Genome-based comparison between the recombinant SARS-CoV-2 XBB and its parental lineages.

Recombination is the main contributor to RNA virus evolution, and SARS-CoV-2 during the pandemic produced several recombinants. The most recent SARS-CoV-2 recombinant is the lineage labeled XBB, also known as Gryphon, which arose from BJ.1 and BM.1.1.1. Here we performed a genome-based survey aimed to compare the new recombinant with its parental lineages that never became dominant. Genetic analyses indicated that the recombinant XBB and its first descendant XBB.1 show an evolutionary condition typical of an evolutionary blind background with no further epidemiologically relevant descendant. Genetic variability and expansion capabilities are slightly higher than parental lineages. Bayesian Skyline Plot indicates that XBB reached its plateau around October 6, 2022 and after an initial rapid growth the viral population size did not further expand, and around November 10, 2022 its levels of genetic variability decreased. Simultaneously with the reduction of the XBB population size, an increase of the genetic variability of its first sub-lineage XBB.1 occurred, that in turn reached the plateau around November 9, 2022 showing a kind of vicariance with its direct progenitors. Structure analysis indicates that the affinity for ACE2 surface in XBB/XBB.1 RBDs is weaker than for BA.2 RBD. In conclusion, at present XBB and XBB.1 do not show evidence about a particular danger or high expansion capability. Genome-based monitoring must continue uninterrupted to individuate if further mutations can make XBB more dangerous or generate new subvariants with different expansion capability.

The SARS-CoV-2 Mu variant should not be left aside: It warrants attention for its immuno-escaping ability.

The COVID-19 pandemic continues to have a threatening impact on a global scale, largely due to the emergence of newly SARS-CoV-2 variants. The Mu (PANGO lineage B.1.621), was first identified in Colombia in January 2021 and was classified as a variant of interest (VOI) in August 2021, due to a constellation of mutations that likely-mediate an unexpectedly enhanced immune resistance to inactivated vaccine-elicited antibodies. Despite recent studies suggesting that the Mu variant appears to have less infectivity than the Delta variant, here we examined the structural effect of the Mu spike protein mutations and predicted the potential impact on infectivity of the Mu variant compared with the Delta and Delta plus spike protein.

Genetic and Structural Data on the SARS-CoV-2 Omicron BQ.1 Variant Reveal Its Low Potential for Epidemiological Expansion.

The BQ.1 SARS-CoV-2 variant, also known as Cerberus, is one of the most recent Omicron descendant lineages. Compared to its direct progenitor BA.5, BQ.1 has some additional spike mutations in some key antigenic sites, which confer further immune escape ability over other circulating lineages. In such a context, here, we perform a genome-based survey aimed at obtaining a complete-as-possible nuance of this rapidly evolving Omicron subvariant. Genetic data suggest that BQ.1 represents an evolutionary blind background, lacking the rapid diversification that is typical of a dangerous lineage. Indeed, the evolutionary rate of BQ.1 is very similar to that of BA.5 (7.6 × 10-4 and 7 × 10-4 subs/site/year, respectively), which has been circulating for several months. The Bayesian Skyline Plot reconstruction indicates a low level of genetic variability, suggesting that the peak was reached around 3 September 2022. Concerning the affinity for ACE2, structure analyses (also performed by comparing the properties of BQ.1 and BA.5 RBD) indicate that the impact of the BQ.1 mutations may be modest. Likewise, immunoinformatic analyses showed moderate differences between the BQ.1 and BA5 potential B-cell epitopes. In conclusion, genetic and structural analyses on SARS-CoV-2 BQ.1 suggest no evidence of a particularly dangerous or high expansion capability. Genome-based monitoring must continue uninterrupted for a better understanding of its descendants and all other lineages.

Ceftazidime-Avibactam Use for Klebsiella pneumoniae Carbapenemase-Producing K. pneumoniae Infections: A Retrospective Observational Multicenter Study.

