Comparative analysis of virulence determinants and mass spectral profiles of Finnish and Lithuanian endodontic Enterococcus faecalis isolates.
BACKGROUND
Putative virulence factors of Enterococcus faecalis have been proposed by several workers and, by analogy, these have been linked to strains of endodontic origin. However, their distribution within the cell population is unknown. In the present study, isolates were taken from the dental root canals of two defined human populations, Lithuanian and Finnish, and examined for a range of virulence properties. In addition, surface-associated molecules and intracellular proteins were compared using matrix-assisted laser desorption-ionization/mass spectrometry (MALDI-TOF-MS) and ProteinChip capture/MS (SELDI-TOF-MS), respectively.


METHODS
Twenty-three Lithuanian and 35 Finnish dental root canal isolates were included. The esp, gelE, ace and efaA genes were detected by polymerase chain reaction, and cytolysin and gelatinase phenotypes were determined by hydrolysis of horse blood agar and gelatine agar, respectively. Protein extracts and surface-associated molecules of whole cells were analysed by SELDI-TOF-MS and MALDI-TOF-MS, respectively.


RESULTS
Presence of esp (n = 15), cytolysin (n = 9), ace (n = 55) and efaA (n = 58) was not statistically different in the two samples, whereas gelE and gelatinase production was detected more frequently in the Finnish material (chi-squared, P < 0.01). Analysis of protein profiles by SELDI-TOF-MS showed clustering of cytolysin-producing strains, whereas MALDI-TOF-MS generated profiles that clustered according to the samples' origin and, furthermore, to atypical quinupristin-dalfopristin susceptibility.


CONCLUSIONS
A high prevalence of virulence factors was demonstrated in both population types. SELDI-TOF-MS and MALDI-TOF-MS proved useful in distinguishing between different E. faecalis phenotypes and they may be useful technologies for elucidating the eco-distribution of E. faecalis in humans.
Reynaud af Geijersstam
A
A
Department of Endodontics, Institute of Clinical Odontology, University of Oslo, Oslo, Norway. annehr@odont.uio.no
Culak
R
R
Molenaar
L
L
Chattaway
M
M
Røslie
E
E
Peciuliene
V
V
Haapasalo
M
M
Shah
H N
HN
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D000942:Antigens, Bacterial / Q000096:biosynthesis; D001426:Bacterial Proteins / Q000032:analysis / Q000096:biosynthesis; D002352:Carrier Proteins / Q000096:biosynthesis; D003786:Dental Pulp Cavity / Q000382:microbiology*; D013293:Enterococcus faecalis / Q000187:drug effects / Q000201:enzymology / Q000235:genetics / Q000472:pathogenicity*; D005387:Finland / Q000453:epidemiology; D018093:Gelatinases / Q000096:biosynthesis; D016908:Gram-Positive Bacterial Infections / Q000382:microbiology*; D006801:Humans; D008097:Lithuania / Q000453:epidemiology; D008562:Membrane Glycoproteins / Q000096:biosynthesis; D008565:Membrane Proteins / Q000096:biosynthesis; D017720:Molecular Epidemiology; D054353:Perforin; D010485:Periapical Periodontitis / Q000453:epidemiology / Q000382:microbiology*; D052899:Pore Forming Cytotoxic Proteins / Q000096:biosynthesis; D040081:Protein Array Analysis; D020543:Proteome; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014769:Virginiamycin / Q000494:pharmacology; D037521:Virulence Factors
C121675:Ace protein, Enterococcus; D000900:Anti-Bacterial Agents; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D002352:Carrier Proteins; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D052899:Pore Forming Cytotoxic Proteins; D020543:Proteome; D037521:Virulence Factors; C116503:efaA protein, Enterococcus faecalis; C116707:enterococcal surface protein, esp; D014769:Virginiamycin; D054353:Perforin; C062940:quinupristin-dalfopristin; D018093:Gelatinases