title: Swarm motility of Salmonella enterica serovar Typhimurium is inhibited by compounds from fruit peel extracts.
abstract: Controlling spread of human pathogens on fresh produce is a top priority for public health reasons. Isolation of compounds from agricultural waste that would control spread of human pathogens was explored using Salmonella enterica serovar Typhimurium as a model organism. In the environment, micro-organisms migrate as a 'community' especially when they move on moist surfaces. This type of motility is characterized as swarming motility. We examined extracts from agricultural waste such as soya bean husk, peels of orange, pineapple, avocado and pomegranate for antiswarming activity. Avocado and pineapple peels showed moderate (~40%) inhibition of swarming motility while pomegranate peel extract had high antiswarming activity (~85% inhibition) and was examined in further detail. Although the pomegranate peel extract was acidic, swarm-inhibitory activity was not due to low pH and the peel extract did not inhibit growth of Salmonella. Among the key swarm motility regulatory genes, class II (fliF, fliA, fliT and fliZ) and class III (fliC and fliM) regulators were downregulated upon exposure to pomegranate peel extract. Pomegranate peels offer great potential as a bioactive repellent for pathogenic micro-organisms on moist surfaces.
  
  
  CONCLUSIONS
  Controlling the spread of food-borne pathogens in moist environments is an important microbial food safety issue. Isolation of compounds from agricultural waste (such as fruit peels) that would control spread of human pathogens was explored using Salmonella enterica serovar Typhimurium as a model organism. Pomegranate peels offer great potential as a bioactive repellent for pathogenic micro-organisms.
authors.affiliation: Environmental Microbial & Food Safety Laboratory, Henry A. Wallace Beltsville Agricultural Research Center, Agricultural Research Service, USDA, Beltsville, MD, USA.
authors.forename: G
authors.initials: G
authors.lastname: Mahadwar
authors.forename: K R
authors.initials: KR
authors.lastname: Chauhan
authors.forename: G V
authors.initials: GV
authors.lastname: Bhagavathy
authors.forename: C
authors.initials: C
authors.lastname: Murphy
authors.forename: A D
authors.initials: AD
authors.lastname: Smith
authors.forename: A A
authors.initials: AA
authors.lastname: Bhagwat
mesh_terms: D031230:Ananas / Q000737:chemistry / Q000382:microbiology; D000900:Anti-Bacterial Agents / Q000737:chemistry*; D032084:Citrus sinensis / Q000737:chemistry / Q000382:microbiology; D005407:Flagella / Q000235:genetics / Q000378:metabolism; D006801:Humans; D029561:Lythraceae / Q000737:chemistry* / Q000382:microbiology*; D008826:Microbial Sensitivity Tests; D027421:Persea / Q000737:chemistry / Q000382:microbiology; D010936:Plant Extracts / Q000737:chemistry*; D012486:Salmonella typhimurium / Q000235:genetics / Q000378:metabolism*; D013025:Glycine max / Q000737:chemistry / Q000382:microbiology; D014866:Waste Products / Q000032:analysis
chemical_list: D000900:Anti-Bacterial Agents; D010936:Plant Extracts; D014866:Waste Products
keywords: agricutural waste; bacterial motility; flagella synthesis; food safety; food-borne pathogens