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A comprehensive investigation, incorporating both morphological and molecular analyses, has unveiled the existence of a hitherto unknown nematode species, Paracapillaria (Ophidiocapillaria) siamensis sp. nov., residing in the intestine of the monocled cobra, Naja kaouthia, in the central region of Thailand. This study integrates morphological characteristics, morphometric examination, scanning electron microscopy and molecular phylogenetic analysis (COI, 18S rRNA and ITS1 genes). The findings place the newly described species within the subgenus Ophidiocapillaria, elucidating its distinctive characteristics, including a frame-like proximal spicule shape, approximate lengths of 19 000 and 22 500 μm with approximate widths of 90 and 130 μm for males and females, 39‒45 stichocytes, elevated lips without protrusion, a dorsal bacillary band stripe with an irregular pattern of bacillary cells and evidence of intestinal infection. These features serve to differentiate it from other species within the same subgenus, notably Paracapillaria (Ophidiocapillaria) najae De, 1998, a species coexisting P. siamensis sp. nov. in the monocled cobra from the same locality. This study addresses the co-infection of the novel species and P. najae within the same snake host, marking the second documented instance of a paracapillariid species in the monocled cobra within the family Elapidae. The genetic characterization supports the formal recognition of P. siamensis sp. nov. as a distinct species, thereby underscoring its taxonomic differentiation within the Capillariidae family. This research identifies and characterizes the new nematode species, contributing valuable insights into the taxonomy of this nematode.

Snakebite is a neglected public health issue, with many scientific and medical issues to be solved. Cobras are among the most common venomous snakes in Myanmar and are responsible for a considerable number of severe snakebite envenoming. There are three species of cobra (Naja kaouthia, Naja mandalayensis and Ophiophagus hannah) in Myanmar. The study aims to characterize the N. kaouthia and N. mandalayensis venoms and to investigate the efficacy of anti-cobra antivenom (BPI) against the two venoms. Protein components and fibrinogenolytic activity were determined by SDS-PAGE. Enzymatic activities for PLA2, protease and acetylcholinesterase were determined by spectrophotometric method. Anticoagulant activity was determined by recalcification time of citrated human plasma. Myotoxicity, necrotizing activity, median lethal dose (LD50) and median effective dose (ED50) were determined by WHO recommended methods. The SDS-PAGE displayed the proteins and enzymes containing in two venoms were different. N. kaouthia venom exhibited more in PLA2, acetylcholinesterase, anticoagulant, fibrinogenolytic and necrotizing activities than N. mandalayensis venom. N. mandalayensis venom had more protease activity and myotoxicity than N. kaouthia venom. The median lethal dose (LD50) of N. kaouthia and N. mandalayensis venom was 4.33 μg/mouse and 5.04 μg/mouse respectively. Both venoms induced fibrinogen Aα chain degradation in 30 min (N. kaouthia) and in 6 h (N. mandalayensis). The same median effective dose (ED50) (19.56 μg/mouse) showed that anti-NK antivenom can neutralize against lethal effect of N. mandalayensis venom. It can also neutralize the protease activity, anticoagulant activity and fibrinogenolytic activity of both venoms. Immunodiffusion and immunoblotting studies showed that the antivenom recognized its homologous venom (N. kaouthia) and cross-reacted against the heterologous venom (N. mandalayensis). The anti-NK antivenom is suitable to use for N. mandalayensis bite if monospecific antivenom is not available.

The parasitic nematode Paracapillaria (Ophidiocapillaria) najae De, 1998, found in the Indian cobra Naja naja is redescribed and re-illustrated in the present study. The monocled cobra Naja kaouthia was discovered to be a new host for this parasite in central Thailand. A comprehensive description extending the morphological and molecular characteristics of the parasites is provided to aid species recognition in future studies. The morphometric characters of 41 parasites collected from 5 cobra specimens are compared with those described in the original studies. Phylogenetic analyses using mitochondrial cytochrome c oxidase subunit 1 and nuclear 18S ribosomal RNA genes were performed to provide novel information on the systematics of P. najae. Similar characteristics were observed in the examined nematode samples, despite being found in different hosts, confirming their identity as P. najae. The molecular genetic results support the species status of P. najae, indicating P. najae is well defined and separated from other related nematode species in the family Capillariidae. Morphological descriptions, genetic sequences, evolutionary relationships among capillariids and new host and distribution records of P. najae are discussed. Paracapillaria najae specimens found in the Thai cobra had some morphological variation, and sexual size dimorphism was also indicated. Paracapillaria najae was found to infect various cobra host species and appeared to be common throughout the Oriental regions, consistent with its hosts' distribution.

