TY - JOUR
T1 - The rag locus of Porphyromonas gingivalis
T2 - A novel pathogenicity island
AU - Curtis, M. A.
AU - Hanley, S. A.
AU - Aduse-Opoku, J.
PY - 1999
Y1 - 1999
N2 - Previous studies in our laboratories of the serum IgG antibody response of periodontal patients have demonstrated the presence of an immunodominant surface antigen (Mr 55 kDa) in the outer membrane of Porphyromonas gingivalis W50. Genetic analysis of this antigen revealed that the corresponding gene forms part of a small operon which may have arisen via horizontal gene transfer into the genome of this strain. On the basis of sequence homology, the 55 kDa antigen (RagB) and the product of a cotranscribed gene (RagA) may act in concert at the surface of the bacterium to facilitate active transport, mediated through the periplasmic spanning protein, TonB, or form part of a signal transduction system in this organism. The rag locus is present in only a proportion of P. gingivaux laboratory strains and clinical isolates. Analysis of the distribution of ragB in subgingival samples by PCR demonstrated that rag+ P. gingivalis are more frequently detected in deep periodontal pockets than shallow sites in periodontal patients. These findings indicate that the rag genes may influence the virulence potential of P. gingivalis strains which harbour this locus and may thus be considered a novel pathogenicity island. Furthermore, horizontal gene transfer between organisms in subgingival plaque may represent a significant force in the evolution of these bacteria with ramifications for both diagnosis and targeted treatment of periodontal disease.
AB - Previous studies in our laboratories of the serum IgG antibody response of periodontal patients have demonstrated the presence of an immunodominant surface antigen (Mr 55 kDa) in the outer membrane of Porphyromonas gingivalis W50. Genetic analysis of this antigen revealed that the corresponding gene forms part of a small operon which may have arisen via horizontal gene transfer into the genome of this strain. On the basis of sequence homology, the 55 kDa antigen (RagB) and the product of a cotranscribed gene (RagA) may act in concert at the surface of the bacterium to facilitate active transport, mediated through the periplasmic spanning protein, TonB, or form part of a signal transduction system in this organism. The rag locus is present in only a proportion of P. gingivaux laboratory strains and clinical isolates. Analysis of the distribution of ragB in subgingival samples by PCR demonstrated that rag+ P. gingivalis are more frequently detected in deep periodontal pockets than shallow sites in periodontal patients. These findings indicate that the rag genes may influence the virulence potential of P. gingivalis strains which harbour this locus and may thus be considered a novel pathogenicity island. Furthermore, horizontal gene transfer between organisms in subgingival plaque may represent a significant force in the evolution of these bacteria with ramifications for both diagnosis and targeted treatment of periodontal disease.
KW - Gene transfer
KW - Pathogenicity islands
KW - Porphyromonas gingivalis
KW - TonB
UR - http://www.scopus.com/inward/record.url?scp=0033201677&partnerID=8YFLogxK
U2 - 10.1111/j.1600-0765.1999.tb02273.x
DO - 10.1111/j.1600-0765.1999.tb02273.x
M3 - Article
C2 - 10685368
AN - SCOPUS:0033201677
SN - 0022-3484
VL - 34
SP - 400
EP - 405
JO - Journal of Periodontal Research
JF - Journal of Periodontal Research
IS - 7
ER -