Search Results (7)

Envenomation caused by venomous animals may trigger significant local complications such as pain, edema, localized hemorrhage, and tissue necrosis, in addition to complications such as dermonecrosis, myonecrosis, and even amputations. This systematic review aims to evaluate scientific evidence on therapies used to target local effects caused by envenomation. The PubMed, MEDLINE, and LILACS databases were used to perform a literature search on the topic. The review was based on studies that cited procedures performed on local injuries following envenomation with the aim of being an adjuvant therapeutic strategy. The literature regarding local treatments used following envenomation reports the use of several alternative methods and/or therapies. The venomous animals found in the search were snakes (82.05%), insects (2.56%), spiders (2.56%), scorpions (2.56%), and others (jellyfish, centipede, sea urchin—10.26%). In regard to the treatments, the use of tourniquets, corticosteroids, antihistamines, and cryotherapy is questionable, as well as the use of plants and oils. Low-intensity lasers stand out as a possible therapeutic tool for these injuries. Local complications can progress to serious conditions and may result in physical disabilities and sequelae. This study compiled information on adjuvant therapeutic measures and underscores the importance of more robust scientific evidence for recommendations that act on local effects together with the antivenom. Full article

Sea snake venom is extremely toxic, and it can induce severe respiratory failure and cause high mortality. The most effective first aid treatment for sea snake bites is to inject antivenom as soon as possible. However, in China, there are only four types of terrestrial snake antivenoms, none of which are effective in the treatment of sea snake bites. In order to develop an antivenom for the dominant species of sea snakes in Chinese seas, Hydrophis curtus venom (HcuV) was chosen as the antigen to immunize horses. From immune plasma, a high-titer Hydrophis curtus antivenom (HcuAV) was prepared. In vitro assessment showed that HcuAV had a cross-neutralizing capacity against HcuV and Hydrophis cyanocinctus venom (HcyV). In vivo assessment indicated that HcuAV injection could significantly improve the survival rates of the HcuV and HcyV envenomated mice (0% to 100% and 87.5%, respectively) when it was injected at a sufficient amount within the shortest possible time. In addition, HcuAV could also effectively alleviate multiple organ injuries caused by HcuV. These results provide experimental support for the future clinical application of HcuAV. Full article

Envenomation resulted from sea snake bite is a highly lethal health hazard in Southeast Asia. Although commonly caused by sea snakes of Hydrophiinae, each species is evolutionarily distinct and thus, unveiling the toxin gene diversity within individual species is important. Applying next-generation sequencing, this study investigated the venom-gland transcriptome of Hydrophis curtus (spine-bellied sea snake) from Penang, West Malaysia. The transcriptome was de novo assembled, followed by gene annotation and sequence analyses. Transcripts with toxin annotation were only 96 in number but highly expressed, constituting 48.18% of total FPKM in the overall transcriptome. Of the 21 toxin families, three-finger toxins (3FTX) were the most abundantly expressed and functionally diverse, followed by phospholipases A₂. Lh_FTX001 (short neurotoxin) and Lh_FTX013 (long neurotoxin) were the most dominant 3FTXs expressed, consistent with the pathophysiology of envenomation. Lh_FTX001 and Lh_FTX013 were variable in amino acid compositions and predicted epitopes, while Lh_FTX001 showed high sequence similarity with the short neurotoxin from Hydrophis schistosus, supporting cross-neutralization effect of Sea Snake Antivenom. Other toxins of low gene expression, for example, snake venom metalloproteinases and L-amino acid oxidases not commonly studied in sea snake venom were also identified, enriching the knowledgebase of sea snake toxins for future study. Full article

The venom proteome of Hydrophis curtus (synonym: Lapemis hardwickii) from Penang, Malaysia was investigated with nano-electrospray ionization-liquid chromatography tandem mass spectrometry (ESI-LCMS/MS) of the reverse-phase high-performance liquid chromatography (HPLC) venom fractions. Thirty distinct protein forms were identified as toxins from ten families. The three major protein families were phospholipase A₂ (PLA₂, 62.0% of total venom proteins), three-finger toxin (3FTX, 26.33%) and cysteine-rich secretory protein (CRiSP, 9.00%). PLA₂ comprises diverse homologues (11 forms), predominantly the acidic subtypes (48.26%). 3FTX composed of one short alpha-neurotoxin (SNTX, 22.89%) and four long alpha-neurotoxins (LNTX, 3.44%). Both SNTX and LNTX were lethal in mice (intravenous LD₅₀ = 0.10 and 0.24 μg/g, respectively) but the PLA₂ were non-lethal (LD₅₀ >1 μg/g). The more abundant and toxic SNTX appeared to be the main driver of venom lethality (holovenom LD₅₀ = 0.20 μg/g). The heterologous Sea Snake Antivenom (SSAV, Australia) effectively cross-neutralized the venom (normalized potency = 9.35 mg venom neutralized per g antivenom) and the two neurotoxins in vivo, with the LNTX being neutralized more effectively (normalized potency = 3.5 mg toxin/g antivenom) than SNTX (normalized potency = 1.57 mg/g). SSAV immunorecognition was strong toward PLA₂ but moderate-to-weak toward the alpha-neurotoxins, indicating that neutralization of the alpha-neurotoxins should be further improved. Full article

