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1.  Higher blood volumes improve the sensitivity of direct PCR diagnosis of blood stream tuberculosis among HIV-positive patients: an observation study 
Background
Blood stream tuberculosis (TB), caused by Mycobacterium tuberculosis (MTB) is common among HIV-positive patients, turning rapidly fatal unless detected and treated promptly. Blood culture is currently the standard test for the detection of MTB in whole blood but results take weeks; patients deteriorate markedly and often die before a diagnosis of blood stream TB is made. Rapid molecular tests on whole blood, with potential for same day diagnosis of blood stream TB usually show low sensitivity due to the problem of insufficient MTB DNA template when extraction is performed directly on low blood volumes. This study assessed the influence of blood volume on the sensitivity of a HyBeacon PCR assay-the FluoroType® MTB (Hain Lifescience, Nehren, Germany) on direct detection of MTB in whole blood.
Methods
Prospective recruitment of HIV-positive patients with clinical suspicion of blood stream TB but not on anti-TB or HIV drug treatment was done. Venous blood samples were collected and DNA extracted using the MolYsis (Molzym, Bremen, Germany) methods; for study A, from duplicate 1 ml (42 patients) and for study B (31 patients) from 9 ml EDTA blood samples. The FluoroType® MTB PCR assay targeting an IS6110 sequence was performed and results compared with blood culture.
Results
The diagnostic sensitivity and specificity of the FluoroType® MTB PCR in study A was 33% and 97%, respectively. Corresponding values in study B were 71% and 96%, respectively. In both studies, one case each of blood culture-negative blood stream TB was detected with the FluoroType® MTB PCR assay. The median time to positivity of blood culture was 20.1 (range 12–32) for study A and 19.9 days (range 15–30) for study B.
Conclusion
Larger blood volumes (9 ml) improved and gave acceptable sensitivity of direct PCR diagnosis of blood stream TB.
doi:10.1186/s12879-015-0785-3
PMCID: PMC4326319  PMID: 25656799
Tuberculosis; Blood stream; Direct; Real time; PCR Diagnosis
2.  Monitoring of Patients Supported by Extracorporeal Membrane Oxygenation for Systemic Infections by Broad-Range rRNA Gene PCR Amplification and Sequence Analysis 
Journal of Clinical Microbiology  2014;52(1):307-311.
The rRNA gene PCR and sequencing test, SepsiTest, was compared with blood culture (BC) regarding the diagnosis of pathogens in 160 blood samples drawn from 28 patients during extracorporeal membrane oxygenation. With 45% of positive samples, SepsiTest was 13 to 75 h faster than BC. SepsiTest indicated bacteremias in 25% of patients who were BC negative.
doi:10.1128/JCM.02493-13
PMCID: PMC3911412  PMID: 24153127
3.  Evaluation of Commercial Universal rRNA Gene PCR plus Sequencing Tests for Identification of Bacteria and Fungi Associated with Infectious Endocarditis▿ 
Journal of Clinical Microbiology  2011;49(8):2919-2923.
Two new commercially available universal rRNA gene PCR plus sequencing tests, SepsiTest and universal microbe detection (UMD; Molzym, Bremen, Germany), were evaluated using blood specimens and heart valves from 30 patients with suspected infectious endocarditis (IE). The sensitivity of PCR (85%) was nearly twice as high as that of culture (45%), which in 10/20 IE cases presumably stayed negative as a consequence of growth inhibition of the pathogens by antibiotics. Further, PCR provided the basis for reclassification of 5/10 non-IE cases into IE cases. Culture-negative infections were identified by PCR, including single infections due to streptococci and Gram-negative bacteria (Escherichia coli, Haemophilus parainfluenzae) and mixed infections involving two Gram-positive bacteria or Candida spp. with Gram-positive bacteria. The new commercial tests proved to be of value for the rapid diagnosis of IE, particularly in cases of culture-negative infections. Issues regarding the feasibility of these tests for routine use are discussed.
doi:10.1128/JCM.00830-11
PMCID: PMC3147771  PMID: 21715592
4.  Detection of “Candidatus Neoehrlichia mikurensis” in Two Patients with Severe Febrile Illnesses: Evidence for a European Sequence Variant▿  
Journal of Clinical Microbiology  2010;48(7):2630-2635.
Recently, a new genus of Anaplasmataceae termed “Candidatus Neoehrlichia” was discovered in ticks and rodents. Here, we report on two patients who suffered from febrile bacteremia due to “Candidatus Neoehrlichia mikurensis” associated with thrombotic or hemorrhagic events. 16S rRNA and groEL gene sequencing provided evidence of three groups of sequence variants.
doi:10.1128/JCM.00588-10
PMCID: PMC2897504  PMID: 20519481
5.  Diagnosis of Bacteremia in Whole-Blood Samples by Use of a Commercial Universal 16S rRNA Gene-Based PCR and Sequence Analysis▿  
Journal of Clinical Microbiology  2009;47(9):2759-2765.
In a prospective, multicenter study of 342 blood samples from 187 patients with systemic inflammatory response syndrome, sepsis, or neutropenic fever, a new commercial PCR test (SepsiTest; Molzym) was evaluated for rapid diagnosis of bacteremia. The test comprises a universal PCR from the 16S rRNA gene, with subsequent identification of bacteria from positive samples by sequence analysis of amplicons. Compared to blood culture (BC), the diagnostic sensitivity and specificity of the PCR were 87.0 and 85.8%, respectively. Considering the 34 BC-positive patients, 28 were also PCR positive in at least one of the samples, resulting in a patient-related sensitivity of 82.4%. The concordance of PCR and BC for both positive and negative samples was (47 + 247)/342, i.e., 86.0%. In total, 31 patients were PCR/sequencing positive and BC negative, in whom the PCR result was judged as possible or probable to true bacteremia in 25. In conclusion, the PCR approach facilitates the detection of bacteremia in blood samples within a few hours. Despite the indispensability of BC diagnostics, the rapid detection of bacteria by SepsiTest appears to be a valuable tool, allowing earlier pathogen-adapted antimicrobial therapy in critically ill patients.
doi:10.1128/JCM.00567-09
PMCID: PMC2738079  PMID: 19571030

Results 1-6 (6)