Scientific Opinion on the maintenance of the list of QPS biological agents intentionally added to food and feed (2010 update)

Tackling transmission of infectious diseases: A probiotic-based system as a remedy for the spread of pathogenic and resistant microbes

Built environments (BEs) currently represent the areas in which human beings spend most of their life. Consistently, microbes populating BEs mostly derive from human occupants and can be easily transferred from BE to occupants. The hospital microbiome is a paradigmatic example, representing a reservoir for harmful pathogens that can be transmitted to susceptible patients, causing the healthcare-associated infections (HAIs). Environmental cleaning is a crucial pillar in controlling BE pathogens and preventing related infections, and chemical disinfectants have been largely used so far towards this aim. However, despite their immediate effect, chemical-based disinfection is unable to prevent recontamination, has a high environmental impact, and can select/increase antimicrobial resistance (AMR) in treated microbes. To overcome these limitations, probiotic-based sanitation (PBS) strategies were recently proposed, built on the use of detergents added with selected probiotics able to displace surrounding pathogens by competitive exclusion. PBS was reported as an effective and low-impact alternative to chemical disinfection, providing stable rebalance of the BE microbiome and significantly reducing pathogens and HAIs compared to disinfectants, without exacerbating AMR and pollution concerns. This minireview summarizes the most significant results obtained by applying PBS in sanitary and non-sanitary settings, which overall suggest that PBS may effectively tackle the infectious risk meanwhile preventing the further spread of pathogenic and resistant microbes.

The Effect of a Bacillus-Based Probiotic on Sow and Piglet Performance in Two Production Cycles

The aim of this study was to assess the impact of Bacillus-based probiotic diets on reproduction performance, fecal scores, microflora, and economic factors in lactating sows and suckling piglets across two productive cycles. A total of 96 sows, reared in a continuous farrowing system for two full cycles, were divided into two groups: a control group and an experimental group. Sows were fed a basal diet without the probiotic or a diet supplemented with viable bacterial spores. At seven days of age, control group piglets were offered standard creep feed, whereas piglets in the experimental (probiotic) group received a diet containing the probiotic fed to their dams. Sows receiving probiotic-supplemented diets were characterized by significantly higher (p ≤ 0.05) average daily feed intake in lactation, lower (p ≤ 0.01) body weight (BW) loss during lactation, and reduced loss of backfat thickness as well as higher body condition score after lactation. Dietary probiotic supplementation increased (p ≤ 0.01) birth weight, total creep feed consumption, litter weight gain, and piglet weaning weight. The probiotic also improved (p ≤ 0.01) overall fecal scores, decreased total E. coli count on day seven and Clostridium perfringens count (trend) in sucking piglets. The total feed cost per weaned piglet was lower in the experimental (probiotic) group. Supplementing the diet with a probiotic containing Bacillus strains improved the reproductive performance of sows and the performance and health of piglets.

Safety Assessment Systems for Microbial Starters Derived from Fermented Foods

Microorganisms involved in food fermentation not only improve the aroma and taste of the food, but also enhance its preservation. Thus, they are added as starter cultures to boost the final product quality of commercial fermented foods. Although these microorganisms originate from fermented foods and have a long history of consumption, the European Union recently applied the concept of Qualified presumption of Safety (QPS), which is a safety evaluation system for microorganisms used in food or feed in Europe. The QPS system is a species-level safety system and shares results with the European Novel Food System, a strain-level safety evaluation system. In the United States, microorganisms added to fermented foods are considered as food additives or Generally Recognized as Safe substance. In Korea, food microbe lists are presented at the species level. Moreover, the nation has established a strain-oriented evaluation system that applies temporary safety evaluation methods for food raw materials as well as new raw materials. However, when it comes to microorganisms isolated from traditional fermented foods and other fermented food products, there is no definition of the term "species," and there is a lack of an evaluation system at the species level. Therefore, such an evaluation system for microbial species used in Korean fermented foods is necessary.

