Colonization by ceftazidime/avibactam-resistant KPC-producing Klebsiella pneumoniae following therapy in critically ill patients.

OBJECTIVES: Ceftazidime-avibactam (CAZ-AVI)-based treatments have been associated with the emergence of resistance in KPC-producing Klebsiella pneumoniae (KPC-Kp) isolates after antimicrobial exposure. Here, we evaluated the CAZ-AVI resistance development in KPC-Kp isolated from patients treated with CAZ-AVI-based therapy. METHODS: We enrolled adult patients treated with CAZ-AVI-based regimens between January 2020 and January 2021. Carbapenemase-producing isolates collected from clinical samples and rectal swabs were evaluated for CAZ-AVI resistance development after antimicrobial exposure. KPC-Kp developing CAZ-AVI resistance and parental susceptible strains were genomically characterized. Whole genome sequencing was performed by using the Illumina iSeq100 platform and genomes were analyzed for antimicrobial-resistance genes, plasmid and porins sequences. RESULTS: We enrolled 90 patients treated with CAZ-AVI-based therapy and 62.2% (56/90) of them were colonized by KPC-producers before CAZ-AVI-based treatment and 6.6% acquired colonization during therapy. Six (6.6%) patients developed infections because of resistant KPC-Kp after CAZ-AVI exposure and 3 (3.3%) of them developed CAZ-AVI resistance in the rectum. Development of resistance among KPC in the rectum occurred after 32 (IQR, 9-35) days of therapy and after 30 (IQR, 22-40) days in clinical specimens. Genetic analysis demonstrated that the development of CAZ-AVI resistance was associated with mutated blaKPC-3 (blaKPC-31, blaKPC-53, blaKPC-89, and blaKPC-130) and phylogenetic analysis demonstrated a close genomic relationship between KCP-Kp collected from rectum and clinical samples of the same patient. DISCUSSION: Antimicrobial exposure induce a higher incidence of CAZ-AVI resistance development in the blood and respiratory tract than in the rectum (6.7% vs. 3.3%) of CAZ-AVI-treated patients and genome analysis showed that resistance was associated with mutated blaKPC-3 variants.

Use of meropenem in treating carbapenem-resistant Enterobacteriaceae infections.

Introduction: The epidemiology of carbapenem-resistant Enterobacterales (CRE) is increasingly worldwide. Production of carbapenemases is the most common and efficient mechanism of carbapenem resistance, and could theoretically be overcome by optimizing the pharmacokinetic/pharmacodynamic (PK/PD) behavior of meropenem. Areas covered: This article overviews the available literature concerning the potential role that meropenem may still have in the treatment carbapenem-resistant Enterobacteriaceae infections. Clinical studies published in English language until June 2019 were searched on PubMed database. Expert commentary: High-dose continuous infusion meropenem-based combination regimens could still represent a valuable option for treating CRE infections in specific circumstances. Knowledge of the local prevalent mechanisms of carbapenem resistance, of patient clinical severity, of the site of infection, of an accurate minimum inhibitory concentration (MIC) value, coupled with the possibility of carrying-out a real-time therapeutic drug monitoring (TDM)-based PK/PD optimization of drug exposure must all be considered as fundamental for properly pursuing this goal.

The role of extended infusion ß-lactams in the treatment of bloodstream infections in patients with liver cirrhosis.

