scholarly journals Antimicrobial assesment of aroylhydrazone derivatives in vitro

2019 ◽  
Vol 69 (2) ◽  
pp. 277-285 ◽  
Author(s):  
Saša Polović ◽  
Vanja Ljoljić Bilić ◽  
Ana Budimir ◽  
Darko Kontrec ◽  
Nives Galić ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Antifungal Activity ◽  
Biofilm Formation ◽  
Good Activity ◽  
E Coli ◽  
Fluconazole Resistant ◽  
Gentamicin Sulphate

Abstract Aroylhydrazones 1–13 were screened for antimicrobial and antibiofilm activities in vitro. N′-(2-hydroxy-phenylmethylidene)-3-pyridinecarbohydrazide (2), N′-(5-chloro-2-hydroxyphenyl-methylidene)-3-pyridinecarbohydrazide (10), N′-(3,5-chloro-2-hydroxyphenylmethylidene)-3-pyridinecarbohydrazide (11), and N′-(2-hydroxy-5-nitrophenylmethylidene)-3-pyridinecarbohydrazide (12) showed antibacterial activity against Escherichia coli, with MIC values (in µmol mL−1) of 0.18–0.23, 0.11–0.20, 0.16–0.17 and 0.35–0.37, resp. Compounds 11 and 12, as well as N′-(2-hydroxy-3-methoxyphenylmethylidene)-3-pyridinecarbohydrazide (6) and N′-(2-hydroxy-5- methoxyphenylmethylidene)-3-pyridinecarbohydrazide (8) showed antibacterial activity against Staphylococcus aureus, with the lowest MIC values of 0.005–0.2, 0.05–0.12, 0.06–0.48 and 0.17–0.99 µmol mL−1. N′-(2-hydroxy-5-methoxyphenylmethylidene)-3-pyridinecarbohydrazide (7) showed antifungal activity against both fluconazole resistant and susceptible C. albicans strains with IC90 range of 0.18–0.1 µmol mL−1. Only compound 11 showed activity against C. albicans ATCC 10231 comparable to the activity of nystatin (the lowest MIC 4.0 ×10−2 vs. 1.7 × 10−2 µmol mL−1). Good activity regarding multi-resistant clinical strains was observed for compound 12 against MRSA strain (MIC 0.02 µmol mL−1) and compounds 2, 6 and 12 against ESBL+ E. coli MFBF 12794, with the lowest MIC for compound 12 (IC50 0.16 µmol mL−1). Anti-biofilm activity was found for compounds 2 (MBFIC 0.015–0.02 µmol mL−1 against MRSA) and 12 (MBFIC 0.013 µmol mL−1 against EBSL+ E. coli). In the case of compound 2 against MRSA biofilm formation, MBFIC values were comparable to those of gentamicin sulphate, whereas in the case of compound 12 and EBSL+ E. coli even more favourable activity compared to gentamicin was observed.

Synthesis of Chalcones and Nucleosides Incorporating [1, 3, 4]Oxadiazolenone Core and Evaluation of their Antifungal and Antibacterial Activities

2020 ◽  
Vol 15 (6) ◽  
pp. 665-679
Author(s):  
Alok K. Srivastava ◽  
Lokesh K. Pandey
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Bacillus Subtilis ◽  
Antifungal Activity ◽  
Aspergillus Niger ◽  
Gram Negative ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
Good Antibacterial Activity

