Search Results (5)

Phytopathogenic bacteria and fungi significantly reduce fruit and vegetable yields, resulting in substantial economic losses. Conventional management relies on synthetic agrochemicals; however, their intensive use poses risks to human health, environmental integrity, and biodiversity. Snake venoms have evolved under selective pressure, developing specialized components with potent antimicrobial properties as part of a defense mechanism against prey-borne microorganisms. This study evaluated the inhibitory potential of Micrurus venoms against pathogens of agricultural interest and developed bioactive gelatin-based films incorporated with purified L-amino acid oxidases (LAAOs) as a novel biocontrol strategy. Venoms from M. ancoralis, M. mipartitus, and M. dumerilii exhibited significant growth inhibition against Xanthomonas and Fusarium strains. The primary active component was identified as LAAO through biological activity and mass spectrometry. Biofilms were formulated by incorporating M. ancoralis venom and its purified LAAO into a gelatin matrix. Physicochemical and microbiological characterization, alongside in situ assays on strawberries, demonstrated that the functionalized biofilms retained potent antimicrobial activity. Furthermore, LAAO incorporation did not significantly alter the physicochemical properties of the fruit but effectively extended shelf life by reducing weight loss and maintaining sensory appearance. These findings highlight the biotechnological potential of elapid venom components in the development of alternatives for phytopathogen control and active food packaging. Full article

In Colombia, Micrurus snakebites are classified as severe according to the national clinical care guidelines and must be treated with specific antivenoms. Unfortunately, these types of antivenoms are scarce in certain areas of the country and are currently reported as an unavailable vital medicine. To address this issue, La Universidad de Antioquia, through its spin-off Tech Life Saving, is leading a project to develop third-generation polyvalent freeze-dried antivenom. The goal is to ensure access to this therapy, especially in rural and dispersed areas. This project aims to evaluate the physicochemical and preclinical parameters (standard quality characteristics) of a lab-scale anti-elapid antivenom batch. The antivenom is challenged against the venoms of several Micrurus species, including M. mipartitus, M. dumerilii, M. ancoralis, M. dissoleucus, M. lemniscatus, M. medemi, M. spixii, M. surinamensis, and M. isozonus, following the standard quality characteristics set by the World Health Organization (WHO). The antivenom demonstrates an appearance consistent with standards, 100% solubility within 4 min and 25 s, an extractable volume of 10.39 mL, a pH of 6.04, an albumin concentration of 0.377 mg/mL (equivalent to 1.22% of total protein), and a protein concentration of 30.97 mg/mL. Importantly, it maintains full integrity of its F(ab′)₂ fragments and exhibits purity over 98.5%. Furthermore, in mice toxicity evaluations, doses up to 15 mg/mouse show no toxic effects. The antivenom also demonstrates a significant recognition pattern against Micrurus venoms rich in phospholipase A₂ (PLA₂) content, as observed in M. dumerilii, M. dissoleucus, and M. isozonus. The effective dose 50 (ED₅₀) indicates that a single vial (10 mL) can neutralize 2.33 mg of M. mipartitus venom and 3.99 mg of M. dumerilii venom. This new anti-elapid third-generation polyvalent and freeze-dried antivenom meets the physicochemical parameters set by the WHO and the regulators in Colombia. It demonstrates significant efficacy in neutralizing the venom of the most epidemiologically important Micrurus species in Colombia. Additionally, it recognizes seven other species of Micrurus venom with a higher affinity for venoms exhibiting PLA₂ toxins. Fulfilling these parameters represents the first step toward proposing a new pharmacological alternative for treating snakebites in Colombia, particularly in dispersed rural areas, given that this antivenom is formulated as a freeze-dried product. Full article

Micrurus dumerilii is a coral snake of clinic interest in Colombia. Its venom is mainly composed of phospholipases A₂ being MdumPLA₂ the most abundant protein. Nevertheless, Micrurus species produce a low quantity of venom, which makes it difficult to produce anticoral antivenoms. Therefore, in this work, we present the recombinant expression of MdumPLA₂ to evaluate its biological activities and its immunogenic potential to produce antivenoms. For this, a genetic construct rMdumPLA₂ was cloned into the pET28a vector and expressed heterologously in bacteria. His-rMdumPLA₂ was extracted from inclusion bodies, refolded in vitro, and isolated using affinity and RP-HPLC chromatography. His-rMdumPLA₂ was shown to have phospholipase A₂ activity, a weak anticoagulant effect, and induced myonecrosis and edema. The anti-His-rMdumPLA₂ antibodies produced in rabbits recognized native PLA₂, the complete venom of M. dumerilii, and a phospholipase from another species of the Micrurus genus. Antibodies neutralized 100% of the in vitro phospholipase activity of the recombinant toxin and a moderate percentage of the myotoxic activity of M. dumerilii venom in mice. These results indicate that His-rMdumPLA₂ could be used as an immunogen to improve anticoral antivenoms development. This work is the first report of an M. dumerilii functional recombinant PLA₂. Full article

In Colombia, the genus Micrurus includes 30 species, of which M. mipartitus and M. dumerilii are the most widely distributed. Micrurus causes less than 3% of the approximately 5000 cases of snakebite per year. The elapid envenomation caused by the snakes from the Micrurus genus, are characterized by the severity of their clinical manifestations, due to the venom neurotoxic components such as three-finger toxins (3FTx) and phospholipases (PLA₂). The treatment for snakebites is the administration of specific antivenoms, however, some of them have limitations in their neutralizing ability. A strategy proposed to improve antivenoms is to produce antibodies against the main components of the venom. The aim of this work was to produce an antivenom, using an immunization protocol including the main 3FTx and PLA₂ responsible for M. mipartitus lethality. The antibody titers were determined by ELISA in rabbits’ serum. The immunized animals elicited a response against toxins and whole venom. The Immunoglobulin G (IgGs) obtained were able to neutralize the lethal effect of their homologous toxins. A combination of antivenom from M. mipartitus with antitoxins improved their neutralizing ability. In the same way, a mixture of anti 3FTx and PLA₂ protected the mice from a 1.5 median lethal dose (LD₅₀) of M. mipartitus venom. The results showed that this might be a way to improve antibody titers specificity against the relevant toxins in M. mipartitus venom and indicated that there is a possibility to develop and use recombinant 3FTx and PLA₂ toxins as immunogens to produce antivenoms. Additionally, this represents an alternative to reduce the amount of venom used in anti-coral antivenom production. Full article

MiDCA1, a phospholipase A₂ (PLA₂) neurotoxin isolated from Micrurus dumerilii carinicauda coral snake venom, inhibited a major component of voltage-activated potassium (Kv) currents (41 ± 3% inhibition with 1 μM toxin) in mouse cultured dorsal root ganglion (DRG) neurons. In addition, the selective Kv2.1 channel blocker guangxitoxin (GxTx-1E) and MiDCA1 competitively inhibited the outward potassium current in DRG neurons. MiDCA1 (1 µM) reversibly inhibited the Kv2.1 current by 55 ± 8.9% in a Xenopus oocyte heterologous system. The toxin showed selectivity for Kv2.1 channels over all the other Kv channels tested in this study. We propose that Kv2.1 channel blockade by MiDCA1 underlies the toxin’s action on acetylcholine release at mammalian neuromuscular junctions. Full article