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
2018 ◽  
Vol 17 (6) ◽  
pp. 167-174 ◽  
Author(s):  
Małgorzata Schollenberger ◽  
Tomasz M. Staniek ◽  
Elżbieta Paduch-Cichal ◽  
Beata Dasiewicz ◽  
Agnieszka Gadomska-Gajadhur ◽  
...  

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.


2011 ◽  
Vol 6 (34) ◽  
pp. 6829-6834, ◽  
Author(s):  
Tao Ke ◽  
Fan Jieyu ◽  
Shi Guanying ◽  
Zhang Xingang ◽  
Zhao Haoyu ◽  
...  

Author(s):  
Shanjun Gao ◽  
Guangzhi Liu ◽  
Jianguo Li ◽  
Jing Chen ◽  
Lina Li ◽  
...  

Compared to mono-species biofilm, biofilms formed by cross-kingdom pathogens are more refractory to conventional antibiotics, thus complicating clinical treatment and causing significant morbidity. Lemongrass essential oil and its bioactive component citral were previously demonstrated to possess strong antimicrobial efficacy against pathogenic bacteria and fungi. However, their effects on polymicrobial biofilms remain to be determined. In this study, the efficacy of lemongrass (Cymbopogon flexuosus) essential oil and its bioactive part citral against dual-species biofilms formed by Staphylococcus aureus and Candida species was evaluated in vitro. Biofilm staining and viability test showed both lemongrass essential oil and citral were able to reduce biofilm biomass and cell viability of each species in the biofilm. Microscopic examinations showed these agents interfered with adhesive characteristics of each species and disrupted biofilm matrix through counteracting nucleic acids, proteins and carbohydrates in the biofilm. Moreover, transcriptional analyses indicated citral downregulated hyphal adhesins and virulent factors of Candida albicans, while also reducing expression of genes involved in quorum sensing, peptidoglycan and fatty acids biosynthesis of S. aureus. Taken together, our results demonstrate the potential of lemongrass essential oil and citral as promising agents against polymicrobial biofilms as well as the underlying mechanisms of their activity in this setting.


2017 ◽  
Vol 10 (1) ◽  
pp. 1-5
Author(s):  
Renato Clini Cervi ◽  
Maria Auxiliadora Andrade ◽  
Cíntia Silva Minafra-Rezende ◽  
Marcos Barcellos Café

Eggs have protective structures against possible contamination by bacteria and fungi. Pathogenic bacteria such as Salmonella spp. are therefore rarely found in adequate sanitary conditions. Few studies about the contamination of ratite eggs have been reported, and although some studies have focused on ostrich eggs, there is no information about Greater Rhea ( Rhea americana) eggs. The microorganisms that contaminate ratite eggs do not differ from those that affect other bird species. The purpose of this study was to characterise contamination in 16 eggs, supplied by a commercial breeding facility, by Enterobacteriaceae contamination and to assess the in vitro resistance to experimental contamination by Salmonella Enteritidis using analytical tests following the guidelines of the Georgia Poultry Laboratory. These elements are critical to the storage period, quality and physicochemical parameters. The results revealed the presence of the genera Proteus, Klebsiella, Citrobacter and Enterobacter related to the location of nests. Greater Rhea eggs were also found to be highly resistant to experimental infection by Salmonella Enteritidis.


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