A new antibiotic that selectively acts against Gram-negative bacteria have been discovered in the nematode, Photorhabdus . They named the antibiotic Darobactin . Darobactin is coded by a silent operon and has an unusual structure with two fused rings that are formed post-translationally. It is produced in very low quantity in laboratory conditions and is synthesized ribosomally . The Compound is active against Gram-negative bacteria both in vitro and in animal models of infection. The last time we discovered a class of antibiotics against gram-negative was in the 1960s. References : A new antibiotic selectively kills Gram-negative pathogens. Nature 2019
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