Browsing
     by title


0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

or enter first few letters:   
OK
Full Text
Peer Reviewed
See detailAntimalarial Activities of Alkyl Cyclohexenone Derivatives Isolated from the Leaves of Poupartia borbonica
Ledoux, Allison ULiege; St-Gelais, Alexis; Cieckiewicz, Ewa ULiege et al

in Journal of Natural Products (2017), 80(6), 1750-1757

Bioactivity-guided fractionation of the ethyl acetate extract of the leaves of Poupartia borbonica led to the isolation of three new alkyl cyclohexenone derivatives 1−3, and named Poupartone A−C. The ... [more ▼]

Bioactivity-guided fractionation of the ethyl acetate extract of the leaves of Poupartia borbonica led to the isolation of three new alkyl cyclohexenone derivatives 1−3, and named Poupartone A−C. The structures of the new compounds were elucidated by 1D and 2D NMR spectroscopic data analysis and MS, whereas calculated and experimental ECD spectra were used to define the absolute configurations. These compounds were active against 3D7 and W2 Plasmodium falciparum strains with IC50 values between 0.55 and 1.81 μM. In vitro cytotoxicity against WI38 human fibroblasts and the human cervical cancer cell line HeLa (WST-1 assay) showed that these compounds were also cytotoxic, but no hemolytic activity was observed for the extract and pure compounds. An in vivo antimalarial assay was performed on the major cyclohexenone using P. berghei-infected mice at a dose of 15 mg/kg/day ip. The assay revealed growth inhibition of 59.1 and 69.5% at days 5 and 7 postinfection, respectively, although some toxicity was observed. Zebrafish larvae were used as a model to determine the type of toxicity, and the results showed cardiac toxicity. The methanol extract was also studied, and it displayed moderate antiplasmodial properties in vitro. This extract contained the known flavonoids, quercetin, 3′-O-hydroxysulfonylquercetin, quercitrin, and isoquercitrin as well as ellagic acid, which showed high to low activity against the 3D7 P. falciparum strain. [less ▲]

Detailed reference viewed: 26 (14 ULiège)
Full Text
Peer Reviewed
See detailAntimalarial Activity of Cryptolepine and some otrher Anhydronium Bases
Wright, C. W.; Phillipson, J. D.; Awe, S. O. et al

in Phytotherapy Research (1996), 10

Eight naturally occurring anhydronium bases and the synthetic quaternary compound Nb-methylharmalane were tested against Plasmodium falciparun (strain K1) in vitro. Cryptolepine was found to have similar ... [more ▼]

Eight naturally occurring anhydronium bases and the synthetic quaternary compound Nb-methylharmalane were tested against Plasmodium falciparun (strain K1) in vitro. Cryptolepine was found to have similar activity to that of chloroquine but alstonine, 5,6-dihydroflavopereirine, matadine, Nb-methylharmalane, melinonine F, normelinonine F, strychnoxanthine and serpentine were found to have little activity. Cryptolepine, given orally to mice infected with Plasmodium berghei berghei was found to have moderate antimalarial activity; parasitemia was suppressed by 80% at 50 mg/kg/day. [less ▲]

Detailed reference viewed: 35 (3 ULiège)
Full Text
Peer Reviewed
See detailAntimalarial compounds isolated from plants used in traditional medicine.
Bero, Joanne; Frederich, Michel ULiege; Quetin-Leclercq, Joelle

in Journal of Pharmacy & Pharmacology (2009), 61(11), 1401-33

OBJECTIVES: This review covers the compounds with antiplasmodial activity isolated from plants published from 2005 to the end of 2008, organized according to their phytochemical classes. Details are given ... [more ▼]

