scholarly journals Niclosamide Is Active In Vitro against Mycetoma Pathogens

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 4005
Author(s):  
Abdelhalim B. Mahmoud ◽  
Shereen Abd Algaffar ◽  
Wendy van de Sande ◽  
Sami Khalid ◽  
Marcel Kaiser ◽  
...  

Redox-active drugs are the mainstay of parasite chemotherapy. To assess their repurposing potential for eumycetoma, we have tested a set of nitroheterocycles and peroxides in vitro against two isolates of Madurella mycetomatis, the main causative agent of eumycetoma in Sudan. All the tested compounds were inactive except for niclosamide, which had minimal inhibitory concentrations of around 1 µg/mL. Further tests with niclosamide and niclosamide ethanolamine demonstrated in vitro activity not only against M. mycetomatis but also against Actinomadura spp., causative agents of actinomycetoma, with minimal inhibitory concentrations below 1 µg/mL. The experimental compound MMV665807, a related salicylanilide without a nitro group, was as active as niclosamide, indicating that the antimycetomal action of niclosamide is independent of its redox chemistry (which is in agreement with the complete lack of activity in all other nitroheterocyclic drugs tested). Based on these results, we propose to further evaluate the salicylanilides, niclosamidein particular, as drug repurposing candidates for mycetoma.

2021 ◽  
Vol 23 (3) ◽  
pp. 280-291
Author(s):  
Roman S. Kozlov ◽  
Ilya S. Azyzov ◽  
Andrey V. Dekhnich ◽  
Nataly V. Ivanchik ◽  
Alexey Yu. Kuzmenkov ◽  
...  

Objective. To evaluate in vitro activity of biapenem and other clinically available carbapenems against Russian clinical isolates of Enterobacterales, Pseudomonas aeruginosa и Acinetobacter spp., including isolates with acquired fermentative mechanisms of resistance to β-lactams. Materials and Methods. A total of 3139 Enterobacterales isolates, 793 P. aeruginosa isolates and 634 Acinetobacter spp. isolates from hospitalized patients in 63 hospitals from 35 Russian cities were included in the study during 2018-2019. Minimal inhibitory concentrations (MIC) for biapenem and other antimicrobials were determined in accordance with ISO 20776-1:2006. Carbapenemases genes were detected by commercially available real-time PCR kits AmpliSens® MDR KPC/OXA-48-FL and AmpliSens® MDR MBL-FL (Central Research Institute of Epidemiology, Russia). Data analysis and reporting was performed using AMRcloud online platform (www.amrcloud.net). Results. For all tested Escherichia coli isolates MIC50/90 were 0.06/0.125 mg/l for biapenem, 0.125⁄0.25 mg/l for imipenem, and 0.06/0.06 mg/l for meropenem. When MIC50/90 for ertapenem (0.015/0.125 mg/l for all isolates tested) were comparable to those of biapenem, a greater number of nosocomial E. coli isolates had MIC >4 mg/l for ertapenem (3.6%) than for biapenem (2.6%). MIC50/90 of Klebsiella pneumoniae for biapenem were 0.5⁄16 mg/l, for both imipenem and meropenem – 0.5⁄32 mg/l, for ertapenem – 2⁄32 mg/l. Resistance to oxyimino-β-lactams had no significant influence on activity of biapenem against Enterobacterales isolates. For 321 carbapenemase-producing K. pneumoniae isolates (ОХА-48 – 63.9%, NDM – 27.7%) biapenem has shown no advantages over imipenem and meropenem. МПК50/90 for nosocomial and community-acquired P. aeruginosa isolates were 8⁄64 mg/l and 0,5⁄16 mg/l for biapenem, 8⁄128 mg/l and 1⁄16 mg/l – for imipenem, 16⁄64 mg/l and 0,5⁄32 mg/l – for meropenem. All carbapenems, including biapenem, had very low in vitro activity against carbapenemaseproducing P. aeruginosa isolates. МПК50/90 of Acinetobacter spp. were 64⁄128 mg/l for biapenem, 64⁄128 mg/l – for imipenem, and 128⁄128 mg/l – for meropenem. Conclusions. According to the MIC distributions and MICs50/90 values independently of the presence of fermentative mechanisms of resistance to β-lactams, in vitro activity of biapenem against Russian clinical isolates of Enterobacterales, P. aeruginosa and Acinetobacter spp. was comparable to those of imipenem and meropenem.


2004 ◽  
Vol 48 (5) ◽  
pp. 1912-1915 ◽  
Author(s):  
Zekaver Odabasi ◽  
Victor L. Paetznick ◽  
Jose R. Rodriguez ◽  
Enuo Chen ◽  
Luis Ostrosky-Zeichner

ABSTRACT In this study, we evaluated the in vitro activity of anidulafungin against selected mold isolates. Anidulafungin showed promising activity against Bipolaris spicifera, Exophiala jeanselmei, Fonsecaea pedrosoi, Madurella mycetomatis, Penicillium marneffei, Phialophora verrucosa, Pseudallescheria boydii, Sporothrix schenckii, and Wangiella dermatitidis.


