Phage display-derived alpaca nanobodies as potential therapeutics for Naja atra snake envenomation.

Naja atra, the Chinese cobra, is a major cause of snake envenomation in Asia, causing hundreds of thousands of clinical incidents annually. The current treatment, horse serum-derived antivenom, has unpredictable side effects and presents manufacturing challenges. This study focused on developing new-generation snake venom antidotes by using microbial phage display technology to derive nanobodies from an alpaca immunized with attenuated N. atra venom. Following confirmation of the immune response in the alpaca, we amplified VHH genes from isolated peripheral blood mononuclear cells and constructed a phage display VHH library of 1.0 × 107 transformants. After four rounds of biopanning, the enriched phages exhibited increased binding activity to N. atra venom. Four nanobody clones with high binding affinities were selected: aNAH1, aNAH6, aNAH7, and aNAH9. Specificity testing against venom from various snake species, including two Southeast Asian cobra species, revealed nanobodies specific to the genus Naja. An in vivo mouse venom neutralization assay demonstrated that all nanobodies prolonged mouse survival and aNAH6 protected 66.6% of the mice from the lethal dosage. These findings highlight the potential of phage display-derived nanobodies as valuable antidotes for N. atra venom, laying the groundwork for future applications in snakebite treatment.IMPORTANCEChinese cobra venom bites present a formidable medical challenge, and current serum treatments face unresolved issues. Our research applied microbial phage display technology to obtain a new, effective, and cost-efficient treatment approach. Despite interest among scientists in utilizing this technology to screen alpaca antibodies against toxins, the available literature is limited. This study makes a significant contribution by introducing neutralizing antibodies that are specifically tailored to Chinese cobra venom. We provide a comprehensive and unbiased account of the antibody construction process, accompanied by thorough testing of various nanobodies and an assessment of cross-reactivity with diverse snake venoms. These nanobodies represent a promising avenue for targeted antivenom development that bridges microbiology and biotechnology to address critical health needs.

Tracing the footprints of MPXV in Asia: phylogenetic insights and lineage dynamics.

OBJECTIVES: The 2022 global outbreak of monkeypox virus (MPXV), previously confined to Central and West Africa, necessitates an enhanced understanding of its spread. Comprehensive genomic surveillance to understand the virus's evolution and spread is needed, particularly in Asia. METHODS: Genomic data from 169 MPXV genome sequences in Asia were analysed. Through advanced genomic sequencing of clinical samples, we analysed the distribution and mutations of MPXV lineages in Asia. RESULTS: Phylogenetic analysis revealed a distinct clustering of C.1 strains rise in Northeast Asia in 2023, while genomic examination identified specific consensus mutations like R84K, R665C and L16F in C.1 strains. The mutations, coupled with an increased rate of apolipoprotein B mRNA-editing catalytic polypeptide-like 3 motif G-to-A mutations in C.1 (OR 24.87±8.81), indicate a potential adaptation mechanism. CONCLUSIONS: Our findings underscore the need for ongoing surveillance and provide vital insights into MPXV's evolving dynamics, aiding in public health strategy formulation against this emerging infectious threat.

Characterization of CRISPR-Cas Systems in Shewanella algae and Shewanella haliotis: Insights into the Adaptation and Survival of Marine Pathogens.

CRISPR-Cas systems are adaptive immune mechanisms present in most prokaryotes that play an important role in the adaptation of bacteria and archaea to new environments. Shewanella algae is a marine zoonotic pathogen with worldwide distribution, which accounts for the majority of clinical cases of Shewanella infections. However, the characterization of Shewanella algae CRISPR-Cas systems has not been well investigated yet. Through whole genome sequence analysis, we characterized the CRISPR-Cas systems in S. algae. Our results indicate that CRISPR-Cas systems are prevalent in S. algae, with the majority of strains containing the Type I-F system. This study provides new insights into the diversity and function of CRISPR-Cas systems in S. algae and highlights their potential role in the adaptation and survival of these marine pathogens.

