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Deep sequencing of pyrethroid-resistant bed bugs reveals multiple mechanisms of resistance within a single population.

Adelman ZN, Kilcullen KA, Koganemaru R, Anderson MA, Anderson TD, Miller DM - PLoS ONE (2011)

Bottom Line: Using LD(50) bioassays, we determined that resistance ratios for Richmond strain bed bugs were ∼5200-fold to the insecticide deltamethrin.Following assembly, analysis of newly identified gene transcripts in both Harlan (susceptible) and Richmond (resistant) bed bugs revealed several candidate cytochrome P450 and carboxylesterase genes which were significantly over-expressed in the resistant strain, consistent with the idea of increased metabolic resistance.These data will accelerate efforts to understand the biochemical basis for insecticide resistance in bed bugs, and provide molecular markers to assist in the surveillance of metabolic resistance.

View Article: PubMed Central - PubMed

Affiliation: Fralin Life Science Institute and Department of Entomology, Virginia Tech, Blacksburg, Virginia, United States of America. zachadel@vt.edu

ABSTRACT
A frightening resurgence of bed bug infestations has occurred over the last 10 years in the U.S. and current chemical methods have been inadequate for controlling this pest due to widespread insecticide resistance. Little is known about the mechanisms of resistance present in U.S. bed bug populations, making it extremely difficult to develop intelligent strategies for their control. We have identified bed bugs collected in Richmond, VA which exhibit both kdr-type (L925I) and metabolic resistance to pyrethroid insecticides. Using LD(50) bioassays, we determined that resistance ratios for Richmond strain bed bugs were ∼5200-fold to the insecticide deltamethrin. To identify metabolic genes potentially involved in the detoxification of pyrethroids, we performed deep-sequencing of the adult bed bug transcriptome, obtaining more than 2.5 million reads on the 454 titanium platform. Following assembly, analysis of newly identified gene transcripts in both Harlan (susceptible) and Richmond (resistant) bed bugs revealed several candidate cytochrome P450 and carboxylesterase genes which were significantly over-expressed in the resistant strain, consistent with the idea of increased metabolic resistance. These data will accelerate efforts to understand the biochemical basis for insecticide resistance in bed bugs, and provide molecular markers to assist in the surveillance of metabolic resistance.

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Comparison of general esterase (EST), glutathione S-transferase (GST), and cytochrome P450-dependent O-deethylation (P450) activities of insecticide-susceptible and-resistant bed bugs.Vertical bars indicate standard errors of the mean (n = 4), asterisks (*) denote that the means are significantly different between the two bed bug strains (two-tailed t-test, P<0.05).
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pone-0026228-g001: Comparison of general esterase (EST), glutathione S-transferase (GST), and cytochrome P450-dependent O-deethylation (P450) activities of insecticide-susceptible and-resistant bed bugs.Vertical bars indicate standard errors of the mean (n = 4), asterisks (*) denote that the means are significantly different between the two bed bug strains (two-tailed t-test, P<0.05).

Mentions: To examine the possibility of metabolic resistance in Richmond strain bed bugs, we determined the general esterase, glutathione S-transferase, and cytochrome P450 monooxygenase activities of these detoxification enzymes in both the Harlan and Richmond strains (Fig. 1). We found that the general esterase activity of deltamethrin-resistant bed bugs was significantly increased (by 35% and 38% when α-NA and β-NA are used as substrates, respectively) compared to the insecticide-susceptible Harlan strain bed bugs (P<0.05). The cytochrome P450 O-deethylation activity of the Richmond strain bed bugs was also significantly enhanced by 41% compared to the insecticide-susceptible bed bugs (P<0.05). In contrast, glutathione S-transferase activity of deltamethrin-resistant bed bugs did not differ from that of the susceptible strain. These data suggest that increased esterase and P450 activities may play a role in detoxifying the pyrethroid deltamethrin.


