Clinical Validation of the Xpert MTB/RIF test for Identification of the MTB Complex in AFB Smear-Positive MGIT broth cultures

2022 ◽  
Author(s):  
Derek T. Armstrong ◽  
Stefanie Fisher ◽  
Marissa Totten ◽  
Matthew Schwartz ◽  
Devasena Gnanashanmugam ◽  
...  
Keyword(s):  
Hospital Setting ◽  
High Sensitivity ◽  
The United States ◽  
Rapid Identification ◽  
Cross Reactivity ◽  
Rifampicin Resistance ◽  
Becton Dickinson ◽  
Rapid Replacement ◽  
Rifampin Resistance ◽  
Positive Results

The identification of the M. tuberculosis complex (MTBC) from smear positive broth cultures can be achieved using several methods including both lab-developed and commercially available molecular assays. In the United States, a commercially available probe-based assay has been used for over a decade by many laboratories for identification of MTBC directly from AFB smear positive broth cultures, including those recovered from the MGIT 960 system. However, recent difficulties in obtaining probe kits for identification resulted in mycobacteriology laboratories looking for alternative platforms to provide for rapid identification of MTBC and detection of rifampicin resistance. The Xpert® MTB/RIF test (Cepheid, Sunnyvale, Ca) has shown high sensitivity for the diagnosis of MTBC from pulmonary specimens but is not often used for identification directly from smear positive, MGIT 960 broth cultures (Becton Dickinson, Sparks, Md). We sought to validate the Xpert MTB/RIF test for use with AFB smear positive MGIT 960 cultures in a clinical hospital setting. Overall, the assay showed a categorical agreement of 100% for identification of MTBC and detection of rifampin resistance. No false positive results or cross-reactivity were noted. Findings indicate that the Xpert MTB/RIF test may be suitable as a rapid replacement for identification of MTBC and detection of rifampicin resistance from AFB smear positive MGIT 960 broth cultures.

scholarly journals Ability To Serologically Confirm Recent Zika Virus Infection in Areas with Varying Past Incidence of Dengue Virus Infection in the United States and U.S. Territories in 2016

2017 ◽  
Vol 56 (1) ◽  
Author(s):  
Nicole P. Lindsey ◽  
J. Erin Staples ◽  
Krista Powell ◽  
Ingrid B. Rabe ◽  
Marc Fischer ◽  
...  
Keyword(s):  
Puerto Rico ◽  
Virus Infection ◽  
Dengue Virus ◽  
Zika Virus ◽  
Denv Infection ◽  
The United States ◽  
American Samoa ◽  
Cross Reactivity ◽  
Immunoglobulin M ◽  
Positive Results

ABSTRACTCross-reactivity within flavivirus antibody assays, produced by shared epitopes in the envelope proteins, can complicate the serological diagnosis of Zika virus (ZIKAV) infection. We assessed the utility of the plaque reduction neutralization test (PRNT) to confirm recent ZIKAV infections and rule out misleading positive immunoglobulin M (IgM) results in areas with various levels of past dengue virus (DENV) infection incidence. We reviewed PRNT results of sera collected for diagnosis of ZIKAV infection from 1 January through 31 August 2016 with positive ZIKAV IgM results, and ZIKAV and DENV PRNTs were performed. PRNT result interpretations included ZIKAV, unspecified flavivirus, DENV infection, or negative. For this analysis, ZIKAV IgM was considered false positive for samples interpreted as a DENV infection or negative. In U.S. states, 208 (27%) of 759 IgM-positive results were confirmed to be ZIKAV compared to 11 (21%) of 52 in the U.S. Virgin Islands (USVI), 15 (15%) of 103 in American Samoa, and 13 (11%) of 123 in Puerto Rico. In American Samoa and Puerto Rico, more than 80% of IgM-positive results were unspecified flavivirus infections. The false-positivity rate was 27% in U.S. states, 18% in the USVI, 2% in American Samoa, and 6% in Puerto Rico. In U.S. states, the PRNT provided a virus-specific diagnosis or ruled out infection in the majority of IgM-positive samples. Almost a third of ZIKAV IgM-positive results were not confirmed; therefore, providers and patients must understand that IgM results are preliminary. In territories with historically higher rates of DENV transmission, the PRNT usually could not differentiate between ZIKAV and DENV infections.

