PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Ant Venoms”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources

Proteomic analysis of Myrmecia pilosula (jack jumper) ant venom.

Ant sting allergy in Australia is predominantly due to the Myrmecia pilosula species complex. Gel separation of M. pilosula venom is necessary so that the allergenic importance of each component can be defined by western blotting. However, previous PAGE methods produced suboptimal resolution and the components of each band were not precisely defined. Venom was resolved in both non-reduced and reduced form by one-dimensional acid urea PAGE, SDS-PAGE and two-dimensional acid urea-SDS PAGE. Resolved peptides were extracted and analysed by HPLC-MS. Acid urea PAGE and acid urea-SDS PAGE proved more effective than SDS-PAGE for resolution of peptides smaller than 10 kDa. All of the major peptides previously observed in M. pilosula venom were observed in gel resolved venom. Venom was found to primarily consist of peptides with molecular weight <10 kDa, most of which contain disulfide bridges. SDS-PAGE of non-reduced venom clearly defined six higher molecular weight proteins between 26 and 90 kDa. An 8546 Da dimer named pilosulin 5 was observed, but pilosulin 4, a peptide recently proposed to be present in venom was not. A variant of pilosulin 4 here named pilosulin 4.1a, existing as an 8198 Da dimer, was observed and has been characterised.

Animals↗

Fire ant venom hypersensitivity. I. Comparison of fire ant venom and whole body extract in the diagnosis of fire ant allergy.

Levels of IgE antibody to fire ant whole body extract (FA-WBE) and fire ant venom (FAV) were evaluated in 60 patients with clinical histories of fire ant sting hypersensitivity and 11 frequently stung individuals without significant clinical reactivity to fire ant. An overlap of levels of IgE antibody to FA-WBE and FAV was seen between groups of patients with increasingly severe clinical reactivity; however, the group mean IgE antibody level of patients without significant clinical reactivity differed markedly from the group means of patients with more severe clinical reactivity (p less than 0.001). In 31 patients a good correlation (r = 0.6935) was found comparing FA-WBE IgE antibody level with FA-WBE skin tests, and in 26 patients a good correlation (r = 0.8564) was obtained comparing FAV IgE antibody levels with FAV skin tests. An excellent Spearman rank correlation coefficient (r = 0.9197) was found on comparison of FAV and FA-WBE IgE antibody levels in 71 individuals. Cross-reactivity of FAV and FA-WBE was demonstrated by the ability of these reagents to competitively inhibit the binding of IgE antibody to solid-phase FA-WBE and FAV in the radioallergosorbent test (RAST). From these results we conclude that FAV and FA-WBE both contain relevant allergens important in fire ant-allergic individuals and that skin tests and RAST are both valid as diagnostic tests for fire ant allergy. Finally, there is a good correlation between RAST and skin tests using FA-WBE or FAV as test reagents, since these reagents are highly cross-reactive as demonstrated by their ability to inhibit each other in the RAST.

Adolescent↗

In vivo and in vitro comparison of fire ant venom and fire ant whole body extract.

Thirty-four patients with a history of immediate hypersensitivity to the sting of the imported fire ant were evaluated in a study designed to compare the diagnostic usefulness of fire ant whole body extract (WBE) preparations with that of fire ant venom (IFAV). Ninety-one percent (31/34) of the hypersensitive patients skin tested with IFAV at a maximal concentration of 1:5 X 10(3), v/v, demonstrated a wheal equal to or greater than the histamine control. Fifty-three percent (18/34) of the group were skin test positive to a WBE preparation. When the criteria for a positive skin test were relaxed, 82% of the hypersensitive group could be identified with the IFAWBE. A comparison of skin test results in sensitive patients revealed variability in the sensitivity of the WBE preparations utilized in the study. Leukocyte histamine release demonstrated a dose-response release of histamine with both IFAV and SIWBEa preparations. Specific venom antisera produced in rabbits identified a precipitin line of common identity in a gel-diffusion system containing IFAWBE and IFAV. This finding was verified by the competitive inhibition of IFAWBE with IFAV in a solid-phase radioimmunoassay system. Fire ant WBEs contain venom constituents and are effective diagnostic agents in up to 82% of patients with hypersensitivity to the sting of the imported fire ant. Marked variability in the responsiveness of sensitive patients to different WBE preparations mandates standardization of these diagnostic preparations.

Adolescent↗

Some enzymic activities of two Australian ant venoms: a jumper ant Myrmecia pilosula and a bulldog ant Myrmecia pyriformis.