The impacts of commonly used and often carelessly discarded plastics are well reported in marine animals but have been poorly reported in the terrestrial animals. Here, we report for the first time two cases of dead N. kaouthia from two different habitat types due to consumption of plastic bag and fishing net. We performed a postmortem and recorded observations for both cases, confirmed the cause of death as plastic ingestion and briefly describe the clinical signs and how plastic consumption causes death in N. kaouthia. Here, we highlight how improper waste management impacts each individual's health and sometimes causes painful death in snakes. Our observation indicates that plastic ingestion in snakes is an underestimated cause of death that occurs where the snake's foraging habitat is polluted. We recommend creating awareness, proper waste management, and use of biodegradable/reusable bags can avoid wildlife mortalities in non-protected areas.

This study investigated the clinical characteristics, treatments, and outcomes of envenomation involving cobra species in Thailand (Naja kaouthia, Naja siamensis, and Naja sumatrana). Data of patients who had been bitten by a cobra or inoculated via the eyes/skin in 2018–2021 were obtained from the Ramathibodi Poison Center. There were 1045 patients admitted during the 4-year study period (bite, n = 539; ocular/dermal inoculation, n = 506). Almost all patients with ocular/dermal inoculation had eye involvement and ocular injuries, but none had neurological effects. Most of the patients bitten by a cobra had local effects (69.0%) and neurological signs and symptoms (55.7%). The median interval between the bite and the onset of neurological symptoms was 1 h (range, 10 min to 24 h). Accordingly, patients should be observed closely in hospitals for at least 24 h after a bite. Intubation with ventilator support was required in 45.5% of patients and for a median duration of 1.1 days. Antivenom was administered in 63.5% of cases. There were nine deaths, most of which resulted from severe infection. Neurological effects and intubation were significantly more common after a monocled cobra bite than after a spitting cobra bite. The administration of antivenom with good supportive care, including the appropriate management of complications, especially wound infection, might decrease fatality. [ABSTRACT FROM AUTHOR]

Snake envenoming is caused by many biological species, rather than a single infectious agent, each with a multiplicity of toxins in their venom. Hence, developing effective treatments is challenging, especially in biodiverse and biogeographically complex countries such as India. The present study represents the first genus-wide proteomics analysis of venom composition across Naja species (N. naja, N. oxiana, and N. kaouthia) found in mainland India. Venom proteomes were consistent between individuals from the same localities in terms of the toxin families present, but not in the relative abundance of those in the venom. There appears to be more compositional variation among N. naja from different locations than among N. kaouthia. Immunoblotting and in vitro neutralization assays indicated cross-reactivity with Indian polyvalent antivenom, in which antibodies raised against N. naja are present. However, we observed ineffective neutralization of PLA2 activities of N. naja venoms from locations distant from the source of immunizing venoms. Antivenom immunoprofiling by antivenomics revealed differential antigenicity of venoms from N. kaouthia and N. oxiana, and poor reactivity towards 3FTxs and PLA2s. Moreover, there was considerable variation between antivenoms from different manufacturers. These data indicate that improvements to antivenom manufacturing in India are highly desirable. [ABSTRACT FROM AUTHOR]