OBJECTIVES: This review covers the compounds with antiplasmodial activity isolated from plants published from 2005 to the end of 2008, organized according to their phytochemical classes. Details are given for substances with IC50 values < or = 11 microm. KEY FINDINGS: Malaria is a major parasitic disease in many tropical and subtropical regions and is responsible for more than 1 million deaths each year in Africa. The rapid spread of resistance encourages the search for new active compounds. Nature and particularly plants used in traditional medicine are a potential source of new antimalarial drugs as they contain molecules with a great variety of structures and pharmacological activities. SUMMARY: A large number of antimalarial compounds with a wide variety of structures have been isolated from plants and can play a role in the development of new antimalarial drugs. Ethnopharmacological approaches appear to be a promising way to find plant metabolites that could be used as templates for designing new derivatives with improved properties. [less ▲]

Detailed reference viewed: 131 (6 ULiège)
Full Text
Peer Reviewed
See detailAntimicrobial activities of commercial essential oils and their components against food-borne pathogens and food spoilage bacteria.
Mith, Hasika; Dure, Remi; Delcenserie, Véronique ULiege et al

in Food science & nutrition (2014), 2(4), 403-16

This study was undertaken to determine the in vitro antimicrobial activities of 15 commercial essential oils and their main components in order to pre-select candidates for potential application in highly ... [more ▼]

This study was undertaken to determine the in vitro antimicrobial activities of 15 commercial essential oils and their main components in order to pre-select candidates for potential application in highly perishable food preservation. The antibacterial effects against food-borne pathogenic bacteria (Listeria monocytogenes, Salmonella Typhimurium, and enterohemorrhagic Escherichia coli O157:H7) and food spoilage bacteria (Brochothrix thermosphacta and Pseudomonas fluorescens) were tested using paper disk diffusion method, followed by determination of minimum inhibitory (MIC) and bactericidal (MBC) concentrations. Most of the tested essential oils exhibited antimicrobial activity against all tested bacteria, except galangal oil. The essential oils of cinnamon, oregano, and thyme showed strong antimicrobial activities with MIC >/= 0.125 muL/mL and MBC >/= 0.25 muL/mL. Among tested bacteria, P. fluorescens was the most resistant to selected essential oils with MICs and MBCs of 1 muL/mL. The results suggest that the activity of the essential oils of cinnamon, oregano, thyme, and clove can be attributed to the existence mostly of cinnamaldehyde, carvacrol, thymol, and eugenol, which appear to possess similar activities against all the tested bacteria. These materials could be served as an important natural alternative to prevent bacterial growth in food products. [less ▲]

Detailed reference viewed: 60 (9 ULiège)
Full Text
See detailAntimicrobial activities of key intermediate plant oxylipins
Deboever, Estelle ULiege

Conference (2017, June 28)

Nowadays, biopesticides have emerged as a main alternative to conventional agriculture. In this context, plant oxylipins, a vast and diverse family of secondary metabolites originated from polyunsaturated ... [more ▼]

Nowadays, biopesticides have emerged as a main alternative to conventional agriculture. In this context, plant oxylipins, a vast and diverse family of secondary metabolites originated from polyunsaturated fatty acids (PUFAs), appear to be crucial agents in plant defense mechanisms. Among plant oxylipins, the 13-hydroperoxy oxylipins (13-HPO) constitute key intermediate oxylipins (KIOs) as they can be converted into jasmonic acid, OPDA, dn-OPDA or traumatic acid, well-characterized components involved in plant resistance mechanisms. Their presumed functions include direct antimicrobial effect, stimulation of plant defense gene expression, and/or regulation of plant cell death. However, the precise contribution of each KIOs to plant defense remains essentially unknown. In this work, we focus on two h13-HPO, the 13(S)-hydroperoxy-octadecadienoic acid (13-HPOD) and the 13(S)-hydroperoxy-octadecatrienoic acid (13-HPOT). In vitro growth inhibition assays were performed to investigate the direct antimicrobial activities against 7 pathogens of agronomic interest including bacteria, oomycetes and fungi. This study showed unambiguously that 13-HPO are able to hinder growth of some plant microbial pathogens, generally with a higher efficacity for 13-HPOT. In order to get a better insight into their mechanism of action, a complementary in silico and experimental biophysical approach was applied. Biomimetic pathogen plasma membranes are used to study the mechanism at the molecular level. Slight conformational differences may have significant impacts on their ability to interact with pathogens lipids and plasma membranes. [less ▲]

