scholarly journals In Vivo Activity of the Pyrrolopyrazolyl-Substituted Oxazolidinone RWJ-416457

2009 ◽  
Vol 53 (5) ◽  
pp. 2028-2033 ◽  
Author(s):  
Jamese J. Hilliard ◽  
Jeffrey Fernandez ◽  
John Melton ◽  
Mark J. Macielag ◽  
Raul Goldschmidt ◽  
...  

ABSTRACT RWJ-416457 is an investigational pyrrolopyrazolyl-substituted oxazolidinone with activity against antibiotic-susceptible and -resistant gram-positive pathogens. Efficacies of RWJ-416457, linezolid, and vancomycin against methicillin-susceptible Staphylococcus aureus (MSSA) and community-associated methicillin-resistant S. aureus (CA-MRSA) in murine skin and systemic infections were compared, as were efficacies against Streptococcus pneumoniae in a lower respiratory infection. In staphylococcal systemic infections, RWJ-416457 was equipotent with to twofold more potent than linezolid, with 50% effective dose values ranging from 1.5 to 5 mg/kg of body weight/day. RWJ-416457 was two- to fourfold less potent than vancomycin against MSSA but up to fourfold more potent than vancomycin against CA-MRSA. In MSSA and CA-MRSA skin infections, RWJ-416457 demonstrated an efficacy similar to that of linezolid, reducing CFU/g skin approximately 1.0 log10 at all doses tested; vancomycin yielded greater reductions than the oxazolidinones, with decreases in CFU/g skin of 3 log10 (MSSA) and 2 log10 (CA-MRSA). In the pneumococcal model, RWJ-416457 was two- to fourfold more potent than linezolid. The free-drug area under the concentration-time curves at 24 h (fAUC24) were similar for RWJ-416457 and linezolid. The half-life of RWJ-416457 was up to threefold longer than that of linezolid for all routes of administration. The fAUC24/MIC ratio, the pharmacodynamic parameter considered predictive of oxazolidinone efficacy, was approximately twofold greater for RWJ-416457 than for linezolid. Since the fAUC values were similar for both compounds, the higher fAUC/MIC ratios of RWJ-416457 appear to result from its greater in vitro potency. These results demonstrate that RWJ-416457 is a promising new oxazolidinone with efficacy in S. aureus or S. pneumoniae mouse infection models.

1988 ◽  
Vol 1 (2) ◽  
pp. 187-217 ◽  
Author(s):  
R A Fromtling

Fungal infections are a major burden to the health and welfare of modern humans. They range from simply cosmetic, non-life-threatening skin infections to severe, systemic infections that may lead to significant debilitation or death. The selection of chemotherapeutic agents useful for the treatment of fungal infections is small. In this overview, a major chemical group with antifungal activity, the azole derivatives, is examined. Included are historical and state of the art information on the in vitro activity, experimental in vivo activity, mode of action, pharmacokinetics, clinical studies, and uses and adverse reactions of imidazoles currently marketed (clotrimazole, miconazole, econazole, ketoconazole, bifonazole, butoconazole, croconazole, fenticonazole, isoconazole, oxiconazole, sulconazole, and tioconazole) and under development (aliconazole and omoconazole), as well as triazoles currently marketed (terconazole) and under development (fluconazole, itraconazole, vibunazole, alteconazole, and ICI 195,739).


1996 ◽  
Vol 40 (10) ◽  
pp. 2237-2242 ◽  
Author(s):  
K Hata ◽  
J Kimura ◽  
H Miki ◽  
T Toyosawa ◽  
T Nakamura ◽  
...  

ER-30346 is a novel oral triazole with a broad spectrum of potent activity against a wide range of fungi. ER-30346, with MICs at which 90% of the strains tested are inhibited (MIC90s) ranging from 0.025 to 0.78 microgram/ml, was 4 to 32 times more active than itraconazole, fluconazole, and amphotericin B against Candida albicans, Candida parapsilosis, and Candida glabrata. Against Candida tropicalis, ER-30346, with an MIC90 of 12.5 micrograms/ml, was 2 to > 8 times more active than itraconazole and fluconazole, but was 16 times less active than amphotericin B. ER-30346 (MIC90, 0.78 microgram/ml) was four to eight times more active than fluconazole and amphotericin B and had activity comparable to that of itraconazole against Trichosporon beigelli. The MIC90s of ER-30346 were 0.10 microgram/ml for Cryptococcus neoformans and 0.39 microgram/ml for Aspergillus fumigatus. ER-30346 was 2 to 8 times more active than itraconazole and amphotericin B and 32 to > 256 times more active than fluconazole. ER-30346 also showed good activity against dermatophytes, with MICs ranging from 0.05 to 0.39 microgram/ml, and its activity was comparable to or 2 to 16 times higher than those of itraconazole and amphotericin B and > 32 times higher than that of fluconazole. In vivo activity was evaluated with systemic infections in mice. Against systemic candidiasis and cryptococcosis, ER-30346 was comparable in efficacy to fluconazole and was more effective than itraconazole. Of the drugs tested, ER-30346 was the most effective drug against systemic aspergillosis. We studied the levels of ER-30346 in mouse plasma. The maximum concentration of drug in plasma and the area under the concentration-time curve for ER-30346 showed good linearity over a range of doses from 2 to 40 mg/kg of body weight.


