ABSTRACT
Purpose: Differentiation of Staphylococcus aureus (S. aureus) from coagulase-negative staphylococci is very important in blood stream infections. Identification of S. aureus and coagulase-negative staphylococci (CoNS) from blood cultures takes generally 18-24 h after positive signaling on continuously monitored automated blood culture system. In this study, we evaluated the performance of tube coagulase test (TCT), slide agglutination test (Dry Spot Staphytect Plus), conventional polymerase chain reaction (PCR) and LightCycler Staphylococcus MGrade kit directly from blood culture bottles to achieve rapid identification of S. aureus by using the BACTEC 9240 blood culture system. Materials and Methods: A total of 129 BACTEC 9240 bottles growing gram-positive cocci suggesting Staphylococci were tested directly from blood culture broths (BCBs) with TCT, Dry Spot Staphytect Plus, conventional PCR and LightCycler Staphylococcus MGrade kit for rapid identification of S. aureus. Results: The sensitivities of the tests were 99, 68, 99 and 100%, respectively. Conclusion: Our results suggested that 2 h TCT was found to be simple and inexpensive method for the rapid identification of S. aureus directly from positive blood cultures.
Subject(s)
Bacteremia/diagnosis , Bacteremia/microbiology , Bacteriological Techniques/methods , Blood/microbiology , Coagulase/analysis , Coagulase/genetics , Humans , Sensitivity and Specificity , Staphylococcal Infections/diagnosis , Staphylococcal Infections/microbiology , Staphylococcus aureus/isolation & purification , Time FactorsABSTRACT
BACKGROUND: We investigated whether culture using an automated blood culture system enhances the recovery of bacteria and fungi from body fluids other than blood when compared to conventional solid media culture methods. METHODS: A total of 734 specimens [ascites (n=457), bile (n=5), CAPD (n=28), CSF (n=32), joint fluids (n=165), pericardial fluid (n=17), and pleural fluid (n=30)] were included in the study. Half of the volume of each specimen was inoculated directly into automated blood culture bottles (bioMeriux, Marcy-I'Etoile, France). The remaining volume was inoculated onto conventional solid media (sheep blood agar, chocolate agar, and phenylethyl alcohol agar) after centrifuging at 3,000 rpm for 10 min. RESULTS: Clinically significant microorganisms were isolated from 62 specimens (8.5%) by automated blood culture and 61 specimens (8.3%) by the conventional solid media culture (kappa index: 0.81, 95% confidence interval: 0.75~0.89). Contamination was observed in 11 (1.8%) of the automated blood culture specimens and 3 (0.4%) of the solid media culture specimens. The mean turnaround times of the automated blood cultures and the conventional solid media cultures were 3.7 and 2.8 days, respectively (P<0.0001). CONCLUSION: Compared with conventional culture methods, no improvement in the recovery of clinically significant microorganisms was noted with the use of the automated blood culture system for the culture of body fluids other than blood.
Subject(s)
Agar , Bacteria , Bile , Body Fluids , Cacao , Fungi , Joints , Peritoneal Dialysis, Continuous Ambulatory , Phenylethyl AlcoholABSTRACT
OBJECTIVE To evaluate the clinical application of BacT/Alert 3D automatic blood culture system.METHODS Totally 3610 blood specimens were cultured by BacT/Alert 3D automatic blood culture system.RESULTS Four hundred and three of 3610 blood specimens were positive,and the positive rate was 11.2%.The cumulative positive rates within 24 h,24-48 h,48-72 h,and longer than 72 h were 64.3%,21.1%,11.4% and 3.2%,respectively.CONCLUSIONS BacT/Alert 3D automatic blood culture system is an accurate,quick and convenient method for bacteria culture,which can detect wide range of bacteria strains,elevate detection ratc,and shorten detection period.
