Investigating the Growth Abilities of Foodborne Staphylococcus aureus or Escherichia coli in Co-culture with Lactobacilli

Bacterial co-culture assays can improve research of cell-to-cell relationships. These relationships can be seen and relevant in complex microbiomes or food products. To enhance better comprehending of the complicated relationships included, it might be helpful to improve experimental assays that better reproduce the conditions related in vivo. To begin with, this includes designing and selecting a medium that have ability to promote co-culture of the microbial species of interest. The main objective of the research was to design the requirements for co-culture of foodborne pathogens (Staphylococcus aureus or Escherichia coli) and lactic acid bacteria (LAB) species and a follow-on technique to enable monitoring of growth and population dynamics in mixed cultures. Incubation behaviours in mono- and co-culture were determined in agar and broth by scoring colony growth and by Gram-staining. The impacts of adjustments and attachments in MRS media on S. aureus and LAB incubation were determined. Different types of standard media were evaluated; MRS media were found to support the growth of S. aureus and LAB in co-culture and only LAPT media were to be found to support of E. coli and LAB in co-culture. E. coli was considerably grown only in LAPT agar and broth, which also promoted LAB growth. In summary, requirements for co-culture of S. aureus and L. casei in MRS media and co-culture of E. coli and L. casei on LAPT were determined, enabling suitable techniques to observe viable bacterial cells in co-culture. Overall, the results indicate that establishing co-culture conditions is difficult, but applicable for particular bacterial species mixture.