Bacteriocins active against plant pathogenic bacteria

2012 ◽  
Vol 40 (6) ◽  
pp. 1498-1502 ◽  
Author(s):  
Rhys Grinter ◽  
Joel Milner ◽  
Daniel Walker
Keyword(s):  
Recent Work ◽  
Pathogenic Bacteria ◽  
Plant Disease ◽  
Antimicrobial Agents ◽  
Genetic Resistance ◽  
Diverse Range ◽  
Phytopathogenic Bacteria ◽  
Gram Negative ◽  
Identification And Characterization

Gram-negative phytopathogens cause significant losses in a diverse range of economically important crop plants. The effectiveness of traditional countermeasures, such as the breeding and introduction of resistant cultivars, is often limited by the dearth of available sources of genetic resistance. An alternative strategy to reduce loss to specific bacterial phytopathogens is to use narrow-spectrum protein antibiotics such as colicin-like bacteriocins as biocontrol agents. A number of colicin-like bacteriocins active against phytopathogenic bacteria have been described previously as have strategies for their application to biocontrol. In the present paper, we discuss these strategies and our own recent work on the identification and characterization of candidate bacteriocins and how these potent and selective antimicrobial agents can be effectively applied to the control of economically important plant disease.

Application of commercial test-systems to identify gram-negative facultatively anaerobic bacteria

2016 ◽  
Vol 3 (1) ◽  
pp. 43-48 ◽  
Author(s):  
V. Patyka ◽  
L. Butsenko ◽  
L. Pasichnyk
Keyword(s):  
Erwinia Amylovora ◽  
Anaerobic Bacteria ◽  
Biochemical Properties ◽  
Test System ◽  
Phytopathogenic Bacteria ◽  
Gram Negative ◽  
Test Systems ◽  
Facultatively Anaerobic ◽  
Microbiological Methods

Aim. To validate the suitability of commercial API 20E test-system (bioMerieux) for the identifi cation and characterization of facultative gram-negative phytopathogenic bacterial isolates. Methods. Conventional mi- crobiological methods, API 20E test-system (bioMerieux) according to the manufacturer’s instructions. Re- sults. The identifi cation results for Erwinia amylovora, Pectobacterium carotovorum and Pantoea agglome- rans isolates were derived from the conventional and API 20E test systems, which, were in line with the literature data for these species. The API 20E test-system showed high suitability for P. agglomerans isolates identifi cation. Although not all the species of facultatively anaerobic phytopathogenic bacteria may be identi- fi ed using API 20E test-system, its application will surely allow obtaining reliable data about their physiologi- cal and biochemical properties, valuable for identifi cation of bacteria, in the course of 24 h. Conclusions. The results of tests, obtained for investigated species while using API 20E test-system, and those of conventional microbiological methods coincided. The application of API 20E test-system (bioMerieux) ensures fast obtain- ing of important data, which may be used to identify phytopathogenic bacteria of Erwinia, Pectobacterium, Pantoea genera.

scholarly journals Identification and Characterization of the Major Porin of Desulfovibrio vulgaris Hildenborough

2017 ◽  
Vol 199 (23) ◽  
Author(s):  
Lucy Zeng ◽  
Etsuko Wooton ◽  
David A. Stahl ◽  
Peter J. Walian
Keyword(s):  
Electron Microscopy ◽  
Sequence Analysis ◽  
Model Organism ◽  
Desulfovibrio Vulgaris ◽  
Gram Negative Bacteria ◽  
Diverse Range ◽  
Gram Negative ◽  
Content Type ◽  
Sulfate Reducing

