scholarly journals Multicenter Clinical Evaluation of the Automated Aries Group A Strep PCR Assay from Throat Swabs

2018 ◽  
Vol 57 (2) ◽  
Author(s):  
N. Kanwar ◽  
J. Crawford ◽  
C. Ulen ◽  
T. S. Uphoff ◽  
J. Dien Bard ◽  
...  
Keyword(s):  
Predictive Value ◽  
Throat Swab ◽  
False Negative ◽  
Reference Method ◽  
The United States ◽  
Antibiotic Administration ◽  
Pcr Assay ◽  
Assay Sensitivity ◽  
Content Type ◽  
Group A

ABSTRACT Group A Streptococcus (GAS) is one of the leading causes of bacterial pharyngitis. Early GAS diagnosis is critical for appropriate antibiotic administration that reduces the risk of GAS sequelae and limits spread of the infection. The Aries Group A Strep (GAS) assay (Luminex, Austin, TX) is a fully automated PCR assay for direct detection of GAS in throat swab specimens in less than 2 h with minimum hands-on time. This multicenter prospective study evaluated the clinical performance of the Aries GAS assay compared to that of Streptococcus pyogenes culture. Subjects with symptoms consistent with pharyngitis were enrolled across four sites in the United States, and a throat swab in liquid Amies medium was obtained. Aries and reference testing was performed within 72 and 48 h after sample collection, respectively. Of 623 throat swab specimens from patients with pharyngitis (93.6% <18 years old, 54.3% female), the reference method yielded valid results for 618 specimens. Reference and Aries assay testing showed GAS-positive results for 160 (25.9%) and 166 (26.9%) specimens, respectively. Compared to the reference method, Aries assay sensitivity was 97.5% (95% confidence interval [CI], 93.7% to 99.0%), specificity was 97.8% (95% CI, 96.0 to 98.8%), positive predictive value was 94.0% (95% CI, 89.3% to 96.7%), and negative predictive value was 99.1% (95% CI, 97.7% to 99.7%). There were 10 false-positive and four false-negative detections with the Aries assay. Discrepant analysis with bidirectional sequencing yielded concordant results with the Aries assay for nine of 14 discordant samples. The Aries assay had high sensitivity and specificity for qualitative detection of group A Streptococcus from patients with pharyngitis.

scholarly journals Multicenter Clinical Evaluation of the Revogene Strep A Molecular Assay for Detection of Streptococcus pyogenes from Throat Swab Specimens

2020 ◽  
Vol 58 (7) ◽  
Author(s):  
D. Banerjee ◽  
J. Michael ◽  
B. Schmitt ◽  
H. Salimnia ◽  
N. Mhaissen ◽  
...  
Keyword(s):  
Sensitivity And Specificity ◽  
Predictive Value ◽  
Throat Swab ◽  
Pediatric Population ◽  
False Negative ◽  
Reference Method ◽  
Gas Detection ◽  
Quebec City ◽  
Molecular Assay ◽  
Assay Sensitivity

ABSTRACT Group A streptococcus (GAS) species cause bacterial pharyngitis in both adults and children. Early and accurate diagnosis of GAS is important for appropriate antibiotic therapy to prevent GAS sequalae. The Revogene Strep A molecular assay (Meridian Bioscience Canada Inc, Quebec City, QC, Canada) is an automated real-time PCR assay for GAS detection from throat swab specimens within approximately 70 min. This multicenter prospective study evaluated the performance of the Revogene Strep A molecular assay compared to that of bacterial culture. Dual throat swab specimens in either liquid Amies or Stuart medium were collected from eligible subjects (pediatric population and adults) enrolled across 7 sites (USA and Canada). Revogene Strep A and reference testing was performed within 7 days and 48 h of sample collection, respectively. Of the 604 evaluable specimens, GAS was detected in 154 (25.5%) samples by the reference method and in 175 (29%) samples by the Revogene Strep A assay. Revogene Strep A assay sensitivity and specificity were reported to be 98.1% (95% confidence interval [CI], 94.4 to 99.3) and 94.7% (95% CI, 92.2 to 96.4), respectively. The positive predictive value was 86.3% (95% CI, 80.4 to 90.6), negative predictive value was 99.3% (95% CI, 98.0 to 99.8) with a 1.0% invalid rate. Discrepant analysis with alternative PCR/bidirectional sequencing was performed for 24 false-positive (FP) and 3 false-negative (FN) specimens. Concordant results were reported for 17 (FP only) of 27 discordant specimens. The Revogene Strep A assay had high sensitivity and specificity for GAS detection and provides a faster alternative for GAS diagnosis.