The spine-bellied sea snake (Hydrophis curtus) is known to cause human deaths, yet its venom composition has not yet been proteomically characterised. An in-depth proteomic analysis was performed on H. curtus venom from two different seasons, January and June, corresponding to adults and subadults, respectively. Venoms from adult and subadult H. curtus individuals were compared using reversed-phase high-performance liquid chromatography (RP-HPLC), matrix-assisted laser desorption ionisation-time of flight (MALDI-TOF) mass spectrometry and liquid chromatography electrospray ionisation mass spectrometry (LC-ESI-MS) to detect intraspecific variation, and the molecular weight data obtained with ESI-MS were used to assess toxin diversity. RP-HPLC and LC-ESI-MS/MS were used to characterise the venom proteome and estimate the relative abundances of protein families present. The most abundant protein family in January and June venoms is phospholipase A₂ (PLA₂: January 66.7%; June 54.5%), followed by three-finger toxins (3FTx: January 30.4%; June 40.4%) and a minor component of cysteine-rich secretory proteins (CRISP: January 2.5%; June 5%). Trace amounts of snake venom metalloproteinases (SVMP), C-type lectins and housekeeping and regulatory proteins were also found. Although the complexity of the venom is low by number of families present, each family contained a more diverse set of isoforms than previously reported, a finding that may have implications for the development of next-generation sea snake antivenoms. Intraspecific variability was shown to be minor with one obvious exception of a 14,157-Da protein that was present in some January (adult) venoms, but not at all in June (subadult) venoms. There is also a greater abundance of short-chain neurotoxins in June (subadult) venom compared with January (adult) venom. These differences potentially indicate the presence of seasonal, ontogenetic or sexual variation in H. curtus venom. Full article

Antivenom neutralization against cobra venoms is generally low in potency, presumably due to poor toxin-specific immunoreactivity. This study aimed to investigate the effectiveness of two elapid antivenoms to neutralize the principal toxins purified from the venoms of the Thai monocled cobra (Naja kaouthia, Nk-T) and the Malaysian beaked sea snake (Hydrophis schistosus, Hs-M). In mice, N. kaouthia Monovalent Antivenom (NKMAV) neutralization against Nk-T long neurotoxin (LNTX) and cytotoxin was moderate (potency of 2.89–6.44 mg toxin/g antivenom protein) but poor against the short neurotoxin (SNTX) (1.33 mg/g). Its cross-neutralization against Hs-M LNTX of Hs-M is compatible (0.18 mg/g) but much weaker against Hs-M SNTX (0.22 mg/g). Using CSL (Seqirus Limited) Sea Snake Antivenom (SSAV), we observed consistently weak neutralization of antivenom against SNTX of both species, suggesting that this is the limiting factor on the potency of antivenom neutralization against venoms containing SNTX. Nevertheless, SSAV outperformed NKMAV in neutralizing SNTXs of both species (0.61–2.49 mg/g). The superior efficacy of SSAV against SNTX is probably partly attributable to the high abundance of SNTX in sea snake venom used as immunogen in SSAV production. The findings indicate that improving the potency of cobra antivenom may be possible with a proper immunogen formulation that seeks to overcome the limitation on SNTX immunoreactivity. Full article

Sea snake envenomation is a serious occupational hazard in tropical waters. In Malaysia, the beaked sea snake (Hydrophis schistosus, formerly known as Enhydrina schistosa) and the spine-bellied sea snake (Hydrophis curtus, formerly known as Lapemis curtus or Lapemis hardwickii) are two commonly encountered species. Australian CSL sea snake antivenom is the definitive treatment for sea snake envenomation; it is unfortunately extremely costly locally and is not widely available or adequately stocked in local hospitals. This study investigated the cross-neutralizing potential of three regionally produced anti-cobra antivenoms against the venoms of Malaysian H. schistosus and H. curtus. All three antivenoms conferred paraspecific protection from sea snake venom lethality in mice, with potency increasing in the following order: Taiwan bivalent antivenom < Thai monocled cobra monovalent antivenom < Thai neuro polyvalent antivenom (NPAV). NPAV demonstrated cross-neutralizing potencies of 0.4 mg/vial for H. schistosus venom and 0.8 mg/vial for H. curtus, which translates to a dose of less than 20 vials of NPAV to neutralize an average amount of sea snake venom per bite (inferred from venom milking). The cross-neutralization activity was supported by ELISA cross-reactivity between NPAV and the venoms of H. schistosus (58.4%) and H. curtus (70.4%). These findings revealed the potential of NPAV as a second-line treatment for sea snake envenomation in the region. Further profiling of the cross-neutralization activity should address the antivenomic basis using purified toxin-based assays. Full article