-
Toxins Oct 2020The scorpion and brown spider represent a public health problem in Asia and America, respectively. Although distinct, these organisms contain similar toxins... (Comparative Study)
Comparative Study
The scorpion and brown spider represent a public health problem in Asia and America, respectively. Although distinct, these organisms contain similar toxins responsible for the principal clinical signs of envenomation. To better understand the properties of these toxins, we designed a study to compare recombinant Heminecrolysin (rHNC) and rLiD1, the major phospholipase D toxins of scorpion and spider venom, respectively. Using a competitive ELISA and a hemolytic inhibition test, we come to spot a cross reaction between scorpion and spider venoms along with an epitopic similarity between rHNC and rLiD1 associated with neutralizing antibodies. Results show that the ability of the rHNC to hydrolyze lysophosphatidylcholine (LPC) is equivalent to that of rLiD1 to hydrolyze sphingomyelin and vice-versa. rHNC exclusively catalyze transphosphatidylation of LPC producing cyclic phosphatidic acid (cPA). The in-silico analysis of hydrogen bonds between LPC and toxins provides a possible explanation for the higher transphosphatidylase activity of rHNC. Interestingly, for the first time, we reveal that lysophosphatidic acid (LPA) can be a substrate for both enzymes using cellular and enzymatic assays. The finding of the usage of LPA as a substrate as well as the formation of cPA as an end product could shed more light on the molecular basis of envenomation as well as on loxoscelism.
Topics: Animals; Antivenins; Brown Recluse Spider; Cross Reactions; Epitopes; Hemolysis; Insect Bites and Stings; Lysophosphatidylcholines; Necrosis; Phospholipase D; Phosphoric Diester Hydrolases; Scorpion Venoms; Scorpions; Skin; Sphingomyelins; Spider Venoms; Substrate Specificity
PubMed: 33019554
DOI: 10.3390/toxins12100631 -
Microbiology Spectrum Jun 2022Animal venoms are considered sterile sources of antimicrobial compounds with strong membrane-disrupting activity against multidrug-resistant bacteria. However, venomous...
Animal venoms are considered sterile sources of antimicrobial compounds with strong membrane-disrupting activity against multidrug-resistant bacteria. However, venomous bite wound infections are common in developing nations. Investigating the envenomation organ and venom microbiota of five snake and two spider species, we observed venom community structures that depend on the host venomous animal species and evidenced recovery of viable microorganisms from black-necked spitting cobra (Naja nigricollis) and Indian ornamental tarantula (Poecilotheria regalis) venoms. Among the bacterial isolates recovered from , we identified two venom-resistant, novel sequence types of Enterococcus faecalis whose genomes feature 16 virulence genes, indicating infectious potential, and 45 additional genes, nearly half of which improve bacterial membrane integrity. Our findings challenge the dogma of venom sterility and indicate an increased primary infection risk in the clinical management of venomous animal bite wounds. Notwithstanding their 3 to 5% mortality, the 2.7 million envenomation-related injuries occurring annually-predominantly across Africa, Asia, and Latin America-are also major causes of morbidity. Venom toxin-damaged tissue will develop infections in some 75% of envenomation victims, with E. faecalis being a common culprit of disease; however, such infections are generally considered to be independent of envenomation. Here, we provide evidence on venom microbiota across snakes and arachnida and report on the convergent evolution mechanisms that can facilitate adaptation to black-necked cobra venom in two independent E. faecalis strains, easily misidentified by biochemical diagnostics. Therefore, since inoculation with viable and virulence gene-harboring bacteria can occur during envenomation, acute infection risk management following envenomation is warranted, particularly for immunocompromised and malnourished victims in resource-limited settings. These results shed light on how bacteria evolve for survival in one of the most extreme environments on Earth and how venomous bites must be also treated for infections.
Topics: Animals; Arachnida; Asia; Bacteria; Snakes; Venoms
PubMed: 35604233
DOI: 10.1128/spectrum.02408-21 -
Case Reports in Cardiology 2015Clinical manifestation of black widow spider bite is variable and occasionally leads to death in rural areas. Cases of myocarditis and pericarditis after black widow...
