Characterization of a bacteriocin produced by a clinical isolate of Shigella flexneri 2

MÓNICA F. TORREZ LAMBERTI; FABIAN E. LOPEZ; MARÍA DE LAS MERCEDES PESCARETTI (CO-CORRESPONDING AUTHOR); DELGADO, MÓNICA A.

ANAIS DA ACADEMIA BRASILEIRA DE CIENCIAS.

ACAD BRASILEIRA DE CIENCIAS

Año: 2022

0001-3765

This study was conducted to determine the emergence of antibiotic producer Shigella strains, focusing the efforts in the search of new antimicrobial compounds. We here determined the ability to produce antimicrobial peptides of 388 Shigella isolates, coming from fecal samples obtained from patients with acute diarrhea analyzed in the 2015-2017 period. Here, we observed that 9.02% of the Shigella isolates produced an antimicrobial agent able to inhibit the E. coli AB133 strain growth. The CI172 strain was selected as producer for its antimicrobial characterization. This antagonist compound (ShpCI172) was produced during exponential growth phase and displayed a restricted action spectrum. It is also thermo-resistant and has about 3 kDa molecular mass. The ShpCI172 can be classified as a microcin, since CI172 did not display cross immunity with other well-known microcins. This is the first report where the production of a microcin by a Shigella flexneri 2 strains is described. The use of ShpCI172 microcin may contribute to preventing or controlling diarrheal diseases. This finding represents an important contribution in the biotechnology field for its potential in the development of new antibiotics and/or food preservatives agents.