Usefulness of Sofia Pneumococcal FIA® test in comparison with BinaxNOW® Pneumococcal test in urine samples for the diagnosis of pneumococcal pneumonia

The Sofia Pneumococcal FIA® test is a recently introduced immunofluorescent assay automatically read aimed to detect Streptococcus pneumoniae antigen in urine. The aim of this study was to evaluate the usefulness of SofiaFIA® urinary antigen test (UAT) in comparison with classical immunochromatographic BinaxNOW® test for the diagnosis of pneumococcal pneumonia (PP). Observational study was conducted in the Hospital Universitari Vall d’Hebron from December 2015 to August 2016. Consecutive adult patients diagnosed of pneumonia and admitted to the emergency department in whom UAT was requested were prospectively enrolled. Paired pneumococcal UAT was performed (BinaxNOW® and SofiaFIA®) in urine samples. To assess the performance of both tests, patients were categorized into proven PP (isolation of S. pneumoniae in sterile fluid) or probable PP (isolation of S. pneumoniae in respiratory secretion). Sensitivity, specificity, and concordance were calculated. A total of 219 patients with pneumonia were enrolled, of whom 14% had a proven or probable PP, 22% a non-pneumococcal etiology, and 64% an unidentified pathogen. Concordance between tests was good (κ?=?0.81). Sensitivity of SofiaFIA® and BinaxNOW® UAT was 78.6 and 50% for proven PP (p?=?0.124), and 74.2 and 58% for proven/probable PP (p?=?0.063). Specificity for both tests was 83.3 and 85.5% for proven and proven/probable PP. In patients without an identified pathogen, SofiaFIA® test was positive in 33 (23.6%) cases and BinaxNOW® in 25 (17.8%), so Sofia Pneumococcal FIA® detected 32.6% more cases than BinaxNOW® (p?=?0.001). Sofia Pneumococcal FIA® test showed an improved sensitivity over visual reading of BinaxNOW® test without a noticeable loss of specificity.     

A prospective study to assess the diagnostic performance of the Sofia® Immunoassay for Influenza and RSV detection.

BackgroundRespiratory viruses RSV and influenza A and B viruses are responsible for important disease outbreaks during the winter season in temperate climate regions. Rapid diagnostic tests (RDTs) are assays designed to yield a rapid diagnosis, which facilitates patient management. The Sofia Influenza A + B Fluorescence Immunoassay and Sofia RSV Fluorescence Immunoassay are RDTs for Influenza and RSV detection that employ a new technology to enhance their sensitivity.ObjectivesSensitivity, specificity and positive and negative predictive values of the assays were calculated compared with the reference diagnostic method: real-time RT-PCR.Study designA prospective evaluation was carried out on 1065 respiratory samples for Sofia Influenza A + B FIA and on 261 samples for Sofia RSV FIA from November 2013 to April 2014.ResultsThe sensitivities of the Sofia Influenza A + B FIA for influenza A and influenza B detection were, respectively, 75.3% (244/324) and 50.0% (8/16). The sensitivity of the Sofia RSV FIA was 92.1% (128/139). There were no differences in Sofia FIA performance depending on the virus subtype.ConclusionsThe results showed high sensitivity and specificity values for influenza A and RSV detection, but values were lower for influenza B. More information is needed regarding the performance for influenza B given the small number of positive samples assessed.     

