Antimicrobial and cytotoxic activity of Macrophomina phaseolina isolated from gummosis infected citrus reticulata

Author(s):  
Rubal C Das ◽  
Rajib Banik ◽  
Robiul Hasan Bhuiyan ◽  
Md Golam Kabir

Macrophomina phaseolina is one of the pathogenic organisms of gummosis disease of orange tree (Citrus reticulata). The pathogen was identified from the observation of their colony size, shape, colour, mycelium, conidiophore, conidia, hyaline, spore, and appressoria in the PDA culture. The crude chloroform extracts from the organism showed antibacterial activity against a number of Gram positive and Gram-negative bacteria. The crude chloroform extract also showed promising antifungal activity against three species of the genus Aspergillus. The minimum inhibitory concentration (MIC) of the crude chloroform extract from M. phaseolina against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Shigella sonnie were 128 ?gm, 256 ?gm, 128 ?gm and 64 ?gm/ml respectively. The LD50 (lethal dose) values of the cytotoxicity assay over brine shrimp of the crude chloroform extract from M. phaseolina was found to be 51.79 ?gm/ml. DOI: http://dx.doi.org/10.3329/cujbs.v5i1.13378 The Chittagong Univ. J. B. Sci.,Vol. 5(1 &2):125-133, 2010

Author(s):  
Firza Shafique ◽  
Uzma Naureen ◽  
Annam Zikrea ◽  
Qurban Ali ◽  
Rumana Sadiq ◽  
...  

The development of antibiotic resistant bacteria causes many harmful effects on human and animal lives. In developing countries many expensive synthetic drugs are being used to cure diseases but they have many side effects. Therefore, there is need to develop new strategies to control microbial infections. Therefore, we decided to work on extracts of different parts of Ficus carica which have good activity against gram positive bacteria, gram negative bacteria and fungal species. Methanol and chloroform extracts of root, stem, leaves and fruits were prepared and zone of inhibition was measured by using well diffusion method against gram negative bacteria (Escherichia coli, Pseudomonas aeruginosa) two gram positive bacteria (Staphylococcus aureus, Bacillus cereus) and two fungal species Aspergillus niger and Aspergillus oryzae. methanol extract of leaves has high % yield (5.86%) and high zone of inhibition (23mm) against bacteria Escherichia coli and fungus Aspergillus niger (34mm). Bacteria Staphylococcus aureus was highly sensitive to chloroform extract with zone of inhibition 74mm while Escherichia coli was highly sensitive to metabolic extract with zone of inhibition 82mm. Chloroform extract has average zone of inhibition (56mm) and methanolic extract has average zone of inhibition (63mm).


2011 ◽  
Vol 6 (2) ◽  
pp. 1934578X1100600 ◽  
Author(s):  
Sandra M. Bach ◽  
Mario A. Fortuna ◽  
Rodgoun Attarian ◽  
Juliana T. de Trimarco ◽  
César A. N. Catalán ◽  
...  

The antimicrobial and cytotoxic activities of chloroform extracts from the weeds Centaurea tweediei and C. diffusa, and the main sesquiterpene lactones isolated from these species, onopordopicrin and cnicin, respectively, were assayed. Results show that the chloroform extracts from both Centaurea species possess antibacterial activities against a panel of Gram-positive and Gram-negative bacteria. Remarkable antibacterial activity against methicillin-resistant Staphylococcus aureus was also measured. Both the extracts and the purified sesquiterpene lactones show high cytotoxicity against human-derived macrophages. Despite this cytotoxicity, C. diffusa chloroform extract and cnicin are attractive candidates for evaluation as antibiotics in topical preparations against skin-associated pathogens.


Microbiology ◽  
2005 ◽  
Vol 151 (7) ◽  
pp. 2331-2342 ◽  
Author(s):  
Marian Takáč ◽  
Angela Witte ◽  
Udo Bläsi

