Colonization ability of Escherichia coli and Listeria monocytogenes in the endosphere of sweet pepper (Capsicum annuum var. grossum)

Abstract

Fruits and vegetables can be transmission vehicles of human opportunistic and obligate pathogenic bacteria, persisting in inner tissues for shorter or longer periods or colonizing the plants as facultative endophytes. In this study we investigated the ability of commensal E. coli and pathogenic L. monocytogenes strains to internalize sweet pepper seedlings via seed bacterization, as germinating seeds and roots are important infi ltration sites for entry of enteric bacteria. By combining cultivation dependent and independent (PCR and FISH-CLSM) techniques we could not detect stably or transiently colonized inoculated bacteria in 6-7 weeks old pepper seedlings, suggesting that there is low risk associated with internalized enteric or human pathogenic bacteria via germinating seeds in sweet pepper.

Influence of agronomic practices and pre-harvest conditions on the attachment and development of Listeria monocytogenes in vegetables

“…At harvest, both plant and soil were analysed by culture-independent analysis that confirmed the contamination of the soil but did not find L. monocytogenes on plant leaves. Similar results were reported for sweet pepper by Füstös et al (2017). The authors performed pepper seed bacterization using L. monocytogenes and E. coli, but the culturedependent and -independent techniques applied on 6-7-weekold plants did not evidence the presence of stable or transient colonies of the inoculated bacteria, concluding that human bacterial pathogens are not able to internalise germinating seeds of sweet pepper.…”

Plants as a realized niche for Listeria monocytogenes

“… a Data on the ability of Lm to colonize plants under laboratory conditions is available with the following plant species: parsley ( Petroselinum crispum ) (Bardsley et al, 2019; Kljujev et al, 2018), lettuce ( Lactuca sativa ) (Chitarra, Decastelli, et al, 2014; Honjoh et al, 2018; Jablasone et al, 2005; Kljujev et al, 2018; Shenoy et al, 2017; Standing et al, 2013), corn salad ( Vallerianella locusta ) (Chitarra, Decastelli, et al, 2014; Hofmann et al, 2014), spinach ( Spinacia oleracea ) (Hofmann et al, 2014; Jablasone et al, 2005; Kljujev et al, 2018), mustard spinach ( Brassica rapa ) (Koseki, Mizuno, Yamamoto, 2011), cultivated rocket ( Eruca sativa ) (Chitarra, Decastelli, et al, 2014; Settanni et al, 2012), wild rocket ( Diplotaxis tenuifolia ) (Chitarra, Decastelli, et al, 2014), cress ( Lepidium sativum ) (Jablasone et al, 2005), carrot ( Daucus carota ) (Kljujev et al, 2018), radish ( Raphanus raphanistrum ) (Jablasone et al, 2005), sweet pepper ( Capsicum annuum ) (Füstös et al, 2017), basil ( Ocimum basilicum ) (Bardsley et al, 2019; Chitarra, Decastelli, et al, 2014; Settanni et al, 2012), cilantro ( Coriandrum sativum ), dill ( Anethum graveolens ) (Bardsley et al, 2019), tomato ( Solanum lycopersicum ) (Honjoh et al, 2016), cantaloupe ( Cucumis melo ) (Nyarko et al, 2016), peach ( Prunus persica ), plum ( Prunus domestica ) (Collignon & Korsten, 2010), sweet corn ( Zea mays ) (Kljujev et al, 2018), alfalfa sprouts ( Medicago sativa ) (Adhikari et al, 2019), pigeon pea ( Cajanus cajan ) (Sharma et al, 2020), Arabidopsis ( Arabidopsis thaliana ) (Milillo et al, 2008), and Fescue grass ( Festuca arundinacea ) (Marinho et al, 2020; Sharma et al, 2020). The table presents major findings only when more than one paper is available for a given plant species.…”

“…Exudates Data on the ability of Lm to colonize plants under laboratory conditions is available with the following plant species: parsley (Petroselinum crispum) (Bardsley et al, 2019;Kljujev et al, 2018), lettuce (Lactuca sativa) (Chitarra, Decastelli, et al, 2014;Honjoh et al, 2018;Jablasone et al, 2005;Kljujev et al, 2018;Shenoy et al, 2017;Standing et al, 2013), corn salad (Vallerianella locusta) (Chitarra, Decastelli, et al, 2014;Hofmann et al, 2014), spinach (Spinacia oleracea) (Hofmann et al, 2014;Jablasone et al, 2005;Kljujev et al, 2018), mustard spinach (Brassica rapa) , cultivated rocket (Eruca sativa) (Chitarra, Decastelli, et al, 2014;Settanni et al, 2012), wild rocket (Diplotaxis tenuifolia) (Chitarra, Decastelli, et al, 2014), cress (Lepidium sativum) (Jablasone et al, 2005), carrot (Daucus carota) (Kljujev et al, 2018), radish (Raphanus raphanistrum) (Jablasone et al, 2005), sweet pepper (Capsicum annuum) (Füstös et al, 2017...…”