Tifton 68 (Cynodon nlemfuensis) is a cyanogenic forage grass that may also contribute to dietary sulfur exposure. Young Tifton 68 was introduced into a 32-animal dairy herd. Within approximately 2 days, neurological disease was recognized; eight cattle were affected and four died. Affected cattle developed visual and postural deficits, hypermetria, intention tremors, recumbency, and convulsions. The forage produced a rapid positive reaction in the qualitative sodium picrate paper test. Neuropathological examination of one cow revealed bilateral pseudolaminar cortical neuronal necrosis with selective deep gray-matter and cerebellar injury. The outbreak was strongly associated with Tifton 68, but cyanide exposure was not analytically confirmed and total sulfur exposure was not determined, leaving cyanide exposure and sulfur-associated polioencephalomalacia as competing etiological hypotheses.

Approximately 294 million people live within 10-km grid cells containing recent, georeferenced records of Nicotiana glauca, a widely naturalized poisonous plant associated with severe anabasine-mediated intoxication. Although this spatial overlap does not represent direct human exposure, it highlights the broad geographic extent of potential human-plant encounters. However, it remains unclear whether readily observable plant characteristics, such as developmental stage, leaf morphology, or seasonal condition, can reliably identify plants with consistently low foliar anabasine concentrations. We combined a field survey in three Brazilian localities and longitudinal sampling at one of these localities with comparative phylogenetic and global occurrence analyses to address this question across within-species, evolutionary and geographic scales. All 174 field and longitudinal determinations yielded non-zero estimates, despite substantial quantitative variation among localities and individuals. Within the sampled plants, neither juvenile leaf size, adult collection state nor sampled calendar month identified a condition with consistently low foliar anabasine concentrations. Across 54 Nicotiana species, foliar anabasine showed significant phylogenetic structure (Blomberg's K = 0.59-1.11; Pagel's λ = 0.86-0.93), with consistently elevated standardized scores in Nicotiana section Noctiflorae. Nicotiana glauca ranked second in the cross-study foliar consensus, behind N. noctiflora, but its geographic distribution was markedly broader: 1,243 one-degree grid cells across 66 countries, 12.8 times the occupied-cell breadth of the next most widespread high-scoring species. Together, these findings show that the toxicological significance of N. glauca arises from the convergence of persistent foliar anabasine occurrence across sampled conditions, lineage-associated high concentrations and an unusually broad global distribution, rather than from chemical constancy alone.

Snake-related injuries (SRI) in Malaysia are a medical emergency. SRI may be accompanied by wound infection requiring medical and surgical intervention. Despite its clinical relevance, local epidemiological and microbiological data remain limited in Malaysia. This was an observational analysis conducted on 72 hospitalised patients with wound infections following snake-related injuries who received consultation from the Remote Envenomation Consultancy Services (RECS). Data were collected using a standardised collection form. Among 559 hospitalised SRI cases, 72 patients (12.9%) developed wound infections. Males accounted for 70.8%, and most patients with wound infections were young adults aged 18 to 44. The most frequent symptoms were swelling (91.7%) and erythema (69.4%). SRI from Naja species were the most frequently identified cause of wound infections. Bacterial cultures were positive in 15.3% of cases, with Enterococcus species being the most frequently identified. Amoxicillin/clavulanate was the most used antibiotic. Wound debridement was performed in 27.8% of cases. Most patients were hospitalised for more than 5 days, and the most common outcome was healed with a scar (34.7%). No mortality was reported. This study emphasises the need for accurate clinical assessments to distinguish between venom-induced inflammation and subsequent bacterial infection. Although the culture-positive rate was low, the presence of pathogens such as Enterococcus species, which are often resistant to standard antibiotics, emphasises the need for cultures and sensitivity testing in snakebite-related infections. Early antivenom therapy, adequate antibiotic usage, and prompt surgical intervention, such as debridement, will improve patient outcomes. These findings provide useful local insights for clinical guidelines and for better management of wound infections following snake-related injuries in Malaysia.

Chactas exsul (Werner, 1939) is a specialized, saproxylic scorpion belonging to the diverse family Chactidae, inhabiting the humid tropical forests of Costa Rica and Panama. Characterized by robust pedipalps and a relatively small telson, C. exsul primarily relies on mechanical immobilization for prey capture, though it may utilize venom during challenging encounters. Despite its evolutionary importance, the venom of most of its members remains largely uncharacterized. In this study, we provide a comprehensive proteomic and biochemical analysis of the venom of C. exsul from the Caribbean lowlands of Costa Rica. Our results reveal a venom peptidome dominated by putative scorpine-like antimicrobial peptides, calcins, and orphan components such as La1-like peptides. Sodium channel-modulating toxins (NaTxs) and common non-buthid potassium toxins (α- and κ-KTx) were not identified. The protein fraction exhibited significant complexity, featuring metalloproteinases, serine proteinases, phospholipases A2, and two putative hyaluronidase isoforms, among others. CAP-domain secretory proteins show several variants in the venom. These findings suggest a dual-functional trophic and, probably, defensive strategy: with a peptide fraction likely targeting insect-specific K[+] and Ca[2+] channels, which could induce paralysis, while the enzymatic cocktail could facilitate toxin maturation and spreading, as well as tissue predigestion. These activities and the role of putative scorpines as antimicrobials against soilborne pathogens inhabiting humid microhabitats remain to be determined.

The venom of the slender black scorpion Centruroides nigrescens, from the State of Guerrero México, was fractionated by Sephadex G-50 gel filtration, followed by carboxymethyl cellulose ion separation and high-performance liquid chromatography, permitting to obtain two new peptides toxic to arthropods. The estimate LD50 of the soluble venom for the insect Acheta domesticus was 11.1 μg/g body weight, and for the arthropod Armadillidium vulgare was 61.1 μg body weight . The amino acid sequence of toxin Cnige1 (toxic to A. domesticus and A. vulgare) contains 65 amino acids, with a molecular mass of 7273.37 mass units, whereas toxin Cnige2, toxic to A. domesticus, contains 68 amino acids, with a molecular mass of 7548.81 units. Both peptides are well packed, containing 8 cysteines, which in the native venoms are forming 4 disulfide bridges each. The amino acid sequences found, for both novel toxins, shows some similarities to other known scorpion arthropod toxins. This venom is not toxic to mammalians, using mice as model, but contains many peptides as shown by mass spectrometry, for which the full primary structure and function are not known.

Snake venom is a complex and dynamic ecological trait, with high potential for intraspecific variation. In this study, the venom composition of the Iberian adder (Vipera seoanei) from the Peneda Mountains of northern Portugal was investigated to explore whether venom varies with body size and sex. Venom proteomes from six individuals representing juvenile, subadult, and adult males and females were characterised using LC-MS/MS, while individual variation was assessed from SDS-PAGE profiles of 18 snakes. LC-MS/MS identified 144 proteins, dominated by phospholipases A2 (PLA2), snake venom serine proteases (svSP), and C-type lectin-related proteins (CTL). Descriptive comparisons revealed contrasting individual profiles, particularly between the juvenile male, characterised by high svSP and svMP abundance, and the juvenile female, characterised by high PLA2 abundance. Subadult proteomes were dominated by PLA2, whereas adults had high PLA2 and svSP abundance. However, PERMANOVA of the SDS-PAGE profiles detected no significant effects of ontogenetic class or sex on venom composition, suggesting that the observed proteomic patterns should be interpreted with caution. This study provides an initial characterisation of ontogenetic and sex-related venom variation in V. seoanei, highlighting the need for larger studies that combine individually resolved quantitative proteomics with dietary, ecological, and functional data.

