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BackgroundTherapeutic drug monitoring (TDM) of β-lactams in critically ill patients has been correlated with better clinical outcomes. Evidence on TDM of newer β-lactams such as ceftazidime/avibactam administered by continuous infusion (CI) is very limited.ObjectivesTo describe our experience with TDM of ceftazidime/avibactam and pharmacokinetic/pharmacodynamic (PK/PD) target attainment in patients with MDR bacterial infections. Clinical outcomes of ceftazidime/avibactam administered by CI were also assessed.MethodsPatients treated with ceftazidime/avibactam administered by CI and undergoing TDM of ceftazidime plasma concentrations were included. Blood samples were obtained as part of the TDM program. The PK/PD therapeutic target of ceftazidime/avibactam was defined as 100%fT > 4 × MIC of the causative pathogen, and 100%fT > 10 × MIC was considered overexposure. Dose changes were made according to the TDM results.ResultsThirty-one patients were included. Ceftazidime/avibactam total daily doses ranged from 1 g/0.25 g to 6 g/1.5 g. Twenty-six patients (83.9%) achieved a 100%fT > 4 × MIC, 15 (48.4%) of which were overexposed (100%fT > 10 × MIC). Dose reduction was suggested in 16/28 (57.1%) patients and dose maintenance in 12/28 (42.9%). Overall clinical cure was observed in 21 (67.7%) patients, and 18 of these (85.7%) achieved a 100%fT > 4 × MIC.ConclusionsAdministering ceftazidime/avibactam by CI enabled the desired PK/PD target to be achieved in a large proportion of patients, even at lower doses than those recommended for a 2 h extended infusion. We suggest that the use of CI with TDM may be a useful tool for reducing initial doses, which could help to reduce antimicrobial-related adverse effects and treatment costs.

Rationale: Tools for the evaluation of COVID-19 severity would help clinicians with triage decisions, especially the decision whether to admit to ICU. Objective: Evaluation of SeptiCyte RAPID, a host immune response assay (Immunexpress, Seattle USA) as a triaging tool for COVID-19 patients requiring hospitalization and potentially ICU care. Methods: SeptiCyte RAPID employs a host gene expression signature consisting of the ratio of expression levels of two immune related mRNAs, PLA2G7 and PLAC8, measured from whole blood samples. Blood samples from 146 adult SARS-CoV-2 (+) patients were collected within 48 hours of hospital admission in PAXgene blood RNA tubes at Hospital del Mar, Barcelona, Spain, between July 28th - December 1st, 2020. Data on demographics, vital signs, clinical chemistry parameters, radiology, interventions, and SeptiCyte RAPID were collected and analyzed with bioinformatics methods. The performance of SeptiCyte RAPID for COVID-19 severity assessment and ICU admission was evaluated, relative to the comparator of retrospective clinical assessment by the Hospital del Mar clinical care team. Measurements and Main Results: SeptiCyte RAPID was able to stratify COVID-19 cases according to clinical severity: critical vs. mild (AUC=0.92, p

The aim of this study was to compare the efficacy of intermittent (1-h), extended (4-h), and continuous ceftolozane-tazobactam (C/T) infusion against three extensively drug-resistant (XDR) sequence type (ST) 175 P. aeruginosa isolates with different susceptibilities to C/T (MIC = 2 to 16 mg/L) in a 7-day hollow-fiber infection model (HFIM). C/T in continuous infusion achieved the largest reduction in total number of bacterial colonies in the overall treatment arms for both C/T-susceptible and -resistant isolates. It was also the only regimen with bactericidal activity against all three isolates. These data suggest that continuous C/T infusion should be considered a potential treatment for infections caused by XDR P. aeruginosa isolates, including nonsusceptible ones. Proper use of C/T dosing regimens may lead to better clinical management of XDR P. aeruginosa infections. IMPORTANCE Ceftolozane-tazobactam (C/T) is an antipseudomonal antibiotic with a high clinical impact in treating infection caused by extensively drug-resistant (XDR) Pseudomonas aeruginosa isolates, but resistance is emerging. Given its time-dependent behavior, C/T continuous infusion can improve exposure and therefore the pharmacokinetic/pharmacodynamic target attainment. We compared the efficacy of intermittent, extended, and continuous C/T infusion against three XDR ST175 P. aeruginosa isolates with different C/T MICs by means of an in vitro dynamic hollow-fiber model. We demonstrated that C/T in continuous infusion achieved the largest reduction in bacterial density in the overall treatment arms for both susceptible and resistant isolates. It was also the only regimen with bactericidal activity against all three isolates. Through this study, we want to demonstrate that developing individually tailored antimicrobial treatments is becoming essential. Our results support the role of C/T level monitoring and of dose adjustments for better clinical management and outcomes.

Introduction: Chronic kidney disease (CKD) increases the risk of mortality during coronavirus disease 2019 (COVID-19) episodes, and some reports have underlined the high incidence and severity of this infection in dialysis patients. Information on COVID-19 in nondialysis CKD patients is not available yet. Case Reports: Here we present 7 patients with grade 4–5 CKD who developed symptomatic COVID-19; they comprise 2.6% of our 267 advanced CKD patients. The estimated GFR was between 12 and 20 mL/min during the month prior to COVID-19. The 3 major symptoms were fever, cough, and dyspnea, and 5 patients showed bilateral pneumonia. Hydroxychloroquine, azithromycin, ceftriaxone, and steroids were the most frequently prescribed drugs. Two patients needed noninvasive mechanical ventilation. All patients showed minimal to moderate kidney function deterioration during admission, with an eGFR decline below 5 mL/min in 6 cases. No patient required acute dialysis. Six patients were discharged alive and remained dialysis free athe t the time of reporting, and one 76-year-old patient died. Conclusions: COVID-19 affects grade 4–5 CKD patients, but prognosis may be acceptable if prompt supportive measures are applied. These findings should be confirmed in larger cohorts, and further observations will be needed to understand the full spectrum of clinical features and the optimal approach to COVID-19 in patients with advanced CKD.

Time-kill curves are used to study antibiotic combinations, but the colony count method to obtain the results is time-consuming. The aim of the study was to validate an ATP assay as an alternative to the conventional colony count method in studies of antibiotic combinations. The cutoff point for synergy and bactericidal effect to categorize the results using this alternative method were determined in Pseudomonas aeruginosa. The ATP assay was performed using the GloMax 96 microplate luminometer (Promega), which measures bioluminescence in relative light units (RLU). To standardize this assay, background, linearity, and the detection limit were determined with one strain each of multidrug-resistant P. aeruginosa and Klebsiella pneumoniae. Twenty-four-hour time-kill curves were performed in parallel by both methods with 12 strains of P. aeruginosa. The conventional method was used as a "gold" standard to establish the pharmacodynamic cutoff points in the ATP method. Normal saline solution was established as washing/dilution medium. RLU signal correlated with CFU when the assay was performed within the linear range. The categorization of the pharmacodynamic parameters using the ATP assay was equivalent to that of the colony count method. The bactericidal effect and synergy cutoff points were 1.348 (93% sensitivity, 81% specificity) and 1.065 (95% sensitivity, 89% specificity) log RLU/mL, respectively. The ATP assay was useful to determine the effectiveness of antibiotic combinations in time-kill curves. This method, less laborious and faster than the colony count method, could be implemented in the clinical laboratory workflow. IMPORTANCE Combining antibiotics is one of the few strategies available to overcome infections caused by multidrug-resistant bacteria. Time-kill curves are usually performed to evaluate antibiotic combinations, but obtaining results is too laborious to be routinely performed in a clinical laboratory. Our results support the utility of an ATP measurement assay using bioluminescence to determine the effectiveness of antibiotic combinations in time-kill curves. This method may be implemented in the clinical laboratory workflow as it is less laborious and faster than the conventional colony count method. Shortening the obtention of results to 24 h would also allow an earlier guided combined antibiotic treatment.

