Characterization of TistH, a multifunctional peptide from the scorpion Tityus stigmurus: Structure, cytotoxicity and antimicrobial activity

Antimicrobial Potential of Scorpion-Venom-Derived Peptides

The frequent and irrational use of antibiotics by humans has led to the escalating rise of antimicrobial resistance (AMR) with a high rate of morbidity-mortality worldwide, which poses a challenge to the development of effective treatments. A large number of host defense peptides from different organisms have gained interest due to their broad antibacterial spectrum, rapid action, and low target resistance, implying that these natural sources might be a new alternative to antimicrobial drugs. As important effectors of prey capture, defense against other animal attacks, and competitor deterrence, scorpion venoms have been developed as important candidate sources for modern drug development. With the rapid progress of bioanalytical and high throughput sequencing techniques, more and more scorpion-venom-derived peptides, including disulfide-bridged peptides (DBPs) and non-disulfide-bridged peptides (NDBPs), have been recently identified as having massive pharmacological activities in channelopathies, pathogen infections, and cancer treatments. In this review, we summarize the molecular diversity and corresponding structural classification of scorpion venom peptides with antibacterial, antifungal, and/or antiparasitic activity. We also aim to improve the understanding of the underlying mechanisms by which scorpion-venom-derived peptides exert these antimicrobial functions, and finally highlight their key aspects and prospects for antimicrobial therapeutic or pharmaceutical application.

Harnessing the potency of scorpion venom-derived proteins: applications in cancer therapy

Despite breakthroughs in the development of cancer diagnosis and therapy, most current therapeutic approaches lack precise specificity and sensitivity, resulting in damage to healthy cells. Selective delivery of anti-cancer agents is thus an important goal of cancer therapy. Scorpion venom (SV) and/or body parts have been used since early civilizations for medicinal purposes, and in cultures, SV is still applied to the treatment of several diseases including cancer. SV contains numerous active micro and macromolecules with diverse pharmacological effects. These include potent anti-microbial, anti-viral, anti-inflammatory, and anti-cancer properties. This review focuses on the recent advances of SV-derived peptides as promising anti-cancer agents and their diagnostic and therapeutic potential applications in cancers such as glioma, breast cancer, prostate cancer, and colon cancer. Well-characterized SV-derived peptides are thus needed to serve as potent and selective adjuvant therapy for cancer, to significantly enhance the patients' survival and wellbeing.

Exploring the Potential of Isalo Scorpion Cytotoxic Peptide in Enhancing Gill Barrier Function and Immunity in Grass Carp (Ctenopharyngodon idella) Infected with Flavobacterium columnare

The objective of this research was to investigate how dietary antimicrobial peptides (AMP), namely, Isalo scorpion cytotoxic peptide (IsCT), affect the gill physical barrier function and immune function of grass carp challenged with Flavobacterium columnare (F. columnare). Five hundred forty grass carp were randomly allocated to six groups and fed to varying levels of IsCT in the diet (0, 0.6, 1.2, 1.8, 2.4, and 3.0 mg/kg diet) for a duration of 60 days. Afterward, the grass carps faced a challenge from F. columnare. The results revealed that the use of optimal IsCT dramatically mitigated gill damage in grass carp that were infected with F. columnare. Additionally, IsCT exhibited a notable enhancement in gill antioxidant capabilities, as evidenced by a significant reduction in ROS, MDA, and PC levels, an elevation in antioxidant enzyme activities, and an upregulation of antioxidant-related genes and Nrf2 mRNA levels. Conversely, the expression of Keap1a and Keap1b mRNA was decreased. Besides, IsCT exhibited its capability to inhibit apoptosis via downregulating the mRNA levels of caspase-2, caspase-3, caspase-7, caspase-8, caspase-9, Apaf1, Fasl, Bax, and JNK while concurrently increasing the mRNA levels of Bcl-2, Mcl-1, and IAP in fish gills. Additionally, IsCT promoted the integrity of tight junction barrier by increasing the gene expression of claudin-b, claudin-c, claudin-3c, ZO-1, ZO-2b, occludin, and JAM while suppressing MLCK signaling. Additionally, optimal dietary IsCT improved antibacterial ability, as evidenced by heightened LZ, ACP activities, and elevated levels of C3, C4, and IgM. Additionally, there was an upregulation in β-defensin-1, LEAP-2A, LEAP-2B, hepcidin, and mucin-2 mRNA expression in the gills. Simultaneously, the inclusion of optimal dietary IsCT in the diet resulted in improved gill immunity barriers through the reduction of proinflammatory cytokine mRNA levels and the increase in the expression of anti-inflammatory cytokine mRNA levels. This was partly facilitated by the IκBa/NF-κB p65 signaling pathway and TOR/S6K1 signaling pathways in the gills of grass carp. Therefore, supplementing the diet with IsCT has potential advantages in enhancing gill health by improved physical barriers and immunity in grass carp. Based on LZ activity and against lipid peroxidation, optimum IsCT concentrations in on-growing grass carp (136.88 ± 0.72 g) were found to be 1.68 and 1.54 mg/kg diet, respectively.

