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Bactericidal action of violacein revealed

Publicado em 05 maio 2019

In an article published in the journal ACS Infectious Diseases, Brazilian researchers describe the bactericidal action mechanism of violacein, a violet pigment produced by environmental bacteria, especially Chromobacterium violaceum.

According to the authors of the study, the substance targets the cytoplasmic membrane of bacteria, mainly affecting gram-positive bacteria such as those of the genera Streptococcus, Enterococcus and Listeria. Its various biological activities include the capacity to kill even bacteria that have become resistant to antibiotics.

Investigation - Support - São - Paulo - Research

The investigation was conducted with support from São Paulo Research Foundation—FAPESP by the research groups led by Frederico Gueiros-Filho at the University of São Paulo's Chemistry Institute (IQ-USP) and Marcelo Brocchi at the University of Campinas's Biology Institute (IB-UNICAMP).

"This pigment's powerful bactericidal properties were discovered in 1945, yet its action mechanism has never been studied before. Many biologically active molecules are described in the literature, but if we want to use them to develop drugs, we have to know how they work," Gueiros-Filho said.

Violacein - Pigment - Amino - Acid - Tryptophan

Violacein is a natural pigment derived from the amino acid tryptophan. It is produced as a secondary metabolite by several phylogenetically distinct bacteria found in environments as diverse as oceans, glaciers, rivers and soil. C. violaceum is the first bacterium described as a violacein producer and the most studied to date.

Violacein has attracted attention because of its wide biological activity spectrum. In addition to its potent activity against bacteria, including drug-resistant pathogens such as methicillin-resistant Staphylococcus aureus (MRSA), it has antifungal, antiprotozoal, antiviral, antitumor and antioxidant properties. Several studies describe these properties, but according to Gueiros-Filho, violacein's target and mode of action had never before been precisely identified.

Step - Study - Bacteria - Species - S

The first step of the study, he explained, consisted of treating bacteria of the species S. aureus and Bacillus subtilis with violacein. Using fluorescence microscopy and a set of indicator dyes, the group found that the pigment...

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