Performance of a rapid antigen test (Binax NOW® RSV) for diagnosis of respiratory syncytial virus compared with real-time polymerase chain reaction in a pediatric population

BackgroundInfants from Alaska's Yukon–Kuskokwim Delta (YKD) have a high respiratory syncytial virus (RSV) hospitalization rate (104/1000/yr). Appropriate patient management requires rapid and accurate RSV diagnosis. Antigen-based methods are often used in clinical settings, but these tests can lack sensitivity.ObjectiveWe compared Binax NOW^® RSV (BN) used for RSV diagnosis in the YKD hospital with a real-time polymerase chain reaction assay (RT-qPCR) used for viral surveillance.Study designBetween October 2005 and September 2007 we obtained nasopharyngeal washes (NPW) from children <3 years hospitalized with a lower respiratory tract infection. The NPW were tested using BN and RT-qPCR.Results79/311 (25%) children had RSV infection as determined by RT-qPCR. As compared with RT-qPCR, sensitivity and specificity of BN were 72% and 97%, respectively. The sensitivity of BN was higher in children <1 year compared with children ≥1 year (79% vs. 52%; p = 0.025), children with bronchiolitis compared with children without bronchiolitis (89% vs. 38%; p < 0.001), and children with a shorter duration of symptoms before testing (0–1 (92%) vs. 2–4 (78%) vs. 5+ (65%) days; p = 0.04). The median RSV viral load in NPW positive by BN and RT-qPCR was 1.01 × 10⁹ copies/mL vs. a median of 5.25 × 10⁷ copies/mL for NPW positive by RT-qPCR only (p < 0.001).ConclusionRT-qPCR is more sensitive than BN in detecting RSV infection. BN sensitivity is high in children with bronchiolitis, but the sensitivity is low when children present with a non-bronchiolitis illness, especially after a longer duration of symptoms before testing.     

Performance evaluation of EuDx™ ufPCR Flu & RSV detection kit for detection of influenza A/B and respiratory syncytial virus

EuDx? ufPCR Flu & RSV Detection Kit (EUDIPIA, Chungcheongbuk-do, Republic of Korea) is a recently developed molecular assay for simultaneously detecting influenza A/B and respiratory syncytial virus (RSV). We evaluated this assay in a clinical setting and demonstrated its excellent performance for diagnosing influenza A/B and RSV infections.     

Viral agents causing lower respiratory tract infections in hospitalized children: evaluation of the Speed-Oligo? RSV assay for the detection of respiratory syncytial virus

Respiratory syncytial virus (RSV) is the viral agent which is more frequently involved in lower respiratory tract infections (LRTIs) in infants under 1 year of age in developed countries. A new oligochromatographic assay, Speed-Oligo? RSV, was designed and optimized for the specific detection and identification of RSV subtypes A and B. The test was evaluated in 289 clinical samples from 169 hospitalized children using an immunochromatography (IC) test, virus isolation by culture, and an in-house real-time polymerase chain reaction (RT-PCR). Other viruses causing LRTIs were investigated by cell culture or PCR-based tests. Sixty-two patients were infected by RSV (36.7%). In addition, adenovirus, influenza B, parainfluenza 2, and human metapneumovirus were detected in rates ranging from 5 to 8%. A proportion of 10.1% of the patients had mixed infections. The sensitivity, specificity, and positive and negative predictive values were, respectively, 94.9, 99.4, 98.9, and 97.4% for Speed-Oligo? RSV, 92.9, 96.3, 92.9, and 96.3% for RT-PCR/RSV, and 58.4, 98.1, 93.3, and 82.6% for IC. Our rates of viral detection and co-infection were similar to those of previously reported series. Finally, we find that Speed-Oligo? RSV is a rapid and easy-to-perform technique for the detection of RSV and the identification of subtypes A and B.     

Is respiratory syncytial virus one of the causative agents for transient hyperphosphatasemia?

OBJECTIVE: In the winter of 2001, we found several cases of transient hyperphosphatasemia (TH) in patients with respiratory syncytial virus (RSV) infection. Therefore, we tried to verify that RSV was one of the causative agents for TH. RESULTS: From November 2001 to January 2002, we diagnosed 94 cases of RSV infection with the detection of virus antigens in the nasal mucus. Among these cases, we found six cases (6.4%) of TH, and all six patients were over one year of age. There were 55 cases of RSV infection in patients over one year of age, and the rate of TH with RSV infection was estimated to be 10.9% in this age group. This rate of TH (6.4%) was significantly higher than rates reported in previous studies (0.33% to 1.5%, p = 0.0145 to p < 0.0001). CONCLUSION: We conclude that RSV is one of the causative agents for TH.     

