scholarly journals In Vivo Efficacies and Pharmacokinetics of DX-619, a Novel Des-Fluoro(6) Quinolone, against Streptococcus pneumoniae in a Mouse Lung Infection Model

2006 ◽  
Vol 50 (1) ◽  
pp. 121-125 ◽  
Author(s):  
Yuichi Fukuda ◽  
Katsunori Yanagihara ◽  
Hideaki Ohno ◽  
Yasuhito Higashiyama ◽  
Yoshitsugu Miyazaki ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Mouse Lung ◽  
Infection Model ◽  
Time Curve ◽  
Concentration Time ◽  
Viable Bacteria ◽  
Effective Doses ◽  
The Mean ◽  
Lung Infections

ABSTRACT DX-619 is a novel des-fluoro(6) quinolone with potent activity against gram-positive pathogens. The in vivo activity of DX-619 against Streptococcus pneumoniae was compared with those of fluoro(6) quinolones, sitafloxacin, and ciprofloxacin in a mouse model. Two strains of S. pneumoniae were used: a penicillin-sensitive S. pneumoniae (PSSP) strain and a penicillin-resistant S. pneumoniae (PRSP) strain. Furthermore, these strains showed intermediate susceptibilities to ciprofloxacin. In murine lung infections caused by PSSP, the 50% effective doses (ED50s) of DX-619, sitafloxacin, and ciprofloxacin were 9.15, 11.1, and 127.6 mg/kg of body weight, respectively. Against PRSP-mediated pneumonia in mice, the ED50s of DX-619, sitafloxacin, and ciprofloxacin were 0.69, 4.84, and 38.75 mg/kg, respectively. The mean ± standard error of the mean viable bacterial counts in murine lungs infected with PSSP and treated with DX-619, sitafloxacin, ciprofloxacin (10 mg/kg twice daily), and saline (twice daily) were 1.75 ± 0.06, 1.92 ± 0.23, 6.48 ± 0.28, and 7.57 ± 0.13 log10 CFU/ml, respectively. Furthermore, the numbers of viable bacteria in lungs infected with PRSP and treated with the three agents and not treated (control) were 1.73 ± 0.04, 2.28 ± 0.17, 4.61 ± 0.59, and 5.54 ± 0.72 log10 CFU/ml, respectively. DX-619 and sitafloxacin significantly decreased the numbers of viable bacteria in the lungs compared to the numbers in the lungs of ciprofloxacin-treated and untreated mice. The pharmacokinetic parameter of the area under the concentration-time curve (AUC)/MIC ratio in the lungs for DX-619, sitafloxacin, and ciprofloxacin were 171.0, 21.92, and 1.22, respectively. The AUC/MIC ratio in the lungs was significantly higher for DX-619 than for sitafloxacin and ciprofloxacin. Our results suggest that DX-619 and sitafloxacin are potent against both PSSP and PRSP in our mouse pneumonia model.

scholarly journals In Vivo Pharmacodynamic Target Assessment of Antofloxacin against Streptococcus pneumoniae and Staphylococcus aureus in a Neutropenic Murine Pneumonia Model

2020 ◽  
Vol 64 (12) ◽  
Author(s):  
Yu-Feng Zhou ◽  
Ping Liu ◽  
Shu-He Dai ◽  
Jian Sun ◽  
Ya-Hong Liu ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Streptococcus Pneumoniae ◽  
Free Drug ◽  
Time Curve ◽  
Content Type ◽  
Concentration Time ◽  
Lung Epithelial ◽  
The Mean ◽  
And Staphylococcus Aureus

ABSTRACT We determined in vivo efficacy and target PK/PD exposures of antofloxacin against Streptococcus pneumoniae and Staphylococcus aureus in the murine pneumonia model. The mean plasma free drug area under the concentration-time curve/MIC (fAUC/MIC) targets associated with stasis and 1-log10 and 2-log10 kill effects were 8.93, 19.2, and 48.1, respectively, for S. pneumoniae, whereas they were 30.5, 55.4, and 115.8, respectively, for S. aureus. The fAUC/MIC targets in murine lung epithelial lining fluids (ELF) for the same endpoints were nearly 2-fold higher than those in plasma.

scholarly journals In Vivo Efficacy of a New Quinolone, DQ-113, against Streptococcus pneumoniae in a Mouse Model

