ABSTRACT
Introduction: Early onset bacterial sepsis is a feared complication of the newborn. A large proportion of infants admitted to the neonatal intensive care unit [NICU] for suspected sepsis receive treatment with potent systemic antibiotics while a diagnostic workup is in progress. The gold standard for detecting bacterial sepsis is blood culture. However, the sensitivity of blood culture is suspected to be low. Therefore, the diagnosis of sepsis is often based on the development of clinical signs, in combination with laboratory tests. Immunological assays of CD11b expression on peripheral blood neutrophil and serum E-selectin and molecular assays for the detection of bacterial DNA in the blood represent possible new diagnostic tools for early and rapid diagnosis of neonatal sepsis
Aim: This study aimed at comparing the valuability of bacteriological diagnosis of neonatal sepsis by blood culture technique and indirect methods of diagnosis
Methods: Bacteriological diagnosis of neonatal sepsis by blood culture technique and comparing it to indirect methods of diagnosis by assaying of neutrophil CD11b expression level by flowcytometry, estimation of elevated concentrations of serum E-selectin by enzyme linked immunosorbant assay and detection of bacterial DNA in blood samples by broad range PCR
Results: The infected group represented 60%. Klebsiella pneumoniae were the commonest isolated organisms in culture positive cases. CD11b expression assay by flowcytometry in infected and non infected cases showed a sensitivity of 77.8%, specificity of 100%, a PPV of 100% and a NPV of 75.1%. Serum E-selectin assay by ELISA in infected and non infected cases showed a sensitivity of 57.8%, specificity of 83.3%, a PPV of 83.8% and a NPV of 56.8%. PCR results had 88.5% sensitivity, 89.5% specificity, a PPV of 92% and a NPV of 85%
Conclusion: There is a need for CD11b expression assay, serum E-selectin level estimation and PCR as methods to quickly point out the infants with sepsis so such methods can be used as a supplement to traditional blood culture in diagnosis of neonatal sepsis and provide better diagnostic values as regarding rapidity of obtaining results and higher sensitivities and specificities, besides combination of multiple methods may provide more ease and accuracy for diagnosis
ABSTRACT
Background: Systemic fungal infection remains a major cause of morbidity and death in patients undergoing treatment for cancer. Therefore sensitive, quick and inexpensive testes essential for diagnosing systemic fungal infecton. In our labs we commonly diagnose fungemia using convential blood culture. Convential blood culture is time-consuming and with poor sensitivity. Polymerase chain reaction [PCR] has the potential to provide a quick and inexpensive method for diagnosis of systemic fungal infection. We studied these two different methods in the diagnosis of systemic fungal infection. Aim : The aims of this study were to compare convential blood culture and PCR in the diagnosis of systemic fungal infection and to determine sensitivity, specificity of PCR
Methods: Blood samples were collected from patients in Oncology center clinically suspected of systemic fungal infection. Whole blood samples were collected. First part of the sample was inoculated into blood culture bottle and the other part of the sample was subjected to DNA extraction and PCR which was carried out using pan-fungal primers
Results: One hundred thirty three samples were collected. Seventy six positive samples were positive by conventional blood culture bottle and/or PCR. Nine samples were positive by conventional blood culture. They yielded Candida species, these samples were also positive by PCR. The other 67 samples were positive by PCR reaction only using panfungal primer. The most common isolated organisms by conventional blood culture bottle were Candida albicans six isolates [66.7%]. Three non albicans Candida isolates [C. tropicalis, C. krusi and C. dubliniensis] were isolated. Using blood culture as gold test, sensitivity of PCR was 100%, and specificity was 46%. The most common underlying malignancy was leukaemia [84.2%], followed by lymphoma [13.1%], and solid tumours [2.6%]
Conclusion: The application of PCR technology directly to the whole blood samples will allow early and accurate diagnosis of systemic fungal infection?