Detailed reference viewed: 32 (1 ULiège)
Full Text
Peer Reviewed
See detailAntimicrobial activity against gram negative bacilli from Yaounde Central Hospital, Cameroon
Gangoue Pieboji, Joseph ULiege; Koulla-Shiro, S.; Ngassam, P. et al

in African Health Sciences (2006), 6(4), 232-5

BACKGROUND: Antimicrobial resistance among bacteria pathogens is a world-wide issue. The antimicrobial susceptibility patterns of common pathogenic bacteria are essential to guide empirical and pathogen ... [more ▼]

BACKGROUND: Antimicrobial resistance among bacteria pathogens is a world-wide issue. The antimicrobial susceptibility patterns of common pathogenic bacteria are essential to guide empirical and pathogen-specific therapy; unfortunately, these data are scarse in Cameroon. OBJECTIVE: To determine the antimicrobial susceptibility patterns of Gram-negative bacilli isolated in Yaounde Central Hospital Laboratory of Bacteriology. METHODS: Gram-negative bacilli isolates (n = 505), obtained from a wide range of clinical specimens (urine, pus and blood) in Yaounde Central Hospital Laboratory of Bacteriology between March 1995 and April 1998, were evaluated for resistance to antibiotics (amoxicillin, amoxicillin/clavulanate, piperacillin, cefazolin, cefoxitin, cefotaxime, ceftazidime, aztreonam, imipenem, gentamicin, tobramicin, ofloxacin and trimethoprim/sulfamethoxazole) by the Kirby-Bauer disk diffusion method. RESULTS: High rates of resistance were found in most of the bacteria studied. Resistance to all isolates was mostly observed for amoxicillin (87%), piperacillin (74%) and trimethoprim/sulfamethoxazole (73%). Susceptibilities to third generation cephalosporins (cefotaxime, ceftazidime) and monobactame (aztreonam) were = 91% for Escherichia coli, = 71% for Klebsiella spp., = 98% for Proteus mirabilis, = 50% for Enterobacter spp. and Citrobacter spp. Pseudomonas aeruginosa was less susceptible to cefotaxime (2%) and aztreonam (33%), and highly susceptible to ceftazidime (72%) whereas Acinetobacter baumannii was highly resistant to aztreonam (100%), to cefotaxime (96%) and cetazidime (62%). Imipenem (98%) was the most active antibiotic followed by the ofloxacine (88%). Susceptibility of all isolates to gentamicin was 67%. CONCLUSION: These results indicate that surveillance to antimicrobial resistance in Cameroon is necessary to monitor microbial trends, antimicrobial resistance pattern, and provide information for choosing empirical or direct therapy to physicians. [less ▲]

Detailed reference viewed: 27 (1 ULiège)
Peer Reviewed
See detailAntimicrobial activity of 5,6-dihydrobenzo-[a]-carbazoles.
Pappa, H.; Segall, A.; Pizzorno, M. T. et al

in Farmaco (Societa chimica italiana : 1989) (1994), 49(5), 333-6

A new series of 5,6-dihydrobenzo[a]carbazoles was synthesized, some showing good antibacterial activity. The presence of a dialkylamino ethyl chain on the 2-, 3- or 4-O-substituent seems to be critical ... [more ▼]

A new series of 5,6-dihydrobenzo[a]carbazoles was synthesized, some showing good antibacterial activity. The presence of a dialkylamino ethyl chain on the 2-, 3- or 4-O-substituent seems to be critical for such activity. [less ▲]

Detailed reference viewed: 14 (1 ULiège)
Full Text
Peer Reviewed
See detailAntimicrobial Activity of Bacillus amyloliquefaciens ANT1 Toward Pathogenic Bacteria and Mold: Effects on Biofilm Formation
Arguelles Arias, Anthony ULiege; Nastro, Rosa Anna; Ongena, Marc ULiege et al

in Probiotics and Antimicrobial Proteins (2013)