2003 ◽  
Vol 47 (12) ◽  
pp. 3699-3703 ◽  
Author(s):  
Yoshiko Otsu ◽  
Katsunori Yanagihara ◽  
Yuichi Fukuda ◽  
Yoshitsugu Miyazaki ◽  
Kazuhiro Tsukamoto ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Mouse Model ◽  
Survival Rates ◽  
Treated Group ◽  
The Other ◽  
Time Curve ◽  
In Vivo Efficacy ◽  
Viable Bacteria ◽  
Effective Doses

ABSTRACT DQ-113 is a new quinolone with potent activity against gram-positive pathogens. The in vivo activity of DQ-113 against Streptococcus pneumoniae was compared with those of gatifloxacin and ciprofloxacin in a mouse model. For this purpose, two strains of S. pneumoniae were used: penicillin-susceptible S. pneumoniae (PSSP) and penicillin-resistant S. pneumoniae (PRSP). The survival rates of mice infected with PSSP and PRSP at 14 days after infection were 80% in the DQ-113-treated group and 0 to 10% in the other three groups. In murine infections caused by PSSP, the 50% effective doses (ED50s) of DQ-113, gatifloxacin, and ciprofloxacin were 6.0, 41.3, and 131.6 mg/kg, respectively. Against PRSP-caused pneumonia in mice, the ED50s of DQ-113, gatifloxacin, and ciprofloxacin were 7.6, 64.7, and 125.9 mg/kg, respectively. Compared with the other drugs, DQ-113 showed excellent therapeutic efficacy and eradicated viable bacteria in both PSSP- and PRSP-infected mice. The means ± standard errors of the means of viable bacterium counts in the lungs of gatifloxacin-treated, ciprofloxacin-treated, and untreated control mice infected with PSSP were 2.91 ± 0.34, 3.13 ± 0.48, and 3.86 ± 0.80 log10CFU/ml, respectively. The same counts in mice infected with PRSP treated with the same three agents were 6.57 ± 0.99, 6.54 ± 0.40, and 7.17 ± 0.43 log10 CFU/ml, respectively. DQ-113 significantly decreased the number of viable bacteria in the lungs compared with gatifloxacin and ciprofloxacin. Of the drugs analyzed, the pharmacokinetic-pharmacodynamic parameter of area under the concentration-time curve (AUC)/MIC ratio for DQ-113 was significantly higher than those for gatifloxacin and ciprofloxacin. Our results suggest that DQ-113 has potent in vivo efficacy against both PSSP and PRSP.

scholarly journals Pharmacodynamic Profile of Telithromycin against Macrolide- and Fluoroquinolone-Resistant Streptococcus pneumoniae in a Neutropenic Mouse Thigh Model

2005 ◽  
Vol 49 (1) ◽  
pp. 188-194 ◽  
Author(s):  
Pamela R. Tessier ◽  
Holly M. Mattoes ◽  
Prachi K. Dandekar ◽  
Charles H. Nightingale ◽  
David P. Nicolau
Keyword(s):  
Streptococcus Pneumoniae ◽  
Infection Model ◽  
Pharmacokinetic Studies ◽  
Time Curve ◽  
Phenotypic Resistance ◽  
Concentration Time ◽  
Pharmacodynamic Profile

ABSTRACT The new ketolide telithromycin has potent in vitro activity against Streptococcus pneumoniae, including strains resistant to penicillin, macrolides, and fluoroquinolones. The aim of the present study was to define the pharmacodynamic profile of telithromycin against S. pneumoniae strains with various resistance profiles in an in vivo system. Ten S. pneumoniae strains were studied; seven exhibited penicillin resistance, six demonstrated macrolide resistance, and two exhibited gatifloxacin resistance. The telithromycin MICs for all isolates were ≤0.5 μg/ml. Using the murine thigh infection model, CD-1/ICR mice were rendered neutropenic and were then inoculated with 105 to 106 CFU of S. pneumoniae per thigh. Telithromycin was administered orally at doses ranging from 25 to 800 mg/kg of body weight/day, with the doses administered one, two, three, or four times a day. The activity of telithromycin was assessed by determination of the change in the bacterial density in thigh tissue after 24 h of treatment for each treatment group and the untreated controls. Pharmacokinetic studies of telithromycin were conducted in infected, neutropenic animals. The levels of protein binding by telithromycin in mice ranged from 70 to 95% over the observed range of pharmacokinetic concentrations. By using either the total or the free concentrations of telithromycin, the area under the concentration-time curve (AUC)/MIC ratio was a strong determinant of the response against S. pneumoniae, regardless of the phenotypic resistance profile. The maximal efficacy (the 95% effective dose) against this cohort of S. pneumoniae strains and bacterial inhibition (stasis) of telithromycin were predicted by ratios of the AUC for the free drug concentration/MIC of approximately 1,000 and 200, respectively.

