scholarly journals Extracellular vesicles: An emerging platform in gram-positive bacteria

2020 ◽  
Vol 7 (12) ◽  
pp. 312-322
Author(s):  
Swagata Bose ◽  
Shifu Aggarwal ◽  
Durg Vijai Singh ◽  
Narottam Acharya
Keyword(s):  
Extracellular Vesicles ◽  
Intercellular Communication ◽  
Pathogenic Bacteria ◽  
Membrane Vesicles ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Functional Aspects ◽  
As Stress

Extracellular vesicles (EV), also known as membrane vesicles, are produced as an end product of secretion by both pathogenic and non-pathogenic bacteria. Several reports suggest that archaea, gram-negative bacteria, and eukaryotic cells secrete membrane vesicles as a means for cell-free intercellular communication. EVs influence intercellular communication by transferring a myriad of biomolecules including genetic information. Also, EVs have been implicated in many phenomena such as stress response, intercellular competition, lateral gene transfer, and pathogenicity. However, the cellular process of secreting EVs in gram-positive bacteria is less studied. A notion with the thick cell-walled microbes such as gram-positive bacteria is that the EV release is impossible among them. The role of gram-positive EVs in health and diseases is being studied gradually. Being nano-sized, the EVs from gram-positive bacteria carry a diversity of cargo compounds that have a role in bacterial competition, survival, invasion, host immune evasion, and infection. In this review, we summarise the current understanding of the EVs produced by gram-positive bacteria. Also, we discuss the functional aspects of these components while comparing them with gram-negative bacteria.

scholarly journals Antimicrobial Activity of Gardenia jasminoides Callus and Crude Leaf Extracts for some Organic Solvents against some Pathogenic Bacteria and Yeasts

2014 ◽  
Vol 8 (3) ◽  
pp. 40-45
Author(s):  
Zina Hashem Shehab ◽  
Huda Suhail Abid ◽  
Sumaya Fadhil Hamad ◽  
Sara Haitham
Keyword(s):  
Staphylococcus Aureus ◽  
Candida Albicans ◽  
Pathogenic Bacteria ◽  
Saccharomyces Boulardii ◽  
Gram Negative Bacteria ◽  
Proteus Vulgaris ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Gardenia Jasminoides

The study was conducted to evaluate the inhibitory activity of methanol extract of Gardenia jasminoides leaves compared with leaf crude extracts for some organic solvents namely Methanol, Ethanol, Petroleum ether, Asetone and Chloroform on growth of some pathogenic bacteria and yeast, which included four gram positive isolates Staphylococcus aureus, Enterococcus faecalis, Streptococcus pyogenes and Bacillus cereus and gram negative isolates Escherichia coli, Salmonella typhi, Proteus vulgaris and Pseudomonas aeruginosa and some yeasts Candida albicans and Saccharomyces boulardii, by using well diffusion method. The inhibitory activity of extracts in the tested bacterial strains and yeasts was varied according to the type of extracting solvents and are tested microorganisms. The methanol callus extract which grown on Murashige and Skoog (MS) media by using (Naphthalen acitic acid) NAA and (Benzyle adenine) BA as growth regulator highly effective as compared to the other extracts as for inhibition of three gram positive bacteria and three gram negative bacteria,which include Staphylococcus aureus and, Proteus vulgaris, followed by acetone and ethanolic extracts which include two gram positive bacteria and two gram negative bacteria. All extracts had highly effect in growth of Candida albicans while all crude extracts didn’t show any sensitivity against Saccharomyces boulardii, and when we’d done (High Performance Liquid Chromatography) HPLC test for detection of some active compound we found Quinic acid, Iridiods glycosides and Crocin which its rate in fresh callus was higher than fresh leaves.

scholarly journals Bactericidal effects of non-thermal argon plasma in vitro, in biofilms and in the animal model of infected wounds

2011 ◽  
Vol 60 (1) ◽  
pp. 75-83 ◽  
Author(s):  
Svetlana A. Ermolaeva ◽  
Alexander F. Varfolomeev ◽  
Marina Yu. Chernukha ◽  
Dmitry S. Yurov ◽  
Mikhail M. Vasiliev ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Plasma Treatment ◽  
Pathogenic Bacteria ◽  
Argon Plasma ◽  
Burkholderia Cenocepacia ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Plasma Treatments