Detailed reference viewed: 32 (5 ULiège)
Full Text
Peer Reviewed
See detailAntimicrobial Activity of Bacillus amyloliquefaciens ANT1 Toward Pathogenic Bacteria and Mold: Effects on Biofilm Formation
Nastro, R. A.; Arguelles-Arias, A.; Ongena, Marc ULiege et al

in Probiotics and Antimicrobial Proteins (2013), 5

The intensive use and misuse of antibiotics over the last decades have generated a strong selective pressure for the emergence of multi-resistant strains and nosocomial infections. Biofilm has been ... [more ▼]

The intensive use and misuse of antibiotics over the last decades have generated a strong selective pressure for the emergence of multi-resistant strains and nosocomial infections. Biofilm has been demonstrated as a key parameter in spreading infections, especially in hospitals and healthcare units. Therefore, the development of novel anti-biofilm drugs is actually of the upmost importance. Here, the antimicrobial and antibiofilm activities toward pathogenic microorganisms of a set of non-ribosomal synthesized peptides and polyketides isolated from Bacillus amyloliquefaciens ANT1 culture supernatant are presented. © 2013 Springer Science+Business Media New York. [less ▲]

Detailed reference viewed: 54 (8 ULiège)
Full Text
Peer Reviewed
See detailAntimicrobial activity of polyestyrene particles coated by photo-crooslinked block copolymers containing a biocidal polymethacrylate block
Lenoir, Sandrine ULiege; Pagnoulle, Christophe; Detrembleur, Christophe ULiege et al

in e-Polymers (2005), 74

A commercially available poly(ethylene-co-butylene) copolymer, end-capped by a short polyisoprene block and a hydroxyl group (PI-b-PEB-OH), has been derivatized into a macroinitiator for atom transfer ... [more ▼]

A commercially available poly(ethylene-co-butylene) copolymer, end-capped by a short polyisoprene block and a hydroxyl group (PI-b-PEB-OH), has been derivatized into a macroinitiator for atom transfer radical polymerization (ATRP) by esterification of the hydroxyl end-group by an activated bromide-containing acyl bromide. Two types of triblock copolymers, Pl-b-PEB-b-poly(dimethylaminoethyl methacrylate) (PDMAEMA) and Pl-b-PEB-b-poly[2-(tert-butylamino)ethyl methacrylate] (PTBAEMA), have been synthesized and used to coat polystyrene particles. These coatings have been permanently immobilized by UV cross-linking of the isoprene units. They exhibit a biocidal activity against Gram-negative bacteria either intrinsically in case of the PTBAEMA block or upon quaternization of the PDMAEMA block by octyl bromide. The antimicrobial activity is directly related to the concentration of coated PS particles in the medium. [less ▲]

Detailed reference viewed: 144 (6 ULiège)
Full Text
Peer Reviewed
See detailAntimicrobial and molecular analysis of Salmonella serovar Livingstone strains isolated from humans in Tunisia and Belgium
Guedda, Intissar; Taminiau, Bernard ULiege; Ferjani, Asma et al

in Journal of Infection in Developing Countries [=JIDC] (2014), 8

Introduction: Salmonella Livingstone is one of the most common serotypes responsible for nosocomial outbreaks in Tunisia. In this study, 42 isolates of Salmonella Livingstone were analyzed. Most of these ... [more ▼]

Introduction: Salmonella Livingstone is one of the most common serotypes responsible for nosocomial outbreaks in Tunisia. In this study, 42 isolates of Salmonella Livingstone were analyzed. Most of these were isolated from humans (31 strains from Tunisia and 9 strains from Belgium) and 2 isolates came from food products (beef and pork). Methodology: All strains were characterized by antibiogram, multilocus sequence typing (MLST), and virulotyping. This last technique was carried out by simple PCR of five chromosomal genes (agfA, hin/H2, iroB, phoP/Q, and slyA) and two plasmid genes (spvA and spvC). Results: All Tunisian strains were resistant to amoxicillin, amoxicillin-clavulanic acid, ticarcillin, cefalotin, gentamicin, and kanamycin. They were also resistant to third-generation cephalosporin antibiotics (cefotaxim and ceftazidim). Belgian isolates were susceptible to all antibiotics tested. Further to MLST analyses, Tunisian strains belonged to the same sequence type, ST543. For Belgian isolates, eight strains had a ST543 profile, two strains had a ST638 profile, and one strain had a ST457 profile. Analyses of the virulence gene contents showed that strains isolated in different years and from different origins had the same virulence profile. These carried all five chromosomal genes and lacked plasmid-located virulence genes spvA and spvC. Conclusions: A combination of different typing methods showed that the majority of Belgian strains and all Tunisian strains were closely related; they belonged to the same sequence type (ST543) and had the same virulence profile, but different antibiotic resistance profiles depended on the country of origin. [less ▲]

