Identification of hypermucoviscous Klebsiella pneumoniae K1, K2, K54 and K57 capsular serotypes by Raman spectroscopy

Antimicrobial resistance poses a significant challenge in modern medicine, affecting public health. Klebsiella pneumoniae infections compound this issue due to their broad range of infections and the emergence of multiple antibiotic resistance mechanisms. Efficient detection of its capsular serotypes is crucial for immediate patient treatment, epidemiological tracking and outbreak containment. Current methods have limitations that can delay interventions and increase the risk of morbidity and mortality. Raman spectroscopy is a promising alternative to identify capsular serotypes in hypermucoviscous K. pneumoniae isolates. It provides rapid and in situ measurements with minimal sample preparation. Moreover, its combination with machine learning tools demonstrates high accuracy and reproducibility. This study analyzed the viability of combining Raman spectroscopy with one-dimensional convolutional neural networks (1-D CNN) to classify four capsular serotypes of hypermucoviscous K. pneumoniae: K1, K2, K54 and K57. Our approach involved identifying the most relevant Raman features for classification to prevent overfitting in the training models. Simplifying the dataset to essential information maintains accuracy and reduces computational costs and training time. Capsular serotypes were classified with 96 % accuracy using less than 30 Raman features out of 2400 contained in each spectrum. To validate our methodology, we expanded the dataset to include both hypermucoviscous and non-mucoid isolates and distinguished between them. This resulted in an accuracy rate of 94 %. The results obtained have significant potential for practical healthcare applications, especially for enabling the prompt prescription of the appropriate antibiotic treatment against infections.

Novel risk loci for COVID-19 hospitalization among admixed American populations

The genetic basis of severe COVID-19 has been thoroughly studied, and many genetic risk factors shared between populations have been identified. However, reduced sample sizes from non-European groups have limited the discovery of population-specific common risk loci. In this second study nested in the SCOURGE consortium, we conducted a genome-wide association study (GWAS) for COVID-19 hospitalization in admixed Americans, comprising a total of 4702 hospitalized cases recruited by SCOURGE and seven other participating studies in the COVID-19 Host Genetic Initiative. We identified four genome-wide significant associations, two of which constitute novel loci and were first discovered in Latin American populations (BAZ2B and DDIAS). A trans-ethnic meta-analysis revealed another novel cross-population risk locus in CREBBP. Finally, we assessed the performance of a cross-ancestry polygenic risk score in the SCOURGE admixed American cohort. This study constitutes the largest GWAS for COVID-19 hospitalization in admixed Latin Americans conducted to date. This allowed to reveal novel risk loci and emphasize the need of considering the diversity of populations in genomic research.

Risk factors and clinical impact of multidrug resistance in healthcare-associated bacteraemic urinary tract infections: a post-hoc analysis of a multicentre prospective cohort in Spain

BACKGROUND

The global burden associated with antimicrobial resistance is of increasing concern.

AIM

To evaluate risk factors associated with multidrug-resistant (MDR) infection and its clinical impact in a cohort of patients with healthcare-associated bacteraemic urinary tract infections (BUTIs).

METHODS

This was a prospective, multicentre, post-hoc analysis of patients with healthcare-associated-BUTI (ITUBRAS-2). The primary outcome was MDR profile. Secondary outcomes were clinical response (at 48-72 h and at hospital discharge) and length of hospital stay from onset of BUTI. Logistic regression was used to evaluate variables associated with MDR profile and clinical response. Length of hospital stay was evaluated using multivariate median regression.

FINDINGS

In all, 443 episodes were included, of which 271 (61.17%) were classified as expressing an MDR profile. In univariate analysis, MDR profile was associated with E. coli episodes (odds ratio (OR): 3.13; 95% confidence interval (CI): 2.11-4.69, P < 0.001) and the extensively drug-resistant (XDR) pattern with P. aeruginosa aetiology (7.84; 2.37-25.95; P = 0.001). MDR was independently associated with prior use of fluoroquinolones (adjusted OR: 2.43; 95% CI: 1.25-4.69), cephalosporins (2.14; 1.35-3.41), and imipenem or meropenem (2.08; 1.03-4.20) but not with prior ertapenem. In terms of outcomes, MDR profile was not associated with lower frequency of clinical cure, but was associated with longer hospital stay.

CONCLUSION

MDR profile was independently associated with prior use of fluoroquinolones, cephalosporins, imipenem, and meropenem, but not with prior ertapenem. MDR-BUTI episodes were not associated with worse clinical cure, although they were independently associated with longer duration of hospital stay.

Management of cytomegalovirus in adult solid organ transplant patients: GESITRA-IC-SEIMC, CIBERINFEC, and SET recommendations update

Cytomegalovirus (CMV) infection remains a significant challenge in solid organ transplantation (SOT). The last international consensus guidelines on the management of CMV in SOT were published in 2018, highlighting the need for revision to incorporate recent advances, notably in cell-mediated immunity monitoring, which could alter the current standard of care. A working group including members from the Group for the Study of Infection in Transplantation and the Immunocompromised Host (GESITRA-IC) of the Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC) and the Spanish Society of Transplantation (SET), developed consensus-based recommendations for managing CMV infection in SOT recipients. Recommendations were classified based on evidence strength and quality using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. The final recommendations were endorsed through a consensus meeting and approved by the expert panel.