Antibiotics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 696
Author(s):  
Lara U. Szabó ◽  
Marcel Kaiser ◽  
Pascal Mäser ◽  
Thomas J. Schmidt

Malaria and human African trypanosomiasis (HAT; sleeping sickness) are life-threatening tropical diseases caused by protozoan parasites. Due to limited therapeutic options, there is a compelling need for new antiprotozoal agents. In a previous study, O-tigloylcyclovirobuxeine-B was recovered from a B. sempervirens L. (common box; Buxaceae) leaf extract by bioactivity-guided isolation. This nor-cycloartane alkaloid was identified as possessing strong and selective in vitro activity against the causative agent of malaria tropica, Plasmodium falciparum (Pf). The purpose of this study is the isolation of additional alkaloids from B. sempervirens L. to search for further related compounds with strong antiprotozoal activity. In conclusion, 25 alkaloids were obtained from B. sempervirens L., including eight new natural products and one compound first described for this plant. The structure elucidation was accomplished by UHPLC/+ESI-QqTOF-MS/MS and NMR spectroscopy. The isolated alkaloids were tested against Pf and Trypanosoma brucei rhodesiense (Tbr), the causative agent of East African sleeping sickness. To assess their selectivity, cytotoxicity against mammalian cells (L6 cell line) was tested as well. Several of the compounds displayed promising in vitro activity against the pathogens in a sub-micromolar range with concurrent high selectivity indices (SI). Consequently, various alkaloids from B. sempervirens L. have the potential to serve as a novel antiprotozoal lead structure.


1981 ◽  
Vol 9 (3) ◽  
pp. 168-176 ◽  
Author(s):  
W Eugene Sanders ◽  
Christine C Sanders

The in vitro activity of sisomicin against Pseudomonas is two- to eight-fold greater then gentamicin or amikacin, and similar to tobramycin. Minimal inhibitory concentrations of sisomicin are usually <1.0 μg/ml. Sisomicin interacts synergistically with a variety of penicillins against many Pseudomonas, including strains resistant to gentamicin. The degree of cross-resistance between sisomicin and other aminoglycosides varies depending upon mechanism. Many strains with inactivating enzymes are resistant to sisomicin, gentamicin and tobramycin. However, due to high intrinsic potency, sisomicin is active against many strains that are resistant to other aminoglycosides as a result of impermeability. Thus sisomicin is active against 4% to 66% of strains resistant to gentamicin, tobramycin or amikacin. The ability of sisomicin to protect animals from fatal Pseudomonas infections has been assessed in 29 paired tests with tobramycin and 36 paired tests with gentamicin. The dose of sisomicin in mg/kg required to protect 50% of animals from death is, on average, 1.5 times lower than tobramycin and 3.1 times lower than gentamicin. Sisomicin also interacts synergistically with carbenicillin or ticarcillin in treatment of experimental infections in animals. The human pharmacology of sisomicin is similar to gentamicin. Rates of adverse reactions to sisomicin are comparable to those seen with gentamicin or tobramycin. Clinical trials have shown sisomicin to be as effective, and in some instances more effective, than gentamicin, tobramycin, or amikacin. In several studies, the efficacy of sisomicin, administered in lower doses than gentamicin, was equal to or greater than gentamicin. Infections caused by gentamicin-resistant Pseudomonas have responded to sisomicin. Also, several patients who failed to respond to either gentamicin or tobramycin have been successfully treated with sisomicin. In view of its high intrinsic potency both in vitro and in vivo, sisomicin may become a preferred agent for treatment of serious Pseudomonas infections due to sensitive strains.


2018 ◽  
Vol 20 (3) ◽  
pp. 192-197
Author(s):  
Natalya N. Dekhnich ◽  
Nataly V. Ivanchik ◽  
Roman S. Kozlov

Objective. Compare the in vitro activity of clarithromycin, erythromycin, azithromycin and josamycin against the collection of H. pylori strains isolated in 2010–2017 in Smolensk. Materials and Methods. H. pylori strains were collected prospectively from biopsy specimens of the gastric mucosa. Antimicrobial susceptibility testing of H. pylori was performed by the agar dilution method. Interpretation of the results of the susceptibility determination for clarithromycin was carried out in accordance with the recommendations of EUCAST (v 8.0) 2018. The resistance breakpoints for erythromycin, azithromycin, and josamycin were all set at ≥1.0 mg/L. For comparison of the results, the value of the minimal inhibitory concentrations of the tested antibiotic inhibiting the growth of 50% (MIC50) and 90% (MIC90) of H. pylori strains was used. Results. A total of 276 H. pylori strains were tested. 90% of the MIC values of clarithromycin were in the range from 0.015 to 0.125 mg/l. The percentages of resistance were as follows: clarithromycin 5.1%, azithromycin 7.5%, erythromycin 8%, josamycin 23.2%. Clarithromycin demonstrated significantly higher activity in suppressing the growth of H. pylori strains than azithromycin, erythromycin, and josamycin. Conclusions. Among the tested macrolide antibiotics maximal anti-H. pylori activity in vitro was observed in clarithromycin.


Planta Medica ◽  
2012 ◽  
Vol 78 (05) ◽  
Author(s):  
A Husni ◽  
S Ross ◽  
O Dale ◽  
C Gemelli ◽  
G Ma ◽  
...  

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