scholarly journals Exploring the Antibacterial Activity of Pestalotiopsis spp. under Different Culture Conditions and Their Chemical Diversity Using LC–ESI–Q–TOF–MS

2020 ◽  
Vol 6 (3) ◽  
pp. 140
Author(s):  
Madelaine M. Aguilar-Pérez ◽  
Daniel Torres-Mendoza ◽  
Roger Vásquez ◽  
Nivia Rios ◽  
Luis Cubilla-Rios

As a result of the capability of fungi to respond to culture conditions, we aimed to explore and compare the antibacterial activity and chemical diversity of two endophytic fungi isolated from Hyptis dilatata and cultured under different conditions by the addition of chemical elicitors, changes in the pH, and different incubation temperatures. Seventeen extracts were obtained from both Pestalotiopsis mangiferae (man-1 to man-17) and Pestalotiopsis microspora (mic-1 to mic-17) and were tested against a panel of pathogenic bacteria. Seven extracts from P. mangiferae and four extracts from P. microspora showed antibacterial activity; while some of these extracts displayed a high-level of selectivity and a broad-spectrum of activity, Pseudomonas aeruginosa was the most inhibited microorganism and was selected to determine the minimal inhibitory concentration (MIC). The MIC was determined for extracts man-6 (0.11 μg/mL) and mic-9 (0.56 μg/mL). Three active extracts obtained from P. mangiferae were analyzed by Liquid Chromatography-Electrospray Ionization-Quadrupole-Time of Flight-Mass Spectrometry (LC–ESI–Q–TOF–MS) to explore the chemical diversity and the variations in the composition. This allows us to propose structures for some of the determined molecular formulas, including the previously reported mangiferaelactone (1), an antibacterial compound.

2016 ◽  
Vol 5 (3) ◽  
pp. 27-32 ◽  
Author(s):  
Ahmed I. Khattab ◽  
Eltahir H. Babiker ◽  
Humodi A. Saeed

The objectives of this study were to isolate and identify Streptomyces from soil sediments as well as to optimize cultural growth conditions for maximum antibacterial productivity. A total of fifty soil sediments were collected from Red Sea, Sudan. The soil sediments were pretreated and cultivated on agar medium. Promising Streptomyces spp. were isolated by agar overlay method using indicator organisms. Optimization of chemical and physical culture conditions was carried out. The later was judged by assessment of antibacterial activity. Ethyl acetate was used to extract the secondary metabolite compounds. The separation of the active ingredients was performed using both thin layer chromatography (TLC) and gas chromatography-mass spectrometer (GC-MS). The results revealed nine strains of Streptomyces. Of them two (PS1 and PS28) isolates exhibited high activity against pathogenic bacteria. The optimum growth conditions were pH 7.5, temperature at 30°C, soyabean concentration 2.5 g/l, incubation period in 7 days, MgSO4.7H2O conc. 1g/l and K2HPO4 conc. 2.5g/l. TLC test showed three and two fragments from metabolites of PS1 and PS28 respectively, while the GC-MS analysis revealed eight and eleven compounds with antibacterial activity of PS1 and PS28 respectively. It is concluded that marine is promising source of secondary metabolites.Khattab et al., International Current Pharmaceutical Journal, February 2016, 5(3): 27-32


2014 ◽  
Vol 1 (1) ◽  
pp. 5
Author(s):  
Umasankar Kulandaivelu ◽  
Bhawatha Chawada ◽  
Shireesha Boyapati ◽  
Alavala Rajasekhar Reddy

Arylalkylidene derivatives of aminotriazoles (3a-3j) were synthesized and tested for their antimicrobial and anticancer activity. Four non-pathogenic bacteria [E. coli (NCIM 2068), K. pneumoniae (NCIM 2957), S. aureus (NCIM 2079), B. subtilis (NCIM 2921)] two fungi [C. albicans, A. niger] and two cancer cell lines [HBL-100 and HT-29] were employed in the study. All the compounds were found to have better antibacterial activity against B. subtilis than Ciprofloxacin (standard) and compound 3i was equivalent to Ciprofloxacin in inhibiting S. aureas. Similarly all the compounds inhibited the growth of A. niger better than Fluconazole and compound 3c was equivalent to Fluconazole (standard) in inhibiting C. albicans. In case of anticancer activity none of the molecule exhibited activity better than the standard used (Methotrexate), though they have inhibitory concentration at submicromolar level.