Data de publicació electrònica: 20-04-2022 Background: To compare clinical characteristics, outcomes, and resource consumption of patients with COVID-19 and seasonal influenza requiring supplemental oxygen. Methods: Retrospective cohort study conducted at a tertiary-care hospital. Patients admitted due to seasonal influenza between 2017 and 2019, or with COVID-19 between March and May 2020 requiring supplemental oxygen were compared. Primary outcome: 30-day mortality. Secondary outcomes: 90-day mortality and hospitalization costs. Attempted sample size to detect an 11% difference in mortality was 187 patients per group. Results: COVID-19 cases were younger (median years, 67 (IQR 54-78) vs 76 (IQR 64-83); p < 0.001) and more frequently overweight whereas influenza cases had more hypertension, immunosuppression, and chronic heart, respiratory and renal disease. Compared to influenza, COVID-19 cases had more pneumonia (98% vs 60%

Background To compare clinical characteristics, outcomes, and resource consumption of patients with coronavirus disease 2019 (COVID-19) and seasonal influenza requiring supplemental oxygen. Methods Retrospective cohort study conducted at a tertiary-care hospital. Patients admitted because of seasonal influenza between 2017 and 2019, or with COVID-19 between March and May 2020 requiring supplemental oxygen were compared. Primary outcome: 30-day mortality. Secondary outcomes: 90-day mortality and hospitalization costs. Attempted sample size to detect an 11% difference in mortality was 187 patients per group. Results COVID-19 cases were younger (median years of age, 67; interquartile range [IQR] 54–78 vs 76 [IQR 64–83]; P < .001) and more frequently overweight, whereas influenza cases had more hypertension, immunosuppression, and chronic heart, respiratory, and renal disease. Compared with influenza, COVID-19 cases had more pneumonia (98% vs 60%, 65 years) scores and were more likely to show worse progression on the World Health Organization ordinal scale (33% vs 4%; P < .001). The 30-day mortality rate was higher for COVID-19 than for influenza: 15% vs 5% (P = .001). The median age of nonsurviving cases was 81 (IQR 74–88) and 77.5 (IQR 65–84) (P = .385), respectively. COVID-19 was independently associated with 30-day (hazard ratio [HR], 4.6; 95% confidence interval [CI], 2–10.4) and 90-day (HR, 5.2; 95% CI, 2.4–11.4) mortality. Sensitivity and subgroup analyses, including a subgroup considering only patients with pneumonia, did not show different trends. Regarding resource consumption, COVID-19 patients had longer hospital stays and higher critical care, pharmacy, and complementary test costs. Conclusions Although influenza patients were older and had more comorbidities, COVID-19 cases requiring supplemental oxygen on admission had worse clinical and economic outcomes.

Ceftolozane/tazobactam (C/T) has emerged as a potential agent for the treatment of extensively drug-resistant (XDR) Pseudomonas aeruginosa infections. As it is a time-dependent antimicrobial, prolonged infusion may help achieve pharmacokinetic/pharmacodynamic (PK/PD) targets. To compare alternative steady-state concentrations (Css) of C/T in continuous infusion (CI) against three XDR P. aeruginosa ST175 isolates with C/T minimum inhibitory concentration (MIC) values of 2 to 16 mg/L in a hollow-fiber infection model (HFIM). Duplicate 10-day HFIM assays were performed to evaluate Css of C/T in CI: one compared 20 and 45 mg/L against the C/T-susceptible isolate while the other compared 45 and 80 mg/L against the two C/T-non-susceptible isolates. C/T resistance emerged when C/T-susceptible isolate was treated with C/T in CI at a Css of 20 mg/L; which showed a deletion in the gene encoding AmpC β-lactamase. The higher dosing regimen (80 mg/L) showed a slight advantage in effectiveness. The higher dosing regimen has the greatest bactericidal effect, regardless of C/T MIC. Exposure to the suboptimal Css of 20 mg/L led to the emergence of C/T resistance in the susceptible isolate. Antimicrobial regimens should be optimized through C/T levels monitoring and dose adjustments to improve clinical management.

Ceftolozane-tazobactam is currently the most active antipseudomonal agent, including multidrug-resistant extensively drug-resistant strains. Tazobactam provides additional activity against many extended-spectrum beta-lactamases Enterobacterales. Ceftolozane-tazobactam is formally approved for complicated urinary tract infection, complicated intra-abdominal infection, and hospital-acquired and ventilator-associated bacterial pneumonia. The clinical and microbiological success is over 70-80% in many series. However, resistant mutants to ceftolozane-tazobactam have been already described. Combination therapies with colistin or meropenem could be among the strategies to avoid the resistance emergence.

Ceftazidime-avibactam (CZA) has emerged as a promising solution to the lack of new antibiotics against Pseudomonas aeruginosa infections. Data from in vitro assays of CZA combinations, however, are scarce. The objective of our study was to perform a time-kill analysis of the effectiveness of CZA alone and in combination with other antibiotics against a collection of extensively drug-resistant (XDR) P. aeruginosa isolates. Twenty-one previously characterized representative XDR P. aeruginosa isolates were selected. Antibiotic susceptibility was tested by broth microdilution, and results were interpreted using CLSI criteria. The time-kill experiments were performed in duplicate for each isolate. Antibiotics were tested at clinically achievable free-drug concentrations. Different treatment options, including CZA alone and combined with amikacin, aztreonam, meropenem, and colistin, were evaluated to identify the most effective combinations. Seven isolates were resistant to CZA (MIC ≥ 16/4 mg/liter), including four metallo-β-lactamase (MBL)-carrying isolates and two class A carbapenemases. Five of them were resistant or intermediate to aztreonam (MIC ≥ 16 mg/liter). Three isolates were resistant to amikacin (MIC ≥ 64 mg/liter) and one to colistin (MIC ≥ 4 mg/liter). CZA monotherapy had a bactericidal effect in 100% (14/14) of the CZA-susceptible isolates. Combination therapies achieved a greater overall reduction in bacterial load than monotherapy for the CZA-resistant isolates. CZA plus colistin was additive or synergistic in 100% (7/7) of the CZA-resistant isolates, while CZA plus amikacin and CZA plus aztreonam were additive or synergistic in 85%. CZA combined with colistin, amikacin, or aztreonam was more effective than monotherapy against XDR P. aeruginosa isolates. A CZA combination could be useful for treating XDR P. aeruginosa infections, including those caused by CZA-resistant isolates. IMPORTANCE The emergence of resistance to antibiotics is a serious public health problem worldwide and can be a cause of mortality. For this reason, antibiotic treatment is compromised, and we have few therapeutic options to treat infections. The main goal of our study is to search for new treatment options for infections caused by difficult-to-treat resistant germs. Pseudomonas aeruginosa is a Gram-negative bacterium distributed throughout the world with the ability to become resistant to most available antibiotics. Ceftazidime-avibactam (CZA) emerged as a promising solution to the lack of new antibiotics against infections caused by P. aeruginosa strains. This study intended to analyze the effect of CZA alone or in combination with other available antibiotics against P. aeruginosa strains. The combination of CZA with other antibiotics could be more effective than monotherapy against extensively drug-resistant P. aeruginosa strains.