Venoms from two related Australian ants, a jumper ant (Myrmecia pilosula) and a bulldog ant (Myrmecia pyriformis), were quantitatively analysed for the following enzymic activities: phospholipase A2, phospholipase B, phospholipase C, hyaluronidase, esterase, acid phosphatase, alkaline phosphatase and phosphodiesterase. Both venoms contained phospholipase A2, phospholipase B, hyaluronidase, acid phosphatase and alkaline phosphatase activities. Myrmecia pyriformis venom had significantly greater phospholipase B, acid phosphatase and alkaline phosphatase activities than Myrmecia pilosula venom. No detectable quantities of phospholipase C, esterase or phosphodiesterase activities were found in either venom.

Acid Phosphatase↗

Safety and efficacy of fire ant venom in the diagnosis of fire ant allergy.

Thirty-three adult patients who had had systemic allergic reactions to fire ant stings and 33 insect-nonallergic control subjects were skin tested with single lots of Solenopsis invicta (Sol i) fire ant venom (IFAV) and two commercially available imported fire ant whole body extracts (IFA WBEs). All three extracts were analyzed for protein concentration. Sol i II and Sol i III concentrations were each assayed by means of two ELISAs with complementary monoclonal antibodies, one species specific and one cross-reactive. Radioallergosorbent test (RAST) to IFAV and both IFA WBEs was performed on sera from all study subjects. Both IFA WBEs contained high concentrations of fire ant body proteins. Sol i II and III concentrations each varied twofold between the two IFA WBE preparations. Patients were generally more reactive to IFAV than IFA WBE by skin testing and RAST. IFAV RAST appeared to be a more sensitive assay than IFA WBE RAST. No adverse reactions occurred to skin testing with IFAV, but intradermal testing with higher concentrations of IFA WBE caused delayed large local reactions in 16 of 30 (53%) control subjects. These reactions were attributed to the large amounts of extraneous body proteins in IFA WBE. These results (1) demonstrate that skin testing with IFAV is safe, (2) indicate that IFAV is more potent than IFA WBE, and (3) suggest that IFAV may be the superior reagent for diagnosis of fire ant allergy.

Adult↗

Allergens in Hymenoptera venom. XXI. Cross-reactivity and multiple reactivity between fire ant venom and bee and wasp venoms.

The relationships between fire ant venom and bee and wasp venoms were explored by studying sera from five groups of subjects. Group 1 included adults not allergic to any venoms and who were not exposed to fire ants. Group 2 included adults with fire ant exposure who were not allergic to venoms. Group 3 included patients with recent systemic reactions to fire ant venom. Group 4 included patients allergic to bee and vespid venoms with no fire ant exposure. Last, group 5 included patients allergic to bee and vespid venoms with fire ant exposure. None of the serum samples from group 1 was RAST reactive to fire ant venom, but 24% of those from group 2 were fire ant positive, as were 100% of those from group 3, 51% of those from group 4, and 87% of those from group 5. The RAST-positive patients in groups 2 and 5 were also skin test positive. RAST inhibition studies demonstrated cross-reactivity in some cases and multiple reactivity in others. The serum samples were further investigated via nondenaturing electrophoretic immunoblot studies and RAST with highly purified allergens. Serum samples from group 4 reacted to a single band on immunoblots and with only one of the four purified allergens from fire ant venom (Solenopsis invicta I, or Sol i I). Serum samples from groups 2, 3, and 5 showed various patterns of allergen reactivity. All serum samples from patients allergic to fire ant venom who also reacted to bee and/or vespid venoms by RAST contained IgE antibodies binding to Sol i I.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Allergens in Hymenoptera venom XXIV: the amino acid sequences of imported fire ant venom allergens Sol i II, Sol i III, and Sol i IV.