A Nationwide Study on the Risks of Complications and Healthcare Costs of Snakebite Envenomation in Taiwan.

In Taiwan, six medically important venomous snakes, Trimeresurus stejnegeri stejnegeri, Protobothrops mucrosquamatus, Deinagkistrodon acutus, Daboia siamensis, Naja atra, and Bungarus multicinctus, are found. However, comprehensive research on the complications and associated healthcare costs of snakebite envenomation (SBE) is lacking. We retrospectively analyzed pertinent information from the Taiwan National Health Insurance Research Database dated January 2002 to December 2014. We investigated the risk factors for complications and their impact on healthcare costs. Among the 12,542 patients with SBE, those from N. atra or B. multicinctus were more likely to experience wound infections and neurological complications than were those from T. s. stejnegeri or P. mucrosquamatus. In addition, being female, being elderly, and having a Charlson Comorbidity Index equal to or greater than 3 points were associated with an increased likelihood of wound infections and psychological complications. The annual national economic burden averaged US$1,083,624, with an average healthcare cost of US$1,129 per SBE. Snakebite envenomations from N. atra or B. multicinctus, as well as various complications, resulted in significantly higher costs. It is crucial to comprehend the risk factors for complications and their role in increasing expenses to provide insight for tailored healthcare interventions, mitigate complications, and reduce the economic burdens associated with SBEs.

Characterization of chicken-derived antibody against Alpha-Enolase of Streptococcus pneumoniae.

Streptococcus pneumoniae is a clinically relevant pathogen notorious for causing pneumonia, meningitis, and otitis media in immunocompromised patients. Currently, antibiotic therapy is the most efficient treatment for fighting pneumococcal infections. However, an arise in antimicrobial resistance in S. pneumoniae has become a serious health issue globally. To resolve the problem, alternative and cost-effective strategies, such as monoclonal antibody-based targeted therapy, are needed for combating bacterial infection. S. pneumoniae alpha-enolase (spEno1), which is thought to be a great target, is a surface protein that binds and converts human plasminogen to plasmin, leading to accelerated bacterial infections. We first purified recombinant spEno1 protein for chicken immunization to generate specific IgY antibodies. We next constructed two single-chain variable fragments (scFv) antibody libraries by phage display technology, containing 7.2 × 107 and 4.8 × 107 transformants. After bio-panning, ten scFv antibodies were obtained, and their binding activities to spEno1 were evaluated on ELISA, Western blot and IFA. The epitopes of spEno1 were identified by these scFv antibodies, which binding affinities were determined by competitive ELISA. Moreover, inhibition assay displayed that the scFv antibodies effectively inhibit the binding between spEno1 and human plasminogen. Overall, the results suggested that these scFv antibodies have the potential to serve as an immunotherapeutic drug against S. pneumoniae infections.

Thromboembolic events following a pit viper bite from Protobothrops mucrosquamatus (Taiwan Habu): A report of two cases.

Protobothrops mucrosquamatus, also known as the Taiwan Habu, is a venomous snake prevalent in Taiwan. It is accountable for most snakebites in the region. The toxin of the Taiwan Habu has significant hemorrhagic potential. However, patients bitten by this snake often suffer more local injuries than systemic ones. This report presents two cases of individuals bitten by the Taiwan Habu who subsequently experienced thromboembolism. In the first case, an 88-year-old male, bitten on his fourth toe, suffered a cerebral infarction 32 hours post-bite. In the second case, an 82-year-old female, bitten on her ankle, experienced cardiac arrest 19 hours later. Both patients promptly received antivenom and showed no signs of coagulopathy either before or after the snakebite. However, elevated coagulation factor VIII levels were observed in the first case. Our aim is to understand the mechanism behind these thromboembolic events. This report emphasizes the unusually high level of coagulation factor VIIIa and highlights the need for further investigation into the mechanisms involved. Consequently, physicians should assess the risk of thromboembolic events in snakebite patients by evaluating coagulation factors during treatment.

