In Vitro Discordance with In Vivo Activity: Humanized Exposures of Ceftazidime-Avibactam (Caz-Avi), Aztreonam (ATM), and Tigecycline (TGC) Alone and in Combination Against New Delhi Metallo-β-Lactamase-Producing (NDM) Klebsiella pneumoniae (KP) in a Murine Lung Infection Model

ABSTRACT Recent findings have identified Klebsiella pneumoniae strains that are pan-β-lactam susceptible (PBL-S) but piperacillin-tazobactam resistant (TZP-R) in vitro. We assessed the efficacy of a humanized exposure of piperacillin-tazobactam (TZP) against 12 TZP-R/PBL-S K. pneumoniae isolates in an immunocompromised murine lung infection model. Discordance between the in vitro resistance profile and the in vivo efficacy of human-simulated TZP exposures against this phenotypic profile was observed. Additional studies are required to define the clinical implications of these TZP-R/PBL-S strains.

Download Full-text

In Vitro Discordance with In Vivo Activity: Humanized Exposures of Ceftazidime-Avibactam, Aztreonam, and Tigecycline Alone and in Combination against New Delhi Metallo-β-Lactamase-Producing Klebsiella pneumoniae in a Murine Lung Infection Model

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00486-17 ◽

2017 ◽

Vol 61 (7) ◽

Cited By ~ 26

Author(s):

M. L. Monogue ◽

L. M. Abbo ◽

R. Rosa ◽

J. F. Camargo ◽

O. Martinez ◽

...

Keyword(s):

Klebsiella Pneumoniae ◽

Lung Infection ◽

Multidrug Resistant ◽

Infection Model ◽

New Delhi ◽

Beta Lactamase ◽

Bacterial Reduction ◽

Content Type

ABSTRACT The management of infections with New Delhi metallo-beta-lactamase-1 (NDM)-producing bacteria remains clinically challenging given the multidrug resistant (MDR) phenotype associated with these bacteria. Despite resistance in vitro, ceftazidime-avibactam previously demonstrated in vivo activity against NDM-positive Enterobacteriaceae. Herein, we observed in vitro synergy with ceftazidime-avibactam and aztreonam against an MDR Klebsiella pneumoniae harboring NDM. In vivo, humanized doses of ceftazidime-avibactam monotherapy resulted in >2 log10 CFU bacterial reduction; therefore, no in vivo synergy was observed.

Download Full-text

In VivoPharmacodynamic Target Assessment of Delafloxacin against Staphylococcus aureus, Streptococcus pneumoniae, and Klebsiella pneumoniae in a Murine Lung Infection Model

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00647-16 ◽

2016 ◽

Vol 60 (8) ◽

pp. 4764-4769 ◽

Cited By ~ 26

Author(s):

Alexander J. Lepak ◽

David R. Andes

Keyword(s):

Staphylococcus Aureus ◽

Single Dose ◽

Streptococcus Pneumoniae ◽

Klebsiella Pneumoniae ◽

Dose Response ◽

Lung Infection ◽

Infection Model ◽

Content Type ◽

Murine Lung

ABSTRACTDelafloxacin is a broad-spectrum anionic fluoroquinolone under development for the treatment of bacterial pneumonia. The goal of the study was to determine the pharmacokinetic/pharmacodynamic (PK/PD) targets in the murine lung infection model forStaphylococcus aureus,Streptococcus pneumoniae, andKlebsiella pneumoniae. Four isolates of each species were utilized forin vivostudies: forS. aureus, one methicillin-susceptible and three methicillin-resistant isolates;S. pneumoniae, two penicillin-susceptible and two penicillin-resistant isolates;K. pneumoniae, one wild-type and three extended-spectrum beta-lactamase-producing isolates. MICs were determined using CLSI methods. A neutropenic murine lung infection model was utilized for all treatment studies, and drug dosing was by the subcutaneous route. Single-dose plasma pharmacokinetics was determined in the mouse model after administration of 2.5, 10, 40, and 160 mg/kg. Forin vivostudies, 4-fold-increasing doses of delafloxacin (range, 0.03 to 160 mg/kg) were administered every 6 h (q6h) to infected mice. Treatment outcome was measured by determining organism burden in the lung (CFU counts) at the end of each experiment (24 h). The Hill equation for maximum effect (Emax) was used to model the dose-response data. The magnitude of the PK/PD index, the area under the concentration-time curve over 24 h in the steady state divided by the MIC (AUC/MIC), associated with net stasis and 1-log kill endpoints was determined in the lung model for all isolates. MICs ranged from 0.004 to 1 mg/liter. Single-dose PK parameter ranges include the following: for maximum concentration of drug in serum (Cmax), 2 to 70.7 mg/liter; AUC from 0 h to infinity (AUC0–∞), 2.8 to 152 mg · h/liter; half-life (t1/2), 0.7 to 1 h. At the start of therapy mice had 6.3 ± 0.09 log10CFU/lung. In control mice the organism burden increased 2.1 ± 0.44 log10CFU/lung over the study period. There was a relatively steep dose-response relationship observed with escalating doses of delafloxacin. Maximal organism reductions ranged from 2 log10to more than 4 log10. The median free-drug AUC/MIC magnitude associated with net stasis for each species group was 1.45, 0.56, and 40.3 forS. aureus,S. pneumoniae, andK. pneumoniae, respectively. AUC/MIC targets for the 1-log kill endpoint were 2- to 5-fold higher. Delafloxacin demonstratedin vitroandin vivopotency against a diverse group of pathogens, including those with phenotypic drug resistance to other classes. These results have potential relevance for clinical dose selection and evaluation of susceptibility breakpoints for delafloxacin for the treatment of lower respiratory tract infections involving these pathogens.

