Abstract
BackgroundBiofilm has been shown to be one way for Salmonella to persist in the feed factory environment. Matrix components, such as fimbriae and cellulose, have been suggested to play an important role in the survival of Salmonella in the environment. Multicellular behaviour by Salmonella is often categorized according to colony morphology into rdar (red, dry and rough) expressing curli fimbriae and cellulose, bdar (brown, dry and rough) expressing curli fimbriae and pdar (pink, dry and rough) expressing cellulose.The aim of the study was to look into the distribution of morphotypes among feed and fish meal factory strains of Salmonella, with emphasis on potential differences between morphotypes with regards to survival in the feed factory environment.ResultsWhen screening a total of 148 Salmonella ser. Agona, Salmonella ser. Montevideo, Salmonella ser. Senftenberg and Salmonella ser. Typhimurium strains of feed factory, human clinical and reference collection origin, as many as 99% were able to express rough morphology (rdar or bdar). The dominant morphotype was rdar (74%), however as many as 55% of Salmonella ser. Agona and 19% of Salmonella ser. Senftenberg displayed the bdar morphology.Inconsistency in Calcofluor binding, indicating expression of cellulose, was found among 25% of all the strains tested, however Salmonella ser. Agona showed to be highly consistent in Calcofluor binding (98%).In biofilm, Salmonella ser. Agona strains with bdar mophology was found to be equally tolerant to disinfection treatment as strains with rdar morphotype. However, rdar morphology appeared to be favourable in long term survival in biofilm in a very dry environment.Chemical analysis showed no major differences in polysaccharide content between bdar and rdar strains. Our results indicate that cellulose is not a major component of the Salmonella biofilm matrix.ConclusionThe bdar morphotype is common among Salmonella ser. Agona strains isolated from the factory environment. The rdar and the bdar strains were found to be equally tolerant to disinfectants, while the rdar strain was found to be more tolerant to long-term desiccation and nutrient depletion in biofilm than the bdar strain. Cellulose does not appear to be a major component of the Salmonella biofilm matrix.
Highlights
Biofilm has been shown to be one way for Salmonella to persist in the feed factory environment
Typhimurium strains of feed factory, human clinical and reference collection origin, as many as 99% were able to express rough morphology
The bdar morphotype is common among Salmonella ser
Summary
Biofilm has been shown to be one way for Salmonella to persist in the feed factory environment Matrix components, such as fimbriae and cellulose, have been suggested to play an important role in the survival of Salmonella in the environment. Biofilm has been shown to be a way for Salmonella to persist in the feed and fish meal factory environment [5]. Several physiological changes like altered growth rate and transcription of different genes have been observed among bacteria in biofilms [8] Biofilms are both medically and industrially important because they can accumulate on a wide variety of substrates, and bacteria in biofilms are more resistant to antimicrobial agents than their planktonic counterparts [7,9,10]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
