The Cultivable Bacterial Microbiota Associated to the Medicinal Plant Origanum vulgare L.: From Antibiotic Resistance to Growth-Inhibitory Properties

Abstract

Origanum vulgare L. Associated Microbiota conclusion, this study regarded the characterization of O. vulgare L. chemotype and of the bacterial communities associated to this medicinal plant, also allowing the evaluation of antibiotic resistance and antagonistic interactions. This study provided the bases for further analyses on the possible involvement of endophytic bacteria in the production of antimicrobial molecules that could have an important role in clinical and therapeutic applications.

The Microbiome of the Medicinal Plants Achillea millefolium L. and Hamamelis virginiana L.

“…They were abundant members of the leaf communities of both MPs, but differences on the genus level were monitored, indicating that each plant selects for its specific bacterial community. As our and data from other studies show, bacteria can also be prominent members of the flower communities, in particular Enterobacteriaceae (Shade et al, 2013;Aleklett et al, 2014;Junker and Keller, 2015;Wei and Ashman, 2018;Castronovo et al, 2020). In fact, Enterobacteriaceae appear to be specifically associated to the style and stamen of the flower as reported for the tree M. polymorpha (Junker and Keller, 2015).…”

“…Other comparative studies have shown that the microbiome of different plants is distinct, reflecting the specific feature of the given plant and its environment ( Copeland et al, 2015 ; Lumactud and Fulthorpe, 2018 ; Massoni et al, 2020 ). The various microbial taxa include commensals, potential pathogens but also probiotic and host growth-promoting members interacting with other microbes and the host plant in various mutualistic and antagonistic and still little understood ways ( Hardoim et al, 2015 ; Berg et al, 2016 ; Brader et al, 2017 ; Castronovo et al, 2020 ).…”

“…Further, implications of the microbiome on agricultural management ( Toju et al, 2018 ; Jones et al, 2019 ; Pacifico et al, 2019 ; Lyu et al, 2020 ), crop quality and postharvest processes ( Rillig et al, 2018 ) have been addressed. Several studies investigated the microbiome of medicinal plants (MPs), e.g., Origanum vulgare ( Pontonio et al, 2018 ; Castronovo et al, 2020 ), Matricaria chamomilla, and Calendula officinalis ( Köberl et al, 2019 ) as well as Salvia miltiorrhiza ( Chen et al, 2018 ; Huang et al, 2018 ). MPs are characterized by a high variety of unique secondary metabolites and many endophytes producing pharmacologically active substances ( Köberl et al, 2013 ; Golinska et al, 2015 ; Ivanova et al, 2016 ; Rahman et al, 2017 ; Caruso et al, 2020 ; Gupta et al, 2020 ; Teimoori-Boghsani et al, 2020 ).…”

Medicinal Plants and Their Bacterial Microbiota: A Review on Antimicrobial Compounds Production for Plant and Human Health

“…Lastly, but not least, endophytes could be selected in relation to their antimicrobial resistance phenotype as a response to antimicrobial molecules produced by microorganisms in the same ecological niche [ 31 ]. This hypothesis has been suggested in the case of the three MPs, E. purpurea and E. angustifolia [ 13 , 31 , 36 ], and O. vulgare [ 37 ]. Here, different plant compartments were characterized by different antimicrobial resistance patterns and antagonistic interactions.…”

“…Human health is seriously threatened by the constant emergence of multi-drug resistant (MDR) microorganisms and the drying up of the pipelines of new antibiotic discovery. Many studies have demonstrated that bacterial endophytes of MPs could be promising sources of antimicrobial molecules [ 37 , 38 , 39 , 68 , 99 , 100 ]. On the other hand, since 1985, very few new classes of antibiotics have been discovered, highlighting the need for an alternative strategy to isolate effective antibiotics from endophytes [ 69 ].…”