Ro 13-9904 and GR 20263, two new cephalosporins with broad-spectrum activity: an in vitro comparison with other B-actam antibiotics

1981 ◽  
Vol 7 (5) ◽  
pp. 515-520 ◽  
Author(s):  
A. M. Clarke ◽  
S. J. V. Zemcov
2020 ◽  
Vol 11 (12) ◽  
pp. 1379-1385
Author(s):  
R. Kirk ◽  
A. Ratcliffe ◽  
G. Noonan ◽  
M. Uosis-Martin ◽  
D. Lyth ◽  
...  

We disclose the discovery of REDX07965, a novel tricyclic topoisomerase inhibitor (NTTI) which has broad spectrum activity, favourable in vitro pharmacokinetic properties and selectivity versus human topoisomerase II.


2021 ◽  
Vol 17 (2) ◽  
pp. e1009110
Author(s):  
Laura I. Levi ◽  
Veronica V. Rezelj ◽  
Annabelle Henrion-Lacritick ◽  
Diana Erazo ◽  
J Boussier ◽  
...  

Defective viral genomes (DVGs) are truncated and/or rearranged viral genomes produced during virus replication. Described in many RNA virus families, some of them have interfering activity on their parental virus and/or strong immunostimulatory potential, and are being considered in antiviral approaches. Chikungunya virus (CHIKV) is an alphavirus transmitted by Aedes spp. that infected millions of humans in the last 15 years. Here, we describe the DVGs arising during CHIKV infection in vitro in mammalian and mosquito cells, and in vivo in experimentally infected Aedes aegypti mosquitoes. We combined experimental and computational approaches to select DVG candidates most likely to have inhibitory activity and showed that, indeed, they strongly interfere with CHIKV replication both in mammalian and mosquito cells. We further demonstrated that some DVGs present broad-spectrum activity, inhibiting several CHIKV strains and other alphaviruses. Finally, we showed that pre-treating Aedes aegypti with DVGs prevented viral dissemination in vivo.


2020 ◽  
Vol 65 (1) ◽  
pp. e01527-20
Author(s):  
Karen Marie Thyssen Astvad ◽  
Karin Meinike Jørgensen ◽  
Rasmus Krøger Hare ◽  
Raluca Datcu ◽  
Maiken Cavling Arendrup

ABSTRACTOlorofim is a novel antifungal drug in phase 2 trials. It has shown promising in vitro activity against various molds, except for Mucorales. Initially, we observed a broad range of EUCAST MICs for Aspergillus fumigatus. Here, we explored the MIC variability in more detail and prospectively investigated the susceptibility of contemporary clinical mold isolates, as population data are needed for future epidemiological cutoff (ECOFF) settings. Fifteen A. fumigatus isolates previously found with low/medium/high MICs (≤0.002 to 0.25 mg/liter) were tested repeatedly and EUCAST MICs read in a blinded fashion by three observers. pyrE, encoding the olorofim target enzyme dihydroorotate dehydrogenase (DHODH), was sequenced. A total of 1,423 mold isolates (10 Aspergillus species complexes [including 1,032 A. fumigatus isolates] and 105 other mold/dermatophyte isolates) were examined. Olorofim susceptibility (modal MIC, MIC50, MIC90, and wild-type upper limits [WT-ULs] [species complexes with ≥15 isolates]) was determined and compared to that of four comparators. MICs (mg/liter) were within two 2-fold dilutions (0.016 to 0.03) for 473/476 determinations. The MIC range spanned four dilutions (0.008 to 0.06). No significant pyrE mutations were found. Modal MIC/WT-UL97.5 (mg/liter) values were 0.03/0.06 (A. terreus and A. flavus), 0.06/0.125 (A. fumigatus and Trichophyton rubrum), and 0.06/0.25 (A. niger and A. nidulans). The MIC range for Scedosporium spp. was 0.008 to 0.25. Olorofim susceptibility was similar for azole-resistant and -susceptible isolates of A. fumigatus but reduced for A. montevidensis and A. chevalieri (MICs of >1). With experience, olorofim susceptibility testing is robust. The testing of isolates from our center showed uniform and broad-spectrum activity. Single-center WT-ULs are suggested.


2011 ◽  
Vol 55 (5) ◽  
pp. 2398-2402 ◽  
Author(s):  
Chau Minh Tran ◽  
Kaori Tanaka ◽  
Yuka Yamagishi ◽  
Takatsugu Goto ◽  
Hiroshige Mikamo ◽  
...  

ABSTRACTWe evaluated thein vitroantianaerobic activity of razupenem (SMP-601, PTZ601), a new parenterally administered carbapenem, against 70 reference strains and 323 clinical isolates. Razupenem exhibited broad-spectrum activity against anaerobes, inhibiting most of the reference strains when used at a concentration of ≤1 μg/ml. Furthermore, it exhibited strong activity, comparable to those of other carbapenems (meropenem and doripenem), against clinically isolated non-fragilis Bacteroidesspp. (MIC90s of 2 μg/ml), with MIC90values of 0.06, 0.03, and 0.5 μg/ml againstPrevotellaspp.,Porphyromonasspp., andFusobacteriumspp., respectively. Clinical isolates of anaerobic Gram-positive cocci,Eggerthellaspp., andClostridiumspp. were highly susceptible to razupenem (MIC90s, 0.03 to 1 μg/ml).


