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Ribosomally synthesized and post-translationally modified peptides (RiPPs) are natural products with remarkable chemical and functional diversities. These peptides are often synthesized as signals or antibiotics and frequently associated with quorum sensing (QS) systems. With the increasing number of available genomes, many hitherto unseen RiPP biosynthetic pathways have been mined, providing new resources for novel bioactive compounds. Herein, we investigated the underexplored biosynthetic potential of Streptococci, prevalent bacteria in mammal–microbiomes that include pathogenic, mutualistic, and commensal members. Using the transcription factor-centric genome mining strategy, we discovered a new family of lanthipeptide biosynthetic loci under the control of potential QS. By in vitrostudies, we investigated the reaction of one of these lanthipeptide synthetases and found that it installs only one lanthionine moiety onto its short precursor peptide by connecting a conserved TxxC region. Bioinformatics and in vitrostudies revealed that these lanthipeptide synthetases (class VI) are novel lanthipeptide synthetases with a truncated lyase, a kinase, and a truncated cyclase domain. Our data provide important insights into the processing and evolution of lanthipeptide synthetase to tailor smaller substrates. The data are important for obtaining a mechanistic understanding of the post-translational biosynthesis machinery of the growing variety of lanthipeptides.

This study investigates whether directors who are former CEOs have an impact on corporate cash holdings. We find that such directors are negatively related to corporate cash holdings because they play an effective monitoring role in reducing cash holdings caused by agency problems. Our results remained robust even after several robustness tests. This negative correlation between former CEO directors and cash holdings is more significant in non-state-owned companies and companies with less fierce product market competition, while the monitoring effect is more effective when the agency conflict between management and shareholders and agency conflict between the largest shareholder and minority shareholders is more serious. We also show evidence that former CEO directors could play an effective monitoring role irrespective of their position on the board.

COVID‐19 is currently pandemic and the detection of SARS‐CoV‐2 variants in wastewater is causing widespread concern. Herein, cold atmospheric plasma (CAP) is proposed as a novel wastewater disinfection technology that effectively inactivates SARS‐CoV‐2 transcription‐ and replication‐competent virus‐like particles, coronavirus GX_P2V, pseudotyped SARS‐CoV‐2 variants, and porcine epidemic diarrhoea virus in a large volume of water within 180 s (inhibition rate > 99%). Further, CAP disinfection did not adversely affect the viability of various human cell lines. It is identified that CAP produced peroxynitrite (ONOO−), ozone (O3), superoxide anion radicals (O2−), and hydrogen peroxide (H2O2) as the major active substances for coronavirus disinfection. Investigation of the mechanism showed that active substances not only reacted with the coronavirus spike protein and affected its infectivity, but also destroyed the nucleocapsid protein and genome, thus affecting virus replication. This method provides an efficient and environmentally friendly strategy for the elimination of SARS‐CoV‐2 and other coronaviruses from wastewater. Cold atmospheric plasma can produce peroxynitrite (ONOO−), ozone (O3), superoxide anion radicals (O2−), and hydrogen peroxide (H2O2) as the major reactive species to inactivate coronaviruses by disrupting the viral Spike protein and genomic RNA, thus hindering viral entry and replication. This study highlights the potential of cold atmospheric plasma as a promising approach to combat coronavirus infections.

Canine parvovirus 2 (CPV-2) and feline panleukopenia virus (FPLV) often cause acute enteric disease in their hosts. A simple, rapid, and effective method for the on-site detection of these viruses would be useful. We used a denaturation bubble-mediated strand exchange amplification (SEA) method to successfully detect CPV-2 and FPLV in fecal samples. SEA could detect as little as 3.6 pg/μL of CPV-2 and 6.6 pg/μL of FPLV genomic DNA following a 40-min incubation at an isothermal temperature of 61°C. Unlike PCR, SEA does not require complicated equipment, and positive samples produce a color change that can be visualized by the naked eye. Additionally, SEA is simpler than PCR because no extraction is needed, and heating of the fecal sample at 98°C can be performed with a heating block or water bath. This rapid and effective nucleic acid detection platform could be used as a point-of-care test for the detection of CPV-2 and FPLV.