Background: [1, 3, 4]oxadiazolenone core containing chalcones and nucleosides were synthesized by Claisen-Schmidt condensation of a variety of benzaldehyde derivatives, obtained from oxidation of substituted 5-(3/6 substituted-4-Methylphenyl)-1, 3, 4-oxadiazole-2(3H)-one and various substituted acetophenone. The resultant chalcones were coupled with penta-O-acetylglucopyranose followed by deacetylation to get [1, 3, 4] oxadiazolenone core containing chalcones and nucleosides. Various analytical techniques viz IR, NMR, LC-MS and elemental analysis were used to confirm the structure of the synthesised compounds.The compounds were targeted against Bacillus subtilis, Staphylococcus aureus and Escherichia coli for antibacterial activity and Aspergillus flavus, Aspergillus niger and Fusarium oxysporum for antifungal activity. Methods: A mixture of Acid hydrazides (3.0 mmol) and N, Nʹ- carbonyl diimidazole (3.3 mmol) in 15 mL of dioxane was refluxed to afford substituted [1, 3, 4]-oxadiazole-2(3H)-one. The resulted [1, 3, 4]- oxadiazole-2(3H)-one (1.42 mmol) was oxidized with Chromyl chloride (1.5 mL) in 20 mL of carbon tetra chloride and condensed with acetophenones (1.42 mmol) to get chalcones 4. The equimolar ratio of obtained chalcones 4 and β -D-1,2,3,4,6- penta-O-acetylglucopyranose in presence of iodine was refluxed to get nucleosides 5. The [1, 3, 4] oxadiazolenone core containing chalcones 4 and nucleosides 5 were tested to determined minimum inhibitory concentration (MIC) value with the experimental procedure of Benson using disc-diffusion method. All compounds were tested at concentration of 5 mg/mL, 2.5 mg/mL, 1.25 mg/mL, 0.62 mg/mL, 0.31 mg/mL and 0.15 mg/mL for antifungal activity against three strains of pathogenic fungi Aspergillus flavus (A. flavus), Aspergillus niger (A. niger) and Fusarium oxysporum (F. oxysporum) and for antibacterial activity against Gram-negative bacterium: Escherichia coli (E. coli), and two Gram-positive bacteria: Staphylococcus aureus (S. aureus) and Bacillus subtilis(B. subtilis). Result: The chalcones 4 and nucleosides 5 were screened for antibacterial activity against E. coli, S. aureus and B. subtilis whereas antifungal activity against A. flavus, A. niger and F. oxysporum. Compounds 4a-t showed good antibacterial activity whereas compounds 5a-t containing glucose moiety showed better activity against fungi. The glucose moiety of compounds 5 helps to enter into the cell wall of fungi and control the cell growth. Conclusion: Chalcones 4 and nucleosides 5 incorporating [1, 3, 4] oxadiazolenone core were synthesized and characterized by various spectral techniques and elemental analysis. These compounds were evaluated for their antifungal activity against three fungi; viz. A. flavus, A. niger and F. oxysporum. In addition to this, synthesized compounds were evaluated for their antibacterial activity against gram negative bacteria E. Coli and gram positive bacteria S. aureus, B. subtilis. Compounds 4a-t showed good antibacterial activity whereas 5a-t showed better activity against fungi.

Rosemary and Tea Tree Essential Oils Exert Antibiofilm Activities In Vitro against Staphylococcus aureus and Escherichia coli

2020 ◽  
Vol 83 (7) ◽  
pp. 1261-1267
Author(s):  
TING LIU ◽  
JINGFAN WANG ◽  
XIAOMAN GONG ◽  
XIAOXIA WU ◽  
LIU LIU ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Essential Oil ◽  
Biofilm Formation ◽  
Gas Chromatography Mass Spectrometry ◽  
Tea Tree ◽  
E Coli ◽  
Microdilution Method ◽  
Broth Microdilution Method

ABSTRACT The purpose of the present study was to determine the bioactive compounds in rosemary essential oil (REO) and tea tree essential oil (TEO) and to investigate their antibacterial and antibiofilm activities against Staphylococcus aureus and Escherichia coli in vitro. The MIC and MBC assays were performed to assess the antibacterial activity of these two EOs against S. aureus and E. coli with the broth microdilution method. A crystal violet assay was used to ascertain the effects of EOs on the biofilm formation of the test strains, and a tetrazolium bromide (MTT) assay was used to measure the level of inactivation of mature biofilms by EOs. Gas chromatography–mass spectrometry revealed 15 compounds in REO and 27 compounds in TEO, representing 97.78 and 98.13% of the total EO, respectively. Eucalyptol and α-pinene were found in high concentrations in REO, and the two major compounds in TEO were 4-terpineol and terpinolene. The MICs of REO for the two S. aureus and E. coli test strains were both 0.5 mg/mL, and the MICs of TEO for the two strains were both 0.25 mg/mL. Therefore, these EOs can significantly inhibit the formation of biofilms and induced morphological biofilm changes, as verified by scanning electron microscopy. Both EOs had destructive effects on the mature biofilm of the two test strains. TEO was more inhibitory than REO for biofilm formation by the two test strains. HIGHLIGHTS

