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The food-borne bacterial gastrointestinal infection is a serious public health threat. Defensins are evolutionarily conserved innate immune components with broad-spectrum antibacterial activity that do not easily induce resistance. AvBD103b, an avian defensin with potent activity against Salmonella enteritidis, was isolated from the stomach contents of the king penguin ( Aptenodytes patagonicus). To elucidate further the antibacterial mechanism of AvBD103b, its effect on the S. enteritidis CVCC3377 cell membrane and intracellular DNA was researched. The cell surface hydrophobicity and a N-phenyl-1-naphthylamine uptake assay demonstrated that AvBD103b treatment increased the cell surface hydrophobicity and outer membrane permeability. Atomic absorption spectrometry, ultraviolet spectrophotometry, flow cytometry, and transmission electron microscopy (TEM) indicated that AvBD103b treatment can lead to the release of the cellular contents and cell death through damage of the membrane. DNA gel retardation and circular dichroism analysis demonstrated that AvBD103b interacted with DNA and intercalated into the DNA base pairs. A cell cycle assay demonstrated that AvBD103b affected cellular functions, such as DNA synthesis. Our results confirmed that AvBD103b exerts its antibacterial activity by damaging the cell membrane and interfering with intracellular DNA, ultimately causing cell death, and suggested that AvBD103b may be a promising candidate as an alternative to antibiotics against S. enteritidis. [ABSTRACT FROM AUTHOR]

The candidacidal mechanisms of NZ17074, which is a variant of arenicin-3 from Arenicola marina, against human pathogenic fungus Candida albicans are reported in this work. The minimum inhibitory concentration (MIC) of NZ17074 toward C. albicans was 4 μg/ml, and this peptide exerted marked candidacidal activity in an energy-dependent and salt-sensitive manner. The flow cytometric analysis using propidium iodide (PI) showed that the plasma membrane of cells treated with NZ17074 was perturbed and that the cells were arrested in the G2/M phase. The dihydrorhodamine-123 (DHR-123) staining showed that the reactive oxygen species (ROS) production of C. albicans increased after exposure to NZ17074. Typical cellular disruption events, such as mitochondrial degradation, nuclear fragmentation, nuclear membrane disruption, and chromatin condensation, were further revealed through rhodamine 123 (RH123) staining, 4′,6-diamidino-2-phenylindole (DAPI) staining, and transmission electron microscopy. In addition, the intracellular localization of this peptide was concentration dependent: it was located in the membrane at low concentrations (4 to 8 μg/ml) and penetrated into the cytoplasm at high concentrations (16 to 32 μg/ml). Our results suggested that NZ17074 exerts its candidacidal effects by disrupting the cell membrane, inducing apoptosis, and interrupting the cell cycle. These findings showed the potential of NZ17074 as a new candidacidal peptide, in addition to its antibacterial activities. [ABSTRACT FROM AUTHOR]

In wireless mesh networks, delay and reliability are two critical issues in the support of delay-sensitive applications. Due to sleep scheduling designed for energy efficiency, a node along an end-to-end path needs to wait for its next hop to wake up before it can transmit, which incurs extra delay. In addition, because of unreliable wireless communications, a node may not successfully receive the packet even when it is in active mode. In this paper, we propose a coded anycast packet forwarding (CAPF) scheme for both unicast and multicast communications such that the delay can be reduced and the reliability can be improved. We theoretically analyze the impact of nodes' awake probability and the link loss probability on the end-to-end delay and the reliability. A tradeoff between the end-to-end delay and the reliability is also investigated. Simulation results demonstrate that CAPF provides a flexible mechanism to make good delay-reliability tradeoff and is effective to reduce the end-to-end delay and enhance the reliability. [ABSTRACT FROM AUTHOR]

This study is aimed at examining the impact of ChatGPT on pediatric endocrine and metabolic conditions, particularly in the areas of screening and diagnosis, in both Chinese and English modes. A 40-question questionnaire covering the four most common pediatric endocrine and metabolic conditions was posed to ChatGPT in both Chinese and English three times each. Six pediatric endocrinologists evaluated the responses. ChatGPT performed better when responding to questions in English, with an unreliable rate of 7.5% compared to 27.5% for Chinese questions, indicating a more consistent response pattern in English. Among the reliable questions, the answers were more comprehensive and satisfactory in the English mode. We also found disparities in ChatGPT's performance when interacting with different target groups and diseases, with improved performance for questions posed by clinicians in English and better performance for questions related to diabetes and overweight/obesity in Chinese for both clinicians and patients. Language comprehension, providing incomprehensive answers, and errors in key data were the main contributors to the low scores, according to reviewer feedback. Conclusion: Despite these limitations, as ChatGPT continues to evolve and expand its network, it has significant potential as a practical and effective tool for clinical diagnosis and treatment. What is Known: • The deep learning-based large-language model ChatGPT holds great promise for improving clinical practice for both physicians and patients and has the potential to increase the speed and accuracy of disease screening and diagnosis, as well as enhance the overall efficiency of the medical process. However, the reliability and appropriateness of AI model responses in specific field remains unclear. • This study focused on the reliability and appropriateness of AI model responses to straightforward and fundamental questions related to the four most prevalent pediatric endocrine and metabolic disorders, for both healthcare providers and patients, in different language scenarios. What is New: • The AI model performed better when responding to questions in English, with more consistent, as well as more comprehensive and satisfactory responses. In addition, we also found disparities in ChatGPT's performance when interacting with different target groups and different diseases. • Despite these limitations, as ChatGPT continues to evolve and expand its network, it has significant potential as a practical and effective tool for clinical diagnosis and treatment. [ABSTRACT FROM AUTHOR]

