scholarly journals Chemically modified chitosans as antimicrobial agents against some plant pathogenic bacteria and fungi

2010 ◽  
Vol 46 (No. 4) ◽  
pp. 149-158 ◽  
Author(s):  
E.I. Rabea ◽  
W. Steurbaut
Keyword(s):  
High Activity ◽  
Spore Germination ◽  
Mycelial Growth ◽  
Pathogenic Bacteria ◽  
Antimicrobial Agents ◽  
Erwinia Carotovora ◽  
Fungal Spore ◽  
Plant Pathogenic Bacteria ◽  
Chemically Modified

The antimicrobial activity of eight chemically modified chitosans against plant pathogenic bacteria of crown gall disease Agrobacterium tumefaciens and soft mould disease Erwinia carotovora and fungi of early blight disease Alternaria alternata, root rot disease Fusarium oxysporum, and damping off disease Pythium debaryanum was investigated. The minimum inhibitory concentration (MIC) of these compounds against the tested bacteria showed that N-(o,o-dichlorobenzyl)chitosan exhibited a high activity against A. tumefaciens and E. carotovora (MIC = 500 and 480 mg/l, respectively). In addition, the antifungal behaviour was investigated in vitro on mycelial growth and spore germination. N-(p-fluorobenzyl)chitosan was the most active against the mycelial growth of A. alternata with an EC<sub>50</sub> of 703.4 mg/l, while the N-(o-chloro,o-fluorobenzyl)chitosan exhibited a high activity against F. oxysporum and P. debaryanum (EC<sub>50</sub> = 641.2 and 155.7 mg/l, respectively). Against the fungal spore germination, all modified chitosans showed a higher inhibition of spore germination than unmodified chitosan. The compound of N-(o,o-di fluorobenzyl)chitosan exhibited a high inhibition percentage against A. alternata. However, N-(o-chlorobenzyl)chitosan and N-(p-chlorobenzyl)chitosan were significantly highly active against the spore germination of F. oxysporum.

scholarly journals The Antibacterial Activity of Chitosan Products Blended with Monoterpenes and Their Biofilms against Plant Pathogenic Bacteria

Scientifica ◽  
2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Mohamed E. I. Badawy ◽  
Entsar I. Rabea ◽  
Nehad E. M. Taktak ◽  
Mahmoud A. M. El-Nouby
Keyword(s):  
Antibacterial Activity ◽  
Pathogenic Bacteria ◽  
Biological Activities ◽  
Average Molecular Weight ◽  
Erwinia Carotovora ◽  
Food Protection ◽  
Plant Pathogenic Bacteria ◽  
Agar Dilution ◽  
Microbial Attack

This study focuses on the biological activities of eleven chitosan products with a viscosity-average molecular weight ranging from 22 to 846 kDa in combination with the most active monoterpenes (geraniol and thymol), out of 10 tested, against four plant pathogenic bacteria,Agrobacterium tumefaciens,Erwinia carotovora,Corynebacterium fascians, andPseudomonas solanacearum. The antibacterial activity was evaluatedin vitroby the agar dilution technique as a minimum inhibitory concentration (MIC) that was found to be dependent on the type of the microorganism tested. The most active product of chitosan was used for biofilm production enriched with geraniol and thymol (0.1 and 0.5%) and the films were also evaluated against the tested bacteria. The biological bioactivities summarized here may provide novel insights into the functions of chitosan and some monoterpenes and potentially allow their use for food protection from microbial attack.

Chemotaxis of some phytopathogenic bacteria to fungal propagules in vitro and in soil

1988 ◽  
Vol 34 (2) ◽  
pp. 196-199 ◽  
Author(s):  
W. C. Lim ◽  
J. L. Lockwood
Keyword(s):  
Pseudomonas Syringae ◽  
Xanthomonas Campestris ◽  
Pathogenic Bacteria ◽  
Erwinia Carotovora ◽  
Bipolaris Sorokiniana ◽  
Macrophomina Phaseolina ◽  
Plant Pathogenic Bacteria ◽  
Fungal Propagules ◽  
Xanthomonas Campestris Pv Campestris

