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

MÓNICA F. TORREZ LAMBERTI; FABIÁN E. LOPEZ; MARÍA DE LAS MERCEDES PESCARETTI,; MÓNICA A. DELGADO-CORRESPONDING AUTHOR

ANAIS DA ACADEMIA BRASILEIRA DE CIENCIAS.

ACAD BRASILEIRA DE CIENCIAS

Lugar: Rio de Janeiro; Año: 2020 vol. 94

0001-3765

25 This study was conducted to determine the emergence of antibiotic producer Shigella26 strains, focusing the efforts in the search of new antimicrobial compounds. The ability of27 388 Shigella isolates, which were originated from 15,131 fecal samples from patients with28 acute diarrhea analyzed between 2015-2017, to produce antimicrobial peptides was29 determined by deferred-antagonism assay. Here, we observed that 9.02% of the Shigella30 isolates produced an antimicrobial agent able to inhibit the E. coli AB133 strain growth.31 The CI172 strain was selected as producer for its antimicrobial characterization. This32 antagonist compound (ShpCI172) was produced during exponential growth phase and33 displayed a restricted action spectrum. It is also thermo-resistant and has about 3 kDa34 molecular mass. The ShpCI172 can be classified as a microcin, since CI172 did not display35 cross immunity with other well-known microcins. This is the first report where the36 production of a microcin by a Shigella flexneri 2 strains is described. The use of ShpCI17237 microcin may contribute to preventing or controlling diarrheal diseases. This finding38 represents an important contribution in the biotechnology field for its potential in the39 development of new antibiotics and/or food preservatives agents.