scholarly journals Activity of Amoxicillin-Clavulanate against Penicillin-Resistant Streptococcus pneumoniae in an Experimental Respiratory Infection Model in Rats

1998 ◽  
Vol 42 (4) ◽  
pp. 813-817 ◽  
Author(s):  
Gillian M. Smith ◽  
Brian Slocombe ◽  
Karen H. Abbott ◽  
Linda W. Mizen
Keyword(s):  
Streptococcus Pneumoniae ◽  
Infection Model ◽  
Time Curve ◽  
Penicillin Binding Proteins ◽  
Amoxicillin Clavulanate ◽  
Potassium Clavulanate ◽  
Differential Binding ◽  
High Doses ◽  
Oral Doses

ABSTRACT High doses of amoxicillin, equivalent to those produced by 500- and 750-mg oral doses in humans (area under the plasma concentration-time curve), were effective against a penicillin-resistant strain ofStreptococcus pneumoniae in an experimental respiratory tract infection in immunocompromised rats; this superior activity confirms the results of previous studies. An unexpected enhancement of amoxicillin’s antibacterial activity in vivo against penicillin-resistant and -susceptible S. pneumoniaestrains was observed when subtherapeutic doses of amoxicillin were coadministered with the β-lactamase inhibitor potassium clavulanate. The reason for this enhancement was unclear since these organisms do not produce β-lactamase. The differential binding of clavulanic acid and amoxicillin to penicillin-binding proteins may have contributed to the observed effects.

scholarly journals In Vivo Pharmacodynamic Characterization of a Novel Odilorhabdin Antibiotic, NOSO-502, against Escherichia coli and Klebsiella pneumoniae in a Murine Thigh Infection Model

2018 ◽  
Vol 62 (9) ◽  
Author(s):  
Miao Zhao ◽  
Alexander J. Lepak ◽  
Karen Marchillo ◽  
Jamie VanHecker ◽  
David R. Andes
Keyword(s):  
Escherichia Coli ◽  
Klebsiella Pneumoniae ◽  
Subcutaneous Administration ◽  
Dose Fractionation ◽  
Infection Model ◽  
Pharmacokinetic Studies ◽  
Time Curve ◽  
Content Type ◽  
The Mean

ABSTRACT NOSO-502 is a novel odilorhabdin antibiotic with potent activity against Enterobacteriaceae. The goal of these studies was to determine which pharmacokinetic/pharmacodynamic (PK/PD) indices and magnitude best correlated with efficacy in the murine thigh infection model. Six Escherichia coli and 6 Klebsiella pneumoniae isolates were utilized. MICs were determined using CLSI methods and ranged from 1 to 4 mg/liter. A neutropenic murine thigh infection model was utilized for all treatment studies. Single-dose plasma pharmacokinetics were determined in mice after subcutaneous administration of 7.81, 31.25, 125, and 500 mg/kg of body weight. Pharmacokinetic studies exhibited peak concentration (Cmax) values of 1.49 to 84.6 mg/liter, area under the concentration-time curve from 0 h to infinity (AUC0–∞) values of 1.94 to 352 mg · h/liter, and beta elimination half-lives of 0.41 to 1.1 h. Dose fractionation studies were performed using total drug doses of 7.81 mg/kg to 2,000 mg/kg fractionated into regimens of every 3 h (q3h), q6h, q12h, or q24h. Nonlinear regression analysis demonstrated that AUC/MIC was the PK/PD parameter that best correlated with efficacy (R2, 0.86). In subsequent studies, we used the neutropenic murine thigh infection model to determine the magnitude of NOSO-502 AUC/MIC needed for the efficacy against a diverse group of Enterobacteriaceae. Mice were treated with 4-fold-increasing doses (range, 3.91 to 1,000 mg/kg) of NOSO-502 every 6 h. The mean 24-h free-drug AUC/MIC (fAUC)/MIC) magnitudes associated with net stasis and 1-log kill endpoint for K. pneumoniae were 4.22 and 17.7, respectively. The mean fAUC/MIC magnitude associated with net stasis endpoint for E. coli was 10.4. NOSO-502 represents a promising novel, first-in-class odilorhabdin antibiotic with in vivo potency against Enterobacteriaceae.

