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Correspondence to Author: Dr Grace Olive, Dr G Pavani 

Assistant professor.
professor & HOD, Dept of Microbiology, AIMSR, Jubilee hills, Hyderabad- INDIA

DOI: 10.52338/tjocmb.2026.5783

Abstract:

Background: Blood culture remains the gold standard for diagnosing bloodstream infections and guiding antimicrobial therapy; however, contamination during sample collection continues to compromise diagnostic accuracy and patient management. This prospective observational study was conducted over six months in the Department of Microbiology of a tertiary care teaching hospital to evaluate the burden and impact of false-positive blood cultures.
Results: A total of 670 blood culture samples were processed using the automated BACT/ALERT system, followed by organism identification and antimicrobial susceptibility testing using standard microbiological methods and the VITEK 2 system. Among the processed samples, 44 (6.6%) were identified as contaminants. Micrococcus species and Coagulase-negative Staphylococci were the predominant isolates, each accounting for 40.9% of contaminants, followed by Gram-positive bacilli. Contamination was most frequently observed in emergency and critical care settings. False-positive blood cultures contributed to diagnostic uncertainty, repeated sampling, delayed confirmation of true pathogens, unnecessary empirical antibiotic exposure, increased laboratory workload, prolonged hospitalization, and additional healthcare costs. The study highlights the importance of strict aseptic blood collection practices, continuous staff training, diagnostic stewardship, and regular surveillance to reduce contamination rates and improve overall quality patient care.

Keywords: Contaminants,Improper Blood Collection,False Positive Blood Culture,High Risk Areas,Diagnostic Stewardship.

Citation:

Dr Grace Olive, False Positive Blood Cultures And Their Impact On Quality Care. The Journal of Clinical Microbiology 2026.