Biofilm-like structures and pathogenicity of Escherichia hermannii YS-11, a clinical isolate from a persistent apical periodontitis lesion.
Escherichia hermannii, formerly classified as enteric group 11 of Escherichia coli, is considered to be nonpathogenic. In this report, we described some of the pathogenic properties of a viscous material-producing E. hermannii strain YS-11, which was clinically isolated from a persistent apical periodontitis lesion. YS-11 possessed cell surface-associated meshwork-like structures that are found in some biofilm-forming bacteria and its viscous materials contained mannose-rich exopolysaccharides. To further examine the biological effect of the extracellular viscous materials and the meshwork structures, we constructed a number of mutants using transposon mutagenesis. Strain 455, which has a transposon inserted into wzt, a gene that encodes an ATP-binding cassette transporter, lacked the expression of the cell surface-associated meshwork structures and the ability to produce extracellular materials. Complementation of the disrupted wzt in strain 455 with an intact wzt resulted in the restoration of these phenotypes. We also compared these strains in terms of their ability to induce abscess formation in mice as an indication of their pathogenicity. Strains with meshwork-like structures induced greater abscesses than those induced by strains that lacked such structures. These results suggest that the ability to produce mannose-rich exopolysaccharides and to form meshwork-like structures on E. hermannii might contribute to its pathogenicity.
Yamanaka
Takeshi
T
Department of Bacteriology, Osaka Dental University, Hirakata-shi, Osaka, Japan. yamanaka@cc.osaka-dent.ac.jp
Sumita-Sasazaki
Yoko
Y
Sugimori
Chieko
C
Matsumoto-Mashimo
Chiho
C
Yamane
Kazuyoshi
K
Mizukawa
Kenji
K
Yoshida
Masahiro
M
Hayashi
Hiroyuki
H
Nambu
Takayuki
T
Leung
Kai-Poon
KP
Fukushima
Hisanori
H
D018528:ATP-Binding Cassette Transporters / Q000235:genetics; D000038:Abscess / Q000382:microbiology / Q000473:pathology; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics; D018441:Biofilms / Q000254:growth & development*; D004251:DNA Transposable Elements; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004195:Disease Models, Animal; D004756:Enterobacteriaceae Infections / Q000382:microbiology / Q000473:pathology; D004925:Escherichia / Q000235:genetics / Q000302:isolation & purification* / Q000472:pathogenicity / Q000502:physiology*; D017353:Gene Deletion; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D010485:Periapical Periodontitis / Q000382:microbiology*; D011135:Polysaccharides, Bacterial / Q000378:metabolism; D017422:Sequence Analysis, DNA; D014774:Virulence
D018528:ATP-Binding Cassette Transporters; D001426:Bacterial Proteins; D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D011135:Polysaccharides, Bacterial