Identification of serotypes of Actinobacillus actinomycetemcomitans by multiplex PCR

Objective To identify the clinically isolated Actinobacillus actinomycetemcomitans(Aa)serotypes by multiplex PCR,and analyze the relationship between serotypes and flp-1 classes.Methods Sixty Aa strains were isolated from 24 patients and serotyped by multiplex PCR with primers specific for serotypes a to e,and normal PCR with primers specific for serotype f.The association between serotypes and genotypes of flp-1 was also analyzed.Results The overall prevalence of serotypes was:c,63.33%;e,23.3%;b,6.67%;and a,f,3.33%,respectively.Serotype d was not observed among the clinical isolates.Among the 24 patients,15 patients carried serotype c,3 patients carried b,2 patients carried a,2 patients carried e,and 2 patients carried f.flp-1 Class Ⅰ was correlated with serotype a.Among 40 strains of flp-1 Class Ⅱ,38 strains were serotype c.Strains of flp-1 Class Ⅳ were serotype b.Nine strains were serotype e among 11 strains of flp-1 Class Ⅴ.Serotypes of flp-1 Class Ⅵ strains were b.Conclusion The most prevalent serotype is c.Serotypes correlate with flp-1 classes in the majority of strains.