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P. aeruginosa bacteremia is a common and severe infection carrying high mortality in older adults. We aimed to evaluate outcomes of P. aeruginosa bacteremia among old adults (≥ 80 years).We included the 464/2394 (19%) older adults from a retrospective multinational (9 countries, 25 centers) cohort study of individuals hospitalized with P. aeruginosa bacteremia. Bivariate and multivariable logistic regression models were used to evaluate risk factors for 30-day mortality among older adults.Among 464 adults aged ≥ 80 years, the mean age was 84.61 (SD 3.98) years, and 274 (59%) were men. Compared to younger patients, ≥ 80 years adults had lower Charlson score; were less likely to have nosocomial acquisition; and more likely to have urinary source. Thirty-day mortality was 30%, versus 27% among patients 65-79 years (n = 894) and 25% among patients 65 years (n = 1036). Multivariate analysis for predictors of mortality among patients ≥ 80 years, demonstrated higher SOFA score (odds ratio [OR] 1.36, 95% confidence interval [CI] 1.23-1.51, p 0.001), corticosteroid therapy (OR 3.15, 95% CI: 1.24-8.01, p = 0.016) and hospital acquired P. aeruginosa bacteremia (OR 2.30, 95% CI: 1.33-3.98, p = 0.003) as predictors. Appropriate empirical therapy within 24 h, type of definitive anti-pseudomonal drug, and type of regimen (monotherapy or combination) were not associated with 30-day mortality.In older adults with P. aeruginosa bacteremia, background conditions, place of acquisition, and disease severity are associated with mortality, rather than the antimicrobial regimen. In this regard, preventive efforts and early diagnosis before organ failure develops might be beneficial for improving outcomes.

Bacterial antibiotic resistance is a serious global public health concern. Infections caused by colistin-resistant Pseudomonas aeruginosa (CRPa) strains represent a serious threat due to their considerable morbidity and mortality rates, since most of the current empirical antibiotic therapies are ineffective against these strains. Accordingly, cationic antimicrobial peptides (CAMPs) have emerged as promising alternatives to control resistant bacteria. In this study, the interaction of a CAMP derived from cecropin D-like (∆M2) with model membranes mimicking bacterial biomembranes of wild-type (WTPa) strains of P. aeruginosa and CRPa was evaluated through in vitro and in silico approaches. In vitro interaction was determined by infrared spectroscopy, whereas in silico molecular dynamics was performed to predict specific interactions between amino acids of ∆M2 and lipids of model membrane systems. Experimental analysis showed this peptide interacted with the lipids of bacterial-like model membranes of WTPa and CRPa. In both cases, an increase in the concentration of peptides induced an increase in the phase transition temperature of the lipid systems. On the other hand, the peptides in solution underwent a transition from a random to a helical secondary structure after interacting with the membranes mostly favored in the CRPa system. The α-helix structure percentage for ΔM2 interacting with WTPa and CRPa lipid systems was 6.4 and 33.2%, respectively. Finally, molecular dynamics showed ∆M2 to have the most affinities toward the phospholipids palmitoyl-oleyl-phosphatidylglycerol (POPG) and palmitoyl-oleoyl-phosphatidylethanolamine (POPE) that mimic membranes of WTPa and CRPa, respectively. This work provides clues for elucidating the membrane-associated mechanism of action of ∆M2 against colistin-susceptible and -resistant strains of Pseudomonas aeruginosa.

Objectives To detect a potential hidden dissemination of the blaOXA-48 gene among Proteus mirabilis isolates obtained from a single centre. Methods P. mirabilis from diverse clinical samples presenting an ESBL phenotype or obtained from blood cultured from 2017 to 2019 were evaluated. Bacterial identification was performed using MALDI-TOF MS. MICs were determined using International Organization for Standardization (ISO) standard microdilution and interpreted following EUCAST guidelines. WGS was performed using both short- and long-read technologies and assemblies were done using Unicycler. Resistomes were assessed using the ResFinder database. SNPs were detected using the PATRIC bioinformatics platform. Cloning experiments were performed using the pCRII-TOPO cloning kit. Results Thirty-one out of 108 (28.7%) isolates were positive for blaOXA-48 and blaCTX-M-15. Twenty-nine out of 31 of the isolates were susceptible to temocillin, piperacillin/tazobactam, ertapenem and meropenem, whereas only 2/31 showed a resistance phenotype against these antibiotics. Both blaOXA-48 and blaCTX-M-15 genes were detected within the same chromosomally integrated new transposon in all isolates. The resistant isolates displayed a single mutation located in the putative promoter upstream of blaOXA-48. Cloning experiments confirmed that the mutation was responsible for the resistance phenotype. Conclusions The presence of a chromosomal copy of blaOXA-48 did not confer resistance to carbapenems, but a single mutation in the promoter could lead to an increase in resistance. This study shows a hidden circulation of OXA-48-positive, but carbapenem- and piperacillin/tazobactam-susceptible, P. mirabilis isolates that can become resistant to β-lactams after a single mutation.

