Phenoxaphosphonium Mixed Ylides in Ring Expansion Reaction.

Treatment of mixed phosphonium-iodonium ylides featuring a six-membered phenoxaphosphonium fragment with aqueous tetrafluoroboronic acid induces a rearrangement, resulting in expansion of the phosphacycle and oxidation of the phosphorus atom. The target difficult-to-access dibenzo[b,f][1,4]oxaphosphepine oxides (3 examples) were isolated in excellent yields (up to 95%) as mixtures of stereoisomers. Hydrolysis of a five-membered mixed ylide, a dibenzophosphole derivative, predominantly preserves the phosphole system with cycle expansion occurring as a side process.

Broadening access to small-molecule parameterization with the force field toolkit.

Access to accurate force-field parameters for small molecules is crucial for computational studies of their interactions with proteins. Although a number of general force fields for small molecules exist, e.g., CGenFF, GAFF, and OPLS, they do not cover all common chemical groups and their combinations. The Force Field Toolkit (ffTK) provides a comprehensive graphical interface that streamlines the development of classical parameters for small molecules directly from quantum mechanical (QM) calculations, allowing for force-field generation for almost any chemical group and validation of the fit relative to the target data. ffTK relies on supported external software for the QM calculations, but it can generate the necessary QM input files and parse and analyze the QM output. In previous ffTK versions, support for Gaussian and ORCA QM packages was implemented. Here, we add support for Psi4, an open-source QM package free for all users, thereby broadening user access to ffTK. We also compare the parameter sets obtained with the new ffTK version using Gaussian, ORCA, and Psi4 for three molecules: pyrrolidine, n-propylammonium cation, and chlorobenzene. Despite minor differences between the resulting parameter sets for each compound, most prominently in the dihedral and improper terms, we show that conformational distributions sampled in molecular dynamics simulations using these parameter sets are quite comparable.

IFN-γ-dependent interactions between tissue-intrinsic γδ T cells and tissue-infiltrating CD8 T cells limit allergic contact dermatitis.

BACKGROUND: Elicitation of allergic contact dermatitis (ACD), an inflammatory type 4 hypersensitivity disease, induces skin infiltration by polyclonal effector CD8 αß T cells and precursors of tissue-resident memory T (TRM) cells. Because TRM have long-term potential to contribute to body-surface immunoprotection and immunopathology, their local regulation needs a fuller understanding. OBJECTIVE: We sought to investigate how TRM-cell maturation might be influenced by innate-like T cells pre-existing within many epithelia. METHODS: This study examined CD8+ TRM-cell maturation following hapten-induced ACD in wild-type mice and in strains harboring altered compartments of dendritic intraepidermal γδ T cells (DETCs), a prototypic tissue-intrinsic, innate-like T-cell compartment that reportedly regulates ACD, but by no elucidated mechanism. RESULTS: In addition to eliciting CD8 TRM, ACD induced DETC activation and an intimate coregulatory association of the 2 cell types. This depended on DETC sensing IFN-γ produced by CD8 cells and involved programmed death-ligand 1 (PD-L1). Thus, in mice lacking DETC or lacking IFN-γ receptor solely on γδ cells, ACD-elicited CD8 T cells showed enhanced proliferative and effector potentials and reduced motility, collectively associated with exaggerated ACD pathology. Comparable dysregulation was elicited by PD-L1 blockade in vitro, and IFN-γ-regulated PD-L1 expression was a trait of human skin-homing and intraepithelial γδ T cells. CONCLUSIONS: The size and quality of the tissue-infiltrating CD8 T-cell response during ACD can be profoundly regulated by local innate-like T cells responding to IFN-γ and involving PD-L1. Thus, interindividual and tissue-specific variations in tissue-intrinsic lymphocytes may influence responses to allergens and other challenges and may underpin inflammatory pathologies such as those repeatedly observed in γδ T-cell-deficient settings.

Genetic Landscape of Factor VII Deficiency: Insights from a Comprehensive Analysis of Pathogenic Variants and Their Impact on Coagulation Activity.