Bacillus subtilis extracellular polymeric substances conditioning layers inhibit Escherichia coli adhesion to silicon surfaces: A potential candidate for interfacial antifouling additives

Biofouling on material surfaces is a ubiquitous problem in a variety of fields. In aqueous environments, the process of biofouling initiates with the formation of a layer of macromolecules called the conditioning layer on the solid-liquid interface, followed by the adhesion and colonization of planktonic bacteria and the subsequent biofilm development and maturation. In this study, the extracellular polymeric substances (EPS) secreted by Bacillus subtilis were collected and used to prepare conditioning layers on inert surfaces. The morphologies and antifouling performances of the EPS conditioning layers were investigated. It was found that the initial adhesion of Escherichia coli was inhibited on the surfaces precoated with EPS conditioning layers. To further explore the underlying antifouling mechanisms of the EPS conditioning layers, the respective roles of two constituents of B. subtilis EPS (γ-polyglutamic acid and surfactin) were investigated. This study has provided the possibility of developing a novel interfacial antifouling additive with the advantages of easy preparation, nontoxicity, and environmental friendliness.

An Innovative Strategy for the Effective Reduction of MDR Pathogens from the Nosocomial Environment

Antimicrobial resistance (AMR) is currently one of the main concerns for human health.Due to its rapid increase and global diffusion, several common microbial infections might become not curable in the future decades, making it impossible to apply other lifesaver therapies, such as transplant or chemotherapy.AMR is frequently observed in hospital pathogens, due to selective pressure exerted by antibiotic use, and consistently with this, in the recent years, many actions have been proposed to limit AMR spread, including hygiene measures for hospital professionals and a wiser antibiotic usage.Indeed, the hospital environment itself represents a reservoir of pathogens, whose control was so far addressed by conventional sanitation procedures, which however cannot prevent recontamination and might further favour the selection of resistant strains.Here we report the results collected by studying an innovative sanitation strategy based on the use of probiotic bacteria, capable of reducing in a stable way the surface load of pathogens and their AMR. Collected data suggest that this system might contribute significantly to AMR control and might be thus considered as one of the tools for AMR and infection prevention and control.

Safety of Novel Microbes for Human Consumption: Practical Examples of Assessment in the European Union

Novel microbes are either newly isolated genera and species from natural sources or bacterial strains derived from existing bacteria. Novel microbes are gaining increasing attention for the general aims to preserve and modify foods and to modulate gut microbiota. The use of novel microbes to improve health outcomes is of particular interest because growing evidence points to the importance of gut microbiota in human health. As well, some recently isolated microorganisms have promise for use as probiotics, although in-depth assessment of their safety is necessary. Recent examples of microorganisms calling for more detailed evaluation include Bacteroides xylanisolvens, Akkermansia muciniphila, fructophilic lactic acid bacteria (FLAB), and Faecalibacterium prausnitzii. This paper discusses each candidate's safety evaluation for novel food or novel food ingredient approval according to European Union (EU) regulations. The factors evaluated include their beneficial properties, antibiotic resistance profiling, history of safe use (if available), publication of the genomic sequence, toxicological studies in agreement with novel food regulations, and the qualified presumptions of safety. Sufficient evidences have made possible to support and authorize the use of heat-inactivated B. xylanisolvens in the European Union. In the case of A. muciniphila, the discussion focuses on earlier safety studies and the strain's suitability. FLAB are also subjected to standard safety assessments, which, along with their proximity to lactic acid bacteria generally considered to be safe, may lead to novel food authorization in the future. Further research with F. prausnitzii will increase knowledge about its safety and probiotic properties and may lead to its future use as novel food. Upcoming changes in EUU Regulation 2015/2283 on novel food will facilitate the authorization of future novel products and might increase the presence of novel microbes in the food market.