Bacterial antibiotic resistance is a serious global public health concern. Infections caused by colistin-resistant

Background The aim of this study was to evaluate three commercially available methods (Allplex SARS-CoV-2 Assay, Allplex SARS-CoV-2/FluA/FluB/RSV Assay and Novaplex SARS-CoV-2 Variants I Assay) for screening of the SARS-CoV-2 VOC 202012/01 B.1.1.7 variant. Methods A total of 160 nasopharyngeal samples (150 positive and 10 negative for SARS-CoV-2) were tested with all three molecular assays. Next-generation sequencing (NGS) was used as the reference method to determine analytical performance. Results Total (100%) agreement was found for SARS-CoV-2 detection with all three assays. For B.1.1.7 screening, the sensitivity of the Allplex SARS-CoV-2 Assay, the Allplex SARS-CoV-2/FluA/FluB/RSV Assay and the Novaplex SARS-CoV-2 Variants I Assay (Seegene Inc.) were 94.5%, 98.7% and 100 %, respectively, while the specificities of the assays were 98.6%, 81.7% and 100%, respectively. Conclusions Although the best results for identifying the B.1.1.7 variant in this study were achieved with the Novaplex Variants I Assay, the three approaches evaluated can be considered cost-effective primary screening tools to rapidly monitor the VOC 202012/01 B.1.1.7 variant.

Today, welding tasks can be accomplished in two ways: 1) Manual or conventional, which is made by humans with a welding gun; and 2) Automated welding that is carried out by robots, this robots are called “Welding Robots”. Current welding robots are able to perform welding tasks continuously under different working conditions in low-scale production such as shipbuilding or in high-scale production such as in the automotive industry. Even in well defined and structured environments such as in the automotive industry robot reprogramming is still necessary in order to cope with uncertainties. This additional task involves hiring specialized personnel, lost of production time, quality assessment, destructive testing, etc., which necessarily increases the production costs. The design proposal considers first to simulate the whole welding process considering issues like floor plant space, robot configuration, trajectory planning, welding equipment and supplies, etc. and secondly, the utilization of novel teaching tools for welding trajectories. The contribution has been divided in two chapters as follows: In Part I, the robotic cell set up (including off-line and on-line programming) using current 3D software simulation, equipment commissioning and testing, distributed workcell communication and the voice-command program design are presented; while in Part II, the description of an error recovery strategy in conjunction with a novel teaching trajectory using machine vision is presented. In this chapter, we describe the design to integrate a robotic welding cell within a 3D simulation environment. The design was used as a reference for the actual construction of the robotized GMAW welding cell. We report a methodology to set up a welding robot cell from scratch using a 3D software robot simulation from Delmia named Robotics V5®. The simulation included welding accessories that were designed first in CAD software and imported by the Delmia® software. These accessories were gas tanks, wire coils, Lincoln 455 25

[Background] Pseudomonas aeruginosa bacteraemia is a common and serious infection. No consensus exists regarding whether definitive combination therapy is superior to monotherapy. We aimed to evaluate the impact of combination therapy on mortality., [Methods] This was a multicentre retrospective study (nine countries, 25 centres), including 1277 patients with P. aeruginosa bacteraemia during 2009–15. We evaluated the association between β-lactam plus aminoglycoside or quinolone combination therapy versus β-lactam monotherapy and mortality. The primary outcome was 30 day all-cause mortality. Univariate and multivariate Cox regression analyses were conducted, introducing combination as a time-dependent variable. Propensity score was conducted to adjust for confounding for choosing combination therapy over monotherapy., [Results] Of 1119 patients included, 843 received definitive monotherapy and 276 received combination therapy (59% aminoglycoside and 41% quinolone). Mortality at 30 days was 16.9% (189/1119) and was similar between combination (45/276; 16.3%) and monotherapy (144/843; 17.1%) groups (P = 0.765). In multivariate Cox regression, combination therapy was not associated with reduced mortality (HR 0.98, 95% CI 0.64–1.53). No advantage in terms of clinical failure, microbiological failure or recurrent/persistent bacteraemia was demonstrated using combination therapy. Likewise, adverse events and resistance development were similar for the two regimens., [Conclusions] In this retrospective cohort, no mortality advantage was demonstrated using combination therapy over monotherapy for P. aeruginosa bacteraemia. Combination therapy did not improve clinical or microbiological failure rates, nor affect adverse events or resistance development. Our finding of no benefit with combination therapy needs confirmation in well-designed randomized controlled trials.