The most common cause of insect venom allergy in the Southeastern United States is the imported fire ant. The allergens are among the most potent known, with nanogram doses causing sensitization and provoking anaphylaxis. The complete amino acid sequences of imported fire ant venom allergens, Sol i II, III, and IV, were determined by solid-phase protein sequencing of overlapping peptide fragments. Sol i II has a single sequence of 119 amino acids and a molecular weight of 13,217. It has seven cysteine residues, and in its native form is a disulfide-linked dimer. The highly purified molecule does not have phospholipase activity and is not structurally related to phospholipases or other known proteins. Sol i IV has 117 amino acids, for a molecular weight of 13,340. It has six cysteines and is a monomer. Its sequence is 35% identical to Sol i II, but it is not significantly related to other proteins. The Sol i IV sequence showed two amino acid variations. Sol i III was found to consist of 212 amino acids of molecular weight 24,040 in good agreement with 26,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The sequence contained eight cysteine residues and was found to be 44% to 50% identical to five vespid venom antigen 5 molecules. IgE antibodies against Sol i III do not exhibit strong cross-reactivity with vespid antigen 5s. The sequence similarity is consistent with other data, suggesting that ants are related to wasps of the superfamily Vespoidea.(ABSTRACT TRUNCATED AT 250 WORDS)

Allergens↗

Isolation of a hemolytic component of fire ant venom.

A crystalline hemolytic principle, shown to be a constituent of fire ant venom and having the properties of an amine, was isolated from crude extracts of whole ants. The chromatographic procedure of isolation is described, and a preliminary report is given about some properties of the substance.

Amines↗

Prevention of anaphylaxis with ant venom immunotherapy.

PURPOSE OF REVIEW: Worldwide, eight genera of ants have been associated with sting allergy. Until recently only whole ant body extracts have been used for immunotherapy. The purpose of this review is to examine recent advances in the understanding of ant venom allergy and treatment using venom immunotherapy. RECENT FINDINGS: Public health problems due to severe ant sting anaphylaxis are not confined to the imported fire ant of North America. Pachycondyla sennaarensis (samsum ant), Pachycondyla chinensis, and Myrmecia pilosula (jack jumper ant) also appear to pose notable threats. The risk to humans from a particular species probably depends on complex interactions between likelihood of human contact, insect aggression, efficiency of the venom delivery apparatus, and venom allergenicity. The highest population prevalence of clinical ant sting allergy so far (3.0%) was reported from south-eastern Australia, due mainly to M. pilosula. Prospective follow-up of untreated people suggests that those older than 30 years with a history of severe reactions (respiratory compromise or hypotension) will benefit most from venom immunotherapy. Whereas the efficacy of ant whole body extract immunotherapy remains to be proven, ant venom immunotherapy has been demonstrated to reduce the risk of systemic reactions to M. pilosula from 72% to 3%. Although a simple method of venom extraction has been developed, small market size means that the treatment may never become widely available. SUMMARY: Ant venom immunotherapy is feasible and highly efficacious. However, the limited geographical distribution of each species presents a major challenge to making venom extracts available for clinical use.

Anaphylaxis↗

Hypersensitivity to fire ant venom.

LEARNING OBJECTIVES: Reading this article will reinforce the reader's knowledge of the taxonomy, origin, and distribution of fire ants and will increase his ability to diagnose and manage reactions caused by the two imported species, Solenopsis invicta and richteri. This review will also enhance the reader's knowledge of the available diagnostic methods and therapeutic measures, including the role of fire ant venom versus whole body extract in the management of fire ant allergy. DATA SOURCES: Information for this review was obtained primarily from abstracts and articles written by investigators recognized for their expertise in fire ant venom research. STUDY SELECTION: References were selected based on their clinical applicability and relevance to the epidemiology and pathophysiology of imported fire ant hypersensitivity. CONCLUSIONS: The imported fire ant represents a significant health hazard for persons living in fire ant endemic areas in the southern United States. Sting reactions range from local pustules and large, late-phase responses to life-threatening anaphylaxis. Fire ant allergen-specific immunotherapy can reduce the risk of subsequent systemic reactions. Four important Sol i venom allergens have been isolated and characterized. Clinical studies have been designed to compare the safety and efficacy of fire ant venom with whole body extract for diagnosis and treatment of fire ant allergy.

Animals↗

A method for the manufacture of single barrel liquid ion-selective microelectrodes: an in situ study of ant venom pH.

A method for the manufacture of single barrel ion-sensitive microelectrodes, employing liquid ion-selective sensors, is described in detail. This method had proven reliable and repeatable for the manufacture of pH-sensitive microelectrodes using a liquid proton carrier. It is believed that this method has advantages over other published methods since it allows direct visualization and control of major steps during electrode fabrication and overcomes several problems often encountered using more conventional methods. Microelectrodes fabricated using this technique have been used to measure the in situ pH of venom from two myrmicine ants, Tetramorium caespitum (L.) and Myrmica ruginodis (N.).

Animals↗

Sol i 1, the phospholipase allergen of imported fire ant venom.