INTRODUCTION: Bloodstream infections (BSIs) in patients with liver cirrhosis are associated with significant morbidity and mortality. Early appropriated antibiotic treatment is essential for the correct management of these patients. Areas covered: This review covers several aspects of how the pharmacokinetic/pharmacodynamic behavior of antimicrobials may change in patients with liver cirrhosis. Common features of cirrhosis, including hypoproteinemia, third space expansion and impairment of renal function may alter drug distribution in patients receiving hydrophilic drugs like ß-lactams, which are often frontline agents. ß-lactams exhibit time-dependent pharmacodynamics and achieve maximal bacterial killing when serum drug and tissue concentrations exceed a multiple of the minimal inhibitory concentration (MIC) during the dosing interval (%fT>MIC). Administration of ß-lactams by extended infusion strategies improves the rate of this pharmacodynamic target attainment and has been associated with improved outcomes in several randomized trials in critically-ill patients. Expert commentary: Observational studies have suggested that cirrhotic patients have improved outcomes when beta-lactam therapy is administered by extended or continuum infusion. Given the multiple pathophysiological features of liver cirrhosis that impact antimicrobial behavior and the high incidence of multidrug resistance in this population, additional studies are needed to understand how cirrhosis affects the pharmacokinetics and pharmacodynamics of antibacterial therapy.

Use and perception of complementary and alternative medicine among cancer patients: the CAMEO-PRO study : Complementary and alternative medicine in oncology.

BACKGROUND: It is estimated that about half of cancer patients use at least one form of complementary and alternative medicines (CAM) in their life but there is a strong reticence of patients in talking about CAM with their oncologist. Primary aim of this study was to inform patients about CAM, focusing on their supposed benefits, toxicities and interactions with conventional therapeutic agents. The study also explored patients' perception about CAM and ascertained the level of CAM use among cancer patients of an Italian academic hospital. METHODS: From April 2016 to April 2017, the observational pilot trial "CAMEO-PRO" prospectively enrolled 239 cancer patients that were invited to attend a tutorial about CAM at the Department of oncology, University Hospital of Udine, Italy. Before and after the informative session, patients were asked to fill a questionnaire reporting their knowledge and opinion about CAM. RESULTS: Overall, 163 (70%) women and 70 (30%) men were enrolled. Median age was 61 years. At study entry, 168 (72%) patients declared they had never been interested in this topic previously; 24 patients (11%) revealed the use of a type of alternative therapy and 58 (28%) revealed the use of complementary therapy. In total, 139 (55.2%) patients attended the informative session. Bowker's test of symmetry demonstrated statistically significant opinion's change after the session on 9 out of 14 explored items. CONCLUSIONS: Informative sessions seem to have a relevant impact on patients' perceptions and opinions about CAM.

In vivo evolution of resistant subpopulations of KPC-producing Klebsiella pneumoniae during ceftazidime/avibactam treatment.

Objectives: KPC-producing Klebsiella pneumoniae (KPC-Kp) represent a serious problem worldwide. Herein, we describe the evolution of ceftazidime/avibactam resistance by sequencing longitudinal clinical isolates from a patient with KPC-Kp bloodstream infection undergoing ceftazidime/avibactam treatment. Methods: WGS was performed on one ceftazidime/avibactam-susceptible KPC-Kp (BOT-CA-S) and two phenotypically different ceftazidime/avibactam-resistant KPC-Kp with low (BOT-CA-R) and high (BOT-EMO) carbapenem MICs. The population diversity was assessed by the frequency of allele mutations and population analysis profiles (PAPs). Results: Phylogenetic analysis demonstrated clonal relatedness of the KPC-Kp isolates, all belonging to the clone ST1519. The D179Y mutation in blaKPC-3 was detected in both of the ceftazidime/avibactam-resistant KPC-Kp, whereas it was absent in the ceftazidime/avibactam-susceptible isolate. The mutation emerged independently in the two ceftazidime/avibactam-resistant isolates and was associated with a significant reduction in carbapenem MICs in BOT-CA-R, but not in BOT-EMO. WGS analysis revealed that the frequency of the D179Y mutation was 96.32% and 51.05% in BOT-CA-R and BOT-EMO, respectively. PAP results demonstrated that carbapenem resistance in BOT-EMO was due to the coexistence of mixed subpopulations harbouring WT and mutated blaKPC-3. A bacterial subpopulation with high ceftazidime/avibactam resistance for BOT-EMO KPC-Kp showed low carbapenem MICs, whereas a subpopulation with high meropenem resistance had a low MIC of ceftazidime/avibactam. Conclusions: Our analysis indicates that mixed subpopulations of ceftazidime/avibactam-resistant KPC-Kp emerge after ceftazidime/avibactam treatment. The evolution of different subpopulations that are highly resistant to ceftazidime/avibactam likely contributes to treatment failure, thereby highlighting the need for combination treatment strategies to limit selection of ceftazidime/avibactam-resistant KPC-Kp subpopulations.