Within-host transition to GES-55 during a GES-6-producing Serratia marcescens outbreak: Emergence of ceftazidime-avibactam resistance and increased susceptibility to carbapenems

OBJECTIVES

To describe the in vivo emergence of ceftazidime-avibactam resistance in GES-type carbapenemases and to characterize an unusual outbreak of GES-6-producing Serratia marcescens during the COVID-19 pandemic in Spain.

METHODS

Retrospective study to describe a GES-CPSM outbreak based on whole genome sequencing and antimicrobial susceptibility testing (AST). Transferability of blaGES-carrying plasmid was assessed by conjugation experiments.

RESULTS

In December 2020, we identified a cluster of S. marcescens harbouring blaGES-6 involving 9 patients. Whole-genome sequence analysis revealed a clonal relationship (≤3 SNPs) between the first isolates identified in each of the evolved patients and environmental samples with GES-CPSM detection. Plasmid analysis showed that the blaGES-6 gene was located in an IncQ3-type plasmid. Triparental mating experiments using a helper plasmid demonstrated mobilization of the blaGES-6-carrying plasmid. Our results also demonstrate within-host evolution in S. marcescens isolates, leading to a transition from blaGES-6 to the new blaGES-55, caused by the P162S mutation, in a subsequent infection in one of the affected patients. In blaGES-55 we identified emergence of ceftazidime-avibactam resistance along with an increase of carbapenems susceptibility. This patient had been treated with a 14-day course of ceftazidime-avibactam. AST of the transformants bearing blaGES-6 and blaGES-55 plasmids, confirmed susceptibility variation affecting ceftazidime-avibactam and carbapenems.

CONCLUSIONS

We report an unusual outbreak of GES-6 whose incidence is becoming increasing. Transition from GES-6 to GES-55 may readily occur in vivo leading to ceftazidime-avibactam resistance, which brings to the fore the critical need for developing more accurate diagnosis tools for detection of GES β-lactamases and optimise the use of antimicrobials.

Progression of subclinical cardiovascular disease in patients with HIV

OBJECTIVE

Human immunodeficiency virus (HIV) infected patients are at increased risk of cardiovascular disease (CVD). Multidetector computed tomography (MDCT) stratifies cardiovascular risk in asymptomatic patients with subclinical atherosclerosis. The aim of this study was to determine the ability of MCTD and clinical and laboratory parameters to assess subclinical CVD progression in HIV patients.

METHODS

Prospective longitudinal cohort study of patients with at least 10 years of HIV infection and 5 years of antiretroviral therapy history, low cardiovascular risk and monitored for 6 years (2015-2021). All patients underwent clinical assessment, blood analysis, carotid ultrasound, and gated MDCT in 2015 and 2021.

RESULTS

Sixty-three patients (63.5% male) with a mean age of 49.9 years (standard deviation [SD], 10.5) were included in 2015; 63 of them were followed until 2021. Comparing the results from 2015 with those from 2021, Systematic Coronary Risk Estimation-2 (SCORE2) was 2.9% (SD, 2.1) vs. 4.4% (SD,3.1); Multi-Ethnic Study of Atherosclerosis score (MESA risk) was 3.4 (SD 5.8) vs. 6.0 (SD 8.6); coronary artery calcification CAC) score >100 was 11.1% vs. 25.4% (P < 0.05); and 11% vs. 27% had carotid plaques (P = 0.03).

CONCLUSIONS

After six years of follow-up, an increase in SCORE2, carotid plaques, CAC scoring and MESA risk was observed. MDCT findings, along with other clinical and laboratory parameters, could play an important role as a marker of CVD progression in the evaluation of patients with HIV and low cardiovascular risk.

Infective endocarditis in HIV-infected patients. Analysis of a national cohort

BACKGROUND

There is limited recent evidence about infective endocarditis (IE) in HIV-infected patients. Our aim was to compare IE according to HIV infection presence.

METHODS

Consecutive inclusion of IE patients at 46 Spanish hospitals between 2008 and 2021.

RESULTS

From 5667 patients, 99 were HIV-infected (1·7%; 50 intravenous drugs users). Compared to patients without HIV, HIV-infected patients were more frequently male (84% vs. 67%), had younger median age (46 vs. 69 years), and less comorbidities, except liver disease (52% vs. 9%) and intravenous drug use (51% vs. 1%). They had more common tricuspid location (36% vs. 5%) and community-acquired IE (82% vs. 63%), vascular (29% vs. 17%) and cutaneous (22% vs. 7%) foci of infection, and Staphylococcus aureus aetiology (46% vs. 22%). Vegetations (84% vs. 72%), vascular phenomena (17% vs. 9%), splenomegaly (30% vs. 11%), and embolisation (41% vs 21%) were also more common. Surgical indication and surgery were less frequent in HIV-infected patients (54% vs 67%, 28% vs 47%, respectively). Median CD4 count in HIV-infected patients was 318 cells/mm3. In-hospital mortality (23% vs. 26%) and one-year mortality (25% vs. 32%) were similar in both groups. HIV infection was not independently associated with in-hospital (odds ratio 1·1, 95% CI 0·6-1·9) nor one-year mortality (hazard ratio 0·8, 95% CI 0·4-1·3).