Bacterial community analysis identifies Klebsiella pneumoniae as a native symbiotic bacterium in the newborn Protobothrops mucrosquamatus.

BACKGROUND: The study of the native microbiome of organisms is crucial. The connection between the native microbiome and the host affects the formation of the innate immune system and the organism's growth. However, the native microbiome of newborn venomous snakes has not been reported. Therefore, we aimed to determine the oral and skin microbiomes of newborn Protobothrops mucrosquamatus. RESULTS: We performed 16 S full-length sequencing on 14 samples collected from 7 newborn P. mucrosquamatus individuals, specifically targeting their oral and skin microbiomes. In terms of the oral and skin microbiome, the main species were Klebsiella pneumoniae lineages. According to subspecies/species analysis, the proportion from highest to lowest was K. quasipneumoniae subsp. similipneumoniae, K. pneumoniae subsp. pneumoniae, and K. pneumoniae subsp. rhinoscleromatis. These three bacteria accounted for 62.5% and 85% of the skin and oral activity, respectively. The oral microbiome of newborn P. mucrosquamatus did not comprise common bacteria found in snakebite wounds or oral cultures in adult snakes. Therefore, the source of other microbiomes in the oral cavities of adult snakes may be the environment or prey. Functional Annotation of the Prokaryotic Taxa analysis showed that the skin/oral native microbiome metabolism was related to fermentation and human infection owing to the dominance of K. pneumoniae lineages. The characteristics of K. pneumoniae may impact the development of venom in venomous snakes. CONCLUSION: The results of the native microbiome in the oral cavity and skin of newborn P. mucrosquamatus demonstrated that the habitat environment and prey capture may affect the composition of bacteria in adult snakes. We hypothesized that the native microbiome influences newborn venomous snakes and that K. pneumoniae lineages related to citrate fermentation may play a role in venom growth. However, further verification of this is required.

Nationwide and long-term epidemiological research of snakebite envenomation in Taiwan during 2002-2014 based on the use of snake antivenoms: A study utilizing National Health Insurance Database.

INTRODUCTION: In Taiwan, six venomous snake species with medical importance have been found; however, long-term epidemiological data of snakebite envenomation (SBE) is lacking. This study aimed to explore the epidemiology of SBE based on the distribution and use of different antivenoms in different parts of Taiwan to facilitate the development of prevention strategies and resource allocation. METHODS AND RESULTS: This retrospective study was conducted using the Taiwan National Health Insurance Research Database from 2002 to 2014. A total of 12,542 patients were treated with antivenoms. The directly standardized cumulative incidence was 3.6 cases per 100,000 individuals based on the 2000 World Standard Population. The incidence of SBEs peaked in the summer (35.9%). The relative risk (RR) of male patients versus female patients was 2.5 (p < 0.0001). The RRs of patients aged 18-64 and ≥65 years versus those aged <18 years were 6.0 (p < 0.0001) and 14.3 (p < 0.0001), respectively. Furthermore, the RR of eastern Taiwan versus northern Taiwan was 6.8 (p < 0.0001). The RR of agricultural workers versus laborers was 5.5 (p < 0.0001). Compared with patients envenomed by Trimeresurus stejnegeri stejnegeri or Protobothrops mucrosquamatus, those envenomed by Naja atra or Bungarus multicinctus multicinctus were more likely to occur in central (adjusted odds ratio [aOR] = 2.6, p < 0.0001) or southern (aOR = 3.2, p < 0.0001) Taiwan, but less frequently among agricultural workers (aOR = 0.6, p < 0.0001). The overall case-fatality rate was 0.11%. CONCLUSIONS: Among Asian countries, Taiwan had low incidence and case-fatality rates of SBE. Risk factors included male gender, old age, summer season, being in eastern Taiwan, and being an agricultural worker. Differences of the epidemiological findings between snake species should be focused on when developing strategies for snakebite prevention.

