Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0014118 (endocarditis)
 15,629 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Bartonella endocarditis is a severe disease for which blood cultures frequently remain negative. We tested three PCR assays by using specimens of serum sampled early during the disease from 43 patients diagnosed in our laboratory as having Bartonella endocarditis on the basis of serological, culture, and/or valvular molecular detection. We tested a two-step nested PCR (TSN-PCR), a one-step nested PCR (OSN-PCR) with a regular thermal cycler, and a one-step nested PCR with the LightCycler (LCN-PCR). These assays were performed with primers derived from the riboflavin synthase-encoding gene ribC, never before amplified in our laboratory. Due to contamination of negative controls, the results of the TSN-PCR were not interpretable, and this technique was no longer considered. The LCN-PCR had a specificity of 100% and a sensitivity of 58.1%, higher than those of the OSN-PCR (18.6%; P < 0.01) and prolonged blood culturing (7.1%; P < 0.01). The LCN-PCR results correlated strictly with those of other direct diagnostic tests, when available, and identified the causative species for six patients previously diagnosed on the basis of serological analysis only. The efficacy of the LCN-PCR was not influenced by antibiotics (P = 0.96) but was altered by prolonged storage of serum specimens at -20 degrees C (P = 0.04). Overall, the LCN-PCR is specific and more sensitive than traditional methods (i.e., culturing and/or PCR with EDTA-treated blood). It can easily be applied to the diagnosis of patients with suspected Bartonella endocarditis, especially when only serum is available.
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PMID:Diagnosis of Bartonella endocarditis by a real-time nested PCR assay using serum. 1262 10

Bartonella koehlerae is reported for the first time to be a human pathogen that causes culture-negative endocarditis. It is also shown that this species, isolated twice before from domestic cats, can be recovered as well from a stray cat population in Israel. This work follows a recent report of the same case in which the causative agent was misidentified as B. henselae, based on serology and PCR-restriction fragment length polymorphism (RFLP) analysis (A. Schattner, O. Zimhony, B. Avidor, and M. Gilad, Lancet 361:1786, 2003). B. koehlerae was identified in the valvular tissue of an endocarditis patient by DNA sequencing of the PCR products of two Bartonella genes: the genes for citrate synthase (gltA) and riboflavin synthase (ribC). The commonly used PCR-RFLP analysis of the TaqI-digested gltA PCR product did not distinguish between B. koehlerae and B. quintana or between B. elizabethae and B. clarridgeiae. PmlI digestion of the gltA amplification product failed to differentiate between B. quintana, B. clarridgeiae, and B. elizabethae. RFLP analysis of the heat shock protein (htrA) gene by TaqI digestion misidentified B. koehlerae as B. henselae. However, RFLP analysis of the ribC PCR product, digested with TaqI, was able to distinguish between the human endocarditis-associated Bartonella species tested, B. henselae, B. quintana, B. elizabethae, and B. koehlerae, as well as between the cat-associated Bartonella species, B. henselae and B. clarridgeiae. Given the expanding number of Bartonella species emerging as human pathogens, it is suggested that PCR-RFLP analysis for the diagnosis of Bartonella infections target several genes and be coupled with DNA sequencing to avoid species identification.
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PMID:Bartonella koehlerae, a new cat-associated agent of culture-negative human endocarditis. 1529 84