CONCLUSIONS

In the combined antiretroviral therapy era, less than 2% of IE patients have HIV infection. HIV-infected patients have a different clinical profile than those without HIV, but the presence of HIV does not seem to impact on IE prognosis.

Isavuconazole Versus Voriconazole as the First-line Therapy for Solid Organ Transplant Recipients With Invasive Aspergillosis: Comparative Analysis of 2 Multicenter Cohort Studies

BACKGROUND

Isavuconazole (ISA) and voriconazole (VORI) are recommended as the first-line treatment for invasive aspergillosis (IA). Despite theoretical advantages of ISA, both triazole agents have not been compared in solid organ transplant recipients.

METHODS

We performed a post hoc analysis of 2 retrospective multicenter cohorts of solid organ transplant recipients with invasive fungal disease (the SOTIS [Solid Organ Transplantation and ISavuconazole] and DiasperSOT [DIagnosis of ASPERgillosis in Solid Organ Transplantation] studies). We selected adult patients with proven/probable IA that were treated for ≥48 h with ISA (n = 57) or VORI (n = 77) as first-line therapy, either in monotherapy or combination regimen. The primary outcome was the rate of clinical response at 12 wk from the initiation of therapy. Secondary outcomes comprised 12-wk all-cause and IA-attributable mortality and the rates of treatment-emergent adverse events and premature treatment discontinuation.

RESULTS

Both groups were comparable in their demographics and major clinical and treatment-related variables. There were no differences in the rate of 12-wk clinical response between the ISA and VORI groups (59.6% versus 59.7%, respectively; odds ratio [OR], 0.99; 95% confidence interval [CI], 0.49-2.00). This result was confirmed after propensity score adjustment (OR, 0.81; 95% CI, 0.32-2.05) and matching (OR, 0.79; 95% CI, 0.31-2.04). All-cause and IA-attributable mortality were also similar. Patients in the ISA group were less likely to experience treatment-emergent adverse events (17.5% versus 37.7%; P = 0.011) and premature treatment discontinuation (8.8% versus 23.4%; P = 0.027).

CONCLUSIONS

Front-line treatment with ISA for posttransplant IA led to similar clinical outcomes than VORI, with better tolerability and higher treatment completion.

Impact of Intermediate Susceptibility to Penicillin on Antimicrobial Treatment and Outcomes of Endocarditis Caused by Viridans and Gallolyticus Group Streptococci

BACKGROUND

Evidence supporting combination treatment with a beta-lactam plus an aminoglycoside (C-BA) for endocarditis caused by viridans and gallolyticus group streptococci (VGS-GGS) with intermediate susceptibility to penicillin (PENI-I) is lacking. We assessed the clinical characteristics and outcomes of PEN-I VGS-GGS endocarditis and compared the effectiveness and safety of C-BA with third-generation cephalosporin monotherapy.

METHODS

Retrospective analysis of prospectively collected data of a cohort of definite endocarditis caused by penicillin-susceptible and PENI-I VGS-GGS (penicillin minimum inhibitory concentration ranging from 0.25 to 2 mg/L) between 2008 and 2018 in 40 Spanish hospitals. We compared cases treated with monotherapy or with C-BA and performed multivariable analyses of risk factors for in-hospital and 1-year mortality.

RESULTS

A total of 914 consecutive cases of definite endocarditis caused by VGS-GGS with complete or intermediate susceptibility to penicillin were included. A total of 688 (75.3%) were susceptible to penicillin and 226 (24.7%) were PENI-I. Monotherapy was used in 415 (45.4%) cases (cephalosporin in 331 cases) and 499 (54.6%) cases received C-BA. In-hospital mortality was 11.9%, and 190 (20.9%) patients developed acute kidney injury. Heart failure (odds ratio [OR]: 6.06; 95% confidence interval [CI]: 1.37-26.87; P = .018), central nervous system emboli (OR: 9.83; 95% CI: 2.17-44.49; P = .003) and intracardiac abscess (OR: 13.47; 95% CI: 2.24-81.08; P = .004) were independently associated with in-hospital mortality among PEN-I VGS-GGS cases, while monotherapy was not (OR: 1.01; 95% CI: .26-3.96; P = .982).

CONCLUSIONS

Our findings support the use of cephalosporin monotherapy in PEN-I VGS-GGS endocarditis in order to avoid nephrotoxicity without adversely affecting patient outcomes.