scholarly journals Synthesis of antibiotic loaded polylactic acid nanoparticles and their antibacterial activity against Escherichia coli O157:H7 and methicillin-resistant Staphylococcus aureus

Biomédica ◽  
2017 ◽  
Vol 37 (1) ◽  
pp. 11 ◽  
Author(s):  
Mónica Tatiana Herrera ◽  
Jhon Jhamilton Artunduaga ◽  
Claudia Cristina Ortiz ◽  
Rodrigo Gonzalo Torres
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Polylactic Acid ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Escherichia Coli O157 ◽  
Methicillin Resistant ◽  
E Coli

Introducción. Las nanopartículas poliméricas constituyen una herramienta nanotecnológica que podría ayudar a combatir los microorganismos patógenos que han desarrollado resistencia a los antibióticos convencionales.Objetivo. Sintetizar nanopartículas de ácido poliláctico cargadas con ofloxacina y vancomicina, y determinar su actividad antibacteriana frente a Escherichia coli O157:H7 y Staphylococcus aureus resistente a la meticilina (SARM).Materiales y métodos. Las nanopartículas de ácido poliláctico cargadas con ofloxacina y vancomicina se sintetizaron utilizando el método de emulsión y evaporación de solvente. Se caracterizaron mediante dispersión de luz en modo dinámico, electroforesis Doppler con láser y microscopía electrónica de barrido (S-TEM). Se evaluó la actividad antibacteriana in vitro de las nanopartículas de ácido poliláctico con ofloxacina contra E. coli O157:H7 y nanopartículas de ácido poliláctico con vancomicina contra SARM, mediante el método de microdilución en caldo.Resultados. Se obtuvieron nanopartículas poliméricas con tamaños inferiores a 379 nm y carga superficial positiva de hasta 21 mV. Las nanopartículas cargadas con ofloxacina presentaron una concentración inhibitoria mínima (CIM50) de 0,001 μg/ml frente a E. coli O157:H7, valor 40 veces menor que la concentración de antibiótico libre necesaria para lograr el mismo efecto (CIM50=0,04 μg/ml). Para SARM, las nanopartículas mejoraron la potencia farmacológica in vitro de la vancomicina alexhibir una MIC50 de 0,005 μg/ml, comparada con la de 0,5 μg/ml del antibiótico libre.Conclusiones. Se mejoró el efecto antibacteriano de la ofloxacina y la vancomicina incorporadas en la matriz polimérica de ácido poliláctico. Las nanopartículas poliméricas constituirían una alternativa para el control de cepas bacterianas de interés en salud pública.

scholarly journals Antibacterial and Antifungal Activity of the Extracts of Different Parts of Avicennia marina (Forssk.) Vierh

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 252
Author(s):  
Mohammad K. Okla ◽  
Abdulrahman A. Alatar ◽  
Saud S. Al-amri ◽  
Walid H. Soufan ◽  
Altaf Ahmad ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Antifungal Activity ◽  
Aspergillus Fumigatus ◽  
Ethanolic Extract ◽  
Avicennia Marina ◽  
E Coli

