Merck
  • Home
  • Search Results
  • Insect-derived cecropins display activity against Acinetobacter baumannii in a whole-animal high-throughput Caenorhabditis elegans model.

Insect-derived cecropins display activity against Acinetobacter baumannii in a whole-animal high-throughput Caenorhabditis elegans model.

Antimicrobial agents and chemotherapy (2015-01-15)
Elamparithi Jayamani, Rajmohan Rajamuthiah, Jonah Larkins-Ford, Beth Burgwyn Fuchs, Annie L Conery, Andreas Vilcinskas, Frederick M Ausubel, Eleftherios Mylonakis
ABSTRACT

The rise of multidrug-resistant Acinetobacter baumannii and a concomitant decrease in antibiotic treatment options warrants a search for new classes of antibacterial agents. We have found that A. baumannii is pathogenic and lethal to the model host organism Caenorhabditis elegans and have exploited this phenomenon to develop an automated, high-throughput, high-content screening assay in liquid culture that can be used to identify novel antibiotics effective against A. baumannii. The screening assay involves coincubating C. elegans with A. baumannii in 384-well plates containing potential antibacterial compounds. At the end of the incubation period, worms are stained with a dye that stains only dead animals, and images are acquired using automated microscopy and then analyzed using an automated image analysis program. This robust assay yields a Z' factor consistently greater than 0.7. In a pilot experiment to test the efficacy of the assay, we screened a small custom library of synthetic antimicrobial peptides (AMPs) that were synthesized using publicly available sequence data and/or transcriptomic data from immune-challenged insects. We identified cecropin A and 14 other cecropin or cecropin-like peptides that were able to enhance C. elegans survival in the presence of A. baumannii. Interestingly, one particular hit, BR003-cecropin A, a cationic peptide synthesized by the mosquito Aedes aegypti, showed antibiotic activity against a panel of Gram-negative bacteria and exhibited a low MIC (5 μg/ml) against A. baumannii. BR003-cecropin A causes membrane permeability in A. baumannii, which could be the underlying mechanism of its lethality.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
二甲基亚砜, Hybri-Max, sterile-filtered, BioReagent, suitable for hybridoma, ≥99.7%
Sigma-Aldrich
二甲基亚砜, anhydrous, ≥99.9%
Sigma-Aldrich
二甲基亚砜, for molecular biology
Sigma-Aldrich
二甲基亚砜, ACS reagent, ≥99.9%
Sigma-Aldrich
二甲基亚砜, sterile-filtered, BioPerformance Certified, meets EP, USP testing specifications, suitable for hybridoma
Sigma-Aldrich
二甲基亚砜, suitable for HPLC, ≥99.7%
Sigma-Aldrich
二甲基亚砜, ReagentPlus®, ≥99.5%
Sigma-Aldrich
二甲基亚砜, ≥99.5% (GC), suitable for plant cell culture
Sigma-Aldrich
DAPI, for nucleic acid staining
Sigma-Aldrich
二甲基亚砜, meets EP testing specifications, meets USP testing specifications
Sigma-Aldrich
二甲基亚砜, puriss. p.a., ACS reagent, ≥99.9% (GC)
Sigma-Aldrich
二甲基亚砜, BioUltra, for molecular biology, ≥99.5% (GC)
Sigma-Aldrich
二甲基亚砜, PCR Reagent
Supelco
二甲基亚砜, analytical standard
Supelco
二甲基亚砜, for inorganic trace analysis, ≥99.99995% (metals basis)
USP
二甲基亚砜, United States Pharmacopeia (USP) Reference Standard
二甲基亚砜, European Pharmacopoeia (EP) Reference Standard
Sigma-Aldrich
二甲基亚砜, puriss. p.a., dried, ≤0.02% water
Sigma-Aldrich
8-Octanoyloxypyrene-1,3,6-trisulfonic acid trisodium salt, suitable for fluorescence, ≥90% (HPCE)
Sigma-Aldrich
二甲基亚砜, ≥99.6%, ReagentPlus®