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Bacteriocin production by Shigella sonnei isolated from faeces of children with acute diarrhoea
Author(s) -
SOUSA MIREILLE ÂNGELA BERNARDES,
MENDES EDILBERTO NOGUEIRA,
APOLÔNIO ANA CAROLINA MORAIS,
FARIAS LUIZ DE MACÊDO,
MAGALHÃES PAULA PRAZERES
Publication year - 2010
Publication title -
apmis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.909
H-Index - 88
eISSN - 1600-0463
pISSN - 0903-4641
DOI - 10.1111/j.1600-0463.2009.02570.x
Subject(s) - shigella sonnei , microbiology and biotechnology , antagonism , colicin , bacteriocin , virulence , biology , escherichia coli , feces , shigella , population , shigella flexneri , chemistry , antimicrobial , medicine , biochemistry , receptor , environmental health , gene
Sousa MÂB, Mendes EN, Apolônio ACM, Farias LM, Magalhães PP. Bacteriocin production by Shigella sonnei isolated from faeces of children with acute diarrhoea. APMIS 2010; 118: 125–35. Shigella is a common agent of diarrhoea, a worldwide major health problem. The bacterium produces bacteriocins; however, the role of these substances as a virulence factor is completely unknown. With the aim to search for colicin production by Shigella sonnei , to evaluate the influence of culture conditions on bacteriocin expression, and to characterize the substance partially, 16 S. sonnei strains isolated from children with diarrhoea were tested for antagonism against members of the intestinal microbiota or agents of diarrhoea. Nine strains exhibited isoantagonism and heteroantagonism against S. flexneri and diarrhoeagenic Escherichia coli . Autoantagonism and antagonism against the intestinal microbiota were not detected. Culture medium and incubation conditions influenced antagonism expression. Antagonism resulting from bacteriophages, low pH, fatty acids, hydrogen peroxide, and chloroform was excluded. The activity of the intracellular fraction obtained with 75% ammonium sulphate was preserved at pH 1.0–11.0, and was found to be reduced by organic solvents and affected by high temperatures and proteases. The antagonistic spectrum and the in vitro conditions for better antagonism expression suggest that the role of colicin in S. sonnei virulence, if any, would be expressed prior to infection, and may regulate population density of enteropathogens by helping in organism transmission.