Evaluation of conventional and real-time PCR assays for detection and differentiation of Spotted Fever Group Rickettsia in dog blood.
Spotted Fever Group Rickettsia is important cause of emerging and re-emerging infectious disease in people and dogs. Importantly, dogs can serve as sentinels for disease in people. Sensitive and specific diagnostic tests that differentiate among species of infecting Rickettsia are needed. The objective of this study was to develop a sensitive and specific PCR that differentiates SFG Rickettsia infecting dog blood. Conventional and real-time PCR assays were developed using primers that targeted a small region of the ompA gene. Their sensitivity, determined by testing a cloned target sequence in the presence of host DNA, was 15-30 and 5 copies of DNA, respectively. Testing of Rickettsia cultures and analysis of Rickettsia gene sequences deposited in GenBank verified DNA could be amplified and used to differentiate species. DNA from the blood of infected dogs was also tested. Importantly, Rickettsia DNA was detected before seroconversion in some dogs. The species of infecting Rickettsia was also identified. We conclude these assays may assist in the timely diagnosis of infection with SFG Rickettsia. They may also facilitate the discovery of novel SFG Rickettsia infecting dogs, and in the investigation of dogs as sentinels for emerging rickettsioses.
Kidd
L
L
Intracellular Pathogens Research Laboratory, Center for Comparative Medicine and Translational Research, North Carolina State University College of Veterinary Medicine, Raleigh, NC 27606, USA. lkidd@westernu.edu
Maggi
R
R
Diniz
P P V P
PP
Hegarty
B
B
Tucker
M
M
Breitschwerdt
E
E
D000818:Animals; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics; D001483:Base Sequence; D001907:Boutonneuse Fever / Q000175:diagnosis / Q000382:microbiology / Q000662:veterinary*; D017931:DNA Primers; D004269:DNA, Bacterial / Q000097:blood / Q000737:chemistry / Q000235:genetics; D004197:Disease Reservoirs / Q000662:veterinary; D004283:Dog Diseases / Q000097:blood / Q000175:diagnosis* / Q000382:microbiology; D004285:Dogs; D005784:Gene Amplification; D006801:Humans; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction / Q000379:methods / Q000662:veterinary*; D012281:Rickettsia / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D020114:Rickettsia conorii / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D012284:Rickettsia rickettsii / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D012373:Rocky Mountain Spotted Fever / Q000175:diagnosis / Q000382:microbiology / Q000662:veterinary*; D012680:Sensitivity and Specificity; D018571:Sentinel Surveillance / Q000662:veterinary; D013045:Species Specificity
D001425:Bacterial Outer Membrane Proteins; D017931:DNA Primers; D004269:DNA, Bacterial; C078167:OMPA outer membrane proteins