scholarly journals Evaluation of Level of Agreement in Bordetella Species Identification in Three U.S. Laboratories during a Period of Increased Pertussis

2015 ◽  
Vol 53 (6) ◽  
pp. 1842-1847 ◽  
Author(s):  
Brunilís Burgos-Rivera ◽  
Adria D. Lee ◽  
Katherine E. Bowden ◽  
Amanda E. Faulkner ◽  
Brent L. Seaton ◽  
...  
Keyword(s):  
Species Identification ◽  
Insertion Sequence ◽  
The United States ◽  
Pcr Assay ◽  
Assay Sensitivity ◽  
Content Type ◽  
Negative Results ◽  
Relative Contribution ◽  
Level Of Agreement ◽  
Good Agreement

While PCR is the most common method used for detectingBordetella pertussisin the United States, most laboratories use insertion sequence481(IS481), which is not specific forB. pertussis; therefore, the relative contribution of otherBordetellaspecies is not understood. The objectives of this study were to evaluate the proportion of otherBordetellaspecies misidentified asB. pertussisduring a period of increased pertussis incidence, determine the level of agreement inBordetellaspecies detection between U.S. commercial laboratories and the CDC, and assess the relative diagnostic sensitivity of CDC's PCR assay when using a different PCR master mix. Specimens collected between May 2012 and May 2013 were tested at two U.S. commercial laboratories forB. pertussisandB. parapertussisdetection. Every fifth specimen positive for IS481and/or IS1001with cycle threshold (CT) values of ≤35 was sent to CDC for PCR testing that identifiesBordetellaspecies. Specimens with indeterminate or negative results in the CDC PCR were tested using an alternate PCR master mix. Of 755 specimens, there was agreement in species identification for 83.4% (n= 630). Of the specimens with different identifications (n= 125), 79.2% (n= 99) were identified as indeterminateB. pertussisat CDC. Overall, 0.66% (n= 5) of the specimens were identified asB. holmesiiorB. bronchisepticaat CDC. Of 115 specimens with indeterminate or negative results, 46.1% (n= 53) wereB. pertussispositive when tested by an alternate master mix, suggesting a possible increase in assay sensitivity. This study demonstrates good agreement between the two U.S. commercial laboratories and CDC and little misidentification ofBordetellaspecies during the 2012 U.S. epidemic.

scholarly journals Evaluation of the illumigene Mycoplasma Direct DNA Amplification Assay

2018 ◽  
Vol 56 (7) ◽  
Author(s):  
Neena Kanwar ◽  
Morgan A. Pence ◽  
Donna Mayne ◽  
Jeffrey Michael ◽  
Rangaraj Selvarangan
Keyword(s):  
Direct Detection ◽  
False Negative ◽  
Reference Method ◽  
Dna Amplification ◽  
The United States ◽  
Community Acquired Pneumonia ◽  
Content Type ◽  
Amplification Assay ◽  
Respiratory Specimens