Congenital factor VII (FVII) deficiency is a rare genetic bleeding disorder characterized by deficient or reduced activity of coagulation FVII. It is caused by genetic variants in the F7 gene. We aimed to evaluate the rate of detection of pathogenic variants in the F7 gene in a large group of patients with FVII deficiency and investigate the correlations between the F7 genotype and FVII activity (FVII:C). Moreover, the influence of the common genetic variant rs6046: c.1238G>A; p.(Arg413Gln), designated as the M2 allele, on FVII:C was investigated. Genetic analysis of the F7 gene was performed on 704 index patients (IPs) using either direct Sanger- or next-generation sequencing. Genetic variants were detected in 390 IPs, yielding a variant detection rate (VDR) of 55%. Notably, the VDR exhibited a linear decline with increasing FVII:C levels. We identified 124 genetic variants, of which 48 were not previously reported. Overall, the frequency of the M2 allele was considerably higher in patients with mild deficiency (FVII:C > 20 IU/dl). Furthermore, IPs lacking an identified pathogenic variant exhibited a significantly higher prevalence of the M2 allele (69%) compared to IPs with a disease-causing variant (47%). These results strongly support the association of the M2 allele with decreased FVII:C levels. This study shows the utility of FVII:C as a predictive marker for identifying pathogenic variants in patients with FVII deficiency. The M2 allele contributes to the reduction of FVII:C levels, particularly in cases of mild deficiency.

Complexes and Supramolecular Associates of Dodecyl-Containing Oligonucleotides with Serum Albumin.

Serum albumin is currently in the focus of biomedical research as a promising platform for the creation of multicomponent self-assembling systems due to the presence of several sites with high binding affinity of various compounds in its molecule, including lipophilic oligonucleotide conjugates. In this work, we investigated the stoichiometry of the dodecyl-containing oligonucleotides binding to bovine and human serum albumins using an electrophoretic mobility shift assay. The results indicate the formation of the albumin-oligonucleotide complexes with a stoichiometry of about 1 : (1.25 ± 0.25) under physiological-like conditions. Using atomic force microscopy, it was found that the interaction of human serum albumin with the duplex of complementary dodecyl-containing oligonucleotides resulted in the formation of circular associates with a diameter of 165.5 ± 94.3 nm and 28.9 ± 16.9 nm in height, and interaction with polydeoxyadenylic acid and dodecyl-containing oligothymidylate resulted in formation of supramolecular associates with the size of about 315.4 ± 70.9 and 188.3 ± 43.7 nm, respectively. The obtained data allow considering the dodecyl-containing oligonucleotides and albumin as potential components of the designed self-assembling systems for solving problems of molecular biology, biomedicine, and development of unique theranostics with targeted action.

Benign and malignant prostate neoplasms show different spatial organization of collagen.

AIM: To compare the indicators of the spatial organization of collagen and its regulating factors between benign and malignant prostate neoplasms. METHODS: The study involved tumor tissue samples from 40 patients with stage II-III prostate cancer (PCa) and 20 patients with benign prostatic hyperplasia (BPH). The localization of collagen was determined with a Masson trichrome stain. To establish quantitative indicators of the spatial organization of collagen, morphometric studies were carried out with the CurveAlign and ImageJ programs. RESULTS: PCa tissue had two times lower collagen density (P<0.0001) and 1.3 times lower levels of collagen alignment (P=0.018) compared with BPH tissue. In PCa tissue, collagen fibers were shorter (by 24.2%; P<0.001) and thicker (by 15.5%; P<0.001). PCa tissue samples showed significantly higher levels of metalloproteinase (MMP)-2 (by 2.4 times; P=0.001), MMP-8 (by 2.3 times; P=0.007), and MMP-13 (by 1.9 times; P=0.004). CONCLUSIONS: Collagen matrix spatial organization features, as well as its regulatory factors, could be potential biomarkers of malignant prostate neoplasms.

Candidate Genes for IgA Nephropathy in Pediatric Patients: Exome-Wide Association Study.

IgA nephropathy (IgAN) is an autoimmune disorder which is believed to be non-monogenic. We performed an exome-wide association study of 70 children with IgAN and 637 healthy donors. The HLA allele frequencies were compared between the patients and healthy donors from the bone marrow registry of the Pirogov University. We tested 78,020 gene markers for association and performed functional enrichment analysis and transcription factor binding preference detection. We identified 333 genetic variants, employing three inheritance models. The most significant association with the disorder was observed for rs143409664 (PRAG1) in the case of the additive and dominant models (PBONF = 1.808 × 10-15 and PBONF = 1.654 × 10-15, respectively), and for rs13028230 (UBR3) in the case of the recessive model (PBONF = 1.545 × 10-9). Enrichment analysis indicated the strongly overrepresented "immune system" and "kidney development" terms. The HLA-DQA1*01:01:01G allele (p = 0.0076; OR, 2.021 [95% CI, 1.322-3.048]) was significantly the most frequent among IgAN patients. Here, we characterized, for the first time, the genetic background of Russian IgAN patients, identifying the risk alleles typical of the population. The most important signals were detected in previously undescribed loci.