Paediatric snakebites can present substantial diagnostic and therapeutic uncertainty, particularly in rural hospitals where access to specialist toxicology expertise may be limited. Emergency expert advice services may support frontline clinicians, but their utilisation and perceived value remain poorly understood. We conducted a qualitative study among 42 physicians working in four hospitals serving snakebite-endemic regions of Sri Lanka. Eight focus group discussions were conducted at Teaching Hospital Batticaloa, District General Hospital Polonnaruwa, District General Hospital Trincomalee and Teaching Hospital Kurunegala. A semi-structured guide explored circumstances prompting consultation, clinical decision-making, reasons for non-utilisation, perceived benefits, barriers to access and priorities for service improvement. Discussions were audio-recorded, transcribed and analysed thematically using Braun and Clarke's framework. Six interrelated themes were identified. Expert advice was primarily sought in the context of clinical uncertainty, unidentified snakes, severe envenoming, antivenom decisions and complications. Advice was perceived to support critical management decisions, provide reassurance and increase clinicians' confidence, with potential benefits for patient management and avoidance of unnecessary treatment. Utilisation was moderated by the availability of consultants and senior colleagues, with external advice less frequently sought for straightforward cases or when local expertise was readily accessible. Important barriers included limited availability, particularly at night, busy telephone lines, connectivity problems, delayed responses and difficulty identifying the correct contact number. Participants advocated 24-h and island-wide access, improved communication pathways, regular training, point-of-care educational resources and digital platforms. Expert advice services provide an important layer of specialist decision support for physicians managing paediatric snakebites. Improving accessibility while integrating expert consultation with training, clinical guidance and digital decision-support tools may strengthen snakebite care in rural settings.

Snakebite envenomation remains a significant global health concern, with viperid snakes responsible for substantial mortality and disability. In Iran, the genus Macrovipera is of considerable medical importance. Macrovipera razii is an endemic Iranian species distributed across central and southern regions of the country; however, detailed clinical reports of envenomation by this species remain scarce. We report two cases of M. razii envenomation from Iran. The first case involved a 36-year-old male who sustained a bite to the middle finger in Nazmabad, Arak, Markazi Province, Iran, in 2017. He was admitted to hospital approximately 15 min after the bite and received six vials of polyvalent antivenom. Progressive local tissue injury developed, followed by severe necrosis of the affected finger, resulting in permanent deformity and severe functional impairment. The second case involved a 37-year-old male who sustained a bite to the dorsal aspect of the right hand in Sirjan, Kerman Province, in 2024. He received one vial of polyvalent antivenom during ambulance transport, followed by five additional vials after hospital admission and two further vials approximately 2 h later, resulting in a total of eight vials during the initial treatment period. He developed severe and progressive hand edema with clinical features concerning for acute compartment syndrome and underwent emergency fasciotomy, followed by delayed wound closure, prolonged hospitalization, and persistent partial functional impairment. Both cases demonstrated severe local tissue injury following M. razii envenomation. The clinical manifestations were broadly consistent with severe local effects reported following envenomation by other medically important viperid species. However, the limited number of documented cases precludes conclusions regarding the typical clinical course, frequency, or severity of M. razii envenomation. These cases underscore the need for further clinical and experimental investigation of M. razii envenomation and its management. Clinical observations alone cannot establish antivenom efficacy or failure, particularly in the absence of venom-antivenom cross-reactivity and functional neutralization data. Further studies, including comprehensive venom characterization and functional venom-antivenom neutralization assays, are warranted to clarify antivenom recognition and coverage and to inform future antivenom development.

Ricin toxin (RT) is a highly potent plant-derived toxin that causes severe cellular injury and inflammatory responses, yet effective therapeutic interventions remain limited. Autophagy is a conserved stress-response pathway that maintains intracellular homeostasis and modulates innate immune signaling. However, whether autophagy contributes to macrophage adaptation during RT intoxication and how this process is regulated remain incompletely understood. In this study, we investigated RT-induced autophagic responses and their relationship with TLR4/MyD88 signaling in RAW264.7 macrophages using transmission electron microscopy, immunofluorescence staining, tandem mRFP-eGFP-LC3 reporter analysis, Western blotting, and Atg5 knockdown/overexpression approaches. RT treatment induced autophagic vacuole formation, increased LC3 puncta, and elevated the expression of LC3-II, Atg5, Beclin-1, and p62, with LC3 puncta peaking at 2 h after stimulation. Tandem LC3 reporter analysis further supported activation of autophagic flux during the early response to RT. Pharmacological inhibition of autophagy with 3-methyladenine reduced LC3-II accumulation and aggravated RT-associated loss of cell viability, suggesting a cytoprotective role of autophagy. Mechanistically, RT increased p38 MAPK phosphorylation, and inhibition of p38 MAPK activity with SB203580 attenuated RT-induced LC3 puncta formation, whereas JNK inhibition showed no obvious effect under the same conditions. Furthermore, Atg5 knockdown enhanced RT-induced TLR4 and MyD88 protein expression and IL-1β secretion, whereas Atg5 overexpression suppressed these responses; TRIF expression was not markedly altered. These findings suggest that RT triggers an early p38 MAPK-associated autophagic response in macrophages and that Atg5-dependent autophagy restrains TLR4/MyD88-associated innate immune signaling. This study provides mechanistic insight into the adaptive cellular response to RT exposure and identifies autophagy as a potential modulatory pathway in RT-induced macrophage injury.