Simple Summary: Cobras (Naja Laurenti, 1768) are a group of well-known highly venomous snakes, which cause numerous cases of snakebites every year, especially in South Asia and Southern China. Taxonomic framework is essential for the medical treatment of snake bites and accurate antivenin development. However, the taxonomy of Asian cobras is still puzzling, especially for the widespread species Monocled Cobra (N. kaouthia Lesson, 1831). This study provided new materials and understanding for the taxonomy of this species by combining mitochondrial phylogenetic analysis and morphological comparisons based on samples from a vast area in Asia. The results showed that the Chinese population of N. kaouthia represents a new species. This study also provided new data for N. atra and designated a neotype for it. Furthermore, the subspecies N. naja polyocellata was resurrected and recognized as a full species, N. polyocellatacomb. nov., and the subspecies N. sumatrana miolepis was also resurrected. This study highlighted the necessity to evaluate the effectiveness of cobra antivenin based on a comprehensive taxonomic framework. Taxonomic frameworks for medically important species such as cobras (genus Naja Laurenti, 1768; Squamata, Elapidae) are essential for the medical treatment of snake bites and accurate antivenin development. In this paper, we described the former N. kaouthia populations recorded from China as a new species and designated a neotype for N. atra-based morphological and mitochondrial phylogenetic analysis. The new species N. fuxisp. nov. was morphologically diagnosed from N. kaouthia by (1) regular single narrow crossband present on the middle and posterior parts of the dorsum (3–15, 7.9 ± 2.7, n = 32) and the dorsal surface of the tail (1–6, 4.2 ± 1.1, n = 32) of both adults and juveniles, buff-colored with dark fringes on both edges, vs. South Asian populations (n = 39) and Southeast Asian populations (n = 35) without cross bands, with irregular cross bands or multiple light-colored crossbands pairs, or densely woven lines; (2) small scales between the posterior chin shields, usually three (40%) or two (37%), rarely four (13%), or one (10%) (n = 30) vs. mostly one (81%) and rarely two (19%) (n = 28); (3) ventrals 179–205 (195.4 ± 6.7, n = 33) vs. South Asian populations 179–199 (188.7 ± 5.9, n = 12); Southeast Asian populations 168–186 (177.8 ± 4.9, n = 18). Phylogenetically, the new species forms an independent sister clade to the clade including N. atra, N. kaouthia, N. oxiana and N. sagittifera. Furthermore, the subspecies N. naja polyocellata should be resurrected and recognized as a full species, N. polyocellatacomb. nov., and the subspecies N. sumatrana miolepis should be resurrected. [ABSTRACT FROM AUTHOR]

This study investigated the clinical characteristics, treatments, and outcomes of envenomation involving cobra species in Thailand (Naja kaouthia, Naja siamensis, and Naja sumatrana). Data of patients who had been bitten by a cobra or inoculated via the eyes/skin in 2018–2021 were obtained from the Ramathibodi Poison Center. There were 1045 patients admitted during the 4-year study period (bite, n = 539; ocular/dermal inoculation, n = 506). Almost all patients with ocular/dermal inoculation had eye involvement and ocular injuries, but none had neurological effects. Most of the patients bitten by a cobra had local effects (69.0%) and neurological signs and symptoms (55.7%). The median interval between the bite and the onset of neurological symptoms was 1 h (range, 10 min to 24 h). Accordingly, patients should be observed closely in hospitals for at least 24 h after a bite. Intubation with ventilator support was required in 45.5% of patients and for a median duration of 1.1 days. Antivenom was administered in 63.5% of cases. There were nine deaths, most of which resulted from severe infection. Neurological effects and intubation were significantly more common after a monocled cobra bite than after a spitting cobra bite. The administration of antivenom with good supportive care, including the appropriate management of complications, especially wound infection, might decrease fatality.

Introduction: Snake venom is a combination of various proteins and peptides that cause diverse biological effects on multiple organ systems. In elapid venom, three-finger toxins are the most abundant type of toxin. Although toxins share similarities in their structure, they are known for their capability to cause a myriad of toxic actions such as neurotoxicity, cardiotoxicity, and cytotoxicity. Unfortunately, many of these toxins are not fully characterized especially on their binding affinity and selectivity towards receptors and their effect to the organ system. Materials and method: Therefore, this work was conducted to compare the binding properties of selected three-finger toxins (3FTxs) from cobras (Naja sumatrana and Naja kaouthia) and mangrove catsnake (Boiga dendrophila) towards human and bird nicotinic acetylcholine receptors (?3?2, ?4?2, ?7) using computational approaches. Results: The results show that all toxins bind to the orthosteric site, which is located outside the extracellular domain of ? subunit for all receptors in both species. Interaction between receptors and toxins occurs by the formation of hydrogen bond, ionic bond, and hydrophobic contact with important residues involved in their binding pocket. Conclusion: Based on the data, the toxins showed different binding affinities towards nicotinic acetylcholine receptors in different species. Differences in the binding affinity towards different species could have a significant impact on the functional characterization of venom caused by these toxins and toxins with nearly similar sequences.