Resolving the Hydride Transfer Pathway in Oxidative Conversion of Proline to Pyrrole.

Thiotemplated pyrrole is a prevailing intermediate in the synthesis of numerous natural products in which the pyrrole is tethered to a carrier protein (CP). Biosynthesis of the pyrrole requires oxidation of an l-proline side chain. Herein, we investigate the biocatalytic mechanism of proline-to-pyrrole synthesis by molecular dynamics simulations, quantum mechanics/molecular mechanics simulations, and electronic structure calculations using the recently reported (Thapa, H. R., et al. Biochemistry 2019, 58, 918) structure of a type II nonribosomal protein synthetase (NRPS) Bmp3-Bmp1 (Oxidase-CP) complex. The substrate (l-proline) is attached to the Bmp1(CP), and the catalytic site is located inside the flavin-dependent oxidase (Bmp3). We show that the FAD isoalloxazine ring is stabilized in the catalytic site of Bmp3 by strong hydrogen bonding with Asn123, Ile125, Ser126, and Thr158. After the initial deprotonation followed by an enamine-imine tautomerization, oxidation of the C2-C3 or C2-N1 bond, through a hydride transfer (from either C3 or N1), is required for the pyrrole synthesis. Computational results indicate that the hydride transfer is more likely to occur from C3 than N1. Additionally, we demonstrate the elasticity in the oxidase active site through enzymatic synthesis of proline derivatives.

Performance comparison of Agilent new SureSelect All Exon v8 probes with v7 probes for exome sequencing.

Exome sequencing is becoming a routine in health care, because it increases the chance of pinpointing the genetic cause of an individual patient's condition and thus making an accurate diagnosis. It is important for facilities providing genetic services to keep track of changes in the technology of exome capture in order to maximize throughput while reducing cost per sample. In this study, we focused on comparing the newly released exome probe set Agilent SureSelect Human All Exon v8 and the previous probe set v7. In preparation for higher throughput of exome sequencing using the DNBSEQ-G400, we evaluated target design, coverage statistics, and variants across these two different exome capture products. Although the target size of the v8 design has not changed much compared to the v7 design (35.24 Mb vs 35.8 Mb), the v8 probe design allows you to call more of SNVs (+ 3.06%) and indels (+ 8.49%) with the same number of raw reads per sample on the common target regions (34.84 Mb). Our results suggest that the new Agilent v8 probe set for exome sequencing yields better data quality than the current Agilent v7 set.

De novo TP53 germline activating mutations in two patients with the phenotype mimicking Diamond-Blackfan anemia.

Diamond-Blackfan anemia (DBA) is an inherited bone marrow failure syndrome, associated with mutations in ribosomal protein (RP) genes. Growing data on mutations in non-RP genes in patients with DBA-like phenotype became available over recent years. We describe two patients with the phenotype of DBA (onset of macrocytic anemia within the first year of life, paucity of erythroid precursors in bone marrow) and germline de novo variants in the TP53 gene. Both patients became transfusion independent, probably due to L-leucine therapy. The possible role of TP53 variants should be considered in patients with DBA-like phenotype and no mutations in RP genes.

Joint neutron/molecular dynamics vibrational spectroscopy reveals softening of HIV-1 protease upon binding of a tight inhibitor.

Biomacromolecules are inherently dynamic, and their dynamics are interwoven into function. The fast collective vibrational dynamics in proteins occurs in the low picosecond timescale corresponding to frequencies of ∼5-50 cm-1. This sub-to-low THz frequency regime covers the low-amplitude collective breathing motions of a whole protein and vibrations of the constituent secondary structure elements, such as α-helices, ß-sheets and loops. We have used inelastic neutron scattering experiments in combination with molecular dynamics simulations to demonstrate the vibrational dynamics softening of HIV-1 protease, a target of HIV/AIDS antivirals, upon binding of a tight clinical inhibitor darunavir. Changes in the vibrational density of states of matching structural elements in the two monomers of the homodimeric protein are not identical, indicating asymmetric effects of darunavir on the vibrational dynamics. Three of the 11 major secondary structure elements contribute over 40% to the overall changes in the vibrational density of states upon darunavir binding. Molecular dynamics simulations informed by experiments allowed us to estimate that the altered vibrational dynamics of the protease would contribute -3.6 kcal mol-1 at 300 K, or 25%, to the free energy of darunavir binding. As HIV-1 protease drug resistance remains a concern, our results open a new avenue to help establish a direct quantitative link between protein vibrational dynamics and drug resistance.

