Antibacterial activity of plant methanolic extracts on a field isolate of <i>Pseudomonas syringae</i> pvtomato from the Casablanca region (Morocco)

Abstract

A bacterial field isolate recovered from infected tomato plants in a green-house at Sidi Rehal, a region near Casablanca city (Morocco), was identified as the gammaproteobacterium Pseudomonas syringae pv. tomato DC3000 strain, the causal agent of bacterial speck. The bacterial isolate was characterized by morphological, biochemical and molecular biological tests, its growth curves carried out in various culture media, and its phytopathogenicity verified by infection tests. A screening was performed to evaluate the antibacterial activity of methanolic extracts of 12 selected Moroccan plants against the P. syringae pv. tomato DC3000 isolate, and Agar-well diffusion and Broth microdilution methods were used to determine minimum inhibitory and minimum bactericidal concentrations. Among the methanolic extracts tested, only those of Nigella sativa, Geranuim robertianum, Aizoon canariense and Rubia peregrine showed clear inhibitory and bactericidal activities, although the highest values were achieved with N. sativa, a plant used in Morocco as a spice, condiment and medicinal treatment.

Polyphenols content and antimicrobial potential of extracts from leaves of Celtis australis

“…These results are in agreement with our previous study which has reported the antibacterial effect of hydro-methanolic extracts of leaves and seeds of C. australis 14 , as far as various extracts from this plant against S. aureus, P. aeruginosa, E. coli and B. subtilis 16 , S. aureus and P. aeruginosa 8 , P. syringe 17 and S. aureus, L. monocytogenes, P. aeruginosa and E. coli 18 . Antifungal potential: As shown in Table 5, a significant and dose-dependent antifungal effect was obtained with all extracts tested.…”

Media pH and media type can significantly affect the reliability of in vitro copper tolerance assessments of Pseudomonas syringae pv. tomato

“…; Elkhalfi et al . ), followed by the detection of the h ypersensitivity r esponse and p athogenicity‐associated Z gene ( hrpZ ; Zaccardelli et al . ) and citrate synthase ( gltA ) (Hwang et al .…”

“…tomato infection were collected from three tomato-producing regions in south-east Queensland, Australia. Species identification followed standard biochemical methods for the determination of P. syringae (Lelliott et al 1966;Elkhalfi et al 2013), followed by the detection of the hypersensitivity response and pathogenicity-associated Z gene (hrpZ; Zaccardelli et al 2005) and citrate synthase (gltA) (Hwang et al 2005;Berge et al 2014) using gene-specific PCR amplification and subsequent DNA sequencing. Reaction conditions for the PCRs varied slightly to those originally published (Table S1).…”

Taraxacum Genus: Potential Antibacterial and Antifungal Activity

“…An ethanolic extract was slightly active against B. subtilis and S. haemolyticus, but was inactive against other Gram positive and Gram negative strains, resulting in no further studies with this extract [20]. Furthermore, only weak activity was achieved by methanolic extracts of this plant against P. syringae [74].…”