BACKGROUND: A growing body of observational evidence supports the value of ceftazidime-avibactam (CAZ-AVI) in managing infections caused by carbapenem-resistant Enterobacteriaceae. METHODS: We retrospectively analyzed observational data on use and outcomes of CAZ-AVI therapy for infections caused by Klebsiella pneumoniae carbapenemase-producing K. pneumoniae (KPC-Kp) strains. Multivariate regression analysis was used to identify variables independently associated with 30-day mortality. Results were adjusted for propensity score for receipt of CAZ-AVI combination regimens versus CAZ-AVI monotherapy. RESULTS: The cohort comprised 577 adults with bloodstream infections (n = 391) or nonbacteremic infections involving mainly the urinary tract, lower respiratory tract, and intra-abdominal structures. All received treatment with CAZ-AVI alone (n = 165) or with ≥1 other active antimicrobials (n = 412). The all-cause mortality rate 30 days after infection onset was 25% (146/577). There was no significant difference in mortality between patients managed with CAZ-AVI alone and those treated with combination regimens (26.1% vs 25.0%, P = .79). In multivariate analysis, mortality was positively associated with presence at infection onset of septic shock (P = .002), neutropenia (P < .001), or an INCREMENT score ≥8 (P = .01); with lower respiratory tract infection (LRTI) (P = .04); and with CAZ-AVI dose adjustment for renal function (P = .01). Mortality was negatively associated with CAZ-AVI administration by prolonged infusion (P = .006). All associations remained significant after propensity score adjustment. CONCLUSIONS: CAZ-AVI is an important option for treating serious KPC-Kp infections, even when used alone. Further study is needed to explore the drug's seemingly more limited efficacy in LRTIs and potential survival benefits of prolonging CAZ-AVI infusions to ≥3 hours.

Missed linkage to care for patients who screened positive for Hepatitis C in a tertiary care centre: Results of the Telepass project.

Italy is one of the countries on track with the WHO's agenda to eliminate hepatitis C virus (HCV) by 2030. Healthcare facilities play a crucial role in seeking patients who are infected but have not yet been treated. We assessed the effectiveness of a recall strategy, named 'Telepass' project, for patients exposed to HCV infection who have not yet been linked to care in a large tertiary care centre. The 'Telepass' project was structured in two phases: (a) a retrospective analysis first identified all anti-HCV-positive subjects among patients who underwent pre-operative assessment in the facility in the course of one year; (b) a following prospective phase, aimed to recall patients in need either of further diagnostic tests (ie HCV-RNA) or treatment. A total of 12246 records of patients tested for HCV antibodies were reviewed. The overall prevalence of anti-HCV-positive subjects was 1.83% (224/12246) with a male/female ratio of 2.07. Out of the 224 anti-HCV-positive patients, 123 (54.91%) did not have documented HCV-RNA tests and were therefore selected for recall. Of these, 123 were reachable and 26 (21.13%) were successfully linked to care. Ten patients (38.46%) tested HCV-RNA positive and initiated treatment with direct-acting antivirals (DAAs). The Telepass study highlights that a recall strategy starting from internal hospital databases can help identify patients with chronic HCV infection who have not yet been linked to care, and provides an epidemiological insight into the prevalence of HCV infection in Italy in the late DAAs era.

SARS-CoV-2 B.1.617 Indian variants: Are electrostatic potential changes responsible for a higher transmission rate?

Lineage B.1.617+, also known as G/452R.V3 and now denoted by WHO with the Greek letters δ and κ, is a recently described SARS-CoV-2 variant under investigation first identified in October 2020 in India. As of May 2021, three sublineages labeled as B.1.617.1 (κ), B.1.617.2 (δ), and B.1.617.3 have been already identified, and their potential impact on the current pandemic is being studied. This variant has 13 amino acid changes, three in its spike protein, which are currently of particular concern: E484Q, L452R, and P681R. Here, we report a major effect of the mutations characterizing this lineage, represented by a marked alteration of the surface electrostatic potential (EP) of the receptor-binding domain (RBD) of the spike protein. Enhanced RBD-EP is particularly noticeable in the B.1.617.2 (δ) sublineage, which shows multiple replacements of neutral or negatively charged amino acids with positively charged amino acids. We here hypothesize that this EP change can favor the interaction between the B.1.617+ RBD and the negatively charged ACE2, thus conferring a potential increase in the virus transmission.

Evolution of cellular HIV DNA levels in virologically suppressed patients switching to dolutegravir/lamivudine versus maintaining a triple regimen: a prospective, longitudinal, matched, controlled study.