Application of Sonographic Assessments of the Rate of Proximal Progression to Monitor Protobothrops mucrosquamatus Bite-Related Local Envenomation: A Prospective Observational Study.

Patients bitten by Protobothrops mucrosquamatus typically experience significant pain, substantial swelling, and potentially blister formation. The appropriate dosage and efficacy of FHAV for alleviating local tissue injury remain uncertain. Between 2017 and 2022, 29 snakebite patients were identified as being bitten by P. mucrosquamatus. These patients underwent point-of-care ultrasound (POCUS) assessments at hourly intervals to measure the extent of edema and evaluate the rate of proximal progression (RPP, cm/hour). Based on Blaylock's classification, seven patients (24%) were classified as Group I (minimal), while 22 (76%) were classified as Group II (mild to severe). In comparison to Group I patients, Group II patients received more FHAV (median of 9.5 vials vs. two vials, p-value < 0.0001) and experienced longer median complete remission times (10 days vs. 2 days, p-value < 0.001). We divided the Group II patients into two subgroups based on their clinical management. Clinicians opted not to administer antivenom treatment to patients in Group IIA if their RPP decelerated. In contrast, for patients in Group IIB, clinicians increased the volume of antivenom in the hope of reducing the severity of swelling or blister formation. Patients in Group IIB received a significantly higher median volume of antivenom (12 vials vs. six vials; p-value < 0.001) than those in Group IIA. However, there was no significant difference in outcomes (disposition, wound necrosis, and complete remission times) between subgroups IIA and IIB. Our study found that FHAV does not appear to prevent local tissue injuries, such as swelling progression and blister formation, immediately after administration. When administering FHAV to patients bitten by P. mucrosquamatus, the deceleration of RPP may serve as an objective parameter to help clinicians decide whether to withhold FHAV administration.

Generation and characterization of avian single chain variable fragment against human Alpha-Enolase.

Overexpression of human alpha-enolase (hEno1)has been reported in a wide range of cancers and is tightly associated with poor prognosis, making it a remarkable biomarker and therapeutic target. In this study, polyclonal yolk-immunoglobulin (IgY) antibodies purified from hEno1-immunized chickens showed a noticeable specific humoral response. Phage display technology was used to construct two antibody libraries of IgY gene-derived single-chain variable fragments (scFvs) containing 7.8 × 107 and 5.4 × 107 transformants, respectively. Phage-based ELISA indicated that specific anti-hEno1 clones were significantly enriched. The nucleotide sequences of scFv-expressing clones were determined and classified into seven groups either in the short linker or the long linker. Moreover, higher mutation rates were revealed in the CDR regions, especially in the CDR3. Three distinguish antigenic epitopes were identified on the hEno1 protein. The binding activities of selected anti-hEno1 scFv on hEno1-positive PE089 lung cancer cells were confirmed using Western blot, flow cytometry, and immunofluorescence assay. In particular, hEnS7 and hEnS8 scFv antibodies significantly suppressed the growth and migration of PE089 cells. Taken together, these chicken-derived anti-hEno1 IgY and scFv antibodies have great potential to develop diagnostic and therapeutic agents for the treatment of lung cancer patients with high expression levels of hEno1 protein.

Identification of combinatorial mutations associated with colistin resistance in Shewanella algae.

Colistin is a last-resort antibiotic used to treat infections caused by drug-resistant gram-negative bacteria. However, the genetic mechanisms underlying colistin resistance in Shewanella algae are not well understood. In this study, we sequenced and compared the genomes of 23 mcr-negative colistin-resistant and sensitive S. algae samples from various sources. We applied a computational approach to identify combinatorial mutations associated with colistin resistance. Our analysis revealed a combination of three mutations (PmrB 451, PmrE168, PmrH292) that were strongly associated with colistin resistance in S. algae. This study provides insights into the genetic mechanisms of colistin resistance in S. algae and demonstrates the utility of a computational approach for identifying epistatic interactions among mutations. Identifying the genetic mutations responsible for colistin resistance in S. algae can inform the development of new treatments or strategies to combat infections caused by this emerging pathogen.