Effect of Bacillus subtilis and Bacillus licheniformis supplementation in diets with low- and high-protein content on ileal crude protein and amino acid digestibility and intestinal microbiota composition of growing pigs

Background

Bacillus spp. seem to be an alternative to antimicrobial growth promoters for improving animals’ health and performance. However, there is little information on the effect of Bacillus spp. in combination with different dietary crude protein (CP) levels on the ileal digestibility and microbiota composition. Therefore, the objective of this study was to determine the effect of Bacillus spp. supplementation to low- (LP) and high-protein diets (HP) on ileal CP and amino acid (AA) digestibility and intestinal microbiota composition.

Methods

Eight ileally cannulated pigs with an initial body weight of 28.5 kg were randomly allocated to a row-column design with 8 pigs and 3 periods of 16 d each. The assay diets were based on wheat-barley-soybean meal with two protein levels: LP (14% CP, as-fed) and HP diet (18% CP, as-fed). The LP and HP diets were supplemented with or without Bacillus spp. at a level of 0.04% (as-fed). The apparent ileal digestibility (AID) and standardized ileal digestibility (SID) of CP and AA was determined. Bacterial community composition from ileal digesta was analyzed by Illumina amplicon sequencing and quantitative real-time PCR. Data were analyzed as a 2 × 2 factorial design using the GLIMMIX procedures of SAS.

Results

The supplementation with Bacillus spp. did not affect both AID and SID of CP and AA in growing pigs. Moreover, there was no difference in AID of CP and AA between HP and LP diets, but SID of cystine, glutamic acid, glycine, and proline was lower (P < 0.05) in pigs fed the HP diets. The HP diets increased abundance of Bifidobacterium spp. and Lactobacillus spp., (P < 0.05) and by amplicon sequencing the latter was identified as predominant genus in microbiota from HP with Bacillus spp., whereas dietary supplementation of Bacillus spp. increased (P < 0.05) abundance of Roseburia spp..

Conclusions

The HP diet increased abundance of Lactobacillus spp. and Bifidobacterium spp.. The supplementation of Bacillus spp. resulted in a higher abundance of healthy gut associated bacteria without affecting ileal CP and AA digestibility, whereas LP diet may reduce the flow of undigested protein to the large intestine of pigs.

Scientific Opinion on the update of the list of QPS-recommended biological agents intentionally added to food or feed as notified to EFSA

EFSA is requested to assess the safety of a broad range of biological agents in the context of notification for market authorisation as sources of food and feed additives, food enzymes and plant protection products. The qualified presumption of safety (QPS) assessment was developed to provide a harmonised generic pre-assessment to support safety risk assessments performed by EFSA's scientific Panels. The safety of unambiguously defined biological agents (at the highest taxonomic unit appropriate for the purpose for which an application is intended), and the completeness of the body of knowledge are assessed. Identified safety concerns for a taxonomic unit are, where possible and reasonable in number, reflected as 'qualifications' in connection with a recommendation for a QPS status. The list of QPS recommended biological agents was reviewed and updated in the current opinion and therefore becomes the valid list. The 2016 update reviews previously assessed microorganisms including bacteria, yeasts and viruses used for plant protection purposes following an Extensive Literature Search strategy. The taxonomic units related to the new notifications received since the 2013 QPS opinion, were periodically evaluated for a QPS status and the results published as Statements of the BIOHAZ Panel. Carnobacterium divergens, Lactobacillus diolivorans, Microbacterium imperiale, Pasteuria nishizawae, Pediococcus parvulus, Bacillus flexus, Bacillus smithii, Xanthomonas campestris and Candida cylindracea were recommended for the QPS list. All taxonomic units previously recommended for the 2013 QPS list had their status reconfirmed as well their qualifications with the exception of Pasteuria nishizawae for which the qualification was removed. The exclusion of filamentous fungi and enterococci from the QPS evaluations was reconsidered but monitoring will be maintained and the status will be re-evaluated in the next QPS Opinion update. Evaluation of bacteriophages should remain as a case-by-case procedure and should not be considered for QPS status.