Viruses ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1665
Author(s):  
Irina Leneva ◽  
Nadezhda Kartashova ◽  
Artem Poromov ◽  
Anastasiia Gracheva ◽  
Ekaterina Korchevaya ◽  
...  

An escalating pandemic of the novel SARS-CoV-2 virus is impacting global health, and effective antivirals are needed. Umifenovir (Arbidol) is an indole-derivative molecule, licensed in Russia and China for prophylaxis and treatment of influenza and other respiratory viral infections. It has been shown that umifenovir has broad spectrum activity against different viruses. We evaluated the sensitivity of different coronaviruses, including the novel SARS-CoV-2 virus, to umifenovir using in vitro assays. Using a plaque assay, we revealed an antiviral effect of umifenovir against seasonal HCoV-229E and HCoV-OC43 coronaviruses in Vero E6 cells, with estimated 50% effective concentrations (EC50) of 10.0 ± 0.5 µM and 9.0 ± 0.4 µM, respectively. Umifenovir at 90 µM significantly suppressed plaque formation in CMK-AH-1 cells infected with SARS-CoV. Umifenovir also inhibited the replication of SARS-CoV-2 virus, with EC50 values ranging from 15.37 ± 3.6 to 28.0 ± 1.0 µM. In addition, 21–36 µM of umifenovir significantly suppressed SARS-CoV-2 virus titers (≥2 log TCID50/mL) in the first 24 h after infection. Repurposing of antiviral drugs is very helpful in fighting COVID-19. A safe, pan-antiviral drug such as umifenovir could be extremely beneficial in combating the early stages of a viral pandemic.


1978 ◽  
Vol 4 (5) ◽  
pp. 437-444 ◽  
Author(s):  
J. M. T. Hamilton-Miller ◽  
W. Bnumfitt ◽  
A. V. Reynolds

1997 ◽  
Vol 326 (1) ◽  
pp. 39-45 ◽  
Author(s):  
Eva J. HELMERHORST ◽  
Wim VAN 'T HOF ◽  
Enno C. I. VEERMAN ◽  
Ina SIMOONS-SMIT ◽  
Arie V. NIEUW AMERONGEN

Histatins are salivary histidine-rich cationic peptides, ranging from 7 to 38 amino acid residues in length, that exert a potent killing effect in vitro on Candida albicans. Starting from the C-terminal fungicidal domain of histatin 5 (residues 11–24, called dh-5) a number of substitution analogues were chemically synthesized to study the effect of amphipathicity of the peptide in helix conformation on candidacidal activity. Single substitutions in dh-5 at several positions did not have any effect on fungicidal activity. However, multi-site substituted analogues (dhvar1 and dhvar2) exhibited a 6-fold increased activity over dh-5. In addition, dhvar1 and dhvar2 inhibited the growth of the second most common yeast found in clinical isolates, Torulopsis glabrata, of oral- and non-oral pathogens such as Prevotella intermedia and Streptococcus mutans, and of a methicillin-resistant Staphylococcus aureus. In their broad-spectrum activity, dhvar1 and dhvar2 were comparable to magainins (PGLa and magainin 2), antimicrobial peptides of amphibian origin. Both the fungicidal and the haemolytic activities of dhvar1, dhvar2 and magainins increased at decreasing ionic strength.


2009 ◽  
Vol 53 (8) ◽  
pp. 3552-3560 ◽  
Author(s):  
Wolfgang Haas ◽  
Chris M. Pillar ◽  
Gary E. Zurenko ◽  
Jacqueline C. Lee ◽  
Lynne S. Brunner ◽  
...  

ABSTRACT The antibacterial spectrum of besifloxacin, a novel fluoroquinolone recently approved for treatment of ocular infections, was studied using 2,690 clinical isolates representing 40 species. Overall, besifloxacin was the most potent agent tested against gram-positive pathogens and anaerobes and was generally equivalent to comparator fluoroquinolones in activity against most gram-negative pathogens. Besifloxacin demonstrated potent, broad-spectrum activity, which was particularly notable against gram-positive and gram-negative isolates that were resistant to other fluoroquinolones and classes of antibacterial agents.


2020 ◽  
Vol 117 (4) ◽  
pp. 2122-2132 ◽  
Author(s):  
Evelyn M. Covés-Datson ◽  
Steven R. King ◽  
Maureen Legendre ◽  
Auroni Gupta ◽  
Susana M. Chan ◽  
...  

There is a strong need for a new broad-spectrum antiinfluenza therapeutic, as vaccination and existing treatments are only moderately effective. We previously engineered a lectin, H84T banana lectin (H84T), to retain broad-spectrum activity against multiple influenza strains, including pandemic and avian, while largely eliminating the potentially harmful mitogenicity of the parent compound. The amino acid mutation at position 84 from histidine to threonine minimizes the mitogenicity of the wild-type lectin while maintaining antiinfluenza activity in vitro. We now report that in a lethal mouse model H84T is indeed nonmitogenic, and both early and delayed therapeutic administration of H84T intraperitoneally are highly protective, as is H84T administered subcutaneously. Mechanistically, attachment, which we anticipated to be inhibited by H84T, was only somewhat decreased by the lectin. Instead, H84T is internalized into the late endosomal/lysosomal compartment and inhibits virus–endosome fusion. These studies reveal that H84T is efficacious against influenza virus in vivo, and that the loss of mitogenicity seen previously in tissue culture is also seen in vivo, underscoring the potential utility of H84T as a broad-spectrum antiinfluenza agent.


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