Early detection with the β-LACTA™ test of extended-spectrum β-lactamase–producing Enterobacteriaceae in blood cultures

Walewski, Violaine; Podglajen, Isabelle; Lefeuvre, Pierre; Dutasta, F.; Neuschwander, Arthur; Tilouche, L.; Carbonnelle, Étienne; Ferroni, Agnès

doi:10.1016/j.diagmicrobio.2015.07.005

Cited by 12 publications

(12 citation statements)

References 11 publications

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“…Although several studies have previously reported the very good intrinsic diagnostic performance of the BLT [14–17, 27], we reported its added clinical value for the first time, even when empirical beta-lactam antibiotic was chosen according to guidelines. The cost of the procedure also appears as strength since the device is inexpensive (3.5 €) and takes little time to perform (2 minutes for the assay and 15 minutes for the incubation prior to analyze the result).…”

Section: Discussionmentioning

confidence: 87%

“…To our knowledge, no test meeting these requirements has yet been validated for GNB in a clinical setting. Taking into account the very good diagnostic performance of the BLT [14–17, 27], we performed this pilot study and demonstrated that the BLT is a promising approach to reach this dual objective. Indeed, the BLT-guided adaptation of antimicrobial therapy independently increased its appropriateness and optimality to 98% and 95%, respectively, within a median of 30 hours before the availability of antibiotic susceptibility test results.…”

Section: Discussionmentioning

confidence: 99%

“…Indeed, several protocols enable the efficient detection of Enterobacteriaceae that produce ESBL directly from the microbiological samples [17, 27, 31]. As such, it could be hypothesized that the direct use of the BLT on a microbiological sample that is positive for GNB on direct examination could shorten the duration of inappropriate EAT to a couple of hours.…”

Section: Discussionmentioning

confidence: 99%

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Evaluation of early antimicrobial therapy adaptation guided by the BetaLACTA® test: a case-control study

et al. 2017

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BackgroundRapid diagnostic tests detecting microbial resistance are needed for limiting the duration of inappropriateness of empirical antimicrobial therapy (EAT) in intensive care unit patients, besides reducing the use of broad-spectrum antibiotics. We hypothesized that the betaLACTA® test (BLT) could lead to early increase in the adequacy of antimicrobial therapy.MethodsThis was a case-control study. Sixty-one patients with BLT-guided adaptation of EAT were prospectively included, and then matched with 61 “controls” having similar infection characteristics (community or hospital-acquired, and source of infection), in whom EAT was conventionally adapted to antibiogram results. Endpoints were to compare the proportion of appropriate (primary endpoint) and optimal (secondary endpoint) antimicrobial therapies with each of the two strategies, once microbiological sample culture results were available.ResultsCharacteristics of patients, infections and EAT at inclusion were similar between groups. Nine early escalations of EAT occurred in the BLT-guided adaptation group, reaching 98% appropriateness vs. 77% in the conventional adaptation group (p < 0.01). The BLT reduced the time until escalation of an inappropriate EAT from 50.5 (48–73) to 27 (24–28) hours (p < 0.01). Seventeen early de-escalations occurred in the BLT-guided adaptation group, compared to one in the conventional adaptation group, reducing patients’ exposure to broad-spectrum beta-lactam such as carbapenems. In multivariate analysis, use of the BLT was strongly associated with early appropriate (OR = 18 (3.4–333.8), p = 0.006) and optimal (OR = 35.5 (9.6–231.9), p < 0.001) antimicrobial therapies. Safety parameters were similar between groups.ConclusionsOur study suggests that a BLT-guided adaptation strategy may allow early beta-lactam adaptation from the first 24 hours following the beginning of sepsis management.Electronic supplementary materialThe online version of this article (doi:10.1186/s13054-017-1746-6) contains supplementary material, which is available to authorized users.

