Title
Exploring the occurrence of Listeria in biofilms and deciphering the bacterial community in a frozen vegetable producing environment
Language
English
Description (en)
The establishment of Listeria (L.) monocytogenes within food processing environments constitutes a significant public health concern. This versatile bacterium demonstrates an exceptional capacity to endure challenging environmental conditions in the food processing environment, where contamination of food products regularly occurs. The diverse repertoire of stress resistance genes, the potential to colonize biofilms, and the support of a co-existing microbiota have been proposed as root causes for the survival of L. monocytogenes in food processing environments. In this study, 71 sites were sampled after cleaning and disinfection in a European frozen vegetable processing facility, where L. monocytogenes in-house clones persisted for years. L. monocytogenes and L. innocua were detected by a culture-dependent method at 14 sampling sites, primarily on conveyor belts and associated parts. The presence of biofilms, as determined by the quantification of bacterial load and the analysis of extracellular matrix components (carbohydrates, proteins, extracellular DNA) was confirmed at nine sites (12.7%). In two cases, L. innocua was detected in a biofilm. Furthermore, we explored the resident microbial community in the processing environment and on biofilm-positive sites, as well as the co-occurrence of bacterial taxa with Listeria by 16S rRNA gene sequencing. Pseudomonas, Acinetobacter, and Exiguobacterium dominated the microbial community of the processing environment. Using differential abundance analysis, amplicon sequence variants (ASVs) assigned to Enterobacterales (Enterobacter, Serratia, unclassified Enterobacteriaceae) and Carnobacterium were found to be significantly higher abundant in Listeria-positive samples. Several Pseudomonas ASVs were less abundant in Listeria-positive compared to Listeria-negative samples. Acinetobacter, Pseudomonas, Janthinobacterium, Brevundimonas, and Exiguobacterium were key players in the microbial community in biofilms, and Exiguobacterium and Janthinobacterium were more relatively abundant in biofilms. Further, the microbial composition varied between the different areas and the surface materials.
Keywords (en)
Food-Industry; Monocytogenes; Identification; Diversity; Surfaces; Stress; Gene; Resistance; Microbiota; Abundance
DOI
10.3389/fmicb.2024.1404002
Author of the digital object
Nadja  Pracser  (Austrian Competence Centre for Feed and Food Quality, Safety and Innovation)
Kathrin  Rychli  (University of Veterinary Medicine Vienna)
Martin  Wagner  (University of Veterinary Medicine Vienna / Austrian Competence Centre for Feed and Food Quality, Safety and Innovation)
Evelyne  Selberherr  (University of Veterinary Medicine Vienna)
Ariane  Pietzka  (Austrian Agency for Health and Food Safety)
Eva M.  Voglauer  (Austrian Competence Centre for Feed and Food Quality, Safety and Innovation)
Sarah  Thalguter  (Austrian Competence Centre for Feed and Food Quality, Safety and Innovation)
Format
application/pdf
Size
3.9 MB
Licence Selected
CC BY 4.0 International
Type of publication
Article
Name of Publication (en)
Frontiers in Microbiology
Pages or Volume
15
Volume
15
Publisher
Frontiers Media Sa
Publication Date
2024
Content
Details
Object type
PDFDocument
Format
application/pdf
Created
05.09.2024 09:33:46
This object is in collection
Metadata
Veterinärmedizinische Universität Wien (Vetmeduni) | Veterinärplatz 1 | 1210 Wien - Österreich | T +43 1 25077-0 | Web: vetmeduni.ac.at