The motile plant pathogenic bacteria Erwinia carotovora pv. carotovora, Pseudomonas syringae pv. phaseolicola, and Xanthomonas campestris pv. campestris were strongly attracted to conidia of Bipolaris sorokiniana, B. victoriae, and to sclerotia of Macrophomina phaseolina and their exudates in vitro and in soil, but not to phosphate buffer or buffer–soil mixtures. Bacteria accumulated radioactivity within 1 h after being placed in exudates from 14C-labelled conidia of B. sorokiniana. After 5 h, radioactivity of the 14C-labelled exudate was reduced to 29–54% of that in the original medium. Exudates from fungal propagules may act as attractants and substrates for motile plant pathogenic bacteria in soil.

Preliminary in Vitro Investigations on The Inhibitory Activity of The Original Dietary Supplement Oxidal® on Pathogenic Bacterial Strains

2020 ◽  
Vol 11 ◽  
pp. 37-43
Author(s):  
Prof. Teodora P. Popova ◽  
Toshka Petrova ◽  
Ignat Ignatov ◽  
Stoil Karadzhov
Keyword(s):  
Dietary Supplement ◽  
Broad Spectrum ◽  
Pathogenic Bacteria ◽  
Antimicrobial Agents ◽  
Clinical Effectiveness ◽  
Inhibitory Effect ◽  
Diffusion Method ◽  
Bacterial Strains ◽  
Microbial Strains

The antimicrobial action of the dietary supplement Oxidal® was tested using the classic Bauer and Kirby agar-gel diffusion method. Clinical and reference strains of Staphylococcus aureus and Escherichia coli were used in the studies. The tested dietary supplement showed a well-pronounced inhibitory effect against the microbial strains commensurable with that of the broad-spectrum chemotherapeutic agent Enrofloxacin and showed even higher activity than the broad spectrum antibiotic Thiamphenicol. The proven inhibitory effect of the tested dietary supplement against the examined pathogenic bacteria is in accordance with the established clinical effectiveness standards for antimicrobial agents.

THE ACTIVITY OF ESSENTIAL OILS OBTAINED FROM SPECIES AND INTERSPECIES HYBRIDS OF THE Mentha GENUS AGAINST SELECTED PLANT PATHOGENIC BACTERIA

2018 ◽  
Vol 17 (6) ◽  
pp. 167-174 ◽  
Author(s):  
Małgorzata Schollenberger ◽  
Tomasz M. Staniek ◽  
Elżbieta Paduch-Cichal ◽  
Beata Dasiewicz ◽  
Agnieszka Gadomska-Gajadhur ◽  
...  
Keyword(s):  
Essential Oils ◽  
Pseudomonas Syringae ◽  
Pathogenic Bacteria ◽  
Antimicrobial Effect ◽  
Mentha Piperita ◽  
Mentha Spicata ◽  
Plant Essential Oils ◽  
Plant Pathogenic Bacteria ◽  
Interspecies Hybrids

Plant essential oils of six aromatic herb species and interspecies hybrids of the family Lamiaceae – chocolate mint (Mentha piperita × ‘Chocolate’), pineapple mint (Mentha suaveolens ‘Variegata’), apple mint (Mentha × rotundifolia), spearmint (Mentha spicata), orange mint (Mentha × piperita ‘Granada’) and strawberry mint (Mentha × villosa ‘Strawberry’) – were investigated for antimicrobial effects against plant pathogenic bacteria: Agrobacterium tumefaciens, Pseudomonas syringae pv. syringae and Xanthomonas arboricola pv. corylina. The screening was carried out in vitro on agar plates filled with the target organism. All essential oils screened exhibited a higher level of antibacterial activity against A. tumefaciens and X. arboricola pv. corylina than streptomycin used as a standard in all tests. The antimicrobial effect of streptomycin and five mint oils was at the same level for P. syringae pv. syringae. There were no significant differences in the influence of the chocolate mint oil on the growth inhibition of all bacteria tested. Plant essential oils from pineapple mint, apple mint, spearmint and strawberry mint showed the weakest antimicrobial activity against P. syringae pv. syringae and the strongest towards A. tumefaciens and X. arboricola pv. corylina. The essential oils from strawberry mint, pineapple mint, spearmint and apple mint had the strongest effect on A. tumefaciens, and the lowest inhibitory activity was exhibited by the chocolate mint and orange mint essential oils. X. arboricola pv. corylina was the most sensitive to the strawberry mint, pineapple mint and spearmint oils. The chocolate mint oil showed the greatest activity against P. syringae pv. syringae.

