Kocoglu M. Esra
(Department of Microbiology and Clinical Microbiology, Faculty of Medicine, Gaziantep University)
,
Bayram Aysen
(Department of Microbiology and Clinical Microbiology, Faculty of Medicine, Gaziantep University)
,
Balcl Iclal
(Department of Microbiology and Clinical Microbiology, Faculty of Medicine, Gaziantep University)
Although automated continuous-monitoring blood culture systems are both rapid and sensitive, false-positive and false-negative results still occur. The objective of this study, then, was to evaluate negative results occurring with BacT/Alert 3D blood culture systems. A total of 1032 samples were cul...
Although automated continuous-monitoring blood culture systems are both rapid and sensitive, false-positive and false-negative results still occur. The objective of this study, then, was to evaluate negative results occurring with BacT/Alert 3D blood culture systems. A total of 1032 samples were cultured with the BacT/Alert 3D automated blood culture system, using both aerobic (BPA) and anaerobic (BPN) media, and 128 of these samples yielded positive results. A total of 904 negative blood samples were then subcultured in $5\%$ sheep blood agar, eosin methylene blue, chocolate agar, and sabouraud-dextrose agar. Organisms growing on these subcultures were subsequently identified using both Vitek32 (bioMerieux, Durham, NC) and conventional methods. Twenty four $(2.6\%)$ of the 904 subcultures grew on the subculture media. The majority $(83.3\%)$ of these were determined to be gram-positive microorganisms. Fourteen $(58.3\%)$ were coagulase-negative staphylococci, two $(8.3\%)$ were Bacillus spp., one $(4.2\%)$ was Staphylococcus aureus, and one $(4.2\%)$ was identified as Enterococcus faecium. Streptococcus pneumoniae and Neisseria spp. were isolated together in two $(8.3\%)$ vials. Gram-negative microorganisms comprised $12.5\%$ of the subcultures, of which two $(8.3\%)$ were found to be Pseudomonas aeruginosa, and one $(4.2\%)$ was Pseudomonas fluorescens. The other isolate $(4.2\%)$ was identified as Candida albicans. We conclude that the subculture of negative results is valuable in the BacT/Alert 3D system, especially in situations in which only one set of blood cultures is taken.
Although automated continuous-monitoring blood culture systems are both rapid and sensitive, false-positive and false-negative results still occur. The objective of this study, then, was to evaluate negative results occurring with BacT/Alert 3D blood culture systems. A total of 1032 samples were cultured with the BacT/Alert 3D automated blood culture system, using both aerobic (BPA) and anaerobic (BPN) media, and 128 of these samples yielded positive results. A total of 904 negative blood samples were then subcultured in $5\%$ sheep blood agar, eosin methylene blue, chocolate agar, and sabouraud-dextrose agar. Organisms growing on these subcultures were subsequently identified using both Vitek32 (bioMerieux, Durham, NC) and conventional methods. Twenty four $(2.6\%)$ of the 904 subcultures grew on the subculture media. The majority $(83.3\%)$ of these were determined to be gram-positive microorganisms. Fourteen $(58.3\%)$ were coagulase-negative staphylococci, two $(8.3\%)$ were Bacillus spp., one $(4.2\%)$ was Staphylococcus aureus, and one $(4.2\%)$ was identified as Enterococcus faecium. Streptococcus pneumoniae and Neisseria spp. were isolated together in two $(8.3\%)$ vials. Gram-negative microorganisms comprised $12.5\%$ of the subcultures, of which two $(8.3\%)$ were found to be Pseudomonas aeruginosa, and one $(4.2\%)$ was Pseudomonas fluorescens. The other isolate $(4.2\%)$ was identified as Candida albicans. We conclude that the subculture of negative results is valuable in the BacT/Alert 3D system, especially in situations in which only one set of blood cultures is taken.
* AI 자동 식별 결과로 적합하지 않은 문장이 있을 수 있으니, 이용에 유의하시기 바랍니다.
문제 정의
Thus, it appears that a blind subculture protocol is, in fact, a necessity. To the best of our knowledge, this study is the first to evaluate false negative results in the BacT/Alert3D system. The 2.
제안 방법
, 1980). As false negative results can clearly affect the course of antibiotic therapy selected and the eventual disease outcome, our objective in organizing this study was to evaluate the occurrence of negative blood culture results on the BacT/ Alert 3D automated blood culture system, and to accurately determine the rate of false negative results, by cul-taring these negative results using traditional classical methods.
pneumoniae isolates were considered to be true pathogens. In order to evaluate the clinical relevance of the false-negative results yielded in this study, it was crucial to count the results of the other sets for the patients who exhibited false-negative results. Unfortunately, as only one set of blood cultures had been acquired from each of the study patients, we were unable to determine the significance of skin flora isolated only from terminal subcultures, and were also unable to determine whether other sets from the same patient would have generated a positive signal, or would have revealed the absence of potential pathogens.
