title: Performance of two resin-containing blood culture media in detection of bloodstream infections and in direct matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) broth assays for isolate identification: clinical comparison of the BacT/Alert Plus and Bactec Plus systems.
abstract: We compared the clinical performances of the BacT/Alert Plus (bioMérieux) and Bactec Plus (Becton Dickinson) aerobic and anaerobic blood culture (BC) media with adsorbent polymeric beads. Patients ≥ 16 years old with suspected bloodstream infections (BSIs) were enrolled in intensive care units and infectious disease wards. A single 40-ml blood sample was collected from each and used to inoculate (10 ml/bottle) one set of BacT/Alert Plus cultures and one set of Bactec Plus cultures, each set consisting of one aerobic and one anaerobic bottle. Cultures were incubated ≤ 5 days in the BacT/Alert 3D and Bactec FX instruments, respectively. A total of 128 unique BSI episodes were identified based on the recovery of clinically significant growth in 212 aerobic cultures (106 BacT/Alert and 106 Bactec) and 151 anaerobic cultures (82 BacT/Alert and 69 Bactec). The BacT/Alert aerobic medium had higher recovery rates for Gram-positive cocci (P = 0.024), whereas the Bactec aerobic medium was superior for recovery of Gram-negative bacilli (P = 0.006). BacT/Alert anaerobic medium recovery rates exceeded those of the Bactec anaerobic medium for total organisms (P = 0.003), Gram-positive cocci (P = 0.013), and Escherichia coli (P = 0.030). In terms of capacity for diagnosing the 128 septic episodes, the BacT/Alert and Bactec sets were comparable, although the former sets diagnosed more BSIs caused by Gram-positive cocci (P = 0.008). They also allowed earlier identification of coagulase-negative staphylococcal growth (mean, 2.8 h; P = 0.003) and growth in samples from patients not on antimicrobial therapy that yielded positive results (mean, 1.3 h; P < 0.001). Similarly high percentages of microorganisms in BacT/Alert and Bactec cultures (93.8% and 93.3%, respectively) were identified by direct matrix-assisted laser desorption ionization-time of flight mass spectrometry assay of BC broths. The BacT/Alert Plus media line appears to be a reliable, timesaving tool for routine detection of BSIs in the population we studied, although further studies are needed to evaluate their performance in other settings.
authors.affiliation: Institute of Microbiology, Catholic University of the Sacred Heart, Gemelli Hospital, Rome, Italy.
authors.forename: Barbara
authors.initials: B
authors.lastname: Fiori
authors.affiliation: Institute of Microbiology, Catholic University of the Sacred Heart, Gemelli Hospital, Rome, Italy.
authors.forename: Tiziana
authors.initials: T
authors.lastname: D'Inzeo
authors.affiliation: Institute of Microbiology, Catholic University of the Sacred Heart, Gemelli Hospital, Rome, Italy.
authors.forename: Viviana
authors.initials: V
authors.lastname: Di Florio
authors.affiliation: Institute of Microbiology, Catholic University of the Sacred Heart, Gemelli Hospital, Rome, Italy.
authors.forename: Flavio
authors.initials: F
authors.lastname: De Maio
authors.affiliation: Institute of Microbiology, Catholic University of the Sacred Heart, Gemelli Hospital, Rome, Italy.
authors.forename: Giulia
authors.initials: G
authors.lastname: De Angelis
authors.affiliation: Institute of Microbiology, Catholic University of the Sacred Heart, Gemelli Hospital, Rome, Italy.
authors.forename: Alessia
authors.initials: A
authors.lastname: Giaquinto
authors.affiliation: Institute of Infectious Diseases, Catholic University of the Sacred Heart, Gemelli Hospital, Rome, Italy.
authors.forename: Lara
authors.initials: L
authors.lastname: Campana
authors.affiliation: Department of Clinical Anesthesiology and Intensive Care, Catholic University of the Sacred Heart, Gemelli Hospital, Rome, Italy.
authors.forename: Eloisa
authors.initials: E
authors.lastname: Tanzarella
authors.affiliation: Institute of Infectious Diseases, Catholic University of the Sacred Heart, Gemelli Hospital, Rome, Italy.
authors.forename: Mario
authors.initials: M
authors.lastname: Tumbarello
authors.affiliation: Department of Clinical Anesthesiology and Intensive Care, Catholic University of the Sacred Heart, Gemelli Hospital, Rome, Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Antonelli
authors.affiliation: Institute of Microbiology, Catholic University of the Sacred Heart, Gemelli Hospital, Rome, Italy msanguinetti@rm.unicatt.it.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Sanguinetti
authors.affiliation: Institute of Microbiology, Catholic University of the Sacred Heart, Gemelli Hospital, Rome, Italy.
authors.forename: Teresa
authors.initials: T
authors.lastname: Spanu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001419:Bacteria / Q000145:classification / Q000302:isolation & purification*; D001769:Blood / Q000382:microbiology*; D003470:Culture Media / Q000737:chemistry*; D005260:Female; D006801:Humans; D008297:Male; D008828:Microbiological Techniques / Q000379:methods*; D008875:Middle Aged; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D018805:Sepsis / Q000175:diagnosis*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D015003:Yeasts / Q000145:classification / Q000302:isolation & purification*; D055815:Young Adult
chemical_list: D003470:Culture Media