The aorto-left ventricular tunnel from a fetal perspective: Original case series and literature review.

INTRODUCTION: Aorto-left ventricular tunnel (ALVT) accounts for <0.1% of congenital heart defects. Evidence on the prognosis from a fetal perspective is limited. With this retrospective international case series, we provide information on the outcome of fetuses with ALVT. METHODS: All members of the Association for European Pediatric and Congenital Cardiology's (AEPC) fetal working group and fetal medicine units worldwide were invited for participation. We observed antenatal parameters, neonatal outcome and postnatal follow-up. Additionally, a systematic search of the literature was performed. RESULTS: Twenty fetuses with ALVT were identified in 10 participating centers (2001-2019). Fetal echocardiographic characteristics of ALVT included an increased cardiac-thorax ratio (95%), left ventricular end-diastolic diameter (90%) and a dysplastic aortic valve (90%). Extracardiac malformations were rare (5%). Eight fetuses died at a median gestational age (GA) of 21 + 6 weeks (range, 19-24): all showed signs of hydrops prior to 24 weeks or at autopsy. All others (60%, 12/2) were live-born (median GA 38 + 4, range 37-40), underwent surgery and were alive at last follow up (median 3.2 years, range 0.1-17). The literature reported 22 ALVT fetuses with similar outcome. CONCLUSIONS: In the absence of fetal hydrops, ALVT carries a good prognosis. Fetuses who survive to 24 weeks without hydrops are likely to have a good outcome.

Functional Characterization of Antithrombin Mutations by Monitoring of Thrombin Inhibition Kinetics.

Inactivation of thrombin by the endogenous inhibitor antithrombin (AT) is a central mechanism in the regulation of hemostasis. This makes hereditary AT deficiency, which is caused by SERPINC1 gene mutations, a major thrombophilic risk factor. Aim of this study was to assess to what extent AT mutations impair thrombin inhibition kinetics. The study population included 36 thrombophilic patients with 19 different mutations and mean AT levels of 65% in a thrombin-based functional assay, and 26 healthy controls. To assess thrombin inhibition kinetics, thrombin (3.94 mU/mL final concentration) was added to citrated plasma. Subsequently, endogenous thrombin inhibition was stopped by addition of the reversible thrombin inhibitor argatroban and the amount of argatroban-complexed thrombin quantified using an oligonucleotide-based enzyme capture assay. The plasma half-life of human thrombin was significantly longer in patients with AT mutations than in the controls (119.9 versus 55.9 s). Moreover, it was disproportionately prolonged when compared with preparations of wild type AT in plasma, in whom a comparable thrombin half-life of 120.8 s was reached at a distinctly lower AT level of 20%. These findings may help to better understand the increased thrombotic risk of SERPINC1 mutations with near normal AT plasma levels in functional assays.

An Influence of Modification with Phosphoryl Guanidine Combined with a 2'-O-Methyl or 2'-Fluoro Group on the Small-Interfering-RNA Effect.

Small interfering RNA (siRNA) is the most important tool for the manipulation of mRNA expression and needs protection from intracellular nucleases when delivered into the cell. In this work, we examined the effects of siRNA modification with the phosphoryl guanidine (PG) group, which, as shown earlier, makes oligodeoxynucleotides resistant to snake venom phosphodiesterase. We obtained a set of siRNAs containing combined modifications PG/2'-O-methyl (2'-OMe) or PG/2'-fluoro (2'-F); biophysical and biochemical properties were characterized for each duplex. We used the UV-melting approach to estimate the thermostability of the duplexes and RNAse A degradation assays to determine their stability. The ability to induce silencing was tested in cultured cells stably expressing green fluorescent protein. The introduction of the PG group as a rule decreased the thermodynamic stability of siRNA. At the same time, the siRNAs carrying PG groups showed increased resistance to RNase A. A gene silencing experiment indicated that the PG-modified siRNA retained its activity if the modifications were introduced into the passenger strand.

