Antimicrobial activity of Yersinia spp. bacteriocins producing strains on different biotypes of Y. enterocolitica.

BRARDA, BRENDA; IRIARTE, HEBE JORGELINA; CECILIA LUCERO ESTRADA; ESCUDERO MARÍA ESTHER; FAVIER GABRIELA ISABEL

Mendoza

Congreso; XXX Reunión Científica Anual de la Sociedad de Biología de Cuyo. Sociedad Biología de Cuyo; 2022

Sociedad de Biología de Cuyo

Bacteriocins are polypeptides that have the ability to be bactericidal or bacteriostatic against sensitive bacteria of the same or closely related species. The producing cells are immune to their bacteriocins. Non-pathogenic Yersinia species studied in our laboratories, such as Y. intermedia and Y. enterocolitica biotype (B) 1A, are bacteriocin producers and exhibited an inhibitory effect on pathogenic Y. enterocolitica strains associated with gastrointestinal pathologies and immunological sequelae in humans. The aim of this work was to evaluate the antimicrobial activity of non-pathogenic Yersinia spp. bacteriocins producing strains (BPS) on pathogenic Y. enterocolitica biotypes. For this purpose, Y. intermedia B1 O:35-37-40 (MEE 019) and Y. enterocolitica B1A O:5 (LVF 010) were used as BPS. Y. enterocolitica B1B (WAP+), Y. enterocolitica B2 (W1024, GFB002, and GFO041), Y. enterocolitica B3 (GFO045), and Y. enterocolitica B4 (MHC700, 29C/43, GFO64CH and GFO68CH), were used as indicator strains (IS). The ?spot technique? was performed. Briefly, BPS and IS were cultured in trypticase soy broth at 25°C for 18 h and adjusted to a concentration corresponding to a DOʎ610 0.2. Aliquots of each BPS were placed in wells of culture media previously inoculated with IS and incubated at 20°C for 48 h, in duplicate. The sensitivity or resistance results of the IS were determined by the presence or absence of halos around the BPS. In addition, diameters of halos were measured in millimeters with a digital caliper. WAP+, GFO041, GFB002, MHC700, 29C/43, GFO64CH, and GFO68CH were sensitive to both BPS tested. Y. enterocolitica W1024 was resistant to both BPS, and Y. enterocolitica GFO045 was sensitive to Y. enterocolitica LVFO10 but resistant to Y. intermedia MEE019. These results encourage the hypothesis that bacteriocins produced by Yersinia strains considered non-pathogenic have antagonistic capacity against pathogenic Y. enterocolitica strains and would suggest that antimicrobial effect of these bacteriocins is specific of the strain but it has no relationship with the Y. enterocolitica biotype.