Interaction between Salmonella and Plants: Potential Hosts and Vectors for Human Infection

Abstract

Fruits and vegetables are important for a healthy diet. However, when eaten raw and contaminated with human pathogens (HPs) they may cause a disease outbreak. Contamination with HPs can occur along the entire farm-to-fork production chain and Salmonella enterica is one of the most common foodborne pathogens. A range of biotic and abiotic environmental factors can inluence the complex interactions between Salmonella and plants. Moreover, the outcome of experiments largely depends on the experimental design and parameters or methods employed, and on top, on the accompanying plant microbiome and the genetic equipment of the plant and the Salmonella strain. Particularly mobile genetic elements contribute to the diversiication and adaptation of Salmonella to the plant environment. So far, litle is known about the key processes and factors inluencing the atachment and potential internalization of Salmonella in plants and the plant speciic responses. It is therefore important to beter understand the ecology of Salmonella in the soil and plant environment, in order to propose practicable recommendations for prevention of foodborne diseases. This also requires improved sensitivity and speciicity of detection methods. In this chapter, we present the current knowledge, research needs, and methodology regarding the complex interactions between Salmonella and plants.

Attachment of Salmonella enterica on Mangoes and Survival Under Conditions Simulating Commercial Mango Packing House and Importer Facility

“…Following the initial adhesion, non-reversible attachment of Salmonella on the fructoplane ensures its survival and transmission along the post-harvest continuum. As opposed to adhesion, bacterial attachment on plant surfaces is mediated by the formation of attachment structures that help to securely anchor the pathogen in place ( Collignon and Korsten, 2010 ; Tan et al, 2016 ; Fornefeld et al, 2017 ). Toward this, results of our study demonstrate that Salmonella is adept at adhering and attaching to the fructoplane.…”

“…For the successful transmission of a pathogen through fresh produce, the initial process of adhesion and attachment on the plant surface is highly critical ( Tan et al, 2016 ; Fornefeld et al, 2017 ). Adhesion refers to the reversible adsorption of bacteria to the substrate surface, which is the phylloplane or fructoplane in case of produce ( Garrett et al, 2008 ).…”

Attachment and Survival of Escherichia coli O157:H7 on In-Shell Hazelnuts

“…Following inadvertent contamination, pathogens must be able to attach, survive, and persist on the nuts in order to result in a foodborne infection. Successful adhesion and attachment of the pathogen on the epiphytic surface is critical to its survival and persistence [ 22 , 23 ]. The initial adhesion of the bacteria on coming into contact with the plant surface is characterized by weak and reversible binding to the substrate [ 24 ].…”

“…Following this, a strong irreversible binding (attachment) occurs. Once attached, removal of the pathogen cannot be readily achieved [ 23 , 25 ]. Studies on the attachment of E. coli O157:H7 indicate that this enteric pathogen can rapidly adhere and attach to different produce, including peaches, plums, alfalfa sprouts, spinach leaves, lettuce leaves, and cut green pepper [ 26 , 27 , 28 , 29 , 30 ].…”

“…Additional investigations revealed that this attachment is mediated by the production of pili, fimbriae, and non-fimbrial adhesins [ 32 ]. Once firmly attached, pathogens could potentially survive and persist on the epiphytic surface [ 23 ].…”