scholarly journals Antimicrobial Fatty Acids from Green AlgaUlva rigida(Chlorophyta)

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Amel Ismail ◽  
Leila Ktari ◽  
Yosr Ben Redjem Romdhane ◽  
Brahim Aoun ◽  
Saloua Sadok ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Sampling Site ◽  
Diffusion Method ◽  
Ulva Rigida ◽  
Disk Diffusion Method ◽  
Indicator Microorganisms ◽  
Organic Extracts ◽  
Collection Period ◽  
Layer Chromatography ◽  
Ghar El Melh Lagoon

This study deals with the antimicrobial potential assessment ofUlva rigida,in regard to collection period and sampling site. Besides, we assess the chemical composition of bioactive compounds. For this purpose,Ulva rigidawas seasonally collected from two northern sites in Tunisia, Cap Zebib rocky shore (CZ) and Ghar El Melh lagoon (GEM). Crude organic extracts were prepared using dichloromethane and dichloromethane/methanol and tested against 19 indicator microorganisms using the disk diffusion method and microdilution technique to determine the minimum inhibitory concentration (MIC). Silica gel column and thin layer chromatography were used for purification of active compounds. Nuclear magnetic resonance (NMR) and gas chromatography were used for compounds identification. Samples ofUlva rigidacollected from the two sites have uniform antimicrobial activity throughout the year. Algae collected from the lagoon showed the largest spectrum of activity and were used for subsequent analysis. Bioguided purification of extracts fromUlva rigida,collected at GEM, leads to 16 active fractions with antibacterial effect mainly againstStaphylococcus aureusATCC 25923 andEnterococcus faecalisATCC 29212. These fractions were identified as fatty acids, mainly oleic (C18: 1 w9), linoleic (C18: 2 w6), palmitic (C16: 0), and stearic (C14: 0). MICs values ranged from 10 to 250μg/ml.

Antifungal and Antibacterial Activities of Pentanema divaricatum and Its Active Constituent

2008 ◽  
Vol 63 (9-10) ◽  
pp. 649-652 ◽  
Author(s):  
Nastaran Momen-Roknabadi ◽  
Ahamd R. Gohari ◽  
Hamid R. Monsef-Esfehani ◽  
Farideh Attar ◽  
Reza Hajiaghaee ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Aspergillus Niger ◽  
Preparative Thin Layer Chromatography ◽  
Antibacterial Activities ◽  
Diffusion Method ◽  
Active Constituent ◽  
Disk Diffusion Method ◽  
Bioassay Guided Fractionation ◽  
Layer Chromatography ◽  
And Staphylococcus Aureus

The antimicrobial activity of ethanol and chloroform extracts of Pentanema divaricatum Cass. was studied using the conventional disk diffusion method. The extracts’ highest antimicrobial activity was observed against Aspergillus niger. Bioassay-guided fractionation of the crude extract by preparative thin layer chromatography (PTLC) showed one antimicrobial fraction which was especially effective against Aspergillus niger. By conventional spectroscopy the active fraction was identified as 4α,5α-epoxy-10α,14H-1-epi-inuviscolide. This compound represented the most potent antimicrobial candidate, with MIC values of < 25 μg/disk against A. niger strains and 200 μg/disk against Bacillus cereus and Staphylococcus aureus.

Synthesis of some 1H-1,5-benzodiazepine Series Containing Chromene Ring from α,β-Unsaturated Ketones of 6-Acetyl-5-Hydroxy-4-Methylcoumarin

2020 ◽  
Vol 17 (5) ◽  
pp. 404-410 ◽  
Author(s):  
Duong Ngoc Toan ◽  
Nguyen Dinh Thanh ◽  
Mai Xuan Truong ◽  
Nguyen Minh Thao
Keyword(s):  
Biological Activities ◽  
Absolute Ethanol ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
Unsaturated Ketones ◽  
Molar Ratios ◽  
Antibacterial And Antifungal Activities ◽  
Substituted Benzaldehydes ◽  
Antibacterial And Antifungal ◽  
Layer Chromatography