2009 ◽  
Vol 53 (10) ◽  
pp. 4525-4528 ◽  
Author(s):  
Xue-Fu You ◽  
Cong-Ran Li ◽  
Xin-Yi Yang ◽  
Min Yuan ◽  
Wei-Xin Zhang ◽  
...  

ABSTRACT Vertilmicin is a novel aminoglycoside antibiotic with potent activity against gram-negative and -positive bacteria in vitro. In this study, we further evaluated the efficacy of vertilmicin in vivo in systemic and local infection animal models. We demonstrated that vertilmicin had relatively high and broad-spectrum activities against mouse systemic infections caused by Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, and Enterococcus faecalis. The 50% effective doses of subcutaneously administered vertilmicin were 0.63 to 0.82 mg/kg, 0.18 to 0.29 mg/kg, 0.25 to 0.99 mg/kg, and 4.35 to 7.11 mg/kg against E. coli, K. pneumoniae, S. aureus, and E. faecalis infections, respectively. The therapeutic efficacy of vertilmicin was generally similar to that of netimicin, better than that of gentamicin in all the isolates tested, and better than that of verdamicin against E. coli 9612 and E. faecalis HH22 infections. The therapeutic efficacy of vertilmicin was further confirmed in local infection models of rabbit skin burn infection and mouse ascending urinary tract infection.


2003 ◽  
Vol 47 (8) ◽  
pp. 2507-2512 ◽  
Author(s):  
Masakatsu Tsuji ◽  
Morio Takema ◽  
Hideaki Miwa ◽  
Jingoro Shimada ◽  
Shogo Kuwahara

ABSTRACT The in vivo antibacterial activity of S-3578, a new parental cephalosporin, was compared with those of cefepime, ceftriaxone, ceftazidime, imipenem-cilastatin, and vancomycin. The efficacy of S-3578 against systemic infections caused by methicillin-resistant Staphylococcus aureus (MRSA) SR3637 (50% effective dose [ED50], 7.21 mg/kg of body weight) was almost the same as that of vancomycin. In contrast, cefepime and imipenem-cilastatin were less active against this pathogen (ED50s, >100 and >100 mg/kg, respectively). S-3578 was the most effective compound against penicillin-resistant Streptococcus pneumoniae SR20946 (ED50, 1.98 mg/kg). S-3578 (10 mg/kg) induced a significant reduction in the numbers of viable MRSA SR17764 and Pseudomonas aeruginosa SR10396 organisms in polymicrobial pulmonary infections. The therapeutic efficacy of S-3578 was more potent than that of the combination of vancomycin and ceftazidime. High levels of S-3578 were detected in plasma in vivo, and its efficacy against experimentally induced infections in mice caused by MRSA and P. aeruginosa reflected its potent in vitro activity. We conclude that S-3578 is a promising new cephalosporin for the treatment of infections caused by gram-positive and -negative bacteria, including MRSA and P. aeruginosa.


2016 ◽  
Vol 61 (2) ◽  
Author(s):  
Catharine C. Bulik ◽  
Ólanrewaju O. Okusanya ◽  
Elizabeth A. Lakota ◽  
Alan Forrest ◽  
Sujata M. Bhavnani ◽  
...  

