Direct identification of Gram-positive bacteria and resistance determinants from blood cultures using a microarray-based nucleic acid assay: in-depth analysis of microarray data for undetermined results

2015 ◽  
Vol 53 (7) ◽  
Author(s):  
Seon Young Kim ◽  
Yun Ji Hong ◽  
Sang Mee Hwang ◽  
Taek Soo Kim ◽  
Jae-Seok Kim ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Blood Culture ◽  
Blood Cultures ◽  
Automated System ◽  
Correct Identification ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Resistance Determinants ◽  
Depth Analysis ◽  
Nucleic Acid Assay

AbstractThe Verigene Gram-Positive Blood Culture (BC-GP) nucleic acid assay (Nanosphere, Inc., Northbrook, IL, USA) is a newly developed microarray-based test with which 12 Gram-positive bacterial genes and three resistance determinants can be detected using blood culture broths. We evaluated the performance of this assay and investigated the signal characteristics of the microarray images.At the evaluation stage, we tested 80 blood cultures that were positive for various bacteria (68 bacteria covered and 12 not covered by the BC-GP panel) collected from the blood of 36 patients and 44 spiked samples. In instances where the automated system failed and errors were called, we manually inspected microarray images, measured the signal intensities of target spots, and reclassified the results.With the manual analysis of the microarray images of 14 samples for which error calls were reported, we could obtain correct identification results for 12 samples without the need for retesting, because strong signals in the target spots were clearly discriminable from background noise. With our interpretation strategy, we could obtain 97.1% sensitivity and 100% specificity for bacterial identification by using the BC-GP assay. The two unidentified bacteria were viridans group streptococci, which produced weaker target signals. During the application stage, among 25 consecutive samples positive for Gram-positive bacteria, we identified two specimens with error calls asWith help of the manual review of the microarray images, the BC-GP assay could successfully identify species and resistance markers for many clinically important Gram-positive bacteria.

scholarly journals Incidence of secondary blood stream infections in Covid 19 (SARS-nCoV II.) patients

2021 ◽  
Vol 8 (2) ◽  
pp. 128-131
Author(s):  
Asmabanu Shaikh ◽  
Rachana Patel ◽  
Anant Marathe
Keyword(s):  
Blood Culture ◽  
Blood Stream ◽  
Blood Cultures ◽  
Automated System ◽  
Empiric Antibiotic Therapy ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Blood Stream Infections ◽  
Gram Negative ◽  
Gram Positive Bacteria

The symptomatology and severity of covid-19 ranges widely depending on stage of infection. Most of the patients with mild to moderate disease can be managed without hospitalization. The patients with risk factors are likely to progress to severe disease. Patients developing secondary blood stream infections require longer hospital stay and are likely to develop fatal disease. The antibiotic selection is key to successful treatment of secondary BSI. This is cross-sectional study of 166 COVID 19 patients admitted to ICU of Parul Sevashram Hospital who developed sepsis like syndrome and were subjected to blood culture.Blood cultures were performed of all the patients developing sepsis like syndrome. IDSA guidelines were followed during blood collection for culture. Blood cultures were monitored on automated blood culture system. ID and susceptibility of all the isolates were performed on automated system (VITEK 2).A total of 1915 patients were reported RT-PCR positive for SARS nCoV2 during the period of 1st March2020 to 30 October 2020. 452 patients needed hospitalization based on their Oxygen saturation and co-morbidities. Out of 452, 166 patients developed sepsis like syndrome and were subjected to blood culture. The Blood culture positivity was 37/166 (22.28%). Gram positive bacteria were found in 48.64% while gram negative bacteria were 43.24%. The Enterococcus was the most common Gram positive bacterial isolates in patients. Candida was isolated in 2/37 positive blood cultures. Gram negative bacteria were isolated mostly amongst those patients who were on Ventilator. Most of the Gram positive bacteria were sensitive to Clindamycin, Linezolid, Vancomycin, Daptomycin and Teicoplanin.The incidence rate of BSI was high. Early secondary blood stream infections were mostly endogenous. Enterococcus was the most common amongst Gram positive bacteria. Gram negative secondary bacterial infections were more common with patients on ventilator. The susceptibility pattern would help in decision making of empiric antibiotic therapy. Interestingly as described by some authors earlier the relationship between SARS nCoV 2 and Enterococci needs to be studied further.

scholarly journals Clinical Evaluation of the iCubate iC-GPC Assay for Detection of Gram-Positive Bacteria and Resistance Markers from Positive Blood Cultures

2018 ◽  
Vol 56 (9) ◽  
Author(s):  
Paul A. Granato ◽  
Melissa M. Unz ◽  
Raymond H. Widen ◽  
Suzane Silbert ◽  
Stephen Young ◽  
...  
Keyword(s):  
Blood Culture ◽  
Staphylococcus Epidermidis ◽  
Bloodstream Infections ◽  
Blood Cultures ◽  
Gram Positive ◽  
Content Type ◽  
Gram Positive Bacteria ◽  
Sequencing Method ◽  
Resistance Markers ◽  
Gram Positive Cocci

ABSTRACT The iC-GPC Assay (iCubate, Huntsville, AL) is a qualitative multiplex test for the detection of five of the most common Gram-positive bacteria (Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae, Enterococcus faecalis, and Enterococcus faecium) responsible for bacterial bloodstream infections, performed directly from positive blood cultures. The assay also detects the presence of the mecA, vanA, and vanB resistance determinants. This study comparatively evaluated the performance of the iC-GPC Assay against the Verigene Gram-positive blood culture (BC-GP) assay (Luminex Corp., Austin, TX) for 1,134 patient blood culture specimens positive for Gram-positive cocci. The iC-GPC Assay had an overall percent agreement with the BC-GP assay of 95.5%. Discordant specimens were further analyzed by PCR and a bidirectional sequencing method. The results indicate that the iC-GPC Assay together with the iCubate system is an accurate and reliable tool for the detection of the five most common Gram-positive bacteria and their resistance markers responsible for bloodstream infections.

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 Preliminary Evaluation of the Research-Use-Only (RUO) iCubate iC-GPC Assay for Identification of Select Gram-Positive Bacteria and Their Resistance Determinants in Blood Culture Broths: TABLE 1

2015 ◽  
Vol 53 (12) ◽  
pp. 3931-3934 ◽  
Author(s):  
Blake W. Buchan ◽  
Garrett C. Reymann ◽  
Paul A. Granato ◽  
Brenda R. Alkins ◽  
Patricia Jim ◽  
...  
Keyword(s):  
Blood Culture ◽  
Staphylococcus Epidermidis ◽  
Bacterial Species ◽  
Genetic Resistance ◽  
Preliminary Evaluation ◽  
Gram Positive ◽  
Content Type ◽  
Gram Positive Bacteria ◽  
Resistance Determinants ◽  
On Demand

The iC-GPC assay (iCubate, Huntsville, AL) provides a molecular option for the rapid, on-demand analysis of positive blood cultures. A preliminary evaluation of the iC-GPC assay using 203 clinical or seeded specimens demonstrated a sensitivity of 93.8% to 100% and a specificity of 98.0% to 100% for the identification of five Gram-positive bacterial species (Staphylococcus aureus,Staphylococcus epidermidis,Streptococcus pneumoniae,Enterococcus faecalis, andEnterococcus faecium) and three associated genetic resistance determinants (mecA,vanA, andvanB) in positive blood culture broths.

scholarly journals Multicenter Evaluation of Rapid BACpro® II for the Accurate Identification of Microorganisms Directly from Blood Cultures Using MALDI-TOF MS

Diagnostics ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2251
Author(s):  
Marina Oviaño ◽  
André Ingebretsen ◽  
Anne K. Steffensen ◽  
Antony Croxatto ◽  
Guy Prod’hom ◽  
...  
Keyword(s):  
Blood Cultures ◽  
Species Level ◽  
Correct Identification ◽  
Gram Positive ◽  
Gram Negative ◽  
Maldi Tof Ms ◽  
Gram Positive Bacteria ◽  
Maldi Tof ◽  
Level Identification ◽  
Tof Ms

The identification of microorganisms directly from blood cultures using MALDI-TOF MS has been shown to be the most impacting application of this methodology. In this study, a novel commercial method was evaluated in four clinical microbiology laboratories. Positive blood culture samples (n = 801) were processed using a rapid BACpro® II kit and then compared with the routine gold standard. A subset of monomicrobial BCs (n = 560) were analyzed in parallel with a Sepsityper® Kit (Bruker Daltonics, Bremen, Germany) and compared with the rapid BACpro® II kit. In addition, this kit was also compared with two different in-house methods. Overall, 80.0% of the monomicrobial isolates (609/761; 95% CI 71.5–88.5) were correctly identified by the rapid BACpro® II kit at the species level (92.3% of the Gram negative and 72.4% of the Gram positive bacteria). The comparison with the Sepsityper® Kit showed that the rapid BACpro® II kit generated higher rates of correct species-level identification for all categories (p > 0.0001), except for yeasts identified with score values > 1.7. It also proved superior to the ammonium chloride method (p > 0.0001), but the differential centrifugation method allowed for higher rates of correct identification for Gram negative bacteria (p > 0.1). The percentage of accurate species-level identification of Gram positive bacteria was particularly noteworthy in comparison with other commercial and in-house methods.

scholarly journals Evaluation of the rapidBACpro® II kit for the rapid identification of microorganisms directly from blood cultures using MALDI-TOF MS

2021 ◽  
Author(s):  
Marina Oviaño ◽  
André Ingebretsen ◽  
Anne K Steffensen ◽  
Antony Croxatto ◽  
Guy Prod’hom ◽  
...  
Keyword(s):  
Blood Cultures ◽  
Species Level ◽  
Correct Identification ◽  
Gram Positive ◽  
Gram Negative ◽  
Maldi Tof Ms ◽  
Gram Positive Bacteria ◽  
Maldi Tof ◽  
Level Identification ◽  
Tof Ms

AbstractObjectivesIdentification of microorganisms directly from blood cultures (BCs) using MALDI-TOF MS has shown to be the application with most impact in this methodology. In this study, a novel commercial method, the rapidBACpro® II, was evaluated in four clinical microbiology laboratories.MethodsPositive blood culture samples (n=801) were processed using the rapidBACpro® II kit and then compared with routine gold standard. A subset of monomicrobial BCs (n=560) were analyzed in parallel with the Sepsityper® kit (Bruker Daltonics, Bremen, Germany) and compared with the rapidBACpro® II kit. In addition, the rapidBACpro® II kit was also compared with two different in-house methods.ResultsOverall, 80.0% of the monomicrobial isolates (609/761) were correctly identified by the rapidBACpro® II kit at the species level (92.3% of the Gram negative and 72.4% of the Gram positive bacteria). The comparison with the Sepsityper® kit yielded higher rates of correct species-level identification provided by the rapidBACpro® II kit for all categories (p>0.0001) except for yeasts identified with score values >1.7. It also proved superior to the ammonium chloride method (p>0.0001) but the differential centrifugation method allowed higher rates of correct identification for Gram negative bacteria (p>0.1).ConclusionsThe rapidBACpro® II kit allowed a high rate of microorganisms correctly identified. The percentage of accurate species-level identification of Gram positive bacteria was particularly noteworthy in comparison with other commercial and in-house methods. This fact was especially interesting in the case of Staphylococcus sp. and Streptococcus sp. in order to elucidate their clinical impact, for example in device-associated bacteremia.

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