Detailed reference viewed: 29 (2 ULiège)
Full Text
See detailAntimicrobial Effects of Bifidobacteria from Human and Animal Origin
Delcenserie, Véronique ULiege

Scientific conference (2015)

Detailed reference viewed: 14 (1 ULiège)
Full Text
Peer Reviewed
See detailAntimicrobial potential of probiotic or potentially probiotic lactic acid bacteria, the first results of the international European research project PROPATH of the PROEUHEALTH cluster
De Vuyst, L.; Lefteris, M.; Lazlo, A. et al

in Microbial Ecology in Health & Disease (2004), 16

The EU-funded PROPATH project addresses the important health issue of prevention of gastrointestinal disorders through probiotics and prebiotics. Seven European laboratories are co-operating in this ... [more ▼]

The EU-funded PROPATH project addresses the important health issue of prevention of gastrointestinal disorders through probiotics and prebiotics. Seven European laboratories are co-operating in this project, which aims to isolate and characterize the relevant antimicrobial agents to combat Gram-negative bacteria including Helicobacter pylori and Salmonella enterica serovar Typhimurium. In this paper, the first results on the screening for probiotic or potentially probiotic lactobacilli that exhibit antimicrobial activity towards these Gram-negative pathogenic bacteria are presented. Spot-on-lawn assays, well-diffusion assays and time-kill studies were performed among the lactic acid bacteria strains that were either collected from fermented foods and faeces (breast-fed babies, infants and animals) or isolated from commercial products to investigate whether any of the collected strains were inhibiting growth of or were killing certain indicator bacteria. Strains inhibiting the gastrointestinal pathogens mentioned above were found. Evidence has been obtained that compounds different from organic acids are produced. [less ▲]

Detailed reference viewed: 207 (2 ULiège)
Full Text
Peer Reviewed
See detailAntimicrobial properties of Pseudomonas strains producing the antibiotic mupirocin
Matthijs, S.; Vander Wauven, C.; Cornu, B. et al

in Research in Microbiology (2014), 165

Detailed reference viewed: 18 (1 ULiège)
See detailAntimicrobial resistance in Salmonella strains isolated during the zoonosis monitoring in Belgian slaughterhouses, meat plants and retail shops in 2002
Dierick, K.; Verloo, D.; Ghafir, Y. et al

Poster (2003, June 19)

Detailed reference viewed: 6 (0 ULiège)
See detailAntimicrobial resistance in Salmonella strains isolated during the zoonosis monitoring in slaughterhouses, meat plants and retail shops in 2001
Dierick, K.; Wybo, I.; Jouret, M. et al

Poster (2002, June 20)

Detailed reference viewed: 9 (0 ULiège)
Full Text
Peer Reviewed
See detailAntimicrobial Resistance in the food chain: a review
Verraes, Claire; Van Boxtael, Sigrid; Van Meervenne, Eva et al

in International Journal of Environmental Research and Public Health (2013), 10

Antimicrobial resistant zoonotic pathogens present on food constitute a direct risk to public health. Antimicrobial resistance genes in commensal or pathogenic strains form an indirect risk to public ... [more ▼]

