Jundishapur J Microbiol. 2016 January; 9(1): e29766. doi: 10.5812/jjm.29766 Research Article Published online 2016 January 2. A Multicenter Evaluation of Blood Culture Practices, Contamination Rates, and the Distribution of Causative Bacteria 1,* 1 2 3 4 Mustafa Altindis, Mehmet Koroglu, Tayfur Demiray, Tuba Dal, Mehmet Ozdemir, Ahmet 5 1 4 6 7 8 Zeki Sengil, Ali Riza Atasoy, Metin Turan, Aysegul Copur Cicek, Gulfem Ece, Selcuk Kaya, 9 9 10 11 12 Meryem Iraz, Bilge Sumbul Gultepe, Hakan Temiz, Idris Demirkan, Sebahat Aksaray, 13 14 15 16 17 Yeliz Cetinkol, Idris Sahin, Huseyin Guducuoglu, Abdullah Kilic, Esra Kocoglu, Baris 18 19 Gulhan, and Oguz Karabay 1Department of Clinical Microbiology, Faculty of Medicine, Sakarya University, Sakarya, Turkey 2Department of Clinical Microbiology, Training and Research Hospital, Sakarya University, Sakarya, Turkey 3Department of Clinical Microbiology, School of Medicine, Yildirim Beyazit University, Ankara, Turkey 4Department of Clinical Microbiology, Meram Medical Faculty Hospital, Necmettin Erbakan University, Konya, Konya 5Department of Medical Microbiology, Medical Faculty, Medipol University, Istanbul, Turkey 6Department of Clinical Microbiology, School of Medicine, Recep Tayyip Erdogan University, Rize, Turkey 7Department of Clinical Microbiology, School of Medicine, Izmir University, Izmir, Turkey 8Department of Clinical Microbiology, School of Medicine, Izmir Katip Celebi University, Izmir, Turkey 9Department of Clinical Microbiology, School of Medicine, Bezmi Alem University, Istanbul, Turkey 10Department of Clinical Microbiology, Diyarbakir Training and Research Hospital, Diyarbakir, Turkey 11Department of Clinical Microbiology, School of Medicine, Dicle University, Diyarbakir, Turkey 12Department of Clinical Microbiology, Haydarpasa Numune Hospital, Istanbul, Turkey 13Department of Clinical Microbiology, School of Medicine, Ordu University, Ordu, Turkey 14Department of Clinical Microbiology, School of Medicine, Duzce University, Duzce, Turkey 15Department of Clinical Microbiology, School of Medicine, Yuzuncuyil University, Van, Turkey 16Department of Clinical Microbiology, School of Medicine, Gulhane Military Medical School, Ankara, Turkey 17Department of Clinical Microbiology, School of Medicine, Abant Izzet Baysal University, Bolu, Turkey 18Department of Clinical Microbiology, School of Medicine, Erzincan University, Erzincan, Turkey 19Department of Infection Diseases, School of Medicine, Sakarya University, Sakarya, Turkey *Corresponding author : Mustafa Altindis, Department of Clinical Microbiology, Faculty of Medicine, Sakarya University, Sakarya, Turkey. Tel: +90-2642957277, Fax: +90-2642956629, E-mail: [email protected] Received ; Revised ; Accepted 2015 May 13 2015 September 3 2015 September 22. Abstract Background: The prognostic value of blood culture testing in the diagnosis of bacteremia is limited by contamination. Objectives: In this multicenter study, the aim was to evaluate the contamination rates of blood cultures as well as the parameters that affect the culture results. Materials and Methods: Sample collection practices and culture data obtained from 16 university/research hospitals were retrospectively evaluated. A total of 214,340 blood samples from 43,254 patients admitted to the centers in 2013 were included in this study. The blood culture results were evaluated based on the three phases of laboratory testing: the pre-analytic, the analytic, and the post-analytic phase. Results: Blood samples were obtained from the patients through either the peripheral venous route (64%) or an intravascular catheter (36%). Povidone-iodine (60%) or alcohol (40%) was applied to disinfect the skin. Of the 16 centers, 62.5% have no dedicated phlebotomy team, 68.7% employed a blood culture system, 86.7% conducted additional studies with pediatric bottles, and 43.7% with anaerobic bottles. One center maintained a blood culture quality control study. The average growth rate in the bottles of blood cultures during the defined period (1259 - 26,400/year) was 32.3%. Of the growing microorganisms, 67% were causative agents, while 33% were contaminants. The contamination rates of the centers ranged from 1% to 17%. The average growth time for the causative bacteria was 21.4 hours, while it was Escherichia coli 36.3 hours for the contaminant bacteria. The most commonly isolated pathogens were (22.45%) and coagulase-negative staphylococci (CoNS) (20.11%). Further, the most frequently identified contaminant bacteria were CoNS (44.04%). Conclusions: The high contamination rates were remarkable in this study. We suggest that the hospitals’ staff should be better trained in blood sample collection and processing. Sterile glove usage, alcohol usage for disinfection, the presence