BACKGROUND: Sol i 1, the venom phospholipase of imported fire ant venom is an important allergen and exhibits some cross-reactivity with IgE antibodies from patients sensitized to other Hymenoptera venoms. OBJECTIVE: To determine the primary structure of Sol i 1 and evaluate the roles of protein and carbohydrate epitopes in its cross-reactivity. METHODS: Sol i 1 was purified from venom, proteolytic peptides prepared and amino acid sequences obtained. The cDNA for Sol i 1 was cloned, sequenced, and compared with sequences of other wasp venom phospholipases. The role of carbohydrate epitopes in the cross-reactivity with other Hymenoptera venoms was studied by RAST inhibition. RESULTS: The sequence identified Sol i 1 as a lipase of the GX class, lipoprotein lipase superfamily, pancreatic lipase homologous family and RP2 subgroup phospholipases as are the vespid venom phospholipases. The 148 residues identified by amino acid sequencing represent about 48% of the translated cDNA sequence. Sol i 1 was 31-32% identical to yellow jacket phospholipases. The identical regions of sequence were clustered in the domain which forms the serine hydrolase active site. Mannosylated N-glycans could completely inhibit binding of IgE from honeybee venom sensitized patients to Sol i 1. Inhibition by glycan of IgE binding from yellow jacket venom sensitized patients was low or absent for three of eight sera and substantial, but not complete for five sera. CONCLUSIONS: Sol i 1 is related to wasp venom phospholipases. Cross-reactivity with honeybee venom is caused by carbohydrate, whereas cross-reactivity with yellow jacket venom involves reactivity with both carbohydrate determinants of hyaluronidase and high molecular weight proteins and phospholipase protein determinants.

Allergens↗

Effects of fire ant venom alkaloids on platelet and neutrophil function.

About 95% of venom of the imported fire ant Solenopsis invicta is composed of dialkyl piperidines. These alkaloids produce a distinct pustule at the site of injection. The formation of this pustule may involve the activation of platelets and neutrophils. The purpose of this paper was to characterize the effects of fire ant venom alkaloids (FAVA) on certain physiological and biochemical functions of human platelets and neutrophils. In platelets, FAVA caused a rise in intracellular [Ca2+], secretion of dense granules as measured by ATP release, and aggregation as measured by light transmission through a suspension of platelets. Aggregation response was less complete with FAVA than with thrombin or PAF. However, secretion response was greater with FAVA than thrombin. One of our most significant findings was that pretreatment of platelets with subthreshold concentrations of FAVA produced enhanced PAF-induced increase in [Ca2+]cyt, suggesting that synergism between the two agonists might play an important role in the physiological response to FAVA. In neutrophils, FAVA produced a rise in intracellular [Ca2+] and aggregation, although the responses were more moderate than those observed in platelets. These results suggest that FAVA activation of platelets and neutrophils may occur in vivo as a response to stings by red fire ants.

Adenosine Triphosphate↗

Slow inhibition of Na+ current in crayfish axons by 2-(1non-8enyl)-5-(1non-8enyl)pyrrolidine (Pyr9), a synthetic derivative of an ant venom alkaloid

2,5-Dialkylpyrrolidines present in the venom of ants from the genus Monomorium are natural insecticides causing a flaccid paralysis. The mechanism of action of 2-(1non-8enyl)-5-(1non-8enyl)pyrrolidine (Pyr9), a synthetic derivative of 2,5-dialkylpyrrolidines, has been investigated in vitro on preparations of the ventral nerve cord of the crayfish Procambarus clarkii. Our results clearly indicate that Pyr9 blocks spike conduction without affecting the resting potential. Voltage-clamp experiments carried out on axons demonstrate that this blockade is due to a dual expression of Na+ current inhibition: a tonic inhibition developing slowly (90 % of inhibition within 20 min for a Pyr9 concentration of 50 &micro;mol l-1) and independently of stimulation, and a phasic inhibition developing during repetitive stimulation (5 Hz), the accumulation kinetics of which is 0.072 pulse-1 at 5 Hz, according to the Courtney model. These findings suggest that tonic and phasic inhibition are due to different mechanisms. In addition, Pyr9 induces a shift of the Na+ inactivation curve towards more hyperpolarized potentials, which is in agreement with a higher affinity of Pyr9 for inactivated than for resting Na+ channels.

Journal Article↗

Allergens in Hymenoptera venom. XVII. Allergenic components of Solenopsis invicta (imported fire ant) venom.

Pure venom from Solenopsis invicta was collected by having the insects sting into a capillary tube. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) demonstrated that three major protein bands were present in the venom. A prototype commercial extract was compared and found to contain the three major venom proteins and additional components as well as high potency and specificity by RAST. Immunoblot studies were performed with sera from allergic individuals with blots prepared from denatured SDS-PAGE gels and from two types of nondenaturing gels. The nondenaturing systems demonstrated the presence of two major allergens and three other allergens, each reacting with a third of the sera. Three of the allergens detected in SDS-PAGE blots were of identical mobility to the three major proteins in the pure venom sample. IgE binding to the SDS-PAGE blots was significantly less than that to nondenaturing blots, suggesting that much of the allergenic activity is conformation dependent.

Allergens↗

Prevalence, severity, and natural history of jack jumper ant venom allergy in Tasmania.

BACKGROUND: The jack jumper ant (Myrmecia pilosula) is responsible for greater than 90% of Australian ant venom allergy. However, deaths have only been recorded in the island of Tasmania. OBJECTIVES: We sought to determine the prevalence, clinical features, natural history, and predictors of severity of M pilosula sting allergy in Tasmania. METHODS: We performed a random telephone survey supported by serum venom-specific IgE analysis, review of emergency department presentations, and follow-up of allergic volunteers. RESULTS: M pilosula, honeybee (Apis mellifera), and yellow jacket wasp (Vespula germanica) sting allergy prevalences were 2.7%, 1.4%, and 0.6% compared with annual sting exposure rates of 12%, 7%, and 2%, respectively. Similarly, emergency department presentations with anaphylaxis to M pilosula were double those for honeybee. M pilosula allergy prevalence increased with age of 35 years or greater (odds ratio [OR], 2.4) and bee sting allergy (OR, 16.9). Patients 35 years of age or older had a greater risk of hypotensive reactions (OR, 2.9). Mueller reaction grades correlated well with adrenaline use. During follow-up, 79 (70%) of 113 jack jumper stings caused anaphylaxis. Prior worst reaction severity predicted the likelihood and severity of follow-up reactions; only 3 subjects had more severe reactions. Venom-specific IgE levels and other clinical features, including comorbidities, were not predictive of severity. CONCLUSIONS: Sting allergy prevalence is determined by age and exposure rate. M pilosula sting exposure in Tasmania is excessive compared with that found in mainland Australia, and there is a high systemic reaction risk in allergic people on re-sting. Prior worst reaction severity (Mueller grade) and age predict reaction severity and might be used to guide management.

Allergens↗

The effects of a partially purified fraction of an ant venom in rheumatoid arthritis.

A partially purified extract of an ant venom from the South American tree ant Pseudomyrmex sp. was tested in a double-blind, controlled study of patients with rheumatoid arthritis. Venom treated patients demonstrated an improvement in global efficacy and a decrease in the number of tender/painful joints and swollen joints. Swollen joint index improved in 60% of venom treated patients. Other parameters did not demonstrate significant change. Reduction of joint swelling was followed by symptomatic improvement that was sometimes delayed by weeks. Reactions were limited to erythema at the injection site (all patients), local pruritus (two-thirds of the patients), and fever with malaise (one-third of the patients). Further study of this venom in rheumatoid arthritis appears warranted in view of its apparent favorable efficacy-to-toxicity ratio.

Adult↗

Imported fire ant hypersensitivity. Studies of human reactions to fire ant venom.

It is now apparent that venom and venom components of the Hymenoptera superfamilies of Apida (honeybee) and Vespida (wasps, yellow jackets, and hornets) are becoming increasingly important in the diagnosis and treatment of hypersensitivity reactions. Stings from fire ants (superfamily Formicidae, family Myrmicinae) have also been recognized as causes of systemic reactions in man. Fire ant venom is unique in its composition, consisting mainly of alkaloids in aqueous suspension with only trace amounts of protein. This study compares the skin reactivity of fire ant venom and synthesized alkaloid components with the whole body extract (WBE) of fire ants and other Hymenoptera. The venom as well as the WBE of fire ants was found useful for skin test diagnosis of sensitive individuals. There appear to be cross-reactive or shared antigens between fire ant venom, WBE, and WBE of other Hymenoptera. Successful passive transfer of skin reactivity to nonsensitive individuals was accomplished with sera from sensitive individuals. Loss of this passive transfer by heating sera at 56 degrees C for 4 hr is evidence in favor of IgE mediating the positive skin test to the venom.

Animals↗