Scorpion envenomation is a medical emergency that can produce severe cardiovascular complications. Centruroides tecomanus, an endemic scorpion species from western Mexico, is medically relevant, although its early cardiac effects remain poorly characterized. This study evaluated the initial cardiotoxic effects of C. tecomanus venom in Wistar rats using serial electrocardiographic recordings, algorithm-based ECG signal processing, histopathology, and serum biochemical markers. Fourteen rats were allocated to control and venom-treated groups (n = 7 per group). The experimental group received an intraperitoneal sublethal dose equivalent to one-third of the LD50. One-minute ECG recordings obtained at 5-min intervals during the first hour were analyzed using an enhanced computational algorithm for noise reduction, R-peak detection, R-R interval analysis, and characterization of cardiac conduction. Venom-treated animals showed a biphasic chronotropic response, with early tachycardia followed by progressive bradycardia, together with altered impulse generation, migratory atrial pacemaker activity, and atrioventricular conduction abnormalities. Histopathological analysis revealed increased inter-fiber separation and eosinophilic changes in the ventricular myocardium, without overt necrosis, whereas pulmonary architecture remained largely preserved. CK, CK-MB, and AST showed no significant changes at 8 h after envenomation, while LDH decreased significantly. These findings characterize the early temporal progression of C. tecomanus venom-associated cardiotoxicity, beginning with rhythm and atrioventricular conduction abnormalities and accompanied by mild myocardial inter-fiber separation, but without overt necrosis or a conventional serum enzyme pattern of myocardial injury.

Tephrosia noctiflora is an infesting weed species recorded in agricultural crops and pastures in Alagoas, Northeast Brazil, associated with economic losses in local cattle ranching due to literature reports of management difficulties and potential toxicity from putative rotenoids. This study evaluated the ecophysiology and seed resilience under abiotic stresses to estimate its persistence in pasture areas. Five temperature regimes were evaluated (20, 25, 30, 35, and alternating 20 to 30 °C) under light and dark conditions. At 30 °C, intact and acid-scarified seeds were subjected to thermal stress (80 to 240 °C for 5 min), aluminum toxicity (0.0 to 6.0 mmolc.dm[-3]), and osmotic stress (-0.3 to -1.5 MPa). Germination peaked at 20 °C, 30 °C, and under the alternating regime in the presence of light, indicating preferential positive photoblastism, while declining markedly at 35 °C. Thermal stress from 120 °C resulted in complete embryo mortality, whereas exposure to 80 °C promoted physical dormancy release. Aluminum reduced germination starting at 1.5 mmolc.dm[-3], with low germination rates observed at higher concentrations; however, seeds retained viability, demonstrating tolerance to the acidic and aluminum-rich soils typical of Alagoas and the Northeast region. Osmotic stress progressively restricted germination, reaching complete inhibition at -1.5 MPa and inducing root plasticity under moderate water deficit conditions. Seeds of T. noctiflora exhibit high physiological resilience against chemical and hydric limitations, contributing to its colonization success and the persistence of toxicological risks to grazing livestock.

Identifying the biting snake supports envenomation surveillance, yet molecular identification from bite-site swabs is limited because snake DNA is a minor component relative to human DNA. In two clinical specimens where conventional PCR failed, a semi-nested protocol targeting cytb recovered species-level identification of Gloydius blomhoffii and the non-venomous Elaphe climacophora, corroborated by phylogenetic placement. These preliminary observations suggest semi-nested amplification may aid molecular snakebite surveillance and warrant larger validation.