Non-thermal (low-temperature) physical plasma is under intensive study as an alternative approach to control superficial wound and skin infections when the effectiveness of chemical agents is weak due to natural pathogen or biofilm resistance. The purpose of this study was to test the individual susceptibility of pathogenic bacteria to non-thermal argon plasma and to measure the effectiveness of plasma treatments against bacteria in biofilms and on wound surfaces. Overall, Gram-negative bacteria were more susceptible to plasma treatment than Gram-positive bacteria. For the Gram-negative bacteria Pseudomonas aeruginosa, Burkholderia cenocepacia and Escherichia coli, there were no survivors among the initial 105 c.f.u. after a 5 min plasma treatment. The susceptibility of Gram-positive bacteria was species- and strain-specific. Streptococcus pyogenes was the most resistant with 17 % survival of the initial 105 c.f.u. after a 5 min plasma treatment. Staphylococcus aureus had a strain-dependent resistance with 0 and 10 % survival from 105 c.f.u. of the Sa 78 and ATCC 6538 strains, respectively. Staphylococcus epidermidis and Enterococcus faecium had medium resistance. Non-ionized argon gas was not bactericidal. Biofilms partly protected bacteria, with the efficiency of protection dependent on biofilm thickness. Bacteria in deeper biofilm layers survived better after the plasma treatment. A rat model of a superficial slash wound infected with P. aeruginosa and the plasma-sensitive Staphylococcus aureus strain Sa 78 was used to assess the efficiency of argon plasma treatment. A 10 min treatment significantly reduced bacterial loads on the wound surface. A 5-day course of daily plasma treatments eliminated P. aeruginosa from the plasma-treated animals 2 days earlier than from the control ones. A statistically significant increase in the rate of wound closure was observed in plasma-treated animals after the third day of the course. Wound healing in plasma-treated animals slowed down after the course had been completed. Overall, the results show considerable potential for non-thermal argon plasma in eliminating pathogenic bacteria from biofilms and wound surfaces.

scholarly journals Potential Assessment of Rumex spp. as a Source of Bioactive Compounds and Biological Activity

2021 ◽  
Vol 12 (2) ◽  
pp. 1824-1834
Keyword(s):  
Antioxidant Activity ◽  
Broad Spectrum ◽  
Pathogenic Bacteria ◽  
Gram Negative Bacteria ◽  
Meoh Extract ◽  
Gram Positive ◽  
Filter Paper Disc ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Antibacterial Performance

Secondary metabolites from the shoots and roots of three Rumex species collected from three different habitats were investigated (Rumex dentatus collected from cultivated land, R. pictus collected from the coastal desert and R. vesicarius collected from the inland desert) and tested for antioxidant activity as well as for anti-microbial activity against some human pathogenic bacteria. The present study indicated that the quantitative analysis of shoot and root extracts of three Rumex spp. were found to be rich in tannins and phenolics composition. The aerial parts of the three plants exhibited the highest significant values compared to the root parts. The MeOH extracts of Rumex species showed adequate antioxidant activity, wherein the IC50 values of the MeOH from the cultivated sample was 41.61 and 31.31 mg mL-1, coastal samples were 34.99 and 23.99 mg mL-1, while the sample of inland showed IC50 value of 41.59 and 31.67 mg mL-1, for root and shoot, respectively. Furthermore, using a filter paper disc assay, the MeOH extracts of the three Rumex species showed a substantial anti-microbial inhibitory effect on the growth of 10 pathogenic bacteria. According to sensitivity, the tested organisms could be sequenced as following: E. coli < K. pneumoniae ˂ S. typhi < P. aeruginosa for Gram-negative bacteria and B. subtilis < S. pneumoniae ˂ L. monocytoyenes < S. epidermis < S. aureus < B. cereus for Gram-positive bacteria. In addition, the antibacterial performance of R. dentatus root and R. vesicarius shoot MeOH extract is 100% broad spectrum against Gram-negative bacteria. A shoot of R. dentatus and R. pictus MeOH extract against Gram-positive bacteria is 83.3% broad spectrum. A further study is recommended for more characterization of the major compounds and assesses their efficiency and biosafety.

scholarly journals DETERMINATION OF ANTIBACTERIAL ACTIVITY OF SOME IMPORTANT SPICES

2015 ◽  
Vol 3 (10) ◽  
pp. 57-64
Author(s):  
Ranganathan Kapilan
Keyword(s):  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Pathogenic Bacteria ◽  
Maximum Activity ◽  
Gram Negative Bacteria ◽  
Alcoholic Extract ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Wide Range

Wide range of plant extracts are used for medicinal purposes as they are very cheap, efficient, harmless and do not cause any side effects. Spices are parts of different plants and they add special aroma and taste to the food preparations. The aim of the study was to determine the antimicrobial activity of some important naturally grown spices against gram positive and gram negative pathogenic bacteria. Antibacterial activity of the spices was tested against gram positive bacteria Bacillus pumilus, Bacillus cereus and Staphylococcus aureus and gram negative bacteria Escherichia coli, Salmonella typhi and Pseudomonas aeruginosa using aqueous, ethanolic, methanolic and liquid nutrient extracts. Among all the extracts tested alcoholic extracts of Cardamom (Elettaria cardamom), clove (Eugenia caryophyllus) and lemongrass (Cymbopogoncitratus) showed maximum antimicrobial activity against gram negative bacteria while alcoholic extract of Cardamom (Elettaria cardamom) and lemongrass (Cymbopogoncitratus) showed maximum activity against gram positive bacteria. All the spices tested in this study proved that they have antibacterial activity and the maximum activity index (1.39) was exhibited by the ethanol extract of cardamom against E.coli.