Background: Reaction of α,β-unsaturated ketones with o-phenylenediamine afforded corresponding 2,3-dihydro-1H-1,5-benzodiazepines. Objective: α,β-Unsaturated ketones of 6-acetyl-5-hydroxy-4-methylcoumarin are precursors for synthesis of 2,3-dihydro-1H-1,5-benzodiazepines by a reaction with o-phenylenediamine. Methods: Enones of 6-acetyl-5-hydroxy-4-methylcoumarin were prepared from this ketone and (un)substituted benzaldehydes in the presence of piperidine, triethylamine, or pyridine as a catalyst in absolute ethanol with 1:1 molar ratios, respectively. 2',3'-Dihydro-1H-1',5'-benzodiazepines were synthesized by using the reaction of these enones with o-phenylenediamine in absolute ethanol in the presence of glacial acetic acid as a catalyst. Their biological activities were evaluated using the disk diffusion method. Results: Seven new 2',3'-dihydro-1H-1',5'-benzodiazepines were obtained and their structures were confirmed by thin-layer chromatography, IR, NMR and MS spectra. Some synthesized benzodiazepines showed antibacterial and antifungal activities against Escherichia coli (Gram-(−) bacterium), Staphylococus epidermidis (Gram-(+) bacterium). Candida albicans (fungus). Conclusion: The formation of enones from 6-acetyl-5-hydroxy-4-methylcoumarin and (un)substituted benzaldehydes could be catalyzed by piperidine, triethylamine, pyridine to afford similar yields. 2',3'-dihydro-1H- 1',5'-benzodiazepines have been synthesized from the aforementioned enones and o-phenylenediamine.

scholarly journals Screening of Bioactive Metabolites Actinomycetes to Evaluate Potential Sources of Sustainable Marine Natural Products

2021 ◽  
Vol 940 (1) ◽  
pp. 012090
Author(s):  
T G P Utami ◽  
A Setiawan ◽  
N L G R Juliasih
Keyword(s):  
Biofilm Formation ◽  
Pathogenic Bacteria ◽  
Methanol Extract ◽  
Bioactive Metabolites ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
Antibiotic Susceptibility Test ◽  
Organic Extracts ◽  
Antibiofilm Agents

Abstract This study aimed to screen the activity of methanol extract of sponge-derived actinomycetes as an anti-biofilm and antibacterial agent to Staphylococcus aureus. Nine actinomycetes isolates were selected from the UPT LTSIT deposit. S. aureus was obtained from the skin of patients at Abdul Moeloek General Hospital. An antibiotic susceptibility test was performed by the disk diffusion method. Biofilm formation of S. aureus was tested using the crystal violet method. The viability of pathogenic bacteria was measured using the indicator resazurin. The results of the biofilm formation test in vitro revealed that the organic extracts 33A1T2, 33A2T3, 21A1T11, and 38A1T12 inhibited bacterial growth at 0.5 mg/mL. Meanwhile, 50A2T9, 21A1T11, and 38A1T12 significantly inhibited the formation of staphylococcal biofilm on polystyrene at a concentration of 0.25 mg/mL. This information is very important as a basis for further understanding of the mechanism of action of antibiofilm agents.

scholarly journals Influence of Environmental and Anthropogenic Factors on Microbial Ecology and Sanitary Threat in the Final Stretch of the Brda River

Water ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 922 ◽  
Author(s):  
Łukasz Kubera ◽  
Marta Małecka-Adamowicz ◽  
Emilia Jankowiak ◽  
Ewa Dembowska ◽  
Piotr Perliński ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Urban Areas ◽  
Sampling Site ◽  
Environmental Parameters ◽  
Diffusion Method ◽  
Anthropogenic Factors ◽  
Bacterial Cells ◽  
Disk Diffusion Method ◽  
Spatio Temporal ◽  
The Impact

Ecology of aquatic microorganisms depends on a number of environmental parameters. The additional influence of anthropogenic factors is connected with sanitary risk, particularly in urban areas. The study was aimed at assessing the impact of physicochemical and biological parameters on the abundance and activity of bacterioplankton under different spatio-temporal conditions in the urbanized section of the Brda River. The evaluation of sanitary pollution of water was accompanied by the assessment of antibiotic resistance of isolated faecal strains determined using the disk diffusion method. The results indicate that the location of sampling sites significantly affected by the distribution of faecal Escherichia coli and enterococci in the studied part of the river. On the other hand, there were no significant seasonal changes in respiratory activity or abundance of planktonic bacteria. In addition, the abundance of bacterioplankton was not correlated with all measured physico-chemical parameters, though it was correlated with the organic carbon oxidation rate. Depending on the sampling site, bacterial cells with damaged membranes constituted between 8% and 20% of the population. Antibiograms showed the absence of multi-drug resistant strains. Enterococci exhibited the highest resistance to imipenem (45%), while Escherichia coli, to cefoxitin (31%).

scholarly journals The potency of Sansevieria trifasciata and S. cylindrica leaves extracts as an antibacterial against Pseudomonas aeruginosa

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Whika Dewatisari ◽  
Laurentius Hartanto Nugroho ◽  
Endah Retnaningrum ◽  
Yekti Asih Purwestri
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibacterial Activity ◽  
Bioactive Compounds ◽  
Ethanolic Extract ◽  
Inhibition Zone ◽  
Diffusion Method ◽  
Phytochemical Analysis ◽  
Disk Diffusion Method ◽  
Vacuum Liquid Chromatography ◽  
Layer Chromatography