The complex repertoire of Tityus spp. venoms: Advances on their composition and pharmacological potential of their toxins

Animal venoms are a rich and complex source of components, including peptides (such as neurotoxins, anionic peptides and hypotensins), lipids, proteins (such as proteases, hyaluronidases and phospholipases) and inorganic compounds, which affect all biological systems of the envenoming victim. Their action may result in a wide range of clinical manifestations, including tachy/bradycardia, hyper/hypotension, disorders in blood coagulation, pain, edema, inflammation, fever, muscle paralysis, coma and even death. Scorpions are one of the most studied venomous animals in the world and interesting bioactive molecules have been isolated and identified from their venoms over the years. Tityus spp. are among the scorpions with high number of accidents reported in the Americas, especially in Brazil. Their venoms have demonstrated interesting results in the search for novel agents with antimicrobial, anti-viral, anti-parasitic, hypotensive, immunomodulation, anti-insect, antitumor and/or antinociceptive activities. Furthermore, other recent activities still under investigation include drug delivery action, design of anti-epileptic drugs, investigation of sodium channel function, treatment of erectile disfunction and priapism, improvement of scorpion antivenom and chelating molecules activity. In this scenario, this paper focuses on reviewing advances on Tityus venom components mainly through the modern omics technologies as well as addressing potential therapeutic agents from their venoms and highlighting this abundant source of pharmacologically active molecules with biotechnological application.

Exploring the frontiers of therapeutic breadth of antifungal peptides: A new avenue in antifungal drugs

The growing prevalence of fungal infections alongside rising resistance to antifungal drugs poses a significant challenge to public health safety. At the close of the 2000s, major pharmaceutical firms began to scale back on antimicrobial research due to repeated setbacks and diminished economic gains, leaving only smaller companies and research labs to pursue new antifungal solutions. Among various natural sources explored for novel antifungal compounds, antifungal peptides (AFPs) emerge as particularly promising. Despite their potential, AFPs receive less focus than their antibacterial counterparts. These peptides have been sourced extensively from nature, including plants, animals, insects, and especially bacteria and fungi. Furthermore, with advancements in recombinant biotechnology and computational biology, AFPs can also be synthesized in lab settings, facilitating peptide production. AFPs are noted for their wide-ranging efficacy, in vitro and in vivo safety, and ability to combat biofilms. They are distinguished by their high specificity, minimal toxicity to cells, and reduced likelihood of resistance development. This review aims to comprehensively cover AFPs, including their sources-both natural and synthetic-their antifungal and biofilm-fighting capabilities in laboratory and real-world settings, their action mechanisms, and the current status of AFP research.

ONE-SENTENCE SUMMARY

This comprehensive review of AFPs will be helpful for further research in antifungal research.

Investigating the inhibitory and penetrating properties of three novel anticancer and antimicrobial scorpion peptides via molecular docking and molecular dynamic simulation

The two types of bladder cancer, muscle invasive and non-muscle invasive (NMIBC), are among the most prevalent cancers worldwide. Despite this, even though muscle-invasive bladder cancer is more deadly, NMIBC requires more therapy due to a greater recurrence rate and more extended and expensive care. Immunotherapy, intravesical chemotherapy, cystoscopy, and transurethral resection (TUR) are among the treatments available. Crude scorpion venomand purified proteins and peptides, can suppress cancer metastasis in an in vitro or in vivo context, suppress cancer growth, halt the cell cycle, and cause cell apoptosis, according to an increasing number of experimental and preclinical studies. In this research, three novels discovered peptides (P2, P3 and P4. ProteomeXchange: PXD036231) from Buthotus saulcyi and, Odontobuthus doriae scorpions were used along with a peptide called pantinin (as a control). The phylogenetic tree showed that the peptides belong to Chaperonin HSP60, Chrysophsin2 and Pheromone-binding protein2, respectively. These peptides were docked with four known antigens, BAGE, BLCAP, PRAME and ROR1 related to bladder cancer and three bacterial antigens FliC, FliD and FimH to investigate their antimicrobial and anticancer properties. The results showed that peptides 2 and 3 have the best binding rate. The MD simulation results also confirmed the binding of peptides 2 and 3 to antigens. The penetration power of peptides 2 and 3 in the membrane of cancer cells and bacterial cells was also simulated, and the results of RMSD and PD confirmed it. QSAR suggests that peptides 2 and 3 can act as anti-cancer and anti-microbial peptides.Communicated by Ramaswamy H. Sarma.

Bioactive peptides from scorpion venoms: therapeutic scaffolds and pharmacological tools

Evolution and natural selection have endowed animal venoms, including scorpion venoms, with a wide range of pharmacological properties. Consequently, scorpions, their venoms, and/or their body parts have been used since time immemorial in traditional medicines, especially in Africa and Asia. With respect to their pharmacological potential, bioactive peptides from scorpion venoms have become an important source of scientific research. With the rapid increase in the characterization of various components from scorpion venoms, a large number of peptides are identified with an aim of combating a myriad of emerging global health problems. Moreover, some scorpion venom-derived peptides have been established as potential scaffolds helpful for drug development. In this review, we summarize the promising scorpion venoms-derived peptides as drug candidates. Accordingly, we highlight the data and knowledge needed for continuous characterization and development of additional natural peptides from scorpion venoms, as potential drugs that can treat related diseases.

Antifungal activity of Rhopalurus crassicauda venom against Candida spp

Fungal infections are becoming a serious problem of human diseases, being one of the most important fungal pathogens the yeast of the genus Candida. So far, fungal infection treatment faces different challenges, including the limited number of therapeutic drugs. Scorpions are known to be a valuable source of biologically active molecules, especially of peptide-derived molecules with a variety of biological effects and useful, lead compounds for drugs development. Here, we pioneer described the antifungal effect of venom, mucus, and the major toxin (Rc1) from Rhopalurus crassicauda scorpion. These results support the potential for Rc1 to be further investigated as a novel antifungal therapeutic to treat Candida infections.

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Fungal infection treatment presents limited number of therapeutic drugs.

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R. crassicauda venom and major toxin inhibit Candida spp. grown in vitro.

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R. crassicauda venom-derived toxins may be a rich source of antifungal compounds.

TanP: A Multifunctional Anionic Peptide From Tityus stigmurus Scorpion Venom

Anionic peptides of scorpions are molecules rich in aspartic and/or glutamic acid residues and correspond to a class of peptides without disulfide bonds that are still little explored. TanP is a linear anionic peptide (50 amino acid residues and net charge -20) present in the venom gland of the scorpion, Tityus stigmurus, with chelating properties for Cu2+ ion and immunomodulatory properties. The therapeutic application of chelating molecules is related to cases of acute or chronic intoxication by metals, neurodegenerative diseases, hematological diseases, healing of skin wounds, cardiovascular diseases, and cancer. In this approach, the chelating activity of TanP was evaluated in relation to new metal ions (Fe2+ and Zn2+) of biological importance, as well as its antioxidant, hemostatic, immunomodulatory, and healing potential, aiming to expand the biological and biotechnological potential of this peptide. TanP (25 µM) was able to form stable complexes with Fe2+ in a ratio of 1:5 (TanP: Fe2+). Theoretical results suggest that TanP can work as a sensor to identify and quantify Fe2+ ions. The fluorescence intensity of TanP (1.12 µM) decreased significantly after the addition of Fe2+, obtaining the highest ratio 1: 7.4 (TanP: Fe2+) that led to the lowest fluorescence intensity. For Zn2+, no relevant spectral change was noted. TanP (50 µM) showed a maximum of 3% of hemolytic activity, demonstrating biocompatibility, as well as exhibiting a 1,1-diphenyl-2-picrylhydrazyl radical-scavenging activity of above 70% at all the concentrations tested (1-25 μM), and 89.7% iron-chelating activity at 25 μM and 96% hydroxyl radical-scavenging activity at 73.6 μM. In addition, TanP (12.5 and 25 µM) revealed an anticoagulant effect, prolonging the clotting time in prothrombin time and activated partial thromboplastin time assays, with no fibrinogenolytic activity. TanP (12.5 and 25 µM) induced the release of TNF-α by murine macrophages, in the absence of lipopolysaccharides, with a concentration-dependent increase and also stimulated the migration of 3T3 cells in the in vitro healing assay. Thus, TanP revealed a multifunctional potential, being useful as a prototype for the development of new therapeutic and biotechnological agents.

Immunomodulatory Responses of Two Synthetic Peptides against Salmonella Typhimurium Infection

In vitro assays of phagocytic activity showed that the peptide Pin2[G] stimulates phagocytosis in BMDM cells from 0.15 to 1.25 μg/mL, and in RAW 264.7 cells at 0.31 μg/mL. In the same way, the peptide FA1 induced phagocytosis in BMDM cells from 1.17 to 4.69 μg/mL and in RAW 264.7 cells at 150 μg/mL. Cytokine profiles of uninfected RAW 264.7 showed that Pin2[G] increased liberation TNF (from 1.25 to 10 μg/mL) and MCP-1 (10 μg/mL), and FA1 also increased the release of TNF (from 18.75 to 75 μg/mL) but did not increase the liberation of MCP-1. In RAW 264.7 macrophages infected with Salmonella enterica serovar Typhimurium, the expression of TNF increases with Pin2[G] (1.25-10 μg/mL) or FA1 (18.75-75 μg/mL). In these cells, FA1 also increases the expression of IL-12p70, IL-10 and IFN-γ when applied at concentrations of 37.5, 75 and 150 μg/mL, respectively. On the other hand, stimulation with 1.25 and 10 μg/mL of Pin2[G] promotes the expression of MCP-1 and IL-12p70, respectively. Finally, peptides treatment did not resolve murine gastric infection, but improves their physical condition. Cytokine profiles showed that FA1 reduces IFN-γ and MCP-1 but increases IL-10, while Pin2[G] reduces IFN-γ but increases the liberation of IL-6 and IL-12p70. This data suggests a promising activity of FA1 and Pin2[G] as immunomodulators of gastric infections in S. Typhimurium.

Suppression of a BAHD acyltransferase decreases p-coumaroyl on arabinoxylan and improves biomass digestibility in the model grass Setaria viridis

Grass cell walls have hydroxycinnamic acids attached to arabinosyl residues of arabinoxylan (AX), and certain BAHD acyltransferases are involved in their addition. In this study, we characterized one of these BAHD genes in the cell wall of the model grass Setaria viridis. RNAi silenced lines of S. viridis (SvBAHD05) presented a decrease of up to 42% of ester-linked p-coumarate (pCA) and 50% of pCA-arabinofuranosyl, across three generations. Biomass from SvBAHD05 silenced plants exhibited up to 32% increase in biomass saccharification after acid pre-treatment, with no change in total lignin. Molecular dynamics simulations suggested that SvBAHD05 is a p-coumaroyl coenzyme A transferase (PAT) mainly involved in the addition of pCA to the arabinofuranosyl residues of AX in Setaria. Thus, our results provide evidence of p-coumaroylation of AX promoted by SvBAHD05 acyltransferase in the cell wall of the model grass S. viridis. Furthermore, SvBAHD05 is a promising biotechnological target to engineer crops for improved biomass digestibility for biofuels, biorefineries and animal feeding.

Recent Updates on Antifungal Peptides

The current trend of increment in the frequency of antifungal resistance has brought research into an era where new antifungal compounds with novel mechanisms of action are required. Natural antimicrobial peptides, which are ubiquitous components of innate immunity, represent their candidature for novel antifungal peptides. Various antifungal peptides have been isolated from different species ranging from small marine organisms to insects and from various other living species. Based on these peptides, various mimetics of antifungal peptides have also been synthesized using non-natural amino acids. Utilization of these antifungal peptides is somehow limited due to their toxic and unstable nature. This review discusses recent updates and future directions of antifungal peptides, for taking them to the shelf from the bench.