OBJECTIVES: To assess the impact of switching to dolutegravir plus lamivudine maintenance therapy on the HIV cellular reservoir size. PATIENTS AND METHODS: This was a prospective, longitudinal, matched, controlled study. We enrolled virologically suppressed patients on stable three-drug ART who switched at baseline (BL) to dolutegravir/lamivudine (DT group) or maintained triple therapy (TT group); subjects in the TT group were matched 1:1 with those in the DT group according to age, gender, years since HIV diagnosis, years on ART and anchor drug. Total blood-associated HIV DNA levels were assessed by droplet digital PCR at BL and after 48 weeks (T48). Results were expressed as log10 HIV DNA copies/106 leucocytes. RESULTS: We enrolled 40 patients in the DT group and 40 in the TT group; the two groups were homogeneous for all main characteristics except nadir CD4 cell count. At BL, HIV DNA levels were comparable between the DT and TT groups: 2.27 (IQR 1.97-2.47) and 2.26 (IQR 2.05-2.61) log10 HIV DNA copies/106 leucocytes, respectively. Change in HIV DNA load from BL to T48 was -0.105 (IQR -0.384 to 0.121, P = 0.041) in the DT group and -0.132 (IQR -0.362 to 0.046, P = 0.005) in the TT group, with a comparable decline observed between the two groups (P = 0.821). A higher HIV DNA decline was associated with higher BL CD4/CD8 ratio. CONCLUSIONS: Maintenance therapy with dolutegravir/lamivudine had the same impact as the triple regimen on HIV DNA levels after 48 weeks of treatment. These data seem to support the effectiveness of a dolutegravir/lamivudine dual regimen in controlling the magnitude of the cellular reservoir (www.clinicaltrials.gov, number NCT02836782).

White Paper: Bridging the gap between surveillance data and antimicrobial stewardship in the outpatient sector-practical guidance from the JPIAMR ARCH and COMBACTE-MAGNET EPI-Net networks.

BACKGROUND: The outpatient setting is a key scenario for the implementation of antimicrobial stewardship (AMS) activities, considering that overconsumption of antibiotics occurs mainly outside hospitals. This publication is the result of a joint initiative by the JPIAMR ARCH and COMBACTE-MAGNET EPI-Net networks, which is aimed at formulating a set of target actions for linking surveillance data with AMS activities in the outpatient setting. METHODS: A scoping review of the literature was carried out in three research areas: AMS leadership and accountability; antimicrobial usage and AMS; antimicrobial resistance and AMS. Consensus on the actions was reached through a RAND-modified Delphi process involving over 40 experts in infectious diseases, clinical microbiology, AMS, veterinary medicine or public health, from 18 low-, middle- and high-income countries. RESULTS: Evidence was retrieved from 38 documents, and an initial 25 target actions were proposed, differentiating between essential or desirable targets according to clinical relevance, feasibility and applicability to settings and resources. In the first consultation round, preliminary agreement was reached for all targets. Further to a second review, 6 statements were re-considered and 3 were deleted, leading to a final list of 22 target actions in the form of a practical checklist. CONCLUSIONS: This White Paper is a pragmatic and flexible tool to guide the development of calibrated surveillance-based AMS interventions specific to the outpatient setting, which is characterized by substantial inter- and intra-country variability in the organization of healthcare structures, maintaining a global perspective and taking into account the feasibility of the target actions in low-resource settings.

Evidence for mutations in SARS-CoV-2 Italian isolates potentially affecting virus transmission.

Italy is the first western country suffering heavy severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission and disease impact after coronavirus disease-2019 pandemia started in China. Even though the presence of mutations on spike glycoprotein and nucleocapsid in Italian isolates has been reported, the potential impact of these mutations on viral transmission has not been evaluated. We have compared SARS-CoV-2 genome sequences from Italian patients with virus sequences from Chinese patients. We focussed upon three nonsynonymous mutations of genes coding for S(one) and N (two) viral proteins present in Italian isolates and absent in Chinese ones, using various bioinformatics tools. Amino acid analysis and changes in three-dimensional protein structure suggests the mutations reduce protein stability and, particularly for S1 mutation, the enhanced torsional ability of the molecule could favor virus binding to cell receptor(s). This theoretical interpretation awaits experimental and clinical confirmation.

