Conjugation inhibitors compete with palmitic acid for binding to the conjugative traffic ATPase TrwD, providing a mechanism to inhibit bacterial conjugation.

Bacterial conjugation is a key mechanism by which bacteria acquire antibiotic resistance. Therefore, conjugation inhibitors (COINs) are promising compounds in the fight against the spread of antibiotic resistance genes among bacteria. Unsaturated fatty acids (uFAs) and alkynoic fatty acid derivatives, such as 2-hexadecanoic acid (2-HDA), have been reported previously as being effective COINs. The traffic ATPase TrwD, a VirB11 homolog in plasmid R388, is the molecular target of these compounds, which likely affect binding of TrwD to bacterial membranes. In this work, we demonstrate that COINs are abundantly incorporated into Escherichia coli membranes, replacing palmitic acid as the major component of the membrane. We also show that TrwD binds palmitic acid, thus facilitating its interaction with the membrane. Our findings also suggest that COINs bind TrwD at a site that is otherwise occupied by palmitic acid. Accordingly, molecular docking predictions with palmitic acid indicated that it shares the same binding site as uFAs and 2-HDA, although it differs in the contacts involved in this interaction. We also identified 2-bromopalmitic acid, a palmitate analog that inhibits many membrane-associated enzymes, as a compound that effectively reduces TrwD ATPase activity and bacterial conjugation. Moreover, we demonstrate that 2-bromopalmitic and palmitic acids both compete for the same binding site in TrwD. Altogether, these detailed findings open up a new avenue in the search for effective synthetic inhibitors of bacterial conjugation, which may be pivotal for combating multidrug-resistant bacteria.

Type IV traffic ATPase TrwD as molecular target to inhibit bacterial conjugation.

Bacterial conjugation is the main mechanism responsible for the dissemination of antibiotic resistance genes. Hence, the search for specific conjugation inhibitors is paramount in the fight against the spread of these genes. In this pursuit, unsaturated fatty acids have been found to specifically inhibit bacterial conjugation. Despite the growing interest on these compounds, their mode of action and their specific target remain unknown. Here, we identified TrwD, a Type IV secretion traffic ATPase, as the molecular target for fatty acid-mediated inhibition of conjugation. Moreover, 2-alkynoic fatty acids, which are also potent inhibitors of bacterial conjugation, are also powerful inhibitors of the ATPase activity of TrwD. Characterization of the kinetic parameters of ATPase inhibition has led us to identify the catalytic mechanism by which fatty acids exert their activity. These results open a new avenue for the rational design of inhibitors of bacterial conjugation in the fight against the dissemination of antibiotic resistance genes.

Assessment of the feed additive consisting of Pediococcus pentosaceus DSM 14021 for all animal species for the renewal of its authorisation (Chr. Hansen A/S).

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the assessment of the application for renewal of Pediococcus pentosaceus DSM 14021, a technological additive for all animal species. The applicant has provided evidence that the additive currently on the market complies with the existing conditions of authorisation. The Panel concluded that the additive remains safe for all animal species, consumers and the environment under the authorised conditions of use. Regarding user safety, the Panel considers that any exposure through skin and respiratory tract is considered a risk. The Panel cannot conclude on the eye irritation potential of the additive due to the lack of data. There is no need for assessing the efficacy of the additive in the context of the renewal of the authorisation.

Assessment of the feed additive consisting of Enterococcus lactis DSM 22502 for all animal species for the renewal of its authorisation (Chr. Hansen A/S).

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of Enterococcus lactis DSM 22502 as a technological feed additive for all animal species. The applicant provided evidence that the additive currently on the market complies with the existing conditions of authorisation. There is no new evidence that would lead the FEEDAP Panel to reconsider its previous conclusions regarding the safety and efficacy of the additive. The FEEDAP Panel concluded that E. lactis remains safe for all animal species, consumers and environment under the authorised conditions of use. Regarding the user safety, the Panel concluded that the additive is not irritating to the skin or eyes. No conclusions can be drawn on the potential of the additive to cause skin sensitisation, but it is considered to be a respiratory sensitiser. There is no need for assessing the efficacy of the additive in the context of the renewal of the authorisation.

Assessment of the feed additive consisting of Pediococcus pentosaceus DSM 23689 for all animal species for the renewal of its authorisation (Chr. Hansen A/S).