Objective: To analyze the clinical and economic impact of community-onset urinary tract infections (UTIs) caused by extended-spectrum beta-lactamase (ESBL)-producing Klebsiella pneumoniae requiring hospitalization. Methods: A retrospective cohort study that included all adults with a UTI caused by K. pneumoniae that were admitted to a tertiary care hospital in Barcelona, Spain, between 2011 and 2015. Demographic, clinical, and economic data were analyzed. Results: One hundred and seventy-three episodes of UTIs caused by K. pneumoniae were studied, 112 were non-ESBL-producing and 61 were ESBL-producing. Multivariate analysis identified ESBL production, acute confusional state associated with UTI, shock, and the time taken to obtain adequate treatment as risk factors for clinical failure during the first seven days. An economic analysis showed differences between ESBL-producing and non-ESBL-producing K. pneumoniae for the total cost of hospitalization per episode (mean EUR 6718 vs EUR 3688, respectively). Multivariate analysis of the higher costs of UTI episodes found statistically significant differences for ESBL production and the time taken to obtain adequate treatment. Conclusion: UTIs caused by ESBL-producing K. pneumoniae requiring hospitalization and the time taken to obtain adequate antimicrobial therapy are associated with worse clinical and economic outcomes.

Introduction: The aim of this study was to analyze a nosocomial coronavirus disease 2019 (COVID-19) outbreak that occurred on a polyvalent non-COVID-19 ward at a tertiary care university hospital in Spain during the first wave of the pandemic and to describe the containment measures taken. The outbreak affected healthcare workers (HCWs) and kidney disease patients including transplant patients and those requiring maintenance hemodialysis. Methods: The outbreak investigation and report were conducted in accordance with the Orion statement guidelines. Results: In this study, 15 cases of COVID-19 affecting 10 patients and 5 HCWs were identified on a ward with 31 beds and 43 HCWs. The patients had tested negative for severe acute respiratory syndrome coronavirus 2 infection on admission. One of the HCWs was identified as the probable index case. Five patients died (mortality rate, 50%). They were all elderly and had significant comorbidities. The infection control measures taken included the transfer of infected patients to COVID-19 isolation wards, implementation of universal preventive measures, weekly PCR testing of patients and HCWs linked to the ward, training of HCWs on infection control and prevention measures, and enhancement of cleaning and disinfection. The outbreak was contained in 2 weeks, and no new cases occurred. Conclusion: Nosocomial COVID-19 outbreaks can have high attack rates involving both patients and HCWs and carry a high risk of patient mortality. Hospitals need to implement effective infection prevention and control strategies to prevent nosocomial COVID-19 spread.

Objective: To analyze the clinical and economic impact of community-onset urinary tract infections (UTI) caused by extended-spectrum beta-lactamase (ESBL)-producing Klebsiella pneumoniae requiring hospitalization. Methods: A retrospective cohort study included all adults with UTI caused by K. pneumoniae admitted to a tertiary care hospital in Barcelona, Spain, between 2011 and 2015. Demographic, clinical and economic data were analyzed. Results: One hundred and seventy-three episodes of UTI caused by K. pneumoniae were studied; 112 were non-ESBL-producing and 61 ESBL-producing. Multivariate analysis identified ESBL production, acute confusional state associated with UTI, shock, and time to adequate treatment as risk factors for clinical failure during the first 7 days. Economic analysis showed differences between ESBL-producing and non-ESBL-producing K. pneumoniae for the total cost of hospitalization per episode (mean 6,718 € vs 3,688 € respectively). Multivariate analysis of the higher costs of UTI episodes found statistically significant differences for ESBL production and time to adequate treatment. Conclusion: UTI caused by ESBL-producing K. pneumoniae requiring hospitalization, and time to adequate antimicrobial therapy are associated with worse clinical and economic outcomes.

Current guidelines recommend against systematic screening for or treating asymptomatic bacteriuria (AB) among kidney transplant (KT) recipients, although the evidence regarding episodes occurring early after transplantation or in the presence of anatomical abnormalities is inconclusive. Oral fosfomycin may constitute a good option for the treatment of posttransplant AB, particularly due to the emergence of multidrug-resistant (MDR) uropathogens. Available clinical evidence supporting its use in this specific setting, however, remains scarce. We performed a retrospective study in 14 Spanish institutions from January 2005 to December 2017. Overall, 137 episodes of AB diagnosed in 133 KT recipients treated with oral fosfomycin (calcium and trometamol salts) with a test-of-cure urine culture within the first 30 days were included. Median time from transplantation to diagnosis was 3.1 months (interquartile range [IQR], 1.1 to 10.5). Most episodes (96.4% [132/137]) were caused by Gram-negative bacteria (GNB), and 56.9% (78/137) were categorized as MDR (extended‐spectrum β‐lactamase‐producing Enterobacterales [20.4%] and carbapenem‐resistant GNB [2.9%]). Rate of microbiological failure at month 1 was 40.1% (95% confidence interval [CI], 31.9% to 48.9%) for the whole cohort and 42.3% (95% CI, 31.2% to 54.0%) for episodes due to MDR pathogens. Previous urinary tract infection (odds ratio [OR], 2.42; 95% CI, 1.11 to 5.29; P value = 0.027) and use of fosfomycin as salvage therapy (OR, 8.31; 95% CI, 1.67 to 41.35; P value = 0.010) were predictors of microbiological failure. No severe treatment-related adverse events were detected. Oral fosfomycin appears to be a suitable and safe alternative for the treatment (if indicated) of AB after KT, including those episodes due to MDR uropathogens., This study was supported by Plan Nacional de I+D+i 2013‐2016 and Instituto de Salud Carlos III (ISCIII), Subdirección General de Redes y Centros de Investigación Cooperativa, Ministry of Science and Innovation, Spanish Network for Research in Infectious Diseases (REIPI RD16/0016), and Spanish Network for Research in Renal Diseases (REDInREN RD16/0009) and cofinanced by the European Development Regional Fund entitled A way to achieve Europe. M.F.-R. holds a research contract (Miguel Servet, CP18/00073), from the Spanish Ministry of Science and Innovation, ISCIII.

