scholarly journals Filamentous Phage Active on the Gram-Positive Bacterium Propionibacterium freudenreichii

2002 ◽  
Vol 184 (7) ◽  
pp. 2030-2033 ◽  
Author(s):  
Marie-Christine Chopin ◽  
Annette Rouault ◽  
S. Dusko Ehrlich ◽  
Michel Gautier
Keyword(s):  
Filamentous Phage ◽  
Gram Negative Bacteria ◽  
Coat Proteins ◽  
Propionibacterium Freudenreichii ◽  
Positive Bacterium ◽  
Gram Positive ◽  
Gram Negative ◽  
A Genome ◽  
Putative Coat Protein ◽  
Filamentous Phages

ABSTRACT We present the first description of a single-stranded DNA filamentous phage able to replicate in a gram-positive bacterium. Phage B5 infects Propionibacterium freudenreichii and has a genome consisting of 5,806 bases coding for 10 putative open reading frames. The organization of the genome is very similar to the organization of the genomes of filamentous phages active on gram-negative bacteria. The putative coat protein exhibits homology with the coat proteins of phages PH75 and Pf3 active on Thermus thermophilus and Pseudomonas aeruginosa, respectively. B5 is, therefore, evolutionarily related to the filamentous phages active on gram-negative bacteria.

scholarly journals Long-distance electron transfer in a filamentous Gram-positive bacterium

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yonggang Yang ◽  
Zegao Wang ◽  
Cuifen Gan ◽  
Lasse Hyldgaard Klausen ◽  
Robin Bonné ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Microbial Fuel Cells ◽  
Extracellular Electron Transfer ◽  
Gram Negative Bacteria ◽  
Positive Bacterium ◽  
Long Distance ◽  
Gram Positive ◽  
Gram Negative ◽  
Force Microscopy ◽  
Cell Envelopes

AbstractLong-distance extracellular electron transfer has been observed in Gram-negative bacteria and plays roles in both natural and engineering processes. The electron transfer can be mediated by conductive protein appendages (in short unicellular bacteria such as Geobacter species) or by conductive cell envelopes (in filamentous multicellular cable bacteria). Here we show that Lysinibacillus varians GY32, a filamentous unicellular Gram-positive bacterium, is capable of bidirectional extracellular electron transfer. In microbial fuel cells, L. varians can form centimetre-range conductive cellular networks and, when grown on graphite electrodes, the cells can reach a remarkable length of 1.08 mm. Atomic force microscopy and microelectrode analyses suggest that the conductivity is linked to pili-like protein appendages. Our results show that long-distance electron transfer is not limited to Gram-negative bacteria.

scholarly journals Structural characterisation of a Fic protein from Clostridium difficile

2014 ◽  
Vol 70 (a1) ◽  
pp. C814-C814
Author(s):  
Ditte Welner ◽  
Emil Dedic ◽  
Hans van Leeuwen ◽  
Ed Kuijper ◽  
Rene Jorgensen ◽  
...  
Keyword(s):  
Clostridium Difficile ◽  
Target Identification ◽  
Current Status ◽  
Gram Negative Bacteria ◽  
Post Translational Modification ◽  
Positive Bacterium ◽  
Gram Positive ◽  
Gram Negative ◽  
Structural Characterisation ◽  
Atp Binding Protein

Fic domains in proteins are found in abundance in nature from the simplest prokaryotes to animals. Interestingly, Fic domains found in two virulence factors of gram-negative bacteria have recently been demonstrated to catalyse the transfer of an AMP moiety from ATP to small host GTPases (1,2). This post-translational modification has received considerable interest and a role for adenylylation in pathology and physiology is emerging. We have structurally characterised a newly identified Fic protein of the pathogenic gram-positive bacterium Clostridium difficile. A constitutively active inhibitory helix mutant of C. difficile Fic was purified, crystallised and data collected to 1.7 Å resolution. The structure confirms C. difficult Fic protein as an ATP binding protein and reveal a binding site similar to other confirmed virulent Fic proteins. Surprisingly, this gram-positive Fic protein does not seem to target GTPases in humans and currently target identification is being chased. The current status of the project will be presented.