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the assessment of the application for renewal of the authorisation of Pediococcus pentosaceus DSM 23689 as a technological additive, silage additive for all animal species. The applicant has provided evidence that the additive currently on the market complies with the existing conditions of authorisation. The Panel concluded that the additive remains safe for all animal species, consumers, and the environment under the authorised conditions of use. Regarding user safety, the additive should be considered as a respiratory sensitiser. No conclusions can be drawn on the skin sensitisation, and skin and eye irritancy potential of the additive. There is no need for assessing the efficacy of the additive in the context of the renewal of the authorisation.

Assessment of the feed additive consisting of Pediococcus pentosaceus DSM 23688 for all animal species for the renewal of its authorisation (Chr. Hansen A/S).

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the assessment of the application for renewal of Pediococcus pentosaceus DSM 23688, a technological additive for all animal species. The applicant has provided evidence that the additive currently on the market complies with the existing conditions of authorisation. The Panel concluded that the additive remains safe for all animal species, consumers, and the environment under the authorised conditions of use. Regarding user safety, the additive was shown not to be irritant to skin or eyes. The Panel was not in the position to conclude on skin sensitisation potential of the additive, but it is considered to be a respiratory sensitiser. There is no need for assessing the efficacy of the additive in the context of the renewal of the authorisation.

Assessment of the feed additive consisting of Levilactobacillus brevis DSM 21982 for all animal species for the renewal of its authorisation (Marigot Ltd T/A Celtic Sea Minerals).

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the assessment of the application for renewal of Levilactobacillus brevis DSM 21982 as a technological feed additive, silage additive, for all animal species. The applicant has provided evidence that the additive currently on the market complies with the existing conditions of authorisation. The Panel concluded that the additive remains safe for all animal species, consumers and the environment. Regarding user safety, the additive should be considered as a skin and respiratory sensitiser. No conclusions can be drawn on the eye irritancy potential of the additive. There is no need for assessing the efficacy of the additive in the context of the renewal of the authorisation.

Assessment of the feed additive consisting of Lacticaseibacillus paracasei ATCC PTA-6135 for all animal species for the renewal of its authorisation (Pioneer Hi-Bred International, Inc.).

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the assessment of the application for renewal of authorisation of Lacticaseibacillus paracasei ATCC PTA-6135 as a technological additive (functional group: silage additive) for all animal species. The applicant has provided evidence that the additive currently on the market complies with the existing terms of the of authorisation. The EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) concluded that the active agent L. paracasei ATCC PTA-6135 remains safe for all animal species, consumers and the environment. Regarding user safety, the panel concluded that owing to the nature of the additive, L. paracasei ATCC PTA-6135 should be considered a potential skin and respiratory sensitiser, and any exposure through the skin and respiratory tract is considered a risk. In the absence of data, no conclusion could be drawn on the eye irritation potential of the additive. There is no need for assessing the efficacy of the additive in the context of the renewal of the authorisation.

Safety and efficacy of a feed additive consisting of 6-phytase produced with Trichoderma reesei (CBS 126897) (Quantum® Blue) for fin fish (ROAL Oy).

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of 6-phytase (Quantum® Blue) as a zootechnical feed additive for fin fish. The additive is authorised for use in poultry and pigs. The additive is available in solid and liquid forms, and the 6-phytase contained in the product is produced by fermentation with a genetically modified strain of Trichoderma reesei. The Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) concluded that the genetic modification of the production strain does not give rise to safety concerns; viable cells of the production strain and its DNA were not detected in the final products. The FEEDAP Panel concluded that, based on the data available, the additive tested is safe for fin fish at the highest recommended level of 2500 phytase activity unit (FTU)/kg complete feed. The Panel concluded that Quantum® Blue is not an irritant to skin and eyes nor a skin sensitiser. Owing to the proteinaceous nature of the active substance, 6-phytase (Quantum® Blue) is considered a respiratory sensitiser. The use of Quantum® Blue as a feed additive is considered safe for the environment. The additive is considered to be efficacious as a zootechnical additive for salmonids and ornamental fish at 500 FTU/kg complete feed and other fin fish at 2500 FTU/kg complete feed.

Assessment of the feed additive consisting of Lactiplantibacillus plantarum ATCC 55944 for all animal species for the renewal of its authorisation (Pioneer Hi-Bred International, Inc.).

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the assessment of the application for renewal of Lactiplantibacillus plantarum (formerly Lactobacillus plantarum) ATCC 55944 as a technological additive (functional group: silage additive) for all animal species. The applicant has provided evidence that the additive currently on the market complies with the existing conditions of authorisation. The EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) concluded that the additive remains safe for all animal species, consumer and the environment. Regarding user safety, the Panel concluded that owing to the nature of the additive, Lactiplantibacillus plantarum ATCC 55944 should be considered a potential skin and respiratory sensitiser, and that any exposure through the skin and respiratory tract is considered a risk. The Panel could not conclude on the eye irritation potential of the additive due to the lack of data. There is no need for assessing the efficacy of the additive in the context of the renewal of the authorisation.