Many different encoding algorithms for systematic polar codes (SPC) have been introduced since SPC was proposed in 2011. However, the number of the computing units of exclusive OR (XOR) has not been optimized yet. According to an iterative property of the generator matrix and particular lower triangular structure of the matrix, we propose an optimized encoding algorithm (OEA) of SPC that can reduce the number of XOR computing units compared with existing non-recursive algorithms. We also prove that this property of the generator matrix could extend to different code lengths and rates of the polar codes. Through the matrix segmentation and transformation, we obtain a submatrix with all zero elements to save computation resources. The proportion of zero elements in the matrix can reach up to 58.5% from the OEA for SPC when the code length and code rate are 2048 and 0.5, respectively. Furthermore, the proposed OEA is beneficial to hardware implementation compared with the existing recursive algorithms in which signals are transmitted bidirectionally. [ABSTRACT FROM AUTHOR]

Obstructive Sleep Apnea (OSA) is related to repeated upper airway collapse, intermittent hypoxia, and intestinal barrier dysfunction. The resulting damage to the intestinal barrier may affect or be affected by the intestinal microbiota. A prospective case–control was used, including 48 subjects from Sleep Medicine Center of Nanfang Hospital. Sleep apnea was diagnosed by overnight polysomnography. Fecal samples and blood samples were collected from subjects to detect fecal microbiome composition (by 16S rDNA gene amplification and sequencing) and intestinal barrier biomarkers—intestinal fatty acid-binding protein (I-FABP) and D-lactic acid (D-LA) (by ELISA and colorimetry, respectively). Plasma D-LA and I-FABP were significantly elevated in patients with OSA. The severity of OSA was related to differences in the structure and composition of the fecal microbiome. Enriched Fusobacterium, Megamonas, Lachnospiraceae_UCG_006, and reduced Anaerostipes was found in patients with severe OSA. Enriched Ruminococcus_2, Lachnoclostridium, Lachnospiraceae_UCG_006, and Alloprevotella was found in patients with high intestinal barrier biomarkers. Lachnoclostridium and Lachnospiraceae_UCG_006 were the common dominant bacteria of OSA and intestinal barrier damage. Fusobacterium and Peptoclostridium was independently associated with apnea–hypopnea index (AHI). The dominant genera of severe OSA were also related to glucose, lipid, neutrophils, monocytes and BMI. Network analysis identified links between the fecal microbiome, intestinal barrier biomarkers, and AHI. The study confirms that changes in the intestinal microbiota are associated with intestinal barrier biomarkers among patients in OSA. These changes may play a pathophysiological role in the systemic inflammation and metabolic comorbidities associated with OSA, leading to multi-organ morbidity of OSA. [ABSTRACT FROM AUTHOR]

This work is the first to report the antibacterial characteristics and antibacterial mechanisms of MP1102, which is a variant of NZ2114, against pathogenic Clostridium perfringens. MP1102 exhibited strong antimicrobial activity against C. perfringens strains CVCC 61, CVCC 1163, and CVCC 2032 at a low minimal inhibitory concentration (MIC) of 0.91 μM. MP1102 showed anti- C. perfringens activity over a wide pH range of 2.0 and 10.0, high thermal stability from 20 to 80 °C, and remarkable resistance to pepsin. The fractional inhibitory concentration index (FICI) indicated an additive or synergic effect between MP1102 and bacitracin zinc, nisin, vancomycin, virginiamycin, aureomycin, and ampicillin against C. perfringens (FICI = 0.3125-1.0). To further elucidate the antibacterial mechanism of MP1102, its effect on the C. perfringens CVCC 61 cell membrane and intracellular DNA was studied. Flow cytometry and scanning electron microscopy (SEM) indicated that MP1102 treatment resulted in the release of cellular contents by damaging the membrane. A DNA gel retardation and circular dichroism analysis demonstrated that MP1102 interacted with DNA and intercalated into the DNA base pairs. A cell cycle assay demonstrated that MP1102 affected cellular functions, such as DNA synthesis. These results suggested that MP1102 exhibited potential as a new antimicrobial agent against C. perfringens infections. [ABSTRACT FROM AUTHOR]

