Update on blood cultures: how to obtain, process, report, and interpret

Abstract

The detection and identification of microorganisms circulating in the bloodstream of patients is arguably one of the most important functions of the clinical microbiology laboratory. Effective implementation of this function requires careful consideration of specimen collection and processing, culture techniques, result reporting, and, perhaps most importantly, result interpretation by the physician. The purpose of this review is to provide a synopsis of the current state of the art for each of these areas, with the intention of providing adequate information to enable clinical laboratory personnel and physicians to critically evaluate and, if required, improve their current blood culture practices.

Comprehensive Analysis of Blood Cultures Using BacT/Alert 3D FA Plus and FN Plus Media

“…Sometimes classification of the isolate as a true pathogen or a contaminant is difficult, especially with CoNS [1,9,15]. An experienced ED physician reviewed the medical records and categorized the isolates into two groups, clinically significant or contaminant.…”

“…Growth of Bacillus spp., Corynebacterium spp., Propionibacterium spp., and Micrococcus spp. was regarded as skin contamination, regardless of a positive result [1,9]. TTD was defined as the time interval between the entry of the bottles and a positive signal in the BacT/ Alert 3D system.…”

“…Early detection of microorganisms is a highlight of the automated continuous blood culture systems. Rapid detection and early reports of blood culture are crucial for treating sepsis patients and for reducing hospital stays [1,8,9]. Therefore, detection time is an important indicator of performance in the evaluation of blood culture systems.…”

Diagnostična vrednost označevalcev pri sepsi

“…Za večino baterijskih povzročiteljev znaša mediana časa do pozitivnosti hemokultur 12-36 ur, medtem ko je čas za določene bakterije in glive daljši. Pri uporabi tradicionalnih mikrobioloških metod potrebujemo za prepoznavanje povzročitelja sepse in opredelitev njegove občutljivosti na protimikrobna zdravila nadaljnjih 48-72 ur (14)(15)(16).…”

Added value of multi-pathogen probe-based real-time PCR SeptiFast in the rapid diagnosis of bloodstream infections in patients with bacteraemia

“…Delayed diagnosis and inappropriate antibiotic therapy are associated with increased morbidity and mortality in intensive care patients (Garnacho-Montero et al, 2003;Zubert et al, 2010). Blood culture (BC) represents the current gold standard for the aetiological diagnosis of bloodstream microbial pathogens (Kirn & Weinstein, 2013). However, BC is affected by low sensitivity, particularly when antibiotics have already been administered (Glerant et al, 1999); moreover, prolonged incubation times for fungi and fastidious micro-organisms may have an impact on early management of patients (Bauer & Reinhart, 2010).…”