Increased problems associated with side effects and bacterial resistance of chemical drugs has prompted the research focus on herbal medicines in the past few decades. In the present investigation, the antimicrobial activity of the various parts of Avicennia marina (AM), a mangrove plant, has been evaluated. The plants were collected from the Jazan area of the Kingdom of Saudi Arabia. Primary extracts of roots, stem, leaves, fruits, and seeds were made in ethanol and fractioned in ethanol, ethyl acetate, petroleum ether, chloroform, and water. Minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of the extracts were determined against Bacillussubtilis, Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. It has been observed that the chloroform extract of roots of the AM exhibited inhibitory effects against both S. aureus (MIC = 1.5 ± 0.03 mg/mL) and E. coli (MIC = 1.7 ± 0.01 mg/mL). The ethanolic extract of the AM roots has shown antibacterial activity against Pseudomonas aeruginosa (MIC = 10.8 ± 0.78 mg/mL), Bacillussubtilis (MIC = 6.1 ± 0.27 mg/mL), Staphylococcus aureus (MIC = 2.3 ± 0.08 mg/mL), and Escherichia coli (MIC = 6.3 ± 0.28 mg/mL). The leaf extract of the AM in ethyl acetate showed antibacterial activity against S. aureus and E. coli. Antifungal activity of these extracts was also investigated against Aspergillus fumigatus and Candida albicans. Ethanolic extract of roots and seeds of the AM has shown antifungal activity against Aspergillus fumigatus when applied individually. Ethanolic extract of the AM fruits has shown an inhibitory effect on the growth of Aspergillus fumigatus and Candida albicans. It is suggested that the plant extracts of AM have tremendous antimicrobial activity against a group of microbes, and this effect depends on both the plant part and the solvent used for extraction. Therefore, this plant can be considered to treat various diseases caused by antibiotic-resistant bacteria.

scholarly journals AKTIVITAS ANTIBAKTERI EKSTRAK METANOL BATANG BIDARA LAUT (Strychnos ligustrina) TERHADAP BAKTERI PATOGEN

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Edy Kurniawan ◽  
Dwi Soelistya Dyah Jekti ◽  
Lalu Zulkifli
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Pathogenic Bacteria ◽  
Inhibitory Concentration ◽  
Methanol Extract ◽  
Klebsiella Pneumonia ◽  
E Coli

