i205 Bumble bee | Thermo Fisher Scientific (2024)

Bumble bees (Bombus terrestris; Bombus pennsylvanicus) are insects of the Apidae family, found in many countries. There are many different bumble bee species, which vary in phenotype. The venom injected by the bee’s stinger is the cause of hypersensitivity and allergic reactions. A number of bumble bee venom allergens have been described.

Allergic reactions to bumble bee venom present with symptoms ranging from localized to systemic, including severe anaphylaxis. Cross reactivity with other bumble bee and honey bee venom allergens may occur.

Nature

Bumble bees (Bombus terrestris and the American bumble bee, Bombus pennsylvanicus) are insects of the order Hymenoptera, family Apidae and share some similarities with honey bees (1). Bumble bees are larger and have more hair (pile) than honey bees; the queen bumble bee is 30–35 mm, while the workers range in size between 8–22 mm. Male bees tend to look like a large worker. B. terrestris bumble bees are typically black, with an orange/ochre band across the thorax and another across the abdomen. The tip of the abdomen is usually whitish in color. Although this phenotype is characteristic of B. terrestris, other Bombus species present a high variety of coloring and sizes; genetic analysis is usually required to distinguish species (2).

Bumble bees are social insects, forming a colony at the end of winter when a hibernating queen emerges and starts a new colony nest. Throughout the warmer seasons, the queen will rear workers to maintain the colony and produce new queens and males which will hibernate in autumn. Most species of bumble bees have an annual life cycle (2).

Bumble bees are important players in temperate ecosystems because of their pollinator activity. There are around 250 species of bumble bees, with many subspecies, contributing to great phenotypical variety (2).

Bumble bees tend prefer warm to temperate climates and hibernate in winter. However, they can be active at lower temperatures than other Apidae, due to their larger size and dense pile; they will still be active around 10°C, and can work at temperatures as high as 32°C (2).

Bumble bees are stinging insects, though they tend to avoid human interactions unless provoked (1). Bumble bees do not lose their stinger following each sting, therefore (unlike honey bees) are able to inject venom more than once (3). Bumble bees have been increasingly used in crop production systems to pollinate plants grown in greenhouses (1, 4).

Taxonomy

Tissue

Venom (4).

Worldwide distribution

Bumble bee venom hypersensitivity has been described in several countries, including Sweden (6), Finland (1), The Netherlands (7), and China (8).

Risk factors

Certain occupations such as gardeners, greenhouse and plant nursery workers present high exposure to bumble bees; these workers are at higher risk of becoming sensitized to the venom and develop severe allergic reactions (1, 4, 9). The length of time the person has worked in proximity to bumble bees is also a potential risk factor. In a study of greenhouse workers, 38% showed positivity to bumble bee venom. Compared to the non-hypersensitive patients, those with bumble bee hypersensitivity had worked in a greenhouse environment for longer and had higher number of stings in the preceding 12 months (1).

Scientists studying bumble bees are also at higher risk of developing hypersensitivity (6).

Living environment

Nests are usually underground, such as unused mouse burrows (2).

Worldwide distribution

Bumble bees can be found worldwide; Bombus terrestris can be found in Europe, Asia, Northern Africa and South America, whereas the habitat of B. pennsylvanicus is North America (2, 5).

Main

Injection of the venom by the stinger (3)

Other diseases

Systemic reactions to Hymenoptera venom have been described in 0.34–3% of the population, with children usually less affected. It is estimated that a quarter of fatalities due to anaphylaxis had been triggered by insect venoms (Dhami 2016). Anaphylaxis induced by bumble bee stings is possible but rare, presenting usually in people working with plants (Crivellaro 2013).

Symptoms of Hymenoptera venom hypersensitivity can be varied, ranging from localized skin reactions, to various degrees of severity in systemic reactions. The allergic reactions described as mild presented with erythema, urticaria and angioedema; moderate presented with nausea, dizziness and dyspnea; or severe presented as anaphylactic shock, asthma, loss of consciousness and potentially also cardiac and respiratory arrest (10).

In a study of 39 greenhouse workers with a confirmed bumble bee venom hypersensitivity, the type of allergic reaction ranged from skin reactions measuring less than 10 cm (74%), to larger skin reactions more than 10 cm (21%), or systemic sting reactions (5%) (1). In a case report, a 27-year old patient developed severe systemic allergic reactions to bumble bee venom, characterized by local swelling, urticaria, Quincke edema and asthma (6).

Central retinal artery occlusion (CRAO), edema and blurred vision, which progressed into unilateral loss of eyesight, were described as consequence of a bumble bee sting in a 66-year old patient. The patient also reported other severe systemic symptoms, which included coma, dizziness, nausea, vomiting and diarrhea, headache; the patient also suffered myocardial and hepatic damage (8).

In another case report, a patient suffered coronary artery ischemia following anaphylactic shock caused by a bumble bee sting. This was described as Kounis syndrome – i.e. allergic angina syndrome which may progress into myocardial infarction (11).

Allergen immunotherapy

Specific immunotherapy (SIT) has been shown to be useful for the treatment of hymenoptera venom allergy (HVA) (9). In particular, there appears to be two distinct populations of patients with bumble bee hypersensitivity: those with IgE highly cross-reactive with honey bee venom, and those who appear have specific bumble bee hypersensitivity. In the first category, SIT should be carried out using honey bee venom, as the reactions to bumble bee stings result from earlier exposure to honey bee venom and antigen cross-reactivity. In the second patient category, heavily exposed to bumble bee stings only, SIT would be more effective if carried out with purified bumble bee venom (1, 4, 6, 13). SIT is an appropriate treatment option for patients who cannot completely avoid exposure to bumble bee venom and its efficacy can be monitored by sting challenge (Roll 2005). Furthermore, SIT for Hymenoptera venom has been shown to be safe to administer to patients undergoing treatment for cardiovascular disease (14). Purified bumble bee venom is however not always readily available for therapy (1).

Prevention strategies

Bumble bee stings in the general population are an infrequent occurrence, due to the environment and habits of this insect (1). For people in at risk professions such as gardeners, avoidance consists of changing job (13).

Allergenic molecules

Bumble bee venom contains a number of allergens. Using proteomics techniques, compounds in bumble bee venom, 72% of which had a hom*olog in honey bee venom (12). The major allergens currently known are: phospholipase A₂ (PLA) named Bom p 1, a serine protease (casein hydrolyzing protease or Bom p 4), bombolitins, a hyaluronidase (Bom p 2), mast cell degranulating peptide and a Kunitz-type serine protease inhibitor (1, 3, 4, 12).The serine protease, also named Bt-VSP, has been shown to have fibrin(ogen)olytic properties, and is able to function as prothrombin activator and as a protease with thrombin- and plasmin-like properties (3).

The following table was adapted from Allergome.org, showing a number of allergens identified from different species of bumble bees (15).

Cross-reactivity

Evidence of cross-reactivity with honey bee venom has been described. Sera from patients with a previous history of bumble bee allergies showed positive response to honey bee venom proteins in 85% of tests (9). However, some patients who are primarily sensitized to bumble bee venom may not have cross-reactivity to honey bee venom, or only show partial cross-reactivity (6, 7).

A study of 6 serum samples from patients sensitized to Bombus terrestris showed that although cross-reactivity exists between venom of this species and the American bumble bee (B. pennsylvanicus), there are also significant species-specific differences in the allergen composition of their venom (4, 7).

Author: RubyDuke Communications

Reviewer: Dr. Christian Fischer

Last reviewed:April 2022