Liver transplantation is associated with good clinical outcome in patients with active tuberculosis and acute liver failure due to anti-tubercular treatment.

BACKGROUND: Active tuberculosis (TB) is commonly considered a contraindication for liver transplantation (LT). However, in patients with TB who develop acute liver failure (ALF) due to toxicity induced by anti-tubercular treatment (ATT), LT could be the only opportunity for treatment. The aim of this study was to evaluate the feasibility of LT in this scenario. METHODS: We described 2 cases and comprehensively reviewed the literature finding 26 cases of LT performed in patients having a concomitant active TB and liver failure secondary to ATT toxicity. RESULTS: TB was classified as pulmonary in 18/26 (69%), nodal in 3/26 (11%) TB cases, while the remaining 5/26 cases included disseminated, pleural, renal, ovarian, and vertebral TB localization (1 case each). ATT following LT consisted mainly of isoniazid or rifampin (RIF)-sparing regimens and included primarily fluoroquinolones and ethambutol. Rejection episodes and liver toxicity were reported in 19% and 8% of patients respectively. Graft rejection was more frequent among patients treated with RIF-containing regimens (P<.001). Mortality rate was 15% after a median follow up of 12 months. In only one case was death attributed to uncontrolled TB infection. CONCLUSION: Our findings suggest that LT is an effective therapeutic option for patients with active TB developing ALF following ATT and should be considered for patients failing medical treatment.

Infections caused by KPC-producing Klebsiella pneumoniae: differences in therapy and mortality in a multicentre study.

OBJECTIVES: Infections caused by Klebsiella pneumoniae (Kp) carbapenemase (KPC)-producing strains of Kp have become a significant threat in recent years. To assess their outcomes and identify risk factors for 14 day mortality, we conducted a 4 year (2010-13) retrospective cohort study in five large Italian teaching hospitals. METHODS: The cohort included 661 adults with bloodstream infections (BSIs; n = 447) or non-bacteraemic infections (lower respiratory tract, intra-abdominal structure, urinary tract or other sites) caused by a KPC-Kp isolate. All had received ≥48 h of therapy (empirical and/or non-empirical) with at least one drug to which the isolate was susceptible. RESULTS: Most deaths occurred within 2 weeks of infection onset (14 day mortality: 225/661, 34.1%). Logistic regression analysis identified BSI (OR, 2.09; 95% CI, 1.34-3.29), presentation with septic shock (OR, 2.45; 95% CI, 1.47-4.08), inadequate empirical antimicrobial therapy (OR, 1.48; 95% CI, 1.01-2.18), chronic renal failure (OR, 2.27; 95% CI, 1.44-3.58), high APACHE III score (OR, 1.05; 95% CI, 1.04-1.07) and colistin-resistant isolates (OR, 2.18; 95% CI, 1.37-3.46) as independent predictors of 14 day mortality. Combination therapy with at least two drugs displaying in vitro activity against the isolate was associated with lower mortality (OR, 0.52; 95% CI, 0.35-0.77), in particular in patients with BSIs, lung infections or high APACHE III scores and/or septic shock at infection onset. Combinations that included meropenem were associated with significantly higher survival rates when the KPC-Kp isolate had a meropenem MIC of ≤8 mg/L. CONCLUSIONS: KPC-Kp infections are associated with high mortality. Treatment with two or more drugs displaying activity against the isolate improves survival, mainly in patients who are critically ill.