Acta Scientific Microbiology (ISSN: 2581-3226)

Research Article Volume 4 Issue 9

The Accuracy of Non-Conventional Methods Compared to Conventional Methods for Diagnosis of Bloodstream Infections

Raghdah A Abdulmajeed1, Asif Jiman-Fatani2,4 and Dalia EL-Hossary3*

1Regional lab Makkah, Ministry of Health, Makkah, Kingdom of Saudi Arabia
2Department of Medical Microbiology and Parasitological, Faculty of Medicine, King Abdulaziz University, Jeddah, Kingdom of Saudi Arabia
3Department of Medical Microbiology and Immunology Department, Faculty of Medicine, Zagazig University, Egypt
4Clinical and Molecular Microbiology Laboratory, King Abdulaziz University Hospital, Jeddah, Kingdom of Saudi Arabia

*Corresponding Author: Dalia EL-Hossary, Department of Medical Microbiology and Immunology Department, Faculty of Medicine, Zagazig University, Egypt.

Received: July 19, 2021 ; Published: August 12, 2021


Bloodstream infections (BSI) are severe infections leading to potentially life-threatening illnesses that require quick diagnosis, which ensures that the patient is administered appropriate antimicrobials and proper care. The identification of microorganisms from positive blood cultures by a conventional method usually takes several days. In this study, we investigated the performance of three new rapid technologies viz. MALDI-TOF, FilmArray (BioFire), and Nanosphere for their ability to identify the microorganisms present in positive blood culture bottles directly, before subculture, and compare it with VITEK 2 method (gold standard). A total of 1,766 microorganisms were isolated in this study. The MALDI-TOF identified 437 Gram-positive bacteria out of 443 Gram-positive isolates from a colony subculture, and showed sensitivity, Positive predictive value (PPV), and accuracy of 98.7%, 99%, and 98%, respectively. MALDI-TOF correctly identified 403 Gram-negative bacteria (out of 407) with 99% sensitivity, PPV was 100%, and 99% accuracy. The Nanosphere BC-GN assay accurately identified 343 Gram-negative bacteria out of 407 Gram-negative bacteria with sensitivity, PPV, and accuracy of 84.3%, 99%, and 83%, respectively. The BioFire system helped identify 24 microorganisms that commonly cause sepsis, pooled together: 8 Gram-positive strains, 11 Gram-negative strains, 5 Candida species, and three antimicrobial-resistance genes. In our study, out of 443 Gram-positive bacteria, 435 were identified by BioFire with sensitivity, PPV, and accuracy of 98.2%, 99%, and 98.2%, respectively. BioFire could also identify 59 yeast isolates out of 66 with 89% sensitivity, 100% PPV, and 89% accuracy. In conclusion, these new technologies provided fast (in some cases, 48 hours earlier than VITEK 2) and reliable results. Adopting of these technologies should be encouraged in the microbiology labs of the hospitals.

Keywords: Bloodstream Infection; VITEK 2; MALDI-TOF; BioFire; Nanosphere


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Citation: Dalia EL-Hossary., et al. “The Accuracy of Non-Conventional Methods Compared to Conventional Methods for Diagnosis of Bloodstream Infections ”. Acta Scientific Microbiology 4.9(2021): 69-80.


Copyright: © 2021 Dalia EL-Hossary., et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.


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