INVESTIGADORES
PESCARETTI Maria De Las Mercedes
congresos y reuniones científicas
Título:
CHARACTERIZATION OF AN ANTIMICROBIAL PEPTIDE PRODUCED BY A CLINICAL ISOLATE AC172 OF Shigella flexneri 2
Autor/es:
MONICA FLORENCIA TORREZ LAMBERTI; MARIA FLORENCIA BALLESTEROS; BIANCHI A.; FABIAN E. LOPEZ; JUAN VICENTE FARIZANO; MARÍA DE LAS MERCEDES PESCARETTI; MÓNICA A. DELGADO
Reunión:
Congreso; SAMIGE; 2017
Resumen:
The objective of this work was to characterize the antimicrobial peptide produced by AC172strain. This strain was isolated in the summer period 2016-2017 from a pediatric patient with enterocolitis, attended in the Centro Provincial de Salud Infantil Eva Perón (CePSI-Santiago del Estero province). The biochemical and serology tests classified this strain as a member of the Shigella flexneri 2 genus. In this study, we analyzed the antibiotic resistance profile of the strain using the antibiotics-disc technique, which was presented as a drug multiple-resistant strain. We also analyzed the AC172 plasmid profile, detecting the presence of a large number of these extrachromosomal elements. In addition, we determined that this strain is able to produce a growth inhibitory substances using the plates diffusion method and theE. coli AB1133 strain as sensitive.This inhibitory substance was characterization by a cell free supernatant obtained after the culture of AC172 in LB during stationary phase. The protein nature of this was determined by treating the supernatant with protease (1mg / ml) for 2 hours at 37 ° C and subsequent plate inhibition capacity. Moreover, it compound was found to be resistant to high temperatures, after being incubated at 100 ° C for 10 minutes. The estimated size of suchsubstance was calculatedby polyacrylamide gel electrophoresis, while the net charge thereof was determined at pH8 by 1% agarose gel electrophoresis. The results of this study allow us to suggest that it is a like-bacteriocin compound of low molecular weight, approximately 3kDa; with net negative charge, stabilityat high temperatures and of a protein nature.