Colibacillosis, caused by pathogenic Escherichia coli, is a common disease in animals and human worldwide with extensive losses in breeding industry and with millions of people death annually. There is thus an urgent need for the development of universal vaccines against colibacillosis. In this study, the BamA protein was analyzed in silico for sequence homology, physicochemical properties, allergenic prediction, and epitopes prediction. The BamA protein (containing 286 amino acids) clusters in E. coli were retrieved in UniProtKB database, in which 81.7 % sequences were identical (Uniref entry A7ZHR7), and sequences with 94.82 % identity were above 93.4 %. Moreover, BamA was highly conserved among Salmonella and Shigella and has no allergenicity to mice and human. The epitopes of BamA were located principally in periplasm and extracellular domain. Surf_Ag_VNR domain (at position 448-810 aa) of BamA was expressed, purified, and then used for immunization of mice. Titers of the rBamA sera were 1:736,000 and 1:152,000 against rBamA and E. coli and over 1:27,000 against Salmonella and Shigella. Opsonophagocytosis result revealed that the rBamA sera strengthened the phagocytic activity of neutrophils against E. coli. The survival rate of mice vaccinated with rBamA and PBS was 80 and 20 %, respectively. These data indicated that BamA could serve as a promising universal vaccine candidate for the development of a protective subunit vaccine against bacterial infection. Thus, the above protocol would provide more feasible technical clues and choices for available control of pathogenic E. coli, Salmonella, and Shigella. [ABSTRACT FROM AUTHOR]

Currently, more antimicrobial drug candidates are urgently needed to combat the rise in drug-resistance among pathogenic microbes. A new antimicrobial peptide, MP1102, a variant of NZ2114, was designed, evaluated, and overexpressed in Pichia pastoris. The total secreted protein in cultures reached 695 mg/l, and the concentration of the recombinant MP1102 (rMP1102) was 292 mg/l. rMP1102 was purified from the fermentation supernatant by one-step cation exchange chromatography to obtain a yield of 197.1 mg/l with 96.4 % purity. rMP1102 exhibited potent activity against Gram-positive bacteria, and its minimum inhibitory concentrations (MICs) for four Staphyloccocus aureus ( S. aureus) strains ranged from 0.028 to 0.11 μM, and it had stronger activity (MIC = 0.04 to 0.23 μM) to 20 clinical isolates of MRSA (cMRSA) than rNZ2114 (MIC = 0.11 to 0.90 μM). rMP1102 was shown to kill over 99.9 % of tested S. aureus cells within 6 h when treated at one, two, and four times its MIC and over 90 % of S. aureus cells within 12 h at concentrations of 5, 10, and 20 mg/kg in a mouse thigh infection model. The higher sensitivity of MRSA to MP1102 than to its parental peptide, NZ2114, indicated by this initial pharmacodynamic analysis suggests a possible difference in the killing mechanism of these two molecules. rMP1102 caused less than 0.05 % hemolytic activity at 128 μg/ml and exhibited good thermostability from 20 to 80 °C, with its highest activity being observed at pH 8.0. These results suggest that this yeast expression system is feasible for large-scale production, and rMP1102 exerted stronger activity against S. aureus than NZ2114 via a different mechanism and exhibited potential as a new antimicrobial agent for S. aureus, especially MRSA infections. [ABSTRACT FROM AUTHOR]

With the increasing demand for resources from cloud computing users, enhancing the energy efficiency of data centers and ensuring the Quality of Service have become noteworthy research topics. Most Previous studies on Virtual Machine (VM) consolidation often neglect the delay and energy consumption associated with Power Mode Transitions (PMTs), leading to potential deviations in experimental results from real-world scenarios. In this paper, we propose a Two-Level Heuristics Virtual Machine Consolidation (TLHVMC) method that takes into account the overheads of PMTs. This method employs a Greedy Strategy-based hybrid heuristic Placement (GSP) algorithm for resource allocation. After incorporating underloaded host detection for host classification, GSP applies distinct greedy strategies on various host lists, which balances data center workload and minimizes active hosts. Moreover, Time Window-based Centralized power mode Control policies are implemented to centrally manage host power modes. These policies improve energy-saving by suspending idle hosts and reduce the Service Level Agreement violations by adaptively resuming hosts based on the data center’s state within a time window. Experimental results on real workload traces show that TLHVMC significantly improves the energy efficiency of the data center and maintains the required cloud system performance compared to some other VM consolidation algorithms. [ABSTRACT FROM AUTHOR]

Pathogenic Escherichia coli ( E. coli) is an important infectious Gram-negative bacterium causing millions of death every year. Outer membrane protein A (OmpA) has been suggested as a potential vaccine candidate for conferring protection against bacterial infection. In this study, a universal vaccine candidate for E. coli infection was developed and evaluated. Bioinformatics analysis revealed the OmpA protein from E. coli shares 96~100 %, 90~94 %, and 45 % identity with Shigella, Salmonella, and Pseudomonas strains, respectively. The ompA gene was cloned from the genomic DNA of E. coli, and then the OmpA protein was expressed in BL21 (DE3) using the auto-induction method. The recombinant OmpA (rOmpA) protein had an average molecular weight of 36 kDa with the purity of 93.5 %. Immunological analysis indicated that the titers of anti-rOmpA sera against rOmpA and whole cells were 1:642,000 and 1:140,000, respectively. Moreover, rOmpA not only conferred a high level of immunogenicity to protect mice against the challenge of E. coli, but also generated cross-protection against Shigella and Salmonella. The anti-rOmpA sera could enhance the phagocytic activity of neutrophils against E. coli. The survive ratios of mice immunized with rOmpA and PBS were 50 % and 20 % after 48 h post-challenge, indicating mice were protected from E. coli infection after immunization with rOmpA. All these results clearly indicate that rOmpA may be a promising candidate for the development of a subunit vaccine to prevent E. coli infection. [ABSTRACT FROM AUTHOR]

