View/Open - ARAN - National University of Ireland, Galway

Chapter 2
2.8. Summary
All 13 strains were able to form a biofilm after 48 hours; this may have
serious implications for the food industry, who may choose surfaces such
as stainless steel as a food contact surface due to ability to clean the
surface.
It is evident from the results that tile consistently supported more dense
biofilm formation across the 13 strains. This has not been reported
elsewhere although tile has been shown to allow attachment and transfer
of S. Typhimurium to foods [192].
To summarise S. enterica biofilm formation may be dependent on serotype,
substratum and possibly the origin of the sample may play a role. However
the evidence if anything suggests that the outbreak strain S. Agona
SAGOXB.0066 has a lesser propensity for biofilm formation although given
the extent of intra-run variation it is uncertain how much weight can be
give to the apparent differences.
The broad range on differences on repeated values of testing the strains on
the same surfaces highlights that caution should be used when assigning
practical significance to minor differences observed in laboratory models.
However it is important to highlight that this variance is similar to what has
been reported elsewhere using the CBR, including the manufacturers of the
model who devised the optimum conditions for the biofilm development.
However, on a number of occasions the work described in previous
literature does not incorporate a large range of multiple runs. Perhaps one
of the key findings from this work is that due to inter-run variability, the
experiments should be replicated on a number of occasions to determine
the accuracy of the findings.
Page 87