성능/효과
This study demonstrated that 2.6% of results generated by the BacT/Alert 3D system are false-negatives. Culture and antimicrobial susceptibility tests of pathogens are crucial for the effective antimicrobial treatment of bacteremia.
후속연구
Therefore, we conclude that the subculturing of negative results would prove valuable when using the BacT/Alert 3D system, especially in situations in which only one set of blood cultures has been obtained. Further studies with a larger sample will be necessary in order to accurately evaluate the efficacy of the subculturing of negative results in the BacT/Alert 3D system.
참고문헌 (16)
Alfa, M., S. Sanche, S. Roman, Y. Fiola, P. Lenton, and G. Harding. 1995. Continuous quality improvement for introduction of automated blood culture instrument. J. Clin. Microbiol. 33, 1185-1191
Araj, G.F., R.L. Hopfer, M. Wenglar, and V. Fainstein. 1981. Valuable of terminal subcultures from negative BACTEC blood culture bottles. J. Clin. Microbiol. 14, 589-590
Campbell, J. and J.A. Washington, 2nd. 1980. Evaluation of the necessity for routine terminal subcultures of previously negative blood cultures. J. Clin. Microbiol. 12. 576-578
Daxboeck, F., H.J. Dornbusch, R. Krause, O. Assadian, and C. Wenisch. 2004. Verification of false-positive blood culture results generated by the BACTEC 9000 series by eubacterial 16S rDNA and panfungal 18S rDNA directed polymerase chain reaction (PCR). Diagn. Microbiol. Infect. Dis. 48, 1-3
Fontanals, D., I. Sanfeliu, I. Pons, D. Mariscal, and M. Torra. 1998. Evaluation of the BacT/Alert and VITAL blood culture systems for the diagnosis of bacteremia. Clin. Microbiol. Infect. 4, 88-93
Gimenez, M., C. Prat, X. Valles, L. Matas, J. Arnal, and V. Ausina. 2002. Evaluation of the VITAL (bioMerieux) automated blood culture system using blind subculture. Clin. Microbiol. Infect. 8, 222-228
Hardy, D.J., B.B. Hulbert, and P.C. Migneault. 1992. Time to detection of positive BacT/Alert blood cultures and lack of need for routine subculture of 5- to 7-day negative cultures. J. Clin. Microbiol. 30, 2743-2745
Horvath, L.L., B.J. George, C.K., Murray, L.S. Harrison, and D.R. Hospenthal. 2004. Direct comparison of the BACTEC 9240 and BacT/Alert3D automated blood culture systems for candida growth detection. J. Clin. Microbiol. 42, 115-118
Mirrett, S., L.B. Reller, C.A. Petti, C.W. Woods, B. Vazirani, R. Sivadas, and M.P. Weinstein. 2003. Controlled clinical comparison of BacT/Alert standard aerobic medium with BACTEC standard aerobic medium for culturing blood. J. Clin. Microbiol. 41, 2391-2394
Qian, Q., Y.W. Tang, C.P. Kolbert, C.A. Torgerson, J.G. Hughes, E.A. Vetter, W.S. Harmsen, S.O. Montgomery, F.R. Cockerill, 3rd. and D.H. Persing. 2001. Direct identification of bacteria from positive blood cultures by amplification and sequencing of the 16S rRNA gene: evaluation of BACTEC 9240 instrument true-positive and false-positive results. J. Clin. Microbiol. 39, 3578-3582
Schwabe, L.D., R.B. Jr. Thomson, K.K. Flint, and F.P. Koontz. 1995. Evaluation of BACTEC 9240 blood culture system by using high-volume aerobic resin media. J. Clin. Microbiol. 33, 2451-2453
Seegmuller, I., U. Eschenbach, K. Kamereck, and T. Miethke. 2004. Sensitivity of the BacT/Alert FA-medium for detection of Pseudomonas aeruginosa in pre-incubated blood cultures and its temperature-dependence. J. Med. Microbiol. 53, 869-874
Shigei, J.T., J.A. Shimabukuro, M.T. Pezzlo, L.M. de la Maza, and E.M. Peterson. 1995. Value of terminal subcultures for blood cultures monitored by BACTEC 9240. J. Clin. Microbiol. 33, 1385-1388
Wellinghausen, N., B. Wirths, A.R. Franz, L. Karolyi, R. Marre, and U. Reischl. 2004. Algorithm for the identification of bacterial pathogens in positive blood cultures by real-time Light- Cycler polymerase chain reaction (PCR) with sequencespecific probes. Diagn. Microbiol. Infect. Dis. 48, 229-241
AI-Helper
※ AI-Helper는 부적절한 답변을 할 수 있습니다.