A novel specifically targeted antimicrobial peptide (STAMP) that was especially effective against methicillin-resistant Staphylococcus aureus (MRSA) was designed by fusing the AgrD1 pheromone to the N-terminal end of plectasin. This STAMP was named Agplectasin, and its gene was synthesized and expressed in Pichia pastoris X-33 via pPICZαA. The highest amount of total secreted protein reached 1,285.5 mg/l at 108 h during the 120-h induction. The recombinant Agplectasin (rAgP) was purified by cation exchange chromatography and hydrophobic exchange chromatography; its yield reached 150 mg/l with 94 % purity. The rAgP exhibited strong bactericidal activity against S. aureus but not Staphylococcus epidermidis or other types of tested bacteria. A bactericidal kinetics assay showed that the rAgP killed over 99.9 % of tested S. aureus (ATCC 25923 and ATCC 43300) in both Mueller-Hinton medium and human blood within 10 h when treated with 4× minimal inhibitory concentration. The rAgP caused only approximately 1 % hemolysis of human blood cells, even when the concentration reached 512 μg/ml, making it potentially feasible as a clinical injection agent. In addition, it maintained a high activity over a wide range of pH values (2.0-10.0) and demonstrated a high thermal stability at 100 °C for 1 h. These results suggested that this STAMP has the potential to eliminate MRSA strains without disrupting the normal flora. [ABSTRACT FROM AUTHOR]

To detect the soybean allergen P34 ( Gly m Bd 30K) from soybean products, the full-length cDNA sequence of P34 was synthesized and inserted into the prokaryotic expression vector pET-28a. The P34 protein was expressed in Escherichia coli BL21 (DE3) as an inclusion body under the induction of 0.8 mmol/L isopropyl β- d-1-thiogalactopyranoside. After purification with His-Bind affinity chromatography, the purity quotient of the recombinant protein was over 92 %, and its molecular weight (approximately 33 kDa) was very close to that of the native soybean P34. The polyclonal antibody (pAB) against P34 was prepared with the purified recombinant P34. The generated pAB, named as pAB-P34, exhibited high specificity to the P34 protein of the soybean meal. The indirect enzyme-linked immunosorbent assay (iELISA) based on pAB-P34 was established to determine the P34 content of soybean products. The CVs of the recovery tests of P34 were less than 7.77 %, which indicated that iELISA had high reproducibility and accuracy. Therefore, the recombinant P34 produced in the E. coli expression system, the prepared pAB-P34, and the developed iELISA could provide a valuable tool for sensitive detection of P34 in various soybean products and for future studies on allergies related to soybean P34. [ABSTRACT FROM AUTHOR]

There is an urgent need to explore new antimicrobial agents due to the looming threat of bacteria resistance. Bovine lactoferricin (LfcinB), as a multifunctional peptide, has the potential to be a new active drug in the future. In this study, it aims to investigate the effect of fatty acid conjugation on antimicrobial peptide activity and topical therapeutic efficacy in a mouse model infected with Staphylococcus hyicus. Both Lfcin4 and Lfcin5 were conjugated with the unsaturated fatty acid linoleic acid (18-C) at their N-terminus and modified by acylation at the C-terminus. The derived peptides of Lin-Lf4NH2 and Lin-Lf5NH2 showed better antibacterial activity (MICs of 3.27 to 6.64 μM) than their parent peptides (MICs of 1.83 to 59.57 μM). Lin-Lf4NH2 (63.2%, 5 min) and Lin-Lf5NH2 (35.8%, 5 min) could more rapidly penetrate bacterial membrane than Lf4NH2 (2.34%, 5 min) and Lf5NH2 (1.94%, 5 min), which further confirmed by the laser scanning confocal microscopy (LSCM). Electron microscopy observations showed Lin-Lf4NH2 and Lin-Lf5NH2 disrupted S. hyicus cell membranes and led to the leakage of contents. Furthermore, after treatment with Lin-Lf4NH2 and Lin-Lf5NH2, the abscess symptoms of mice were significantly alleviated; the recovery rate of abscesses scope of Lin-Lf4NH2 (73.25%) and Lin-Lf5NH2 (71.71%) were 38.8 and 37.9-fold higher than that of untreated group (1.89%), respectively, and superior to Lf4NH2 (46.87%) and Lf5NH2 (58.75%). They significantly reduced the bacterial load and the levels of the pro-inflammatory cytokines (TNF-α, IL-6, and IL-1β) and chemokine (MCP-1) in S. hyicus skin lesions. This study provides evidence that conjugation of a fatty acid to antimicrobial peptides can improve the activity and have potential for topical therapeutic of S. hyicus skin infections. Key points: • Lin-Lfcin4NH2/Lfcin5NH2 showed stronger antimicrobial activity than parent peptides. • Lin-Lfcin4NH2/Lfcin5NH2 had a more effective ability to destroy bacterial membranes. • Lin-Lfcin4NH2/Lfcin5NH2 showed a topically higher efficacy than parent peptides. [ABSTRACT FROM AUTHOR]