Download Full-text

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

Journal of Antimicrobial Chemotherapy ◽

10.1093/jac/dkz330 ◽

2019 ◽

Vol 74 (11) ◽

pp. 3211-3216 ◽

Cited By ~ 13

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.

Download Full-text

Bactericidal Activities of Meropenem and Ertapenem against Extended-Spectrum-β-Lactamase-Producing Escherichia coli and Klebsiella pneumoniae in a Neutropenic Mouse Thigh Model

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00752-06 ◽

2007 ◽

Vol 51 (4) ◽

pp. 1481-1486 ◽

Cited By ~ 34

Author(s):

C. Andrew DeRyke ◽

Mary Anne Banevicius ◽

Hong Wei Fan ◽

David P. Nicolau

Keyword(s):

Escherichia Coli ◽

Klebsiella Pneumoniae ◽

Infection Model ◽

Bacterial Reduction ◽

Efficacy Analysis ◽

Percent Time ◽

Extended Spectrum ◽

Wide Range

ABSTRACT The purpose of this study was to examine the in vivo efficacies of meropenem and ertapenem against extended-spectrum-β-lactamase (ESBL)-producing isolates with a wide range of MICs. Human-simulated dosing regimens in mice were designed to approximate the free drug percent time above the MIC (fT>MIC) observed for humans following meropenem at 1 g every 8 h and ertapenem at 1 g every 24 h. An in vivo neutropenic mouse thigh infection model was used to examine the bactericidal effects against 31 clinical ESBL Escherichia coli and Klebsiella pneumoniae isolates and 2 non-ESBL isolates included for comparison at a standard 105 inoculum. Three isolates were examined at a high 107 inoculum as well. Meropenem displayed greater in vitro potency, with a median MIC (range) (μg/ml) of 0.125 (0.03 to 32), than did ertapenem, with 0.5 (0.012 to 128). Seven of the 31 ESBL isolates were removed from the efficacy analysis due to their inability to establish infection in the mouse model. When MICs were ≤1.5 μg/ml for ertapenem (≤0.5 μg/ml for meropenem), similar reductions in CFU (≈ 2-log kill) were observed for both ertapenem (fT>MIC ≥ 23%) and meropenem (fT>MIC ≥ 75%). Ertapenem showed bacterial regrowth for seven of eight isolates, with MICs of ≥2 μg/ml (fT>MIC ≤ 20%), while meropenem displayed antibacterial potency that varied from a static effect to a 1-log bacterial reduction in these isolates (fT>MIC = 30 to 65%). At a 107 inoculum, both agents eradicated bacteria due to adequate exposures (fT>MIC = 20 to 45%). Due to low MICs, no difference in bacterial kill was noted for the majority of ESBL isolates tested. However, for isolates with raised ertapenem MICs of ≥2 μg/ml, meropenem displayed sustained efficacy due to its greater in vitro potency and higher resultant fT>MIC.

Download Full-text

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

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00246-20 ◽

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.

Download Full-text

Yersiniabactin Is a Virulence Factor for Klebsiella pneumoniae during Pulmonary Infection

Infection and Immunity ◽

10.1128/iai.00372-06 ◽

2007 ◽

Vol 75 (3) ◽

pp. 1463-1472 ◽

Cited By ~ 112

Author(s):

Matthew S. Lawlor ◽

Christopher O'Connor ◽

Virginia L. Miller

Keyword(s):