This study was presented as poster presentation at the European Society of Clinical Microbiology and Infectious Diseases annual conference, Madrid, Spain, 21–24 April 2018., [Background] The optimal antibiotic regimen for Pseudomonas aeruginosa bacteremia is controversial. Although β-lactam monotherapy is common, data to guide the choice between antibiotics are scarce. We aimed to compare ceftazidime, carbapenems, and piperacillin-tazobactam as definitive monotherapy. [Methods] A multinational retrospective study (9 countries, 25 centers) including 767 hospitalized patients with P. aeruginosa bacteremia treated with β-lactam monotherapy during 2009–2015. The primary outcome was 30-day all-cause mortality. Univariate and multivariate, including propensity-adjusted, analyses were conducted introducing monotherapy type as an independent variable. [Results] Thirty-day mortality was 37/213 (17.4%), 42/210 (20%), and 55/344 (16%) in the ceftazidime, carbapenem, and piperacillin-tazobactam groups, respectively. Type of monotherapy was not significantly associated with mortality in either univariate, multivariate, or propensity-adjusted analyses (odds ratio [OR], 1.14; 95% confidence interval [CI], 0.52–2.46, for ceftazidime; OR, 1.3; 95% CI, 0.67–2.51, for piperacillin-tazobactam, with carbapenems as reference in propensity adjusted multivariate analysis; 542 patients). No significant difference between antibiotics was demonstrated for clinical failure, microbiological failure, or adverse events. Isolation of P. aeruginosa with new resistance to antipseudomonal drugs was significantly more frequent with carbapenems (36/206 [17.5%]) versus ceftazidime (25/201 [12.4%]) and piperacillin-tazobactam (28/332 [8.4%] (P = .007). [Conclusions] No significant difference in mortality, clinical, and microbiological outcomes or adverse events was demonstrated between ceftazidime, carbapenems, and piperacillin-tazobactam as definitive treatment of P. aeruginosa bacteremia. Higher rates of resistant P. aeruginosa after patients were treated with carbapenems, along with the general preference for carbapenem-sparing regimens, suggests using ceftazidime or piperacillin-tazobactam for treating susceptible infection., This study was conducted with no external funding. In Sweden only, the research was funded by grants from the Stockholm County Council and Emil and Wera Cornell Foundation.

Phage therapy is an abandoned antimicrobial therapy that has been resumed in recent years. In this study, we mutated a lysogenic phage from Acinetobacter baumannii into a lytic phage (Ab105-2phiΔCI) that displayed antimicrobial activity against A. baumannii clinical strain Ab177_GEIH-2000 (isolated in the GEIH-REIPI Spanish Multicenter A. baumannii Study II 2000/2010, Umbrella Genbank Bioproject PRJNA422585, and for which meropenem and imipenem MICs of respectively, 32 µg/mL, and 16 µg/mL were obtained). We observed an in vitro synergistic antimicrobial effect (reduction of 4 log–7 log CFU/mL) between meropenem and the lytic phage in all combinations analyzed (Ab105-2phiΔCI mutant at 0.1, 1 and 10 MOI and meropenem at 1/4 and 1/8 MIC). Moreover, bacterial growth was reduced by 8 log CFU/mL for the combination of imipenem at 1/4 MIC plus lytic phage (Ab105-2phiΔCI mutant) and by 4 log CFU/mL for the combination of imipenem at 1/8 MIC plus lytic phage (Ab105-2phiΔCI mutant) at both MOI 1 and 10. These results were confirmed in an in vivo model (G. mellonella), and the combination of imipenem and mutant Ab105-2phiΔCI was most effective (p < 0.05). This approach could help to reduce the emergence of phage resistant bacteria and restore sensitivity to antibiotics used to combat multi-resistant strains of Acinetobacter baumannii.

