥ 0.4 ng/mL had a 27-fold higher risk of in-hospital death than patients with all biomarkers < cut-offs. CONCLUSIONS: Among patients with IE, high levels of inflammatory biomarkers on admission, particularly procalcitonin, are associated with a higher likelihood of S. aureus infection, and a higher risk of in-hospital mortality.