Phylogenetic Profiles of In-House Microflora in Drains at a Food Production Facility: Comparison and Biocontrol Implications of Listeria-Positive and -Negative Bacterial Populations

Abstract

g Listeria species experience complex interactions with other microorganisms, which may promote growth and colonization of the organism in local environments or negatively affect them. This study investigated the microbial community at a food production facility, examining interactions between Listeria and the associated microbiome. Listeria species can be transferred between zones in the production environment by individuals or equipment, and drains may act as a reservoir for the organism, reflecting the microbial flora potentially in the production environment. Drains that were colonized by Listeria species and those determined to be free of Listeria were examined. In each case, 16S rRNA gene analysis was performed using the PhyloChip platform. Some general similarities in bacterial population structure were observed when Listeria-negative and -positive drain communities were compared, with some distinct differences also noted. These included increased populations of the genera Prevotella and Janthinobacterium associated with the absence of Listeria species, whereas Enterococcus and Rhodococcus were in higher abundance in drains colonized by Listeria species. Based on these results, a selection of bacterial species were grown in coculture biofilm with a Listeria monocytogenes strain identified as having colonized a drain at the facility. Mixed-species biofilm experiments showed that Janthinobacterium inhibited attachment and subsequent biofilm formation of L. monocytogenes; however, Enterococcus gallinarum significantly increased it. The results of this study suggest the microbial community in food processing facilities can impact the colonization of Listeria species and that influencing the microbiome in favor of antilisterial species may reduce the colonization of Listeria species and limit the likelihood of product/process contamination.

Competitive and/or Cooperative Interactions of Listeria monocytogenes With Bacillus cereus in Dual-Species Biofilm Formation

“…On the other hand, the results of Group 3 revealed cooperative interactions with a statistically significant difference (p < 0.05) presenting counts between 6.04 and 5.49 log CFU/cm 2 (Figure 2A), as evidenced by the control group (between 5.50 and 5.87 log CFU/cm 2 ) (Figure 2A). These results demonstrate that the bacterial diversity present in foods may behave differently, thus enabling competitive or cooperative interactions, further corroborating with other studies (Fox et al, 2014).…”

“…A recent study showed that bacteriocin pentocin MQ1 isolated from Lactobacillus pentosus CS2 has a biopreservative potential and presented antibacterial activity against L. monocytogenes and B. cereus (Wayah and Philip, 2018). Another example is the Janthinobacterium species, which inhibit the adhesion and formation of L. monocytogenes in mixed-species biofilms, showing that antilisterial properties can impact the microbiome in food-processing facilities (Fox et al, 2014).…”

Emergence of Antibiotic Resistance in Listeria monocytogenes Isolated from Food Products: A Comprehensive Review

“…and other bacterial genera in the food processing environment. Consequently, this could lead to the evolution of resistance to some types of antimicrobial agents (Allen et al., ; Fox, Solomon, Moore, Wall, & Fanning, ). Also, it was shown that genetic material for antimicrobial resistance were readily transferable from lactic acid bacteria to L. monocytogenes either under laboratory conditions or in fermented whole milk (Toomey, Monaghan, Fanning, & Bolton, ).…”

Intra- and inter-species interactions within biofilms of important foodborne bacterial pathogens

“…In food industry settings, interactions of L. monocytogenes in multi-species communities are likely, with the bacterial flora in food processing plants to include bacteria with the potential to increase or decrease colonization and biofilm formation by L. monocytogenes ( Fox et al, 2014 ). Strains providing enhanced colonization and biofilm formation could contribute to L. monocytogenes persistence in food industry premises and consist a potential food safety risk.…”