The COVID-19 pandemic has led to frequent referrals to the emergency department on suspicion of this infection in maintenance hemodialysis (MHD) and kidney transplant (KT) patients. We aimed to describe their clinical features comparing confirmed and suspected non-confirmed COVID-19 cases during the Spanish epidemic peak. Confirmed COVID-19 ((+)COVID-19) corresponds to patient with positive RT-PCR SARS-CoV-2 assay. Non-confirmed COVID-19 ((&minus, )COVID-19) corresponds to patients with negative RT-PCR. COVID-19 was suspected in 61 patients (40/803 KT (4.9%), 21/220 MHD (9.5%)). Prevalence of (+)COVID-19 was 3.2% in KT and 3.6% in MHD patients. Thirty-four (26 KT and 8 MHD) were (+)COVID-19 and 27 (14 KT and 13 MHD) (&minus, )COVID-19. In comparison with (&minus, )COVID-19 patients, (+)COVID-19 showed higher frequency of typical viral symptoms (cough, dyspnea, asthenia and myalgias), pneumonia (88.2% vs. 14.3%) and LDH and CRP while lower phosphate levels, need of hospital admission (100% vs. 63%), use of non-invasive mechanical ventilation (36% vs. 11%) and mortality (38% vs. 0%) (p &lt, 0.001). Time from symptoms onset to admission was longer in patients who finally died than in survivors (8.5 vs. 3.8, p = 0.007). In KT and MHD patients, (+)COVID-19 shows more clinical severity than suspected non-confirmed cases. Prompt RT-PCR is mandatory to confirm COVID-19 diagnosis.

The SARS‐Cov‐2 infection disease (COVID‐19) pandemic has posed at risk the kidney transplant (KT) population, particularly the elderly recipients. From March‐12th until April‐4th 2020, we diagnosed COVID‐19 in 16 of our 324 KT patients aged ≥65 years old (4.9%). Many of them had had contact with healthcare facilities in the month prior to infection. Median time of symptom onset to admission was 7 days. All presented with fever and all but one with pneumonia. Up to 33% showed renal graft dysfunction. At infection diagnosis, mTOR inhibitors or mycophenolate were withdrawn. Tacrolimus was withdrawn in 70%. The main treatment combination was hydroxychloroquine and azithromycin. A subset of patients was treated with anti‐retroviral and tocilizumab. Short‐term fatality rate was 50% at a median time since admission of 3 days. Those who died were more frequently obese, frail and had underlying heart disease. Although a higher respiratory rate was observed at admission in nonsurvivors, symptoms at presentation were similar between both groups. Patients who died were more anemic, lymphopenic and showed higher D‐dimer, C‐reactive protein, and IL‐6 at their first tests. COVID‐19 is frequent among the elderly KT population and associates a very early and high mortality rate.

Combination therapy is an attractive therapeutic option for extensively drug-resistant (XDR) Pseudomonas aeruginosa infections. Colistin has been the only treatment available for these infections for many years, but its results are suboptimal. Ceftolozane-tazobactam (C/T) is a newly available therapeutic option that has shown good antipseudomonal activity, even against a number of XDR P. aeruginosa strains. However, data about combinations containing C/T are scarce. The aim of this study was to analyze the activity of C/T and colistin alone and in combination against a collection of XDR P. aeruginosa strains containing 24 representative clinical isolates from a multicentre Spanish study. Twenty-four time-kill experiments performed over 24 h were conducted in duplicate to determine the effects of colistin and C/T alone and combined. An in vitro pharmacodynamic chemostat model then was used to validate this combination against three selected XDR P. aeruginosa ST175 isolates with different susceptibility levels to C/T. Static time-kill assays demonstrated superior synergistic or additive effect for C/T plus colistin against 21 of the 24 isolates studied. In the in vitro dynamic pharmacokinetic/pharmacodynamic (PK/PD) model, the C/T regimen of 2/1 g every 8 h with a steady-state concentration of 2 mg/liter colistin effectively suppressed the bacterial growth at 24 h. Additive or synergistic interactions were observed for C/T plus colistin against XDR P. aeruginosa strains and particularly against C/T-resistant strains. C/T plus colistin may be a useful treatment for XDR P. aeruginosa infections, including those caused by high risk-clones resistant to C/T.

Objectives: To analyze the clinical and economic burden of community-acquired (CA) or community-onset healthcare-associated (COHCA) multidrug-resistant (MDR) infections requiring hospitalization. Methods: Case-control study. Adults admitted with CA or COHCA MDR infections were considered cases, while those admitted in the same period with non-MDR infections were controls. The matching criteria were source of infection and/or microorganism. Primary outcome was 30-day clinical failure. Secondary outcomes were 90-day and 1-year mortality, hospitalization costs and resource consumption. Results: 194 patients (97 cases and 97 controls) were included. Multivariate analysis identified age (odds ratio [OR], 1.07, 95% confidence interval [CI], 1.01-1.14) and SOFA score (OR, 1.45, CI95%, 1.15-1.84) as independent predictors of 30-day clinical failure. Age (hazard ratio [HR] 1.09, 95%CI, 1.03-1.16) was the only factor associated with 90-day mortality, whereas age (HR 1.06, 95%CI, 1.03-1.09) and Charlson Index (HR 1.2, 95%CI, 1.07-1.34) were associated with 1-year mortality. MDR group showed longer hospitalization (p

This study assessed the molecular epidemiology, resistance mechanisms, and susceptibility profiles of a collection of 150 extensively drug-resistant (XDR) Pseudomonas aeruginosa clinical isolates obtained from a 2015 Spanish multicenter study, with a particular focus on resistome analysis in relation to ceftolozane-tazobactam susceptibility. Broth microdilution MICs revealed that nearly all (>95%) of the isolates were nonsusceptible to piperacillin-tazobactam, ceftazidime, cefepime, aztreonam, imipenem, meropenem, and ciprofloxacin. Most of them were also resistant to tobramycin (77%), whereas nonsusceptibility rates were lower for ceftolozane-tazobactam (31%), amikacin (7%), and colistin (2%). Pulsed-field gel electrophoresis–multilocus sequence typing (PFGE-MLST) analysis revealed that nearly all of the isolates belonged to previously described high-risk clones. Sequence type 175 (ST175) was detected in all 9 participating hospitals and accounted for 68% ( n = 101) of the XDR isolates, distantly followed by ST244 ( n = 16), ST253 ( n = 12), ST235 ( n = 8), and ST111 ( n = 2), which were detected only in 1 to 2 hospitals. Through phenotypic and molecular methods, the presence of horizontally acquired carbapenemases was detected in 21% of the isolates, mostly VIM (17%) and GES enzymes (4%). At least two representative isolates from each clone and hospital ( n = 44) were fully sequenced on an Illumina MiSeq. Classical mutational mechanisms, such as those leading to the overexpression of the β-lactamase AmpC or efflux pumps, OprD inactivation, and/or quinolone resistance-determining regions (QRDR) mutations, were confirmed in most isolates and correlated well with the resistance phenotypes in the absence of horizontally acquired determinants. Ceftolozane-tazobactam resistance was not detected in carbapenemase-negative isolates, in agreement with sequencing data showing the absence of ampC mutations. The unique set of mutations responsible for the XDR phenotype of ST175 clone documented 7 years earlier were found to be conserved, denoting the long-term persistence of this specific XDR lineage in Spanish hospitals. Finally, other potentially relevant mutations were evidenced, including those in penicillin-binding protein 3 (PBP3), which is involved in β-lactam (including ceftolozane-tazobactam) resistance, and FusA1, which is linked to aminoglycoside resistance.