The performance of Luminex ARIES® Flu A/B & RSV and Cepheid Xpert® Flu/RSV XC for the detection of influenza A,influenza B,and respiratory syncytial virus in prospective patient samples

BackgroundThe demand for rapid, accurate viral testing has increased the number of assays available for the detection of viral pathogens. One of the newest FDA cleared platforms is the Luminex ARIES^® Flu A/B & RSV, which is a fully automated, real-time PCR-based assay used for detection of influenza A, influenza B, and respiratory syncytial virus (RSV).ObjectivesWe sought to compare the performance of Luminex ARIES^® Flu A/B & RSV assay to the Cepheid Xpert^® Flu/RSV XC assay for rapid Flu and RSV testing.Study designA series of consecutive nasopharyngeal specimens received in the clinical microbiology laboratory during peak influenza season at a major academic center in Chicago, IL, were prospectively tested, using both the ARIES^® Flu A/B & RSV and Xpert^® Flu/RSV XC assays, side by side. Discrepant results were tested on the BioFire FilmArray^® Respiratory Panel for resolution.ResultsA total of 143 consecutive nasopharyngeal specimens, obtained from patients ranging from six months to ninety-three years in age were received between January 1st, 2017 and March 21st, 2017. There was 96.6% agreement between the two assays for detection influenza A, 100% agreement for detection influenza B and RSV, and 98.9% agreement for negative results. The Xpert^® Flu/RSV XC performed with an average turn-around time of approximately 60 min, compared to the ARIES^® Flu A/B & RSV of approximately 120 min. Both assays were equally easy to perform, with a similar amount of hands-on technologist time for each platform.ConclusionsOverall, these results indicate that both tests are comparable in terms of result agreement and technical ease-of-use. The Xpert^® Flu/RSV XC assay did produce results with less turn-around-time, approximately 60 min quicker than the ARIES^® Flu A/B & RSV.     

A controlled comparison of the BacT/ALERT® 3D and VIRTUO™ microbial detection systems

The performance of the next-generation BacT/ALERT® VIRTUO? Microbial Detection System (VIRTUO?, bioMérieux Inc., Hazelwood, MO) was compared to the BacT/ALERT® 3D Microbial Detection System (3D, bioMérieux Inc., Durham, NC) using BacT/ALERT® FA Plus (FA Plus), BacT/ALERT® PF Plus (PF Plus), BacT/ALERT® FN Plus (FN Plus), BacT/ALERT® Standard Aerobic (SA), and BacT/ALERT® Standard Anaerobic (SN) blood culture bottles (bioMérieux Inc., Durham, NC). A seeded limit of detection (LoD) study was performed for each bottle type in both systems. The LoD studies demonstrated that both systems were capable of detecting organisms at nearly identical levels [<10 colony-forming units (CFU) per bottle], with no significant difference. Following LoD determination, a seeded study was performed to compare the time to detection (TTD) between the systems using a panel of clinically relevant microorganisms inoculated at or near the LoD with 0, 4, or 10 mL of healthy human blood. VIRTUO? exhibited a faster TTD by an average of 3.5 h, as well as demonstrated a significantly improved detection rate of 99.9% compared to 98.8% with 3D (p-value <0.05).     

