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Chapter 6
6.9. Main Findings Summary
Previous research examining Salmonella biofilm density has tended to
focus on a limited number of strains of interest [67, 98], with a single
serovar [67, 102, 106, 138, 148, 187-188] or using a single biofilm substrata
[111-112, 165, 191]. However, it is difficult to form well founded
conclusions if the strains are not compared to other strains and serovars
under a variety of conditions and with consideration for repeatability of
findings under a given set of conditions. It is of value to consider the
surfaces commonly found in food processing settings. The work presented
in this thesis enhances the knowledge of Salmonella enterica biofilm
density on surfaces, as multiple strains within three serovars of interest S.
Agona, S. Typhimurium and S. Enteritidis were compared with more
thorough assessment of repeatability than is evident in most published
research.
The main purpose of the current study was to determine if the S. Agona
outbreak strains SAGOXB.0066 formed a more dense biofilm than other
strains of S. Agona and/or other serovars of Salmonella commonly
associated with foodborne outbreaks. The results show no convincing
evidence to demonstrate that the outbreak strain or the variant strain
(related to the outbreak) formed a more dense biofilm than other recent
strains of S. Agona. This was demonstrated using the CBR and the
microtitre plate method.
When the biofilm was developed over 48 hours the results suggest that
Salmonella biofilm density may be related to serovars. The results indicate
that in most cases S. Agona and S. Typhimurium may tend to form a more
dense biofilm than S. Enteritidis. These findings were broadly consistent
when examined using both the CBR and the microtitre plate method.
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