Synergistic Biophysical Techniques Reveal Structural Mechanisms of Engineered Cationic Antimicrobial Peptides in Lipid Model Membranes.

In the quest for new antibiotics, two novel engineered cationic antimicrobial peptides (eCAPs) have been rationally designed. WLBU2 and D8 (all 8 valines are the d-enantiomer) efficiently kill both Gram-negative and -positive bacteria, but WLBU2 is toxic and D8 nontoxic to eukaryotic cells. We explore protein secondary structure, location of peptides in six lipid model membranes, changes in membrane structure and pore evidence. We suggest that protein secondary structure is not a critical determinant of bactericidal activity, but that membrane thinning and dual location of WLBU2 and D8 in the membrane headgroup and hydrocarbon region may be important. While neither peptide thins the Gram-negative lipopolysaccharide outer membrane model, both locate deep into its hydrocarbon region where they are primed for self-promoted uptake into the periplasm. The partially α-helical secondary structure of WLBU2 in a red blood cell (RBC) membrane model containing 50 % cholesterol, could play a role in destabilizing this RBC membrane model causing pore formation that is not observed with the D8 random coil, which correlates with RBC hemolysis caused by WLBU2 but not by D8.

Parameterization of a drug molecule with a halogen σ-hole particle using ffTK: Implementation, testing, and comparison.

Halogen atoms are widely used in drug molecules to improve their binding affinity for the receptor proteins. Many of the examples involve "halogen bonding" between the molecule and the binding site, which is a directional interaction between a halogen atom and a nucleophilic atom. Such an interaction is induced by an electron cloud shift of the halogen atom toward its covalently bonded neighbor to form the σ-bond, leaving a small electrostatic positive region opposite to the bond called the "σ-hole." To mimic the effect of the σ-hole in the CHARMM non-polarizable force field, recently CGenFF added a positively charged massless particle to halogen atoms, positioned at the opposite side of the carbon-halogen bond. This particle is referred to as a lone pair (LP) particle because it uses the lone pair implementation in the CHARMM force field. Here, we have added support for LP particles to ffTK, an automated force field parameterization toolkit widely distributed as a plugin to the molecular visualization software VMD. We demonstrate the updated optimization process using an example halogenated drug molecule, AT130, which is a capsid assembly modulator targeting the hepatitis B virus. Our results indicate that parameterization with the LP particle significantly improves the accuracy of the electrostatic response of the molecule, especially around the halogen atom. Although the inclusion of the LP particle does not produce a prominent effect on the interactions between the molecule and its target protein, the protein-ligand binding performance is greatly improved by optimization of the parameters.

Effortful verb retrieval from semantic memory drives beta suppression in mesial frontal regions involved in action initiation.

The contribution of the motor cortex to the semantic retrieval of verbs remains a subject of debate in neuroscience. Here, we examined whether additional engagement of the cortical motor system was required when access to verbs semantics was hindered during a verb generation task. We asked participants to produce verbs related to presented noun cues that were either strongly associated with a single verb to prompt fast and effortless verb retrieval, or were weakly associated with multiple verbs and more difficult to respond to. Using power suppression of magnetoencephalography beta oscillations (15-30 Hz) as an index of cortical activation, we performed a whole-brain analysis in order to identify the cortical regions sensitive to the difficulty of verb semantic retrieval. Highly reliable suppression of beta oscillations occurred 250 ms after the noun cue presentation and was sustained until the onset of verbal response. This was localized to multiple cortical regions, mainly in the temporal and frontal lobes of the left hemisphere. Crucially, the only cortical regions where beta suppression was sensitive to the task difficulty, were the higher order motor areas on the medial and lateral surfaces of the frontal lobe. Stronger activation of the premotor cortex and supplementary motor area accompanied the effortful verb retrieval and preceded the preparation of verbal responses for more than 500 ms, thus, overlapping with the time window of verb retrieval from semantic memory. Our results suggest that reactivation of verb-related motor plans in higher order motor circuitry promotes the semantic retrieval of target verbs.

Characterization of the mutation spectrum in a Pakistani cohort of type 3 von Willebrand disease.