Double-stranded DNA phages of both Gram-positive and Gram-negative bacteria typically use a holin–endolysin system to achieve lysis of their host. In this study, the lysis genes of Staphylococcus aureus phage P68 were characterized. P68 gene lys16 was shown to encode a cell-wall-degrading enzyme, which causes cell lysis when externally added to clinical isolates of S. aureus. Another gene, hol15, was identified embedded in the −1 reading frame at the 3′ end of lys16. The deduced Hol15 protein has three putative transmembrane domains, and thus resembles class I holins. An additional candidate holin gene, hol12, was found downstream of the endolysin gene lys16 based on two predicted transmembrane domains of the encoded protein, which is a typical trait of class II holins. The synthesis of either Hol12 or Hol15 resulted in growth retardation of Escherichia coli, and both hol15 and hol12 were able to complement a phage λ Sam mutation. The hol15 gene has a dual start motif beginning with the codons Met1-Lys2-Met3…. Evidence is presented that the hol15 gene encodes a lysis inhibitor (anti-holin) and a lysis effector (actual holin). As depolarization of the membrane converted the anti-holin to a functional holin, these studies suggested that hol15 functions as a typical dual start motif class I holin. The unusual arrangement of the P68 lysis genes is discussed.


1988 ◽  
Vol 55 (4) ◽  
pp. 597-602 ◽  
Author(s):  
Lydia Bautista ◽  
Rohan G. Kroll

SummaryEffects of the addition of a proteinase (Neutrase 1–5S) and a peptidase (aminopeptidase DP-102) as agents for accelerating the ripening of Cheddar cheese on the survival of some non-starter bacteria (Staphylococcus aureus, Enterococcus faecalis, Escherichia coliand aSalmonellasp.) were studied throughout a 4-month ripening period. The enzymes were found to have no significant effect on the survival of the Gram-positive bacteria but some significant effects were observed, at some stages of the ripening period, with the Gram-negative bacteria in that lower levels were recovered from cheeses treated with the enzyme system.


2020 ◽  
Vol 73 (4) ◽  
Author(s):  
Courtney K Lawrence ◽  
Chris Sathianathan ◽  
Mauro Verrelli ◽  
Philippe Lagacé-Wiens ◽  
Robert Ariano ◽  
...  

Background: Given the morbidity and mortality associated with bloodstream infections in hemodialysis patients, understanding the microbiology is essential to optimizing treatment in this high-risk population.Objectives: To conduct a retrospective surveillance study of clinical blood isolates from adult hemodialysis patients, and to predict the microbiological coverage of empiric therapies for bloodstream infections in this population.Methods: Clinical blood isolate data were collected from the 4 main outpatient hemodialysis units in Winnipeg, Manitoba, from 2007 to 2014. The distribution of organisms and antimicrobial susceptibilities were characterized. When appropriate, changes over time were tested using time series analysis. Study data were used to predict and compare the microbiological coverage of various empiric therapies for bloodstream infections in hemodialysis patients.Results: The estimated annual number of patients receiving chronic hemodialysis increased steadily over the study period (p < 0.001), whereas the number of blood isolates increased initially, then decreased significantly, from 180 in 2011 to 93 in 2014 (p = 0.04). Gram-positive bacteria represented 72.6% (743/1024) of isolates, including Staphylococcus aureus (36.9%, 378/1024) and coagulase-negative staphylococci (23.1%, 237/1024). Only 26.1% (267/1024) of the isolates were gram-negative bacteria, the majority Enterobacteriaceae. The overall rate of methicillin resistance in S. aureus was 17.5%, and although annual rates were variable, there was a significant increase over time (p = 0.04). Antibiotic resistance in gram-negative bacteria was relatively low, except in Escherichia coli, where 13.5% and 16.2% of isolates were resistant to ceftriaxone and ciprofloxacin, respectively. Empiric therapy with vancomycin plus an agent for gram-negative coverage was predicted to cover 98.8% to 99.7% of blood isolates from hemodialysis patients, whereas cefazolin plus an agent for gram-negative coverage would cover only 67.5% to 68.4%.Conclusions: In an era of increasing antimicrobial resistance, data such as these and ongoing surveillance are essential components of antimicrobial stewardship in the hemodialysis population.Keywords: hemodialysis, microbiology, surveillance, resistance, antimicrobial stewardshipRÉSUMÉ Contexte : Étant donné la morbidité et la mortalité associées aux infections du sang parmi les patients en hémodialyse, la compréhension de la microbiologie est essentielle à l’optimisation du traitement de cette population exposée à un risque élevé.Objectifs : Mener une étude de surveillance rétrospective des isolats de sang cliniques des patients adultes en hémodialyse et prédire la couverture microbiologique des thérapies empiriques contre les infections du sang dans cette population.Méthodes : Les données relatives aux isolats de sang cliniques ont été recueillies dans les quatre unités ambulatoires principales d’hémodialyse à Winnipeg (Manitoba), entre 2007 et 2014. La caractérisation a porté sur la distribution des organismes et les susceptibilités aux antimicrobiens. L’évolution dans le temps a été testée au besoin à l’aide d’une analyse chronologique. Les données de l’étude ont permis de prédire et de comparer la couverture microbiologique de diverses thérapies empiriques contre les infections du sang pour les patients en hémodialyse.Résultats : On estime que le nombre annuel de patients recevant une hémodialyse chronique a augmenté régulièrement au cours de la période de l’étude (p < 0,001); le nombre d’isolats de sang a tout d’abord augmenté, puis il a grandement diminué : de 180 en 2011, il est passé à 93 en 2014 (p = 0,04). Les bactéries à Gram positif représentaient 72,6 % (743/1024) des isolats, y compris les Staphylococcus aureus (36,9 %, 378/1024) et les staphylocoques à coagulase négative (23,1 %, 237/1024). Seulement 26,1 % (267/1024) des isolats étaient des bactéries à Gram négatif, la majorité desquelles étant des Enterobacteriaceae. Le taux général de résistance à la méticilline de S. aureus était de 17,5 %, et bien que les taux annuels étaient variables, une augmentation importante a été observée avec le temps (p = 0,04). La résistance aux antibiotiques des bactéries à Gram négatif était relativement faible, sauf Escherichia coli, où respectivement 13,5 % et 16,2 % des isolats étaient résistants à la ceftriaxone et à la ciprofloxacine. On prévoyait que la thérapie empirique à la vancomycine associée à un agent pour la couverture à Gram positif couvrirait de 98,8 % à 99,7 % des isolats de sang des patients en hémodialyse, tandis que la céfazoline associée à un agent de la couverture à Gram négatif ne couvrirait que 67,5 % à 68,4 %.Conclusions : À une époque qui se caractérise par une augmentation de la résistance aux antimicrobiens, des données comme celles-ci et celles portant sur la surveillance continue sont des composantes essentielles de la bonne gestion de l’utilisation des antimicrobiens pour les patients adultes en hémodialyse.Mots-clés : hémodialyse, microbiologie, surveillance, résistance, gestion de l’utilisation des antimicrobiens