of a phlebotomy team, and quality control studies may all contribute to decreasing the contamination rates. Health policy makers should therefore provide the necessary financial support to obtain the required materials and equipment. Keywords: Blood Specimen Collection, Phlebotomy, Blood-Borne Pathogens, Bacteriological Techniques Copyright © 2016, Ahvaz Jundishapur University of Medical Sciences. This is an open-access article distributed under the terms of the Creative Commons Attribu- tion-NonCommercial 4.0 International License (http://creativecommons.org/licenses/by-nc/4.0/) which permits copy and redistribute the material just in noncom- mercial usages, provided the original work is properly cited. Altindis M et al. 1. Background Bacteremia is a common cause of morbidity and mortality ulty, Ordu; Duzce University Medical Faculty, Duzce; Yuzun- in hospitalized patients (1). The early and accurate identifica- cuyil University Medical Faculty, Van,; GATA Medical Faculty, tion of the causative organism is therefore necessary for pa- Ankara; Abant Izzet Baysal University Medical Faculty, Bolu; tient survival. The blood culture test is considered to be the and Erzincan University Medical Faculty, Erzincan. All neces- “gold standard” in the diagnosis and treatment of bactere- sary forms, including the daily practices of the centers, were mia. However, the prognostic value of blood culture testing completed by each individual center and then collected at is limited by contamination (2, 3). A blood culture contami- Sakarya University Training and Research Hospital, Sakarya nant is defined as a microorganism isolated from a blood (Figure 1). culture that was introduced into the culture during either The blood culture bottles were incubated in BactecTM BD specimen collection or processing and that was not patho- 9120 and 9240 (Becton Dickinson, MD, USA), BacT/ALERT genic for the patient from whom the blood was collected (2). (bioMerieux, Durham, NC, USA), and VERSATEK blood cul- The most common contaminant microorganisms are ture (TREK Diagnostic Systems, Cleveland, Ohio) systems at coagulase-negative staphylococci and other skin flora spe- 37°C for 7 - 10 days. After growth, the culture samples were Viridans streptococci Corynebacterium cies such as , species inoculated onto 5% sheep blood agar (Oxoid Ltd., Basing- C. jekieum Bacillus Propionibacte- other than , species, and stoke, UK) and the plate was incubated at 36.8°C for 18 - 24 rium acnes (4). The Standards of the American Society for hours. Isolate identification was performed using the BD Microbiology and the Clinical and Laboratory Standards PhoenixTM 100 (Becton Dickinson, MD, USA) and VITEK 2 Institute (CLSI) state that acceptable contamination rates (bioMérieux, Marcy l’Etoile, France) fully automated mi- should be no higher than 2 to 3% (5, 6). Patients with con- crobiology systems and conventional methods. The blood taminated blood cultures often receive unnecessary an- culture results were evaluated based on the three phases tibiotics, and additional laboratory tests are needed to of laboratory testing: the pre-analytic, the analytic, and the determine the cause of the positive blood culture test. Con- post-analytic phase. The evaluated parameters included taminated blood cultures also lead to an increased length patient variables, specimen variables, collection, handling, of hospital stay, increased costs, increased work load, and and processing in the pre-analytic phase; the performance the unnecessary removal of central intravenous lines (7, 8). of selected laboratory tests in the analytic phase; and test High quality blood culture results are dependent on reporting variables, recording, reporting, and interpreting evaluation during the three phases of laboratory testing: in the post-analytic phase (9). the pre-analytic, the analytic, and the post-analytic phase. 4. Results Recently, the use of sensitive automated blood culture systems with rich culture media has led to increased con- tamination rates (2, 9, 10). 4.1. Pre-Analytic Phase Evaluation 2. Objectives The blood samples from the patients were obtained through either the peripheral venous route (64%) or an intravascular In this multicenter study, we aimed to evaluate the catheter (36%). Povidone-iodine (60%) or alcohol (40%) was contamination rates of blood cultures, as well as the pri- applied to disinfect the skin prior to blood sampling (Table 1). mary parameters affecting the culture results, through- Across all the centers, our analysis reveals that 62.5% out the entire process from the collection of the blood of them do not have a dedicated phlebotomy team; in culture to the interpretation of the results in different 93.7% of them blood is drawn while wearing gloves; 73.3% tertiary