ABSTRACT Gepotidacin (formerly called GSK2140944) is a novel triazaacenaphthylene bacterial topoisomerase inhibitor with in vitro activity against conventional and biothreat pathogens, including Staphylococcus aureus and Streptococcus pneumoniae. Using neutropenic murine thigh and lung infection models, the pharmacokinetics-pharmacodynamics (PK-PD) of gepotidacin against S. aureus and S. pneumoniae were characterized. Candidate models were fit to single-dose PK data from uninfected mice (for doses of 16 to 128 mg/kg of body weight given subcutaneously [s.c.]). Dose fractionation studies (1 isolate/organism; 2 to 512 mg/kg/day) and dose-ranging studies (5 isolates/organism; 2 to 2,048 mg/kg/day; MIC ranges of 0.5 to 2 mg/liter for S. aureus and 0.125 to 1 mg/liter for S. pneumoniae) were conducted. The presence of an in vivo postantibiotic effect (PAE) was also evaluated. Relationships between the change from baseline in log10 CFU at 24 h and the ratio of the free-drug plasma area under the concentration-time curve (AUC) to the MIC (AUC/MIC ratio), the ratio of the maximum concentration of drug in plasma (C max) to the MIC (C max/MIC ratio), and the percentage of a 24-h period that the drug concentration exceeded the MIC (%T>MIC) were evaluated using Hill-type models. Plasma and epithelial lining fluid (ELF) PK data were best fit by a four-compartment model with linear distributional clearances, a capacity-limited clearance, and a first-order absorption rate. The ELF penetration ratio in uninfected mice was 0.65. Since the growth of both organisms was poor in the murine lung infection model, lung efficacy data were not reported. As determined using the murine thigh infection model, the free-drug plasma AUC/MIC ratio was the PK-PD index most closely associated with efficacy (r 2 = 0.936 and 0.897 for S. aureus and S. pneumoniae, respectively). Median free-drug plasma AUC/MIC ratios of 13.4 and 58.9 for S. aureus, and 7.86 and 16.9 for S. pneumoniae, were associated with net bacterial stasis and a 1-log10 CFU reduction from baseline, respectively. Dose-independent PAE durations of 3.07 to 12.5 h and 5.25 to 8.46 h were demonstrated for S. aureus and S. pneumoniae, respectively.


2012 ◽  
Vol 56 (12) ◽  
pp. 6137-6146 ◽  
Author(s):  
Jared L. Crandon ◽  
Virna J. Schuck ◽  
Mary Anne Banevicius ◽  
Marie-Eve Beaudoin ◽  
Wright W. Nichols ◽  
...  

ABSTRACTThe combination of ceftazidime and avibactam possesses potent activity against resistant Gram-negative pathogens, includingPseudomonas aeruginosa. We compared the efficacies of human simulated doses of ceftazidime and ceftazidime-avibactam using a hollow-fiber system and neutropenic and immunocompetent murine thigh infection models. Twenty-seven clinicalP. aeruginosaisolates with ceftazidime MICs of 8 to 128 mg/liter and ceftazidime-avibactam MICs of 4 to 32 mg/liter were utilized in neutropenic mouse studies; 15 of the isolates were also evaluated in immunocompetent mice. Six isolates were studied in both the hollow-fiber system and the neutropenic mouse. In both systems, the free drug concentration-time profile seen in humans given 2 g of ceftazidime every 8 h (2-h infusion), with or without avibactam at 500 mg every 8 h (2-h infusion), was evaluated.In vivoactivity was pharmacodynamically predictable based on the MIC. Ceftazidime decreased bacterial densities by ≥0.5 log unit for 10/27 isolates, while ceftazidime-avibactam did so for 22/27 isolates. In immunocompetent animals, enhancements in activity were seen for both drugs, with ceftazidime achieving reductions of ≥0.3 log unit for 10/15 isolates, whereas ceftazidime-avibactam did so against all 15 isolates.In vitro, ceftazidime resulted in regrowth by 24 h against all isolates, while ceftazidime-avibactam achieved stasis or better against 4/7 isolates. Mutants with elevated ceftazidime-avibactam MICs appeared after 24 h from 3/7 isolates studiedin vitro; however, no resistant mutants were detectedin vivo. Against this highly ceftazidime-nonsusceptible population ofP. aeruginosa, treatment with human simulated doses of ceftazidime-avibactam resulted in pharmacodynamically predictable activity, particularlyin vivo, against isolates with MICs of ≤16 mg/liter, and this represents a potential new option to combat these difficult-to-treat pathogens.


2008 ◽  
Vol 52 (10) ◽  
pp. 3492-3496 ◽  
Author(s):  
W. A. Craig ◽  
D. R. Andes

