First monitoring for unauthorized genetically modified bacteria in food enzymes from the food market

Retrospective surveillance of viable Bacillus cereus group contaminations in commercial food and feed vitamin B2 products sold on the Belgian market using whole-genome sequencing

Bacillus cereus is a spore-forming bacterium that occurs as a contaminant in food and feed, occasionally resulting in food poisoning through the production of various toxins. In this study, we retrospectively characterized viable B. cereus sensu lato (s.l.) isolates originating from commercial vitamin B₂ feed and food additives collected between 2016 and 2022 by the Belgian Federal Agency for the Safety of the Food Chain from products sold on the Belgian market. In total, 75 collected product samples were cultured on a general medium and, in case of bacterial growth, two isolates per product sample were collected and characterized using whole-genome sequencing (WGS) and subsequently characterized in terms of sequence type (ST), virulence gene profile, antimicrobial resistance (AMR) gene profile, plasmid content, and phylogenomic relationships. Viable B. cereus was identified in 18 of the 75 (24%) tested products, resulting in 36 WGS datasets, which were classified into eleven different STs, with ST165 (n = 10) and ST32 (n = 8) being the most common. All isolates carried multiple genes encoding virulence factors, including cytotoxin K-2 (52.78%) and cereulide (22.22%). Most isolates were predicted to be resistant to beta-lactam antibiotics (100%) and fosfomycin (88.89%), and a subset was predicted to be resistant to streptothricin (30.56%). Phylogenomic analysis revealed that some isolates obtained from different products were closely related or even identical indicating a likely common origin, whereas for some products the two isolates obtained did not show any close relationship to each other or other isolates found in other products. This study reveals that potentially pathogenic and drug-resistant B. cereus s.l. can be present in food and feed vitamin B₂ additives that are commercially available, and that more research is warranted to assess whether their presence in these types of products poses a threat to consumers.

Genetically engineered microorganisms for environmental remediation

In the recent era, the increasing persistence of hazardous contaminants is badly affecting the globe in many ways. Due to high environmental contamination, almost every second species on earth facing the worst issue in their survival. Advances in newer remediation approaches may help enhance bioremediation's quality, while conventional procedures have failed to remove hazardous compounds from the environment. Chemical and physical waste cleanup approaches have been used in current circumstances; however, these methods are costly and harmful to the environment. Thus, there has been a rise in the use of bioremediation due to an increase in environmental contamination, which led to the development of genetically engineered microbes (GEMs). It is safer and more cost-effective to use engineered microorganisms rather than alternative methods. GEMs are created by introducing a stronger protein into bacteria through biotechnology or genetic engineering to enhance the desired trait. Biodegradation of oil spills, halobenzoates naphthalenes, toluenes, trichloroethylene, octanes, xylenes etc. has been accomplished using GEMs such bacteria, fungus, and algae. Biotechnologically induced microorganisms are more powerful than naturally occurring ones and may degrade contaminants faster because they can quickly adapt to new pollutants they encounter or co-metabolize. Genetic engineering is a worthy process that will benefit the environment and ultimately the health of our people.

Development of a Taxon-Specific Real-Time PCR Method Targeting the Bacillus subtilis Group to Strengthen the Control of Genetically Modified Bacteria in Fermentation Products

Most of the bacteria that are used to produce fermentation products, such as enzymes, additives and flavorings, belong to the Bacillus subtilis group. Recently, unexpected contaminations with unauthorized genetically modified (GM) bacteria (viable cells and associated DNA) that were carrying antimicrobial resistance (AMR) genes was noticed in several microbial fermentation products that have been commercialized on the food and feed market. These contaminations consisted of GM Bacillus species belonging to the B. subtilis group. In order to screen for the potential presence of such contaminations, in this study we have developed a new real-time PCR method targeting the B. subtilis group, including B. subtilis, B. licheniformis, B. amyloliquefaciens and B. velezensis. The method’s performance was successfully assessed as specific and sensitive, complying with the Minimum Performance Requirements for Analytical Methods of GMO Testing that is used as a standard by the GMO enforcement laboratories. The method’s applicability was also tested on 25 commercial microbial fermentation products. In addition, this method was developed to be compatible with the PCR-based strategy that was recently developed for the detection of unauthorized GM bacteria. This taxon-specific method allows the strengthening of the set of screening markers that are targeting key sequences that are frequently found in GM bacteria (AMR genes and shuttle vector), reinforcing control over the food and feed chain in order to guarantee its safety and traceability.