In Klebsiella pneumoniae, loss of the two major outer membrane porins (OMPs) OmpK35 and OmpK36 confers resistance to carbapenems in strains producing extended-spectrum β-lactamases (ESBLs) or plasmid-mediated AmpC-type β-lactamases. This study investigated mechanisms responsible for carbapenem resistance in non-carbapenemase-producing K. pneumoniae (NCPK). All carbapenem-resistant Enterobacteriaceae (CRE) at Charles Nicolle Hospital (Tunis, Tunisia) were collected over a 6-year period (2010-2015). Among the 334 CRE strains collected, 44 (13.2%) were NCPK. MIC ranges for ertapenem, imipenem and meropenem were 1 to32 mg/L, 0.125-8 mg/L and 0.125-32 mg/L, respectively. All strains showed a multidrug-resistant (MDR) phenotype and were negative for carbapenemase activity. None of the carbapenemase genes searched for were found. ESBL production was confirmed in all isolates except one [CTX-M-15 (n = 39) and SHV-5 (n = 4)]. Three isolates produce DHA-1 (associated with CTX-M-15 in two strains). Molecular fingerprints grouped the 44 NCPK isolates into seven clusters. In seven representative strains of these clusters, SDS-PAGE results showed that four isolates lacked the OmpK35 porin, one isolate lacked OmpK36 and two isolates lacked both OmpK35 and OmpK36. Sequencing of the corresponding porin genes showed amino acid insertions and deletions leading to early termination of translation, point mutations in the promoter region, or insertion sequences disrupting the gene coding sequence. Loss or deficiency of OMPs, coupled with ESBL and/or AmpC production, plays an important role in conferring carbapenem resistance in K. pneumoniae. Dissemination of these MDR bacteria in our hospital may create serious therapeutic problems in the future.

Two regions of northern Spain, Gipuzkoa, and Cantabria present high annual incidence of listeriosis (1.86 and 1.71 cases per 100,000 inhabitants, respectively). We report that the high annual incidences are a consequence of infection with highly virulent Listeria monocytogenes isolates linked to fatal outcomes in elderly patients with cancer. In addition, listeriosis patients with cancer present low IL-17A/IL-6 ratios and significantly reduced levels of anti-GAPDH1?22 antibodies, identified as two novel biomarkers of poor prognosis. Analysis of these biomarkers may aid in reducing the incidence of listeriosis. Moreover, GAPDH1?22-activated monocyte-derived dendritic cells of listeriosis patients with cancer seem useful tools to prepare clinical vaccines as they produce mainly Th1 cytokines.

Resume La medecine moderne a conduit a un besoin continuellement croissant de catheters intravasculaires pour nutrition parenterale, administration de medicaments et surveillance cardiovasculaire. C'est ainsi que le nombre de patients exposes a un risque accru d'infections liees aux catheters augmente de facon reguliere. Ces constatations ont nourri l'interet porte a la physiopathologie, au traitement et a la prevention des infections liees aux catheters, ainsi qu'a l'epidemiologie bacterienne et aux facteurs de virulence des principaux agents infectieux responsables, surtout Staphylococcus epidermidis et autres staphylocoques a coagulase negative. La presente mise au point passe en revue un certain nombre de ces aspects des infections liees aux catheters. Nous avons en particulier evalue le role des antibiotiques sur l'adherence de S. epidermidis aux biomateriaux en incluant les donnees tirees de nos propres experimentations. Nous avons demontre que le pre-traitement de souches de S. epidermidis par des concentrations subinhibitrices de rifampicine, de vancomycine et de cloxacilline entraine une diminution significative de l'adherence de ces souches. A l'aide du SDS-PAGE des proteines de surface staphylococciques, nous avons obtenu la preuve de l'implication d'un polypeptide de 220 kDa dans l'adherence bacterienne. En outre, les etudes en microscopie electronique de la surface des staphylocoques ont revele la presence de structures « fimbriae-like a la surface de diverses souches de S. epidermidis . Le role precis de la « proteine d'adherence de 220 kDa et de filaments « fimbriae-like dans l'adherence des staphylocoques a coagulase negative aux biomateriaux est discute.