Abstract : Strychnos ligustrina stem has been empirically used by the people of West Nusa Tenggara and Bali in the treatment of malaria, tooth ache and diarrhea, but there is no scientific data that supports it. This study aims to determine and prove the antibacterial activity of Strychnos ligustrina methanol extract to pathogenic bacteria in vitro and in vivo. This research is an experimental study conducted by measuring the inhibition zone (mm) growth of pathogenic bacteria, determining minimum inhibitory concentration (MIC) and minimum killing concentration (MKC) in vitro, and determining the percentage of antibacterial activity of methanol extract of S. ligustrina stem in vivo. The experiment was conducted using 4 groups of concentrations of S. ligustrina stem methanol extract in an in vitro study of 25, 50, 75, and 100% with ciprofloxacin as a positive control and aquadest as a negative control. In vivo studies experiments were carried out using 6 treatment groups of test animals male mice Balb / c (Mus musculus). The in vitro test results showed that methanol extract of S. ligustrina stems was able to inhibit the growth of pathogenic bacteria with medium categories of clinical isolates of Staphylococcus aureus and categories of weaks to Klebsiella pneumonia and Escherichia coli isolates. The minimum inhibitory concentration (MIC) for S. aureus and K. pneumonia bacteria isolates was at a concentration of 25% while for E. coli isolates at a concentration of 30%. The methanol extract of the S. ligustrina stem has no killing power against the pathogenic bacteria tested. Antibacterial activity in vivo was able to inhibit the growth of S. aureus pathogenic bacteria by 6.60% (at 25% concentration), 8.62% (at 50% concentration), and 17.31% (at 100% concentration), against K. pneumonia was 11.85% (at 25% concentration), 51.21% (at 50% concentration), and 65.92% (at 100% concentration), against E. coliat 19.18% (at concentration 25%), 29.98% (at 50% concentration), and 40.88% (at 100% concentration). Methanol extract of S. ligustrina stem proved to have antibacterial activity in vitro and in vivo. Key words: Srychnos ligustrina, pathogenic bacteria, antibacterial, in vitro, in Vivo. Abstrak : Strychnos ligustrina secara empiris  telah digunakan oleh masyarakat Nusa Tenggara Barat dan Bali dalam pengobatan penyakit malaria, sakit gigi, dan diare, tetapi belum ada data ilmiah yang mendukung. Penelitian ini bertujuan untuk menentukan dan membuktikan aktivitas antibakteri ekstrak metanol batang bidara laut terhadap bakteri patogen secara in vitrodan in vivo. Penelitian ini merupakan penelitian eksperimental yang dilakukan dengan mengukur zona hambat (mm) pertumbuhan bakteri patogen, menentukan konsentrasi hambat minimum (KHM) dan konsentrasi bunuh minimum (KBM) secara in vitro, serta menentukan persentase aktivitas antibakteri ekstrak metanol batang bidara laut secara in vivo. Percobaan dilakukan menggunakan 4 kelompok konsentrasi ekstrak metanol batang bidara laut pada penelitian in vitro yaitu 25, 50, 75, dan 100% dengan ciprofloxacin sebagai kontrol positif serta aquadest sebagai kontrol negatif. Pada penelitian in vivo percobaan dilakukan menggunakan 6 kelompok perlakuan hewan uji mencit jantan galur Balb/c (Mus musculus). Hasil uji in vitro menunjukkan ekstrak metanol batang bidara laut mampu menghambat pertumbuhan bakteri patogen dengan kategori sedang terhadap Staphylococcus aureus isolat klinis dan kategori lemah terhadap Klebsiella pneumonia dan Escherichia coli isolat klinis. Nilai konsentrasi hambat minimum (KHM) untuk isolat bakteri S. aureus dan K. pneumoniae adalah pada konsentrasi 25% sedangkan untuk isolat E. coli pada konsentrasi 30%. Ekstrak metanol batang bidara laut tidak memiliki daya bunuh terhadap bakteri patogen yang diuji. Aktivitas antibakteri secara in vivo mampu menghambat pertumbuhan bakteri patogen S. aureus sebesar 6,60% (pada konsentrasi 25%), 8,62% (pada konsentrasi 50%), dan 17,31% (pada konsentrasi 100%), terhadap K. pneumonia sebesar 11,85% (pada konsentrasi 25%), 51,21% (pada konsentrasi 50%), dan 65,92% (pada konsentrasi 100%),   terhadap E. coli sebesar 19,18% (pada konsentrasi 25%), 29,98% (pada konsentrasi 50%), dan 40,88% (pada konsentrasi 100%). Ekstrak metanol batang bidara laut terbukti memiliki aktivitas antibakteri secara in vitro dan in vivo. Kata kunci: Srychnos ligustrina, bakteri patogen, antibakteri, in vitro, in vivo

Substituted 4-Formyl-2H-chromen-2-ones: Their Reaction with N-(2,3,4,6-Tetra-Oacetyl- β-D-galactopyranosyl)thiosemicarbazide, Antibacterial and Antifungal Activity of Their Thiosemicarbazone Products

2020 ◽  
Vol 24 (19) ◽  
pp. 2272-2282
Author(s):  
Vu Ngoc Toan ◽  
Nguyen Minh Tri ◽  
Nguyen Dinh Thanh
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Candida Albicans ◽  
Selenium Dioxide ◽  
Antibacterial And Antifungal Activity ◽  
E Coli ◽  
Antibacterial And Antifungal Activities ◽  
Alkyl Ethers ◽  
Antibacterial And Antifungal

Several 6- and 7-alkoxy-2-oxo-2H-chromene-4-carbaldehydes were prepared from corresponding alkyl ethers of 6- and 7-hydroxy-4-methyl-2-oxo-2H-chromen-2-ones by oxidation using selenium dioxide. 6- and 7-Alkoxy-4-methyl-2H-chromenes were obtained with yields of 57-85%. Corresponding 4-carbaldehyde derivatives were prepared with yields of 41-67%. Thiosemicarbazones of these aldehydes with D-galactose moiety were synthesized by reaction of these aldehydes with N-(2,3,4,6-tetra-O-acetyl-β-Dgalactopyranosyl) thiosemicarbazide with yields of 62-74%. These thiosemicarbazones were screened for their antibacterial and antifungal activities in vitro against bacteria, such as Staphylococcus aureus, Escherichia coli, and fungi, such as Aspergillus niger, Candida albicans. Several compounds exhibited strong inhibitory activity with MIC values of 0.78- 1.56 μM, including 8a (against S. aureus, E. coli, and C. albicans), 8d (against E. coli and A. niger), 9a (against S. aureus), and 9c (against S. aureus and C. albicans).

scholarly journals Differential behaviors of Staphylococcus aureus and Escherichia coli type II DNA topoisomerases.

