The potential use of bacterial endophytes recovered from tropical fruits to control foodborne pathogens

Listeria monocytogenes and Cronobacter sakazakii are both important foodborne pathogens. Bacterial endophytes, which reside in plant cells, can provide antimicrobial compounds and protect the host organism from plant pathogens. These biological compounds could be used in agriculture and the food industry. In this thesis, we investigated the culturable bacterial community from tropical fruits and their ability to reduce and/or inhibit the growth of L. monocytogenes and/or C. sakazakii. A total of 196 bacterial endophytes were recovered from tropical fruits. Among all these bacterial endophytes, 33 (16.8%) isolates showed an inhibition zone against L. monocytogenes, while 13 (6.6%) isolates showed inhibition against C. sakazakii. The inhibitory strains were identified as Bacillus spp., Enterobacter spp., Microbacterium spp., Pantoea spp. and Pseudomonas spp. Furthermore, Pantoea spp. and Enterobacter spp. were used in challenge studies with cantaloupe and liquid infant formula and demonstrated some antagonistic activity against L. monocytogenes and C. sakazakii, respectively.