Automatic classification of Candida species using Raman spectroscopy and machine learning

One of the problems that most affect hospitals is infections by pathogenic microorganisms. Rapid identification and adequate, timely treatment can avoid fatal consequences and the development of antibiotic resistance, so it is crucial to use fast, reliable, and not too laborious techniques to obtain quick results. Raman spectroscopy has proven to be a powerful tool for molecular analysis, meeting these requirements better than traditional techniques. In this work, we have used Raman spectroscopy combined with machine learning algorithms to explore the automatic identification of eleven species of the genus Candida, the most common cause of fungal infections worldwide. The Raman spectra were obtained from more than 220 different measurements of dried drops from pure cultures of each Candida species using a Raman Confocal Microscope with a 532 nm laser excitation source. After developing a spectral preprocessing methodology, a study of the quality and variability of the measured spectra at the isolate and species level, and the spectral features contributing to inter-class variations, showed the potential to discriminate between those pathogenic yeasts. Several machine learning and deep learning algorithms were trained using hyperparameter optimization techniques to find the best possible classifier for this spectral data, in terms of accuracy and lowest possible overfitting. We found that a one-dimensional Convolutional Neural Network (1-D CNN) could achieve above 80 % overall accuracy for the eleven classes spectral dataset, with good generalization capabilities.

Efficacy of ceftazidime-avibactam in solid organ transplant recipients with bloodstream infections caused by carbapenemase-producing Klebsiella pneumoniae

We aimed to compare the efficacy of ceftazidime-avibactam (CAZ-AVI) versus the best available therapy (BAT) in solid organ transplant (SOT) recipients with bloodstream infection caused by carbapenemase-producing Klebsiella pneumoniae (CPKP-BSI). A retrospective (2016-2021) observational cohort study was performed in 14 INCREMENT-SOT centers (ClinicalTrials.gov identifier: NCT02852902). Outcomes were 14-day and 30-day clinical success (complete resolution of attributable manifestations, adequate source control and negative follow-up blood cultures) and 30-day all-cause mortality. Multivariable logistic and Cox regression analyses adjusted for the propensity score to receive CAZ-AVI were constructed. Among 210 SOT recipients with CPKP-BSI, 149 received active primary therapy with CAZ-AVI (66/149) or BAT (83/149). Patients treated with CAZ-AVI had higher 14-day (80.7% versus 60.6%, P=0.011) and 30-day (83.1% versus 60.6%, P=0.004) clinical success and lower 30-day mortality (13.25% versus 27.3%, P=0.053) than those receiving BAT. In the adjusted analysis, CAZ-AVI increased the probability of 14-day (adjusted odds ratio [aOR]: 2.65; 95% confidence interval [95%CI]: 1.03-6.84, P=0.044) and 30-day clinical success (aOR: 3.14; 95%CI: 1.17-8.40; P=0.023). In contrast, CAZ-AVI therapy was not independently associated with 30-day mortality. In the CAZ-AVI group, combination therapy was not associated with better outcomes. In conclusion, CAZ-AVI may be considered a first-line treatment in SOT recipients with CPKP-BSI. SUMMARY SENTENCE: We retrospectively analyzed a cohort of 210 SOT recipients with bloodstream infection due to carbapenemase-producing Klebsiella pneumoniae. Among 149 patients receiving active therapy, 83 were treated with CAZ-AVI and 66 with other regimens. CAZ-AVI was an independent predictor of 14-day and 30-day clinical success.

Activity of imipenem/relebactam against Enterobacterales and Pseudomonas aeruginosa in Spain. SMART 2016-2020

OBJECTIVE

To determine susceptibility to the novel β-lactam/β-lactamase inhibitor combination imipenem/relebactam in clinical isolates recovered from intra-abdominal (IAI), urinary (UTI), respiratory (RTI) and bloodstream (BSI) infections in the SMART (Study for Monitoring Antimicrobial Resistance Trends) study in SPAIN during 2016 - 2020.

METHODS

Broth microdilution MICs for imipenem/relebactam and comparators were determined by a central laboratory against isolates of Enterobacterales and Pseudomonas aeruginosa. MICs were interpreted using EUCAST-2021 breakpoints.

RESULTS

In total, 5,210 Enterobacterales and 1,418 P. aeruginosa clinical isolates were analyzed. Imipenem/relebactam inhibited 98.8% of Enterobacterales. Distinguishing by source of infection susceptibility was 99.1% in BSI, 99.2% in IAI, 97.9% in RTI, and 99.2% in UTI. Of intensive care unit isolates (ICU) 97.4% were susceptible and of non-ICU isolates 99.2% were susceptible. In Enterobacterales, activity against Class A, Class B and Class D carbapenemases was 96.2%, 15.4% and 73.2%, respectively. In P. aeruginosa, imipenem/relebactam was active in 92.2% of isolates. By source of infection it was 94.8% in BSI, 92.9% in IAI, 91.7% in RTI, and 93.1% in UTI. An 88.7% of ICU isolates and 93.6% of non-ICU isolates were susceptible to imipenem/relebactam. Imipenem/relebactam remained active against P. aeruginosa ceftazidime-resistant (76.3%), cefepime-resistant (73.6%), imipenem-resistant (71.5%) and piperacillin-resistant (78.7%) isolates. Of all multidrug-resistant or difficult-to-treat resistance P. aeruginosa isolates, 75.1% and 46.2%, respectively, were susceptible to imipenem/relebactam.

CONCLUSIONS

Imipenem/relebactam showed high rates of susceptibility in Enterobacterales and P. aeruginosa isolates from different sources of infection as well as depending on patients' location (ICU or non-ICU scenarios).