ABSTRACT Due in large part to their ability to facilitate the diffusion of a diverse range of solutes across the outer membrane (OM) of Gram-negative bacteria, the porins represent one of the most prominent and important bacterial membrane protein superfamilies. Notably, for the Gram-negative bacterium Desulfovibrio vulgaris Hildenborough, a model organism for studies of sulfate-reducing bacteria, no genes for porins have been identified or proposed in its annotated genome. Results from initial biochemical studies suggested that the product of the DVU0799 gene, which is one of the most abundant proteins of the D. vulgaris Hildenborough OM and purified as a homotrimeric complex, was a strong porin candidate. To investigate this possibility, this protein was further characterized biochemically and biophysically. Structural analyses via electron microscopy of negatively stained protein identified trimeric particles with stain-filled depressions and structural modeling suggested a β-barrel structure for the monomer, motifs common among the known porins. Functional studies were performed in which crude OM preparations or purified DVU0799 was reconstituted into proteoliposomes and the proteoliposomes were examined for permeability against a series of test solutes. The results obtained establish DVU0799 to be a pore-forming protein with permeability properties similar to those observed for classical bacterial porins, such as those of Escherichia coli. Taken together, these findings identify this highly abundant OM protein to be the major porin of D. vulgaris Hildenborough. Classification of DVU0799 in this model organism expands the database of functionally characterized porins and may also extend the range over which sequence analysis strategies can be used to identify porins in other bacterial genomes. IMPORTANCE Porins are membrane proteins that form transmembrane pores for the passive transport of small molecules across the outer membranes of Gram-negative bacteria. The present study identified and characterized the major porin of the model sulfate-reducing bacterium Desulfovibrio vulgaris Hildenborough, observing its preference for anionic sugars over neutral ones. Its predicted architecture appears to be novel for a classical porin, as its core β-barrel structure is of a type typically found in solute-specific channels. Broader use of the methods employed here, such as assays for channel permeability and electron microscopy of purified samples, is expected to help expand the database of confirmed porin sequences and improve the range over which sequence analysis-based strategies can be used to identify porins in other Gram-negative bacteria. Functional characterization of these critical gatekeeping proteins from divergent Desulfovibrio species should offer an improved understanding of the physiological features that determine their habitat range and supporting activities.

scholarly journals Ciprofloxacin-Resistant Gram-Negative Bacilli in the Fecal Microflora of Children

2006 ◽  
Vol 50 (10) ◽  
pp. 3325-3329 ◽  
Author(s):  
Xuan Qin ◽  
Yasmin Razia ◽  
James R. Johnson ◽  
Jennifer R. Stapp ◽  
Daniel R. Boster ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Antimicrobial Agents ◽  
Enterobacter Aerogenes ◽  
Fecal Excretion ◽  
Achromobacter Xylosoxidans ◽  
Resistant Bacteria ◽  
Phylogenetic Groups ◽  
Gram Negative ◽  
E Coli ◽  
Public Health Challenges

ABSTRACT The extent to which antibiotic-resistant bacteria are excreted by humans who have not been exposed to antibiotics is not known. Children, who rarely receive fluoroquinolones, provide opportunities to assess the frequency of fecal excretion by fluoroquinolone-naïve hosts of fluoroquinolone-resistant gram-negative bacilli. Fresh nondiarrheal stools from children were processed by screening them on agar containing ciprofloxacin to recover ciprofloxacin-resistant gram-negative bacilli. Resistant isolates were identified, and ciprofloxacin MICs were determined. Resistant Escherichia coli isolates were also analyzed for urovirulence-associated loci. Thirteen (2.9%) of 455 stools yielded ciprofloxacin-resistant E. coli (seven children), Stenotrophomonas maltophilia (four children), and Achromobacter xylosoxidans and Enterobacter aerogenes (one child each). Neither the subjects themselves nor members of their households used fluoroquinolones in the 4 weeks preceding collection. Six of the seven resistant E. coli isolates belonged to phylogenetic groups B2 and D, in which extraintestinal pathogenic E. coli bacteria are frequently found. All resistant E. coli isolates contained at least three putative E. coli virulence loci. Most ciprofloxacin-resistant bacteria were resistant to additional antibiotics. Potentially pathogenic bacteria that are resistant to therapeutically important antimicrobial agents are excreted by some humans, despite these persons' lack of exposure to the particular drugs. The sources of these resistant organisms are unknown. This underrecognized reservoir of drug-resistant potential pathogens poses public health challenges.

scholarly journals Identification and characterization ofDaldinia eschscholtziiisolated from skin scrapings, nails, and blood