scholarly journals Chemical Composition, Olfactory Evaluation and Antimicrobial Activities of Jasminum grandiflorum L. Absolute from India

2007 ◽  
Vol 2 (4) ◽  
pp. 1934578X0700200 ◽  
Author(s):  
Leopold Jirovetz ◽  
Gerhard Buchbauer ◽  
Thomas Schweiger ◽  
Zapriana Denkova ◽  
Alexander Slavchev ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Chemical Composition ◽  
Antimicrobial Activities ◽  
Biological Data ◽  
Gram Negative Bacteria ◽  
Positive Bacterium ◽  
Gram Positive ◽  
Gram Negative ◽  
Agar Dilution ◽  
Minor Compounds

The chemical composition of a sample of Jasminum grandiflorum L. absolute from India was analyzed by GC and GC/MS. The major compounds identified were benzyl acetate (23.7%), benzyl benzoate (20.7%), phytol (10.9%), linalool (8.2%), isophytol (5.5%), geranyl linalool (3.0%), methyl linoleate (2.8%) and eugenol (2.5%). The odor of this absolute sample was olfactorically evaluated as intense and heavy floral-flowery, with penetrant-animalic and fruity side-notes. Some main and minor compounds were found to be responsible for the aroma impression of this sample. The antimicrobial activities of the J. grandiflorum sample and of some of its main and minor compounds were tested against Gram-positive and Gram-negative bacteria, as well as against the yeast Candida albicans, using agar dilution and agar diffusion methods. The jasmine absolute showed medium to high activity (reference compounds: eugenol and three synthetic antibiotics) against the Gram-positive bacterium Enterococcus faecalis, against the Gram-negative bacteria Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae and Salmonella sp., as well as against the yeast Candida albicans. A comparison of these biological data with those of some constituents of the jasmine absolute is also given.

scholarly journals Identification of a d-Arabinose-5-Phosphate Isomerase in the Gram-Positive Clostridium tetani

2017 ◽  
Vol 199 (17) ◽  
Author(s):  
David L. Cech ◽  
Katherine Markin ◽  
Ronald W. Woodard
Keyword(s):  
Sequence Similarity ◽  
Physiological Role ◽  
Gram Negative Bacteria ◽  
Positive Bacterium ◽  
Gram Positive ◽  
Clostridium Tetani ◽  
High Sequence Similarity ◽  
Gram Negative ◽  
Content Type ◽  
Sugar Phosphates

ABSTRACT d-Arabinose-5-phosphate (A5P) isomerases (APIs) catalyze the interconversion of d-ribulose-5-phosphate and d-arabinose-5-phosphate. Various Gram-negative bacteria, such as the uropathogenic Escherichia coli strain CFT073, contain multiple API paralogs (KdsD, GutQ, KpsF, and c3406) that have been assigned various cellular functions. The d-arabinose-5-phosphate formed by these enzymes seems to play important roles in the biosynthesis of lipopolysaccharide (LPS) and group 2 K-antigen capsules, as well as in the regulation of the cellular d-glucitol uptake and uropathogenic infectivity/virulence. The genome of a Gram-positive pathogenic bacterium, Clostridium tetani, contains a gene encoding a putative API, C. tetani API (CtAPI), even though C. tetani lacks both LPS and capsid biosynthetic genes. To better understand the physiological role of d-arabinose-5-phosphate in this Gram-positive organism, recombinant CtAPI was purified and characterized. CtAPI displays biochemical characteristics similar to those of APIs from Gram-negative organisms and complements the API deficiency of an E. coli API knockout strain. Thus, CtAPI represents the first d-arabinose-5-phosphate isomerase to be identified and characterized from a Gram-positive bacterium. IMPORTANCE The genome of Clostridium tetani, a pathogenic Gram-positive bacterium and the causative agent of tetanus, contains a gene (the CtAPI gene) that shares high sequence similarity with those of genes encoding d-arabinose-5-phosphate isomerases. APIs play an important role within Gram-negative bacteria in d-arabinose-5-phosphate production for lipopolysaccharide biosynthesis, capsule formation, and regulation of cellular d-glucitol uptake. The significance of our research is in identifying and characterizing CtAPI, the first Gram-positive API. Our findings show that CtAPI is specific to the interconversion of arabinose-5-phosphate and ribulose-5-phosphate while having no activity with the other sugars and sugar phosphates tested. We have speculated a regulatory role for this API in C. tetani, an organism that does not produce lipopolysaccharide.