Clinical manifestation of black widow spider bite is variable and occasionally leads to death in rural areas. Cases of myocarditis and pericarditis after black widow spider bite are rare and the associated prognostic significance is unknown. Kounis syndrome has been defined as an acute coronary syndrome in the setting of allergic or hypersensitivity and anaphylactic or anaphylactoid insults that manifests as vasospastic angina or acute myocardial infarction or stent thrombosis. Allergic myocarditis is caused by myocardial inflammation triggered by infectious pathogens, toxic, ischemic, or mechanical injuries, such as drug-related inflammation and other immune reactions. A 15-year-old child was admitted to the emergency department with pulmonary edema after spider bite. ST segment depression on ECG, elevated cardiac enzymes and global left ventricular hypokinesia (with ejection fraction of 22%), and local pericardial effusion findings confirmed the diagnosis of myopericarditis. After heart failure and pulmonary edema oriented medical therapy, clinical status improved. Patient showed a progressive improvement and LV functions returned to normal on the sixth day. Myopericarditis complicating spider bite is rare and sometimes fatal. The mechanism is not clearly known. Alpha-latrotoxin of the black widow spider is mostly convicted in these cases. But allergy or hypersensitivity may play a role in myocardial damage.
PubMed: 26509087
DOI: 10.1155/2015/768089 -
Revista Medica de Chile May 2021Loxoscelism is an important public health problem in Chile and South America, due to the higher rate of cutaneous-visceral involvement. The diagnosis of loxoscelism is...
BACKGROUND
Loxoscelism is an important public health problem in Chile and South America, due to the higher rate of cutaneous-visceral involvement. The diagnosis of loxoscelism is mostly clinical without established diagnostic criteria. There is little evidence to support any treatment used in this condition.
AIM
To characterize the clinical features and epidemiology of loxoscelism among patients consulting at the Emergency and Dermatology Services of a clinical hospital between 2013 and 2017.
MATERIAL AND METHODS
Review of medical records of patients registered in the electronic clinical record system with a confirmed diagnosis of loxoscelism. Epidemiological, clinical, laboratory tests and treatment variables were analyzed.
RESULTS
We reviewed data from 200 patients. Ninety-four percent presented cutaneous loxoscelism and 5.5% cutaneous-visceral loxoscelism. Systemic symptoms were present in 73% of patients with cutaneous-visceral loxoscelism. Patients who developed systemic symptoms had an 18 times higher risk of developing cutaneous-visceral loxoscelism. Laboratory abnormalities were more common in patients with cutaneous-visceral loxoscelism. Not all patients with hematuria had cutaneous-visceral loxoscelism. Most patients required analgesia. Anti-loxosceles serum was not used in any patient.
CONCLUSIONS
Many questions remain to be answered regarding the diagnosis and treatment of the disease. Studies are required to validate diagnostic criteria for loxoscelism, predictors for visceral involvement and response to treatment.
Topics: Animals; Chile; Humans; Pain; Spider Bites; Spider Venoms; Spiders
PubMed: 34751320
DOI: 10.4067/s0034-98872021000500682 -
PeerJ 2020The is a species of theraphosid spider from China. Its large size and charming appearance make this species a popular pet. According to a previous study, theraphosid...
The is a species of theraphosid spider from China. Its large size and charming appearance make this species a popular pet. According to a previous study, theraphosid spider bites can induce pain, erythema, and edema in humans and can present more severely in domestic animals. The pathological consequences of envenomation by remain unclear. In this study, we investigated the effects and mechanisms of envenomation in mice. We showed that the venom induced slight swelling, intense inflammatory response, and increased the microvascular density in mice skin. Moreover, we found that 50 µg/ml of the spider's venom induced IL-1β expression in both HaCaT cells and fibroblast cells, but repressed CXCL10 expression in fibroblasts. The venom significantly induced cell senescence and repressed cell proliferation and migration in both HaCaT cells and fibroblast cells. Finally, we examined the expression of Nav channel in HaCaT and fibroblast cells and found that venom effectively inhibited Na currents in HaCaT cells. Our study calls for further investigation of the pathological consequences and potential mechanisms of envenomation. This information might assist in the development of suitable therapy.
