Comparative study of manual conventional blood cultures versus automated blood culture system in cases of septicemia

Abstract

: Blood cultures are a proven gold standard method for the identification of causative agents of bloodstream infections. Identification of causative organism along with antibiotic susceptibility plays a pivotal role in proposing suitable antibiotic therapy. Automated blood culture systems show improved monitoring of blood cultures by reducing the time and by ensuring more accurate results when compared to the conventional blood culture system. To isolate the organism from given blood samples of a suspected case of septicemia and to compare the results of conventional and automated blood culture systems and to study the antimicrobial susceptibility pattern of the pathogens isolated. A prospective study of 6 months period was conducted among 100 subjects attending the Department of Microbiology in a tertiary care hospital. Subjects with symptoms and signs of septicemia were included. 25ml of venous blood was drawn aseptically from the venipuncture site, of which 5ml of blood was inoculated into 50ml of Brain Heart Infusion bottle in conventional blood culture system and 10ml each into aerobic and anaerobic BACTEC PLUS bottle in Automated blood culture system BACTEC FX40. Overall, 48% and 60% of the samples revealed positive growth by the conventional and automated blood culture system BACTEC FX40, respectively. Gram Positive Cocci were 52.08% and Gram Negative Bacilli were 47.91% isolated by conventional blood culture system, whereas automated blood culture system BACTEC FX40 isolated 45% and 55%, respectively. Isolates were detected within 24-48hrs and 12-24 hrs by conventional and automated blood culture systems, respectively. The anti-microbial susceptibility pattern of the pathogens isolated was also recorded by Kirby Bauer disc diffusion method of antimicrobial susceptiblity testing. Automated blood culture systems are a trustworthy substitute to conventional blood culture systems. The automated blood culture systems being more sensitive and rapid in detecting septicemia in subjects acts as an appropriate means for the initial identification and detection of blood pathogens and improved provision of antimicrobial therapeutic options for septic Patients especially in Critical Care and Intensive Care Units where positive culture reporting is crucial.

A Comparative Study of Conventional and Automated Blood Culture System in Adult Patients

“…[12] In this present study Staphylococcus aureus remained predominant among gram positive organisms followed by Escherichia coli which remained predominant among gram negative organisms in the automated blood culture method. This study correlated with the study conducted by Saher L. et al [13] and Sultana Q. et al in 2016 [14] where a predominance of gram positive isolates like Staphylococcus aureus was observed. The present study also showed that automated blood culture system is a better method for isolating and identifying microorganisms like Salmonella typhi.…”

A novel Colorcult hemoculture in early diagnosis of blood stream infection: A boon in meagre resources

“…Bac T/ALERT 3D automated method detects earlier and studies recorded time to detection (TTD) by this method was 15.83 hours, but reported more contaminants compared to conventional method [11]. Major causes of false positive instrument signals include samples with leukocytosis, over -filled bottles and temperature fluctuation during incubation.…”