ABSTRACT
BACKGROUND: This study was designed to evaluate the performance of FAN-aerobic bottles (FANA) in comparison with standard-aerobic bottles (STD-A) in BacT/Alert3D blood culture system. METHODS: A total of 596 pairs of blood cultures, submitted from Emergency Department of Pusan National University Hospital between July and December 2004, were evaluated. In addition to the routine blood culture protocol using standard blood culture bottles, 5 ml of blood samples was inoculated into FAN-A bottles for this study. RESULTS: Microorganisms were grown in 84 (14.1%) of 596 cultures; of those, 15 were positive in STD-A only (2.5%), 35 in FAN-A only (5.9%), and 34 in both (5.7%). The positive rate in FAN-A bottles was significantly higher than that in STD-A bottles (P<0.001). The species of isolates and detection time showed no difference between the blood culture bottles. CONCLUSION: In the BacT/Alert3D blood culture system, the use of FAN-A bottles instead of the standard aerobic bottles should yield a higher positive rate.
Subject(s)
Emergency Service, HospitalABSTRACT
BACKGROUND: Inoculation of ascitic fluid into blood culture bottles is known to be more efficient than conventional culture method to diagnose spontaneous bacterial peritonitis. The aim of this study is to evaluate recovery and early detection of peritonitis-causing bacteria from ascitic fluid by using the BACTEC blood culture system with bedside inoculation. The results were compared to those of conventional culture method. METHODS: Ascitic fluid specimens from 345 patients suspicious of spontaneous bacterial peritonitis were prospectively evaluated between January 1999 and March 2002. In all cases, 5 to 10 mL of ascitic fluid were inoculated at the bedside into a pair of BACTEC blood culture bottles (BC method), and simultaneously an aliquot of ascitic fluid was sent to microbiology laboratory for conventional culture. Isolated microorganisms and the time elapsed for final report were compared between the two methods. RESULTS: BC method was positive in 66/345 ascitic fluid specimens (19.1%) and conventional culture method in 48/345 (13.9%) (P=0.065). Time elapsed for final report was 82 20.5 hours for blood culture method and 107 42.4 hours for conventional culture method (P=0.002). CONCLUSION: BC method using BACTEC system provides an earlier microbiologic diagnosis of spontaneous bacterial peritonitis than conventional culture method with higher sensitivity.
Subject(s)
Humans , Ascitic Fluid , Bacteria , Diagnosis , Peritonitis , Prospective StudiesABSTRACT
BACKGROUND: Many invasive and life-threatening infections are diagnosed by the culture of normally sterile body fluids. Because microorganisms are present in very low concentrations, and these infections are often caused by fastidious or slow-growing microorganisms, they may not be detected by conventional culture methods. The present study was designed to assess the performance of the BacT/Alert blood culture system in order to recover microorganism with standard aerobic and anaerobic bottles and FAN aerobic and anaerobic bottles versus conventional culture methods for culturing normally sterile body fluids other than blood. METHODS: Between February and April 2003, sterile body fluids, such as cerebrospinal fluids (CSF), pleural fluids, peritoneal fluids, continuous ambulatory peritoneal dialysate (CAPD), and other fluids submitted to the microbiology laboratory for culture were entered into the study. Only specimens with a minimum volume of 3.0 mL were included, and the specimens were divided equally among three arms of the study. All BacT/Alert bottles were monitored for up to 5 days. Conventional blood agar plate and thioglycollate broth were incubated for up to 3 days before being discarded as negative, while anaerobic cultures were maintained for a minimum of 5 days. Bacterial identification and antimicrobial susceptibility tests were performed using standard laboratory protocols. RESULTS: A total of 247 specimens (CSF 85, pleural fluids 68, peritoneal fluids 71, CAPD 17, others 6) were included in this study, with 45 isolates recovered from 43 specimens. The recovery rates for each method were standard bottles 65.1% (28/43), FAN bottles 79.1% (34/43), and conventional culture 48.9% (21/43). For CSF and peritoneal fluids, more isolates were recovered from the FAN bottles compared to the conventional culture or standard bottles. The FAN bottles recovered more coagulase negative staphylococci than those from the conventional culture or standard bottles. CONCLUSIONS: Even though the BacT/Alert system using FAN bottles improved the recovery rate for CSF and peritoneal fluids compared to either the standard bottles or conventional culture, coagulase negative staphylococci were also frequently recovered. Therefore, further evaluations are required to assess the clinical usefulness of culturing sterile body fluids using the Bact/Alert blood culture system.