The German cockroach, Blattella germanica (L.), has been implicated as a major cause of allergic disease. Bla g1 is one of several allergens that can trigger asthma. The amino acid sequence of Bla g1 has been shown to be similar to a mosquito midgut protein precursor; it is thought to serve a digestive function. The goal of this research was to determine the tissue distribution of Bla g1 and evaluate factors affecting its production and content in feces. Tissues from 5-day-old adult females were dissected, extracted, and assayed using a two-site monoclonal ELISA. Results indicate that Bla g1 is highest in the digestive tract. The time-course of feces production and its Bla g1 content were assayed for 20 days following eclosion. Fecal Bla g1 changed in relation to the reproductive cycle and food intake. We conclude that Bla g1 production is elevated in response to food intake resulting in a higher allergen titer in feces.
Although there appears to be a positive correlation between exposure to German cockroaches and respiratory disease in residential settings, little is known about exposure in the workplace. The confined swine production environment supports large cockroach infestations, which are expected to expose workers and animals to high levels of allergens. We evaluated the spatial distribution of Bla g1 in a swine farm in relation to cockroach population level and production practices. Settled dust on floors and other surfaces in various rooms were sampled with sterile swabs and a modified vacuum cleaner. High levels of Bla g1 were found on all surfaces, suggesting extensive worker and animal exposure to this allergen. Insight into the environmental distribution of Bla g1 should aid in understanding its interaction with other farm allergens and in developing allergen mitigation plans.
The ESA 2001 Annual Meeting - 2001: An Entomological Odyssey of ESA