Antimicrobial Peptides: a New Frontier in Antifungal Therapy

Invasive fungal infections in humans are generally associated with high mortality, making the choice of antifungal drug crucial for the outcome of the patient. The limited spectrum of antifungals available and the development of drug resistance represent the main concerns for the current antifungal treatments, requiring alternative strategies. Antimicrobial peptides (AMPs), expressed in several organisms and used as first-line defenses against microbial infections, have emerged as potential candidates for developing new antifungal therapies, characterized by negligible host toxicity and low resistance rates. Most of the current literature focuses on peptides with antibacterial activity, but there are fewer studies of their antifungal properties. This review focuses on AMPs with antifungal effects, including their in vitro and in vivo activities, with the biological repercussions on the fungal cells, when known. The classification of the peptides is based on their mode of action: although the majority of AMPs exert their activity through the interaction with membranes, other mechanisms have been identified, including cell wall inhibition and nucleic acid binding. In addition, antifungal compounds with unknown modes of action are also described. The elucidation of such mechanisms can be useful to identify novel drug targets and, possibly, to serve as the templates for the synthesis of new antimicrobial compounds with increased activity and reduced host toxicity.

Biology, venom composition, and scorpionism induced by brazilian scorpion Tityus stigmurus (Thorell, 1876) (Scorpiones: Buthidae): A mini-review

Scorpionism is a serious public health problem in various regions of the world. In Brazil, a high number of accidents by scorpions have been reported. From 2014 to 2018, about 547,000 cases were recorded, resulting in 466 deaths. The scorpion Tityus stigmurus is the predominant species in the northeast of Brazil, being responsible for most scorpionism cases in this region. With the aid of the transcriptomic approach of the venom gland of this species, components as neurotoxins, antimicrobials, metal chelating peptides and hypotensins, have been identified and characterized in silico, showing different biologic activity in vitro. In addition, the neuronal, pancreatic, renal, and enzymatic effects have been demonstrated for the crude T. stigmurus venom. Therefore, the T. stigmurus scorpion venom constitutes a rich arsenal of bioactive molecules with high potential for therapeutic and biotechnological application.

Scorpion Venom: Detriments and Benefits

Scorpion venom may cause severe medical complications and untimely death if injected into the human body. Neurotoxins are the main components of scorpion venom that are known to be responsible for the pathological manifestations of envenoming. Besides neurotoxins, a wide range of other bioactive molecules can be found in scorpion venoms. Advances in separation, characterization, and biotechnological approaches have enabled not only the development of more effective treatments against scorpion envenomings, but have also led to the discovery of several scorpion venom peptides with interesting therapeutic properties. Thus, scorpion venom may not only be a medical threat to human health, but could prove to be a valuable source of bioactive molecules that may serve as leads for the development of new therapies against current and emerging diseases. This review presents both the detrimental and beneficial properties of scorpion venom toxins and discusses the newest advances within the development of novel therapies against scorpion envenoming and the therapeutic perspectives for scorpion toxins in drug discovery.

Design of bioactive peptides derived from CART sequence isolated from the toadfish Thalassophryne nattereri

The emergence of bacterial resistance due to the indiscriminate use of antibiotics warrants the need for developing new bioactive agents. In this context, antimicrobial peptides are highly useful for managing resistant microbial strains. In this study, we report the isolation and characterization of peptides obtained from the venom of the toadfish Thalassophryne nattereri. These peptides were active against Gram-positive and Gram-negative bacteria and fungi. The primary amino acid sequences showed similarity to Cocaine and Amphetamine Regulated Transcript peptides, and two peptide analogs-Tn CRT2 and Tn CRT3-were designed using the AMPA algorithm based on these sequences. The analogs were subjected to physicochemical analysis and antimicrobial screening and were biologically active at concentrations ranging from 2.1 to 13 µM. Zeta potential analysis showed that the peptide analogs increased the positive charge on the cell surface of Gram-positive and Gram-negative bacteria. The toxicity of Tn CRT2 and Tn CRT3 were analyzed in vitro using a hemolytic assay and tetrazolium salt reduction in fibroblasts and was found to be significant only at high concentrations (up to 40 µM). These results suggest that this methodological approach is appropriate to design novel antimicrobial peptides to fight bacterial infections and represents a new and promising discovery in fish venom.