ABSTRACT Mycoplasma pneumoniae is a common cause of community-acquired pneumonia. The illumigene Mycoplasma Direct (iMD) DNA amplification assay is a qualitative in vitro test utilizing loop-mediated isothermal amplification (LAMP) technology for the direct detection of M. pneumoniae DNA in respiratory specimens. The iMD assay does not require the preextraction of nucleic acids from specimens, which is a prerequisite step for the previously approved illumigene Mycoplasma (iM) assay. The aim of this prospective multicenter study was to evaluate the performance characteristics of the newly developed iMD assay, compared with the iM assay. Subjects with symptoms of upper respiratory illnesses suggesting M. pneumoniae infection were enrolled at three sites in the United States. Respiratory specimens were obtained using dual throat swabs. One swab was tested with the iMD assay at each enrollment site. Reference testing with the iM assay was performed by the manufacturer. Among 456 specimens tested, the iM reference method detected M. pneumoniae in 25 specimens (5.5%), while the iMD assay identified 34 specimens (7.5%) as M. pneumoniae positive. There were 10 false-positive results and 1 false-negative result with the iMD assay. The overall positive and negative agreement rates were 96.0% (95% confidence interval [CI], 80.5 to 99.3%) and 97.7% (95% CI, 95.8 to 98.7%), respectively. The overall agreement rate was determined to be 97.6% (95% CI, 95.7 to 98.6%). We conclude that the iMD test results were comparable to the iM assay results. The removal of the DNA extraction step for the iMD assay simplifies testing, saves time, and reduces the costs of detecting M. pneumoniae from throat swabs, compared to the iM assay.

scholarly journals Evaluation of the Carba NP Test for Rapid Detection of Carbapenemase-Producing Enterobacteriaceae and Pseudomonas aeruginosa

2013 ◽  
Vol 57 (9) ◽  
pp. 4578-4580 ◽  
Author(s):  
Nathalie Tijet ◽  
David Boyd ◽  
Samir N. Patel ◽  
Michael R. Mulvey ◽  
Roberto G. Melano
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Positive Predictive Value ◽  
Negative Predictive Value ◽  
Predictive Value ◽  
Rapid Detection ◽  
False Negative ◽  
Bacterial Extract ◽  
Content Type ◽  
Negative Results ◽  
False Negative Results

ABSTRACTThe Carba NP test was evaluated against a panel of 244 carbapenemase- and non-carbapenemase-producingEnterobacteriaceaeandPseudomonas aeruginosaisolates. We confirmed the 100% specificity and positive predictive value of the test, but the sensitivity and negative predictive value were 72.5% and 69.2%, respectively, and increased to 80% and 77.3%, respectively, using a more concentrated bacterial extract. False-negative results were associated with mucoid strains or linked to enzymes with low carbapenemase activity, particularly OXA-48-like, which has emerged globally in enterobacteria.

scholarly journals Updating Molecular Diagnostics for Detecting Methicillin-Susceptible and Methicillin-Resistant Staphylococcus aureus Isolates in Blood Culture Bottles

2019 ◽  
Vol 57 (11) ◽  
Author(s):  
Fred C. Tenover ◽  
Isabella A. Tickler ◽  
Victoria M. Le ◽  
Scott Dewell ◽  
Rodrigo E. Mendes ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Blood Culture ◽  
False Negative ◽  
The United States ◽  
Molecular Diagnostic ◽  
Methicillin Resistant ◽  
Content Type ◽  
Target Nucleic Acid ◽  
Antimicrobial Resistance Genes

ABSTRACT Molecular diagnostic tests can be used to provide rapid identification of staphylococcal species in blood culture bottles to help improve antimicrobial stewardship. However, alterations in the target nucleic acid sequences of the microorganisms or their antimicrobial resistance genes can lead to false-negative results. We determined the whole-genome sequences of 4 blood culture isolates of Staphylococcus aureus and 2 control organisms to understand the genetic basis of genotype-phenotype discrepancies when using the Xpert MRSA/SA BC test (in vitro diagnostic medical device [IVD]). Three methicillin-resistant S. aureus (MRSA) isolates each had a different insertion of a genetic element in the staphylococcal cassette chromosome (SCCmec)-orfX junction region that led to a misclassification as methicillin-susceptible S. aureus (MSSA). One strain contained a deletion in spa, which produced a false S. aureus-negative result. A control strain of S. aureus that harbored an SCCmec element but no mecA (an empty cassette) was correctly called MSSA by the Xpert test. The second control contained an SCCM1 insertion. The updated Xpert MRSA/SA BC test successfully detected both spa and SCCmec variants of MRSA and correctly identified empty-cassette strains of S. aureus as MSSA. Among a sample of 252 MSSA isolates from the United States and Europe, 3.9% contained empty SCCmec cassettes, 1.6% carried SCCM1, <1% had spa deletions, and <1% contained SCCmec variants other than those with SCCM1. These data suggest that genetic variations that may interfere with Xpert MRSA/SA BC test results remain rare. Results for all the isolates were correct when tested with the updated assay.

scholarly journals Performance and Verification of a Real-Time PCR Assay Targeting thegyrAGene for Prediction of Ciprofloxacin Resistance in Neisseria gonorrhoeae: TABLE 1

2016 ◽  
Vol 54 (3) ◽  
pp. 805-808 ◽  
Author(s):  
P. Hemarajata ◽  
S. Yang ◽  
O. O. Soge ◽  
R. M. Humphries ◽  
J. D. Klausner
Keyword(s):  
Neisseria Gonorrhoeae ◽  
Real Time ◽  
Real Time Pcr ◽  
The United States ◽  
Test Results ◽  
Pcr Assay ◽  
Content Type ◽  
Agar Dilution ◽  
Ciprofloxacin Resistance ◽  
To Receive

In the United States, 19.2% ofNeisseria gonorrhoeaeisolates are resistant to ciprofloxacin. We evaluated a real-time PCR assay to predict ciprofloxacin susceptibility using residual DNA from the Roche Cobas 4800 CT/NG assay. The results of the assay were 100% concordant with agar dilution susceptibility test results for 100 clinical isolates. Among 76 clinical urine and swab specimens positive forN. gonorrhoeaeby the Cobas assay, 71% could be genotyped. The test took 1.5 h to perform, allowing the physician to receive results in time to make informed clinical decisions.

scholarly journals Rapid Detection of Acquired and Inducible Clarithromycin Resistance in Mycobacterium abscessus Group by a Simple Real-Time PCR Assay

2015 ◽  
Vol 53 (7) ◽  
pp. 2337-2339 ◽  
Author(s):  
Robert F. Luo ◽  
Cheyenne Curry ◽  
Nathan Taylor ◽  
Indre Budvytiene ◽  
Niaz Banaei
Keyword(s):  
Nucleic Acid ◽  
Real Time ◽  
Real Time Pcr ◽  
Rapid Detection ◽  
Mycobacterium Abscessus ◽  
Nucleic Acid Testing ◽  
Pcr Assay ◽  
Content Type ◽  
Clarithromycin Resistance ◽  
Group A

By targeting theerm(41) andrrlgenes in theMycobacterium abscessusgroup, a multiplex real-time PCR assay for clarithromycin resistance showed 95% (38/40) concordance with nucleic acid testing and 95% (37/39) concordance with phenotypic testing. This assay provides a simple and rapid alternative to extended incubation orerm(41) sequencing.

scholarly journals Modern understanding about the role of group A β -hemolytic streptococcus in acute tonsillitis

2021 ◽  
Vol 13 (4) ◽  
pp. 66-71
Author(s):  
N. T. Mirzoev ◽  
S. N. Sidorchuk ◽  
Yu. I. Bulan’kov ◽  
K. V. Kas’janenko
Keyword(s):  
Predictive Value ◽  
Bacterial Culture ◽  
Detection Method ◽  
Throat Swab ◽  
Diagnostic System ◽  
Antigen Detection ◽  
Acute Tonsillitis ◽  
Hemolytic Streptococcus ◽  
Streptococcal Antigen ◽  
Group A

Objective: assess the modern value of group А β-hemolytic streptococcus in patients with acute tonsillitis and the effectiveness of the rapid streptococcal antigen detection method.Materials and methods: microbial landscape assessment of acute tonsillitis was based on retrospective analysis of 902 bacterial culture results of a throat swab of patients with syndromes of acute tonsillitis treated in the Infectious Diseases Clinic of the Military Medical Academy named after S.M. Kirov during the period of 2019-2020. The effectiveness of the rapid streptococcal antigen detection method in the oropharynx was determined by a prospective study involving 35 patients with acute tonsillitis.Results: in the study, we have found that bacterial culture results of a throat swab, the following were more common: Nesseria species (39 %), Streptococcus viridans (23 %), and Staphylococcus aureus (17 %). The frequency of detection of β-hemolytic streptococcus was 1 %. The rapid diagnostic system «Streptatest» in patients with acute tonsillitis has demonstrated efficiency, under which that sensitivity of test was 80 %, specificity – 90 %, positive predictive value – 57,14 %, negative predictive value – 96,43 %.Conclusions: the frequency of group A β-hemolytic streptococcus in patients with lesion of lymphoid tissues of the oropharynx has declined significantly nowadays. The rapid diagnostic system «Streptatest» is a highly effective medical product that can be used in both hospital and pre-hospital stage. 

US pressure weakens Syria-based Khorasan Group

2015 ◽  
Keyword(s):  
United States ◽  
The United States ◽  
Terrorist Attacks ◽  
Islamic State ◽  
The West ◽  
Content Type ◽  
The Us ◽  
Group A ◽  
Imminent Threat ◽  
State Group

Subject Assessment of the 'Khorasan Group' Significance The US-led coalition's airstrikes in Syria since 2014 have focused on the Islamic State group (ISG). However, they have also struck the 'Khorasan Group' -- a collection of veteran al-Qaida operatives that allegedly plots terrorist attacks abroad, and that operates on the edges of Syria's al-Qaida affiliate, Jabhat al-Nusra (JaN). Beginning in late 2014, Washington warned repeatedly that the Khorasan Group was plotting attacks in Europe and the United States, and that it was recruiting holders of Western passports who would be able to enter and transit Western countries more easily. Impacts Al-Qaida outside Syria will likely pursue terrorist attacks that punish the West for its policies in the Muslim world. ISG will also carry out terrorist attacks in an effort to assert its leadership over the global jihadist movement. Without an imminent threat from the Khorasan Group, the West will have difficulty making a case for targeting JaN. JaN will retain a base of Syrian opposition support so long as it does not invite international retaliation by supporting an attack abroad.

scholarly journals Molecular Testing for Mycoplasma genitalium in the United States: Results from the AMES Prospective Multicenter Clinical Study

2019 ◽  
Vol 57 (11) ◽  
Author(s):  
Charlotte A. Gaydos ◽  
Lisa E. Manhart ◽  
Stephanie N. Taylor ◽  
Rebecca A. Lillis ◽  
Edward W. Hook ◽  
...  
Keyword(s):  
United States ◽  
Clinical Study ◽  
Reference Method ◽  
Mycoplasma Genitalium ◽  
The United States ◽  
23S Rrna ◽  
Molecular Testing ◽  
Content Type ◽  
Vaginal Swabs ◽  
Multicenter Clinical Study

ABSTRACT A prospective multicenter clinical study involving subjects from 21 sites across the United States was conducted to validate the performance of a new in vitro diagnostic nucleic acid amplification test (NAAT) for the detection of Mycoplasma genitalium. Seven urogenital specimen types (n = 11,556) obtained from 1,778 females, aged 15 to 74 years, and 1,583 males, aged 16 to 82 years, were tested with the Aptima Mycoplasma genitalium assay, an investigational transcription-mediated amplification (TMA) NAAT for the detection of M. genitalium 16S rRNA. Infected status for enrolled subjects was established using results obtained from testing either self-collected vaginal swab or clinician-collected male urethral swab specimens with a composite reference method consisting of three transcription-mediated amplification NAATs targeting unique regions of M. genitalium 16S or 23S rRNA. M. genitalium prevalence was 10.2% in females and 10.6% in males; prevalence was high in both symptomatic and asymptomatic subjects for both sexes. Compared to the subject infected status standard, the investigational test had sensitivity and specificity estimates, respectively, of 98.9% and 98.5% for subject-collected vaginal swabs, 92.0% and 98.0% for clinician-collected vaginal swabs, 81.5% and 98.3% for endocervical swabs, 77.8% and 99.0% for female urine, and 98.2% and 99.6% for male urethral swabs, 88.4% and 97.8% for self-collected penile meatal swabs, and 90.9% and 99.4% for male urine specimens. For all seven specimen types, within-specimen positive and negative agreements between the investigational test and the composite reference standard ranged from 94.2% to 98.3% and from 98.5 to 99.9%, respectively. These results provide clinical efficacy evidence for the first FDA-cleared NAAT for M. genitalium detection in the United States.

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