1996 ◽  
Vol 40 (12) ◽  
pp. 2714-2720 ◽  
Author(s):  
F Blanche ◽  
B Cameron ◽  
F X Bernard ◽  
L Maton ◽  
B Manse ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Strong Support ◽  
Dna Gyrase ◽  
Dna Supercoiling ◽  
Type Ii ◽  
Topoisomerase Iv ◽  
E Coli ◽  
Dna Relaxation

Staphylococcus aureus gyrA and gyrB genes encoding DNA gyrase subunits were cloned and coexpressed in Escherichia coli under the control of the T7 promoter-T7 RNA polymerase system, leading to soluble gyrase which was purified to homogeneity. Purified gyrase was catalytically indistinguishable from the gyrase purified from S. aureus and did not contain detectable amounts of topoisomerases from the E. coli host. Topoisomerase IV subunits GrlA and GrlB from S. aureus were also expressed in E. coli and were separately purified to apparent homogeneity. Topoisomerase IV, which was reconstituted by mixing equimolar amounts of GrlA and GrlB, had both ATP-dependent decatenation and DNA relaxation activities in vitro. This enzyme was more sensitive than gyrase to inhibition by typical fluoroquinolone antimicrobial agents such as ciprofloxacin or sparfloxacin, adding strong support to genetic studies which indicate that topoisomerase IV is the primary target of fluoroquinolones in S. aureus. The results obtained with ofloxacin suggest that this fluoroquinolone could also primarily target gyrase. No cleavable complex could be detected with S. aureus gyrase upon incubation with ciprofloxacin or sparfloxacin at concentrations which fully inhibit DNA supercoiling. This suggests that these drugs do not stabilize the open DNA-gyrase complex, at least under standard in vitro incubation conditions, but are more likely to interfere primarily with the DNA breakage step, contrary to what has been reported with E. coli gyrase. Both S. aureus gyrase-catalyzed DNA supercoiling and S. aureus topoisomerase IV-catalyzed decatenation were dramatically stimulated by potassium glutamate or aspartate (500- and 50-fold by 700 and 350 mM glutamate, respectively), whereas topoisomerase IV-dependent DNA relaxation was inhibited 3-fold by 350 mM glutamate. The relevance of the effect of dicarboxylic amino acids on the activities of type II topoisomerases is discussed with regard to the intracellular osmolite composition of S. aureus.

scholarly journals In vitro and in vivo evaluation of antibacterial activity of Bridelia ferruginea extracts on some clinical isolates

2018 ◽  
Vol 7 (4) ◽  
pp. 392-398
Author(s):  
B.T Yunana ◽  
◽  
B. B Bukar ◽  
J. C Aguiyi ◽  
◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Bark Extract ◽  
Root Extract ◽  
Root Bark ◽  
Zone Of Inhibition ◽  
Bridelia Ferruginea

