Treatment of long-term catheter-related bloodstream infections with short-course Daptomycin lock and systemic therapy associated with Taurolidine-lock: A multicenter experience

PURPOSE

Few studies describe the efficacy of antibiotic lock therapy (ALT) in long-term catheter-related bloodstream (CRBSI) infections. We applied local protocols combining Daptomycin (DPT) and Taurolidine ALT, associated with systemic antibiotic treatment (SAT), for conservative management of coagulase-negative Staphylococci (CoNS) CRBSI.

METHODS

Patients admitted for CoNS-associated CRBSI and treated with DPT and Taurolidine as ALT were retrospectively analyzed. Success was defined as catheter retention 30 days after ending treatment. Catheter removal within 30 days was considered as failure.

RESULTS

From April 2018 to September 2021, 22 subjects with CoNS-associated-CRBSI were included (95% with cancer, mean age 64 years, 59% male). Staphylococcus epidermidis was isolated in 82% of cases. Mean duration of DPT was 3.9 and 3 days as ALT and SAT, respectively. SAT also included Rifampin for 3 days. Taurolidine ALT was started on day 4 and was combined with oral SAT, that is, either Linezolid or Tedizolid. Mean duration of Taurolidine was 10.5 days, while total antibiotic treatment lasted 13.5 days. Clinical success and failure rates were 95% and 5%, respectively.

DISCUSSION

Short course DPT as ALT, combined with SAT and Taurolidine ALT, allowed high rates of conservative management of catheters in case of CoNS-associated-CRBSI.

Immune response to BNT162b2 SARS-CoV-2 vaccine in patients living with HIV: The COVIH-DAPT study

Introduction

Data on immune response to SARS-CoV-2 vaccine in patients living with HIV (PLWH) over a period longer than 3 months are currently limited. We measured the immune response after BNT162b2 vaccination against SARS-CoV-2 in this population.

Methods

We prospectively enrolled PLWH on successful antiretroviral therapy, initiating vaccination with two doses of the BNT162b2 SARS-CoV-2 vaccine administered at six-week interval. SARS-CoV-2 humoral and cellular responses and lymphocyte cell subsets were recorded at inclusion and 6 weeks (W6), 3 months (M3) and 6 months (M6) later. Humoral, humoral strong and cellular responders were defined by IgG titers >10, ≥264BAU/mL and IFN-γ T cell release, respectively.

Results

Nineteen subjects without SARS-CoV-2 infection were included (74% men, mean age 51 years, CD4 nadir 399/mm3). All subjects were humoral responders, their antibody titer peak reached at M3. Strong responders' rates were 63% and 21% at M3 and M6, respectively. CD19+CD10+ B cells had increased significantly at W6 then decreased at M3, while CD19+CD27+ B cells remained unchanged. Rates of patients with a cellular response increased from 39% at W6 to 69% at M6. Cellular responders had significantly higher CD3+, CD4+ and CD8+ Effector Memory cells at inclusion (p=0.048, p=0.024, p=0.012, respectively) and CD4+ Terminally Differentiated Effector Memory cells at M3 (p=0.044).

Discussion

PLWH have a robust immune response after SARS-CoV-2 vaccination, but a rapid decline in humoral response from 3 months onwards, due to a blunted memory B cell response. Analysis of lymphocyte subsets may help identify optimal times for vaccine boosters.

Prevalence and Main Clinical Characteristics of Fully Vaccinated Patients Admitted to Hospital for Delta Variant COVID-19

Objectives

The Delta variant of the novel beta coronavirus responsible for the current coronavirus pandemic (COVID-19) spread across Europe during the summer of 2021. Little is known of vaccine efficacy on this variant. Our aim was to study the prevalence and clinical characteristics of fully vaccinated subjects admitted to hospital for Delta variant COVID-19.

Methods

We identified patients admitted to Cannes hospital for Delta-variant-related Covid-19 infection from July to September 2021. Their main demographic parameters, inflammatory markers, and clinical characteristics were recorded. Differences between fully vaccinated subjects and unvaccinated or incompletely vaccinated individuals were analyzed.

Results

We included 126 patients (57% male, mean age 64 years, mean delay since symptoms onset 7.8 days). Among admitted patients, 94 (75%) were not vaccinated, 11 (8%) incompletely so and 21 (17%) were fully vaccinated. Fully vaccinated patients were older (77 vs. 61 vs. 62 years, p = 0.003), with fewer days since symptoms onset (5.9 vs. 8.0 vs. 9.3 days, p = 0.035) than unvaccinated or incompletely vaccinated patients, respectively. Severe pneumonia was less frequent among completely vaccinated subjects (67 vs. 84 vs. 100%, p = 0.038), while rates of transfer to the ICU, mechanical ventilation or death did not differ. Thirteen fully vaccinated patients underwent a thoracic CT scan, revealing involvement of lung parenchyma in four of them.

Discussion

Prevalence of hospitalization for Delta-variant COVID-19 in fully vaccinated subjects was low and, despite their age and comorbid conditions, these patients had a high rate of favorable outcome.