scholarly journals In vivo and in vitro antibacterial activity of neomycin against plant pathogenic bacteria

2011 ◽  
Vol 6 (34) ◽  
pp. 6829-6834, ◽  
Author(s):  
Tao Ke ◽  
Fan Jieyu ◽  
Shi Guanying ◽  
Zhang Xingang ◽  
Zhao Haoyu ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Pathogenic Bacteria ◽  
Plant Pathogenic Bacteria ◽  
In Vitro Antibacterial Activity

Screening of Existing and New Boxwood Cultivars for Disease Resistance and In Vitro Fungicide Screening to Manage Boxwood Dieback Caused by Colletotrichum theobromicola

2021 ◽  
Author(s):  
Harleen Kaur ◽  
Monique DeSouza ◽  
Raghuwinder "Raj" Singh
Keyword(s):  
Active Ingredient ◽  
Spore Germination ◽  
Mycelial Growth ◽  
Management Practices ◽  
Management Strategies ◽  
Host Susceptibility ◽  
Germination Inhibition ◽  
Industry Professionals ◽  
The U.S

Boxwood is one of the most common and widely planted perennial ornamentals in both home gardens and commercial landscapes. Recently reported boxwood dieback, a fungal disease caused by Colletotrichum theobromicola, has been spreading at an alarming rate within the U.S. Boxwood breeders, nursery growers, and landscape professionals have shown great concerns regarding the lack of effective management practices. Therefore, the primary objectives of this study were to devise effective disease management strategies including screening cultivars to determine their susceptibility to boxwood dieback and screening various fungicides to determine their effectiveness in managing the disease. Host range studies were conducted by screening a wide variety of boxwood cultivars under greenhouse conditions. Although, boxwood cultivar ‘Little Missy’ showed much delayed symptom expression as compared to rest of the cultivars but none of the 11 cultivars were found to be resistance to boxwood dieback. In vitro screening of nine fungicides was conducted to determine mycelial growth as well as spore germination inhibition of eight isolates of C. theobromicola collected from eight states in the U.S. Of the nine fungicides, difenoconazole+pydiflumetofen showed maximum mycelial growth and spore germination inhibition at 1 ppm active ingredient followed by fluxapyroxad+pyraclostrobin, and pyraclostrobin+boscalid at 5 ppm active ingredient. Azoxystrobin+benzovindiflupyr significantly inhibited mycelial growth at 1 ppm but reduced spore germination at 10 ppm active ingredient. This study provides the boxwood industry professionals with critical and applied information pertaining to host susceptibility and fungicide efficacy to effectively mitigate boxwood dieback and to reduce its further spread.

scholarly journals Evaluation and Comparison of Antibacterial Efficacy of Herbal Extracts in Combination with Antibiotics on Periodontal pathobionts: An in vitro Microbiological Study

Antibiotics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 89 ◽  
Author(s):  
Shahabe Abullais Saquib ◽  
Nabeeh Abdullah AlQahtani ◽  
Irfan Ahmad ◽  
Mohammed Abdul Kader ◽  
Sami Saeed Al Shahrani ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Plant Extracts ◽  
Pathogenic Bacteria ◽  
Bacterial Resistance ◽  
Antimicrobial Agents ◽  
Synergistic Activity ◽  
Antibacterial Efficacy ◽  
Herbal Extracts ◽  
Inhibition Zones

