In vitro and in vivo synergistic effects of tigecycline combined with aminoglycosides on carbapenem-resistant Klebsiella pneumoniae

2021 ◽  
Author(s):  
Wentao Ni ◽  
Deqing Yang ◽  
Jie Guan ◽  
Wen Xi ◽  
Dexun Zhou ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Synergistic Effects ◽  
Molecular Characteristics ◽  
Synergistic Activity ◽  
Significant Activity ◽  
Clinical Pharmacokinetics ◽  
Carbapenem Resistant ◽  
Time Kill

Abstract Objectives Carbapenem-resistant Klebsiella pneumoniae (CR-KP) infections represent severe threats to public health worldwide. The aim of this study was to assess potential synergistic interaction between tigecycline and aminoglycosides via in vitro and in vivo studies. Methods Antibiotic resistance profiles and molecular characteristics of 168 CR-KP clinical isolates were investigated by susceptibility testing, PCR and MLST. Chequerboard tests and time–kill assays were performed for 20 CR-KP isolates to evaluate in vitro synergistic effects of tigecycline combined with aminoglycosides. A tissue-cage infection model of rats was established to evaluate in vivo synergistic effects. Different doses of tigecycline and aminoglycosides alone or in combination were administered for 7 days via tail vein injection. Antibiotic efficacy was evaluated in tissue-cage fluid and emergence of resistance was screened. Results The chequerboard tests showed that this combination displayed synergistic or partial synergistic activity against CR-KP. The time–kill assays further demonstrated that strong synergistic effects of such a combination existed against isolates that were susceptible to both drugs but for resistant isolates no synergy was observed if clinical pharmacokinetics were taken into consideration. The in vivo study showed that the therapeutic effectiveness of combination therapies was better than that of monotherapy for susceptible isolates, suggesting in vivo synergistic effects. Furthermore, combinations of tigecycline with an aminoglycoside showed significant activity in reducing the occurrence of tigecycline-resistant mutants. Conclusions Compared with single drugs, tigecycline combined with aminoglycosides could exert synergistic effects and reduce the emergence of tigecycline resistance. Such a combination might be an effective alternative when treating CR-KP infections in clinical practice.

scholarly journals Comparative analysis of Clinial Carbapenem- Resistant (CR), Hypermucoviscous (HM) and CR-HM Klebsiella pneumoniae isolates in China

2020 ◽  
Author(s):  
Jun-Ying Zhu ◽  
Guang-Yu Wang ◽  
Qing Wei ◽  
Zhen Shen ◽  
Qiong Li ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Virulence Genes ◽  
Carbapenem Resistance ◽  
Resistance Rate ◽  
Molecular Characteristics ◽  
Carbapenem Resistant ◽  
Recent Emergence ◽  
String Test

Abstract Background: Although carbapenem-resistant Klebsiella pneumoniae (CRKP) and hypermucoviscous K. pneumoniae (HMKP) were largely non-overlapping, the recent emergence of CR-HMKP has raised great alarm in the world. We compared the molecular characteristics of CRKP, HMKP and CR-HMKP isolates.Results: 220 cases of K. pneumoniae isolates was collected and identified between Jan 2015 and Dec 2016 from Renji Hospital. Carbapenem resistance test and string test were performed to screen CRKP, HMKP and CR-HMKP isolates. All the CRKP, HMKP and CR-HMKP isolates were investigated for capsular genotyping, virulence genes and resistance genes by PCR and DNA sequencing. Multilocus sequence typing (MLST) was used to characterize isolates sequence types (STs). Serum killing assay and mouse lethality assay were respectively performed to confirm the virulence of the isolates in vitro and in vivo. Of 220 K. pneumoniae，71 HMKP, 84 CRKP and 8 CR-HMKP were identified. Resistance rate to carbapenems was significantly higher in CRKP than HMKP and CR-HMKP. For MLST and serotyping, ST23 (26.8%)，K1 (33.8%) and K2 (23.9%) serotypes were the most common in HMKP isolates while ST11 (84.5%, 100%) and K-nontypable (91.6%, 100%) were the predominant types in CRKP and CR-HMKP isolates. The existence of virulence genes rmpA, magA and iutA was significantly higher in HMKP while the prevalence of resistance gene blaKPC-2 was higher in CRKP and CR-HMKP. Virulence test in vivo and in vitro both showed the lower virulence of CRKP and CR-HMKP compared to HMKP.Conclusions: In spite of low virulence, the emergence of CR-HMKP indicates a confluence of hypermucoviscous phenotype and carbapenem resistance. Furthermore, the similar molecular characteristics between CRKP and CR-HMKP suggested that CR-HMKP might evolve from CRKP.