Each year, thousands of people fall victim to envenomings caused by cobras. These incidents often result in death due to paralysis caused by α‐neurotoxins from the three‐finger toxin (3FTx) family, which are abundant in elapid venoms. Due to their small size, 3FTxs are among the snake toxins that are most poorly neutralized by current antivenoms, which are based on polyclonal antibodies of equine or ovine origin. While antivenoms have saved countless lives since their development in the late 18th century, an opportunity now exists to improve snakebite envenoming therapy via the application of new biotechnological methods, particularly by developing monoclonal antibodies against poorly neutralized α‐neurotoxins. Here, we describe the use of phage‐displayed synthetic antibody libraries and the development and characterization of six synthetic antibodies built on a human IgG framework and developed against α‐cobratoxin – the most abundant long‐chain α‐neurotoxin from Naja kaouthia venom. The synthetic antibodies exhibited sub‐nanomolar affinities to α‐cobratoxin and neutralized the curare‐mimetic effect of the toxin in vitro. These results demonstrate that phage display technology based on synthetic repertoires can be used to rapidly develop human antibodies with drug‐grade potencies as inhibitors of venom toxins. [ABSTRACT FROM AUTHOR]

Taxonomic frameworks for medically important species such as cobras (genus Naja Laurenti, 1768; Squamata, Elapidae) are essential for the medical treatment of snake bites and accurate antivenin development. In this paper, we described the former N. kaouthia populations recorded from China as a new species and designated a neotype for N. atra-based morphological and mitochondrial phylogenetic analysis. The new species N. fuxisp. nov. was morphologically diagnosed from N. kaouthia by (1) regular single narrow crossband present on the middle and posterior parts of the dorsum (3–15, 7.9 ± 2.7, n = 32) and the dorsal surface of the tail (1–6, 4.2 ± 1.1, n = 32) of both adults and juveniles, buff-colored with dark fringes on both edges, vs. South Asian populations (n = 39) and Southeast Asian populations (n = 35) without cross bands, with irregular cross bands or multiple light-colored crossbands pairs, or densely woven lines; (2) small scales between the posterior chin shields, usually three (40%) or two (37%), rarely four (13%), or one (10%) (n = 30) vs. mostly one (81%) and rarely two (19%) (n = 28); (3) ventrals 179–205 (195.4 ± 6.7, n = 33) vs. South Asian populations 179–199 (188.7 ± 5.9, n = 12); Southeast Asian populations 168–186 (177.8 ± 4.9, n = 18). Phylogenetically, the new species forms an independent sister clade to the clade including N. atra, N. kaouthia, N. oxiana and N. sagittifera. Furthermore, the subspecies N. naja polyocellata should be resurrected and recognized as a full species, N. polyocellatacomb. nov., and the subspecies N. sumatrana miolepis should be resurrected.

Snakebite is a neglected public health issue, with many scientific and medical issues to be solved. Cobras are among the most common venomous snakes in Myanmar and are responsible for a considerable number of severe snakebite envenoming. There are three species of cobra ( Naja kaouthia , Naja mandalayensis and Ophiophagus hannah ) in Myanmar. The study aims to characterize the N. kaouthia and N. mandalayensis venoms and to investigate the efficacy of anti-cobra antivenom (BPI) against the two venoms. Protein components and fibrinogenolytic activity were determined by SDS-PAGE. Enzymatic activities for PLA 2 , protease and acetylcholinesterase were determined by spectrophotometric method. Anticoagulant activity was determined by recalcification time of citrated human plasma. Myotoxicity, necrotizing activity, median lethal dose (LD 50 ) and median effective dose (ED 50 ) were determined by WHO recommended methods. The SDS-PAGE displayed the proteins and enzymes containing in two venoms were different. N. kaouthia venom exhibited more in PLA 2 , acetylcholinesterase, anticoagulant, fibrinogenolytic and necrotizing activities than N. mandalayensis venom. N. mandalayensis venom had more protease activity and myotoxicity than N. kaouthia venom. The median lethal dose (LD 50 ) of N. kaouthia and N. mandalayensis venom was 4.33 μg/mouse and 5.04 μg/mouse respectively. Both venoms induced fibrinogen Aα chain degradation in 30 min ( N. kaouthia ) and in 6 h ( N. mandalayensis ). The same median effective dose (ED 50 ) (19.56 μg/mouse) showed that anti-NK antivenom can neutralize against lethal effect of N. mandalayensis venom. It can also neutralize the protease activity, anticoagulant activity and fibrinogenolytic activity of both venoms. Immunodiffusion and immunoblotting studies showed that the antivenom recognized its homologous venom ( N. kaouthia ) and cross-reacted against the heterologous venom ( N. mandalayensis ). The anti-NK antivenom is suitable to use for N. mandalayensis bite if monospecific antivenom is not available., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Mya Nila Win reports financial support was provided by 10.13039/100009647Ministry of Health, Myanmar., (© 2024 Published by Elsevier Ltd.)