Abstract. Nugroho LH, Dewatisari WF, Retnaningrum E, Purwestri YA. 2021. The potency of Sansevieria trifasciata and S. cylindrica leaves extracts as an antibacterial against Pseudomonas aeruginosa. Biodiversitas 22: 408-415. Sansevieria trifasciata and Sansevieria cylindrica are the major herbs in Indonesia, which contain several bioactive compounds as potential sources of antibacterial agents. This study aims to evaluate the antibacterial activity of S. trifasciata and S. cylindrica leaves extract and fraction against Pseudomonas aeruginosa and to identify its bioactive compounds. Crude ethanolic extract of S. trifasciata and S. cylindrica leaves were tested for their antimicrobial activity by disk diffusion method against P. aeruginosa. S. trifasciata showed strong antibacterial activity with an inhibition zone of 18.3 mm compared to S. cylindrica. Different concentrations of extract i.e. 4 mg/mL, 8 mg/mL, 16 mg/mL, 32 mg/mL, 64 mg/mL, 128 mg/mL and 256 mg/mL were tested for their minimum inhibitory concentrations (MIC). The MIC results showed that the S. trifasciata extract was able to inhibit bacterial growth at a concentration of 32 mg/mL. Results of vacuum liquid chromatography (VLC) and thin-layer chromatography (TLC) revealed that only fraction 3 showed the highest antibacterial activity at 16 mg/mL. In TLC bioautography analysis, fraction 3 showed a clear zone at Rf 0.93. The phytochemical analysis showed that terpenoid, phenolic, triterpenoid, and flavonoid compounds were found in S. trifasciata extract that were associated with antibacterial activity.

scholarly journals Phytochemical Screening and Bioactivity Determination of Ethyl Acetate and Methanolic Extracts of Leaf and Bark of the Plant Nyctanthes arbortristis L.

2020 ◽  
pp. 145-151
Keyword(s):  
Ethyl Acetate ◽  
Extraction Procedure ◽  
Radical Scavenging ◽  
Antioxidant Property ◽  
Diffusion Method ◽  
Bark Extract ◽  
Phytochemical Screening ◽  
Disk Diffusion Method ◽  
Methanolic Extracts ◽  
Layer Chromatography

The present study targeted to evaluate the phytoconstituents of Nyctanthes arbortristis Linn., and its biological activity. By solvent extraction procedure, a total of four extracts were designated from the leaf and bark of the plant using two solvents (leaf extract in ethyl acetate and methanol: NALE & NALM; bark extract in ethyl acetate and methanol: NABE & NABM). Phytochemical screening was conducted by qualitative analysis and thin-layer chromatography. Parallelly, antioxidant property (by DPPH free radical scavenging method) and antimicrobial activity (by disk diffusion method) were also investigated to determine bioactivity. The presence of alkaloids and glycosides was detected by qualitative phytochemical assay of the extracts. Furthermore, TLC successfully observed the versatility of the compound's presence, such as phenolic compounds, different alkaloids, and glycosides. In DPPH assay, methanolic extracts are highly capable of scavenging the radicals than the ethyl acetate extracts. Surprisingly, IC50 for NABM (1.69 µg/ml) is less than ascorbic acid (3.58µg/ml), which is an exploration of the excellent antioxidant potential of the plant. But any extracts showed no positive result in the antimicrobial test against gram-positive or gram-negative bacteria, even against yeast.

Prevalence of SHV-extended spectrum β-lactamase producing carbapenem –resistantKlebsiellapneumoniae among patients with lower respiratory tractinfections in Babylon Province-Iraq.

2018 ◽  
Vol 9 (SPL1) ◽  
Author(s):  
Fatima Moeen Abbas
Keyword(s):  
Resistance Rate ◽  
Combination Method ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
Carbapenem Resistant ◽  
Extended Spectrum ◽  
Pcr Method ◽  
Polymerase Chain ◽  
Tract Infections ◽  
Positive Results

This study was carried out to screen the prevalence of Klebsiella pneumoniae isolated from patients with lower respiratory tract infections in Babylon province.From December,2015 to the end of March,2016,a total of 100 sputum samples were collected from patients visited or hospitalized Merjan Teaching Hospital and Al- Hashimya General Hospital. Fifteenth (65%) isolates were identified as Klebsiellapneumoniae. All bacterial isolates were evaluated for extended spectrum β-lactamase (ESBL) production phenotypically using disk combination method. Eleven (73.3%) isolates were detected as ESBL-producers. Kirby-Bauer disk diffusion method was employed to determine resistance profile of ESBLs-positive isolates. Higher rates of resistance were observed for ampicillin and piperacillin antibiotics with (81.8%) and (72.7%) resistance rate, respectively, while the lowest rate was noticed for imipenem antibiotic (14.28%). Carbapenem-resistant isolates were investigated for blaSHV gene by Polymerase Chain Reaction (PCR) method, 2 (100%) isolates gave positive results.