scholarly journals Synergistic activity of fosfomycin–meropenem and fosfomycin–colistin against carbapenem resistant Klebsiella pneumoniae: an in vitro evidence

2020 ◽  
pp. FSO461 ◽  
Author(s):  
Yamuna Devi Bakthavatchalam ◽  
Abirami Shankar ◽  
Dhiviya Prabaa Muthuirulandi Sethuvel ◽  
Kalaiarasi Asokan ◽  
Kalaiarasi Kanthan ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Klebsiella Pneumoniae ◽  
Blood Cultures ◽  
Synergistic Activity ◽  
Carbapenem Resistant ◽  
Resistant Genes ◽  
Time Kill ◽  
Synergistic Antibacterial Activity

Aim: To evaluate the antibacterial activity of fosfomycin–meropenem and fosfomycin–colistin combinations against carbapenem-resistant Klebsiella pneumoniae (CR-Kp). Methods: A total of 50 CR-Kp isolates recovered from blood cultures were included in this study. All the CR-Kp isolates were screened for the presence of carbapenem resistant genes blaIMP. blaVIM. blaNDM. blaOXA-48 like, blaKPC. blaGES.#x00A0;and blaSPM. Combination testing of fosfomycin–meropenem and fosfomycin–colistin were performed using time-kill assay. Results: Fosfomycin–meropenem combination showed synergy in 20% of the tested CR-Kp isolates. While, fosfomycin–colistin exhibited synergy against 16% of the isolates. A total of 68% (n = 34) of CR-Kp isolates were characterised as OXA-48-like producers and 22% (n = 11) as NDM producers. Synergistic activity of these combinations was observed against OXA-48, NDM and NDM + OXA-48 co-producers. Conclusion: Considerable synergistic antibacterial activity of fosfomycin–meropenem and fosfomycin–colistin was not observed against CR-Kp isolates. Therefore, these combinations may not be promising for infections associated with CR-Kp.

scholarly journals Combination of Colistin and Azidothymidine Demonstrates Synergistic Activity against Colistin-Resistant, Carbapenem-Resistant Klebsiella pneumoniae

2020 ◽  
Vol 8 (12) ◽  
pp. 1964
Author(s):  
Ya-Ting Chang ◽  
Tsung-Ying Yang ◽  
Po-Liang Lu ◽  
Shang-Yi Lin ◽  
Liang-Chun Wang ◽  
...  
Keyword(s):  
Combination Therapy ◽  
Klebsiella Pneumoniae ◽  
Therapeutic Option ◽  
Rapid Evolution ◽  
Toxicity Testing ◽  
World Health ◽  
Synergistic Activity ◽  
Carbapenem Resistant

Carbapenem-resistant Enterobacteriaceae (CRE) is listed as an urgent threat by the World Health Organization because of the limited therapeutic options, rapid evolution of resistance mechanisms, and worldwide dissemination. Colistin is a common backbone agent among the “last-resort” antibiotics for CRE; however, its emerging resistance among CRE has taken the present dilemma to the next level. Azidothymidine (AZT), a thymidine analog used to treat human immunodeficiency virus/acquired immunodeficiency syndrome, has been known to possess antibacterial effects against Enterobacteriaceae. In this study, we investigated the combined effects of AZT and colistin in 40 clinical isolates of colistin-resistant, carbapenem-resistant K. pneumoniae (CCRKP). Eleven of the 40 isolates harbored Klebsiella pneumoniae carbapenemase. The in vitro checkerboard method and in vivo nematode killing assay both revealed synergistic activity between the two agents, with fractional inhibitory concentration indexes of ≤0.5 in every strain. Additionally, a significantly lower hazard ratio was observed for the nematodes treated with combination therapy (0.288; p < 0.0001) compared with either AZT or colistin treatment. Toxicity testing indicated potentially low toxicity of the combination therapy. Thus, the AZT–colistin combination could be a potentially favorable therapeutic option for treating CCRKP.