scholarly journals The antimicrobial spectra of selected Penicillia against some pathogenic bacteria and yeasts

2014 ◽  
Vol 19 (1) ◽  
pp. 111-114
Author(s):  
Shashi Chauhan ◽  
R. K. Chauhan
Keyword(s):  
Pathogenic Bacteria ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Pathogenic Organisms

The antagonista activity of eight isolaies of penicillia bas been studied against 13 pathogenic organisms, which included 6 Gram-positive bacteria, 4 Gram-negative bacteria and 3 yeasts.

scholarly journals Answers to naysayers regarding microbial extracellular vesicles

2019 ◽  
Vol 47 (4) ◽  
pp. 1005-1012 ◽  
Author(s):  
Carolina Coelho ◽  
Arturo Casadevall
Keyword(s):  
Cell Wall ◽  
Extracellular Vesicles ◽  
Living Cell ◽  
Physiological Function ◽  
Biological Significance ◽  
Gram Negative Bacteria ◽  
Biological Processes ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

Abstract It is now over 30 years since the discovery of extracellular vesicles (EVs) in Gram-negative bacteria. However, for cell-walled microbes such as fungi, mycobacteria and Gram-positive bacteria it was thought that EV release would be impossible, since such structures were not believed to cross the thick cell wall. This notion was disproven 10 years ago with the discovery of EVs in fungi, mycobacteria, and gram-positive bacteria. Today, EVs have been described in practically every species tested, ranging from Fungi through Bacteria and Archaea, suggesting that EVs are a feature of every living cell. However, there continues to be skepticism in some quarters regarding EV release and their biological significance. In this review, we list doubts that have been verbalized to us and provide answers to counter them. In our opinion, there is no doubt as to existence and physiological function of EVs and we take this opportunity to highlight the most pressing topics in our understanding of the biological processes underlying these structures.

scholarly journals Strain specificity in antimicrobial activity of non-thermal plasma

2019 ◽  
Vol 11 (20) ◽  
pp. 110-115
Author(s):  
Hammad R. Humud
Keyword(s):  
Staphylococcus Aureus ◽  
Plasma Treatment ◽  
Pathogenic Bacteria ◽  
Argon Plasma ◽  
Gram Negative Bacteria ◽  
Strain Specificity ◽  
Gram Positive ◽  
Temperature Plasma ◽  
Gram Negative ◽  
Gram Positive Bacteria

Non-thermal (low-temperature) plasma may act as an alternative approach to control superficial wound and skin infections when the effectiveness of chemical agents is weak due to natural pathogen or biofilm resistance. In this paper an atmospheric pressure plasma needle jet device which generates a cold plasma jet is used to measure the effectiveness of plasma treatment against different pathogenic bacteria and to test the individual susceptibility of pathogenic bacteria to non-thermal argon plasma. It is found that, Gram-negative bacteria were more susceptible to plasma treatment than Gram-positive bacteria. For the Gram-negative bacteria Pseudomonas aeruginosa, there were no survivors among the initial 1x108C.F.U (Colony Forming Unit) after a 40 seconds plasma treatment. The susceptibility of Gram-positive bacteria and the Gram-negative bacteria were species and strain specific. Staphylococcus aureus was the most resistant with 4.5 % survival of the initial 2x106C.F.U. after a 40 seconds plasma treatment. According to species, Staphylococcus aureus had a strain-dependent resistance with 39% and 99% reduction from 2x106C.F.U.of the five studied isolates, respectively, whereas, Escherichia coli had a lower resistance with 76% and 99% reduction after 40 seconds.

scholarly journals Test for the antibacterial inhibition of kaffir lime leaf (Citrus hysteric D.C) extract against pathogen bacteria in improving food safety

2021 ◽  
Vol 883 (1) ◽  
pp. 012056
Author(s):  
S J Nendissa ◽  
D M Nendissa
Keyword(s):  
Antibacterial Activity ◽  
Food Safety ◽  
Salmonella Typhimurium ◽  
Pathogenic Bacteria ◽  
Leaf Extract ◽  
Diffusion Method ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