Salmonellais regarded as the predominant cause of foodborne illnesses worldwide, and the increase of these antimicrobial-resistant strains makes it more difficult to prevent. On this occasion, bacteriophages (phages) stand out as an alternative biocontrol agent with high efficiency and low mutation rates. Salmonellaphages have confronted challenges to counteract with more than 2,500 serovars of Salmonellaspp. and overcome the universality of antibiotics to different species, and thus, broad-host-range phages infecting Salmonellaspp. are urgently required to realize precise poultry treatment or clinical therapy. First, phage STP4-a was screened to have a broad host range through bioinformatics analysis, and then the host range assay proved that phage STP4-a could inhibit 88 out of 91 Salmonellastrains. Then, in silico analysis excluded the possibility of phage STP4-a possessing any known lysogeny factors, toxins, pathogen-related genes, or foodborne allergens, and oral toxicity studies further ensured the safety of unknown factors or suspected risks. In addition, strong inhibition effects of phage STP4-a were seen on both single Salmonellastrain and multiple Salmonellastrains in vitro, reducing 3-5 log in 30 min. Phage STP4-a could survive and keep more than 50% activity in simulated stomach or intestine environments in vitro. In terms of antimicrobial activities in chickens, pretreatment with phage STP4-a was the most efficient approach to Salmonellabiocontrol, non-detectable in feces during the 14-day experimental period. Therefore, phage STP4-a was an extremely broad-host-range and safe biocontrol agent, performing its potential as a food additive or therapeutic drug in poultry industry.

Thermal resistance of desiccation-adapted SalmonellaSenftenberg 775W was compared with that of Enterococcus faeciumNRRL B-2354 in aged broiler litter. Aged broiler litter with 20, 30, and 40% moisture contents was inoculated separately with desiccation-adapted SalmonellaSenftenberg 775W and E. faeciumNRRL B-2354 at ca. 5 to 6 log CFU/g and then heat treated at 75, 85, and 150°C. At all tested temperatures, desiccation-adapted E. faeciumNRRL B-2354 was more heat resistant than desiccation-adapted SalmonellaSenftenberg 775W (P <0.05). During the treatments at 75 and 85°C, E. faeciumNRRL B-2354 in aged broiler litter with all moisture contents was reduced by 2.89 to 4.12 log and was above the detection limit of direct plating (1.30 log CFU/g), whereas SalmonellaSenftenberg 775W could not be detected by enrichment (>5-log reduction) during holding time at these temperatures. At 150°C, E. faeciumNRRL B-2354 in aged broiler litter with 20 and 30% moisture contents was still detectable by enrichment after heat exposure for up to 15 min, whereas SalmonellaSenftenberg 775W in aged broiler litter with all moisture contents could not be detected throughout the entire treatment. Our results revealed that E. faeciumNRRL B-2354 can be used as a surrogate for Salmonellato validate the thermal processing of poultry litter by providing a sufficient safety margin. This study provides a practical tool for poultry litter processors to evaluate the effectiveness of their thermal processing.

Vibrio parahaemolyticusis an important foodborne pathogen that is generally transmitted via raw or undercooked seafood. Endolysins originating from bacteriophages offer a new way to control bacterial pathogens. The objectives of this study were to sequence a novel lytic V. parahaemolyticusphage VPp1 and determine the antibacterial activities of the recombinant endolysin (LysVPp1) derived from this phage. The complete VPp1 genome contained a double-stranded DNA of 50,431 bp with a total G+C content of 41.35%. The genome was predicted to encode 67 open reading frames (ORFs), which were organized as nucleotide metabolism, replication, structure, packaging, lysis, and some additional functions. Two tRNAs were encoded to carry anticodons UGG and CCA. Among the functional proteins, ORF33 was deduced to encode endolysin, whereas no holin/antiholin or Rz/Rz1 lysis gene equivalents were found in the VPp1 genome. ORF33 was cloned and expressed. The endolysin LysVPp1 could lyse 9 of 12 V. parahaemolyticusstrains, showing its relatively broader host spectrum than phage VPp1, which lysed only 3 of 12 V. parahaemolyticusstrains. Furthermore, for EDTA-pretreated bacterial cells, the optical density of the LysVPp1 treatment group decreased by 0.4 at 450 nm, compared with less than 0.1 in control groups, demonstrating enhanced hydrolytic properties. These results contribute to the potential for development of novel enzybiotics for controlling V. parahaemolyticus.