scholarly journals In Vivo Efficacies and Pharmacokinetics of DX-619, a Novel Des-Fluoro(6) Quinolone, against Streptococcus pneumoniae in a Mouse Lung Infection Model

2006 ◽  
Vol 50 (3) ◽  
pp. 1122-1122
Author(s):  
Yuichi Fukuda ◽  
Katsunori Yanagihara ◽  
Hideaki Ohno ◽  
Yasuhito Higashiyama ◽  
Yoshitsugu Miyazaki ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Lung Infection ◽  
Mouse Lung ◽  
Infection Model

scholarly journals In Vivo Pharmacodynamics of Omadacycline against Staphylococcus aureus in the Neutropenic Murine Thigh Infection Model

2019 ◽  
Vol 63 (7) ◽  
Author(s):  
Alexander J. Lepak ◽  
Miao Zhao ◽  
Karen Marchillo ◽  
Jamie VanHecker ◽  
David R. Andes
Keyword(s):  
Staphylococcus Aureus ◽  
Infection Model ◽  
Time Curve ◽  
Methicillin Resistant ◽  
Content Type ◽  
Concentration Time ◽  
Mrsa Strains

ABSTRACT Omadacycline is a novel aminomethylcycline antibiotic with potent activity against Staphylococcus aureus, including methicillin-susceptible S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA). We investigated the pharmacodynamic activity of omadacycline against 10 MSSA/MRSA strains in a neutropenic murine thigh model. The median 24-h area under the concentration-time curve (AUC)/MIC values associated with net stasis and 1-log kill were 21.9 and 57.7, respectively.

scholarly journals Comparative Efficacies of Human Simulated Exposures of Tedizolid and Linezolid against Staphylococcus aureus in the Murine Thigh Infection Model

2012 ◽  
Vol 56 (8) ◽  
pp. 4403-4407 ◽  
Author(s):  
R. A. Keel ◽  
P. R. Tessier ◽  
J. L. Crandon ◽  
D. P. Nicolau
Keyword(s):  
Staphylococcus Aureus ◽  
Bacterial Density ◽  
Infection Model ◽  
Immunocompetent Mouse ◽  
Time Curve ◽  
Free Concentration ◽  
Content Type ◽  
The Mean

ABSTRACTTedizolid (formally torezolid) is an expanded-spectrum oxazolidinone with enhancedin vitropotency against Gram-positive pathogens, including methicillin-susceptibleStaphylococcus aureus(MSSA) and methicillin-resistantS. aureus(MRSA). The efficacies of human simulated exposures of tedizolid and linezolid againstS. aureusin an immunocompetent mouse thigh model over 3 days were compared. Four strains of MRSA and one of MSSA with tedizolid and linezolid MICs ranging from 0.25 to 0.5 and from 2 to 4 μg/ml, respectively, were utilized. Tedizolid or linezolid was administered in a regimen simulating a human steady-state 24-h area under the free concentration-time curve of 200 mg every 24 h (Q24) or 600 mg Q12, respectively. Thighs were harvested after 4, 8, 12, 24, 36, 48, and 72 h, and efficacy was determined by the change in bacterial density. The mean bacterial density in control mice increased over the 3-day period. After 24 h of treatment, a reduction in bacterial density of ≥1 log CFU was observed for both the tedizolid and linezolid treatments. Antibacterial activity was enhanced for both agents with a reduction of ≥2.6 log CFU after 72 h of treatment. Any statistically significant differences (P≤ 0.05) in efficacy between the agents were transient and did not persist throughout the 72-h treatment period. The tedizolid and linezolid regimens demonstrated similarin vivoefficacies against theS. aureusisolates tested. Both agents were bacteriostatic at 24 h and bactericidal on the third day of treatment. These data support the clinical utility of tedizolid for skin and skin structure infections caused byS. aureus, as well as the bactericidal activity of the oxazolidinones after 3 days of treatment.

scholarly journals Pharmacokinetics/Pharmacodynamics of Peptide Deformylase Inhibitor GSK1322322 against Streptococcus pneumoniae, Haemophilus influenzae, and Staphylococcus aureus in Rodent Models of Infection