Emergence of ceftazidime/avibactam resistance in KPC-3-producing Klebsiella pneumoniae in vivo

2019 ◽  
Vol 74 (11) ◽  
pp. 3211-3216 ◽  
Author(s):  
Stephan Göttig ◽  
Denia Frank ◽  
Eleonora Mungo ◽  
Anika Nolte ◽  
Michael Hogardt ◽  
...  
Keyword(s):  
Combination Therapy ◽  
Klebsiella Pneumoniae ◽  
Selection Pressure ◽  
Galleria Mellonella ◽  
Phenotypic Characterization ◽  
Infection Model ◽  
Development Of Resistance ◽  
Time Kill

Abstract Objectives The β-lactam/β-lactamase inhibitor combination ceftazidime/avibactam is active against KPC-producing Enterobacterales. Herein, we present molecular and phenotypic characterization of ceftazidime/avibactam resistance in KPC-3-producing Klebsiella pneumoniae that emerged in vivo and in vitro. Methods Sequence analysis of blaKPC-3 was performed from clinical and in vitro-generated ceftazidime/avibactam-resistant K. pneumoniae isolates. Time–kill kinetics and the Galleria mellonella infection model were applied to evaluate the activity of ceftazidime/avibactam and imipenem alone and in combination. Results The ceftazidime/avibactam-resistant clinical K. pneumoniae isolate revealed the amino acid change D179Y in KPC-3. Sixteen novel mutational changes in KPC-3 among in vitro-selected ceftazidime/avibactam-resistant isolates were described. Time–kill kinetics showed the emergence of a resistant subpopulation under selection pressure with either imipenem or ceftazidime/avibactam. However, combined selection pressure with imipenem plus ceftazidime/avibactam prevented the development of resistance and resulted in bactericidal activity. Concordantly, the G. mellonella infection model revealed that monotherapy with ceftazidime/avibactam is prone to select for resistance in vivo and that combination therapy with imipenem results in significantly better survival. Conclusions Ceftazidime/avibactam is a valuable antibiotic against MDR and carbapenem-resistant Enterobacterales. Based on time–kill kinetics as well as an in vivo infection model we postulate a combination therapy of ceftazidime/avibactam and imipenem as a strategy to prevent the development of ceftazidime/avibactam resistance in KPC-producing Enterobacterales in vivo.

scholarly journals Semimechanistic Pharmacokinetic/Pharmacodynamic Modeling of Fosfomycin and Sulbactam Combination against Carbapenem-Resistant Acinetobacter baumannii

2021 ◽  
Vol 65 (5) ◽  
Author(s):  
Sazlyna Mohd Sazlly Lim ◽  
Aaron J. Heffernan ◽  
Jason A. Roberts ◽  
Fekade B. Sime
Keyword(s):  
Acinetobacter Baumannii ◽  
Treatment Options ◽  
Pharmacodynamic Modeling ◽  
Synergistic Activity ◽  
Bacterial Burden ◽  
Target Attainment ◽  
Content Type ◽  
Carbapenem Resistant ◽  
Time Kill

ABSTRACT Due to limited treatment options for carbapenem-resistant Acinetobacter baumannii (CR-AB) infections, antibiotic combinations are now considered potential treatments for CR-AB. This study aimed to explore the utility of fosfomycin-sulbactam combination (FOS/SUL) therapy against CR-AB isolates. Synergism of FOS/SUL against 50 clinical CR-AB isolates was screened using the checkerboard method. Thereafter, time-kill studies against two CR-AB isolates were performed. The time-kill data were described using a semimechanistic pharmacokinetic/pharmacodynamic (PK/PD) model. Monte Carlo simulations were then performed to estimate the probability of stasis, 1-log kill, and 2-log kill after 24 h of combination therapy. The FOS/SUL combination demonstrated a synergistic effect against 74% of isolates. No antagonism was observed. The MIC50 and MIC90 of FOS/SUL were decreased 4- to 8-fold, compared to the monotherapy MIC50 and MIC90. In the time-kill studies, the combination displayed bactericidal activity against both isolates and synergistic activity against one isolate at the highest clinically achievable concentrations. Our PK/PD model was able to describe the interaction between fosfomycin and sulbactam in vitro. Bacterial kill was mainly driven by sulbactam, with fosfomycin augmentation. FOS/SUL regimens that included sulbactam at 4 g every 8 h demonstrated a probability of target attainment of 1-log10 kill at 24 h of ∼69 to 76%, compared to ∼15 to 30% with monotherapy regimens at the highest doses. The reduction in the MIC values and the achievement of a moderate PTA of a 2-log10 reduction in bacterial burden demonstrated that FOS/SUL may potentially be effective against some CR-AB infections.

scholarly journals Elimination of Extracellular Adenosine Triphosphate for the Rapid Prediction of Quantitative Plate Counts in 24 h Time-Kill Studies against Carbapenem-Resistant Gram-Negative Bacteria