Evaluation of commercial ResPlex II v2.0, MultiCode®-PLx,and xTAG® respiratory viral panels for the diagnosis of respiratory viral infections in adults

BackgroundCommercial multiplex PCR panels for respiratory viruses (PRV) have been recently developed. ResPlex II Panel v2.0 (Qiagen), MultiCode^®-PLx (EraGen Biosciences), and xTAG^® (Luminex) PRV's were studied. All assays detect influenza A and B, adenovirus, parainfluenza 1–3, respiratory syncytial virus A and B, human metapneumovirus and human rhinovirus. The ResPlex II additionally detects coronavirus (229E, OC43, NL63, HKU1), coxsackie/echo virus, bocavirus and differentiates adenoviruses (B, E). The MultiCode-PLX assay detects 229E, OC43, and NL63, differentiates parainfluenza 4a, 4b and adenoviruses (B, C, E). The xTAG additionally subtypes influenza A as seasonal H1 and H3.Study design202 specimens collected from adult patients with signs of respiratory infection from November, 2008 to May, 2009 were used for evaluating the performance of the three commercial PRV assays. Viral culture and xTAG were used as the standards to assess sensitivity and specificity.ResultsThe PRV assays detected more viruses than culture. When compared to culture, the xTAG PRV showed a sensitivity and specificity of 100% and 91%, compared to MultiCode-PLx with 89% and 87%, and ResPlex II with 89% and 94%, respectively. Co-infection was detected in a small subset of patient specimens. Each panel showed differences in sensitivities for individual viruses.ConclusionsWhile the ResPlex II and MultiCode-PLx offer a broader virus detection range and greater ease of use, the xTAG PRV showed increased sensitivity to common viral targets represented in the assays, and also had the ability to differentiate human from non-human influenza A H1.     

Multi-center evaluation of the cobas® Liat® Influenza A/B & RSV assay for rapid point of care diagnosis

Point of Care Testing (POCT) provides the capability for rapid laboratory test results in patient care environments where a traditional clinical laboratory is not available. POCTs have shorter turn-around times (TATs), they may be performed by non-laboratory personnel, and the need for transport time is eliminated. The Food and Drug Administration (FDA) recently granted Clinical Laboratory Improvements Amendment (CLIA) waiver status to the cobas^® Influenza A/B & RSV assay, a rapid, accurate point-of-care test for Influenza and respiratory syncytial virus (RSV) performed on the Liat^® System. The performance characteristics of this test were determined though a multi-site study consisting of different point of care testing environments. Prospectively collected Nasopharyngeal (NP) swabs from 1361 patients seen at 8 primary care clinics and 4 emergency departments (EDs) and 295 retrospectively identified specimens were tested for Influenza A/B and RSV on the cobas^® Liat^® platform. Performance characteristics were determined through comparison to ProFlu+, a laboratory-based PCR test for Influenza A/B and RSV (reference test). Discordant specimens were adjudicated following bi-directional sequencing. The cobas^® Influenza A/B and RSV assay showed sensitivities of 99.6%, 99.3%, and 96.8% for Influenza A, Influenza B, and RSV, respectively as determined from percent positive agreement (PPA) following comparison to the reference test. Sequencing confirmed cobas^® Influenza A/B and RSV results in 49.2% of reference test discordant specimens, while crossing threshold data suggest increased sensitivity compared to the reference test. The cobas^® Influenza A/B and RSV assay was found to be a rapid, sensitive POCT for the detection of these viruses, and provides laboratory-quality PCR-based diagnostic results in point of care settings.     

Evaluation of the combination of the NucliSENS easyMAG® and the EasyQ® applications for the detection of Mycoplasma pneumoniae and Chlamydia pneumoniae in respiratory tract specimens

Mycoplasma pneumoniae and Chlamydia pneumoniae are respiratory tract pathogens frequently involved in community-acquired pneumonia, but are fastidious microorganisms. Their direct detection mainly requires molecular amplification techniques. A nucleic acid extraction system, NucliSENS easyMAG®, and a real-time nucleic acid sequence-based amplification (NASBA) technique, NucliSENS EasyQ®, were recently developed by bioMérieux to detect both bacteria. The aim of our study was to compare the easyMAG/EasyQ combination with our in-house combination, MagNA Pure extraction (Roche) and real-time polymerase chain reaction (PCR), to detect both bacteria in respiratory tract specimens. The analytical specificities of both combinations were similar. A higher analytical sensitivity was found for C. pneumoniae using the easyMAG/EasyQ combination, since the easyMAG/EasyQ system detected nucleic acid extracts 10⁶ times more diluted than the in-house combination. Both combinations were equivalent when detecting M. pneumoniae in positive respiratory tract samples. Finally, the easyMAG/EasyQ combination is a potential useful tool for the detection of both bacteria regarding sensitivity, specificity, monitoring, and standardization of the procedure.     