Optimization of Scorpion Protein Extraction and Characterization of the Proteins' Functional Properties

Scorpion has long been used in traditional Chinese medicine, because whole scorpion body extract has anti-cancer, analgesic, anti-thrombotic blood anti-coagulation, immune modulating, anti-epileptic, and other functions. The purpose of this study was to find an efficient extraction method and investigate some of physical and chemical parameters, like water solubility, emulsification, foaming properties, and oil-holding capacity of obtained scorpion proteins. Response surface methodology (RSM) was used for the determination of optimal parameters of ultrasonic extraction (UE). Based on single factor experiments, three factors (ultrasonic power (w), liquid/solid (mL/g) ratio, and extraction time (min)) were used for the determination of scorpion proteins (SPs). The order of the effects of the three factors on the protein content and yield were ultrasonic power > extraction time > liquid/solid ratio, and the optimum conditions of extraction proteins were as follows: extraction time = 50.00 min, ultrasonic power = 400.00 w, and liquid/solid ratio = 18.00 mL/g. For the optimal conditions, the protein content of the ultrasonic extraction and yield were 78.94% and 24.80%, respectively. The solubility, emulsification and foaming properties, and water and oil holding capacity of scorpion proteins were investigated. The results of this study suggest that scorpion proteins can be considered as an important ingredient and raw material for the creation of water-soluble supramolecular complexes for drugs.

Biodegradable cross-linked chitosan nanoparticles improve anti-Candida and anti-biofilm activity of TistH, a peptide identified in the venom gland of the Tityus stigmurus scorpion

Among several bioactive peptides identified from the venom glands of the Tityus stigmurus scorpion, one peptide with hypotensive action (TistH, Tityus stigmurus Hypotensin) showed multifunctional and biotechnological applications. The maximum efficacy of this class of compounds can be achieved by immobilizing it in specific and suitable biomaterials or suitable carriers. In this study, distinct entrapment methods of TistH in chitosan nanoparticles was tested using its incorporation (CN-TistH-Inc) or adsorption (CN-TistH-Ads) methods by ionotropic gelification. Physico-chemical properties as well as biocompatibility and antifungal efficacy were assessed for different samples. Atomic force microscopy and field emission gun scanning electronic microscopy images associated with particle size measurements demonstrated that the two methods induced cationic spherical, small (< 160 nm), and narrow-sized (PdI about 0.3) nanoparticles, even after peptide loading greater than 96.5%, which was confirmed using Fourier transform infrared spectroscopy. The colloidal suspensions showed to be stable for 8 weeks and were able to induce the desired slow in vitro peptide release. Cytotoxicity assays performed in normal cells originated from murine macrophages (RAW 264.7) and kidneys of African green monkeys (Vero E6) suggested biocompatibility of samples. The CN-TistH-Inc and CN-TistH-Ads showed a minimal inhibitory concentration of 89.2 μg.mL^-1 against Candida albicans, 11.1 μg.mL^-1 for C. parapsilosis and C. tropicalis, confirmed by minimum fungicidal concentrations assay. Moreover, the TistH-loaded cross-linked chitosan nanoparticles significantly reduced the biofilm formation of clinical yeast sepsis of C. tropicalis and C. krusei, as well as clinical yeasts of vulvovaginal candidiasis of C. albicans. In this approach, biodegradable nanocarriers prepared using simple and reproducible methods demonstrated the ability to deliver the TistH peptide from T. stigmurus and improve its antifungal efficacy.

Community ecology across bacteria, archaea and microbial eukaryotes in the sediment and seawater of coastal Puerto Nuevo, Baja California