2021 ◽  
Author(s):  
Sanjay Ratan Kumavat ◽  
SATYENDRA MISHRA

Abstract Plants are emerging as a cost-effective and ecofriendly method for green synthesis of nanoparticles. The plant extract Launaea procumbens was used as a reduction agent in the green synthesis of silver nanoparticles. UV-Visible spectroscopy, HR-TEM, SAED, FE-SEM, EDAX, DLS, and FT-IR were used to study the green synthesized silver nanoparticles. UV-Vis spectroscopy of a prepared silver solution revealed maximum absorption at 435 nm. The synthesized silver nanoparticles were found to be spherical in shape with a size in the range of 24.28 to 31.54 nm. DLS analysis was used to determine the size of the green synthesized silver nanoparticles, which showed outstanding antibacterial action against Gram-positive bacteria Bacillus subtilis and Staphylococcus aureus, as well as Gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa. Gram-positive Bacillus subtilis had a maximum zone of inhibition of 20 mm, Staphylococcus aureus had a zone of inhibition of 19 mm, and Gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa had zones of inhibition of 13 mm.


2004 ◽  
Vol 24 (1) ◽  
pp. 65-67 ◽  
Author(s):  
Farshad Sepandj ◽  
Howard Ceri ◽  
Allan Gibb ◽  
Ronald Read ◽  
Merle Olson

Objective Minimum inhibitory concentration (MIC) and minimum biofilm eliminating concentration (MBEC) results were compared to determine changes in the pattern of antibiotic sensitivity of gram-negative bacilli from the planktonic to the biofilm phase of growth. Methodology The MIC and MBEC assays were conducted on stored isolates obtained from patients presenting with peritoneal dialysis-related gram-negative peritonitis with Escherichia coli or Pseudomonas. Results The antibiotic sensitivities of planktonic organisms tested by the MIC assays were significantly higher than the antibiotic sensitivities of the same organisms in their biofilm state, as tested by the MBEC assays. Conclusions In their biofilm state, gram-negative bacteria are much less susceptible to antibiotics compared to their antibiotic susceptibility in the planktonic state.


