Emerging Blood Culture Technologies for Isolation of Blood Pathogens at Clinical Microbiology Laboratories

Abstract

Bloodstream infections (BSIs) are important cause of morbidity and mortality in patients. Around 20 million cases of severe sepsis arise each year worldwide. Rapid and accurate identification of the etiologic pathogen is crucial to be able to initiate pathogen specific antibiotic therapy and decrease mortality rates, and for reducing length of hospitalization and hospital costs. These identification techniques are applied on various emerging blood culture techniques. This review summarized and presented the currently available technologies and different strategies of conventional laboratory diagnostic steps for blood stream infection. Based on their capability these techniques can be manual, semi-automated or fully automated. Considering the importance of blood cultures in diagnosis and management of bloodstream infections, it is prudent and relevant to understand the principles, technical requirements and limitations of these technologies. Nowadays, there are various emerging blood culture techniques for the diagnosis of blood stream infections and drug susceptibility testing. Among these are API, the BBL systems, the BACTEC systems, the VITEK systems, the BacT/Alert, the BacT/Alert 3D and the Versa TREK system can be mentioned. These systems depend on various detection principles and cultural environments to detect microorganisms. The selection of instrument for the identification and susceptibility testing of bacteria in diagnostic laboratory rely on speed, accuracy, ease of use and cost factors. All marketed identification systems are based on one of five different technologies or a combination of them. These include pH-based reactions, enzyme-based reactions, utilization of carbon sources, visual detection of bacterial growth, or detection of volatility fatty acids.