Screening for subgingival occurrence of gram-negative enteric rods in periodontally diseased and healthy subjects.

OBJECTIVE

This study aimed to determine whether the variations in the occurrence of gram-negative enteric rods as detected through a longitudinal follow up with three consecutive visits, may be associated with the periodontal clinical status.

DESIGN

Clinical and demographic parameters from 63 untreated chronic periodontitis (CP) subjects and 45 healthy controls (HC) were analyzed. Subgingival plaque samples were obtained from 6 sites in each subject at baseline, 1-week, and 1-month visits and processed using culture and biochemical tests. Culture findings were categorized taking into account the detection frequency of gram-negative enteric rods as persistent presence, transient presence, or absence of enteric rods in any sampling time.

RESULTS

Although transient presence of gram-negative enteric rods was more prevalent in CP subjects (16.7%) than HC subjects (9.3%), the difference was not significant (P>0.05). The majority of subjects showed a transient presence of gram-negative enteric rods at concentrations <2 x 10(2)CFU/mL. Persistent presence of gram-negative enteric rods was not observed in any subject through the entire study period. Moreover, differences in both the detection frequencies of individual species and the total number of gram-negative enteric rods were not statistically significant neither inter- nor intragroups.

CONCLUSION

The findings of the present study could indicate that gram-negative enteric rods are merely transient microorganisms within the subgingival environment and suggest that the periodontal clinical status appeared not to be influenced by the presence of these species.