Discrepancies in fosfomycin susceptibility testing of KPC-producing Klebsiella pneumoniae with various commercial methods

Fosfomycin susceptibility testing with Sensititre, Vitek2, Etest, Mic Strip Test and disk diffusion methodologies was compared versus reference agar dilution method (AD) with 78 clinical isolates of KPC-producing Klebsiella pneumoniae. All methodologies showed a Categorical Agreement and Essential Agreement of ≤69% and ≤72%, respectively, revealing a very low concordance with AD.     

In vitro evaluation of meropenem-vaborbactam against clinical CRE isolates at a tertiary care center with low KPC-mediated carbapenem resistance

The in vitro activity of meropenem-vaborbactam was examined against clinical carbapenem-resistant Enterobacteriaceae isolates collected over 3 years at our medical center. Only 3 KPC-producers were identified. Susceptibility to meropenem-vaborbactam was noted in 15/16 (94%) isolates (MIC₉₀ 2?mg/L) that were nonsusceptible to meropenem. Meropenem-vaborbactam may have utility at centers where non–KPC-producers are more frequent.     

Surveillance Screening to Reduce Carbapenem Resistance

Carbapenem-resistant Enterobacteriaceae (CRE) have become a global public health threat due to the widespread dissemination of these highly multidrug-resistant organisms. Colonization rates are especially prevalent in long-term acute care hospitals. The optimal approach for active surveillance screening to decrease CRE transmission is frequently lacking in health care facilities. The economic burden of this resistant organism is speculated to escalate with increasing prevalence. Billions of health care dollars and high mortality rates are attributed to this virulent superbug with limited treatment options, thus lending to the importance of prevention and control of CRE.     

Hepatotoxicity of tubers of Indian Kudzu (Pueraria tuberosa) in rats

Methanolic extract of tubers of Pueraria tuberosa Linn. (Fabaceae) (PTME) has been tested for hepatoxicity in rats. In acute study, PTME (100–400 mg/100 g BW, given orally) showed LD₅₀ at 227.5 mg. For sub-chronic study, its repeated doses (5–100 mg/100 g BW, for 30 days), significantly increased hepatic enzymes in blood, sinusoidal congestion, disruption of central vein, inflammatory cell infiltration and hepatocellular necrosis in liver in dose dependent manner, with increase in NO, iNOS and ROS levels. In a kinetic study (single dose 227.5 mg/100 g BW), there was sequential decrease in GSH and enhanced NO suggesting free-radical generation as the primary cause of cell damage. It is concluded that the higher dosing of PTME or its continuous use for longer period (even in low doses) is hepatotoxicity by inducing oxidative stress.     

In vivo study assessed meropenem and amikacin combination therapy against carbapenem-resistant and carbapenemase-producing Enterobacteriaceae strains

BackgroundCarbapenem-resistant Enterobacteriaceae (CRE), especially for carbapenemase-producing Enterobacteriaceae (CPE), is an emerging cause that pose a significant threat to public health. However, efficient therapy has not been established. We assessed the antimicrobial efficacy of meropenem (MEPM) and amikacin (AMK) combination therapy.Material and methodsTotal eight isolates of Escherichia coli or Klebsiella pneumoniae, including CRE and/or CPE have carbapenemase genes were used. The relationship between phenotype and in vivo efficacy was assessed in neutropenic murine thigh infection model. Efficacy was determined using the change in bacterial density and survival rate.ResultsThe combination therapy showed enhanced antimicrobial activities against CRE+/CPE+ and CRE+/CPE-K. pneumoniae isolates than MEPM monotherapy (0.63 ± 0.04 vs. 2.56 ± 0.24 ⊿log₁₀ cfu/mL, p < 0.05; −1.05 ± 0.15 vs. −0.48 ± 0.30 ⊿log₁₀ cfu/mL, p < 0.05). Likewise, the combination therapy showed enhanced antimicrobial activities against CRE+/CPE+ and CRE+/CPE-E. coli isolates than MEPM monotherapy (0.90 ± 0.68 vs. 1.86 ± 0.23 ⊿log₁₀ cfu/mL, p < 0.05; −1.81 ± 0.06 vs. −0.88 ± 0.23 ⊿log₁₀ cfu/mL, p < 0.05). Also, combination therapy group showed similar to higher survival rates in CRE + E. coli infection mice, compared to MEPM monotherapy group.ConclusionOur results are the first supportive data to threat CRE infections with combination therapy of MEPM and AMK with in vivo model. The current results verify the promising utility of the combination therapy with MEPM and AMK against CRE isolates with a wide range of MEPM MICs.     

Characteristics and Clinical Implications of Carbapenemase-Producing Klebsiella pneumoniae Colonization and Infection,Italy

Klebsiella pneumoniae carbapenemase–producing K. pneumoniae (KPC-Kp) has been endemic in Italy since 2013. In a multicenter cohort study, we investigated various aspects of KPC-Kp among patients, including 15-day mortality rates and delays in adequate therapy. Most (77%) KPC-Kp strains were sequence type (ST) ST512 or ST307. During 2017, KPC-Kp prevalence was 3.26 cases/1,000 hospitalized patients. Cumulative incidence of KPC-Kp acquired >48 hours after hospital admission was 0.68% but varied widely between centers. Among patients with mild infections and noninfected colonized patients, 15-day mortality rates were comparable, but rates were much higher among patients with severe infections. Delays of >4 days in receiving adequate therapy more frequently occurred among patients with mild infections than those with severe infections, and delays were less common for patients with known previous KPC-Kp colonization. Italy urgently needs a concerted surveillance system to control the spread of KPC-Kp.