Common cardiovascular risk factors and in-hospital mortality in 3,894 patients with COVID-19: survival analysis and machine learning-based findings from the multicentre Italian CORIST Study.

BACKGROUND AND AIMS: There is poor knowledge on characteristics, comorbidities and laboratory measures associated with risk for adverse outcomes and in-hospital mortality in European Countries. We aimed at identifying baseline characteristics predisposing COVID-19 patients to in-hospital death. METHODS AND RESULTS: Retrospective observational study on 3894 patients with SARS-CoV-2 infection hospitalized from February 19th to May 23rd, 2020 and recruited in 30 clinical centres distributed throughout Italy. Machine learning (random forest)-based and Cox survival analysis. 61.7% of participants were men (median age 67 years), followed up for a median of 13 days. In-hospital mortality exhibited a geographical gradient, Northern Italian regions featuring more than twofold higher death rates as compared to Central/Southern areas (15.6% vs 6.4%, respectively). Machine learning analysis revealed that the most important features in death classification were impaired renal function, elevated C reactive protein and advanced age. These findings were confirmed by multivariable Cox survival analysis (hazard ratio (HR): 8.2; 95% confidence interval (CI) 4.6-14.7 for age ≥85 vs 18-44 y); HR = 4.7; 2.9-7.7 for estimated glomerular filtration rate levels <15 vs ≥ 90 mL/min/1.73 m2; HR = 2.3; 1.5-3.6 for C-reactive protein levels ≥10 vs ≤ 3 mg/L). No relation was found with obesity, tobacco use, cardiovascular disease and related-comorbidities. The associations between these variables and mortality were substantially homogenous across all sub-groups analyses. CONCLUSIONS: Impaired renal function, elevated C-reactive protein and advanced age were major predictors of in-hospital death in a large cohort of unselected patients with COVID-19, admitted to 30 different clinical centres all over Italy.

Incidence of Bloodstream Infections, Length of Hospital Stay, and Survival in Patients With Recurrent Clostridioides difficile Infection Treated With Fecal Microbiota Transplantation or Antibiotics: A Prospective Cohort Study.

Background: Clostridioides difficile infection (CDI) is a risk factor for bloodstream infection (BSI). Fecal microbiota transplantation (FMT) is more effective than antibiotics in treating recurrent CDI, but its efficacy in preventing CDI-related BSI is uncertain. Objective: To assess incidence of primary BSI in patients with recurrent CDI treated with FMT versus antibiotics. Design: Prospective cohort study. Patients treated with FMT and those treated with antibiotics were matched on propensity score. Setting: Single academic medical center. Patients: 290 inpatients with recurrent CDI (57 patients per treatment in matched cohort). Intervention: FMT or antibiotics. Measurements: The primary outcome was primary BSI within 90 days. Secondary outcomes were length of hospitalization and overall survival (OS) at 90 days. Results: Of the 290 patients, 109 were treated with FMT and 181 received antibiotics. Five patients in the FMT group and 40 in the antibiotic group developed BSI. Because of differences in the patients treated with FMT versus antibiotics in many baseline characteristics, including number of recurrences and CDI severity, comparative analyses were limited to the matched cohort. Risk for BSI was 23 percentage points (95% CI, 10 to 35 percentage points) lower in the FMT group; the FMT group also had 14 fewer days of hospitalization (CI, 9 to 20 fewer days) and a 32-percentage point increase in OS (CI, 16 to 47 percentage points) compared with the antibiotic group. Limitation: Nonrandomized study with potential for unmeasured or residual confounding; limited generalizability of the propensity score-matched cohort. Conclusion: In a propensity score-matched cohort, patients with recurrent CDI treated with FMT were less likely to develop primary BSI. Primary Funding Source: None.

Efficacy of Ceftazidime-Avibactam Salvage Therapy in Patients With Infections Caused by Klebsiella pneumoniae Carbapenemase-producing K. pneumoniae.