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2637 ◽  
Author(s):  
Kee Peng Ng ◽  
Chai Ling Chan ◽  
Su Mei Yew ◽  
Siok Koon Yeo ◽  
Yue Fen Toh ◽  
...  
Keyword(s):  
Internal Transcribed Spacer ◽  
Woody Plants ◽  
Antimicrobial Agents ◽  
Inhibitory Concentration ◽  
Antifungal Susceptibility ◽  
Future Studies ◽  
Identification And Characterization ◽  
Morphological And Molecular Characterization

BackgroundDaldinia eschscholtziiis a filamentous wood-inhabiting endophyte commonly found in woody plants. Here, we report the identification and characterization of nineD. eschscholtziiisolates from skin scrapings, nail clippings, and blood.MethodsThe nine isolates were identified based on colony morphology, light microscopy, and internal transcribed spacer (ITS)-based phylogeny.In vitroantifungal susceptibility of the fungal isolates was evaluated by the Etest to determine the minimum inhibitory concentration (MIC).ResultsThe nine isolates examined were confirmed asD. eschscholtzii. They exhibited typical features ofDaldiniasp. on Sabouraud Dextrose Agar, with white felty colonies and black-gray coloration on the reverse side. Septate hyphae, branching conidiophore with conidiogenous cells budding from its terminus, and nodulisporium-like conidiophores were observed under the microscope. Phylogenetic analysis revealed that the nine isolates were clustered within theD. eschscholtziispecies complex. All the isolates exhibited low MICs against azole agents (voriconazole, posaconazole, itraconazole, and ketoconazole), as well as amphotericin B, with MIC of less than 1 µg/ml.DiscussionEarly and definitive identification ofD. eschscholtziiis vital to reducing misuse of antimicrobial agents. Detailed morphological and molecular characterization as well as antifungal profiling ofD. eschscholtziiprovide the basis for future studies on its biology, pathogenicity, and medicinal potential.

Synthesis and Characterization of Novel 1,3,5-Thiadiazine Derivatives Integrated with Quinoline Moiety as Potent Antimicrobial Agents

2020 ◽  
Vol 5 (2) ◽  
pp. 149-155
Author(s):  
M. Idrees ◽  
Naqui J. Siddiqui ◽  
Yogita G. Bodkhe ◽  
Satish Kola
Keyword(s):  
13C Nmr ◽  
Mass Spectra ◽  
Antimicrobial Agents ◽  
Synthesis And Characterization ◽  
Pathogenic Microorganism ◽  
Bacterial Strains ◽  
Gram Negative ◽  
E Coli

An expeditious synthesis of series of novel 1,3,5-thiadiazine (5a-f) and (6a-f) derivatives have been described. These compounds were synthesized by reaction of 1-(N-((6-methyl-2-(p-tolyloxy)quinoline- 3-yl)methylene)carbamimidoyl)-3-arylthiourea (3a-b) derivatives with N-aryl isocyanodichloride (4a-c) in chloroform followed by basification with dilute NH4OH to give the target compounds 5a-f; which were acetylated further to afford six novel 1,3,5-thiadiazin-3-(6H)-yl)ethanone (6a-f) derivatives. Synthesis of intermediate compounds 3a-b was obtained by reacting 6-methyl-2-(p-tolyloxy)quinoline-3- carbaldehyde (2a) and 1-carbamimidoyl-3-aryllthiourea (1a-b) in chloroform. Structures of compounds 5a-f and 6a-f were established by FTIR, 1H & 13C NMR, mass spectra and further supported by elemental analysis. All synthesized compounds were investigated for their in vitro antimicrobial screening against a panel of pathogenic microorganism comprising S. aureus as Gram positive while E. coli, P. vulgaris, S. typhi as Gram-negative bacterial strains.

scholarly journals OctoPartenopin: Identification and Preliminary Characterization of a Novel Antimicrobial Peptide from the Suckers of Octopus vulgaris