Aeromonas veronii can cause a variety of diseases such as sepsis in humans and animals. However, there has been no effective way to eradicate A. veronii. In this study, the intracellular antibacterial activities of the C-terminal aminated marine peptide N6 (N6NH2) and its D-enantiomer (DN6NH2) against A. veronii were investigated in macrophages and in mice, respectively. The result showed that DN6NH2 with the minimum inhibitory concentration (MIC) of 1.62 μM is more resistant to cathepsin B than N6NH2 (3.23 μM). The penetration percentages of the cells treated with 4–200 μg/mL fluorescein isothiocyanate (FITC)-DN6NH2 were 52.5–99.6%, higher than those of FITC-N6NH2 (27.0–99.1%). Both N6NH2 and DN6NH2 entered macrophages by macropinocytosis and an energy-dependent manner. DN6NH2 reduced intracellular A. veronii by 34.57%, superior to N6NH2 (19.52%). After treatment with 100 μg/mL DN6NH2, the levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and IL-1β were reduced by 53.45%, 58.54%, and 44.62%, respectively, lower than those of N6NH2 (15.65%, 12.88%, and 14.10%, respectively); DN6NH2 increased the IL-10 level (42.94%), higher than N6NH2 (7.67%). In the mice peritonitis model, 5 μmol/kg DN6NH2 reduced intracellular A. veronii colonization by 73.22%, which was superior to N6NH2 (32.45%) or ciprofloxacin (45.67%). This suggests that DN6NH2 may be used as the candidate for treating intracellular multidrug-resistant (MDR) A. veronii. Key points: • DN6NH2improved intracellular antibacterial activity against MDR A. veronii. • DN6NH2entered macrophages by micropinocytosis and enhanced the internalization rates. • DN6NH2effectively protected the mice from infection with A. veronii. [ABSTRACT FROM AUTHOR]

Cornelia de Lange Syndrome (CdLS) is a rare genetic disorder, which causes a range of physical, cognitive, and medical challenges. To retrospectively analyze the clinical characteristics and genetic variations of Chinese patients, and to provide experience for further diagnosis and treatment of CdLS in Chinese children, we identified 15 unrelated Chinese children who presented with unusual facial features, short stature, developmental delay, limb abnormalities, and a wide range of health conditions. In this study, targeted-next generation sequencing was used to screen for causal variants and the clinically relevant variants were subsequently verified using Sanger sequencing. DNA sequencing identified 15 genetic variations, including 11 NIPBL gene variants, two SMC1A gene variants, one RAD21 gene variant, and one HDAC8 variant. The phenotype of these patients was summarized and differences between this cohort and another four groups were compared. The clinical manifestations of the patients in this cohort were mostly consistent with other ethnicities, but several clinical features in our cohort had different frequencies compared with other groups. We identified 15 deleterious variants of which 11 were novel. Variants in the NIPBL gene were the most common cause in our cohort. Our study not only expands upon the spectrum of genetic variations in CdLS, but also broadens our understanding of the clinical features of CdLS. [ABSTRACT FROM AUTHOR]

Staphylococcus aureus is a common pathogen that can cause clinical and subclinical endometritis in humans and animals. In this study, a designed CSαβ peptide ID13 from DLP4 exhibited high stable antibacterial activity in simulated gastric fluid (90.79%), serum (99.54%), and different pH buffers (> 99%) against S. aureus CVCC 546 and lower cytotoxicity (89.62% viability) than its parent peptide DLP4 (74.14% viability) toward mouse endometrial epithelial cells (MEECs). ID13 caused a depolarization of bacterial membrane and downregulation of the expression of genes involved in membrane potential maintenance and biofilm formation. The in vitro efficacy analysis of ID13 showed a synergistic effect with vancomycin, ampicillin, rifampin, and ciprofloxacin; intracellular antimicrobial activity against S. aureus CVCC 546 in MEECs; and the ability to inhibit lipoteichoic acid-induced pro-inflammatory cytokines from RAW 264.7. In the S. aureus-induced endometritis of mice, similar to vancomycin, ID13 remarkably alleviated pathological conditions, inhibited the production of cytokines (TNF-α, IL-1ß, IL-6, and IL-10), and suppressed the TLR2-NF-κB signal pathway. Collectively, these results suggest that ID13 could be a potential candidate peptide for therapeutic application in S. aureus-induced endometritis. Key Points •Higher antibacterial activity and lower hemolysis of ID13 than DLP4. •ID13 could downregulate the genes of bacterial survival and infection. •ID13 could alleviate the S. aureus-induced endometritis of mice. •ID13 could regulate the cytokines and suppress the TLR2-NF-κB signal pathway. [ABSTRACT FROM AUTHOR]