2020 ◽  
Vol 8 (10) ◽  
pp. 1489
Author(s):  
Yiying Cai ◽  
Jonathan J. Ng ◽  
Hui Leck ◽  
Jocelyn Q. Teo ◽  
Jia-Xuan Goh ◽  
...  
Keyword(s):  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Carbapenem Resistant ◽  
Infection Models ◽  
Rapid Prediction ◽  
Atp Bioluminescence ◽  
Plate Counts ◽  
Time Kill

Traditional in vitro time-kill studies (TKSs) require viable plating, which is tedious and time-consuming. We used ATP bioluminescence, with the removal of extracellular ATP (EC-ATP), as a surrogate for viable plating in TKSs against carbapenem-resistant Gram-negative bacteria (CR-GNB). Twenty-four-hour TKSs were conducted using eight clinical CR-GNB (two Escherichia coli, two Klebsiella spp., two Acinetobacter baumannii, two Pseudomonas aeruginosa) with multiple single and two-antibiotic combinations. ATP bioluminescence and viable counts were determined at each timepoint (0, 2, 4, 8, 24 h), with and without apyrase treatment. Correlation between ATP bioluminescence and viable counts was determined for apyrase-treated and non-apyrase-treated samples. Receiver operator characteristic curves were plotted to determine the optimal luminescence threshold to discriminate between inhibitory/non-inhibitory and bactericidal/non-bactericidal combinations, compared to viable counts. After treatment of bacteria with 2 U/mL apyrase for 15 min at 37 °C, correlation to viable counts was significantly higher compared to untreated samples (p < 0.01). Predictive accuracies of ATP bioluminescence were also significantly higher for apyrase-treated samples in distinguishing inhibitory (p < 0.01) and bactericidal (p = 0.03) combinations against CR-GNB compared to untreated samples, when all species were collectively analyzed. We found that ATP bioluminescence can potentially replace viable plating in TKS. Our assay also has applications in in vitro and in vivo infection models.

scholarly journals Polymyxin Triple Combinations against Polymyxin-Resistant, Multidrug-Resistant, KPC-Producing Klebsiella pneumoniae

2020 ◽  
Vol 64 (8) ◽  
Author(s):  
Su Mon Aye ◽  
Irene Galani ◽  
Heidi Yu ◽  
Jiping Wang ◽  
Ke Chen ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Triple Therapy ◽  
Polymyxin B ◽  
Multidrug Resistant ◽  
Infection Model ◽  
Bacterial Killing ◽  
Standard Dosage ◽  
Time Kill

ABSTRACT Resistance to polymyxin antibiotics is increasing. Without new antibiotic classes, combination therapy is often required. We systematically investigated bacterial killing with polymyxin-based combinations against multidrug-resistant (including polymyxin-resistant), carbapenemase-producing Klebsiella pneumoniae. Monotherapies and double- and triple-combination therapies were compared to identify the most efficacious treatment using static time-kill studies (24 h, six isolates), an in vitro pharmacokinetic/pharmacodynamic model (IVM; 48 h, two isolates), and the mouse thigh infection model (24 h, six isolates). In static time-kill studies, all monotherapies (polymyxin B, rifampin, amikacin, meropenem, or minocycline) were ineffective. Initial bacterial killing was enhanced with various polymyxin B-containing double combinations; however, substantial regrowth occurred in most cases by 24 h. Most polymyxin B-containing triple combinations provided greater and more sustained killing than double combinations. Standard dosage regimens of polymyxin B (2.5 mg/kg of body weight/day), rifampin (600 mg every 12 h), and amikacin (7.5 mg/kg every 12 h) were simulated in the IVM. Against isolate ATH 16, no viable bacteria were detected across 5 to 25 h with triple therapy, with regrowth to ∼2-log10 CFU/ml occurring at 48 h. Against isolate BD 32, rapid initial killing of ∼3.5-log10 CFU/ml at 5 h was followed by a slow decline to ∼2-log10 CFU/ml at 48 h. In infected mice, polymyxin B monotherapy (60 mg/kg/day) generally was ineffective. With triple therapy (polymyxin B at 60 mg/kg/day, rifampin at 120 mg/kg/day, and amikacin at 300 mg/kg/day), at 24 h there was an ∼1.7-log10 CFU/thigh reduction compared to the starting inoculum for all six isolates. Our results demonstrate that the polymyxin B-rifampin-amikacin combination significantly enhanced in vitro and in vivo bacterial killing, providing important information for the optimization of polymyxin-based combinations in patients.