Identification of Cutibacterium modestum in Spondylitis by Metagenomics Analysis.

BACKGROUND/AIM: Identifying pathogens with culture-negative pyogenic spondylitis is difficult. Shotgun metagenomic sequencing is an unbiased and culture-free approach in the diagnosis of infectious diseases. There are, however, a variety of contaminating factors that can confound the precision of metagenomic sequencing. CASE REPORT: In a 65-year-old man suffering from culture-negative L3-5 spondylitis, metagenomics was applied to facilitate the diagnosis. The patient underwent percutaneous endoscopic lumbar discectomy. We applied metagenomic sequencing with a robust contamination-free protocol to the bone biopsy. By comparing the abundance for each taxon between the replicates and negative controls, we reliably identified Cutibacterium modestum as having a statistically higher abundance in all replicates. The patient's antibiotic therapy was switched to penicillin and doxycycline based upon the resistome analysis; the patient fully recovered. CONCLUSION: This application of next-generation sequencing provides a new perspective in the clinical approach to spinal osteomyelitis and illustrates the potential of this technique in rapid etiological diagnosis.

Insight into the Mechanisms of Carbapenem Resistance in Klebsiella pneumoniae: A Study on IS26 Integrons, Beta-Lactamases, Porin Modifications, and Plasmidome Analysis.

The emergence of carbapenem-resistant Klebsiella pneumoniae poses a significant threat to public health. In this study, we aimed to investigate the distribution and genetic diversity of plasmids carrying beta-lactamase resistance determinants in a collection of carbapenem-resistant K. pneumoniae blood isolates. Blood isolates of carbapenem-resistant K. pneumoniae bacteremia were collected and identified. Whole-genome sequencing, assembly and analysis were performed for the prediction of antimicrobial resistance determinants. Plasmidome analysis was also performed. Our plasmidome analysis revealed two major plasmid groups, IncFII/IncR and IncC, as key players in the dissemination of carbapenem resistance among carbapenem-resistant K. pneumoniae. Notably, plasmids within the same group exhibited conservation of encapsulated genes, suggesting that these plasmid groups may serve as conservative carriers of carbapenem-resistant determinants. Additionally, we investigated the evolution and expansion of IS26 integrons in carbapenem-resistant K. pneumoniae isolates using long-read sequencing. Our findings revealed the evolution and expansion of IS26 structure, which may have contributed to the development of carbapenem resistance in these strains. Our findings indicate that IncC group plasmids are associated with the endemic occurrence of carbapenem-resistant K. pneumoniae, highlighting the need for targeted interventions to control its spread. Although our study focuses on the endemic presence of carbapenem-resistant K. pneumoniae, it is important to note that carbapenem-resistant K. pneumoniae is indeed a global problem, with cases reported in multiple regions worldwide. Further research is necessary to better understand the factors driving the worldwide dissemination of carbapenem-resistant K. pneumoniae and to develop effective strategies for its prevention and control.

Clinical predictors of early surgical intervention in patients with venomous snakebites.