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Section: Discussionmentioning

confidence: 87%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

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Evaluation of early antimicrobial therapy adaptation guided by the BetaLACTA® test: a case-control study

et al. 2017

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“…Colorimetric tests have recently been developed to detect enzymatic degradationdmainly of b-lactamsdusing a chromogenic substrate or a pH indicator for colour change in the medium. Initially designed to be performed on colonies, several of these tests have been evaluated directly on positive BC pellets with results returned within 1 h. Performances of assays of 3GC resistance in Enterobacteriaceae can vary [56,57], as some are unable to detect AmpC overexpressing isolates (Table 3). Similar tests exist for detecting carbapenemase-producing Enterobacteriaceae, or colistin-resistant Enterobacteriaceae.…”

Section: Rapid Testsmentioning

confidence: 99%

Rapid phenotypic methods to improve the diagnosis of bacterial bloodstream infections: meeting the challenge to reduce the time to result

Dubourg

Lamy

Ruimy

2018

Clinical Microbiology and Infection

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“…Two previous evaluations of the ␤-Lacta test from positive blood cultures have been reported (10,11). One study, using growth from a 3-hour subculture, found that the ␤-Lacta test detected 28 (84.8%) of 33 blood culture isolates resistant to thirdgeneration cephalosporins (10).…”

mentioning

confidence: 99%

Evaluation of the β-Lacta Test for Detection of Extended-Spectrum-β-Lactamase (ESBL)-Producing Organisms Directly from Positive Blood Cultures by Use of Smudge Plates

2017

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I nvasive infections due to extended-spectrum-␤-lactamase-producing Enterobacteriaceae (ESBL-E) are associated with considerable morbidity and mortality and excess hospital costs (1-4). It is assumed that early identification of ESBL-E bacteremia may lead to optimized treatment, contributing to better outcomes (5). The ␤-Lacta test (Bio-Rad, Marnes-La-Coquette, France) is a chromogenic assay that can detect resistance to third-generation cephalosporins associated with ESBL production in Enterobacteriaceae within 15 min (6). The test has been successfully used for direct detection of ESBL-E in urine samples submitted for culture (7). This study evaluated the accuracy of the ␤-Lacta test for rapid detection of Ambler class A ESBL-E from smudge plates prepared from positive blood cultures. The study was conducted at Sunnybrook Health Sciences Centre, a tertiary-care hospital in Toronto, Canada, from August 2016 to July 2017. Blood cultures were collected in Bactec Plus aerobic and anaerobic bottles incubated in the BD Bactec 9240 automated blood culture system (BD Diagnostic Systems, Sparks, MD). Blood cultures that were flagged as positive with Gram-negative bacilli seen in microscopy were included in the study. A 3-ml aliquot aspirated from the blood culture broth was centrifuged, and the bacterial pellet was used to prepare a smudge plate on chocolate agar, as previously described (8). Smudge plates were incubated at 35°C for 2 h, and the resultant bacterial growth was used for organism identification with matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) using the Vitek-MS system (software v2.0; bioMérieux, Durham, NC) (8). If Escherichia coli or Klebsiella species was identified by the MALDI-TOF MS, the smudge plate growth was used for the ␤-Lacta test, done in accordance with the manufacturer's instructions. Standard laboratory procedures were used to subculture the positive blood cultures and identify the organisms. Antimicrobial susceptibility testing, including determination of susceptibilities to ceftriaxone and ceftazidime, and confirmation of ESBLs were done in accordance with CLSI guidelines (9). Results obtained with the ␤-Lacta test from smudge plates were interpreted prior to and in a manner blind to conventional test results. Specimens yielding polymicrobial growth were excluded from the evaluation. A total of 202 E. coli, 60 Klebsiella pneumoniae, and 7 Klebsiella oxytoca blood culture isolates were included in this evaluation; 39 (19.3%) E. coli and 7 (10.4%) Klebsiella isolates were confirmed as ESBL producing. All 46 ESBL-E isolates were positive by the ␤-Lacta test (sensitivity, 100%; 95% confidence interval [CI], 92.3% to 100%) (Table 1).

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Early detection with the β-LACTA™ test of extended-spectrum β-lactamase–producing Enterobacteriaceae in blood cultures

Cited by 12 publications

References 11 publications

Evaluation of early antimicrobial therapy adaptation guided by the BetaLACTA® test: a case-control study

Evaluation of early antimicrobial therapy adaptation guided by the BetaLACTA® test: a case-control study

Rapid phenotypic methods to improve the diagnosis of bacterial bloodstream infections: meeting the challenge to reduce the time to result

Evaluation of the β-Lacta Test for Detection of Extended-Spectrum-β-Lactamase (ESBL)-Producing Organisms Directly from Positive Blood Cultures by Use of Smudge Plates

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