Are GES carbapenemases underdiagnosed? An allelic discrimination assay for their accurate detection and differentiation

GES (Guiana Extended Spectrum) carbapenemases belong to "minor class A carbapenemases" and its prevalence could be underestimated due to the lack of specific tests. The aim of this study was to develop an easy PCR method to differentiate between GES β-lactamases with or without carbapenemase activity, based on an allelic discrimination system of SNPs that encode E104K and G170S mutations, without need of sequencing. Two pair of primers and Affinity Plus probes, labeled with different fluorophores; FAM/IBFQ and YAK/IBFQ, were designed for each one of the SNPs. This allelic discrimination assay allows to detect in real time the presence of all type of GES- β-lactamases, being able to differentiate between carbapenemases and extended-spectrum β-lactamase (ESBL), through a quick PCR test that avoid costly sequencing approaches and could help to decrease the current underdiagnosis of minor carbapenemases that scape of phenotypic screenings.

Heart transplantation as salvage treatment of intractable infective endocarditis

BACKGROUND

For infective endocarditis (IE) with extensive perivalvular lesions or end-stage cardiac failure, heart transplantation (HT) may be the last resort.

METHODS

We retrospectively collected all cases of HT for IE within the International Collaboration on Endocarditis (ICE) network.

RESULTS

Between 1991 and 2021, 20 patients (5 women, 15 men), median age 50 years [interquartile range, 29-61], underwent HT for IE in Spain (n = 9), France (n = 6), Switzerland (n = 2), Colombia, Croatia, and USA (n = 1). IE affected prosthetic (n = 10), and native valves (n = 10), primarily aortic (n = 11) and mitral (n = 6). The main pathogens were oral streptococci (n = 8), Staphylococcus aureus (n = 5), and Enterococcus faecalis (n = 2). The major complications included heart failure (n = 18), peri-annular abscess (n = 10), and prosthetic valve dehiscence (n = 4). Eighteen patients had previous cardiac surgery for this episode of IE, and four were on circulatory support before HT (left ventricular assist-device and extra-corporeal membrane oxygenation, 2 patients each). The median time interval between first symptoms of IE and HT was 44.5 days [22-91.5]. The main post-HT complication was acute rejection (n = 6). Seven patients died (35%), four during the first month post-HT. Thirteen (81%) of the 16 patients discharged from the hospital survived with a median follow-up of 35.5 months [4-96.5] after HT, and no relapse of IE.

CONCLUSIONS

IE is not an absolute contraindication for HT: Our case series and the literature review support that HT may be considered as a salvage treatment in highly-selected patients with intractable IE.

Risk Factors for Nontuberculous Mycobacteria Infections in Solid Organ Transplant Recipients: A Multinational Case-Control Study

BACKGROUND

Risk factors for nontuberculous mycobacteria (NTM) infections after solid organ transplant (SOT) are not well characterized. Here we aimed to describe these factors.

METHODS

Retrospective, multinational, 1:2 matched case-control study that included SOT recipients ≥12 years old diagnosed with NTM infection from 1 January 2008 to 31 December 2018. Controls were matched on transplanted organ, NTM treatment center, and post-transplant survival greater than or equal to the time to NTM diagnosis. Logistic regression on matched pairs was used to assess associations between risk factors and NTM infections.

RESULTS

Analyses included 85 cases and 169 controls (59% male, 88% White, median age at time of SOT of 54 years [interquartile range {IQR} 40-62]). NTM infection occurred in kidney (42%), lung (35%), heart and liver (11% each), and pancreas transplant recipients (1%). Median time from transplant to infection was 21.6 months (IQR 5.3-55.2). Most underlying comorbidities were evenly distributed between groups; however, cases were older at the time of NTM diagnosis, more frequently on systemic corticosteroids and had a lower lymphocyte count (all P < .05). In the multivariable model, older age at transplant (adjusted odds ratio [aOR] 1.04; 95 confidence interval [CI], 1.01-1.07), hospital admission within 90 days (aOR, 3.14; 95% CI, 1.41-6.98), receipt of antifungals (aOR, 5.35; 95% CI, 1.7-16.91), and lymphocyte-specific antibodies (aOR, 7.73; 95% CI, 1.07-56.14), were associated with NTM infection.

CONCLUSIONS

Risk of NTM infection in SOT recipients was associated with older age at SOT, prior hospital admission, receipt of antifungals or lymphocyte-specific antibodies. NTM infection should be considered in SOT patients with these risk factors.