Objective To describe a clonal outbreak due to vancomycin-resistant Enterococcus faecium (VREF) in the nephrology and renal transplant unit of a tertiary teaching hospital in Barcelona, Spain, and to highlight how active patient and environment surveillance cultures, as well as prompt and directed intervention strategies, mainly environmental, helped to successfully bring it under control. Patients and methods A study was conducted on patients admitted to the nephrology ward with any culture positive for VREF over a 6-month period (August 2012–January 2013). Based on the identification of a clonal link between the isolates, weekly rectal screening using swabs was implemented for all patients, as well as environmental cultures and cleaning of medical equipment and the ward. VREF isolates were identified by MicroScan and confirmed by Etest. Bacterial identification was confirmed by MALDI-TOF MS. The presence of van genes, and esp and hyl virulence genes was determined using PCR. The clonal relationship between the isolates was studied first with DiversiLab (bioMerieux), and then by PFGE-Smal and MLST. A two-tier sequence of infection control measures was implemented. Results During the study period, VREF was isolated from 13 patients. All cases were colonized with no criteria for infection. VREF isolates were also extensively recovered from the environment and medical equipment. Isolates carried the vanA gene, and were multidrug-resistant, including high-level resistance (MIC >16 mg/L) to vancomycin and teicoplanin. Molecular analysis showed that all VREF isolates belonged to sequence type 17 (ST17) carrying hyl virulence genes. After implementing infection control measures in a two-tier sequence, and reinforcing particularly environmental and medical equipment cleaning, no further cases were detected in the follow-up year. Conclusion A clonal outbreak of VREF-ST17 involving only colonization is reported. The prompt implementation of aggressive infection control measures in patients and the environment was effective in controlling the outbreak and avoided the potential emergence of infection among patients.

Background: Bloodstream infections are one of the main adverse effects of healthcare in Spain. In our hospital, we have reported that the mean incremental cost of patients who develop bacteremia during admission was €15,526 (US$18,314.62) per discharge, representing an annual increment in hospital cost of €1,108,190 (US$1,307,232) in 2005–2012. Moreover, we have also observed that only 15.4% of episodes of our bacteremia occur in intensive care units, with most of these infections (67%) occurring in conventional units.1 Therefore, we started several initiatives to reduce healthcare-associated bloodstream infections. Herein, we describe one of these initiatives, which is the implementation of the intravascular therapy team (ITT) and its effect on the observed healthcare-associated bloodstream infections. Methods: This retrospective analysis evaluated the incidence of healthcare-associated bloodstream infections in a University Hospital of 520 beds from January 2014 to June 2019. The ITT was implemented in 2017. This is a multidisciplinary team with 2 specialists in infection control and 2 specialists in intravascular therapy. We evaluated the annual incidence rate of healthcare-associated bloodstream infections (number of bacteremia episodes per 1,000 days of hospital stay) and its relation with the interventions carried out by the multidisciplinary team. Results: The annual incidences of healthcare-associated bloodstream infections (episodes per 1,000 days of hospital stay) were 0.50 (2014), 0.46 (2015), 0.58 (2016), 0.69 (2017), 0.60 (2018), 0.51 (first quarter 2019), and 0.38 (second quarter 2019, 0.38), respectively. The highest incidence of bacteremia was observed in 2017 when the ITT started the following actions: (1) following a clinical protocol to improve the appropriateness in the utilization of new devices such as a peripherally inserted central catheter (PICC) and Medline; (2) continuous training of healthcare professionals, particularly young staff; (3) feedback with hospitalization units; and (4) proactive surveillance of venous access manipulation and maintenance. The interventions were designed, implemented, and evaluated by the ITT and were well accepted by healthcare professionals. After the implementation of the ITT, the incidence of healthcare-associated bloodstream infections decreased. This trend was particularly relevant for parenteral nutrition catheters (episodes per 1,000 days of parenteral nutrition) (Fig. 1). Conclusions: The implementation of the ITT in our center has allowed us to considerably reduce the incidence of healthcare-associated bloodstream infections. From our experience, the interventions related to systematic evaluation, education, and feedback are key to obtain and maintain this improvement.Funding: NoneDisclosures: Carlota Hidalgo-Lopez reports that this study was partly funded by Diversey. The authors did not receive direct Funding: from the sponsor, Juan Pablo Horcajada reports consulting fees from MSD, Pfizerand, and Menarini, as well as speaker fees from MSD, Pfizer, and Zambon.

y In recent years, the worldwide spread of the so-called high-risk clones of multidrug-resistant or extensively drug-resistant (MDR/XDR) Pseudomonas aeruginosa has become a public health threat. This article reviews their mechanisms of resistance, epidemiology, and clinical impact and current and upcoming therapeutic options. In vitro and in vivo treatment studies and pharmacokinetic and pharmacodynamic (PK/PD) models are discussed. Polymyxins are reviewed as an important therapeutic option, outlining dosage, pharmacokinetics and pharmacodynamics, and their clinical efficacy against MDR/XDR P. aeruginosa infections. Their narrow therapeutic window and potential for combination therapy are also discussed. Other "old" antimicrobials, such as certain beta-lactams, aminoglycosides, and fosfomycin, are reviewed here. New antipseudomonals, as well as those in the pipeline, are also reviewed. Ceftolozane-tazobactam has clinical activity against a significant percentage of MDR/XDR P. aeruginosa strains, and its microbiological and clinical data, as well as recommendations for improving its use against these bacteria, are described, as are those for ceftazidime-avibactam, which has better activity against MDR/XDR P. aeruginosa, especially strains with certain specific mechanisms of resistance. A section is devoted to reviewing upcoming active drugs such as imipenem-relebactam, cefepime-zidebactam, cefiderocol, and murepavadin. Finally, other therapeutic strategies, such as use of vaccines, antibodies, bacteriocins, anti-quorum sensing, and bacteriophages, are described as future options.

A two-compartment pharmacokinetic (PK) population model of anidulafungin was fitted to PK data from 23 critically ill patients (age, 65 years [range, 28 to 81 years]; total body weight [TBW], 75 kg [range, 54 to 168 kg]). TBW was associated with clearance and incorporated into a final population PK model. Simulations suggested that patients with higher TBWs had less-extensive MIC coverage. Dosage escalation may be warranted in patients with high TBWs to ensure optimal drug exposures for treatment of Candida albicans and Candida glabrata infections.

