Aggregatibacter actinomycetemcomitans-induced bone loss and antibody response in three rat strains.
BACKGROUND
The aim of this study is to compare the colonization, immunoglobulin (Ig) G response, and alveolar bone loss in Aggregatibacter actinomycetemcomitans (Aa)-inoculated Fawn Hooded Hypertensive (FHH), Dahl Salt-Sensitive (DSS), and Brown Norway (BN) rats.


METHODS
Each rat strain was divided into wild-type Aa-inoculated and non-inoculated control groups. Blood taken at 12 weeks after inoculation was assessed for Aa-specific IgG antibodies by an enzyme-linked immunosorbent assay. Colonization was assessed 12 weeks postinoculation. Bone loss was estimated by measuring the distance from the cemento-enamel junction (CEJ) to the alveolar bone crest (ABC) at 20 molar sites. Colonization and antibody levels were compared by using the Student t test. Diseased rats were defined as having two sites per quadrant with CEJ-ABC distances that were significantly greater than the control CEJ-ABC distances.


RESULTS
The Aa colonization of FHH rats was significantly higher than in other strains (P <0.05). The Aa-specific IgG levels in the DSS Aa-inoculated group were significantly higher than in its control group (P <0.05). Only FHH rats showed Aa disease-associated bone loss (P = 0.0021).


CONCLUSIONS
Aa colonized and caused more disease in FHH rats than in the other rat strains. The rat strains each responded differently to the same Aa strain.
Schreiner
Helen
H
Department of Oral Biology, New Jersey Dental School, University of Medicine and Dentistry of New Jersey, Newark, NJ 07103, USA.
Markowitz
Kenneth
K
Miryalkar
Manjula
M
Moore
Danielle
D
Diehl
Scott
S
Fine
Daniel H
DH
D000189:Actinobacillus Infections / Q000276:immunology / Q000382:microbiology*; D016976:Aggregatibacter actinomycetemcomitans / Q000502:physiology*; D016301:Alveolar Bone Loss / Q000276:immunology / Q000382:microbiology* / Q000473:pathology; D000539:Alveolar Process / Q000473:pathology; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood / Q000276:immunology*; D058491:Bacterial Load; D001431:Bacteriological Techniques; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D008297:Male; D008963:Molar / Q000473:pathology; D010865:Pilot Projects; D051381:Rats; D011914:Rats, Inbred BN; D020303:Rats, Inbred Dahl; D011919:Rats, Inbred Strains; D013047:Specific Pathogen-Free Organisms; D013997:Time Factors; D019237:Tooth Cervix / Q000473:pathology
D000907:Antibodies, Bacterial; D007074:Immunoglobulin G