Polygenic Innate Immunity Score to Predict the Risk of Cytomegalovirus Infection in CMV D+/R- Transplant Recipients. A Prospective Multicenter Cohort Study

Several genetic polymorphisms of the innate immune system have been described to increase the risk of cytomegalovirus (CMV) infection in transplant patients. The aim of this study was to assess the impact of a polygenic score to predict CMV infection and disease in high risk CMV transplant recipients (heart, liver, kidney or pancreas). On hundred and sixteen CMV-seronegative recipients of grafts from CMV-seropositive donors undergoing heart, liver, and kidney or pancreas transplantation from 7 centres were prospectively included for this purpose during a 2-year period. All recipients received 100-day prophylaxis with valganciclovir. CMV infection occurred in 61 patients (53%) at 163 median days from transplant, 33 asymptomatic replication (28%) and 28 CMV disease (24%). Eleven patients (9%) had recurrent CMV infection. Clinically and/or functionally relevant single nucleotide polymorphisms (SNPs) from TLR2, TLR3, TLR4, TLR7, TLR9, AIM2, MBL2, IL28, IFI16, MYD88, IRAK2 and IRAK4 were assessed by real time polymerase chain reaction (RT-PCR) or sequence-based typing (PCR-SBT). A polygenic score including the TLR4 (rs4986790/rs4986791), TLR9 (rs3775291), TLR3 (rs3775296), AIM2 (rs855873), TLR7 (rs179008), MBL (OO/OA/XAO), IFNL3/IL28B (rs12979860) and IFI16 (rs6940) SNPs was built based on the risk of CMV infection and disease. The CMV score predicted the risk of CMV disease with an AUC of the model of 0.68, with sensitivity and specificity of 64.3 and 71.6%, respectively. Even though further studies are needed to validate this score, its use would represent an effective model to develop more robust scores predicting the risk of CMV disease in donor/recipient mismatch (D+/R-) transplant recipients.

Novel genes and sex differences in COVID-19 severity

Here we describe the results of a genome-wide study conducted in 11 939 COVID-19 positive cases with an extensive clinical information that were recruited from 34 hospitals across Spain (SCOURGE consortium). In sex-disaggregated genome-wide association studies for COVID-19 hospitalization, genome-wide significance (p < 5x10-8) was crossed for variants in 3p21.31 and 21q22.11 loci only among males (p = 1.3x10-22 and p = 8.1x10-12, respectively), and for variants in 9q21.32 near TLE1 only among females (p = 4.4x10-8). In a second phase, results were combined with an independent Spanish cohort (1598 COVID-19 cases and 1068 population controls), revealing in the overall analysis two novel risk loci in 9p13.3 and 19q13.12, with fine-mapping prioritized variants functionally associated with AQP3 (p = 2.7x10-8) and ARHGAP33 (p = 1.3x10-8), respectively. The meta-analysis of both phases with four European studies stratified by sex from the Host Genetics Initiative confirmed the association of the 3p21.31 and 21q22.11 loci predominantly in males and replicated a recently reported variant in 11p13 (ELF5, p = 4.1x10-8). Six of the COVID-19 HGI discovered loci were replicated and an HGI-based genetic risk score predicted the severity strata in SCOURGE. We also found more SNP-heritability and larger heritability differences by age (<60 or ≥ 60 years) among males than among females. Parallel genome-wide screening of inbreeding depression in SCOURGE also showed an effect of homozygosity in COVID-19 hospitalization and severity and this effect was stronger among older males. In summary, new candidate genes for COVID-19 severity and evidence supporting genetic disparities among sexes are provided.

The poor accuracy of D-dimer for the diagnosis of prosthetic joint infection but its potential usefulness in early postoperative infections following revision arthroplasty for aseptic loosening

BACKGROUND

D-dimer was introduced in 2018 as an alternative biomarker for C-reactive protein (CRP) in the diagnostic of prosthetic joint infection (PJI) criteria of the Musculoskeletal Infection Society. We assessed the accuracy of plasma D-dimer for the diagnosis of early, delayed, and late PJI according to Infectious Diseases Society of America (IDSA) criteria, and whether persistently high levels of D-dimer in cases of aseptic loosening (AL) may be predictive of subsequent implant-related infection.

METHODS

A prospective study of a consecutive series of 187 revision arthroplasties was performed at a single institution. Septic (n = 39) and aseptic revisions (n = 141) were classified based on IDSA criteria. Preoperative assessment of CRP, erythrocyte sedimentation rate (ESR) and D-dimer was performed. Receiver operating curves were used to determine maximum sensitivity and specificity of the biomarkers. The natural progress of D-dimer for AL cases was followed up either until the date of implant-related infection at any time during the first year or 1 year after revision in patients without failure. Clinical outcomes for those AL cases included infection-related failure that required a new surgery or need for antibiotic suppression.

RESULTS

Preoperative D-dimer level was significantly higher in PJI cases than in AL cases (p = 0.000). The optimal threshold of D-dimer for the diagnosis of PJI was 1167 ng/mL. For overall diagnosis of PJI, C-reactive protein (CRP) achieved the highest sensitivity (84.6%), followed by erythrocyte sedimentation rate (ESR) and D-dimer (82% and 71.8%, respectively). Plasma D-dimer sensitivity was lower for all PJI types. When combinations of 2 tests were studied, the combined use of ESR and CRP achieved the best accuracy for all types of PJI (76.9%). 4.25% of AL cases had implant failure due to implant-related infection during the first year after the index revision arthroplasty, only the cases with early failure maintained high D-dimer levels.

CONCLUSIONS

Plasma D-dimer did not offer an improvement over the individual or combined diagnosis for any type of PJI according to IDSA criteria. Persistently raised levels of D-dimer after revision arthroplasty in AL cases might be used to effectively diagnose early postoperative infection.