Microbial communities control numerous biogeochemical processes critical for ecosystem function and health. Most analyses of coastal microbial communities focus on the characterization of bacteria present in either sediment or seawater, with fewer studies characterizing both sediment and seawater together at a given site, and even fewer studies including information about non-bacterial microbial communities. As a result, knowledge about the ecological patterns of microbial biodiversity across domains and habitats in coastal communities is limited-despite the fact that archaea, bacteria, and microbial eukaryotes are present and known to interact in coastal habitats. To better understand microbial biodiversity patterns in coastal ecosystems, we characterized sediment and seawater microbial communities for three sites along the coastline of Puerto Nuevo, Baja California, Mexico using both 16S and 18S rRNA gene amplicon sequencing. We found that sediment hosted approximately 500-fold more operational taxonomic units (OTUs) for bacteria, archaea, and microbial eukaryotes than seawater (p < 0.001). Distinct phyla were found in sediment versus seawater samples. Of the top ten most abundant classes, Cytophagia (bacterial) and Chromadorea (eukaryal) were specific to the sediment environment, whereas Cyanobacteria and Bacteroidia (bacterial) and Chlorophyceae (eukaryal) were specific to the seawater environment. A total of 47 unique genera were observed to comprise the core taxa community across environment types and sites. No archaeal taxa were observed as part of either the abundant or core taxa. No significant differences were observed for sediment community composition across domains or between sites. For seawater, the bacterial and archaeal community composition was statistically different for the Major Outlet site (p < 0.05), the site closest to a residential area, and the eukaryal community composition was statistically different between all sites (p < 0.05). Our findings highlight the distinct patterns and spatial heterogeneity in microbial communities of a coastal region in Baja California, Mexico.

Scorpion Venom-Toxins that Aid in Drug Development: A Review

Scorpion venom components have multifaceted orientation against bacterial, viral, fungal infections and other neuronal disorders. They can modulate the ion channels (K⁺, Na⁺, Cl⁻, Ca²⁺) of our body and this concept has been hypothesized in formulating pharmaceuticals. The triumphant achievement of these venom components as formulated anticancer agent in Phase I and Phase II clinical trials allure researchers to excavate beneficial venom components prohibiting DNA replication in malignant tumor cells. This review brings forth the achievements of Science and Technology in classifying the venom components as therapeutics and further application in drug product development.

Effects of Brazilian scorpion venoms on the central nervous system

In Brazil, the scorpion species responsible for most severe incidents belong to the Tityus genus and, among this group, T. serrulatus, T. bahiensis, T. stigmurus and T. obscurus are the most dangerous ones. Other species such as T. metuendus, T. silvestres, T. brazilae, T. confluens, T. costatus, T. fasciolatus and T. neglectus are also found in the country, but the incidence and severity of accidents caused by them are lower. The main effects caused by scorpion venoms - such as myocardial damage, cardiac arrhythmias, pulmonary edema and shock - are mainly due to the release of mediators from the autonomic nervous system. On the other hand, some evidence show the participation of the central nervous system and inflammatory response in the process. The participation of the central nervous system in envenoming has always been questioned. Some authors claim that the central effects would be a consequence of peripheral stimulation and would be the result, not the cause, of the envenoming process. Because, they say, at least in adult individuals, the venom would be unable to cross the blood-brain barrier. In contrast, there is some evidence showing the direct participation of the central nervous system in the envenoming process. This review summarizes the major findings on the effects of Brazilian scorpion venoms on the central nervous system, both clinically and experimentally. Most of the studies have been performed with T. serrulatus and T. bahiensis. Little information is available regarding the other Brazilian Tityus species.

Anti-Salmonella Activity Modulation of Mastoparan V1-A Wasp Venom Toxin-Using Protease Inhibitors, and Its Efficient Production via an Escherichia coli Secretion System

A previous study highlighted that mastoparan V1 (MP-V1), a mastoparan from the venom of the social wasp Vespula vulgaris, is a potent antimicrobial peptide against Salmonella infection, which causes enteric diseases. However, there exist some limits for its practical application due to the loss of its activity in an increased bacterial density and the difficulty of its efficient production. In this study, we first modulated successfully the antimicrobial activity of synthetic MP-V1 against an increased Salmonella population using protease inhibitors, and developed an Escherichia coli secretion system efficiently producing active MP-V1. The protease inhibitors used, except pepstatin A, significantly increased the antimicrobial activity of the synthetic MP-V1 at minimum inhibitory concentrations (determined against 10⁶ cfu/mL of population) against an increased population (10⁸ cfu/mL) of three different Salmonella serotypes, Gallinarum, Typhimurium and Enteritidis. Meanwhile, the E. coli strain harboring OmpA SS::MP-V1 was identified to successfully secrete active MP-V1 into cell-free supernatant, whose antimicrobial activity disappeared in the increased population (10⁸ cfu/mL) of Salmonella Typhimurium recovered by adding a protease inhibitor cocktail. Therefore, it has been concluded that our challenge using the E. coli secretion system with the protease inhibitors is an attractive strategy for practical application of peptide toxins, such as MP-V1.