Although Shewanella putrefaciensis the specific spoilage organism in most seafood, only seven Shewanellaphages have been sequenced and their endolysins have not been reported until now. In this study, we cloned and expressed two lysis-related proteins (Spp64 and Spp62) encoded by phage Spp001, the first sequenced S. putrefaciensphage. Both recombinant proteins showed strong lytic capability toward chilled S. putrefaciensSp225 and presented a wider activity spectrum compared with bacteriophage Spp001. The enzymatic activity of crude Spp64, Spp62ΔTD, and Spp62ΔTD-GST can cause decreases of 0.691, 0.674, and 0.685, respectively, as tested through the turbidity reduction assay. Furthermore, purified enzyme Spp64 at concentrations of 537.5 and 4.20 μg/mL was enough to decrease the optical density of chilled S. putrefaciensby 0.881 and 0.492, respectively, within 15 min. The recombinant Spp64 has a peptidase catalytic domain and exhibits high temperature resistance. Moreover, Spp64 displayed superior enzymatic activity in a range of pH values that matches environmental conditions (pH between 5.0 and 10.0), which demonstrates that its application in seafood is feasible. The present work is to our knowledge the first report on lysis-related enzymes encoded in the Shewanellaphage. Both proteins presented extraordinary potential to control S. putrefaciens; we hope that these proteins can be developed as novel antibacterial agents in further research.

Multitarget HDAC inhibitors capable of simultaneously blocking the BRD4-LIFR-JAK1-STAT3 signaling pathway hold great potential for the treatment of TNBC and other solid tumors. Herein, novel Fedratinib-based multitarget HDAC inhibitors were rationally designed, synthesized, and biologically evaluated, among which compound 25apstood out as a potent HDAC/JAK/BRD4 triple inhibitor. Satisfyingly, compound 25apled to concurrent inhibition of HDACs and the BRD4-LIFR-JAK1-STAT3 signaling pathway, which was validated by hyper-acetylation of histone and α-tubulin, hypo-phosphorylation of STAT3, downregulation of LIFR, MCL-1, and c-Myc in MDA-MB-231 cells. The multitarget effects of 25apcontributed to its robust antitumor response, including potent antiproliferative activity, remarkable apoptosis-inducing activity, and inhibition of colony formation. Notably, 25appossessed an acceptable therapeutic window between normal and cancerous cells, desirable in vitro metabolic stability in mouse microsome, and sufficient in vivo exposure via intraperitoneal administration. Additionally, the in vivo antitumor potency of 25apwas demonstrated in an MDA-MB-231 xenograft model.

Investigating immune memory to vaccinia virus and pre-existing immunity to monkeypox virus (MPXV) among the population is crucial for the global response to this ongoing monkeypox (MPOX) epidemic. Blood was sampled from vaccinees inoculated with vaccinia virus Tiantan strain (VTT) born before 1981 and unvaccinated controls born since 1982. After at least 40 years of the inoculation, 60% or 5% of VTT vaccinees possess neutralizing antibodies (NAbs) to VTT or MPXV, with at least 50% having T cell memory to VTT protein antigens. Notably, 46.7% of vaccinees show pre-existing T cell responses to MPXV. Broad pre-existing CD8+T cell reactivities to MPXV are detected not only against conserved epitopes but also against variant epitopes between VTT and MPXV. Persistent NAbs and T cell memory to VTT among vaccinees, along with pre-existing T cells to MPXV among both vaccinees and the unvaccinated population, indicate a particular immune barrier to MPOX.