Background: Ceftazidime-avibactam (CAZ-AVI) has been approved in Europe for the treatment of complicated intra-abdominal and urinary tract infections, as well as hospital-acquired pneumonia, and for gram-negative infections with limited treatment options. CAZ-AVI displays in vitro activity against Klebsiella pneumoniae carbapenemase (KPC) enzyme producers, but clinical trial data on its efficacy in this setting are lacking. Methods: We retrospectively reviewed 138 cases of infections caused by KPC-producing K. pneumoniae (KPC-Kp) in adults who received CAZ-AVI in compassionate-use programs in Italy. Case features and outcomes were analyzed, and survival was then specifically explored in the large subcohort whose infections were bacteremic. Results: The 138 patients started CAZ-AVI salvage therapy after a first-line treatment (median, 7 days) with other antimicrobials. CAZ-AVI was administered with at least 1 other active antibiotic in 109 (78.9%) cases. Thirty days after infection onset, 47 (34.1%) of the 138 patients had died. Thirty-day mortality among the 104 patients with bacteremic KPC-Kp infections was significantly lower than that of a matched cohort whose KPC-Kp bacteremia had been treated with drugs other than CAZ-AVI (36.5% vs 55.8%, P = .005). Multivariate analysis of the 208 cases of KPC-Kp bacteremia identified septic shock, neutropenia, Charlson comorbidity index ≥3, and recent mechanical ventilation as independent predictors of mortality, whereas receipt of CAZ-AVI was the sole independent predictor of survival. Conclusions: CAZ-AVI appears to be a promising drug for treatment of severe KPC-Kp infections, especially those involving bacteremia.

Liver fibrosis is associated with cognitive impairment in people living with HIV.

PURPOSE: Our aim was to better explore the association between liver fibrosis (LF) and neurocognitive impairment (NCI) in people living with HIV (PLWH). METHODS: We performed a cross-sectional cohort study by consecutively enrolling PLWH at two clinical centers. All subjects underwent a comprehensive neuropsychological battery; NCI was defined as having a pathological performance (1.5 SD below the normative mean) on at least two cognitive domains. LF was explored using FIB4 index; in a subgroup of PLWH, LF was also assessed by transient elastography. RESULTS: A total of 386 subjects were enrolled, of whom 17 (4.4%) had FIB4 > 3.25. In the subgroup of PLWH (N = 127) performing also liver transient elastography, 14 (11%) had liver stiffness > 14 kPa. Overall, 47 subjects (12%) were diagnosed with NCI. At multivariate regression analyses, participants with FIB4 > 1.45 showed a higher risk of NCI in comparison with those with lower values (aOR 3.04, p = 0.044), after adjusting for education (aOR 0.71, p < 0.001), past AIDS-defining events (aOR 2.91, p = 0.014), CD4 cell count, past injecting drug use (IDU), HIV-RNA < 50 copies/mL, and HCV co-infection. Also a liver stiffness > 14 kPa showed an independent association with a higher risk of NCI (aOR 10.13, p = 0.041). Analyzing any single cognitive domain, a higher risk of abnormal psychomotor speed was associated with a liver stiffness > 14 kPa (aOR 223.17, p = 0.019) after adjusting for education (aOR 0.57, p = 0.018), HIV-RNA < 50 copies/mL (aOR 0.01, p = 0.007), age, past IDU, and HCV co-infection. CONCLUSIONS: In PLWH, increased LF, estimated through non-invasive methods, was associated to a higher risk of NCI independently from HCV status.

Systemic inflammation markers after simplification to atazanavir/ritonavir plus lamivudine in virologically suppressed HIV-1-infected patients: ATLAS-M substudy.

Background: Biomarkers of systemic inflammation predict non-AIDS events and overall mortality in virologically suppressed HIV-1-infected patients. Objectives: To determine whether switching to a dual antiretroviral maintenance therapy was associated with modification of biomarkers of systemic inflammation as compared with continuation of successful standard triple therapy. Methods: In this substudy of the randomized ATLAS-M trial, we compared in virologically suppressed patients the impact at 1 year of simplification to a dual therapy with atazanavir/ritonavir plus lamivudine versus maintaining atazanavir/ritonavir plus two NRTI triple therapy on markers of systemic inflammation. Plasma levels of interleukin-6, C-reactive protein (CRP), soluble CD14 (sCD14) and D-dimer were quantified by ELISA at baseline and at 48 weeks. Results: A subset of 139 of 266 randomized patients with available samples was analysed: 69 in the triple therapy arm and 70 in the dual therapy arm. The baseline biomarker levels were comparable between randomization arms. No significant differences in changes from baseline to week 48 were observed between arms (dual therapy versus triple therapy): IL-6, -0.030 versus -0.016 log10 pg/L; CRP, +0.022 versus +0.027 log10 pg/mL; sCD14, -0.016 versus +0.019 log10 pg/mL; and D-dimer, -0.031 versus +0.004 log10 pg/mL. A history of cancer was associated with higher baseline levels of IL-6 (P = 0.002) and CRP (P = 0.049). No relationship was observed between baseline biomarker level and persistent residual viraemia, HIV-1 DNA load, plasma lipids and other potential explanatory variables. Conclusions: Simplification with atazanavir/ritonavir plus lamivudine does not affect plasma markers of systemic inflammation in virologically suppressed patients. The association between these findings and clinical outcomes requires further evaluation.