2015 ◽  
Vol 60 (1) ◽  
pp. 180-189 ◽  
Author(s):  
Jennifer Hoover ◽  
Thomas Lewandowski ◽  
Robert J. Straub ◽  
Steven J. Novick ◽  
Peter DeMarsh ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Streptococcus Pneumoniae ◽  
Haemophilus Influenzae ◽  
Lung Model ◽  
Peptide Deformylase ◽  
Dose Fractionation ◽  
Mouse Lung ◽  
Time Curve ◽  
Content Type

ABSTRACTGSK1322322 is a novel inhibitor of peptide deformylase (PDF) with goodin vitroactivity against bacteria associated with community-acquired pneumonia and skin infections. We have characterized thein vivopharmacodynamics (PD) of GSK1322322 in immunocompetent animal models of infection withStreptococcus pneumoniaeandHaemophilus influenzae(mouse lung model) and withStaphylococcus aureus(rat abscess model) and determined the pharmacokinetic (PK)/PD index that best correlates with efficacy and its magnitude. Oral PK studies with both models showed slightly higher-than-dose-proportional exposure, with 3-fold increases in area under the concentration-time curve (AUC) with doubling doses. GSK1322322 exhibited dose-dependentin vivoefficacy against multiple isolates ofS. pneumoniae,H. influenzae, andS. aureus. Dose fractionation studies with twoS. pneumoniaeandS. aureusisolates showed that therapeutic outcome correlated best with the free AUC/MIC (fAUC/MIC) index inS. pneumoniae(R2, 0.83), whereasfAUC/MIC and free maximum drug concentration (fCmax)/MIC were the best efficacy predictors forS. aureus(R2, 0.9 and 0.91, respectively). Median dailyfAUC/MIC values required for stasis and for a 1-log10reduction in bacterial burden were 8.1 and 14.4 for 11S. pneumoniaeisolates (R2, 0.62) and 7.2 and 13.0 for fiveH. influenzaeisolates (R2, 0.93). The data showed that for eightS. aureusisolates,fAUC correlated better with efficacy thanfAUC/MIC (R2, 0.91 and 0.76, respectively), as efficacious AUCs were similar for all isolates, independent of their GSK1322322 MIC (range, 0.5 to 4 μg/ml). MedianfAUCs of 2.1 and 6.3 μg · h/ml were associated with stasis and 1-log10reductions, respectively, forS. aureus.

scholarly journals Efficacy of Aerosolized Rifaximin versus Tobramycin for Treatment ofPseudomonas aeruginosaPneumonia in Mice

2019 ◽  
Vol 63 (7) ◽  
Author(s):  
Brandon D. Kirby ◽  
Roy Al Ahmar ◽  
T. Ryan Withers ◽  
Meagan E. Valentine ◽  
Monica Valentovic ◽  
...  
Keyword(s):  
Bacterial Species ◽  
Inhalation Therapy ◽  
Mouse Lung ◽  
Infection Model ◽  
Content Type ◽  
Dose Treatment ◽  
Alginate Production ◽  
Lung Infections

ABSTRACTPseudomonas aeruginosais a Gram-negative opportunistic bacterial pathogen that can cause chronic lung infections in patients with cystic fibrosis (CF). The current preferred treatment for CF lung infections includes inhaled tobramycin (TOB); however, studies suggest TOB cannot effectively inhibit biofilm formation. Using an NIH small compounds drug library approved for safe use in humans, we identified rifaximin (RFX), a semisynthetic, rifamycin family, nonsystemic antibiotic that inhibits alginate production and growth inP. aeruginosa. Inhibition of alginate production was further analyzed using the uronic acid carbazole assay and a promoter reporter assay that measures the transcription of the alginate biosynthetic operon. Compared to TOB, RFX significantly reduced alginate production in laboratory and CF sputum isolates ofP. aeruginosa. In addition, RFX showed a narrow range of MICs when measured with multidrug-resistant bacterial species of clinical relevance, synergistic activities with TOB or amikacin against clinical isolates, as well as reduction towardin vitropreformed biofilms. In C57BL/6 mice, penetration of nebulized TOB into the lungs was shown at a higher level than that of RFX. Further,in vivoassessment using a DBA/2 mouse lung infection model found increased survival rates with a single-dose treatment of nebulized RFX and decreasedP. aeruginosaPAO1 bioburden with a multiple-dose treatment of RFX plus TOB. In addition, mice treated with a single exposure to dimethyl sulfoxide (DMSO), a solvent that dissolves RFX, showed no apparent toxicity. In summary, RFX may be used to supplement TOB inhalation therapy to increase efficacy againstP. aeruginosabiofilm infections.

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