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.

In-vitro Antioxidant and Antibacterial Activity of Methanolic Extract of Shorea robusta Gaertn. F. Resin

2016 ◽  
Vol 6 (4) ◽  
pp. 68
Author(s):  
Sushma Vashisht ◽  
Manish Pal Singh ◽  
Viney Chawla
Keyword(s):  
Antibacterial Activity ◽  
Methanolic Extract ◽  
Diffusion Method ◽  
Gram Negative Bacteria ◽  
Disc Diffusion ◽  
Gram Positive ◽  
Gram Negative ◽  
Shorea Robusta ◽  
Dose Dependent ◽  
Resin Extract

The methanolic extract of the resin of Shorea robusta was subjected to investigate its antioxidant and antibacterial properties its utility in free radical mediated diseases including diabetic, cardiovascular, cancer etc. The methanol extract of the resin was tested for antioxidant activity using scavenging activity of DPPH (1,1-diphenyl-2-picrylhydrazil) radical method, reducing power by FeCl3 and antibacterial activity against gram positive and gram negative bacteria using disc diffusion method. The phytochemical screening considered the presence of triterpenoids, tannins and flavoniods. Overall, the plant extract is a source of natural antioxidants which might be helpful in preventing the progress of various oxidative stress mediated diseases including aging. The half inhibition concentration (IC50) of resin extract of Shorea robusta and ascorbic acid were 35.60 µg/ml and 31.91 µg/ml respectively. The resin extract exhibit a significant dose dependent inhibition of DPPH activity. Antibacterial activity was observed against gram positive and gram negative bacteria in dose dependent manner.Key Words: Shorea robusta, antioxidant, antibacterial, Disc-diffusion, DPPH.

Antibacterial activity of magnesium oxide nanoparticles prepared by Calcination method

2019 ◽  
Vol 10 (03) ◽  
Author(s):  
Elaf Ayad Kadhem ◽  
Miaad Hamzah Zghair ◽  
Sarah , Hussam H. Tizkam, Shoeb Alahmad Salih Mahdi ◽  
Hussam H. Tizkam ◽  
Shoeb Alahmad
Keyword(s):  
Antibacterial Activity ◽  
Magnesium Oxide ◽  
Diffusion Method ◽  
Oxide Nanoparticles ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Magnesium Oxide Nanoparticles ◽  
Agar Disc

magnesium oxide nanoparticles (MgO NPs) were prepared by simple wet chemical method using different calcination temperatures. The prepared NPs were characterized by Electrostatic Discharge (ESD), Scanning Electron Microscope (SEM) and X-ray Diffraction (XRD). It demonstrates sharp intensive peak with the increase of crystallinty and increase of the size with varying morphologies with respect to increase of calcination temperature. Antibacterial studies were done on gram negative bacteria (E.coli) and gram positive bacteria (S.aureus) by agar disc diffusion method. The zones of inhibitions were found larger for gram positive bacteria than gram negative bacteria, this mean, antibacterial MgO NPs activity more active on gram positive bacteria than gram negative bacteria because of the structural differences. It was found that antibacterial activity of MgO NPs was found it has directly proportional with their concentration.

Antimicrobial Activity of Iron-Halide Complexes Against Gram-Positive and Gram-Negative Bacteria

2020 ◽  
Author(s):  
Nusrat Abedin ◽  
Abdullah Hamed A Alshehri ◽  
Ali M A Almughrbi ◽  
Olivia Moore ◽  
Sheikh Alyza ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Antimicrobial Resistance ◽  
Extracellular Dna ◽  
Antibiofilm Activity ◽  
Gram Negative Bacteria ◽  
Bacterial Strains ◽  
Gram Positive ◽  
Gram Negative ◽  
Antimicrobial Substances ◽  
Mammalian Cell Lines