Assessment of the feed additive consisting of Lactiplantibacillus plantarum ATCC 55943 for all animal species for the renewal of its authorisation (Pioneer Hi-Bred International, Inc.).

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the assessment of the application for renewal of Lactiplantibacillus plantarum (formerly Lactobacillus plantarum) ATCC 55943 as a technological additive (functional group: silage additive) for all animal species. The applicant has provided evidence that the additive currently on the market complies with the existing conditions of authorisation. The EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) concluded that the additive remains safe for all animal species, consumers and the environment. Regarding user safety, the Panel concluded that owing to the nature of the additive, Lactiplantibacillus plantarum ATCC 55943 should be considered a potential skin and respiratory sensitiser, and any exposure through the skin and respiratory tract is considered a risk. The Panel could not conclude on the eye irritation potential of the additive due to the lack of data. There is no need for assessing the efficacy of the additive in the context of the renewal of the authorisation.

Assessment of the feed additive consisting of Lactiplantibacillus plantarum DSM 18113 for all animal species for the renewal of its authorisation (Pioneer Hi-Bred International, Inc.).

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the assessment of the application for renewal of Lactiplantibacillus plantarum (formerly Lactobacillus plantarum) DSM 18113 as a technological additive (functional group: silage additive) for all animal species. The applicant has provided evidence that the additive currently on the market complies with the existing conditions of authorisation. The EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) concluded that the additive remains safe for all animal species, consumers and the environment. Regarding user safety, the Panel concluded that owing to the nature of the additive, Lactiplantibacillus plantarum DSM 18113 should be considered a potential skin and respiratory sensitiser, and that any exposure through the skin and respiratory tract is considered a risk. The Panel could not conclude on the eye irritation potential of the additive due to the lack of data. There is no need for assessing the efficacy of the additive in the context of the renewal of the authorisation.

Assessment of the feed additive consisting of Lactiplantibacillus plantarum DSM 18112 for all animal species for the renewal of its authorisation (Pioneer Hi-Bred International, Inc.).

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the assessment of the application for renewal of Lactiplantibacillus plantarum (formerly Lactobacillus plantarum) DSM 18112 as a technological additive (functional group: silage additive) for all animal species. The applicant has provided evidence that the additive currently on the market complies with the existing conditions of authorisation. The EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) concluded that the additive remains safe for all animal species, consumers and the environment. Regarding user safety, the Panel concluded that owing to the nature of the additive, Lactiplantibacillus plantarum DSM 18112 should be considered a potential skin and respiratory sensitiser, and that any exposure through the skin and respiratory tract is considered a risk. The Panel could not conclude on the eye irritation potential of the additive due to the lack of data. There is no need for assessing the efficacy of the additive in the context of the renewal of the authorisation.

Assessment of the feed additive consisting of Lactiplantibacillus plantarum DSM 18114 for all animal species for the renewal of its authorisation (Pioneer Hi-Bred International, Inc.).

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the assessment of the application for renewal of Lactiplantibacillus plantarum (formerly Lactobacillus plantarum) DSM 18114 as a technological additive (functional group: silage additive) for all animal species. The applicant has provided evidence that the additive currently on the market complies with the existing conditions of authorisation. The EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) concluded that the additive remains safe for all animal species, consumer and the environment. Regarding user safety, the Panel concluded that owing to the nature of the additive, Lactiplantibacillus plantarum DSM 18114 should be considered a potential skin and respiratory sensitiser, and that any exposure through the skin and respiratory tract is considered a risk. The Panel could not conclude on the eye irritation potential of the additive due to the lack of data. There is no need for assessing the efficacy of the additive in the context of the renewal of the authorisation.

Assessment of the feed additive consisting of Limosilactobacillus fermentumNCIMB 30169 for all animal species for the renewal of its authorisation (Microferm Ltd.).

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the assessment of the application of renewal of Limosilactobacillus fermentum NCIMB 30169 as a technological feed additive (functional group: silage additives) for all animal species. The applicant has provided evidence that the additive currently on the market complies with the existing terms of the authorisation. The EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) concluded that the additive remains safe for all animal species, consumers, and the environment. Regarding user safety, the additive should be considered a skin and respiratory sensitiser. No conclusions can be drawn on the eye irritancy potential of the additive. There is no need for assessing the efficacy of the additive in the context of the renewal of the authorisation.