The Novel Aurora Kinase Inhibitor ENMD-2076 Has Potent Single Agent Activity against Multiple Myeloma (MM) in Vitro and in Vivo, and Shows Synergistic Activity in Combination with Lenalidomide

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 3660-3660 ◽  
Author(s):  
Xiaojing Wang ◽  
Anthony L. Sinn ◽  
Attaya Suvannasankha ◽  
Colin D. Crean ◽  
Li Chen ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Caspase 3 ◽  
Kinase Inhibitor ◽  
Single Agent ◽  
Synergistic Activity ◽  
Significant Activity ◽  
Aurora A Kinase ◽  
Free Base

Abstract ENMD-2076 is a novel, orally-active molecule that has been shown to have significant activity against Aurora A kinase as well as multiple receptor tyrosine kinases (RTK). We investigated the single agent activity of ENMD-2076 against MM cells in vitro and in vivo, and in combination with lenalidomide. ENMD-2076 free base showed significant cytotoxicity against MM cells with a mean LC50 of 3.84±0.86 μM at 48 hours in vitro. Cytotoxicity was associated with cleavage of caspase 3, 8, 9 and PARP, and loss of mitochondrial membrane potential as early as 6 hours. ENMD-2076 free base inhibited c-kit, FGFR-1, 3 and VEGFR1 and subsequently inhibition of downstream targets phosphorylated (p)-BAD, p-Foxo1a and p-GSK-3β was observed at 6 hours. NOD/SCID mice implanted with H929 human plasmacytoma xenografts and treated for 30 days with 50, 100, 200mg/kg/d ENMD-2076 showed a dose-dependent inhibition of tumor growth (Figure 1), with minimal toxicity as assessed by the stable weight of treated animals. Immunohistochemical staining of tumors from sacrificed animals showed significant reduction in Ki67 at all dose levels of treatment compared to control tumors. An increase in cleaved caspase-3 was observed on Western blot from the lysates of H929 tumors obtained from treated animals. ENMD-2076 free base also showed synergistic cytotoxic activity when combined with lenalidomide against H929, MM1.R and MM1.S cells as assessed by MTT assay and Annexin-V/PI staining. Using the Chou-Talalay method, the combination indices (CI) were < 1 for all three cell lines across a range of concentrations of ENMD-2076 free base (0.25–1.0 μM) plus lenalidomide (2.5–10 μM) indicating synergistic activity (CI=0.362 H929; CI=0.315 MM1.R; CI=0.415 MM1.S). Our results provide rationale for the investigation of ENMD-2076 alone and in combination with lenalidomide in patients with multiple myeloma. Figure Figure

scholarly journals In VitroandIn VivoActivities of OP0595, a New Diazabicyclooctane, against CTX-M-15-Positive Escherichia coli and KPC-Positive Klebsiella pneumoniae

2016 ◽  
Vol 60 (5) ◽  
pp. 3001-3006 ◽  
Author(s):  
Akihiro Morinaka ◽  
Yuko Tsutsumi ◽  
Keiko Yamada ◽  
Yoshihiro Takayama ◽  
Shiro Sakakibara ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Klebsiella Pneumoniae ◽  
Infection Model ◽  
Gram Negative Bacteria ◽  
Content Type ◽  
Effective Combination ◽  
Time Kill ◽  
Lactamase Inhibitor

ABSTRACTGram-negative bacteria are evolving to produce β-lactamases of increasing diversity that challenge antimicrobial chemotherapy. OP0595 is a new diazabicyclooctane serine β-lactamase inhibitor which acts also as an antibiotic and as a β-lactamase-independent β-lactam “enhancer” againstEnterobacteriaceae. Here we determined the optimal concentration of OP0595 in combination with piperacillin, cefepime, and meropenem, in addition to the antibacterial activity of OP0595 alone and in combination with cefepime, inin vitrotime-kill studies and anin vivoinfection model against five strains of CTX-M-15-positiveEscherichia coliand five strains of KPC-positiveKlebsiella pneumoniae. An OP0595 concentration of 4 μg/ml was found to be sufficient for an effective combination with all three β-lactam agents. In bothin vitrotime-kill studies and anin vivomodel of infection, cefepime-OP0595 showed stronger efficacy than cefepime alone against all β-lactamase-positive strains tested, whereas OP0595 alone showed weaker or no efficacy. Taken together, these data indicate that combinational use of OP0595 and a β-lactam agent is important to exert the antimicrobial functions of OP0595.

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