INTRODUCTION: Type 3 von Willebrand disease (VWD), a severe autosomal recessive hereditary bleeding disorder, is described by the virtual absence of von Willebrand factor (VWF). In consanguineous populations, for example Pakistan, the disease is reported with a higher incidence rate than the worldwide prevalence. AIMS: This study aims to characterize molecular pathology and clinical profile of type 3 VWD cohort of Pakistani origin. METHODS: In total, 48 patients were enrolled in the current study. Initially, the index patients (IPs) were evaluated by a standardized questionnaire for recording bleeding manifestations and by performing conventional coagulation tests. The diagnosis of VWD type 3 was confirmed by VWF antigens less than 5 IU/dL. Direct sequencing of VWF gene (VWF) was carried out to identify causative gene variations. We evaluated the potential consequence of novel splice site and missense variations by predictive computational programs and in silico structural analysis. RESULTS: VWF mutations were detected in 46 out of 48 IPs (95.8%), predominantly as homozygous variants. In total, twenty-nine different gene defects were characterized in this cohort from which 10 (34.5%) are novel. The majority of the mutations were null alleles (66%; including gene conversions, nonsense, splice site variations, small deletions and insertions), and 34% of them were missense substitutions. CONCLUSION: Herein, we reported for the first time, the pattern of gene defects in Pakistani type 3 VWD cohort. We identified a wide heterogeneous mutation spectrum along with variability in the type of bleeding episodes.

Protein structural and surface water rearrangement constitute major events in the earliest aggregation stages of tau.

Protein aggregation plays a critical role in the pathogenesis of neurodegenerative diseases, and the mechanism of its progression is poorly understood. Here, we examine the structural and dynamic characteristics of transiently evolving protein aggregates under ambient conditions by directly probing protein surface water diffusivity, local protein segment dynamics, and interprotein packing as a function of aggregation time, along the third repeat domain and C terminus of Δtau187 spanning residues 255-441 of the longest isoform of human tau. These measurements were achieved with a set of highly sensitive magnetic resonance tools that rely on site-specific electron spin labeling of Δtau187. Within minutes of initiated aggregation, the majority of Δtau187 that is initially homogeneously hydrated undergoes structural transformations to form partially structured aggregation intermediates. This is reflected in the dispersion of surface water dynamics that is distinct around the third repeat domain, found to be embedded in an intertau interface, from that of the solvent-exposed C terminus. Over the course of hours and in a rate-limiting process, a majority of these aggregation intermediates proceed to convert into stable ß-sheet structured species and maintain their stacking order without exchanging their subunits. The population of ß-sheet structured species is >5% within 5 min of aggregation and gradually grows to 50-70% within the early stages of fibril formation, while they mostly anneal block-wisely to form elongated fibrils. Our findings suggest that the formation of dynamic aggregation intermediates constitutes a major event occurring in the earliest stages of tau aggregation that precedes, and likely facilitates, fibril formation and growth.

Targeting Bacillus cereus cells: increasing efficiency of antimicrobials by the bornylpossessing 2(5Н)-furanone derivative.

Among a variety of antimicrobial compounds, the derivatives of 2(5H)-furanone exhibit different effects on Firmicutes and Proteobacteria. While inhibiting quorum-dependent biofilm formation and virulence factor expression by Gram-negative bacteria through specific interference with the AI-2 signaling pathways, these compounds demonstrate bactericidal effects against Gram-positive bacteria. Here we report that 3,4-dichloro-5(S)-[(1S,2R,4S)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-yloxy]-2(5H)-furanone designed as F123 inhibits growth and biofilm formation by the food-poisoning bacterium Bacillus cereus at 8 µg/ ml and kills bacteria at 16 µg/ml. While the growth of Staphylococcus aureus, Staphylococcus epidermidis, Micrococcus luteus, Bacillus subtilis were also inhibited at 8-16 µg/ml of F123, no bactericidal effect on these strains was observed at concentrations up to 128 µg/ml, suggesting pronounced specificity of F123 for B. cereus. In a checker-board assay F123 increased the efficacy of amikacin, gentamicin and benzalkonium chloride against B. cereus with medians of fractional inhibitory concentration index of 0.38, 0.56 and 0.56, respectively. Moreover, the number of viable B. cereus cells in biofilm was reduced by more than 3 orders of magnitude at 64 µg/ml of F123, suggesting its chemotype as a promising enhancer for specific treatment of B. cereus-associated topical infections, including biofilm-embedded bacteria.