Comparison of the platelet concentrations obtained in platelet-rich plasma (PRP) between the GPS™ II and GPS™ III systems

Introduction

Platelet growth factors are known for their ability to speed up tissue healing (bone, skin, tendons, muscle). Various techniques make it possible to collect this platelet-rich plasma or PRP.

Methods

This study compares the platelet concentrations obtained from five patients using GPS™ III, which has recently come onto the market, with those obtained using GPS™ II.

Results and conclusion

We obtain a platelet concentration that is six to nine times greater with GPS ™ II and GPS™ III, but there is no significant difference between the concentrations of PRP obtained with the two systems.     

A comparison of Sensititre™ Anaerobe MIC plate with ATB ANA® test for the routine susceptibility testing of common anaerobe pathogens

The accuracy of the Thermo Scientific? Sensititre? Anaerobe MIC plate was assessed against the ATB ANA® test (bioMérieux) on 56 clinically relevant anaerobic strains collected at Geneva University Hospitals. The overall categorical agreement between both methods reached 95%. The Sensititre? Anaerobe MIC plate had excellent accuracy for most antibiotics tested. When the Sensititre? Anaerobe MIC plate disagreed with ATB ANA® test, the gradient strip method resolved the antimicrobial susceptibility categories of all the antibiotics tested, except for piperacillin, piperacillin-tazobactam, and penicillin, in favor of the Sensititre? Anaerobe MIC plate (58% [21 out of 36]). Several very major errors were observed for piperacillin (12.5% [7 out of 56]), piperacillin-tazobactam (12.5% [7 out of 56]), and penicillin (2% [1 out of 56]). The gradient strip method revealed that the categorical differences for piperacillin, piperacillin-tazobactam, and penicillin were at least partly explained by heterogeneity in resistance expression. The Sensititre? Anaerobe MIC plate offers therefore a useful alternative to the ATB ANA® test for the routine antimicrobial susceptibility testing of anaerobes in clinical microbiology laboratories.     

Conserved nucleotides in the terminus of the 3′ UTR region are important for the replication and infectivity of porcine reproductive and respiratory syndrome virus

The 3′ untranslated region (3′ UTR), including the poly (A) tail, reportedly plays an important role in arterivirus replication, but the roles of the cis-acting elements present in the 3′ UTR of porcine reproductive and respiratory syndrome virus (PRRSV) remain largely unknown. In the present study, PCR-based mutagenic analysis was conducted on the 3′ UTR of PRRSV infectious full-length cDNA clone pAPRRS to investigate the structure and function of the conserved terminal nucleotides between the poly (A) tail and the 3′ UTR region. Our findings indicated that the conservation of the primary sequence of the 3′ terminal nucleotides, rather than the surrounding secondary structure, was vital for viral replication and infectivity. Four nucleotides (nt) (5′-¹⁵⁵¹⁷AAUU¹⁵⁵²⁰-3′) at the 3′ proximal end of the 3′ UTR and the dinucleotide 5′-AU-3′ exerted an important regulatory effect on viral viability. Of the five 3′-terminal nucleotides of the 3′ UTR (5′-¹⁵⁵⁰³AACCA¹⁵⁵⁰⁷-3′), at least three, including the last dinucleotide (5′-CA-3′), were essential for maintaining viral infectivity. Taken together, the 3′-terminal conserved sequence plays a critical role in PRRSV replication and may function as a contact site for specific assembly of the replication complex.