Time- and tissue-specific antimicrobial activity of the common bed bug in response to blood feeding and immune activation by bacterial injection.

Unlike almost all hematophagous insects, common bed bugs, Cimex lectularius, are not known to transmit pathogens to humans. To help unravel the reasons for their lack of vector competence, we studied the time- and tissue-dependent expression of innate immune factors after blood feeding or immune activation through the intrathoracic injection of bacteria. We used minimum inhibitory concentration (MIC) bioassays and the Kirby-Bauer protocol to evaluate antimicrobial peptide (AMP) activity in tissue extracts from the midguts or 'rest of body' (RoB) tissues (containing hemolymph and fat body AMPs) against Gram-positive and Gram-negative bacteria.