ABSTRACT Ceftobiprole medocaril is the parenteral prodrug of ceftobiprole, a novel pyrrolidinone broad-spectrum cephalosporin with in vitro and in vivo bactericidal activities against methicillin-resistant Staphylococcus aureus (MRSA) and penicillin-resistant Streptococcus pneumoniae (PRSP). We have used murine thigh and lung infection models in neutropenic and normal mice to characterize the in vivo pharmacokinetic (PK)-pharmacodynamic (PD) activities of ceftobiprole against multiple strains of S. aureus (including MRSA), S. pneumoniae (including PRSP), and gram-negative bacilli. Serum levels of ceftobiprole following the administration of multiple doses were determined by a microbiological assay. In vivo bactericidal activities and postantibiotic effects (PAEs) of ceftobiprole against MRSA and PRSP strains were determined from serial CFU/thigh values following single doses of ceftobiprole (40 and 160 mg/kg of body weight). Dose fractionation studies were used to determine which PK-PD index correlated best with activity. Magnitudes of the PK-PD indices were calculated from MICs and PK parameters. A sigmoid dose-response model was used to estimate the dose (mg/kg/24 h) required to achieve a static and 2-log10 kill effects over 24 h. PK results showed area under the concentration-time curve/dose values of 1.8 to 2.8 and half-lives of 0.29 to 0.51 h. MICs ranged from 0.015 to 2 μg/ml. Ceftobiprole demonstrated time-dependent killing; its in vivo PAEs varied from 3.8 h to 4.8 h for MRSA and from 0 to 0.8 h for PRSP. The time above MIC (T > MIC) correlated best with efficacy for both MRSA and PRSP. The T > MIC values required for the static doses were significantly longer (P < 0.001) for Enterobacteriaceae (36 to 45%) than for S. aureus (14 to 28%) and S. pneumoniae (15 to 22%). The drug showed activities in the lung model similar to those in the thigh model. The presence of neutrophils significantly enhanced the activity of ceftobiprole against S. pneumoniae but only slightly against Klebsiella pneumoniae. Based on its PD profile, ceftobiprole is a promising new β-lactam agent with activity against gram-negative and gram-positive organisms including MRSA and PRSP.


2005 ◽  
Vol 49 (6) ◽  
pp. 2498-2500 ◽  
Author(s):  
Eun Jeong Yoon ◽  
Yeong Woo Jo ◽  
Sung Hak Choi ◽  
Tae Ho Lee ◽  
Jae Keol Rhee ◽  
...  

ABSTRACT In vitro and in vivo activities of DA-7867 were assessed against methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, and penicillin-resistant Streptococcus pneumoniae. All isolates were inhibited by DA-7867 at ≤0.78 μg/ml, a four-times-lower concentration than that of inhibition by linezolid. For murine infection models, DA-7867 also exhibited greater efficacy than linezolid against all isolates tested.


Nanomaterials ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 791 ◽  
Author(s):  
Ming-Hsiang Chang ◽  
Yu-Ping Hsiao ◽  
Chia-Yen Hsu ◽  
Ping-Shan Lai

Wound infection extends the duration of wound healing and also causes systemic infections such as sepsis, and, in severe cases, may lead to death. Early prevention of wound infection and its appropriate treatment are important. A photoreactive modified gelatin (GE-BTHE) was synthesized by gelatin and a conjugate formed from the 3,3′,4,4′-benzophenone tetracarboxylic dianhydride (BTDA) and the 2-hydroxyethyl methacrylate (HEMA). Herein, we investigated the photocurable polymer solution (GE-BTHE mixture) containing GE-BTHE, poly(ethylene glycol) diacrylate (PEGDA), chitosan, and methylene blue (MB), with antimicrobial functions and photodynamic antimicrobial chemotherapy for wound dressing. This photocurable polymer solution was found to have fast film-forming property attributed to the photochemical reaction between GE-BTHE and PEGDA, as well as the antibacterial activity in vitro attributed to the ingredients of chitosan and MB. Our in vivo results also demonstrated that untreated wounds after 3 days had the same scab level as the GE-BTHE mixture-treated wounds after 20 s of irradiation, which indicates that the irradiated GE-BTHE mixture can be quickly transferred into artificial scabs to protect wounds from an infection that can serve as a convenient excisional wound dressing with antibacterial efficacy. Therefore, it has the potential to treat nonhealing wounds, deep burns, diabetic ulcers and a variety of mucosal wounds.


2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
György Schneider ◽  
Nikolett Szentes ◽  
Marianna Horváth ◽  
Ágnes Dorn ◽  
Alysia Cox ◽  
...  

Escherichia (E.) coliK1 strains remain common causative agents of neonatal sepsis and meningitis. We have isolated a lytic bacteriophage (ΦIK1) againstE. colistrain IHE3034 and tested its specificityin vitro, as well as distribution and protective efficacyin vivo. The phage was shown to be specific to the K1 capsular polysaccharide. In the lethal murine model, a high level of protection was afforded by the phage with strict kinetics. A single dose of 1 x 108phage particles administered 10 and 60 minutes following the bacterial challenge elicited 100 % and 95 % survival, respectively. No mice could be rescued if phage administration occurred 3 hours postinfection. Tissue distribution surveys in the surviving mice revealed that the spleen was the primary organ in which accumulation of active ΦIK1 phages could be detected two weeks after phage administration. These results suggest that bacteriophages have potential as therapeutic agents in the control of systemic infections.


Sign in / Sign up

Export Citation Format

Share Document