title: Antagonistic effect of protein extracts fromStreptococcus sanguinison pathogenic bacteria and fungi of the oral cavity.
abstract: An antibacterial substance fromStreptococcus sanguinis(S. sanguinis) is known to have an inhibitory effect on putative periodontal pathogens, but its inhibitory effect on pathogens of oral candidiasis is unknown. In this study, intracellular and exocrine proteins were extracted fromS. sanguinis. The antagonistic effect of the protein extracts onPrevotella intermedia(P. intermedia) andPorphyromonas gingivalis(P. gingivalis) was detected by a well-plate technique, and the effects of the protein extracts on biofilms formed by these bacteria were evaluated by confocal laser scanning microscopy. The antagonistic effect of the protein extracts on pathogenic fungi was investigated usingCandida albicans(C. albicans) andCandida tropicalis(C. tropicalis). The growth curves ofC. albicansandC. tropicaliswere determined from ultraviolet absorption measurements, their morphological changes following treatment were observed by optical microscopy and scanning electron microscopy, and the effects of the protein extracts on the thickness of their biofilms and the distribution of dead/live bacteria within the biofilms were detected by confocal laser scanning microscopy. The results showed significant inhibitory effects of the intracellular proteins extracted fromS. sanguinison pathogenic bacteria (P. intermediaandP. gingivalis), fungi (C. albicansandC. tropicalis) and the biofilms formed by them. Furthermore, the growth curves and morphology ofC. albicansandC. tropicaliswere altered following treatment with the intracellular proteins, resulting in disc-like depressions in the surfaces of the fungal spores and mycelia. By contrast, the exocrine proteins demonstrated no significant inhibitory effect on the pathogenic bacteria, fungi and the biofilms formed by them. Thus, it may be concluded that intracellular proteins ofS. sanguinishave antibacterial activity and exert an antagonistic effect on certain pathogenic bacteria and fungi of the oral cavity.
authors.affiliation: Department of Stomatology, Hospital of Heilongjiang Province, Harbin, Heilongjiang 150036, P.R. China.
authors.forename: Shengli
authors.initials: S
authors.lastname: Ma
authors.affiliation: Department of Stomatology, Hospital of Heilongjiang Province, Harbin, Heilongjiang 150036, P.R. China.
authors.forename: Hui
authors.initials: H
authors.lastname: Li
authors.affiliation: Department of Stomatology, Hospital of Heilongjiang Province, Harbin, Heilongjiang 150036, P.R. China.
authors.forename: Chuang
authors.initials: C
authors.lastname: Yan
authors.affiliation: Department of Stomatology, Hospital of Heilongjiang Province, Harbin, Heilongjiang 150036, P.R. China.
authors.forename: Dan
authors.initials: D
authors.lastname: Wang
authors.affiliation: Department of Stomatology, Hospital of Heilongjiang Province, Harbin, Heilongjiang 150036, P.R. China.
authors.forename: Haiqing
authors.initials: H
authors.lastname: Li
authors.affiliation: Department of Stomatology, Hospital of Heilongjiang Province, Harbin, Heilongjiang 150036, P.R. China.
authors.forename: Xue
authors.initials: X
authors.lastname: Xia
authors.affiliation: Department of Stomatology, Hospital of Heilongjiang Province, Harbin, Heilongjiang 150036, P.R. China.
authors.forename: Xue
authors.initials: X
authors.lastname: Dong
authors.affiliation: Department of Stomatology, Hospital of Heilongjiang Province, Harbin, Heilongjiang 150036, P.R. China.
authors.forename: Yingnan
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, P.R. China.
authors.forename: Tingting
authors.initials: T
authors.lastname: Sun
authors.affiliation: Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, P.R. China.
authors.forename: Pengfei
authors.initials: P
authors.lastname: Hu
authors.affiliation: Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, P.R. China.
authors.forename: Weijun
authors.initials: W
authors.lastname: Guan
keywords: Streptococcus sanguinis; antagonistic effect; bacteria; exocrine proteins; fungi; intracellular proteins