Control ofSalmonellaEnteritidis on food contact surfaces with bacteriophage PVP-SE2

Abstract

Salmonella is one of the worldwide leading foodborne pathogens responsible for illnesses and hospitalizations, and its capacity to form biofilms is one of its many virulence factors. This work evaluated (bacterio)phage control of adhered and biofilm cells of Salmonella Enteritidis on three different substrata at refrigerated and room temperatures, and also a preventive approach in poultry skin. PVP-SE2 phage was efficient in reducing both 24-and 48-h old Salmonella biofilms from polystyrene and stainless steel causing 2 to 5 log CFU cm À2 reductions with a higher killing efficiency at room temperature. PVP-SE2 phage application on poultry skins reduced levels of Salmonella. Freezing phage-pretreated poultry skin samples had no influence on the viability of phage PVP-SE2 and their in vitro contamination with S. Enteritidis provided evidence that phages prevented their further growth. Although not all conditions favor phage treatment, this study endorses their use to prevent and control foodborne pathogen colonization of surfaces.

Entrapment of a phage cocktail and cinnamaldehyde on sodium alginate emulsion-based films to fight food contamination by Escherichia coli and Salmonella Enteritidis

“…This major difference in viable cell reductions was not expected, since both phages have fairly similar burst sizes with EC4 reaching approximately 132 PFU per infected bacteria ( Fig. 1) and φ135 resulting in about 163 PFU per infected cell (Milho, 2019). There are, however, differences in the length of the latent periods, with EC4 presenting a shorter period (5 min) than φ135 (30 min) (Milho, 2019), respectively (Fig.…”

“…1) and φ135 resulting in about 163 PFU per infected cell (Milho, 2019). There are, however, differences in the length of the latent periods, with EC4 presenting a shorter period (5 min) than φ135 (30 min) (Milho, 2019), respectively (Fig. 1c).…”

“…The phages used in this work were the Salmonella phage φ135 and E. coli phage EC4. Phage φ135 has been previously characterized and belongs to the Siphoviridae family with a long non-contractile tail (Milho, 2019;Sillankorva et al, 2010). This phage forms clear plaques on its host bacterium, has a latent period of approximately 30 min and a burst size of 162.9 particles per infected cell (Milho et al, 2018).…”

Escherichia coli and Salmonella Enteritidis dual-species biofilms: interspecies interactions and antibiofilm efficacy of phages

“…After, all cultures were diluted to 1 × 10 7 CFU/mL, and 200 μL/well of culture transferred to polystyrene microtiter plates (96-well flat-bottom, Sarstedt, Inc., Germany) and incubated at 37 °C (48 h, 120 rpm). After, biofilms were washed twice with saline and detached using an ultrasonic bath (50 kHz, 6 min, Sonicor SC-52, Sonicor Instruments, UK) 53 . Bacterial suspensions were homogenized, 10-fold serially diluted, and plated onto solid LB supplemented with either kanamycin or ampicillin, and incubated overnight at 37 °C.…”

Reduction of Salmonella contamination on the surface of chicken skin using bacteriophage

“…If the chickens that arrive at the abattoir are carrying Salmonella , they will almost inevitably produce contaminated carcasses. In the present study, the use of commercial chickens experimentally colonised with Salmonella would be expected to result in a more realistic distribution of the pathogen across the carcass surface than, for example, sections of skin inoculated with a suspension of bacteria, which are models which have been used in previous studies [ 50 , 51 ].…”