Klebsiella Pneumoniae ◽

Iron Acquisition ◽

Infection Model ◽

Mutagenesis Screen ◽

Starting Point ◽

In Vivo Growth ◽

Isogenic Mutants ◽

Isogenic Strains

ABSTRACT Iron acquisition systems are essential for the in vivo growth of bacterial pathogens. Despite the epidemiological importance of Klebsiella pneumoniae, few experiments have examined the importance of siderophores in the pathogenesis of this species. A previously reported signature-tagged mutagenesis screen identified an attenuated strain that featured an insertional disruption in ybtQ, which encodes a transporter for the siderophore yersiniabactin. We used this finding as a starting point to evaluate the importance of siderophores in the physiology and pathogenesis of K. pneumoniae. Isogenic strains carrying in-frame deletions in genes required for the synthesis of either enterobactin or yersiniabactin were constructed, and the growth of these mutants was examined both in vitro and in vivo using an intranasal infection model. The results suggest divergent functions for each siderophore in different environments, with enterobactin being more important for growth in vitro under iron limitation than in vivo and the reverse being true for the yersiniabactin locus. These observations represent the first examination of isogenic mutants in iron acquisition systems for K. pneumoniae and may indicate that the acquisition of nonenterobactin siderophores is an important step in the evolution of virulent enterobacterial strains.

Download Full-text

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

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.02704-15 ◽

2016 ◽

Vol 60 (5) ◽

pp. 3001-3006 ◽

Cited By ~ 11

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.

Download Full-text

1066. In Vitro and in Vivo Antimicrobial Activity of Cefiderocol and Comparators against Achromobacter spp

Open Forum Infectious Diseases ◽

10.1093/ofid/ofab466.1260 ◽

2021 ◽

Vol 8 (Supplement_1) ◽

pp. S625-S626

Author(s):

Ryuichiro Nakai ◽

Ayaka makino ◽

Hitomi Hama ◽

Toriko Yoshitomi ◽

Rio Nakamura ◽

...

Keyword(s):

Rat Model ◽

Murine Model ◽

Lung Infection ◽

Vitro Activity ◽

Infection Model ◽

In Vitro Activity ◽

Independent Contractor ◽

In Vivo Efficacy

Abstract Background Achromobacter spp. is intrinsically resistant to multiple antibiotics, and the treatment options are limited. Cefiderocol (CFDC), a siderophore cephalosporin approved in US and EU, is active against a wide variety of aerobic Gram-negative bacteria, including carbapenem-resistant strains. In this study, in vitro and in vivo antibacterial activity of CFDC against Achromobacter spp. was evaluated. Methods A total of 334 global isolates collected by IHMA from 39 countries in 2015-2019 were used. Minimum inhibitory concentrations (MICs) of CFDC and comparators were determined by broth microdilution method using iron-depleted CAMHB or CAMHB, respectively, as recommended by CLSI guidelines. In vivo efficacy of CFDC was compared with meropenem (MEM), piperacillin-tazobactam (PIP/TAZ), ceftazidime (CAZ), and ciprofloxacin (CIP) in a neutropenic murine lung infection model (n=5), and compared with MEM in a immunocompetent rat lung infection model (n=3-7) caused by 2 A. xylosoxydans. In the murine model, treatment was given 2, 5, and 8 hours post-infection, and the numbers of viable cfu in lungs were determined 24 hours post-infection. In the rat model, the humanized PK in plasma resulting from CFDC 2 g every 8 h (3-h infusion) or meropenem 1 g every 8 h (0.5-h infusion) were recreated via continuous intravenous infusion for 4 days, following which cfu in lungs were determined. Results CFDC showed in vitro activity with MIC50/90 of 0.06/0.5 µg/mL against 334 Achromobacter spp. Only 7 isolates (2.1%) had MICs > 4 µg/mL. These were the lowest values among all compound tested (Table). In the murine model, CFDC caused > 1.5 log10 decrease of viable cfu in lungs at 100 mg/kg dose (%fT >MIC: < 50%) from baseline control against both of strains (CFDC MIC: 0.5 and 2 µg/mL) (P< 0.05). No decrease of cfu in lungs was observed for the comparators at 100 mg/kg (MEM, PIP/TAZ, CAZ, and CIP MICs were >16, >64, >32, and >8 µg/mL, respectively). In the rat model, humanized CFDC dosing reduced the viable cfu by >1 log10 CFU/lung compared with baseline controls (P< 0.05). MEM showed no significant activity. In vitro activity of CFDC and comparator agents against Achromobacter spp. 334 Achromobacter spp. isolates collected from 2015 and 2019. The majority of isolates tested were A. xylosoxidans (312/334; 93.4%), followed by A. insolitus (11/334; 3.3%), Achromobacter sp. (8/334; 2.4%), A. denitrificans (2/334; 0.6%), and A. piechaudii (1/334; 0.3%). Conclusion CFDC showed potent in vivo efficacy reflecting in vitro activity against A. xylosoxidans. The results suggested that CFDC has the potential to be an effective therapeutic option for Achromobacter spp. infections. Disclosures Ryuichiro Nakai, MSc, Shionogi TechnoAdvance Research & Co., Ltd. (Employee) Ayaka makino, BSc, Shionogi TechnoAdvance Research & Co., Ltd. (Employee) Toriko Yoshitomi, -, Shionogi TechnoAdvance Research & Co., Ltd. (Employee) Rio Nakamura, BSc, Shionogi TechnoAdvance Research & Co., Ltd. (Employee) Meredith Hackel, PhD MPH, IHMA (Employee)Pfizer, Inc. (Independent Contractor) Miki Takemura, MS, SHIONOGI & CO., LTD. (Employee) Daniel F. Sahm, PhD, IHMA (Employee)Pfizer, Inc. (Independent Contractor) Yoshinori Yamano, PhD, Shionogi (Employee)