Staphylococcus hyicus, considered as a leading pathogen of exudative epidermitis, is a serious threat to humans and animals. The emergency of bacterial resistance to antibiotics, especially in human and animal health fields, leads to an urgent need of exploration of new antimicrobial agents. In this study, NZX, a plectasin-derived peptide, was firstly expressed in Pichia pastoris X-33 and was purified by cation exchange chromatography, followed by detection of its antibacterial activity in vitro and in vivo. The results showed that the total secreted protein concentration in fermentation supernatant was up to 2820 mg/L (29 °C) after 120-h induction in a 5-L fermentor. The yield of NZX reached up to 965 mg/L with a purity of 92.6%. The recombinant expressed NZX had a strong antimicrobial activity, high stability, and low toxicity. The minimal inhibitory concentrations (MICs) of NZX and ceftriaxone (CRO) against Gram-positive bacteria were 0.46 to 0.91 μM and 6.04 to 12.09 μM, respectively. The time-killing curves showed that S. hyicus NCTC10350 was killed completely by 2× and 4 × MIC of NZX within 24 h. NZX also exhibited the intracellular activity against S. hyicus in Hacat cells. After treatment with NZX (10 mg/kg) and CRO (60 mg/kg), the survival rates of mice were 100% and 83.3%, respectively. NZX inhibited the bacterial translocation, downregulated pro-inflammatory cytokines (TNF-α/IL-1β/IL-6), upregulated the anti-inflammatory cytokine (IL-10), and ameliorated multiple-organ injuries (the liver, spleen, lung, and kidney). This study provides evidence that the expressed NZX has the potential to become a powerful candidate as novel antimicrobial agents against S. hyicus infections. [ABSTRACT FROM AUTHOR]

Pathogenic Escherichia coli can cause fatal diarrheal diseases in both animals and humans. However, no antibiotics or antimicrobial peptides (AMPs) can adequately kill resistant bacteria and clear bacterial endotoxin, lipopolysaccharide (LPS) which leads to inflammation and sepsis. Here, the LPS-targeted smart chimeric peptides (SCPs)-A6 and G6 are generated by connecting LPS-targeting peptide-LBP14 and killing domain-N6 via different linkers. Rigid and flexible linkers retain the independent biological activities from each component. SCPs-A6 and G6 exert low toxicity and no bacterial resistance, and they more rapidly kill multiple-drug-resistant E. coli and more effectively neutralize LPS toxicity than N6 alone. The SCPs can enhance mouse survival more effectively than N6 or polymyxin B and alleviate lung injuries by blocking mitogen-activated protein kinase and nuclear factor kappa-B p65 activation. These findings uniquely show that SCPs-A6 and G6 may be promising dual-function candidates as improved antibacterial and anti-endotoxin agents to treat bacterial infection and sepsis. Wang ZL and Wang XM design bactericidal peptides in which an antimicrobial domain is fused to a domain that facilitates the neutralisation of lipoplysaccaride (LPS) to prevent inflammation associated with the targeting of Gram-negative bacteria. They characterise their properties and structures, and show their efficiency in vitro and in vivo. [ABSTRACT FROM AUTHOR]

Transition metal sulfide nanoparticles provide efficient tumor photothermal therapy under near-infrared light, while suffering from poor chemical stability and biocompatibility. Protein scaffolds are attractive templates to fabricate various inorganic nanostructures, due to their inherent capabilities of molecular recognition and self-assembly characteristics. Herein, a straightforward method is demonstrated for efficiently synthesizing CuS nanoparticles inside the inner cavity of the genetically modified hepatitis B core protein virus-like particles (HBc VLPs) via the affinity of histidine tags to copper ions. The monodispersed and well-defined HBc-CuS VLPs have been yielded with high efficiency and used as a potential photothermal agent for cancer therapy due to their excellent photothermal conversion efficiency, high cellular uptake and biocompatibility. [ABSTRACT FROM AUTHOR]

As a large number of small base stations have been deployed in dense heterogeneous networks, the increasing cost of energy has become a challenging issue. In this paper, we propose an optimized clustering-based sleep strategy to release the power consumption and interference in the system. First, we group the small base stations with large interference as a cluster in which the binary particle swarm optimization (BPSO) algorithm is used to formulate a sleep strategy for small base stations in the clusters. Since the small base stations between clusters have less interference, the whole spectrum resources can be shared in all clusters and the orthogonal spectrum resources are allocated for the small base stations in the same cluster. The strategy effectively restrains the co-tier interference in the system. Furthermore, a separate sleep strategy is applied for each cluster to improve the sleep and activation efficiency of the small base stations. The simulation results show that the proposed sleep strategy can improve the satisfaction of user equipment and reduce the power consumption. As the increasing number of user equipment, the outage probability of the system can be reduced effectively. [ABSTRACT FROM AUTHOR]

There is an urgent need to discover new active drugs to combat methicillin-resistant Staphylococcus aureus, which is a serious threat to humans and animals and incompletely eliminated by antibiotics due to its intracellular accumulation in host cells, production of biofilms, and persisters. Fungal defensin-like peptides (DLPs) are emerging as a potential source of new antibacterial drugs due to their potent antibacterial activity. In this study, nine novel fungal DLPs were firstly identified by querying against UniProt databases and expressed in Pichia pastoris, and their antibacterial and anti-biofilm ability were tested against multidrug-resistant (MDR) S. aureus. Results showed that among them, P2, the highest activity and expression level, showed low toxicity, no resistance, and high stability. Minimal inhibitory concentrations (MICs) of P2 against Gram-positive bacteria were < 2 μg/mL. P2 exhibited the potent activity against intracellular MDR S. aureus (bacterial reduction in 80–97%) in RAW264.7 macrophages. P2 bound to/disrupted bacterial DNA, wrinkled outer membranes and permeabilized cytoplasmic membranes, but maintained the integrity of bacterial cells. P2 inhibited/eradicated the biofilm and killed 99% persister bacteria, which were resistant to 100× MIC vancomycin. P2 upregulated the anti-inflammatory cytokine (IL-10) and downregulated pro-inflammatory cytokines (TNF-α/IL-1β) and chemokine (MCP-1) levels in RAW 264.7 macrophages and in mice, respectively. Five milligram per kilogram P2 enhanced the survival of S. aureus-infected mice (100%), superior to vancomycin (30 mg/kg), inhibited the bacterial translocation, and alleviated multiple-organ injuries (liver, spleen, kidney, and lung). These data suggest that P2 may be a candidate for novel antimicrobial agents against MDR staphylococcal infections. [ABSTRACT FROM AUTHOR]