Abstract Kafir lime leaf (Citrus hystrix) is a plant from the citrus tribe that has long been known by community as flavor ingredient. To support its use and increase its application in supporting food safety, a test the inhibition of on kaffir lime leaf extract against pathogenic bacteria, namely Gram Negative Bacteria (Escherichia coli, Salmonella typhimurium) and Gram Positive bacteria (Staphylococcus aereus, P. aeroginosa). Making kaffir lime leaf extract (Citrus hystrix) was done by weighing 150g of lime leaf powder, then immersing in 96% ethanol solution and leaving for + 3 days. Kaffir lime leaf extract was dissolved with sterile distilled aquades to obtain a concentration of 5%, 10% and 15%. The antibacterial activity of kaffir lime leaf extract was tested by diffusion method using disc paper to determine of the bacterial growth inhibition area. The results showed that kaffir lime extract had antibacterial activity inhibition of 12,78 mm of S. aereus, 9 mm of E.coli, 7,12 mm of S. typhimurium and 9,3 mm of P. aeroginosa. Kaffir lime leaf extract has inhibition effectiveness for gram positive bacteria Staphylococcus aereus and gram negative bacteria E. coli, Salmonella typhimurium, P. aeroginosa. Thus, kaffir lime leaf extract can be used as a decontaminant agait theses 4 type of bacteria, especially Staphylococcus aereus which has a strong inhibitory power, so it can maintain quality and increase the safety of mead based foods

scholarly journals Distribution and Drug Sensitivity of Pathogenic Bacteria in Diabetic Foot Ulcer Patients With Necrotizing Fasciitis at a Diabetic Foot Center in China

2021 ◽  
Author(s):  
Xuemei Li ◽  
Zhipeng Du ◽  
Ziwei Tang ◽  
Qin Wen ◽  
Qingfeng Cheng ◽  
...  
Keyword(s):  
Diabetic Foot ◽  
Pathogenic Bacteria ◽  
Drug Sensitivity ◽  
Foot Ulcer ◽  
Diabetic Foot Ulcer ◽  
Gram Negative Bacteria ◽  
Bacterial Strains ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

Abstract Background: When a diabetic foot ulcer (DFU) is complicated by necrotizing fasciitis (DNF), this may increase the risk for amputation and mortality, making DNF treatment more complicated, and may eventually lead to amputation and mortality. DNF treatment must include the appropriate antibiotic intervention. However, studies on the distribution and drug sensitivity of pathogenic bacteria in DNF patients remain lacking. This study investigated the distribution and susceptibility of pathogenic bacteria in DNF patients, and provides empirical antibacterial guidance for the clinic.Methods: In a single diabetic foot center, the results from microbial cultures and drug susceptibility tests of patients with DNF from October 2013 to December 2020 were collected and analyzed.Results: A total of 101 DNF patients were included in this study, of whom 94 had positive culture test results. A total of 124 pathogens were cultured, including 76 Gram-positive bacterial strains, 42 Gram-negative bacterial strains, and six fungal strains. Polymicrobial infections accounted for 26.7% and monomicrobial infections accounted for 66.3%. Staphylococcus aureus was the most common bacterium isolated, followed by Enterococcus faecalis and Streptococcus agalactiae. Pseudomonas aeruginosa, Klebsiella pneumoniae, and Proteus mirabilis were the most common Gram-negative bacteria. Thirty-five strains of multi-drug resistant (MDR) bacteria were isolated, representing 28.2% of the total isolates. Gram-positive bacteria were more sensitive to levofloxacin, moxifloxacin, vancomycin, teicoplanin, tigecycline, and linezolid, while Gram-negative bacteria were more sensitive to amikacin, piperacillin/tazobactam, cefoperazone/sulbactam, ceftazidime, cefepime, imipenem, and meropenem. Conclusions: Gram-positive bacteria were the main bacteria isolated from DNF patients. The bacterial composition, the proportion of MDR bacteria among the pathogens, and high risk for amputation should be fully considered in the initial empirical medication, and broad-spectrum antibacterials are recommended.

Rapid demonstration of septic or infectious arthritis due to Gram-negative bacteria

1992 ◽  
Vol 50 (1) ◽  
pp. 686-687
Author(s):  
Jacob S. Hanker ◽  
Paul R. Gross ◽  
Beverly L. Giammara
Keyword(s):  
Chronic Arthritis ◽  
Blood Cultures ◽  
Gram Negative Bacteria ◽  
Infectious Arthritis ◽  
Bacterial Arthritis ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

Blood cultures are positive in approximately only 50 per cent of the patients with nongonococcal bacterial infectious arthritis and about 20 per cent of those with gonococcal arthritis. But the concept that gram-negative bacteria could be involved even in chronic arthritis is well-supported. Gram stains are more definitive in staphylococcal arthritis caused by gram-positive bacteria than in bacterial arthritis due to gram-negative bacteria. In the latter situation where gram-negative bacilli are the problem, Gram stains are helpful for 50% of the patients; they are only helpful for 25% of the patients, however, where gram-negative gonococci are the problem. In arthritis due to gram-positive Staphylococci. Gramstained smears are positive for 75% of the patients.

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