BACKGROUND: Venomous snakebites induce tissue destruction and secondary infection; however, the optimal timing of surgical intervention for these complications remains unknown. This study assessed the clinical predictors of early surgical intervention in patients with snakebites. METHODS: This retrospective study included 63 patients (45 men and 18 women) with venomous snakebites. In addition to the snake species, the demographics, affected body parts, clinical characteristics, and ultrasound findings of the patients in the surgical (32 patients) and nonsurgical (31 patients) groups were analyzed and compared. RESULTS: A higher incidence of acute compartment syndrome, local ecchymosis, skin necrosis, bullae, blisters, and fever was found in the surgical group than in the nonsurgical group, and ultrasound findings of the absence of Doppler flow were more frequently noted in the surgical group than in the nonsurgical group. After adjustment using a multivariate logistic regression model, only advanced age, Naja atra bite, local ecchymosis, and bulla or blister formation remained significant factors for surgical intervention. Furthermore, comparison of the outcomes of patients who received early (≤ 24 h) and late (> 24 h) surgical intervention revealed that the duration of continuous negative pressure wound therapy (6 vs. 15 days; P = 0.006), duration of hospital stay (13 vs. 26 days; P = 0.002), and duration of outpatient follow-up (15 vs. 36 days; P < 0.001) were significantly lower in patients who received early surgical intervention. The final reconstructive surgery was simple among the patients who received surgical intervention within 24 h of being bitten (P = 0.028). CONCLUSION: In patients with snakebites, advanced age, high-risk clinical manifestations (e.g., local ecchymosis and bulla or blister formation), and Naja atra envenomation are predictors of surgical intervention within 24 h.

Correction: The development of surgical risk score and evaluation of necrotizing soft tissue infection in 161 Naja atra envenomed patients.

[This corrects the article DOI: 10.1371/journal.pntd.0010066.].

A Fatal Case of Chlorfenapyr Poisoning and the Therapeutic Implications of Serum Chlorfenapyr and Tralopyril Levels.

Chlorfenapyr is a new contact and stomach insecticide derived from natural pyrroles secreted by Streptomyces spp. It is a pro-insecticide and acts after metabolic transformation to its active metabolite tralopyril. Tralopyril is an uncoupler of oxidative phosphorylation in the mitochondria of the target insects and of experiment animals, leading to the disruption of adenosine triphosphate synthesis and death. Several fatal human poisonings had been reported and no blood chlorfenapyr or tralopyril measurements were available. The treatment remains supportive. A 32-year-old healthy man ingested 200 mL of 10% chlorfenapyr as a suicide attempt. Unfortunately, he succumbed at 157 h post-ingestion, shortly after having fever and seizures. His serum level of chlorfenapyr at 4 h post-exposure was 77.4 ng/mL, and was undetectable at 113 and 156 h, respectively. The serum levels of tralopyril were 723.6, 14,179, and 9654.2 ng/mL at 4, 113, and 156 h post-ingestion, respectively. The delay in the rise of serum tralopyril levels was noticeable, which seems to correlate with the patient's signs and symptoms. The information may have therapeutic implications in the management of this deadly poisoning.

The Bottlenecks of Preparing Virus Particles by Size Exclusion for Antibody Generation.

Enterovirus 71 (EV71) is the major etiological agent contributing to the development of hand-foot-mouth disease (HFMD). There are not any global available vaccines or antibody drugs against EV71 released yet. In this study, we perform the virus immunization in a cost-effective and convenient approach by preparing virus particles from size exclusion and immunization of chicken. Polyclonal yolk-immunoglobulin (IgY) was simply purified from egg yolk and monoclonal single-chain variable fragments (scFv) were selected via phage display technology with two scFv libraries containing 6.0 × 106 and 1.3 × 107 transformants. Specific clones were enriched after 5 rounds of bio-panning and four identical genes were classified after the sequence analysis. Moreover, the higher mutation rates were revealed in the CDR regions, especially in the CDR3. IgY showed specific binding activities to both EV71-infected and Coxsackievirus 16-infected cell lysates and high infectivity inhibitory activity of EV71. However, while IgY detected a 37 kDa protein, the selected scFv seemingly detected higher size proteins which could be cell protein instead of EV71 proteins. Despite the highly effective chicken antibody generation, the purity of virus particles prepared by size exclusion is the limitation of this study, and further characterization should be carried out rigorously.

Comparison of Protein Variation in Protobothrops mucrosquamatus Venom between Northern and Southeast Taiwan and Association with Human Envenoming Effects.

