Non-molecular characterization of pellicle formation by poultry Salmonella Kentucky strains and other poultry-associated Salmonella serovars in Luria Bertani broth

Abstract

There is limited research concerning the biofilm-forming capabilities of Salmonella Kentucky, a common poultry isolate. The objective was to quantitate pellicle formation of S. Kentucky versus better-characterized Salmonella strains of Enteritidis and Heidelberg. In separate experiments, Salmonella strains and serovars were tested for their biofilm-forming abilities in different Luria-Bertani (LB) broths (1); pellicle formation in different volumes of LB without salt (2); and the potential priming effects on formation after pellicles were transferred three consecutive times (3). Data were analyzed using One-Way ANOVA with means separated using Tukey’s HSD (P ≤ 0.05). In the first experiment, there was no significant effect between strain and serovars (P > 0.05), but media type affected pellicle formation significantly with LB Miller and LB minus NaCl plus 2% glucose resulting in no pellicle formation (P < 0.001). When grown in 50 mL, Kentucky 38-0085 produced larger pellicles than Kentucky 38-0055, and Heidelberg strain 38-0127 (P < 0.0001). Serial transfers of pellicles did not significantly affect pellicle formation (P > 0.05); however, Kentucky 38-0084, 38-0085 and 38-0086 produced larger pellicles than Kentucky 38-0055 and 38-0056 and Heidelberg 38-0126, 38-0127 and 38-0152. The current study demonstrates the consistent biofilm forming capabilities of Kentucky and may explain why Kentucky is frequently isolated in poultry processing facilities.

Keywords:

• Pellicle
• Salmonella Kentucky
• poultry
• Salmonella enteritidis
• Salmonella Heidelberg

Acknowledgments

The author DKD would like to acknowledge the Graduate College at the University of Arkansas for its support of the research and the continued support from the Center for Advanced Surface Engineering.

Author contributions statement

All authors significantly contributed to the work of the current study. ZS and SCR designed the experiments and ZS conducted the laboratory experiments. DKD and ZS analyzed the data and ZS wrote the manuscript with assistance from DKD and SCR.

Additional information

Funding

The author DKD would like to acknowledge the stipend provided through the Distinguished Academy Fellowship, the National Science Foundation (Grant No. OIA-1457888) and the Arkansas EPSCoR Program, ASSET III.