0000000000006894
AUTHOR
Alexandre José Macedo
showing 6 related works from this author
Sphingomonas fennica sp. nov. and Sphingomonas haloaromaticamans sp. nov., outliers of the genus Sphingomonas.
2007
Bacterial isolates obtained from polychlorophenol-contaminated sites in Finland (strain K101T) and from a Dutch drinking water well (strain A175T) were characterized taxonomically. 16S rRNA gene sequence analysis, determination of DNA G+C content, physiological characterization, estimation of the ubiquinone and polar lipid patterns and fatty acid content revealed that strains K101T and A175T were similar to Sphingomonas wittichii RW1T but also showed pronounced differences. The DNA G+C contents of the two novel strains were 63.6 and 66.1 mol%, respectively. On the basis of these results, two novel species of the genus Sphingomonas are described, for which the names Sphingomonas haloaromatic…
Inhibition of bacterial virulence factors of foodborne pathogens by paprika (Capsicum annuum L.) extracts
2022
Abstract Capsicum annuum extracts of different polarities were tested for their antimicrobial, antibiofilm, and anti-Quorum sensing (QS) activity against several pathogenic microorganisms and possible toxic effects using an in vivo model (Galleria mellonella L.). Hexane (HE) and Chloroform extract (CE) were the most active in inhibiting biofilm formation of the eight bacteria tested, with inhibition percentages between 22 and 88% for a concentration of 100 μg/mL. These extracts were potent inhibitors of Staphylococcus aureus biofilm, and microscopy analysis confirmed a significant reduction in adhered cells. Moreover, polystyrene surfaces coated with these extracts decreased Staph. aureus a…
Antibiofilm activity of coriander (Coriander sativum L.) grown in Argentina against food contaminants and human pathogenic bacteria
2020
Abstract Bacterial spoilage of food and other infections are a coordinated mechanism controlled by quorum sensing (QS), which regulate the expression of virulence factors, such as biofilm. The antimicrobial, antibiofilm, anti-QS and anti-swarming properties of hexane (HE), chloroform (CE), ethyl acetate (EAE), methanolic (ME) and total methanolic (TME) extracts of coriander grown in Argentina were investigated. In vivo extracts toxicity using Galleria mellonella L. model and chemical composition (GC-MS) were also assessed. The antibiofilm activity of polystyrene surfaces coated with the most active extracts was evaluated. At non-inhibitory growth concentrations, extracts showed a strong ant…
Laurel extracts inhibit quorum sensing, virulence factors and biofilm of foodborne pathogens
2020
Antimicrobial, antibiofilm, anti-Quorum sensing (QS) and virulence factors inhibitory capacity of different polarity Laurus nobilis extracts against several pathogenic microorganisms were studied. Some extracts exhibited antibiotic effect against Staphylococcus aureus multidrug-resistant strains. However, all extracts (100 µg/mL) inhibited to some extent the biofilm of most bacteria tested (until 40% for Gram-negative and 76% for Gram-positive). Hexane (HE) and chloroform extract (CE) were potent inhibitors of S. aureus biofilm and the microscopies further confirmed an important reduction in adherent cells. Polystyrene surfaces coated with these extracts showed a decrease in bacterial adhes…
Sphingobium aromaticiconvertens sp. nov., a xenobiotic-compound-degrading bacterium from polluted river sediment.
2007
A bacterial strain capable of degrading some monochlorinated dibenzofurans, designated RW16T, was isolated from aerobic River Elbe sediments. The strain was characterized based on 16S rRNA gene sequence analysis, DNA G+C content, physiological characteristics, polyamines, ubiquinone and polar lipid pattern and fatty acid composition. This analysis revealed that strain RW16T represents a novel species of the genus Sphingobium. The DNA G+C content of strain RW16T, 60.7 mol%, is the lowest yet reported for the genus. 16S rRNA gene sequence analysis placed strain RW16T as an outlier in the genus Sphingobium. The name Sphingobium aromaticiconvertens sp. nov. is proposed for this dibenzofuran-min…
Trichomonicidal and parasite membrane damaging activity of bidesmosic saponins from Manilkara rufula.
2017
The infection caused by Trichomonas vaginalis is the most common but overlooked non-viral sexually transmitted disease worldwide. Treatment relies on one class of drugs, the 5-nitroimidazoles, but resistance is widespread. New drugs are urgently needed. We reported the effect of crude and purified saponin fractions of Manilkara rufula against Trichomonas vaginalis. The compound responsible for antitrichomonal activity was isolated and identified as an uncommon bidesmosic saponin, Mi-saponin C. This saponin eliminated parasite viability without toxicity against the human vaginal epithelial line (HMVII). In addition, the isolated saponin fraction improved the metronidazole effect against a me…