Summary Objectives Optimal dosage regimens of colistin for the treatment of urinary tract infections (UTI) are unknown. Colistimethate sodium (CMS), the inactive prodrug of colistin, is mainly excreted in urine and converts to colistin after filtration by glomeruli, suggesting that concentrations of colistin in urine could be much higher than in plasma. Therefore, there is a need to optimize dosage regimens of intravenous CMS for UTI. The aim of this study was to examine the relationship between AUC/MIC of formed colistin and clinical outcomes in patients with UTI caused by extremely drug resistant (XDR) Pseudomonas aeruginosa. Methods This prospective, observational cohort study involved patients with UTI caused by XDR P. aeruginosa. Clinical cure, bacteriological clearance and acute kidney injury (AKI) were analyzed. Steady-state colistin plasma concentrations (Css) were measured using HPLC. Based on the PK/PD of colistin in neutropenic mouse thigh infection models with P. aeruginosa, the optimal AUC/MIC should be ≥60 mg·h/L. According to the pharmacokinetics (PK) in critically-ill patients, the Css target of formed colistin in plasma was 2.5 mg/L. Results Thirty-three patients were included (24 lower UTI and 9 pyelonephritis). The MIC50 and MIC90 values for colistin were 0.5 and 2 mg/L respectively. Nineteen patients (57.6%) received colistin monotherapy (84.2% lower UTI and 15.8% pyelonephritis). Of these, clinical cure was achieved in 89.5% of cases. Among patients with clinical cure and monotherapy, only 5 (29.4%) attained an optimal plasma AUC/MIC and only 1 (5.9%) the therapeutic level of formed colistin (2.5 mg/L). However, 10 (58.8%) patients showed colistin plasma concentrations above the MIC of the isolated P. aeruginosa. Microbiological eradication was achieved in 76.9% of patients. AKI at the end of treatment was present in 29.4% of patients. Conclusions The currently recommended dosage regimens of CMS showed high efficacy for the treatment of lower complicated UTI caused by XDR P. aeruginosa in non-critically ill patients and in the case of low MIC values, but also a considerable nephrotoxicity rate. Our data suggest that the use of lower CMS doses for lower UTI should be investigated in future studies to minimize the unnecessary nephrotoxicity.

Background: Extensively drug-resistant (XDR) Pseudomonas aeruginosa (P. aeruginosa) and particularly P. aeruginosa high-risk clones, are of growing concern because treatment options are limited. For years, colistin monotherapy has been the only available treatment, but is well known that is not an optimal treatment. A combination of colistin with another antibiotic could be a possible therapeutic option. Objectives: This study aimed to investigate effective antibiotic combinations against 20 XDR P. aeruginosa isolates obtained in a Spanish multicentre study (2015). Methods: Forty-five checkerboards with six antipseudomonal antibiotics (amikacin, aztreonam, ceftazidime, meropenem, colistin, and ceftolozane/tazobactam) were performed to determine whether combinations were synergic or additive by fractional inhibitory concentration indices. On average, 15 different regimens were evaluated in duplicate against the three most prevalent high-risk clones (ST175, ST235, ST111) by time-kill analyses over 24 h. The combination showing synergism in the three high-risk clones was validated in all studied XDR isolates. Results: In time-kill curves, the untreated control failed, as did each study regimen when administered alone. Two combinations were synergistic in the three high-risk clones that were initially studied: amikacin plus ceftazidime and colistin plus meropenem, with the second being the most effective combination. The efficacy of colistin plus meropenem was then tested in all 20 isolates. A synergistic bacterial density reduction for the duration of the study occurred in 80% of the entire XDR collection. Conclusions: These data suggest that colistin plus meropenem may be a useful combination for the treatment of infections due to XDR P. aeruginosa, including high-risk clones, which warrants evaluation in a clinical trial. (C) 2019 International Society for Antimicrobial Chemotherapy. Published by Elsevier Ltd. All rights reserved.

Colistin is administered as its inactive prodrug colistimethate (CMS). Selection of an individualized CMS dose for each patient is difficult due to its narrow therapeutic window, especially in patients with chronic kidney disease (CKD). Our aim was to analyze CMS use in patients with CKD. Secondary objectives were to assess the safety and efficacy of CMS in this special population. In this prospective observational cohort study of CMS-treated CKD patients, CKD was defined as the presence of a glomerular filtration rate (GFR) &lt, 60 mL/min/m2 for more than 3 months. The administered doses of CMS were compared with those recently published in the literature. Worsened CKD at the end of treatment (EOT) was evaluated with the RIFLE (Risk, Injury, Failure, Loss of kidney function, and End-stage kidney disease) criteria. Colistin plasma concentrations (Css) were measured using high-performance liquid chromatography. Fifty-nine patients were included. Thirty-six (61.2%) were male. The median age was 76 (45&ndash, 95) years and baseline GFR was 36.6 &plusmn, 13.6. The daily mean CMS dosage used was compared with recently recommended doses (3.36 vs. 6.07, p &lt, 0.001). Mean Css was 0.9 (0.2&ndash, 2.9) mg/L, and Css was &lt, 2 mg/L in 50 patients (83.3%). Clinical cure was achieved in 43 (72.9%) patients. Worsened renal function at EOT was present in 20 (33.9%) patients and was reversible in 10 (52.6%). The CMS dosages used in this cohort were almost half those currently recommended. The mean achieved Css were under the recommended target of 2 mg/dL. Despite this, clinical cure rate was high. In this patient cohort, the incidence of nephrotoxicity was similar to those found in other recent studies performed in the general population and was reversible in 52.6%. These results suggest that CMS is safe and effective in patients with CKD and may encourage physicians to adjust dosage regimens to recent recommendations in order to optimize CMS treatments.

Background Cytomegalovirus infection dramatically decreased with the introduction of antiretroviral therapy. Whether incidence, clinical characteristics and prognosis of cytomegalovirus in HIV infected patients, has changed over time is. scarcely known. Methods Retrospective single-center study. Patients included in this study were all HIV infected patients that went to our center for any disease, and were diagnosed with cytomegalovirus, during the period 2004–2015. epidemiological, clinical and laboratory patients variables were collected in a clinical database. Clinical characteristics, incidence of cytomegalovirus and predictors of mortality during the study were assessed. Results were considered statistically significant when p Results Fifty-six cases of cytomegalovirus infection, in HIV infected patients were identified during the study period (incidence rate-1.7 cases per 1000 persons/year). The most frequent presentation was systemic illness in 43% of cases. Of note,no patients presented with ophthalmic manifestations. The 30-days mortality was 18%. Predictors of mortality were, in the univariate analysis, admission to the intensive care unit OR 32.4 (3.65–287.06) p = 0.0001, and mechanic ventilation 84 OR (8.27–853.12) p = 0.0001, and ART OR 4.1 (0.97–17.31) p = 0.044. These variables were assessed by multivariate analysis, and only mechanical ventilation was statistically significant (p Conclusion Incidence of cytomegalovirus infection was higher than described in the antiretroviral therapy era. Clinical presentation has changed. Mechanic ventilation predicted mortality.

Background To determine the risk of hospital readmission and associated factors in patients with a positive sample for multidrug-resistant microorganisms (MRM) and to analyze whether there is a higher risk of hospital readmission with some of the more common MRM. Methods Retrospective cohort study (2012–16) performed in a tertiary-care teaching hospital in Barcelona. Patients were divided into two groups, depending on the presence or absence of an MRM-positive sample during hospital admission. Logistic regression models were used to estimate the risk of hospital readmission in the first 30 and 90 days, and the first year for patients with an MRM-positive sample compared with those without. The models were stratified by the presence or absence of an MRM-positive sample and by grouped Charlson comorbidity index. Results We included 983 patients with an MRM-positive sample and 39 323 patients without. The risk of hospital readmission in the first 30 days was 41% higher in admitted patients with an MRM-positive sample (95%CI=1.17 to 1.69) than in those without. Stratified models showed similar results to the overall results for all Charlson comorbidity index groups. When the models were stratified by the presence of an MRM-positive sample, methicillin-resistant Staphylococcus aureus showed the highest risk of readmissions within the more common MRM [103% (95%CI=1.10 to 3.75)]. Conclusion MRMs seem to be an important risk factor for hospital readmissions both among patients with and without comorbidities. Specific types of MRM may represent a higher risk for hospital readmissions than other MRMs, depending on the particular environment or hospital.

