Antagonistic activity expressed by Shigella sonnei: identification of a putative new bacteriocin

Memórias do Instituto Oswaldo Cruz

Mireille Angela Bernardes Sousa¹  Luiz De Macedo Farias¹  Patricia Luciana De Oliveira¹  Jaqueline Silvana Moreira¹  Ana Carolina Morais Apolonio¹  Jamil Silvano Oliveira¹  Marcelo Matos Santoro¹  Edilberto Nogueira Mendes¹  Paula Prazeres Magalhaes¹ 

关键词: Shigella sonnei;    bacteriocin;    colicin;    antagonistic substance;    acute diarrhoea;   

DOI  :  10.1590/0074-0276108062013008

来源: SciELO

【 摘 要 】

Bacteriocins are antibacterial, proteinaceous substances that mediate microbial dynamics. Bacteriocin production is a highly disseminated property among all major lineages of bacteria, including Shigella. In this paper, we addressed the purification and characterisation of a bacteriocin produced by a Shigella sonnei strain (SS9) isolated from a child with acute diarrhoea. The substance was purified through ammonium-sulphate precipitation and sequential steps of chromatography. The intracellular fraction obtained at 75% ammonium sulphate maintained activity following exposure to pH values from 1-11 and storage at -80ºC for more than two years and was inactivated by high temperatures and proteases. The molecular mass of the purified bacteriocin was determined by mass spectrometry to be 18.56 kDa. The N-terminal sequence of the bacteriocin did not match any other antibacterial proteins described. A putative new bacteriocin produced by S. sonnei has been detected. This bacteriocin may represent a newly described protein or a previously described protein with a newly detected function. Considering that SS9 expresses antagonism against other diarrhoeagenic bacteria, the bacteriocin may contribute to S. sonnei virulence and is potentially applicable to either preventing or controlling diarrhoeal disease.

【 授权许可】

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