A human pathogenic bacterium Shigella proliferates in plants through adoption of type III effectors for shigellosis

Abstract

Shigella, which infects primates, can be transmitted via fresh vegetables; however, its molecular interactions with plants have not been elucidated. Here, we show that four Shigella strains, Shigella boydii, Shigella sonnei, Shigella flexneri 2a, and S. flexneri 5a, proliferate at different levels in Arabidopsis thaliana. Microscopic studies revealed that these bacteria were present inside leaves and damaged plant cells. Green fluorescent protein (GFP)‐tagged S. boydii and S. flexneri 5a colonized leaves only, whereas S. flexneri 2a colonized both leaves and roots. Using Shigella mutants lacking type III secretion systems (T3SSs), we found that T3SSs that regulate the pathogenesis of shigellosis in humans also play a central role in bacterial proliferation in Arabidopsis. Strikingly, the immunosuppressive activity of two T3S effectors, OspF and OspG, was required for proliferation of Shigella in Arabidopsis. Of note, delivery of OspF or OspG effectors inside plant cells upon Shigella inoculation was confirmed using a split GFP system. These findings demonstrate that the human pathogen Shigella can proliferate in plants by adapting immunosuppressive machinery used in the original host human.

Intranasal Immunization of Mice with Multiepitope Chimeric Vaccine Candidate Based on Conserved Autotransporters SigA, Pic and Sap, Confers Protection against Shigella flexneri

“…Protection against intracellular pathogens requires a dominant Th1-type immunity [52]. This has been demonstrated with S. Typhi, an intracellular bacterium, which after immunization using alum adjuvant and GroEL, predominantly induced Th2 types response associated with the lowest protection levels [29].…”

Plant and Human Pathogenic Bacteria Exchanging their Primary Host Environments

“…A study has demonstrated that some strains of bacteria belonging to the genus Shigella, that cause shigellosis (severe intestinal infection), can survive and multiply in damaged plant cells, roots, and leaves of A. thaliana (Jo et al 2019). These bacteria proliferate in plants by adoption of type III effectors for shigellosis.…”

Crossing the kingdom border: Human diseases caused by plant pathogens

“…P. aeruginosa utilizes common pathogenicity factors (toxA, plcS and gacA) in Arabidopsis thaliana and mouse (Rahme et al, 1995). Recently, humanpathogenic Shigella species were shown to produce type III effector proteins and interact with plant target proteins as well as being involved in human and animal pathogenesis (Jo et al, 2019).…”

“…These include some of the species in the Pantoea, Burkholderia, Rhizobium and Pseudomonas genera, all of which can cause animal disease despite being primarily known as plant disease agents. Similarly, some species of Salmonella (Schikora et al, 2008;Barak et al, 2011), Enterobacter (Nishijima et al, 2007), Shigella (Jo et al, 2019) and Enterococcus (Jha et al, 2005), mainly considered to be animal pathogens, are also capable of causing infections in plant hosts. With a few exceptions, clinical isolates of phytopathogens have largely been obtained from immunocompromised or postsurgical patients, or from post-traumatic patients (i.e.…”