Cardiovascular risk (CVR) assessment helps to identify patients at high CVR. The Framingham CVR score (FRS) is the most widely used methods but may overestimate risk in regions with low incidence of cardiovascular disease. The objective was to compare the 10-year performance of the original and the adapted REGICOR - Framingham CVR functions in HIV-infected individuals.We carried out a longitudinal study of HIV-infected patients with CVR evaluation in a hospital in Barcelona between 2003 and 2013.Risk probability was calculated using the FRAMINGHAM function and REGICOR adaptation to the Spanish population, and individuals were categorized in three groups (low, 0 5%; moderate, 5-10%; and high,10%). For each risk group, the number of events over 10 years was calculated using the Kaplan-Meier method, and the expected number of events was calculated by multiplying the frequency of participants in the group by the mean of the probabilities from the risk function. We used the X(2) goodness-of-fit test to assess agreement between observed and expected.Six hundred and forty-one patients were followed up for a median of 10.2 years, and 20 ischemic heart events (IHE) were observed. The mean (95% CI) number of IHEs per 1000 person-years was 3.7 (2.06-5.27). The estimates from the Framingham and REGICOR functions were 40 and 14 IHEs, respectively. The estimate from the original Framingham function differed significantly from the observed incidence (p 0.001), whereas that from the REGICOR-adapted function did not (p = 0.15). In terms of the number of cardiovascular events (38 events observed), the REGICOR function significantly underestimated risk (p = 0.01), whereas the estimate from the Framingham function was similar to observed (p:0.93).The FRS significantly overestimates risk of IHE events in our HIV-infected patients, while the REGICOR function is a better predictor of these events. In terms of cardiovascular events, the REGICOR function significantly underestimates risk, whereas the FRS is a better estimator. We recommend using CVR scales and adjusting them to the origin of the population being studied.

This study aimed to assess the impact of extensively drug-resistant (XDR) phenotype on mortality in Pseudomonas aeruginosa bacteremia. A retrospective cohort study was performed in a tertiary hospital from January 2000 to December 2018. All consecutive prospectively recorded P. aeruginosa bacteremia in adult patients were assessed. In this study, 382 patients were included, of which 122 (31.9%) due to XDR P. aeruginosa. Independent factors associated with 14-day mortality were as follows: high-risk source of bacteremia (hazard ratio (HR) 3.07, 95% confidence interval (CI), 1.73&ndash, 5.46), septic shock (HR 1.75, 95% CI, 1.12&ndash, 2.75), and higher Pitt scores (one-point increments, HR 1.25, 95% CI, 1.12&ndash, 1.38). Otherwise, the appropriateness of definitive antibiotic therapy was a protective factor (HR 0.39, 95% CI, 0.24&ndash, 0.62). The same variables were also associated with 30-day mortality. XDR phenotype was not associated with 14- or 30-day mortality. In a subanalysis considering only high-risk source cases, combined antimicrobial therapy was independently associated with 14-day favorable outcome (HR 0.56, 95% CI, 0.33&ndash, 0.93). In conclusion, XDR phenotype was not associated with poor prognosis in patients with P. aeruginosa bacteremia in our cohort. However, source of infection, clinical severity, and inappropriate definitive antibiotic therapy were risk factors for mortality. Combined antimicrobial therapy should be considered for high-risk sources.

Nephrotoxicity limits the effective use of colistin for the treatment of multidrug-resistant Gram-negative bacteria (MDR-GNB) infections. We previously defined a steady-state colistin plasma concentration (C-ss) of 2.42 mg/L that predicted nephrotoxicity at end of treatment (EOT). The objective of this study was to validate this breakpoint in a prospective cohort. This was a multicentre, prospective, observational study conducted at three hospitals with a cohort of patients treated for MDR-GNB infection with colistin methanesulfonate from September 2011 until January 2015. Nephrotoxicity was evaluated at Day 7 and at EOT using the RIFLE criteria. C-ss values were measured and analysed using HPLC. Taking the previously defined breakpoint for colistin concentration as a criterion, patients were divided into two groups (C-ss, 2.42 mg/L). Sixty-four patients were included. Seven patients (10.9%) had a C-ss > 2.42 mg/L and were compared with the remaining patients. Bivariate analysis showed that patients with a C-ss > 2.42 mg/L were older and had a significantly higher incidence of nephrotoxicity at Day 7 and EOT. Although not statistically significant, nephrotoxicity occurred earlier in these patients (6.2 days vs. 9.2 days in patients with lower C-ss; P = 0.091). Multivariate analysis of nephrotoxicity showed that C-ss > 2.42 mg/L was the only predictive factor. Nephrotoxicity was more frequent and occurred earlier in patients with colistin plasma concentrations higher than the previously defined breakpoint (2.42 mg/L). Colistin therapeutic drug monitoring should be routinely considered to avoid reaching this toxicity threshold and potential clinical consequences. (C) 2016 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

The aim of this study was to investigate the efficacy of ceftolozane-tazobactam in combination with meropenem against an extensively drug-resistant (XDR) Pseudomonas aeruginosa high-risk clone, sequence type 175, isolated in a Spanish university hospital. A 14-day hollow-fiber infection model was used to simulate clinical exposure of the two drug regimens alone and in combination, and serial samples were collected to determine drug concentrations and CFU counts. The untreated control failed, as did each study regimen when administered alone. However, when ceftolozane-tazobactam was administered in combination with meropenem, there was a >4-log 10 CFU/ml bacterial density reduction and suppression of resistance for the duration of the study. These data suggest that ceftolozane-tazobactam plus meropenem may be a useful combination for treating XDR P. aeruginosa .

This study assessed the molecular epidemiology, resistance mechanisms, and susceptibility profiles of a collection of 150 extensively drug-resistant (XDR) Pseudomonas aeruginosa clinical isolates obtained from a 2015 Spanish multicenter study, with a particular focus on resistome analysis in relation to ceftolozane-tazobactam susceptibility. Broth microdilution MICs revealed that nearly all (>95%) of the isolates were nonsusceptible to piperacillin-tazobactam, ceftazidime, cefepime, aztreonam, imipenem, meropenem, and ciprofloxacin. Most of them were also resistant to tobramycin (77%), whereas nonsusceptibility rates were lower for ceftolozane-tazobactam (31%), amikacin (7%), and colistin (2%). Pulsed-field gel electrophoresis–multilocus sequence typing (PFGE-MLST) analysis revealed that nearly all of the isolates belonged to previously described high-risk clones. Sequence type 175 (ST175) was detected in all 9 participating hospitals and accounted for 68% (n = 101) of the XDR isolates, distantly followed by ST244 (n = 16), ST253 (n = 12), ST235 (n = 8), and ST111 (n = 2), which were detected only in 1 to 2 hospitals. Through phenotypic and molecular methods, the presence of horizontally acquired carbapenemases was detected in 21% of the isolates, mostly VIM (17%) and GES enzymes (4%). At least two representative isolates from each clone and hospital (n = 44) were fully sequenced on an Illumina MiSeq. Classical mutational mechanisms, such as those leading to the overexpression of the β-lactamase AmpC or efflux pumps, OprD inactivation, and/or quinolone resistance-determining regions (QRDR) mutations, were confirmed in most isolates and correlated well with the resistance phenotypes in the absence of horizontally acquired determinants. Ceftolozane-tazobactam resistance was not detected in carbapenemase-negative isolates, in agreement with sequencing data showing the absence of ampC mutations. The unique set of mutations responsible for the XDR phenotype of ST175 clone documented 7 years earlier were found to be conserved, denoting the long-term persistence of this specific XDR lineage in Spanish hospitals. Finally, other potentially relevant mutations were evidenced, including those in penicillin-binding protein 3 (PBP3), which is involved in β-lactam (including ceftolozane-tazobactam) resistance, and FusA1, which is linked to aminoglycoside resistance.