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Paulina L. Páez ◽  
Claudia M. Bazán ◽  
María E. Bongiovanni ◽  
Judith Toneatto ◽  
Inés Albesa ◽  
...  

The prevalence of antibiotic resistance has resulted in the need for new approaches to be developed to combat previously easily treatable infections. The main aim of this work was to establish the potential of the syntheticα-diimine chromium(III) and ruthenium(II) complexes (where theα-diimine ligands are bpy = 2,2-bipyridine, phen = 1,10-phenanthroline, and dppz = dipyrido[3,2-a:2′,3′-c]-phenazine) like [Cr(phen)3]3+, [Cr(phen)2(dppz)]3+, [Ru(phen)3]2+, and [Ru(bpy)3]2+as antibacterial agents by generating oxidative stress. The [Cr(phen)3]3+and [Cr(phen)2(dppz)]3+complexes showed activity against Gram positive and Gram negative bacteria with minimum inhibitory concentrations (MICs) ranging from 0.125 μg/mL to 1 μg/mL, while [Ru(phen)3]2+and [Ru(bpy)3]2+do not exhibit antimicrobial activity against the two bacterial genera studied at the concentration range used. When ciprofloxacin was combined with [Cr(phen)3]3+for the inhibition ofStaphylococcus aureusandEscherichia coli, an important synergistic effect was observed, FIC 0.066 forS. aureusand FIC 0.064 forE. coli. The work described here shows that chromium(III) complexes are bactericidal forS. aureusandE. coli. Our results indicate thatα-diimine chromium(III) complexes may be interesting to open new paths for metallodrug chemotherapy against different bacterial genera since some of these complexes have been found to exhibit remarkable antibacterial activities.


2018 ◽  
Vol 25 (1) ◽  
pp. 3-15 ◽  
Author(s):  
Yu Wu ◽  
Yu-gang Shi ◽  
Lu-yao Zeng ◽  
Ying Pan ◽  
Xin-ying Huang ◽  
...  

Although the antimicrobial properties of kojic acid have been recognized, the subcellular mechanism of bacterial inactivation caused by it has never been clearly elucidated. In the present study, the antibacterial and anti-biofilm activity of kojic acid was evaluated against five foodborne pathogens including Listeria monocytogenes, Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Salmonella typhimurium. The antibacterial activity was determined by minimum inhibitory concentration, minimum bactericidal concentration, and the time-kill assay. Among them, the susceptibility of Escherichia coli was significant with the lowest minimum inhibitory concentration and minimum bactericidal concentration values of 10 and 20 mM, respectively. Subcellular mechanism of bacterial inactivation related to kojic acid was revealed through comprehensive factors including cell morphology, membrane permeability, K+ leakage, zeta potential, intracellular enzyme, and DNA assay. Results demonstrated that bacterial inactivation caused by kojic acid, especially for Gram-negative bacteria, was primarily induced by the pronounced damage to the cell membrane integrity. Leakage of intracellular enzyme to the supernatants implied that the cell membrane permeability was compromised. Consequently, the release of K+ from the cytosol leads to the alterations of the zeta potential of cells, which would disturb the subcellular localization of some proteins and thereby cause the bacterial inactivation. The free −CH2OH group at the C-2 of kojic acid could play more significant role in the antimicrobial performance of kojic acid against Gram-negative bacteria. Moreover, remarkable interaction with DNA was also observed. Kojic acid at sub-minimum inhibitory concentration inhibited biofilm formation by these bacteria.


2018 ◽  
Vol 24 (6) ◽  
pp. 327-332 ◽  
Author(s):  
Yogesh D. Mane ◽  
Smita S. Patil ◽  
Dhanraj O. Biradar ◽  
Bhimrao C. Khade

Abstract Ten 5-bromoindole-2-carboxamides were synthesized, characterized and evaluated for antibacterial activity against pathogenic Gram-negative bacteria Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa and Salmonella Typhi using gentamicin and ciprofloxacin as internal standards. Compounds 7a–c, 7g and 7h exhibit high antibacterial activity with a minimum inhibitory concentration (MIC) of 0.35–1.25 μg/mL. Compounds 7a–c exhibit antibacterial activities that are higher than those of the standards against E. coli and P. aeruginosa.


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