Switching to a Dual-Drug Regimen in HIV-Infected Patients Could Be Associated With Macrophage Activation?

Objectives: The aim of this study was to evaluate the effect on immune activation of switching from a triple-drug to a dual-drug regimen in HIV-1 infected patients on successful combination antiretroviral treatment (cART). Immunadapt is a prospective study evaluating the impact of cART simplification on immune activation.

Methods: We prospectively collected blood samples in HIV-1 infected patients on stable and successful cART switching from triple to dual regimens as a simplifying strategy. We compared immune activation markers: high sensitivity CRP, IL-1, IL-6, IL-8, IP-10, MCP-1, TNF-alpha, soluble CD14 (sCD14), soluble CD163 (sCD163), lipopolysaccharide binding protein, and D-dimer before cART change and at least 6 months after the switch. Patients were stratified according to low or high risk factors of immune activation (low CD4 nadir, previous AIDS-defining condition or very-low-level viremia during follow-up).

Results: From April 2019 to May 2020, 20 subjects were included (mean age 57 years, 25 years since HIV infection, CD4 666 cells/mm3, CD8 766 cells/mm3, CD4/CD8 0.94, CD4 nadir 326 cells/mm3, 15% with AIDS, 18 years on cART, 6 cART regimens received, current cART duration: 56 months). Fourteen patients were prescribed Dolutegravir + Rilpivirine and six received Dolutegravir + Lamivudine. After 6.9 months, a significant sCD163 increase (+ 25.5% vs. + 0.5%, p = 0.02) was observed in subjects with high risk factors, despite maintaining a viral load <50 cp/ml.

Conclusion: cART simplification in favor of dual therapy is associated with macrophage activation in patients at risk of immune activation despite sustained virological control. Risk factors should thus be considered before generalizing such strategies.

Patients with Covid-19 exhibit different immunological profiles according to their clinical presentation

OBJECTIVES

A novel beta coronavirus has been identified as responsible for the 2019 coronavirus infection (Covid-19). Clinical presentations range from asymptomatic cases to acute respiratory distress syndrome with fatal outcome. Such a broad spectrum of disease expression calls for an investigation of immune response characteristics.

METHODS

We identified subjects admitted for Covid-19 in whom a large panel of immunological markers were measured, including B- and T- and NK-lymphocyte phenotypes, T-lymphocyte subpopulation cells and plasma cytokines. Patients were divided according to symptom severity during hospitalisation, in those with uncomplicated and complicated infection. Differences between groups were analyzed.

RESULTS

Seventeen patients were included (mean age: 83 years; 9 women; mean delay of symptoms onset: 4 days). Six had uncomplicated infection, while 11 developed complicated forms during hospitalization. CD10 + B lymphocyte levels were inversely correlated with clinical severity (5.8% vs 2.0%, p = 0.04) and CD10+ levels above 3% were independently associated with uncomplicated forms [Odds Ratio 0.04 (CI 0.002-0.795, p = 0.034)]. TNF-alpha, IL-1, Il-6 and Il-8 measurements upon admission differed between patients who died and those who survived (p < 0.01 for all comparisons).

CONCLUSIONS

In a population of elderly patients recently infected with Covid-19, CD10 + B cell levels were inversely correlated with clinical severity. Cytokine values upon admission were highly predictive of fatal outcome during hospitalisation. These findings could explain differences in the clinical presentation and allow rapid identification of patients at risk for complications.

Actinotignum schaalii (formerly Actinobaculum schaalii): a newly recognized pathogen-review of the literature

The genus Actinotignum contains three species, Actinotignum schaalii (formerly Actinobaculum schaalii), Actinotignum urinale and Actinotignum sanguinis. A. schaalii is the species most frequently involved in human infections, with 172 cases, mostly urinary tract infections (UTIs), reported so far. Invasive infections have also been described. This facultative anaerobic Gram-positive rod is part of the urinary microbiota of healthy patients. It is responsible for UTIs, particularly in elderly men and young children. A. schaalii is an underestimated cause of UTIs because of its fastidious growth on usual media and difficulties associated with its identification using phenotypic methods. Indeed, this slow-growth bacterium requires blood-enriched media and an incubation time of 48 hours under anaerobic or 5% CO2 atmosphere. Furthermore, only matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF) or molecular-based methods allow the accurate identification of this bacteria. MALDI-TOF using Microflex LT with the Biotyper database (Bruker Daltonics, Bremen, Germany) is the most reliable technology for the routine identification of A. schaalii. The identification of this uropathogen is all the more important because it is resistant to trimethoprim/sulfamethoxazole and second-generation quinolones that are widely used in the treatment of UTIs. Antimicrobial therapy using β-lactams prolonged for up to 2 weeks is the most efficient treatment and should be recommended. Microbiologists should assess the presence of A. schaalii in urine using appropriate culture and identification methods in the case of a direct examination that is positive for small coccoid rods, a negative nitrite urinary stick associated with leukocyturia, treatment failure with trimethoprim/sulfamethoxazole or fluoroquinolones, or undocumented, repeated UTIs.