Antimicrobial resistant zoonotic pathogens present on food constitute a direct risk to public health. Antimicrobial resistance genes in commensal or pathogenic strains form an indirect risk to public health, as they increase the gene pool from which pathogenic bacteria can pick up resistance traits. Food can be contaminated with antimicrobial resistant bacteria and/or antimicrobial resistance genes in several ways. A first way is the presence of antibiotic resistant bacteria on food selected by the use of antibiotics during agricultural production. A second route is the possible presence of resistance genes in bacteria that are intentionally added during the processing of food (starter cultures, probiotics, bioconserving microorganisms and bacteriophages). A last way is through cross-contamination with antimicrobial resistant bacteria during food processing. Raw food products can be consumed without having undergone prior processing or preservation and therefore hold a substantial risk for transfer of antimicrobial resistance to humans, as the eventually present resistant bacteria are not killed. As a consequence, transfer of antimicrobial resistance genes between bacteria after ingestion by humans may occur. Under minimal processing or preservation treatment conditions, sublethally damaged or stressed cells can be maintained in the food, inducing antimicrobial resistance build-up and enhancing the risk of resistance transfer. Food processes that kill bacteria in food products, decrease the risk of transmission of antimicrobial resistance. [less ▲]

Detailed reference viewed: 218 (17 ULiège)
Full Text
See detailAntimicrobial susceptibilities of Campylobacter strains isolated from food animals
Van Looveren, M.; Daube, Georges ULiege; De Zutter, L. et al

Poster (1999, September)

Detailed reference viewed: 5 (0 ULiège)
Full Text
Peer Reviewed
See detailAntimicrobial Susceptibilities of recent clinical isolates of group B streptococci agalactiae from Belgium
MELIN, Pierrette ULiege; Maquet, Julie; Rodriguez Cuns, Grisel et al

in American Society of Microbiology (Ed.) Program and Abstracts of the 43rd Intersciences Conference on Antimicrobial Agents and Chemotherapy (2003, September)

Background: : GBS cause severe infections in neonates, pregnant women and other adults. Empiric therapy is usually started before susceptibility results are available. Early neonatal diseases can be ... [more ▼]

Background: : GBS cause severe infections in neonates, pregnant women and other adults. Empiric therapy is usually started before susceptibility results are available. Early neonatal diseases can be prevented with intrapartum antibiotic prophylaxis based on accurate susceptibility surveillance data. A previous Belgian study showed an increase of 3 to 10 % R to erythromycin (EM) through the 1990s. Methods: 187 GBS isolates consecutively received at the reference laboratory between 2001 to March 2003 were from 73 neonates (52 early-onset and 21 late-onset diseases), 52 adults and 62 from pregnant women’s vagina. MICs of penicillin (PG), EM, clindamycin (CM) and gentamicin (GM) were determined with Etest. PG MBCs were also determined by inactivating the drug in MIC plates using betalactamase. EM resistant (R) isolates were tested by the CM + EM double disk to determine macrolide R phenotypes. Results: All strains were susceptible (S) to PG and no tolerance was observed with MBCs falling within 2 dilutions of MICs. 19.2% of isolates were R to EM, with significantly more R isolates from adults (30.8%; p <0.01) and serotype V (46.8%; p <0,001). 80% had the MLSB phenotype (R to EM and CM), 16 were constitutive and 12 inducible. The M phenotype (R to EM and S to CM) was seen in 7 (20%) of isolates. Less than 10% of isolates were inhibited by GM MIC of <=64 mg/L, 83.6% by 128-256 mg/L and 2.9% by >/=512 mg/L. Non typable strains were more R to GM (p <0.01). Conclusions: 1) PG remained active against all isolates and no tolerance was seen. 2) Prevalence of R to macrolides had increased since 1999, particularly in adult isolates and serotype V. 3) Intermediate to high level R to GM was seen and potential synergy of PG + GM should be investigated. 4) R surveillance is mandatory to guide prophylaxis and treatment of serious GBS infections. [less ▲]

Detailed reference viewed: 32 (4 ULiège)
Full Text
See detailAntimicrobial susceptibilities of Salmonella strains isolated from food animals
Van Looveren, M.; Daube, Georges ULiege; De Zutter, L. et al

Poster (1999, September)

Detailed reference viewed: 1 (0 ULiège)