title: Isolation and characterization of Enterobacteriaceae species infesting post-harvest strawberries and their biological control using bacteriophages.
abstract: Strawberry is a significantly consumed fruit worldwide, mostly without being subjected to disinfection processes. During the harvest and transfer from farm to consumers as well as where organic farming practises have been employed, the surface of the fruit may become contaminated by pathogenic bacteria. Post-harvest strawberry fruits in punnets available for public consumption were thus screened for the presence of enteric bacteria in the Sunshine Coast region of Queensland, Australia. Some of the tested samples (13 %) were found to carry such bacteria and even in greater numbers if organic amendments were used (69 %). The bacteria were found to belong in the genera of Escherichia, Enterobacter, Raoultella, Klebsiella, Pantoea, Shigella, Citrobacter and Cronobacter within the family Enterobacteriaceae. Some of the isolates were found to adhere to Caco-2 cells representing human gut epithelium as well as carrying virulence and toxin genes. Resistance mostly against sulphafurazole, cefoxitin, ampicillin and nitrofurantoin was found among 14 different antimicrobial agents tested including 100 % resistance to cefoxitin and ampicillin in the genus Pantoea. In the second phase of the study, bacteriophages were isolated against the isolates and were subsequently applied to post-harvest fruits. A significant (P ≤ 0.001) reduction in the number of enteric bacteria was observed when a high-titre polyvalent bacteriophage suspension (×10(12) PFU/mL) was applied to the fruit surface. Bacteriophages also decreased the adhesion of the Escherichia coli isolates to Caco-2 cells. Findings might indicate that biological control using bacteriophages might be of significant value for the industry targeting to reduce pathogenic loads of bacteria on the fruit.
authors.affiliation: Genecology Research Centre and Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, QLD, Maroochydore DC, 4558, Australia. ikurtbok@usc.edu.au.
authors.forename: D Ipek
authors.initials: DI
authors.lastname: Kurtböke
authors.affiliation: Genecology Research Centre and Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, QLD, Maroochydore DC, 4558, Australia.
authors.forename: A
authors.initials: A
authors.lastname: Palk
authors.affiliation: Genecology Research Centre and Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, QLD, Maroochydore DC, 4558, Australia.
authors.forename: A
authors.initials: A
authors.lastname: Marker
authors.affiliation: Genecology Research Centre and Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, QLD, Maroochydore DC, 4558, Australia.
authors.forename: C
authors.initials: C
authors.lastname: Neuman
authors.affiliation: Genecology Research Centre and Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, QLD, Maroochydore DC, 4558, Australia.
authors.forename: L
authors.initials: L
authors.lastname: Moss
authors.affiliation: Genecology Research Centre and Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, QLD, Maroochydore DC, 4558, Australia.
authors.forename: K
authors.initials: K
authors.lastname: Streeter
authors.affiliation: Genecology Research Centre and Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, QLD, Maroochydore DC, 4558, Australia.
authors.forename: M
authors.initials: M
authors.lastname: Katouli
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001422:Bacterial Adhesion; D058491:Bacterial Load; D001435:Bacteriophages / Q000254:growth & development* / Q000302:isolation & purification*; D018938:Caco-2 Cells; D024881:Drug Resistance, Bacterial; D004755:Enterobacteriaceae / Q000145:classification / Q000302:isolation & purification* / Q000502:physiology / Q000821:virology*; D004847:Epithelial Cells / Q000382:microbiology; D005516:Food Microbiology; D031985:Fragaria / Q000382:microbiology*; D006801:Humans; D010572:Pest Control, Biological / Q000379:methods*; D011793:Queensland; D037521:Virulence Factors / Q000032:analysis
chemical_list: D000900:Anti-Bacterial Agents; D037521:Virulence Factors
keywords: Bacteriophages; Biological control; Enterobacteriaceae; Escherichia coli; Organic farming; Strawberry