Antibiotic Susceptibility Evaluation of Bacterial Agents Causing Infection in Children with Acute Tonsillopharyngitis

2020 ◽  
Vol 20 ◽  
Author(s):  
Hamidreza Sherkatolabbasieh ◽  
Majid Firouzi ◽  
Shiva Shafizadeh ◽  
Iman Amiri
Keyword(s):  
Sore Throat ◽  
Predictive Value ◽  
Positive Culture ◽  
Clinical Score ◽  
Streptococcal Pharyngitis ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
Cross Sectional ◽  
Clinical Sensitivity ◽  
Group A

Background: The aim of this study is to evaluate the prevalence of group A beta-hemolytic pharyngitis by assessing the outcome of the culture and the resistance and sensitivity of group A beta hemolytic streptococcus to antibiotics. Methods: This cross-sectional study was conducted on 170 patients, aged 3-15 years, referred to the clinic with complaints of sore throat. Patients’ history was collected and physical examination was performed and were score based on clinical findings. Patients with other underlying pathologies and those taking antibiotics prior to the study were excluded from our study. Antimicrobial susceptibility test was performed by disk diffusion method against cephalexin, cefazolin, erythromycin and amoxicillin. Results: A total of 170 patients were reported with sore throat. Patients with positive culture results were 60% male and 40% female. Amoxicillin resistance was the greatest (5%) in the culture. All isolated bacteria were sensitive to amoxicillin, cephalexin, cefazolin and erythromycin. Patients with McIssac score ≥ 6 showed clinical sensitivity 75% specificity 61% negative predictive value 94.8% and positive predictive value 20.3% for Group A beta-hemolytic streptococcal pharyngitis. Conclusion: The results showed the higher the clinical score, the greater the chance of positive throat culture.

scholarly journals Predominance of PVL-negative community-associated methicillin-resistant Staphylococcus aureus sequence type 8 in newly diagnosed HIV-infected adults, Tanzania

2021 ◽  
Author(s):  
Joel Manyahi ◽  
Sabrina J. Moyo ◽  
Said Aboud ◽  
Nina Langeland ◽  
Bjørn Blomberg
Keyword(s):  
Staphylococcus Aureus ◽  
Hiv Infection ◽  
Diffusion Method ◽  
Molecular Characteristics ◽  
People Living With Hiv ◽  
Newly Diagnosed ◽  
Beta Lactam ◽  
Disk Diffusion Method ◽  
Methicillin Resistant ◽  
Inducible Clindamycin Resistance

AbstractDifficult-to-treat infections caused by methicillin-resistant Staphylococcus aureus (MRSA) are of concern in people living with HIV infection as they are more vulnerable to infection. We aimed to identify molecular characteristics of MRSA colonizing newly diagnosed HIV-infected adults in Tanzania. Individuals newly diagnosed with HIV infection were recruited in Dar es Salaam, Tanzania, from April 2017 to May 2018, as part of the randomized clinical trial CoTrimResist (ClinicalTrials.gov identifier: NCT03087890). Nasal/nasopharyngeal isolates of Staphylococcus aureus were susceptibility tested by disk diffusion method, and cefoxitin-resistant isolates were characterized by short-reads whole genome sequencing. Four percent (22/537) of patients carried MRSA in the nose/nasopharynx. MRSA isolates were frequently resistant towards gentamicin (95%), ciprofloxacin (91%), and erythromycin (82%) but less often towards trimethoprim-sulfamethoxazole (9%). Seventy-three percent had inducible clindamycin resistance. Erythromycin-resistant isolates harbored ermC (15/18) and LmrS (3/18) resistance genes. Ciprofloxacin resistance was mediated by mutations of the quinolone resistance-determining region (QRDR) sequence in the gyrA (S84L) and parC (S80Y) genes. All isolates belonged to the CC8 and ST8-SCCmecIV MRSA clone. Ninety-five percent of the MRSA isolates were spa-type t1476, and one exhibited spa-type t064. All isolates were negative for Panton-Valentine leucocidin (PVL) and arginine catabolic mobile element (ACME) type 1. All ST8-SCCmecIV-spa-t1476 MRSA clones from Tanzania were unrelated to the globally successful USA300 clone. Carriage of ST8 MRSA (non-USA300) was common among newly diagnosed HIV-infected adults in Tanzania. Frequent co-resistance to non-beta lactam antibiotics limits therapeutic options when infection occurs.

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