Bovine lactoferricin (LfcinB) has potent antibacterial, antifungal and antiparasitic activities but is also hemolytic. Our objective was to identify LfcinB17-31 derivatives with reduced hemolysis and improved antimicrobial activity via substituting Cys3, Arg4, Gln7, Met10, and Gly14 with more hydrophobic residues. Two peptides, Lfcin4 and Lfcin5, showed higher activity against Staphylococcus aureus and Salmonella enteritidis and lower hemolytic activity than the parent peptide LfcinB17-31. These peptides permeabilized the outer and inner membranes of S. enteritidis; however, Lfcin5 did not permeabilize the inner membrane of S. aureus. Gel retardation and circular dichroism spectra showed that Lfcin4 and Lfcin5 bound to bacterial genomic DNA. Lfcin4 inhibited DNA, RNA and protein synthesis. Both peptides induced the peeling of membranes and the lysis of S. enteritidis. At doses of 10 and 15 mg/kg, Lfcin4 and Lfcin5 reduced the bacterial counts in infected thigh muscles by 0.03-0.10 and 0.05-0.63 log10 CFU/g of tissue, respectively, within 10 h. Lfcin4 and Lfcin5 enhanced the survival rate of endotoxemic mice; reduced serum IL-6, IL-1β and TNF-α levels; and protected mice from lipopolysaccharide-induced lung injury. These data suggest that Lfcin4 and Lfcin5 may be antimicrobial and anti-endotoxin peptides that could serve as the basis for the development of dual-function agents. [ABSTRACT FROM AUTHOR]

NZ2114 is a promising candidate for therapeutic application owing to its potent activity to Staphylococcus aureus. Our objective was to identify NZ2114 derivatives with improved activity through substitution of His16 and His18 with residues Arginine and Lysine. Eight mutants were designed and expressed in Pichia pastoris X-33 via pPICZαA. Five of them exhibited strong antimicrobial activity against S. aureus at low minimal inhibitory concentrations (MICs) of 0.057-0.454 μM. Among them, H1, H2, and H3 showed ideal pharmacodynamic effects on methicillin-resistant S. aureus ATCC43300. The total protein level of H1, H2, and H3 reached 1.70, 1.77 and 1.54 g/l at 120 h of induction in the 5-l fermenter, respectively. They killed over 99.9% of pathogens within 1.5 h at 2× and 4× MIC. The post antibiotic effect of H1, H2 and H3 to S. aureus ATCC43300 was 2.94, 1.75 and 1.55 h at 2× MIC, which was similar with their original peptide NZ2114 (1.43 h) and vancomycin (1.72 h). The fractional inhibitory concentration index (FICI) indicated indifferent effects between H1, H2, H3 and vancomycin, ampicillin, rifampicin. Additionally, they had low hemolysis and high stability in different environments (temperature, pH, proteases, and saline ions). All results indicate that H1, H2, and H3 can be produced in large-scale and have potential as therapeutic drugs against MRSA. [ABSTRACT FROM AUTHOR]

NZ2114 is a promising candidate for therapeutic application owing to potent activity to gram-positive bacterium such as Streptococcus pneumoniae and Staphylococcus aureus. This work is the first report to describe the in vitro and in vivo antibacterial characteristics of NZ2114 against Streptococcus suis. It exhibited strong antimicrobial activity against S. suis type 2 strains CVCC 606, CVCC 3309, and CVCC 3928 at a low minimal inhibitory concentration (MIC) of 0.03-0.06 μM. The NZ2114 killed over 99.9% of tested S. suis CVCC 606 in Mueller-Hinton medium within 4 h when treated with 4 × MIC. It caused only less than 0.25% hemolytic activity in the concentration of 256 μg/ml. Additionally, NZ2114 exhibited potent in vivo activity to S. suis. All mice were survival when the dosage was low to 0.2 mg/kg. Over 99% of S. suis cells were killed within 4 h in blood, lung, liver and spleen with dosage of 10, 20, and 40 mg/kg in mice peritonitis models and no pathogen were detected after 24 h of treatment. Further, no pathological phenomenon in lung and low level of inflammatory cytokines in blood were detected. These results indicate that NZ2114 has the potential to be a new antimicrobial agent candidate for the clinical treatment of infection caused by S. suis type 2. [ABSTRACT FROM AUTHOR]

A correction to the article "Design, expression, and characterization of a novel targeted plectasin against methicillin-resistant Staphylococcus aureus" by Ruoyu Mao and colleagues that was published in the March 2013 issue is presented.