Effects of Brevibacillus brevis FJAT-1501-BPA on growth performance, faecal microflora, faecal enzyme activities and blood parameters of weaned piglets

A feeding expriment was performed to investigate the effects of dietary supplementation with Brevibacillus brevis FJAT-1501-BPA fermentation on the growth performance, faecal microflora, faecal enzyme activities and blood parameters of weaned piglets. A total of 150 weaned piglets were randomly assigned to different treatments groups, which were fed the same basic diet supplemented with 10, 1, 0.1, 0.01 and 0 % B. brevis FJAT-1501-BPA fermentation. The results showed that a diet supplemented with 10 % B. brevis FJAT-1501-BPA fermentation could significantly increase the final body weight (P < 0.05) and decrease feed to gain ratio, which was 37.1 % lower than that of the control group. The addition of B. brevis FJAT-1501-BPA exhibited a trend of reducing the contents of the Escherichia coli, Lactobacillus and Salmonella compared with the control. During the 35 day experimental period, cellulase and protease activities were significantly increased by the dietary inclusion of the B. brevis FJAT-1501-BPA fermentation (P < 0.05). The cellulase activity for piglets fed diet containing 1 % B. brevis FJAT-1501-BPA fermentation, 21.8 U/g, was highest among the different treatments. The protease activity for piglets fed diet containing 10 % B. brevis FJAT-1501-BPA fermentation, 50.4 U/g, was highest among the different treatments. The amylase and hemicellulase activities for piglets fed diet containing 10 % B. brevis FJAT-1501-BPA fermentation were significantly higher than those on the control diet and other treatments (P < 0.05). Moreover, usage of feed dietary supplementation with B. brevis FJAT-1501-BPA had positive effects on levels of enzymes and minerals in blood. The alkaline phosphatase, alanine aminotransferase, Fe and Mg concentrations for weaned piglets fed diet containing B. brevis FJAT-1501-BPA fermentation were significantly higher than for those on the control diet (P < 0.05). Furthermore, concentration of IgG in serum was higher in weaned piglets fed diet containing 1 % B. brevis FJAT-1501-BPA fermentation compared to other treatments. These results indicated that feeding with B. brevis FJAT-1501-BPA has the potential to improve growth performance, faecal microflora, faecal enzyme activities and blood parameters of weaned piglets.

Characterization of Bacillus spp. strains for use as probiotic additives in pig feed

Bacillus spp. are commonly used as probiotic species in the feed industry, however, their benefits need to be confirmed. This study describes a high throughput screening combined with the detailed characterization of endospore-forming bacteria with the aim to identify new Bacillus spp. strains for use as probiotic additives in pig feed. A total of 245 bacterial isolates derived from African fermented food, feces and soil were identified by 16S rRNA gene sequencing and screened for antimicrobial activity and growth in the presence of antibiotics, bile salts and at pH 4.0. Thirty-three Bacillus spp. isolates with the best characteristics were identified by gyrB and rpoB gene sequencing as B. amyloliquefaciens subsp. plantarum, B. amyloliquefaciens subsp. amyloliquefaciens, B. subtilis subsp. subtilis, B. licheniformis, B. mojavensis, B. pumilus and B. megaterium. These isolates were further investigated for their activity against the pathogenic bacteria, antibiotic susceptibility, sporulation rates, biofilm formation and production of glycosyl hydrolytic enzymes. Additionally, ten selected isolates were assessed for heat resistance of spores and the effect on porcine epithelial cells IPEC-J2. Isolates of B. amyloliquefaciens, B. subtilis and B. mojavensis, showed the best overall characteristics and, therefore, potential for usage as probiotic additives in feed. A large number of taxonomically diverse strains made it possible to reveal species and subspecies-specific trends, contributing to our understanding of the probiotic potential of Bacillus species.