title: Salmonella Sofia differs from other poultry-associated Salmonella serovars with respect to cell surface hydrophobicity.
abstract: Salmonella enterica is one of the most important foodborne pathogens. Salmonella enterica subsp. II 4,12:b:- (Salmonella Sofia) is commonly found in Australian poultry. It has been suggested that physicochemical properties such as surface charge and hydrophobicity may affect bacterial attachment to surfaces and their ability to persist in food systems. A possible link between hydrophobicity cell surface charge and persistence of Salmonella from the poultry system was examined. Hydrophobicity of Salmonella Sofia (n = 14), Salmonella Typhimurium (n = 6), Salmonella Infantis (n = 3), and Salmonella Virchow (n = 2) was assayed using hydrophobic interaction chromatography, bacterial adherence to hydrocarbons (BATH), using xylene or hexadecane, and the contact angle method (CAM). Cellular surface charge (CSC) of the isolates was determined using zeta potential measurements. The majority (12 of 14) of Salmonella Sofia isolates were found to be hydrophobic when assayed using BATH with xylene, except isolates S1635 and S1636, and the other serovars were found to be hydrophilic. Salmonella Sofia isolates were not significantly different (P > 0.05) from isolates of other serovars as measured by hydrophobic interaction, BATH with hexadecane, or the CAM. No significant differences (P > 0.05) in zeta potential measurements were observed between isolates. Principal component analysis using results from all four measures of hydrophobicity allowed clear differentiation between isolates of the serovar Salmonella Sofia (except S1635 and S1636) and those of other Salmonella serovars. Differences in physicochemical properties may be a contributing factor to the Salmonella Sofia serovar's ability to attach to surfaces and persist in a food system.
authors.affiliation: Food Science Australia, Brisbane, P.O. Box 3312, Tingalpa DC, Queensland 4173, Australia.
authors.forename: T W R
authors.initials: TW
authors.lastname: Chia
authors.forename: N
authors.initials: N
authors.lastname: Fegan
authors.forename: T A
authors.initials: TA
authors.lastname: McMeekin
authors.forename: G A
authors.initials: GA
authors.lastname: Dykes
mesh_terms: D001422:Bacterial Adhesion / Q000502:physiology*; D015169:Colony Count, Microbial; D005506:Food Contamination / Q000032:analysis; D005516:Food Microbiology; D057927:Hydrophobic and Hydrophilic Interactions; D011202:Poultry Products / Q000382:microbiology*; D025341:Principal Component Analysis; D012475:Salmonella / Q000254:growth & development / Q000502:physiology*; D019779:Salmonella enterica / Q000254:growth & development / Q000502:physiology*; D013045:Species Specificity; D013499:Surface Properties; D014867:Water / Q000494:pharmacology
chemical_list: D014867:Water