A novel antimicrobial peptide MP1106 was designed based on the parental peptide plectasin with four mutational sites and a high level of expression in Pichia pastoris X-33 via the pPICZαA plasmid was achieved. The concentration of total secreted protein in the fermented supernatant was 2.134 g/l (29 °C), and the concentration of recombinant MP1106 (rMP1106) reached 1,808 mg/l after a 120-h induction in a 5-l fermentor. The rMP1106 was purified using a cation-exchange column, and the yield was 831 mg/l with 94.68 % purity. The sample exhibited a narrow spectrum against some Gram-positive bacteria and strong antimicrobial activity against Staphylococcus aureus at low minimal inhibitory concentrations (MICs) of 0.014, 1.8, 0.45, and 0.91 μM to S. aureus strains ATCC 25923, 29213, 6538, and 43300, respectively. Meanwhile, rMP1106 showed potent activity (0.03-1.8 μM) against 20 clinical isolates of methicillin-resistant S. aureus (MRSA). In addition, rMP1106 exhibited a broad range of thermostability from 20 to 100 °C. The higher antimicrobial activity of rMP1106 was maintained in neutral and alkaline environments (pH 6, 8, and 10), and its activity was slightly reduced in acidic environments (pH 2 and 4). The rMP1106 was resistant to the digestion of pepsin, snailase, and proteinase K and was sensitive to trypsin. It exhibited hemolytic activity of only 1.16 % at a concentration of 512 μg/ml and remained stable in human serum at 37 °C for 24 h. Furthermore, the activity of rMP1106 was minorly affected by 10 mM dithiothreitol and 20 % dimethylsulfoxide. Our results indicate that MP1106 can be produced on a large scale and has potential as a therapeutic drug against S. aureus. [ABSTRACT FROM AUTHOR]

The programmed death-1 (PD-1) molecule is mainly expressed on functionally 'exhausted' CD8 T cells, dampening the host antitumor immune response. We evaluated the ratio between effective and regulatory T cells (Tregs) and PD-1 expression as a prognostic factor for operable breast cancer patients. A series of 218 newly diagnosed invasive breast cancer patients who had undergone primary surgery at Ruijin Hospital were identified. The influence of CD8 cytotoxic T lymphocytes, FOXP3 (Treg cell marker), and PD-1 immune cell counts on prognosis was analyzed utilizing immunohistochemistry. Both PD-1 immune cells and FOXP3 Tregs counts were significantly associated with unfavorable prognostic factors. In bivariate, but not multivariate analysis, high tumor infiltrating PD-1 cell counts correlated with significantly shorter patient survival. Our results suggest a prognostic value of the PD-1 immune cell population in such breast cancer patients. Targeting the PD-1 pathway may be a feasible approach to treating patients with breast cancer. [ABSTRACT FROM AUTHOR]

NZ2114, a new variant of plectasin, was overexpressed in Pichia pastoris X-33 via pPICZαA for the first time. The total secreted protein of fermentation supernatant reached 2,390 mg/l (29 °C) and 2,310 mg/l (25 °C), and the recombinant NZ2114 (rNZ2114) reached 860 mg/l (29 °C) and 1,309 mg/l (25 °C) at 96 h induction in a 5-l fermentor, respectively.The rNZ2114 was purified by cation exchange chromatography, and its yield was 583 mg/l with 94.8 % purity. The minimal inhibitory concentration (MIC) of rNZ2114 to four ATCC strains of Staphyloccocus aureus was evaluated from 0.028 to 0.90 μM. Meanwhile, it showed potent activity (0.11-0.90 μM) to 20 clinical isolates of MRSA. The rNZ2114 killed over 99.9 % of tested S. aureus (ATCC 25923 and ATCC 43300) in Mueller-Hinton medium within 6 h when treated with 4 × MIC. The postantibiotic effect of rNZ2114 to S. aureus ATCC 25923 and ATCC 43300 was 18.6-45.6 and 1.7-3.5 h under 1×, 2×, and 4× MIC, respectively. The fractional inhibitory concentration index (FICI) indicated a synergistic effect between rNZ2114 and kanamycin, streptomycin, and vancomycin against S. aureus ATCC 25923 (FICI = 0.125), and additivity between rNZ2114 and ampicillin, spectinomycin (FICI = 0.625), respectively. To S. aureus ATCC 43300 [methicillin-resistant S. aureus (MRSA)], rNZ2114 showed a synergistic effect (FICI = 0.125-0.3125) with kanamycin, ampicillin, streptomycin, and vancomycin, and antagonism with spectinomycin (FICI = 8.0625). The rNZ2114 caused only less than 0.1 % hemolytic activity in the concentration of 128 μg/ml, and showed a good thermostability from 20 to 80 °C. In addition, it exhibited the highest activity at pH 8.0. These results suggested that large-scale production of NZ2114 is feasible using the P. pastoris expression system, and it could be a new potential antimicrobial agent for the prevention and treatment of S. aureus especially for MRSA infections. [ABSTRACT FROM AUTHOR]