Characterization of a new serotype g isolate of Aggregatibacter actinomycetemcomitans.
Aggregatibacter actinomycetemcomitans is usually isolated from the oral cavity where it is associated with active periodontitis. The species can be divided into six serotypes (a-f) according to their surface carbohydrate antigens. However, some clinical isolates cannot be grouped within these six serotypes. Gram-negative, facultative anaerobic, catalase-positive coccobacilli were isolated from a patient with periodontitis and identified by employing genetic, biochemical and serological analyses. Phenotypic data identified the isolate as A. actinomycetemcomitans. Serotype-specific polysaccharide antigen from the isolate was untypeable by immunodiffusion testing in comparison with reference A. actinomycetemcomitans serotype a to f strains. Biofilm formation by the isolate was strong but cytotoxic activity was low. Gas chromatography/mass spectroscopy analysis of partially methylated alditol acetates from surface polysaccharide showed the presence of 2,4-di-O-methyl-rhamnose and 2,3,6-tri-O-methyl-glucose, with a 1 : 1 m ratio. The (1)H- and (13)C-nuclear magnetic resonance spectra of the antigen showed that both constituent glycoses had alpha-anomeric configuration. It is proposed that the untyped strain is a new A. actinomycetemcomitans serotype, designated serotype g.
Department of Microbiology and Immunology, Nihon University School of Dentistry at Matsudo, Chiba, Japan. takada.kazuko@nihon-u.ac.jp
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K
Takada
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M
Saito
O
O
Tsuzukibashi
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Y
Kawashima
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Ishida
M
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Hirasawa
D016976:Aggregatibacter actinomycetemcomitans / Q000145:classification*; D018441:Biofilms; D002470:Cell Survival; D002849:Chromatography, Gas; D055113:Chronic Periodontitis / Q000382:microbiology*; D004269:DNA, Bacterial / Q000032:analysis; D018922:HL-60 Cells / Q000382:microbiology; D006801:Humans; D013058:Mass Spectrometry; D010514:Periodontal Pocket / Q000382:microbiology; D016133:Polymerase Chain Reaction; D011135:Polysaccharides, Bacterial / Q000737:chemistry*; D012703:Serotyping / Q000379:methods; D013402:Sugar Alcohols / Q000032:analysis
D004269:DNA, Bacterial; D011135:Polysaccharides, Bacterial; D013402:Sugar Alcohols