Snakebite envenoming is a medical emergency requiring urgent and specific treatment. Unfortunately, snakebite diagnostics are scarce, time-consuming and lacking specificity. Hence, this study aimed to develop a simple, quick and specific snakebite diagnostic assay using animal antibodies. Anti-venom horse immunoglobulin G (IgG) and chicken immunoglobulin Y (IgY) were produced against the venoms of four major medically important snake species in Southeast Asia, i.e., the Monocled Cobra (Naja kaouthia), Malayan Krait (Bungarus candidus), Malayan Pit Viper (Calloselasma rhodostoma), and White-lipped Green Pit Viper (Trimeresurus albolabris). Different capture:detection configurations of double-antibody sandwich enzyme-linked immunosorbent assay (ELISA) were constructed using both immunoglobulins, and the horse IgG:IgG-HRP configuration was found to be most selective and sensitive in detecting the corresponding venoms. The method was further streamlined to develop a rapid immunodetection assay, which is able to produce a visual color change within 30 min for discrimination between different snake species. The study shows it is feasible to develop a simple, quick and specific immunodiagnostic assay using horse IgG, which can be derived directly from antisera prepared for antivenom production. The proof-of-concept indicates it is a sustainable and affordable approach in keeping with on-going antivenom manufacturing activities for specific species in the region. • Anti-venom horse IgG and chicken IgY for four venomous snakes were produced. • Horse IgG:IgG-HRP configuration is selective and sensitive for venom detection. • This was modified into a rapid immunodetection assay for use in Southeast Asia. • Venom of different species were discriminated by a visual color change in 30 mins. • This is a proof-of-concept study for a simple and rapid immunodiagnostic assay. [ABSTRACT FROM AUTHOR]

A 35 year old, male patient, bitten by Naja kaouthia with mild pain was admitted in Demow Government Community Health Centre. After 90 min post bite he developed neurotoxic symptoms. As per standard protocol, the patient was treated with 25 vials of antivenom and two doses of glycopyrrolate and neostigmine. Subsequently, he was seemingly devoid of any neurotoxic symptoms and showed signs of recovery. However, after 70 h, the neurotoxic symptoms recurred, and the patient was again treated with an additional 10 vials of ASV along with one dose of glycopyrrolate and neostigmine. Subsequently, the patient recovered completely from all the other symptoms of envenomation. This is the first report of recurrence of neurotoxic symptoms in a patient envenomed by Naja kaouthia in Assam, India and supports the need for greater attention and careful documentation of management of snakebite in the region. [Display omitted] • This is the first case report of recurrent neurotoxic symptoms observed in Naja kaouthia envenomation from Assam, India. • The patient recovered on treatment with 25 vials of antivenom and 2 doses of neostigmine when admitted to the hospital. • Neurotoxic symptoms recurred 70 h post bite and the patient was given another 10 vials antivenom and 1 dose neostigmine. • The patient became stable after 30 min of second dose of antivenom and was under observation for 72 h. • He was discharged after being asymptomatic on the 6th day. [ABSTRACT FROM AUTHOR]

Each year, thousands of people fall victim to envenomings caused by cobras. These incidents often result in death due to paralysis caused by α-neurotoxins from the three-finger toxin (3FTx) family, which are abundant in elapid venoms. Due to their small size, 3FTxs are among the snake toxins that are most poorly neutralized by current antivenoms, which are based on polyclonal antibodies of equine or ovine origin. While antivenoms have saved countless lives since their development in the late 18th century, an opportunity now exists to improve snakebite envenoming therapy via the application of new biotechnological methods, particularly by developing monoclonal antibodies against poorly neutralized α-neurotoxins. Here, we describe the use of phage-displayed synthetic antibody libraries and the development and characterization of six synthetic antibodies built on a human IgG framework and developed against α-cobratoxin - the most abundant long-chain α-neurotoxin from Naja kaouthia venom. The synthetic antibodies exhibited sub-nanomolar affinities to α-cobratoxin and neutralized the curare-mimetic effect of the toxin in vitro. These results demonstrate that phage display technology based on synthetic repertoires can be used to rapidly develop human antibodies with drug-grade potencies as inhibitors of venom toxins., (© 2022 The Protein Society.)