This article is more than 5 years old. Information may no longer be current.
Newly discovered antibiotic in nose viewed as preventive against MRSA
Click Here to Manage Email Alerts
Researchers in Germany discovered a previously unknown antibiotic that is produced in human noses and think it has the potential to be used as prophylaxis against Staphylococcus aureus, including MRSA.
“Normally antibiotics are formed only by soil bacteria and fungi,” Andreas Peschel, PhD, professor of cellular and molecular microbiology at the University of Tübingen, said in a news release. “The notion that human microflora may also be a source of antimicrobial agents is a new discovery.”
A novel antibiotic
Peschel and colleagues discovered that nasal strains of S. lugdunensis produced a thiazolidine-containing cyclic peptide antibiotic, which they named lugdunin.
Their research was published in Nature.
In an examination of nasal swabs from 187 hospital patients, Peschel and colleagues found that S. aureus and S. lugdunensis were rarely present at the same time. (Overall, S. aureus colonized 32.1% of noses and S. lugdunensis was found in 9.1%, lining up with previously published data.)
In fact, just 5.9% of patients whose noses contained S. lugdunensis also showed colonization with S. aureus, compared with 34.7% of S. lugdunensis-negative patients — a nearly sixfold decrease. This significant reduction indicated to Peschel and colleagues that “strong interference precludes the simultaneous presence of S. aureus and S. lugdunensis in the human nose.”
Lugdunin reduced or completely eradicated viable S. aureus on the surface and in deeper layers of skin in mice. It also was able to kill S. aureus in the noses of cotton rats — further evidence that S. lugdunensis could be potent against colonization of S. aureus in the human nose, Peschel and colleagues wrote.
“The human predisposition to S. aureus nasal carriage is governed by several host genetic or microbiota-related factors, which may affect the capacity of S. aureus to adhere to and multiply on nasal epithelia,” they wrote. “Here we provide evidence for a crucial role of S. lugdunensis and its antimicrobial product, lugdunin, in preventing S. aureus colonization of the human nose.”
In a digitally colored scanning electron micrograph, MRSA bacteria are consumed by a human neutrophil white blood cell.
Source: National Institute of Allergy and Infectious Diseases.
Further, Peschel and colleagues did not observe resistance to lugdunin.
“This indicates that lugdunin has apparently evolved for the purpose of bacterial elimination in the human organism, implying that it is optimized for efficacy and tolerance at its physiological site of action,” they wrote. “Thus, lugdunin shows promise as a potential drug for inhibiting growth of S. aureus in the nares and potentially other body sites.”
More antibiotics yet to be discovered
In a related commentary also published in Nature, Kim Lewis, PhD, director of the antimicrobial discovery center in the department of biology, and Philip Strandwitz, PhD, a postdoctoral fellow, both at Northeastern University, said it could be problematic to develop lugdunin as a systemic therapeutic because it is probably a membrane-acting antibiotic, and thus may disrupt the membranes of mammalian cells.
But they said the study by Peschel and colleagues could herald future discoveries of colonization resistance in the human microbiota that is driven by antibiotics.
“When produced by a bacterium that occupies a confined niche, it is clear that lugdunin and similar antibiotics have considerable power to influence bacterial community structure,” Lewis and Strandwitz wrote. “Given that S. lugdunensis is present in only around 10% of the population and S. aureus is found in about 30% of the population, there are probably more antibiotics yet to be discovered that are responsible for S. aureus colonization resistance,” they wrote. – by Gerard Gallagher
Disclosure: The researchers report no relevant financial disclosures.
Click Here to Manage Email Alerts