Deep sequencing of pyrethroid-resistant bed bugs reveals multiple mechanisms of resistance within a single population.

Adelman ZN, Kilcullen KA, Koganemaru R, Anderson MA, Anderson TD, Miller DM - PLoS ONE (2011)

Comparison of general esterase (EST), glutathione S-transferase (GST), and cytochrome P450-dependent O-deethylation (P450) activities of insecticide-susceptible and-resistant bed bugs.Vertical bars indicate standard errors of the mean (n = 4), asterisks (*) denote that the means are significantly different between the two bed bug strains (two-tailed t-test, P<0.05).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3198472&req=5

pone-0026228-g001: Comparison of general esterase (EST), glutathione S-transferase (GST), and cytochrome P450-dependent O-deethylation (P450) activities of insecticide-susceptible and-resistant bed bugs.Vertical bars indicate standard errors of the mean (n = 4), asterisks (*) denote that the means are significantly different between the two bed bug strains (two-tailed t-test, P<0.05).
Mentions: To examine the possibility of metabolic resistance in Richmond strain bed bugs, we determined the general esterase, glutathione S-transferase, and cytochrome P450 monooxygenase activities of these detoxification enzymes in both the Harlan and Richmond strains (Fig. 1). We found that the general esterase activity of deltamethrin-resistant bed bugs was significantly increased (by 35% and 38% when α-NA and β-NA are used as substrates, respectively) compared to the insecticide-susceptible Harlan strain bed bugs (P<0.05). The cytochrome P450 O-deethylation activity of the Richmond strain bed bugs was also significantly enhanced by 41% compared to the insecticide-susceptible bed bugs (P<0.05). In contrast, glutathione S-transferase activity of deltamethrin-resistant bed bugs did not differ from that of the susceptible strain. These data suggest that increased esterase and P450 activities may play a role in detoxifying the pyrethroid deltamethrin.

Bottom Line: Using LD(50) bioassays, we determined that resistance ratios for Richmond strain bed bugs were ∼5200-fold to the insecticide deltamethrin.Following assembly, analysis of newly identified gene transcripts in both Harlan (susceptible) and Richmond (resistant) bed bugs revealed several candidate cytochrome P450 and carboxylesterase genes which were significantly over-expressed in the resistant strain, consistent with the idea of increased metabolic resistance.These data will accelerate efforts to understand the biochemical basis for insecticide resistance in bed bugs, and provide molecular markers to assist in the surveillance of metabolic resistance.

View Article: PubMed Central - PubMed

Affiliation: Fralin Life Science Institute and Department of Entomology, Virginia Tech, Blacksburg, Virginia, United States of America. zachadel@vt.edu

ABSTRACT
A frightening resurgence of bed bug infestations has occurred over the last 10 years in the U.S. and current chemical methods have been inadequate for controlling this pest due to widespread insecticide resistance. Little is known about the mechanisms of resistance present in U.S. bed bug populations, making it extremely difficult to develop intelligent strategies for their control. We have identified bed bugs collected in Richmond, VA which exhibit both kdr-type (L925I) and metabolic resistance to pyrethroid insecticides. Using LD(50) bioassays, we determined that resistance ratios for Richmond strain bed bugs were ∼5200-fold to the insecticide deltamethrin. To identify metabolic genes potentially involved in the detoxification of pyrethroids, we performed deep-sequencing of the adult bed bug transcriptome, obtaining more than 2.5 million reads on the 454 titanium platform. Following assembly, analysis of newly identified gene transcripts in both Harlan (susceptible) and Richmond (resistant) bed bugs revealed several candidate cytochrome P450 and carboxylesterase genes which were significantly over-expressed in the resistant strain, consistent with the idea of increased metabolic resistance. These data will accelerate efforts to understand the biochemical basis for insecticide resistance in bed bugs, and provide molecular markers to assist in the surveillance of metabolic resistance.

Show MeSH
Related in: MedlinePlus