The ethanol extracts of root, bark and leaf of Bridelia ferruginea was investigated for antibacterial activity against clinical isolate of Staphylococcus aureus and Escherichia coli. The extracts had significant antibacterial activity in vitro at concentration of 25 mg/ml, 50 mg/ml, 100 mg/ml and 200 mg/ml and in vivo at dose of 50 mg/kg and 100 mg/kg. The root extract in vitro had the highest zone of inhibition, followed by the bark extract for both Staphylococcus aureus and Escherichia coli. The concentration of 200 mg/ml had the highest zone of inhibition in vitro. The minimum inhibitory concentration (MIC) showed a decreasing inhibitory effect of the plant extracts for both Staphylococcus aureus and Escherichia coli as the concentration decreases with root having 3.125 mg/ml, bark having 6.25 mg/ml and leaf having 25 mg/ml for Staphylococcus aureus and Escherichia coli. Likewise, the minimum bactericidal concentration (MBC) showed decreasing bactericide effects with decrease concentration with root having 12.5 mg/ml, bark having 12.5 mg/ml and leaf having 25 mg/ml for Escherichia coli while root had 6.25mg/ml, bark had 12.5mg/ml and leaf had 25mg/ml for Staphylococcus aureus. The in vivo investigation showed that the root and bark extract exhibited antibacterial activity on both Staphylococcus aureus and Escherichia coli at doses of 100mg/kg and 50mg/kg; the root extract had higher activity than the bark and root/bark combined. The dose of 100 mg/kg had the highest colonies reduction for Staphylococcus aureus and Escherichia coli in vivo. Preliminary phytochemical screening of root, bark and leaves of Bridelia ferruginea revealed the presence of tannins, flavonoids, carbohydrates, cardiac glycoside (root, bark and leaves), saponins (root and bark). The presence of tannins, saponins, flavonoid, cardiac glycoside and carbohydrate in the bark and root extracts of the plant indicates that the bark and root extracts were pharmacological importance

scholarly journals Evaluation du potentiel antimicrobien et de la toxicité des extraits de Jatropha multifida Linn, (Euphorbiaceae)

2020 ◽  
Vol 151 ◽  
pp. 15550-15558
Author(s):  
Amégninou Agban ◽  
Yao Hoekou ◽  
Passimna Pissang ◽  
Tchadjobo Tchacondo ◽  
Komlan Batawila
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Candida Albicans ◽  
Aqueous Extract ◽  
E Coli ◽  
Toxicological Studies ◽  
Jatropha Multifida

Objectif : L’objectif de ce travail était d’évaluer in vitro l’activité antimicrobienne des extraits de feuilles et tige de Jatropha multifida sur la croissance de Candida albicans, Escherichia coli et Staphylococcus aureus, puis d’évaluer in vivo la toxicité de cette plante. Méthodologie et résultats : Les méthodes de diffusion en milieu gélosé et de microdilution en milieu liquide ont été utilisées pour évaluer l’effet antimicrobien. Une étude en subaigüe était réalisée afin d’explorer les effets toxiques de l’extrait aqueux des feuilles. Les résultats des tests antimicrobiens montrent une activité des extraits de feuilles et tige de J. multifida sur la croissance des souches utilisées avec des diamètres de zones d’inhibition allant de 8 à 25 mm et des concentrations minimales inhibitrices (CMI) variant de 0,039 mg/mL à 1,25 mg/mL à l’exception des souches de E. coli qui sont résistantes aux extraits de la tige. L’administration en subaigüe de l’extrait aqueux des feuilles de J. multifida à la dose de 600 mg/kg entraîne une perte significative de poids chez les souris. Conclusion et applications des résultats : Les extraits aqueux, éthanolique et hydroéthanolique des feuilles et tige de J. multifida possèdent d’activité antimicrobienne et pourraient être utilisés dans le traitement des Candidoses à C. albicans et des infections à S. aureus. Mais l’essai de toxicité subaigüe montre que l’extrait aqueux de la plante serait toxique. Des études toxicologiques approfondies restent donc nécessaires sur ces extraits afin de mieux élucider leur inocuité. Mots-clés : Jatropha multifida, extraits de feuilles et de tige, activités antifongique et antibactérienne, toxicité. Agban et al., J. Appl. Biosci. 2020 Evaluation du potentiel antimicrobien et de la toxicité des extraits de Jatropha multifida Linn, (Euphorbiaceae) 15551 Evaluation of antimicrobial potential and toxicity of Jatropha multifida Linn, (Euphorbiaceae) extracts ABSTRACT Objective: The objective of this study was to evaluate in vitro the antimicrobial activity of leaves and stem of Jatropha multifida extracts against Candida albicans, Escherichia coli and Staphylococcus aureus, and then to evaluate in vivo the toxicity of this plant. Methodology and Results: The agar well-diffusion and the NCCLS broth microdilution methods were used to assess the antimicrobial effect. A subacute study was carried out to explore the toxic effects of the aqueous extract of the leaves. The results of the antimicrobial tests show an activity of the extracts of leaves and stems of J. multifida on the growth of the strains used with diameters of inhibitory zones ranging from 8 to 25 mm and minimum inhibitory concentrations (MIC) varying from 0.039 mg/mL to 1.25 mg/mL exception E. coli strains which are resistant to extracts from the stem. Subacute administration of the aqueous extract of the leaves of J. multifida at a dose of 600 mg/kg leads to a significant loss of weight in the mice. Conclusion and application of findings : The aqueous, ethanolic and hydroethanolic extracts of the leaves and stem of J. multifida have antimicrobial activity and could be used in the treatment of Candidiasis and bacterial infections due respectively to C. albicans and S. aureus. But the subacute toxicity test shows that the aqueous extract of the plant would be toxic. Extensive toxicological studies therefore remain necessary on these extracts in order to better elucidate their safety. Keywords: Jatropha multifida extracts of leaves and stem, antifungal and antibacterial activities, toxicity