Clinical experience of cefiderocol

Infections by antibiotic-resistant microorganisms could be considered a "stealth pandemic" that we fight daily in most hospitals. Some estimates suggest that today 700,000 deaths per year can be attributed to antimicrobial resistance. By the year 2050, it is estimated that this will increase to ten million deaths per year as a result of infections by multidrug-resistant microorganisms. In this context, the availability of antimicrobial therapy that is effective against these pathogens is essential to be able to "save the lives" of our patients. Cefiderocol, a new cephalosporin with a different mechanism of action, will be an essential treatment in many infections caused by resistant aerobic gram-negative bacteria. Cefiderocol has been used to treat patients with complicated urinary tract infections (cUTI); hospital-acquired pneumonia (HAP), ventilator-associated pneumonia (VAP), healthcare-associated pneumonia (HAP); in patients with sepsis and bacteremia, some without an identified primary focus of infection.

Prevention, Diagnosis and Management of Post-Surgical Mediastinitis in Adults Consensus Guidelines of the Spanish Society of Cardiovascular Infections (SEICAV), the Spanish Society of Thoracic and Cardiovascular Surgery (SECTCV) and the Biomedical Research Centre Network for Respiratory Diseases (CIBERES)

This is a consensus document of the Spanish Society of Cardiovascular Infections (SEICAV), the Spanish Society of Thoracic and Cardiovascular Surgery (SECTCV) and the Biomedical Research Centre Network for Respiratory Diseases (CIBERES). These three entities have brought together a multidisciplinary group of experts that includes anaesthesiologists, cardiac and cardiothoracic surgeons, clinical microbiologists, infectious diseases and intensive care specialists, internal medicine doctors and radiologists. Despite the clinical and economic consequences of sternal wound infections, to date, there are no specific guidelines for the prevention, diagnosis and management of mediastinitis based on a multidisciplinary consensus. The purpose of the present document is to provide evidence-based guidance on the most effective diagnosis and management of patients who have experienced or are at risk of developing a post-surgical mediastinitis infection in order to optimise patient outcomes and the process of care. The intended users of the document are health care providers who help patients make decisions regarding their treatment, aiming to optimise the benefits and minimise any harm as well as the workload.

Clinical management of cUTI, cIAI, and HABP/VABP attributable to carbapenem-resistant Gram-negative infections in Spain

Introduction. Carbapenem-resistant Gram-negative (CRGN) infections are a major public health problem in Spain, often implicated in complicated, healthcare-associated infections that require the use of potentially toxic antibacterial agents of last resort. The objective of this study was to assess the clinical management of complicated infections caused by CRGN bacteria in Spanish hospitals. Methods. The study included: 1) a survey assessing the GN infection and antibacterial susceptibility profile in five participating Spanish hospitals and 2) a non-interventional, retrospective single cohort chart review of 100 patients with complicated urinary tract infection (cUTI), complicated intra-abdominal infection (cIAI), or hospital-acquired bacterial pneumonia/ventilator-associated bacterial pneumonia (HABP/VABP) attributable to CRGN pathogens. Results. In the participating hospitals CRGN prevalence was 9.3% amongst complicated infections. In the retrospective cohort, 92% of infections were healthcare-associated, and Klebsiella pneumoniae and Pseudomonas aeruginosa were the most common pathogens. OXA was the most frequently detected carbapenemase type (71.4%). We found that carbapenems were frequently used to treat cUTI, cIAI, HABP/VABP caused by CRGN pathogens. Carbapenem use, particularly in combination with other agents, persisted after confirmation of carbapenem resistance. Clinical cure was 66.0%, mortality during hospitalization 35.0%, mortality at the time of chart review 62.0%, and 6-months-post-discharge readmission 47.7%. Conclusion. Our results reflect the high burden and unmet needs associated with the management of complicated infections attributable to CRGN pathogens in Spain and highlight the urgent need for enhanced clinical management of these difficult-to-treat infections.

Propensity Score and Desirability of Outcome Ranking Analysis of Ertapenem for Treatment of Nonsevere Bacteremic Urinary Tract Infections Due to Extended-Spectrum-Beta-Lactamase-Producing Enterobacterales in Kidney Transplant Recipients

There are scarce data on the efficacy of ertapenem in the treatment of bacteremia due to extended-spectrum-beta-lactamase (ESBL)-producing Enterobacterales (ESBL-E) in kidney transplant (KT) recipients. We evaluated the association between treatment with ertapenem or meropenem and clinical cure in KT recipients with nonsevere bacteremic urinary tract infections (B-UTI) caused by ESBL-E. We performed a registered, retrospective, international (29 centers in 14 countries) cohort study (INCREMENT-SOT, NCT02852902). The association between targeted therapy with ertapenem versus meropenem and clinical cure at day 14 (the principal outcome) was studied by logistic regression. Propensity score matching and desirability of outcome ranking (DOOR) analyses were also performed. A total of 201 patients were included; only 1 patient (treated with meropenem) in the cohort died. Clinical cure at day 14 was reached in 45/100 (45%) and 51/101 (50.5%) of patients treated with ertapenem and meropenem, respectively (adjusted OR 1.29; 95% CI 0.51 to 3.22; P = 0.76); the propensity score-matched cohort included 55 pairs (adjusted OR for clinical cure at day 14, 1.18; 95% CI 0.43 to 3.29; P = 0.74). In this cohort, the proportion of cases treated with ertapenem with better DOOR than with meropenem was 49.7% (95% CI, 40.4 to 59.1%) when hospital stay was considered. It ranged from 59 to 67% in different scenarios of a modified (weights-based) DOOR sensitivity analysis when potential ecological advantage or cost was considered in addition to outcome. In conclusion, targeted therapy with ertapenem appears as effective as meropenem to treat nonsevere B-UTI due to ESBL-E in KT recipients and may have some advantages.