Antimicrobial resistance (AMR) has become one of the more serious threats to the global health. The emergence of bacteria resistant to antimicrobial substances decreases the potencies of current antibiotics. Consequently, there is an urgent and growing need for the developing of new classes of antibiotics. Three prepared novel iron complexes have a broad-spectrum antimicrobial activity with minimum bactericidal concentration (MBC) values ranging from 3.5 to 10 mM and 3.5 to 40 mM against Gram-positive and Gram-negative bacteria with antimicrobial resistance phenotype, respectively. Time-kill studies and quantification of the extracellular DNA confirmed the bacteriolytic mode of action of the iron-halide compounds. Additionally, the novel complexes showed significant antibiofilm activity against the tested pathogenic bacterial strains at concentrations lower than the MBC. The cytotoxic effect of the complexes on different mammalian cell lines show sub-cytotoxic values at concentrations lower than the minimum bactericidal concentrations.

BAKTERI PADA KARANG SCLERACTINIA DI KAWASAN PERAIRAN BUNAKEN, MOROTAI DAN RAJA AMPAT

2020 ◽  
Vol 8 (1) ◽  
pp. 122
Author(s):  
Eghbert Eghbert Elvan Eghbert Elvan Ampou ◽  
Iis Iis Triyulianti ◽  
Nuryani Widagti ◽  
Suciadi Catur Nugroho ◽  
Yuli Pancawati
Keyword(s):  
Scleractinian Coral ◽  
Gram Negative Bacteria ◽  
Hard Coral ◽  
Field Sampling ◽  
Bacterial Isolation ◽  
Gram Positive ◽  
Coral Mucus ◽  
Gram Negative ◽  
Gram Positive Bacteria

Research on hard coral (Scleractinian coral) contaminated with bacteria is still not much done, especially in Indonesian waters. This study took samples of coral mucus in 2010 at 3 (three) different locations, namely Bunaken (May); Morotai (September) and Raja Ampat (November), which focused on the analysis of Research on hard coral (Scleractinian coral) contaminated with bacteria is still not much done, especially in Indonesian waters. This study took samples of coral mucus in 2010 at 3 (three) different locations, namely Bunaken (May); Morotai (September) and Raja Ampat (November), which focused on the analysis of gram-positive and gram-negative bacteria. The method used for field sampling is time swim, which is by diving at a depth of 5-10 meters for ± 30 minutes and randomly taking samples of coral mucus using siring or by taking directly on corals (reef branching). Mucus samples were analyzed by bacterial isolation in the laboratory. The result shows that there were differences between gram-positive and gram-negative bacteria in the three research sites and that gram-positive bacteria were higher or dominant. Further research that can identify the bacteria species and explain its relationship to the ecosystem is highly recommended.Keywords: Bacteria, Scleractinian coral, gram-positive and -negative, Bunaken, Morotai, Raja Ampat  AbstrakPenelitian tentang karang keras (Scleractinian coral) yang terkontaminasi bakteri masih belum banyak dilakukan, terutama di perairan Indonesia. Penelitian ini mengambil sampel mucus karang pada tahun 2010 di 3 (tiga) lokasi berbeda, yakni Bunaken (Mei); Morotai (September) dan Raja Ampat (November), yang difokuskan pada analisis bakteri gram postif dan gram negatif. Metode yang digunakan untuk pengambilan sampel di lapangan adalah time swim, yaitu dengan penyelaman pada kedalaman 5-10 meter selama ±30 menit dan mengambil sampel mucus karang secara acak menggunakan siring atau dengan mengambil langsung pada karang (fraksi cabang). Sampel mucus dianalisis dengan cara isolasi bakteri di laboratorium. Hasil analisis menunjukkan bahwa ada perbedaan antara bakteri gram positif dan gram negative di tiga lokasi survei dan bakteri gram positif lebih tinggi atau dominan. Penelitian lebih lanjut yang dapat menentukan jenis bakteri serta menjelaskan hubungannya dengan ekosistem sangat disarankan untuk dilakukan.Kata Kunci : Bakteri, Scleractinian coral, gram positif dan negatif, Bunaken, Morotai, Raja Ampat

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