Molecular Detection by PCR

Detection of Bartonella spp. by PCR.

 

Fluid aspirate from wound, sample of pus, fluid and/or tissue from lymph nodes, heart valve biopsy, synovial joint fluid.

 

A swab or fluid aspirate from suspected area of infection and whole blood. Tissue biopsy samples should be collected from lymph nodes or heart valve samples from cases of culture-negative endocarditis, placed in a screw-cap jar or sample bottle, and frozen immediately. CSF is accepted for testing, however please note that these specimen are not ideal. Dry swabs are not acceptable for testing; any swabs sent must be supplied in appropriate storage medium. At least 1 mL of fluid sample is required for submission, or at least 1 mL of specimen such as swab samples re-suspended in appropriate transport medium. It is preferable if all samples are supplied in screw-capped tubes made of freeze-thaw and shatter-resistant plastic.

No further processing required. Store samples refrigerated or frozen until shipped for testing. Ship frozen samples on dry ice, and refrigerated samples on cold packs.

Shipping of specimens shall be done by a TDG certified individual in accordance with TDG regulations. For additional information regarding classification of specimens for the purposes of shipping, consult either Part 2 Appendix 3 of the TDG Regulations or section 3.6.2 of the IATA Dangerous Goods Regulations as applicable.

Clinical manifestations of Bartonella henselae infection, also referred to as “Cat scratch disease” (CSD), may include localized infections such as sub-acute regional lymphadenopathy, skin lesions, musculoskeletal lesions, culture-negative endocarditis, and uveitis and retinitis; however systemic manifestations are also common resulting in symptoms of fever, meningitis, osteomyelitis, arthritis, and bacillary angiomatosis.

 

Completed Special Bacteriology requisition form detailing all patient information and relevant clinical information. If possible, attach lab results that have already been done at local or provincial laboratories.

 

Due to the fact that a Bartonella spp. infection can result in localized and systemic manifestations, it is difficult to accurately detect the infectious agent unless the appropriate specimens are submitted for testing. Please only submit the listed specimen types and supplement with clinical information leading to suspicion of infection.

 

DNA from all Bartonella samples received at the NML for PCR testing is initially extracted using a commercially-available kit. The PCR reactions performed are as follows:

1. A PCR to detect the human b-globin gene to test for DNA quality and integrity
2. A PCR to detect the conserved rpoB gene of the Bartonella genus
3. A PCR to detect a specific Bartonella spp. heat shock protein

A sample is interpreted to be positive for Bartonella spp. if the PCR for the rpoB gene, the heat shock protein, or both, is positive. The positive PCR products are sequenced for confirmation and species determination. A negative result does not eliminate the possibility of a Bartonella infection but will only rule out a potential infection of the relative area of specimen origin. As with any laboratory test, the results of the test should be interpreted with consideration of all of the laboratory and clinical findings available. The PCR for the human b-globin gene must also be positive.

12 calendar days. Please note that during times when large numbers of samples are received or if tests must be repeated the turnaround time may be longer.

 

1. Chomel B, Boulouis HJ, Maruyama S, Breitschwerdt EB. 2006. Bartonella Spp. in pets and effect on human health. Emerg. Infect. Dis. (12):389-394.
2. Raoult D. 2007. From cat scratch disease to Bartonella henselae infection. Clin. Infect. Dis. (45):1541-1542.