Dataset Information

Pyrethroid neurotoxicity studies with bifenthrin indicate a mixed Type I/II mode of action.

ABSTRACT: BACKGROUND:Bifenthrin is usually considered a Type I pyrethroid, because it lacks an ?-CN group present in Type II pyrethroids, but some previous studies suggest a mixed Type I/II mode-of-action. Results are presented for bifenthrin in a rat developmental neurotoxicity (DNT) study along with effects on Na currents in human VGSC subtypes. Molecular modeling comparisons were also made for bifenthrin and other pyrethroids. RESULTS:In a rat DNT study, bifenthrin produced tremors and clonic convulsions in dams and pups and slightly reduced acoustic startle response amplitude, and increased Tmax, at PND20 in females. Similar blood levels of bifenthrin were measured in dams and pups at each dose level i.e. no concentration in pups. In human VGSC experiments, using the Nav1.8 subtype, bifenthrin's effects on inactivation were slight, as for Type II pyrethroids, but without large prolongation of the tail current (deactivation) seen with Type II. Molecular modeling of bifenthrin indicates that the o-Me group may occupy a similar space to the ?-CN group of cypermethrin and fenpropathrin. CONCLUSION:In a DNT study and on human Nav1.8 tail currents bifenthrin showed Type I and II effects, similar to some published studies. Overall, bifenthrin acts as a mixed Type I/II pyrethroid. © 2018 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

SUBMITTER: Gammon DW

PROVIDER: S-EPMC6590159 | biostudies-literature | 2019 Apr

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Pyrethroid neurotoxicity studies with bifenthrin indicate a mixed Type I/II mode of action.

Gammon Derek W DW Liu Zhiwei Z Chandrasekaran Appavu A El-Naggar Shaaban F SF Kuryshev Yuri A YA Jackson Sharon S

Pest management science 20190130 4

<h4>Background</h4>Bifenthrin is usually considered a Type I pyrethroid, because it lacks an α-CN group present in Type II pyrethroids, but some previous studies suggest a mixed Type I/II mode-of-action. Results are presented for bifenthrin in a rat developmental neurotoxicity (DNT) study along with effects on Na currents in human VGSC subtypes. Molecular modeling comparisons were also made for bifenthrin and other pyrethroids.<h4>Results</h4>In a rat DNT study, bifenthrin produced tremors and c ...[more]

PMID: 30548793

Similar Datasets

Project description:Cervimycins A-D are bis-glycosylated polyketide antibiotics produced by Streptomyces tendae HKI 0179 with bactericidal activity against Gram-positive bacteria. In this study, cervimycin C (CmC) treatment caused a spaghetti-like phenotype in Bacillus subtilis 168, with elongated curved cells, which stayed joined after cell division, and exhibited a chromosome segregation defect, resulting in ghost cells without DNA. Electron microscopy of cervimycin treated S. aureus (3 x MIC) revealed swollen cells, misshapen septa, cell wall thickening, and a rough cell wall surface. Incorporation tests in B. subtilis indicated an effect on DNA biosynthesis at high cervimycin concentrations. Indeed, artificial down-regulation of the DNA gyrase subunit B gene (gyrB) increased the activity of cervimycin in agar diffusion tests, and, in high concentrations (starting at 62.5 x MIC), the antibiotic inhibited S. aureus DNA gyrase supercoiling activity in vitro. To obtain a more global view on the mode of action of CmC, transcriptomics and proteomics of cervimycin treated versus untreated S. aureus cells were performed. Interestingly, 3 x MIC of cervimycin did not induce the SOS response, which would indicate disturbance of the DNA gyrase activity in vivo. Instead, cervimycin induced the expression of the CtsR/HrcA heat shock operon and the expression of autolysins, exhibiting similarity to the ribosome-targeting gentamicin. In summary, we identified the DNA gyrase as a target, but at low concentrations electron microscopy and omics data revealed a more complex mode of action of cervimycin, that comprised induction of the heat shock response, indicating protein stress in the cell. A synergistic effect was seen when sodium chloride (NaCl) was added during cervimycin MIC testing of S. aureus SG511. Thus, transcriptomics of S. aureus cells under osmotic stress (1 M NaCl) were performed. The stress response was compared to the cervimycin stress response to identify factors which might contribute to the synergistic antibacterial effect of the two molecules.

Dataset Information

Pyrethroid neurotoxicity studies with bifenthrin indicate a mixed Type I/II mode of action.

Publications

Pyrethroid neurotoxicity studies with bifenthrin indicate a mixed Type I/II mode of action.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets