scholarly journals A Lateral Flow Immunoassay for the Rapid Identification of CTX-M-Producing Enterobacterales from Culture Plates and Positive Blood Cultures

Diagnostics ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 764 ◽  
Author(s):  
Sandrine Bernabeu ◽  
Kayaththiry Caroline Ratnam ◽  
Hervé Boutal ◽  
Camille Gonzalez ◽  
Anaïs Vogel ◽  
...  
Keyword(s):  
Clinical Setting ◽  
Clinical Microbiology ◽  
Rapid Identification ◽  
Blood Cultures ◽  
Lateral Flow ◽  
Lateral Flow Immunoassay ◽  
Gram Negative ◽  
Negative Results ◽  
Esbl Producers ◽  
Group 1

We have developed a lateral flow immunoassay (LFIA), named NG-Test CTX-M MULTI (NG-Test), to detect group 1, 2, 8, 9, 25 CTX-M producers from agar plates and from positive blood cultures in less than 15 min. The NG-Test was validated retrospectively on 113 well-characterized enterobacterial isolates, prospectively on 102 consecutively isolated ESBL-producers from the Bicêtre hospital and on 100 consecutive blood cultures positive with a gram-negative bacilli (GNB). The NG-Test was able to detect all CTX-M producers grown on the different agar plates used in clinical microbiology laboratories. No false positive nor negative results were observed. Among the 102 consecutive ESBL isolates, three hyper mucous isolates showed an incorrect migration leading to invalid results (no control band). Using an adapted protocol, the results could be validated. The NG-Test detected 99/102 ESBLs as being CTX-Ms. Three SHV producers were not detected. Among the 100 positive blood cultures with GNB tested 10/11 ESBL-producers were detected (8 CTX-M-15, 2 CTX-M-27). One SHV-2-producing-E. cloacae was missed. The NG-Test CTX-M MULTI showed 100% sensitivity and specificity with isolates cultured on agar plates and was able to detect 98% of the ESBL-producers identified in our clinical setting either from colonies or from positive blood cultures.

Acquired Antithrombin III (AT III) - Deficiency in Septicaemia

1979 ◽  
Author(s):  
E. Deutsch ◽  
E. Thaler
Keyword(s):  
Septic Shock ◽  
Venous Blood ◽  
Heparin Therapy ◽  
Blood Cultures ◽  
Mean Values ◽  
Negative Results ◽  
Significant Difference ◽  
At Iii ◽  
Group 2 ◽  
Group 1

AT III was measured in 34 patients with clinical and bacteriological evidence of septicaemia using a heparin cofactor assay. Based on the results of positive blood cultures gram-negative septicaemia (G-S) was diagnosed in 10 (group 1) and gram positive septicaemia (G+S) in 9 patients (group 2). From the remaining 15 patients {group 3) blood cultures before onset of antibiotic therapy were not obtained and gave negative results throughout the observation period. Based on bacteria] cultures from other sites than venous blood or bacteriological examination of spinal fluid G-S was assumed in 13 and G+S in 2 patients.In all but one patient of group 1 and one of group 2 AT III activities were decreased below 2 SO of normal controls (n = 91, x = 99.6, SD-8.4) already at the time of the first coagulation screening (patients: n=34, =58.4, SD-16.6). Analysis of var-ance showed no significant difference between the mean values of the three groups at the c per cent (%) level. The minimal AT III activities during the course of the disease were below the norma] range in all patients studied [n=34, =51.2, SD=13.6).Thus AT III deficiency appears to be a constant and early finding in G-S and G+S, causing insufficient inhibition of blood coagulation, and hereby may contribute to irreversible tissue damage caused by microthrombi in septic shock. This deficiency may be an important factor in the failure of heparin therapy to reduce mortality from septic shock.

scholarly journals Evaluation of Verigene Blood Culture Test Systems for Rapid Identification of Positive Blood Cultures

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Jae-Seok Kim ◽  
Go-Eun Kang ◽  
Han-Sung Kim ◽  
Hyun Soo Kim ◽  
Wonkeun Song ◽  
...  
Keyword(s):  
Blood Culture ◽  
Resistance Genes ◽  
Rapid Identification ◽  
Blood Cultures ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Single Strain ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Susceptibility Tests

The performance of molecular tests using the Verigene Gram-Positive and Gram-Negative Blood Culture nucleic acid tests (BC-GP and BC-GN, resp.; Naosphere, Northbrook, IL, USA) was evaluated for the identification of microorganisms detected from blood cultures. Ninety-nine blood cultures containing Gram-positive bacteria and 150 containing Gram-negative bacteria were analyzed using the BC-GP and BC-GN assays, respectively. Blood cultures were performed using the Bactec blood culture system (BD Diagnostic Systems, Franklin Lakes, NJ, USA) and conventional identification and antibiotic-susceptibility tests were performed using a MicroScan system (Siemens, West Sacramento, CA, USA). When a single strain of bacteria was isolated from the blood culture, Verigene assays correctly identified 97.9% (94/96) of Gram-positive bacteria and 93.8% (137/146) of Gram-negative bacteria. Resistance genesmecAandvanAwere correctly detected by the BC-GP assay, while the extended-spectrumβ-lactamase CTX-M and the carbapenemase OXA resistance gene were detected from 30 cases cultures by the BC-GN assay. The BC-GP and BC-GN assays showed high agreement with conventional identification and susceptibility tests. These tests are useful for rapid identification of microorganisms and the detection of clinically important resistance genes from positive Bactec blood cultures.

scholarly journals Rapid Detection of VanA/B-Producing Vancomycin-Resistant Enterococci Using Lateral Flow Immunoassay

Diagnostics ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1805
Author(s):  
Saoussen Oueslati ◽  
Camille Gonzalez ◽  
Hervé Volland ◽  
Vincent Cattoir ◽  
Sandrine Bernabeu ◽  
...  
Keyword(s):  
Sensitivity And Specificity ◽  
Rapid Detection ◽  
Clinical Microbiology ◽  
Lateral Flow ◽  
Lateral Flow Immunoassay ◽  
Bacterial Cells ◽  
Efficient Management ◽  
Vancomycin Resistant Enterococci ◽  
Vancomycin Resistant ◽  
Prolonged Hospital

Vancomycin-resistant enterococci (VREs) have become one of the most important nosocomial pathogens worldwide, associated with increased treatment costs, prolonged hospital stays and high mortality. Rapid detection is crucial to reduce their spread and prevent infections and outbreaks. The lateral flow immunoassay NG-Test VanB (NG Biotech) was evaluated for the rapid detection of VanB-producing vancomycin-resistant enterococci (VanB-VREs) using 104 well-characterized enterococcal isolates. The sensitivity and specificity were both 100% when bacterial cells were grown in the presence of vancomycin used as a VanB inducer. The NG-Test VanB is an efficient, rapid and easy to implement assay in clinical microbiology laboratories for the confirmation of VanB-VREs from colonies. Together with the NG-Test VanA, they could replace the already existing tests available for the confirmation of acquired vancomycin resistance in enterococci, especially from selective media or from antibiograms, with 100% sensitivity and specificity. Rapid detection in less than 15 min will result in more efficient management of carriers and infected patients. In addition, these tests may be used for positive blood cultures, given a 3.5 h sub-culturing step on Chocolate agar PolyViteX in the presence of a 5-µg vancomycin disk, which is routinely performed in many clinical microbiology laboratories for every positive blood culture for subsequent MALDI-TOF identification of the growing bacteria.

What are the critical steps in processing blood cultures? A prospective audit evaluating current practice of reporting blood cultures in a centralised laboratory serving secondary care hospitals

2016 ◽  
Vol 70 (4) ◽  
pp. 361-366 ◽  
Author(s):  
Manjula Meda ◽  
James Clayton ◽  
Reela Varghese ◽  
Jayakeerthi Rangaiah ◽  
Clive Grundy ◽  
...  
Keyword(s):  
Blood Culture ◽  
Secondary Care ◽  
Rapid Identification ◽  
Antimicrobial Treatment ◽  
Blood Cultures ◽  
National Standards ◽  
Gram Stain ◽  
Gram Positive ◽  
Gram Negative ◽  
Common Intervention

AimsTo assess current procedures of processing positive blood cultures against national standards with an aim to evaluate its clinical impact and to determine the utility of currently available rapid identification and susceptibility tests in processing of blood cultures.MethodsBlood cultures from three secondary care hospitals, processed at a centralised laboratory, were prospectively audited. Data regarding processing times, communication with prescribers, changes to patient management and mortality within 30 days of a significant blood culture were collected in a preplanned pro forma for a 4-week period.ResultsOf 2206 blood cultures, 211 positive blood cultures flagged positive. Sixty-nine (3.1%) of all cultures were considered to be contaminated. Fifty per cent of blood cultures that flagged positive had a Gram stain reported within 2 hours. Two (0.99%) patients with a significant bacteraemia had escalation of antimicrobial treatment at the point of reporting the Gram stain that was subsequently deemed necessary once sensitivity results were known. Most common intervention was de-escalation of therapy for Gram-positive organisms at the point of availability of pathogen identification (25.6% in Gram positive vs 10% in Gram negative; p=0.012). For Gram-negative organisms, the most common intervention was de-escalation of therapy at the point of availability of sensitivity results (43% in Gram negatives vs 17.9% in Gram positive; p=0.0097). Overall mortality within 30 days of a positive blood culture was 10.9% (23/211). Antibiotic resistance may have contributed to mortality in four of these patients (three Gram negative and one Gram positive).ConclusionGram stain result had the least impact on antibiotic treatment interventions (escalation or de-escalation). Tests that improve identification time for Gram-positive pathogens and sensitivity time for Gram-negative pathogens had the greatest impact in making significant changes to antimicrobial treatment.

scholarly journals A Prospective Evaluation of Two Rapid Phenotypical Antimicrobial Susceptibility Technologies for the Diagnostic Stewardship of Sepsis

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Cesira Giordano ◽  
Elena Piccoli ◽  
Veronica Brucculeri ◽  
Simona Barnini
Keyword(s):  
Antimicrobial Susceptibility ◽  
Multidrug Resistant ◽  
Rapid Identification ◽  
Blood Cultures ◽  
Gram Positive ◽  
Gram Negative ◽  
Maldi Tof Ms ◽  
Gram Positive Bacteria ◽  
Maldi Tof ◽  
Tof Ms

Rapid identification of bloodstream pathogens by MALDI-TOF MS and the recently introduced rapid antimicrobial susceptibility testing (rAST) directly from positive blood cultures allow clinicians to promptly achieve a targeted therapy, especially for multidrug resistant microorganisms. In the present study, we propose a comparison between phenotypical rASTs performed in light-scattering technology (Alfred 60AST, Alifax®) and fluorescencein situhybridization (Pheno™, Accelerate) directly from positive blood cultures, providing results in 4–7 hours. Blood samples from 67 patients admitted to the Azienda Ospedaliero-Universitaria Pisana were analyzed. After the direct MALDI-TOF MS identification, the rAST was performed at the same time both on Alfred 60AST and Pheno. Alfred 60AST provided qualitative results, interpreted in terms of clinical categories (SIR). Pheno provided identification and MIC values for each antibiotic tested. Results were compared to the broth microdilution assay (SensiTitre™, Thermo Fisher Scientific), according to EUCAST rules. Using Alfred 60AST, an agreement was reached, 91.1% for Gram-negative and 95.7% for Gram-positive bacteria, while using Pheno, the agreement was 90.6% for Gram-negative and 100% for Gram-positive bacteria. Both methods provided reliable results; Alfred 60AST combined with MALDI-TOF MS proved itself faster and cheaper. Pheno provided identification and MIC determination in a single test and, although more expensive, may be useful whenever MIC value is necessary and where MALDI-TOF MS is not present.

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