CERELA   05438
CENTRO DE REFERENCIA PARA LACTOBACILOS
Unidad Ejecutora - UE
artículos
Título:
Sensitivity of capsular-producing Streptococcus thermophilus strains to bacteriophage adsorption.
Autor/es:
RODRÍGUEZ C, VAN DER MEULEN R, VANINGELGEM F, FONT DE VALDEZ G, RAYA R, DE VUYST L, MOZZI F.
Revista:
LETTERS IN APPLIED MICROBIOLOGY
Editorial:
Blackwell Scientific Publications
Referencias:
Lugar: England; Año: 2007 vol. 46 p. 462 - 462
ISSN:
0266-8254
Resumen:
Aims: To determine whether the presence and type of exopolysaccharides (EPS), slime-EPS or capsular, and the structural characteristics of the polymers produced by Streptococcus thermophilus strains could interfere with or be involved in phage adsorption. Methods and Results: Phage–host interactions between eight EPS-producing Strep. thermophilus strains (CRL419, 638, 804, 810, 815, 817, 821, 1190) and five streptococcus specific phages (/Ysca, /3, /5, /6, /8) isolated from Argentinean faulty fermentation failed yoghurts were evaluated. No relationship was found between the EPS chemical composition and the phage sensitivity ⁄ resistance phenotype. In general, the capsular-producing strains were more sensitive to phage attacks than the  noncapsular-producing strains. Streptococcus thermophilus CRL1190 (capsular-producing) was the only strain sensitive to all bacteriophages and showed the highest efficiency of plating. Phage adsorption to a capsular-negative, EPS low-producing mutant of strain CRL1190 was reduced, especially for /Ycsa and /8. Conclusions: The presence of capsular polysaccharide surrounding the cells of Strep. thermophilus strains could play a role in the adsorption of specific phages to the cells. Significance and Impact of the Study: Capsular-producing Strep. thermophilus strains should be evaluated for their bacteriophage sensitivity if they are included in starter cultures for the fermented food industry.