PubMed: 31942253
DOI: 10.7717/peerj.8264 -
Cardiology and Therapy Dec 2020The black widow spider (BWS) is a venomous spider whose bite can cause various clinical conditions that range from local damage to serious systemic complications,...
The black widow spider (BWS) is a venomous spider whose bite can cause various clinical conditions that range from local damage to serious systemic complications, including death. Cases of myocarditis following a BWS bite are rare but they can be fatal on occasion. However, the prognostic significance of the bite and presentation of myocarditis is unknown. Our case involved a 50-year-old man who presented with myocarditis after being bitten by a BWS and subsequently admitted to the intensive care unit for cardiac monitoring. During the hospital stay, he showed worsening signs on both the electrocardiographic and echocardiographic evaluations despite therapeutic success. Subsequent cardiac magnetic resonance and coronary angiography investigations showed no significant alterations; blood and instrumental test results slowly improved, and the patient was discharged home after 12 days of hospitalization without complications. This case illustrates that acute myocarditis, although an infrequent complication of BWS bite, has the potential to be lethal. The correct diagnosis, which is not always easy to formulate, is important to identify those patients who can benefit from careful monitoring and specific therapies aimed at reducing the risk of life.
PubMed: 32462634
DOI: 10.1007/s40119-020-00178-3 -
Journal of Pediatric Hematology/oncology Jan 2019Brown recluse spider bites can cause local and systemic signs, including rash, dermonecrosis, edema, hemolysis, and acute kidney failure. These are mostly attributed to... (Clinical Trial)
Clinical Trial
Brown recluse spider bites can cause local and systemic signs, including rash, dermonecrosis, edema, hemolysis, and acute kidney failure. These are mostly attributed to sphingomyelinase D, the main toxin. To evaluate the severity of the disease in pediatric patients with and without neutropenia, we retrospectively reviewed records of patients treated at St. Jude Children's Research Hospital between 1970 and 2015 and identified 19 patients who met the inclusion criteria. Variables of interest included the type of underlying illness, presence of neutropenia, number of days of hospitalization, disease signs and outcome of the bite, and treatments administered. We used descriptive statistics to summarize the manifestations and severity of spider bites in patients with and without neutropenia. Six patients experienced pain from the bite, 11 had erythema, 7 developed edema, and 5 had fever. The response to spider bites in neutropenic patients was no milder than that in non-neutropenic individuals. Six patients developed systemic complications. Compared with non-neutropenic patients, neutropenic patients had antibiotics prescribed more often and experienced longer hospital stays. Spider bites do not seem to have a different clinical course in neutropenic patients. Therefore, a conservative approach may be best for these patients, with close monitoring and local wound care.
Topics: Adolescent; Adult; Anti-Bacterial Agents; Child; Child, Preschool; Female; Humans; Male; Neoplasms; Neutropenia; Retrospective Studies; Severity of Illness Index; Spider Bites
PubMed: 30028826
DOI: 10.1097/MPH.0000000000001253 -
La Clinica Terapeutica Jul 2021Spider bites are often overestimated because there are no specific clinical or histopathological aspects that characterize them, and skin lesions that resemble a spider...
INTRODUCTION
Spider bites are often overestimated because there are no specific clinical or histopathological aspects that characterize them, and skin lesions that resemble a spider bite are often wrongly considered to be a "true spider bite". However, even in case of a true spider bite, it is almost impossible to confirm the biting species, since very often neither physicians nor patients are trained in spider identification.
OBJECTIVE
The aim of this report is to provide clinicians with a rapid and simple recognition of the few Italian medically relevant spiders, in order to take relative medical measures in case of spider bites.