Download Full-text

1058. In Vitro and In Vivo Antibacterial Activity of Cefiderocol against Burkholderia spp

Open Forum Infectious Diseases ◽

10.1093/ofid/ofab466.1252 ◽

2021 ◽

Vol 8 (Supplement_1) ◽

pp. S621-S621

Author(s):

Merime Oota ◽

Hitomi Hama ◽

Toriko Yoshitomi ◽

Rio Nakamura ◽

Miki Takemura ◽

...

Keyword(s):

Respiratory Infections ◽

Lung Infection ◽

Bacterial Suspension ◽

Infection Model ◽

Rat Lung ◽

Independent Contractor ◽

Broth Microdilution Method ◽

Tract Infections

Abstract Background Burkholderia spp. is an opportunistic pathogen associated with respiratory infections. Cefiderocol (CFDC), a siderophore cephalosporin approved in US and EU, is active in vitro against carbapenem-resistant Gram-negative bacteria including Burkholderia spp. This study examined in vitro and in vivo activity of CFDC against Burkholderia spp. Methods MICs of CFDC and 13 marketed antibacterial drugs against 462 clinical isolates of Burkholderia spp. collected in 2014 - 2019 in 13 countries were determined by broth microdilution method according to CLSI guidelines. Only for CFDC, iron-depleted CAMHB was used. In a rat lung infection model, B. cepacia ATCC 25416 (CFDC MIC: ≤ 0.031 μg/mL, MEM MIC: 4 μg/mL) was used. Male CD (SD, immunocompetent, n=4-5) rats were infected by intrabronchial inoculation of the bacterial suspension including 1% nutrient agar. The humanized PK in plasma by administration of CFDC 2 g every 8 h (3-h infusion) and MEM 1 g every 8 h (0.5-h infusion) were recreated via the continuous intravenous infusion for 4 days, and the viable cfu in lungs were counted. Results Against 462 strains, including 185 MEM non-susceptible isolates, CFDC showed MIC50/MIC90 of ≤ 0.031/1 µg/mL, which was the lowest among the tested antibiotics. Among 185 MEM non-susceptible isolates, 94% of the isolates exhibited ≤ 4 µg/mL of CFDC MIC. In a rat lung infection model, CFDC and MEM showed bactericidal activity with 2.8 and 2.4 log10 CFU/lung decrease compared with non-treated control, respectively. By recreating the humanized PK exposure in this model, 100% and ca.35% of fT >MIC of CFDC and MEM in plasma has been achieved, respectively. The bactericidal activities of both compounds vs B. cepacia ATCC 25416 would be reasonable because the fT >MIC achieved in this model exceeds the target fT >MIC (75% for CFDC and 26% for MEM against Acinetobacter baumannii, respectively) required to cause 1 log10 reduction in murine thigh infection models1,2). 1) M. Sabet. 2019. AAC 2) R. Nakamura. 2019. AAC In vitro activity of CFDC and comparator agents against Burkholderia spp. Conclusion CFDC has potential for treating respiratory tract infections caused by Burkholderia spp. In critically ill patients, the recommended dosing regimen achieves 100% of fT >MIC of ≤ 4 ug/mL3).3) N. Kawaguchi. 2021. AAC Disclosures Merime Oota, BSc, Shionogi TechnoAdvance Research & Co., Ltd. (Employee) Toriko Yoshitomi, -, Shionogi TechnoAdvance Research & Co., Ltd. (Employee) Rio Nakamura, BSc, Shionogi TechnoAdvance Research & Co., Ltd. (Employee) Miki Takemura, MS, SHIONOGI & CO., LTD. (Employee) Yoshinori Yamano, PhD, Shionogi (Employee) Meredith Hackel, PhD MPH, IHMA (Employee)Pfizer, Inc. (Independent Contractor) Daniel F. Sahm, PhD, IHMA (Employee)Pfizer, Inc. (Independent Contractor)

Download Full-text