Summary Background Our objective was to assess therapeutic non-inferiority of dual treatment with lopinavir–ritonavir and lamivudine to triple treatment with lopinavir–ritonavir plus two nucleos(t)ides for maintenance of HIV-1 viral suppression. Methods In this randomised, open-label, non-inferiority trial, we recruited patients from 32 HIV units in hospitals in Spain and France. Eligible patients were HIV-infected adults (aged ≥18 years) with HIV-1 RNA of less than 50 copies per mL, for at least 6 months on triple treatment with lopinavir–ritonavir (twice daily) plus lamivudine or emtricitabine and a second nucleos(t)ide, with no resistance or virological failure to these drugs, and no positive hepatitis B serum surface antigen. Investigators at each centre randomly assigned patients (1:1; block size of four; stratified by time to suppression [ 1 year] and nadir CD4 cell count [ 100 cells per μL]; computer-generated random sequence) to continue triple treatment or switch to dual treatment (oral lopinavir 400 mg and oral ritonavir 100 mg twice daily plus oral lamivudine 300 mg once daily). The primary endpoint was response to treatment in the intention-to-treat population (all randomised patients) at 48 weeks. The non-inferiority margin was 12%. This study is registered with ClinicalTrials.gov, number NCT01471821. Findings Between Oct 1, 2011, and April 1, 2013, we randomly assigned 250 participants to continue triple treatment (127 [51%] patients) or switch to dual treatment (123 [49%] patients). In the intention-to-treat population, 110 (86·6%) of 127 patients in the triple-treatment group responded to treatment versus 108 (87·8%) of 123 in the dual-treatment group (difference −1·2% [95% CI −9·6 to 7·3]; p=0·92), meeting the criteria for non-inferiority. Serious adverse events occurred in eight (7%) patients in the triple-treatment group and five (4%) in the dual-treatment group (p=0·515), and study drug discontinuations due to adverse events occurred in four (3%) in the triple-treatment group and one (1%) in the dual-treatment group (p=0·223). Interpretation Dual treatment with lopinavir–ritonavir plus lamivudine has non-inferior therapeutic efficacy and is similarly tolerated to triple treatment. Funding AbbVie and Red Tematica Cooperativa de Investigacion en Sida.

BACKGROUND Microbial translocation has been associated with an increase in immune activation and inflammation in HIV infection despite effective highly active antiretroviral therapy. It has been shown that some probiotics have a beneficial effect by reducing intestinal permeability and, consequently, microbial translocation. OBJECTIVES To assess changes in microbial translocation and inflammation after treatment with probiotics (Saccharomyces boulardii) in HIV-1-infected patients with virologic suppression. METHODS A double-blind, randomized, placebo-controlled trial was conducted in 44 nonconsecutive HIV-1-infected patients with viral load of

OBJECTIVES: Interactions between antiretroviral treatment (ART) and comedications are a concern in HIV-infected patients. This study aimed to determine the frequency and severity of potential drug-drug interactions (PDDIs) with ART in our setting. METHODS: Observational study by a multidisciplinary team in 1259 consecutive HIV patients (March 2015-September 2016). Data on demographics, toxic habits, comorbidities, and current ART were collected. A structured questionnaire recorded concomitant medications (including occasional and over-the-counter drugs). PDDIs were classified into four categories: (1) no interactions, (2) mild (clinically non-significant), (3) moderate (requiring close monitoring or drug modification/dose adjustment), and (4) severe (contraindicated). STATISTICAL ANALYSIS: chi-square test, logistic regression analysis. RESULTS: In total, 881 (70%) patients took comedication, and 563 (44.7%) had ≥ PDDI. Forty-one comedicated patients (4.6%) had severe and 522 (59.2%) moderate PDDIs. Moderate PDDIs mainly involved cardiovascular (53.8%) and central nervous system (40.2%) drugs. Independent risk factors for PDDIs were ART containing a boosted protease inhibitor (odds ratio [OR]=9.11, 95% confidence interval [CI] 5.15-16.11; p = 0.0001) and/or non-nucleoside reverse transcriptase (NNRTI) (OR = 4.34, 95%CI 2.49-7.55; p = 0.0001), HCV co-infection (OR = 3.26, 95%CI 2.15-4.93; p = 0.0001), and use of two or more comedications (OR = 3.36, 95%CI 2.27-4.97; p = 0.0001). Adherence and effectiveness of ART were similar in patients with and without PDDIs. The team made 133 recommendations related to comedications (drug change or dose adjustment) or ART (drug switch or change in administration schedule). CONCLUSIONS: Systematic evaluation detected a significant percentage of PDDIs requiring an intervention in HIV patients on ART. Monitoring and advice about drug-drug interactions should be part of routine practice.

Objectives The aim of the study was to investigate whether very low level viraemia (VLLV) (20-50 HIV-1 RNA copies/mL) was associated with increased risk of virological failure (VF) as compared with persistent full suppression (< 20 copies/mL). Methods From the VACH Cohort database, we selected those patients who started antiretroviral therapy (ART) after January 1997 and who achieved effective viral suppression [two consecutive viral loads (VLs) < 50 copies/mL] followed by full suppression (at least one VL < 20 copies/mL). We carried out survival analyses to investigate whether the occurrence of VLLV rather than maintaining full suppression at < 20 copies/mL was associated with virological failure (two consecutive VLs > 200 copies/mL or one VL > 200 copies/mL followed by a change of ART regimen, administrative censoring or loss to follow-up), adjusted for nadir CD4 cell count, sex, age, ethnicity, transmission group, type of ART and time on effective suppression at < 50 copies/mL. Results Of 21 480 patients who started ART, 13 674 (63.7%) achieved effective suppression at < 50 copies/mL, of whom 4289 (31.4%) further achieved full suppression at < 20 copies/mL after May 2009. A total of 2623 patients (61.1%) remained fully suppressed thereafter, while 1666 had one or more episodes of VL detection > 20 copies/mL (excluding virological failure). A total of 824 patients had VLLV after suppression at < 20 copies/mL. VLLV was not associated with virological failure as compared with persistent full suppression [hazard ratio (HR) 0.67; 95% confidence interval (CI) 0.44-1.00], independently of the number of blips recorded (from one to 18). Conclusions In our population of HIV-infected patients on ART who achieved viral suppression at < 20 copies/mL, the risk of virological failure was no different for patients who remained fully suppressed compared with those who experienced subsequent episodes of VLLV.