Atazanavir/ritonavir with lamivudine as maintenance therapy in virologically suppressed HIV-infected patients: 96 week outcomes of a randomized trial.

Objectives: To investigate the long-term safety and efficacy of a treatment switch to dual ART with atazanavir/ritonavir + lamivudine versus continuing a standard regimen with atazanavir/ritonavir + 2NRTI in virologically suppressed patients. Methods: ATLAS-M is a 96 week open-label, randomized, non-inferiority (margin -12%) trial enrolling HIV-infected adults on atazanavir/ritonavir + 2NRTI, with stable HIV-RNA <50 copies/mL and CD4 counts >200 cells/mm3. At baseline, patients were randomized 1:1 to switch to atazanavir/ritonavir + lamivudine or to continue the previous regimen. Here, we report the 96 week efficacy and safety data. The study was registered with ClinicalTrials.gov, number NCT01599364. Results: Overall, 266 subjects were enrolled (133 in each arm). At 96 weeks, in the ITT population, patients free of treatment failure totalled 103 (77.4%) with atazanavir/ritonavir + lamivudine and 87 (65.4%) with triple therapy (difference +12.0%, 95% CI +1.2/+22.8, P = 0.030), demonstrating the superiority of dual therapy. Two (1.5%) and 9 (6.8%) virological failures occurred in the dual-therapy arm and the triple-therapy arm, respectively, without development of resistance to any study drug. Clinical adverse events occurred at similar rates in both arms. A higher frequency of grade 3-4 hyperbilirubinemia (66.9% versus 50.4%, P = 0.006) and hypertriglyceridaemia (6.8% versus 1.5%, P = 0.031) occurred with dual therapy, although this never led to treatment discontinuation. A significant improvement in renal function and lumbar spine bone mineral density occurred in the dual-therapy arm. The evolution of CD4, HIV-DNA levels and neurocognitive performance was similar in both arms. Conclusions: In this randomized study, a treatment switch to atazanavir/ritonavir + lamivudine was superior over the continuation of atazanavir/ritonavir + 2NRTI in virologically suppressed patients, with a sustained benefit in terms of improved renal function and bone mineral density.

Evolution of blood-associated HIV-1 DNA levels after 48 weeks of switching to atazanavir/ritonavir+lamivudine dual therapy versus continuing triple therapy in the randomized AtLaS-M trial.

Objectives: The AtLaS-M randomized trial showed that in patients with HIV-1 RNA <50 copies/mL on atazanavir/ritonavir + two NRTIs, switching to a dual therapy with atazanavir/ritonavir+lamivudine had superior efficacy as compared with continuing the previous triple therapy. This substudy was designed to evaluate at 48 weeks the impact of the dual therapy versus the three-drug atazanavir/ritonavir-based therapy on the HIV-1 cellular reservoir as reflected by the quantification of blood-associated HIV-1 DNA levels. Methods: In a representative subset of 201 of 266 randomized patients (104 in the dual-therapy arm and 97 in the triple-therapy arm) total HIV-1 DNA levels in whole blood at baseline and after 48 weeks and factors associated with the HIV-1 DNA levels were evaluated. Results: The mean baseline HIV-1 DNA levels (2.47 log 10 copies/10 6 leucocytes) were comparable between arms. A significant mean decrease between baseline and week 48 was observed: -0.069 log 10 copies/10 6 leucocytes in the dual-therapy arm ( P = 0.046) and -0.078 in the triple-therapy arm ( P = 0.011); the mean difference between arms was -0.009 ( P = 0.842). Nadir CD4 count was inversely correlated with baseline HIV-1 DNA ( P = 0.009); longer duration of ART and lower nadir CD4 correlated with a less prominent HIV-1 DNA decrease (both P < 0.005). Higher baseline HIV-1 DNA was associated with residual viraemia at week 48 ( P = 0.031). Conclusions: When compared with continuing three-drug therapy, atazanavir/ritonavir+lamivudine dual therapy resulted in a similar decline in HIV-1 DNA levels in patients with sustained virological suppression. These data support the safety of this simplified treatment strategy in terms of its effect on the cellular HIV-1 reservoir.