scholarly journals Screening of Escherichia coli Species Biodiversity Reveals New Biofilm-Associated Antiadhesion Polysaccharides

mBio ◽  
2011 ◽  
Vol 2 (3) ◽  
Author(s):  
Olaya Rendueles ◽  
Laetitia Travier ◽  
Patricia Latour-Lambert ◽  
Thierry Fontaine ◽  
Julie Magnus ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Bacterial Adhesion ◽  
Bioactive Molecules ◽  
Bacterial Biofilms ◽  
Gram Positive ◽  
Content Type ◽  
E Coli ◽  
Species Biodiversity

ABSTRACTBacterial biofilms often form multispecies communities in which complex but ill-understood competition and cooperation interactions occur. In light of the profound physiological modifications associated with this lifestyle, we hypothesized that the biofilm environment might represent an untapped source of natural bioactive molecules interfering with bacterial adhesion or biofilm formation. We produced cell-free solutions extracted fromin vitromature biofilms formed by 122 naturalEscherichia coliisolates, and we screened these biofilm extracts for antiadhesion molecules active on a panel of Gram-positive and Gram-negative bacteria. Using this approach, we showed that 20% of the tested biofilm extracts contained molecules that antagonize bacterial growth or adhesion. We characterized a compound, produced by a commensal animalE. colistrain, for which activity is detected only in biofilm extract. Biochemical and genetic analyses showed that this compound corresponds to a new type of released high-molecular-weight polysaccharide whose biofilm-associated production is regulated by the RfaH protein. We demonstrated that the antiadhesion activity of this polysaccharide was restricted to Gram-positive bacteria and that its production reduced susceptibility to invasion and provided rapid exclusion ofStaphylococcus aureusfrom mixedE. coliandS. aureusbiofilms. Our results therefore demonstrate that biofilms contain molecules that contribute to the dynamics of mixed bacterial communities and that are not or only poorly detected in unconcentrated planktonic supernatants. Systematic identification of these compounds could lead to strategies that limit pathogen surface colonization and reduce the burden associated with the development of bacterial biofilms on medical devices.IMPORTANCEWe sought to demonstrate that bacterial biofilms are reservoirs for unknown molecules that antagonize bacterial adhesion. The use of natural strains representative ofEscherichia colispecies biodiversity showed that nonbiocidal antiadhesion polysaccharides are frequently found in mature biofilm extracts (bacterium-free suspensions which contain soluble molecules produced within the biofilm). Release of an antiadhesion polysaccharide confers a competitive advantage upon the producing strain against clinically relevant pathogens such asStaphylococcus aureus. Hence, exploring the biofilm environment provides a better understanding of bacterial interactions within complex communities and could lead to improved control of pathogen colonization.

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