Background: In the past few decades focus of research has been toward herbal medicines because of growing bacterial resistance and side effects of antimicrobial agents. The extract derived from the plants may increase the efficacy of antibiotics when used in combination against pathogenic bacteria. In the current study, the synergistic antibacterial efficacy of plant extracts in combination with antibiotics has been assessed on selected periodontal pathogens. Methods: Ethanolic extracts were prepared from Salvadora persica (Miswak) and Cinnamomum zeylanicum (Ceylon cinnamon), by the soxhalate method. Plaque samples were collected from clinical periodontitis patients to isolate and grow the periodontal pathobionts under favorable conditions. Susceptibility of bacteria to the extracts was assessed by gauging the diameter of the inhibition zones. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of plant extracts were determined against each bacterium. Synergistic activity of plants extract in combination with antibiotics against the bacteria was also assessed by measuring the diameter of the inhibition zones. Results: Ethanolic extract of both the plants showed an inhibitory effect on the proliferation and growth of all four strains of periodontal pathobionts. Maximum antibacterial activity was exhibited by C. zeylanicum against Tannerella forsythia (MIC = 1.56 ± 0.24 mg/mL, MBC = 6.25 ± 0.68 mg/mL), whereas among all the studied groups the minimum activity was reported by C. zeylanicum against Aggregatibacter actinomycetemcomitans the (MIC = 12.5 ± 3.25 mg/mL, MBC = 75 ± 8.23 mg/mL). Combination of herbal extracts with different antibiotics revealed a synergistic antibacterial effect. The best synergism was exhibited by S. persica with metronidazole against A. actinomycetemcomitans (27 ± 1.78). Conclusions: Current in vitro study showed variable antibacterial activity by experimented herbal extracts against periodontal pathobionts. The synergistic test showed significant antibacterial activity when plant extracts were combined with antibiotics.

scholarly journals Chloramphenicol Resurrected: A Journey from Antibiotic Resistance in Eye Infections to Biofilm and Ocular Microbiota

2019 ◽  
Vol 7 (9) ◽  
pp. 278 ◽  
Author(s):  
Lorenzo
Keyword(s):  
Pathogenic Bacteria ◽  
Bacterial Resistance ◽  
Antimicrobial Agents ◽  
In Vivo Studies ◽  
Antibiofilm Activity ◽  
Eye Infections ◽  
Treatment And Prevention ◽  
Old Drugs

The advent of multidrug resistance among pathogenic bacteria is devastating the worth of antibiotics and changing the way of their administration, as well as the approach to use new or old drugs. The crisis of antimicrobial resistance is also due to the unavailability of newer drugs, attributable to exigent regulatory requirements and reduced financial inducements. The emerging resistance to antibiotics worldwide has led to renewed interest in old drugs that have fallen into disuse because of toxic side effects. Thus, comprehensive efforts are needed to minimize the pace of resistance by studying emergent microorganisms and optimize the use of old antimicrobial agents able to maintain their profile of susceptibility. Chloramphenicol is experiencing its renaissance because it is widely used in the treatment and prevention of superficial eye infections due to its broad spectrum of activity and other useful antimicrobial peculiarities, such as the antibiofilm properties. Concerns have been raised in the past for the risk of aplastic anemia when chloramphenicol is given intravenously. Chloramphenicol seems suitable to be used as topical eye formulation for the limited rate of resistance compared to fluoroquinolones, for its scarce induction of bacterial resistance and antibiofilm activity, and for the hypothetical low impact on ocular microbiota disturbance. Further in-vitro and in vivo studies on pharmacodynamics properties of ocular formulation of chloramphenicol, as well as its real impact against biofilm and the ocular microbiota, need to be better addressed in the near future.

In vitro assessment of N-(benzyl)chitosan derivatives against some plant pathogenic bacteria and fungi

2009 ◽  
Vol 45 (1) ◽  
pp. 237-245 ◽  
Author(s):  
Entsar I. Rabea ◽  
Mohamed E.I. Badawy ◽  
Walter Steurbaut ◽  
Christian V. Stevens
Keyword(s):  
Pathogenic Bacteria ◽  
Chitosan Derivatives ◽  
Plant Pathogenic Bacteria ◽  
In Vitro Assessment ◽  
Bacteria And Fungi
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