Systemic colonization of clover (Trifolium repens) by Clostridium botulinum strain 2301

Abstract

In recent years, cases of botulism in cattle and other farm animals and also in farmers increased dramatically. It was proposed, that these cases could be affiliated with the spreading of compost or other organic manures contaminated with Clostridium botulinum spores on farm land. Thus, soils and fodder plants and finally farm animals could be contaminated. Therefore, the colonization behavior and interaction of the botulinum neurotoxin (BoNT D) producing C. botulinum strain 2301 and the non-toxin producing Clostridium sporogenes strain 1739 were investigated on clover (Trifolium repens) in a field experiment as well as in phytochamber experiments applying axenic and additionally soil based systems under controlled conditions. Plants were harvested and divided into root and shoot parts for further DNA isolation and polymerase chain reaction (PCR) assays; subsamples were fixed for fluorescence in situ hybridization analysis in combination with confocal laser scanning microscopy. In addition, we observed significant differences in the growth behavior of clover plants when inoculated with clostridial spores, indicating a plant growth promoting effect. Inoculated plants showed an increased growth index (shoot size, wet and dry weight) and an enlarged root system induced by the systemic colonization of clover by C. botulinum strain 2301. To target C. botulinum and C. sporogenes, 16S rDNA directed primers were used and to specifically detect C. botulinum, BoNT D toxin genes targeted primers, using a multiplex PCR approach, were applied. Our results demonstrate an effective colonization of roots and shoots of clover by C. botulinum strain 2301 and C. sporogenes strain 1739. Detailed analysis of colonization behavior showed that C. botulinum can occur as individual cells, in cell clusters and in microcolonies within the rhizosphere, lateral roots and within the roots tissue of clover.

Clostridium bifermentans and C. subterminale are associated with kiwifruit vine decline, known as moria, in Italy

“…, 2004; Zeiller et al . , 2015), and that they can systemically migrate from the roots to the vascular xylem, behaving as true endophytes (Zeiller et al . , 2015).…”

“…, 2015), and that they can systemically migrate from the roots to the vascular xylem, behaving as true endophytes (Zeiller et al . , 2015). Herein, we have observed that A. chinensis and A. arguta apparently react differently to the artificial inoculations by showing different patterns of disease progression, suggesting that, similar to aerobic plant‐pathogenic bacteria, Clostridium spp.…”

Metagenomic analysis of medicinal Cannabis samples; pathogenic bacteria, toxigenic fungi, and beneficial microbes grow in culture-based yeast and mold tests

“…Previous white papers have suggested C. botulinum is not a threat in Cannabis due to its anaerobic nature ( http://cannabissafetyinstitute.org/wp-content/uploads/2015/06/Microbiological-Safety-Testing-of-Cannabis.pdf). However, C. botulinum should not be considered an irrelevant threat in Cannabis because it is known to vascularize as an endophyte in plants and produce pasteurization resistant spores 39 . Additionally, proximity between cultivation and processing may lead to contamination of finished products such as emulsified oils or concentrated extracts containing water.…”

Phyllospheric Microbiomes: Diversity, Ecological Significance, and Biotechnological Applications

“…Endophytic Bacillus produces phytohormones such as abscisic acid, auxins, brassinosteroids, cytokinins, ethylene, gibberellins, jasmonates, and strigolactones, and increases nutrient (nitrogen and phosphorous) accessibility to the host (Reinhold-Hurek and Hurek 2011;Brader et al 2014;Santoyo et al 2016;Shahzad et al 2016;Ek-Ramos et al 2019). Zeiller et al (2015) reported that C. botulinum 2301 significantly produce PGPs in a field experiment of clover. A cold-tolerant bacterial strain Exiguobacterium acetylicum 1P promotes wheat seedlings growth (Selvakumar et al 2010), Brevibacillus brevis improve the growth of cotton crop (Nehra et al 2016) and Bacillus spp.…”