Reports of bite from Protobothrops mucrosquamatus (Pmu) are frequent in Taiwan, and its wide-spread distribution and diverse habitats drove us to investigate its envenoming effects and relevant venom variations. We used reversed-phase high-performance liquid chromatography and mass spectrometry to analyze 163 Pmu venom samples collected from northern and southeastern Taiwan. Twenty-two major protein fractions were separated and analyzed, and their contents were determined semi-quantitatively. The results showed that despite the trivial differences in the protein family, there is an existing variation in acidic phospholipases A2s, serine proteinases, metalloproteinases, C-type lectin-like proteins, and other less abundant components in the Pmu venoms. Moreover, clinical manifestations of 209 Pmu envenomed patients hospitalized in northern or southeastern Taiwan revealed significant differences in local symptoms, such as ecchymosis and blistering. The mechanism of these local effects and possibly relevant venom components were examined. Further analysis showed that certain venom components with inter-population variation might work alone or synergistically with others to aggravate the local effects. Therefore, our findings of the venom variation may help one to improve antivenom production and better understand and manage Pmu bites.

Case Report: Management of an Uncommon Crotaline Snakebite (Ovophis makazayazaya).

Ovophis makazayazaya bite is an uncommon cause of snakebite that humans may sustain as a result of the continuous overexploitation of forest habitats and excessive development in Taiwan. Although the Taiwanese government has produced four antivenoms against medically important snakebite accidents, O. makazayazaya is not among the snakes for which an antivenom has been produced. A case of O. makazayazaya snakebite on a patient's right foot, which later swelled into the hip, is reported. In vitro studies have reported that monovalent antivenoms for Gloydius brevicaudus and Trimeresurus albolabris, and polyvalent antivenom for Calloselasma rhodostoma, Daboia siamensis, and T. albolabris show reactivity toward Ovophis venoms. However, these antivenoms are unavailable in Taiwan. Thus, bivalent antivenom for Trimeresurus stejnegeri stejnegeri and Protobothrops mucrosquamatus was used, assuming similar immunoreactivity and a possible para-specific effect of green pit viper antivenom against this Ovophis venom. A favorable outcome was observed, without significant extension in prothrombin time and activated partial thromboplastin time. In addition, no systemic bleeding occurred. Nonetheless, further venom and antivenom evaluations should ascertain the efficacy of this para-specific antivenoms against this crotaline snakebite.

Uncommon defibrinogenation and coagulopathy caused by Trimeresurus stejnegeri stejnegeri envenomation in a patient with swelling above the ankle.

In Taiwan, Trimeresurus stejnegeri stejnegeri (Stejneger's Bamboo pitviper) is responsible for more than half of all venomous snakebites annually. This species often causes local envenoming characterized by tissue swelling and pain, occasional local ecchymosis, bullae and blister formation, and lymphangitis and lymphadenitis. The pathophysiology and treatment of potentially life-threatening coagulopathy and defibrinogenation induced by T. s. stejnegeri systemic envenoming have not been specifically addressed. Here, we describe the case of a man who was bitten by T. s. stejnegeri on his right first toe, which later developed into swelling above the ankle. It was found that there was severe hypofibrinogenemia, prolonged prothrombin time, and reduced activities of factors V and XI, plasminogen, and α2-antiplasmin. Even though a favorable outcome was achieved after repeatedly administering specific antivenom, fresh frozen plasma, and cryoprecipitate, probably low effectiveness of antivenom against the coagulopathy and prodigious amounts of replacement products were observed. To control coagulopathy early and avoid the needless replacement of coagulation factor, which are associated with inherent adverse reactions, more frequent serial blood assessment (e.g., every 6 h) and higher initial antivenom doses may be helpful. Knowledge of the specific coagulation factor deficiencies may improve our understanding of the relationship between hemotoxins and the resulting envenoming syndromes in this snakebite.