Assessment of the feed additive consisting of Lentilactobacillus buchneriATCC PTA-6138 for all animal species for the renewal of its authorisation (Pioneer Hi-Bred International, Inc.).

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the assessment of the application for renewal of Lentilactobacillus buchneri ATCC PTA-6138 as a technological additive (functional group: silage additives) for all animal species. The applicant has provided evidence that the additive currently on the market complies with the existing terms of the authorisation. The EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) concluded that the additive remains safe for all animal species, consumers and the environment. Regarding user safety, the additive should be considered as a skin and respiratory sensitiser. No conclusions could be drawn on the eye irritancy potential of the additive. There is no need for assessing the efficacy of the additive in the context of the renewal of the authorisation.

Assessment of the feed additive consisting of Lentilactobacillus buchneriATCC PTA-2494 for all animal species for the renewal of its authorisation (Pioneer Hi-Bred International, Inc.).

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the assessment of the application for renewal of Lentilactobacillus buchneri ATCC PTA-2494 as a technological additive (functional group: silage additives) for all animal species. The applicant has provided evidence that the additive currently on the market complies with the existing terms of the authorisation. The EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) concluded that the additive remains safe for all animal species, consumers and the environment. Regarding user safety, the Panel considers that any exposure through skin and respiratory tract is considered a risk. The Panel cannot conclude on the eye irritation potential of the additive due to the lack of data. There is no need for assessing the efficacy of the additive in the context of the renewal of the authorisation.

Assessment of the feed additive consisting of Lentilactobacillus buchneri (formerly Lactobacillus buchneri) DSM 22501 for all animal species for the renewal of its authorisation (Chr. Hansen A/S).

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the assessment of the application for renewal of the authorisation of the additive consisting of Lentilactobacillus buchneri DSM 22501 as a technological feed additive to improve ensiling of fresh material for all animal species. The applicant has provided evidence that the additive currently on the market complies with the existing conditions of authorisation. There is no new evidence that would lead the FEEDAP Panel to reconsider its previous conclusions. Thus, the Panel concludes that the additive remains safe for all animal species, consumer and the environment under the authorised conditions of use. Regarding user safety, the additive is not irritant to skin and eye, but owing to its proteinaceous nature it should be considered a respiratory sensitiser. No conclusions could be drawn on the skin sensitisation potential of the additive. There is no need for assessing the efficacy of the additive in the context of the renewal of the authorisation.

Safety and efficacy of a feed additive consisting of Lentilactobacillus diolivorans (formerly Lactobacillus diolivorans) DSM 33625 as a silage additive for all animal species (Lactosan GmbH & Co.KG).

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on Lentilactobacillus diolivorans (formerly Lactobacillus diolivorans) DSM 33625 when used as a technological additive to improve ensiling of forage. The additive is intended for use with all forages and for all animal species at a proposed minimum concentration of 1 × 108 colony forming units (CFU)/kg forage. The bacterial species L. diolivorans is considered by EFSA to be suitable for the qualified presumption of safety approach to safety assessment. As the identity of the strain has been clearly established and no acquired antimicrobial resistance determinants of concern were detected, the use of the strain as a silage additive is considered safe for livestock species, for consumers of products from animals fed the treated silage and for the environment. The additive is not a skin or an eye irritant. In the absence of data, no conclusion can be drawn on the skin sensitisation of the additive. Given the proteinaceous nature of the active agent, the additive should be considered a respiratory sensitiser. The FEEDAP Panel concluded that Lentilactobacillus diolivorans DSM 33625 at a minimum concentration of 1 × 108 CFU/kg forage may extend the aerobic stability of silage prepared from easy and moderately difficult to ensile forage material with a DM range of 32-65%.

Assessment of the feed additive consisting of Pediococcus pentosaceusDSM 23376 for all animal species for the renewal of its authorisation (Agri-King, Inc.).

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the assessment of the application for renewal of Pediococcus pentosaceus DSM 23376, as a technological additive to improve ensiling of forage for all animal species. The applicant has provided evidence that the additive currently on the market complies with the existing conditions of authorisation. There is no new evidence that would lead the FEEDAP Panel to reconsider its previous conclusions. Thus, the Panel concludes that the additive remains safe for all animal species, consumers and the environment under the authorised conditions of use. Regarding user safety, the additive is not irritant to skin or eyes but owing to its proteinaceous nature, it should be considered a respiratory sensitiser. No conclusions can be drawn on the skin sensitisation potential of the additive. There is no need for assessing the efficacy of the additive in the context of the renewal of the authorisation.