In a recent study published in the journal Nature , researchers in the United States of America designed and discovered lolamicin, a selective antibiotic that targets the lipoprotein transport system in Gram-negative bacteria. They found that lolamicin was effective against multidrug-resistant Gram-negative pathogens, showed efficacy in mouse infection models, spared the gut microbiome, and prevented secondary infections. Study: A Gram-negative-selective antibiotic that spares the gut microbiome .
Image Credit: Kateryna Kon / Shutterstock Antibiotic treatment can disrupt the gut microbiome, leading to increased susceptibility to pathogens like C. difficile and higher risks of gastrointestinal, renal, and hematological issues. Most antibiotics, whether Gram-positive-only or broad-spectrum, harm gut commensals and cause dysbiosis.
The impact of Gram-negative-only antibiotics on the microbiome is unclear due to the scarcity of such compounds. Their discovery was challenging because most antibiotic targets are shared by both Gram-positive and Gram-negative bacteria. Since the gut microbiome contains many Gram-negative bacteria, indiscriminate Gram-negative antibiotics such as colistin can cause significant dysbiosis, limiting their use.
Despite the rising need for new Gram-negative antibacterial agents due to resistant infections, no new class has been approved by the Food and Drug Administration (FDA) in over 50 years. Discovery is complicated by Gram-negative bacteria's complex.