Author(s):  
Na Li ◽  
Jiang-Kun Dai ◽  
Dan Liu ◽  
Jin-Yi Wang ◽  
Jun-Ru Wang

Natural products are an important source of antibacterial agents. Canthin-6-one alkaloids have displayed potential antibacterial activity based on our previous work. In order to improve the activity, twenty-two new 3-N-benzylated 10-methoxy canthin-6-ones were designed and synthesized through quaternization reaction. The in vitro antibacterial activity against three bacteria was evaluated by double dilution method. Four compounds (6f, 6i, 6p and 6t) displayed 2-fold superiority (minimum inhibitory concentration (MIC) = 3.91 µg/mL) against agricultural pathogenic bacteria R. solanacearum and P. syringae than agrochemical propineb. Moreover, the structure–activity relationships (SARs) were also carefully summarized in order to guide the development of antibacterial canthin-6-one agents.


2020 ◽  
Vol 17 (36) ◽  
pp. 18-31
Author(s):  
Ahmad khadem HACHIM ◽  
Rashid Rahim HATEET ◽  
Tawfik Muhammad MUHSIN

The purpose of the present work aimed at exploring the potential biochemical components and biological activities of an organic extract of the white truffle Tirmania nivea collected from the Iraqi desert, then test the organic extract against the Cytotoxicity on Human Larynx carcinoma cells and selected strains of pathogenic bacteria. Fourier transform infrared spectroscopy (FTIR) and gas chromatography-mass spectrometry GC/MSS were used to analyze mycochemical compositions. The antibacterial activity and Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) was investigated using a disk diffusion agar method. The truffle extract's cytotoxicity effect against the larynx cell line (Hep-2) was assessed by the MTT assay (in vitro). FTIR results provided the presence of phenol, carboxylic acid, and alkane's functional group, The GC-MS analysis of T. nivea disclose the existence of nineteen compounds that can contribute to the pharmaceutical properties of the truffle. As for antibacterial activity result, A growth inhibition activity of truffle extract at (18-40 mm inhibition zones) against the tested pathogenic bacterial strains was detected, which minimum inhibitory concentration values ranged from 3.12 to 6.25 mg/mL for Escherichia coli (ATCC 25922) and Staphylococcus aureus (ATCC 25923) Respectively. The results of cytotoxicity shown that the organic truffle extract exhibited a high inhibitory rate (52.685%) against cell line (Hep-2) at a concentration of 1.56 ?g/mL. In this work, the results showed that the organic extracts of T. nivea are very promising as cancer cytotoxicity and antibacterial agent for future medical applications.


Author(s):  
Nilushi Indika Bamunuarachchi ◽  
Fazlurrahman Khan ◽  
Young-Mog Kim

Background: With the growing incidence of microbial pathogenesis, several alternative strategies have been developed. The number of treatments using naturally (e.g., plants, algae, fungi, bacteria, and animals) derived compounds has increased. Importantly, marine-derived products have become a promising and effective approach to combat the antibiotic resistance properties developed by bacterial pathogens. Furthermore, augmenting the sub-inhibitory concentration of the naturally-derived antimicrobial compounds (e.g., hydroxycinnamic acids, terpenes, marine-derived polysaccharides, phenolic compounds) into the naturally derived extracts as a combination therapy to treat the bacterial infection has not been well studied. Objective: The present study was aimed to prepare green algae Ulva lactuca extract and evaluate its antibacterial activity towards Gram-positive and Gram-negative human pathogenic bacteria. Also, revitalize the antibacterial efficiency of the naturally-derived antimicrobial drugs and conventional antibiotics by augmenting their sub-MIC to the U. lactuca extracts. Methods: Extraction was done using a different organic solvent, and its antibacterial activity was tested towards Gram-positive and Gram-negative pathogens. The minimum inhibitory concentration (MIC) of U. lactuca extracts has been determined towards pathogenic bacteria using the micro broth dilution method. The viable cell counting method was used to determine the minimum bactericidal concentration (MBC). The fractional inhibitory concentration (FIC) assay was utilized to examine the combinatorial impact of sub-MIC of two antibacterial drugs using the micro broth dilution method. The chemical components of the extract were analyzed by GC-MS analysis. Results: Among all the extracts, n-hexane extract was found to show effective antibacterial activity towards tested pathogens with the lowest MIC and MBC value. Furthermore, the n-hexane extracts have also been used to enhance the efficacy of the naturally-derived (derived from plants and marine organisms) compounds and conventional antibiotics at their sub-inhibitory concentrations. Most of the tested antibiotics and natural drugs at their sub-MIC were found to exhibit synergistic and additive antibacterial activity towards the tested bacterial pathogens. Conclusions: The augmenting of U. lactuca n-hexane extracts resulted in synergistic and additive bactericidal effects on Gram-positive and Gram-negative human pathogenic bacteria. The present study shows a new alternative strategy to revitalize the antimicrobial activity of naturally derived compounds for treating human bacterial pathogens.


1970 ◽  
Vol 25 (1) ◽  
pp. 82-84 ◽  
Author(s):  
M Shafiqur Rahman ◽  
M Nural Anwar

Longiverbenone is a naturally occurring sesquiterpene isolated from ethanolic extract of Cyperus scariosus rhizome by solvent-solvent portioning and chromatographic technique. The antibacterial activity of longiverbenone was evaluated against eleven potential human pathogenic bacteria using disc diffusion method. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined by broth macrodilution method. Cytotoxic activity (lethal concentration 50%, LC50) of longiverbenone was determined on new borne brine shrimp (Artemia salina). Longiverbenone showed moderate to good antibacterial activity against the test organisms tested herein. It exhibited the lowest MIC (20 μg/ml) and MBC (80 μg/ml) against Vibrio cholerae. The LC50 of the isolated sesquiterpene was found to be 14.38 μg/ml against new borne brine shrimp. Keywords: Antibacterial activity; Cytotoxic activity (LC50); Cyperus scariosu; Longiverbenone; Minimum inhibitory concentration (MIC)DOI: http://dx.doi.org/10.3329/bjm.v25i1.4866 Bangladesh J Microbiol, Volume 25, Number 1, June 2008, pp 82-84


Author(s):  
Navjot Kaur ◽  
Anjana Bhatia ◽  
Sukhjeet Sidhu

The present study was aimed at assessing the antimicrobial potential of various extracts of Euphorbia thymifolia against human pathogenic strains of Salmonella typhimurium and Shigella boydii. The antibacterial activity was determined by agar disc diffusion and broth microdilution techniques. The results showed that the growth of the organisms were inhibited by both acetone and hexane extracts of Euphorbia thymifolia. The acetone extracts showed significantly higher zones of inhibition. The minimum inhibitory concentration of the leaf and stem extracts were 0.078, 0.156, 0.312mg/ml. The phytochemical analysis was carried out for the different parts of the plant. The qualitative analysis showed that alkaloids, phenols and flavonoids were present in both acetone and hexane extracts. The result of the present study indicate that Euphorbia thymifolia has many medicinal values and can be widely studied to extract natural compounds which are beneficial to human beings.


2016 ◽  
Vol 54 (4) ◽  
pp. 1144-1147 ◽  
Author(s):  
Belén Rodríguez-Sánchez ◽  
M. Jesús Ruiz-Serrano ◽  
Adrián Ruiz ◽  
Markus Timke ◽  
Markus Kostrzewa ◽  
...  

Matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) has demonstrated its ability to promptly identify nontuberculous mycobacteria using the Mycobacteria Library v2.0. However, some species are particularly difficult to identify reliably using this database, providing a low log(score). In this study, the identification power of an updated Mycobacteria Library (v3.0) has been evaluated. Overall, 109 NTM isolates were analyzed with both databases. The v3.0 database allowed a high-level confidence in the identification [log(score) value, ≥1.8] of 91.7% of the isolates versus 83.5% with the v2.0 version (P< 0.01).


Author(s):  
S.M.S. Shariar ◽  
M. Jesmin ◽  
M.M. Ali

Three Schiff bases derived from thiosemicarbazide and ketones (Vanillin, Benzophenone and Acetophenone) were used to study their antibacterial activities against some pathogenic bacteria by disc diffusion method. Of these, benzophenone thiosemicarbazone showed significant antibacterial activity as compared with that of Kanamycin. All these three compounds were found to possess cytotoxic effect. Minimum inhibitory concentration of these compounds was also determined.


Author(s):  
Xue Wan ◽  
Shuang Wang ◽  
Min Wang ◽  
Jinhua Liu ◽  
Yu Zhang

Gram-positive anaerobic cocci (GPAC) are a commensal part of human flora but are also opportunistic pathogens. This is possibly the first study to report a case of Peptoniphilus harei bacteremia in an abdominal aortic aneurysm (AAA) patient. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) failed to identify the isolate and molecular analysis confirmed it as P. harei. A comprehensive literature review revealed that P. harei is an emergent pathogen. This study serves as a reminder for practicing clinicians to include anaerobic blood cultures as part of their blood culture procedures; this is particularly important situations with a high level of suspicion of infection factors in some noninfectious diseases, as mentioned in this publication. Clinical microbiologists should be aware that the pathogenic potential of GPAC can be greatly underestimated leading to incorrect diagnosis on using only one method for pathogen identification. Upgradation and correction of the MALDI-TOF MS databases is recommended to provide reliable and rapid identification of GPAC at species level in medical diagnostic microbiology laboratories.


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