Differences in biofilm formation of Salmonella serovars on two surfaces under two temperature conditions

Abstract

Aims Salmonella is extremely diverse, with >2500 serovars that are genetically and phenotypically diverse. The aim of this study was to build a collection of Salmonella isolates that are genetically diverse and to evaluate their ability to form biofilm under different conditions relevant to a processing environment. Methods and Results Twenty Salmonella isolates representative of 10 serovars were subtyped using Clustered regularly interspaced short palindromic repeats (CRISPR)‐typing to assess the genetic diversity between isolates of each serovar. Biofilm formation of the isolates on both plastic and stainless‐steel surfaces at 25 and 15°C was assessed. At 25°C, 8/20 isolates each produced strong and moderate biofilm on plastic surface compared to stainless‐steel (3/20 and 13/20 respectively). At 15°C, 5/20 produced strong biofilm on plastic surface and none on stainless‐steel. Several isolates produced weak biofilm on plastic (11/20) and stainless‐steel (16/20) surfaces. Serovar Schwarzengrund consistently produced strong biofilm while serovars Heidelberg and Newport produced weak biofilm. Conclusion These results suggest that Salmonellae differ in their attachment depending on the surface and temperature conditions encountered, which may influence persistence in the processing environment. Significance and Impact of Study These differences in biofilm formation could provide useful information for mitigation of Salmonella in processing environments.

Antimicrobial and Antibiofilm Effect of Commonly Used Disinfectants on Salmonella Infantis Isolates

“…Higher biofilm levels observed after longer incubation time ( Figure 1 ) could be attributed to the downregulation of genes responsible for biofilm formation in early biofilm (72 h) and upregulated expression in the mature biofilm [ 32 , 33 ]. As shown before, isolate-to-isolate variability was observed, whereas S. Infantis produced strong biofilm on polystyrene at either 25 °C (48 h) or 15 °C (120 h) [ 34 ]. On the contrary, in the study of Schonewille et al (2012), S .…”

Antimicrobial Tolerance in Salmonella: Contributions to Survival and Persistence in Processing Environments

“…Therefore, the ability of microorganisms to acquire reduced susceptibility to concentrations of antimicrobial compounds with the exception of antibiotics is referred to as 'antimicrobial tolerance' in this section. As previously mentioned, Salmonella has been inactivated at different concentrations of antimicrobials but due to the diversity in Salmonella serotypes and strain-to-strain variation, some serotypes and strains are able to tolerate these concentrations to survive and persist in the processing environment [65]. Food-borne pathogens different environmental changes during food processing, including extreme pH and temperatures, and low levels of antimicrobials that could cause injury or stress [66].…”

Human Salmonellosis: A Continuous Global Threat in the Farm-to-Fork Food Safety Continuum

“…Curlin subunit gene D (CsgD), regulated by transcriptional factors, bis-3 -5 -cyclic dimeric guanosine monophosphate (c-di-GMP), and sRNAs, regulates biofilm formation by Salmonella [86]. The biofilm-forming capacity may vary among serovars [87] but largely depends on various extrinsic factors, including temperature, source, and contact surface [88,89]. In addition, biofilm formation may vary based on their carrier state, i.e., chronic carriage versus sensitive isolates of Salmonella [90].…”