COMPARATIVE STUDY ON CONVENTIONAL BLOOD CULTURE AND AUTOMATED BLOOD CULTURE (BACTEC 9050) IN THE EARLY DETECTION OF BACTERIAL ISOLATES IN TERTIARY CARE HOSPITAL OF KUMAUN REGION

BACKGROUND Blood stream infections range from self-limiting infections to life threatening sepsis that require rapid and aggressive antimicrobial treatment. Timely detection and identification of blood-borne pathogens would be a useful guide for clinicians in initiating the empiric antibiotic therapy. Objectives-To evaluate the capability, efficiency and reliability of automated blood culture methods (BACTEC 9050) in comparison to conventional blood culture for detection of bacterial isolates in clinically suspected cases of septicaemia. METHODS All the blood culture samples (in duplicate), from 2 different sites, at 2 different times, 30 minutes apart, were taken from suspected cases of septicaemia consecutively during study period (September 2016 to June 2017). Samples were subjected to conventional blood culture and BACTEC 9050 culture system. RESULTS Out of 254 suspected cases of septicaemia, 93 (36.6%) cases were culture positive. Among these, 60% were positive with both methods while 36.5% were positive on BACTEC culture only. Out of 93 positive cases, a total of 100 isolates comprising of grampositive bacteria (62%), gram-negative bacteria (36%) and Candida sp. (2%) were detected. BACTEC 9050 detected all positive samples in within 24 hours while Conventional method detected none within 24 hrs, 25.4% within 48 hours, and 84.7% within 86 hours. Among gram-positive bacteria, predominant isolates were Coagulase Negative Staphylococcus (41%) followed by Enterococcus (9%). Among gram-negative isolates, 14% were Pseudomonas sp. followed by 10% Acinetobacter sp. BACTEC 9050 was observed to be more sensitive (94.9%) in comparison to conventional blood culture. Mean time of detection was significantly less (11.3 hours) with the BACTEC 9050 than with conventional method (61.7 hours). CONCLUSIONS BACTEC 9050 proved to be a reliable, fast technique with high sensitivity and specificity in identification of the blood stream pathogens in blood culture in comparison to conventional culture methods.