Treatment simplification to atazanavir/ritonavir + lamivudine versus maintenance of atazanavir/ritonavir + two NRTIs in virologically suppressed HIV-1-infected patients: 48 week results from a randomized trial (ATLAS-M).

Background: Combination ART (cART)-related toxicities and costs have prompted the need for treatment simplification. The ATLAS-M trial explored 48 week non-inferior efficacy of simplification to atazanavir/ritonavir  +  lamivudine versus maintaining three-drug atazanavir/ritonavir-based cART in virologically suppressed patients. Methods: We performed an open-label, multicentre, randomized, non-inferiority study, enrolling HIV-infected adults on atazanavir/ritonavir + two NRTIs, with stable HIV-RNA <50 copies/mL and CD4 + >200 cells/mm 3 . Main exclusion criteria were hepatitis B virus coinfection, past virological failure on or resistance to study drugs, recent AIDS and pregnancy. Patients were randomly assigned 1:1 to either switch to 300 mg of atazanavir/100 mg of ritonavir once daily and 300 mg of lamivudine once daily (atazanavir/ritonavir + lamivudine arm) or to continue the previous regimen (atazanavir/ritonavir + two NRTIs arm). The primary study outcome was the maintenance of HIV-RNA <50 copies/mL at week 48 of the ITT-exposed (ITT-e) analysis with switch = failure. The non-inferiority margin was 12%. This study is registered at ClinicalTrials.gov, number NCT01599364. Results: Between July 2011 and June 2014, 266 patients were randomized (133 to each arm). After 48 weeks, the primary study outcome was met by 119 of 133 patients (89.5%) in the atazanavir/ritonavir + lamivudine arm and 106 of 133 patients (79.7%) in the atazanavir/ritonavir + two NRTIs arm [difference atazanavir/ritonavir + lamivudine versus atazanavir/ritonavir + two NRTIs arm: +9.8% (95% CI + 1.2 to + 18.4)], demonstrating non-inferiority and superior efficacy of the atazanavir/ritonavir + lamivudine arm. Virological failure occurred in two (1.5%) patients in the atazanavir/ritonavir + lamivudine arm and six (4.5%) patients in the atazanavir/ritonavir + two NRTIs arm, without resistance selection. A similar proportion of adverse events occurred in both arms. Conclusions: Treatment simplification to atazanavir/ritonavir + lamivudine showed non-inferior efficacy (superiority on post-hoc analysis) and a comparable safety profile over continuing atazanavir/ritonavir + two NRTIs in virologically suppressed patients.

Trimethoprim-sulfamethoxazole therapy for patients with carbapenemase-producing Klebsiella pneumoniae infections: retrospective single-center case series.

OBJECTIVE: The objective of the study was to evaluate the efficacy and tolerability of trimethoprim-sulfamethoxazole (also known as co-trimoxazole, TMPS) to treat Klebsiella pneumoniae (Kp)-K. pneumoniae carbapenemase (KPC) infections. METHODS: Clinical data of patients with a TMPS-susceptible Kp-KPC infection were collected as a case series. RESULTS: We report clinical outcomes and tolerability for 14 patients infected by Kp-KPC strains susceptible to TMPS, including three bloodstream infections. In ten cases (71.4%), TMPS was administered as monotherapy. In all but one case, Kp-KPC infection was cured. In the remaining patient, therapy was discontinued because of an adverse event. CONCLUSIONS: The use of TMPS to treat TMPS-susceptible Kp-KPC infections seems promising.