Marine Drugs ◽  
2020 ◽  
Vol 18 (8) ◽  
pp. 380 ◽  
Author(s):  
Valeria Maselli ◽  
Emilia Galdiero ◽  
Anna Maria Salzano ◽  
Andrea Scaloni ◽  
Angela Maione ◽  
...  
Keyword(s):  
Animal Behavior ◽  
Maternal Care ◽  
Antimicrobial Agents ◽  
Octopus Vulgaris ◽  
Gram Negative Bacteria ◽  
Food Preservatives ◽  
Gram Negative ◽  
Health Concerns ◽  
Conventional Antibiotics

Microorganism resistance to conventional antibiotics represents one of the major global health concerns. This paper focuses on a peptide (OctoPartenopin) extracted from suckers of Octopus vulgaris; bioassay-guided chromatographic fractionation was used to identify this sequence, which holds significant antibacterial activity against Gram-positive and Gram-negative bacteria. OctoPartenopin is encrypted within the calponin sequence and was associated with the high levels of proteolytic activity already reported in octopus arm suckers. We synthesized the parent peptide and four analogues; all peptide were tested for their antibacterial and antibiofilm activities. Preliminary antibiofilm experiments showed that that one of the analogues had the best activity in both inhibition and eradication of biofilm of all three microorganisms tested. The occurrence of OctoPartenopin in arm suckers provided novel speculative information on animal behavior, as concerns maternal care of fertilized eggs. Our results highlight that suckers are a rich source of multifaceted peptides to develop alternative antimicrobial agents and food preservatives.

scholarly journals Carriage of multi-drug resistant Gram-negative pathogenic bacteria by the house fly Musca domestica

2017 ◽  
Vol 26 (1) ◽  
pp. 91-99
Author(s):  
Tangin Akter ◽  
Sangita Ahmed ◽  
Badhan Rani Das
Keyword(s):  
Body Surface ◽  
Pathogenic Bacteria ◽  
Alimentary Tract ◽  
Antimicrobial Agents ◽  
House Fly ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
House Flies ◽  
E Coli ◽  
External Body

Fifteen house flies were used to isolate bacteria from external body surface and alimentary tract. A total of 50 isolates were obtained from the house flies, of which 25 (50%) were collected from the external body surface and 25 (50%) from alimentary gut. Fifteen isolates (30%) were obtained from Shamsunnahar Hall (SN) dining room, 22 (44%) from Dhaka Medical College Hospital (DMCH) and 13 (26%) from Rokeya Hall (RH) canteen. Six Gram-negative bacteria were isolated from the house flies namely, Escherichia coli (36%), Shigella spp. (22%), Salmonella spp. (18%), Pseudomonas spp. (10%), Klebsiella spp. (8%) and Enterobacter spp. (6%). E. coli was the highest in number in all three study areas which was 33% in SN Hall dining, 36% in DMCH, and 39% in RH canteen. E. coli was present in 32 and 40% of external body surface and gut samples, respectively. Bacterial susceptibility to antimicrobial agents showed that E. coli isolates were highly resistant (66-77.7%) to ampicillin, ciprofloxacilin and penicillin antibiotics. Salmonella isolates were sensitive to chloramphenicol but it was (55.5%) resistant to ampicillin, penicillin, tetracycline, gentamycin and imipenem antibiotics. In case of Shigella and Pseudomonas, 72.72 and 80% isolates were resistant to tetracycline and chloramphenicol, respectively. Among the Enterobacter spp. 66.66% were resistant to chloramphenicol, imipenem, vancomycin and tetracycline, while Klebsiella showed 100% resistant pattern to tetracycline in the study. It was observed that house flies carry several multidrug resistant Gram-negative bacteria in their body surface and alimentary tract and played a role in the transmission of serious diseases to human. Dhaka Univ. J. Biol. Sci. 26(1): 91-99, 2017 (January)

scholarly journals Isolation, Identification and Characterization of Gram Negative Bacteria from Popular Street Food (Chotpoti) at Savar Area, Dhaka, Bangladesh

OALib ◽  
2018 ◽  
Vol 05 (11) ◽  
pp. 1-11 ◽  
Author(s):  
A. H. Happy ◽  
M. G. Alam ◽  
S. Mahmud ◽  
M. A. S. Imran ◽  
M. H. Rony ◽  
...  
Keyword(s):  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Street Food ◽  
Identification And Characterization
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