MATERIALS AND METHODS
We defined spiders of considerable medical relevance the ones that cause local symptoms with possible systemic involvement, while we defined spiders with mild medical relevance the ones whose bite is not a medical emergency but is particularly painful or can cause lasting symptoms. We focused on the identification of the four spider taxa of major clinical interest through a brief descriptive, photographic and graphic guide, in association to dermatological manifestations.
RESULTS
Spiders of considerable medical relevance are Loxosceles rufescens and Latrodectus tredecimguttatus, while spiders of less severe medical relevance are Steatoda paykulliana, S. nobilis, S. grossa, Cheiracanthium punctorium, Amblyocarenum spp. and Macrothele calpeiana (the presence of the latter in Italy is only accidental and very sporadic). The only species capable of causing necrosis is Loxo-sceles rufescens, while Latrodectus tredecimguttatus can cause more systemic symptoms.
DISCUSSION AND CONCLUSION
With the aim of promoting a first and rapid recognition of the species, we performed a morphological usable aspect for an initial and quick recognition according to an identification key.
Topics: Animals; Diagnostic Techniques and Procedures; Female; Humans; Italy; Male; Photography; Spider Bites; Spiders
PubMed: 34247217
DOI: 10.7417/CT.2021.2338 -
Frontiers in Molecular Biosciences 2021Brown spider (genus ) venoms are mainly composed of protein toxins used for predation and defense. Bites of these spiders most commonly produce a local dermonecrotic... (Review)
Review
Brown spider (genus ) venoms are mainly composed of protein toxins used for predation and defense. Bites of these spiders most commonly produce a local dermonecrotic lesion with gravitational spread, edema and hemorrhage, which together are defined as cutaneous loxoscelism. Systemic loxoscelism, such as hematological abnormalities and renal injury, are less frequent but more lethal. Some venom toxins have already been isolated and extensively studied, such as phospholipases D (PLDs), which have been recombinantly expressed and were proven to reproduce toxic activities associated to the whole venom. PLDs have a notable potential to be engineered and converted in non-toxic antigens to produce a new generation of antivenoms or vaccines. PLDs also can serve as tools to discover inhibitors to be used as therapeutic agents. Other toxins have been identified and functionally characterized, such as hyaluronidases, allergen factor, serpin, TCTP and knottins (ICK peptides). All these toxins were produced as recombinant molecules and are biologically active molecules that can be used as tools for the potential development of chemical candidates to tackle many medical and biological threats, acting, for instance, as antitumoral, insecticides, analgesic, antigens for allergy tests and biochemical reagents for cell studies. In addition, these recombinant toxins may be useful to develop a rational therapy for loxoscelism. This review summarizes the main candidates for the development of drugs and biotechnological inputs that have been described in Brown spider venoms.
PubMed: 34222343
DOI: 10.3389/fmolb.2021.706704 -
Scientific Data Mar 2022Mass media plays an important role in the construction and circulation of risk perception associated with animals. Widely feared groups such as spiders frequently end up...
Mass media plays an important role in the construction and circulation of risk perception associated with animals. Widely feared groups such as spiders frequently end up in the spotlight of traditional and social media. We compiled an expert-curated global database on the online newspaper coverage of human-spider encounters over the past ten years (2010-2020). This database includes information about the location of each human-spider encounter reported in the news article and a quantitative characterisation of the content-location, presence of photographs of spiders and bites, number and type of errors, consultation of experts, and a subjective assessment of sensationalism. In total, we collected 5348 unique news articles from 81 countries in 40 languages. The database refers to 211 identified and unidentified spider species and 2644 unique human-spider encounters (1121 bites and 147 as deadly bites). To facilitate data reuse, we explain the main caveats that need to be made when analysing this database and discuss research ideas and questions that can be explored with it.
Topics: Animals; Databases, Factual; Humans; Language; Newspapers as Topic; Spider Bites; Spider Venoms; Spiders
PubMed: 35347145
DOI: 10.1038/s41597-022-01197-6