Evaluation of endothelial function and subclinical atherosclerosis in patients with HIV infection

The aim of this study was to analyse the association between human immunodeficiency virus (HIV) related clinical and analytical parameters and the presence of subclinical atherosclerosis as well as endothelial dysfunction. This was a prospective cohort study of HIV-positive patients who underwent intima media thickness (IMT) determination and coronary artery calcium scoring to determine subclinical atherosclerosis. To detect endothelial dysfunction, the breath holding index, flow-mediated dilation and the concentration of endothelial progenitor cells (EPCs) were measured. Patients with an IMT ≥ 0.9 mm had an average of 559.3 ± 283.34 CD4/μl, and those with an IMT < 0.9 mm had an average of 715.4 ± 389.92 CD4/μl (p = 0.04). Patients with a low calcium score had a significantly higher average CD4 cell value and lower zenith viral load (VL) than those with a higher score (707.7 ± 377.5 CD4/μl vs 477.23 ± 235.7 CD4/μl (p = 0.01) and 7 × 10⁴ ± 5 × 10⁴ copies/ml vs 23.4 × 104 ± 19 × 104 copies/ml (p = 0.02)). The number of early EPCs in patients with a CD4 nadir < 350/µl was lower than that in those with a CD4 nadir ≥ 350 (p = 0.03). In HIV-positive patients, low CD4 cell levels and high VL were associated with risk of developing subclinical atherosclerosis. HIV patients with CD4 cell nadir < 350/µl may have fewer early EPCs.

Innate and Adaptive Immune Assessment at Admission to Predict Clinical Outcome in COVID-19 Patients

During the COVID-19 pandemic, many studies have been carried out to evaluate different immune system components to search for prognostic biomarkers of the disease. A broad multiparametric antibody panel of cellular and humoral components of the innate and the adaptative immune response in patients with active SARS-CoV-2 infection has been evaluated in this study. A total of 155 patients were studied at admission into our center and were categorized according to the requirement of oxygen therapy as mild or severe (the latter being those with the requirement). The patients with severe disease were older and had high ferritin, D-dimer, C-reactive protein, troponin, interleukin-6 (IL-6) levels, and neutrophilia with lymphopenia at admission. Moreover, the patients with mild symptoms had significantly increased circulating non-classical monocytes, innate lymphoid cells, and regulatory NK cells. In contrast, severe patients had a low frequency of Th1 and regulatory T cells with increased activated and exhausted CD8 phenotype (CD8⁺CD38⁺HLADR⁺ and CD8⁺CD27^-CD28^-, respectively). The predictive model included age, ferritin, D-dimer, lymph counts, C4, CD8⁺CD27^-CD28^-, and non-classical monocytes in the logistic regression analysis. The model predicted severity with an area under the curve of 78%. Both innate and adaptive immune parameters could be considered potential predictive biomarkers of the prognosis of COVID-19 disease.

Analysis of sex differences in the clinical presentation, management and prognosis of infective endocarditis in Spain

INTRODUCTION

Sex-dependent differences of infective endocarditis (IE) have been reported. Women suffer from IE less frequently than men and tend to present more severe manifestations. Our objective was to analyse the sex-based differences of IE in the clinical presentation, treatment, and prognosis.

MATERIAL AND METHODS

We analysed the sex differences in the clinical presentation, modality of treatment and prognosis of IE in a national-level multicentric cohort between 2008 and 2018. All data were prospectively recorded by the GAMES cohort (Spanish Collaboration on Endocarditis).

RESULTS

A total of 3451 patients were included, of whom 1105 were women (32.0%). Women were older than men (mean age, 68.4 vs 64.5). The most frequently affected valves were the aortic valve in men (50.6%) and mitral valve in women (48.7%). Staphylococcus aureus aetiology was more frequent in women (30.1% vs 23.1%; p<0.001).Surgery was performed in 38.3% of women and 50% of men. After propensity score (PS) matching for age and estimated surgical risk (European System for Cardiac Operative Risk Evaluation II (EuroSCORE II)), the analysis of the matched cohorts revealed that women were less likely to undergo surgery (OR 0.74; 95% CI 0.59 to 0.91; p=0.05).The observed overall in-hospital mortality was 32.8% in women and 25.7% in men (OR for the mortality of female sex 1.41; 95% CI 1.21 to 1.65; p<0.001). This statistical difference was not modified after adjusting for all possible confounders.

CONCLUSIONS

Female sex was an independent factor related to mortality after adjusting for confounders. In addition, women were less frequently referred for surgical treatment.