IS1111 insertion sequences of Coxiella burnetii: characterization and use for repetitive element PCR-based differentiation of Coxiella burnetii isolates.
BACKGROUND
Coxiella burnetii contains the IS1111 transposase which is present 20 times in the Nine Mile phase I (9Mi/I) genome. A single PCR primer that binds to each IS element, and primers specific to a region approximately 500-bp upstream of each of the 20 IS1111 elements were designed. The amplified products were characterized and used to develop a repetitive element PCR genotyping method.


RESULTS
Isolates Nine Mile phase II, Nine Mile RSA 514, Nine Mile Baca, Scottish, Ohio, Australian QD, Henzerling phase I, Henzerling phase II, M44, KAV, PAV, Q238, Q195 and WAV were tested by PCR and compared to 9Mi/I. Sequencing was used to determine the exact differences in isolates which lacked specific IS elements or produced PCR products of differing size. From this data, an algorithm was created utilizing four primer pairs that allows for differentiation of unknown isolates into five genomic groups. Additional isolates (Priscilla Q177, Idaho Q, Qiyi, Poker Cat, Q229 and Q172) and nine veterinary samples were characterized using the algorithm which resulted in their placement into three distinct genomic groups.


CONCLUSIONS
Through this study significant differences, including missing elements and sequence alterations within and near IS element coding regions, were found between the isolates tested. Further, a method for differentiation of C. burnetii isolates into one of five genomic groups was created. This algorithm may ultimately help to determine the relatedness between known and unknown isolates of C. burnetii.
Denison
Amy M
AM
Coordinating Center for Infectious Diseases, Division of Viral and Rickettsial Diseases, Rickettsial Zoonoses Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA. crk6@cdc.gov
Thompson
Herbert A
HA
Massung
Robert F
RF
D015373:Bacterial Typing Techniques; D016997:Coxiella burnetii / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D004251:DNA Transposable Elements; D004269:DNA, Bacterial / Q000235:genetics; D016680:Genome, Bacterial; D006801:Humans; D016133:Polymerase Chain Reaction; D011778:Q Fever / Q000382:microbiology*; D019895:Transposases / Q000235:genetics*
D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D019895:Transposases