scholarly journals Genetic Change Within Populations of Phytophthora infestans in the United States and Canada During 1994 to 1996: Role of Migration and Recombination

1998 ◽  
Vol 88 (9) ◽  
pp. 939-949 ◽  
Author(s):  
Stephen B. Goodwin ◽  
Christine D. Smart ◽  
Robert W. Sandrock ◽  
Kenneth L. Deahl ◽  
Zamir K. Punja ◽  
...  
Keyword(s):  
United States ◽  
Sexual Reproduction ◽  
Phytophthora Infestans ◽  
High Sensitivity ◽  
The United States ◽  
Rapid Identification ◽  
Mating Types ◽  
Long Distance ◽  
New Genotype ◽  
The Us

Dramatic changes occurred within populations of Phytophthora infestans in the United States and Canada from 1994 through 1996. Occurrence of the US-8 genotype, detected rarely during 1992 and 1993, increased rapidly and predominated in most regions during 1994 through 1996. US-7, which infected both potato and tomato and made up almost 50% of the sample during 1993, was detected only rarely among 330 isolates from the United States analyzed during 1994. It was not detected at all in more limited samples from 1996. Thus, ability to infect both potato and tomato apparently did not increase the fitness of this genotype relative to US-8, as predicted previously. US-1, the previously dominant genotype throughout the United States and Canada, made up 8% or less of the samples analyzed during 1994 through 1996. A few additional genotypes were detected, which could indicate the beginnings of sexual reproduction of P. infestans within the United States and Canada. However, clonal reproduction still predominated in all locations sampled; opportunities for sexual reproduction probably were limited, because the A1 and A2 mating types usually were separated geographically. The high sensitivity of the US-1 genotype to the fungicide metalaxyl also could have reduced opportunities for contact between the mating types in fields where this compound was applied. The previous correlation between metalaxyl sensitivity and genotype was confirmed and extended to a new genotype, US-17: all US-1 isolates tested were sensitive; all isolates of the US-7, US-8, and US-17 genotypes tested to date have been resistant. Isolates of P. capsici and P. erythroseptica, two other species often found on tomato and potato, could be easily distinguished from each other and from P. infestans using a simple allozyme assay for the enzyme glucose-6-phosphate isomerase. This technique could be useful for rapid identification of species, in addition to genotype of P. infestans. It generally was not possible to predict which genotypes would be present in a location from 1 year to the next. Long-distance movement of US-8 in seed tubers was documented, and this was probably the primary means for the rapid spread of this genotype from 1993 through 1996.

scholarly journals Development of an Immunochromatographic Assay Kit Using Fluorescent Silica Nanoparticles for Rapid Diagnosis of Acanthamoeba Keratitis

2014 ◽  
Vol 53 (1) ◽  
pp. 273-277 ◽  
Author(s):  
Koji Toriyama ◽  
Takashi Suzuki ◽  
Tomoyuki Inoue ◽  
Hiroshi Eguchi ◽  
Saichi Hoshi ◽  
...  
Keyword(s):  
Silica Nanoparticles ◽  
Real Time ◽  
Real Time Pcr ◽  
High Sensitivity ◽  
Acanthamoeba Keratitis ◽  
Cross Reactivity ◽  
Immunochromatographic Assay ◽  
Content Type ◽  
Fluorescent Silica Nanoparticles ◽  
Positive Results

We developed an immunochromatographic assay kit that uses fluorescent silica nanoparticles bound to anti-Acanthamoebaantibodies (fluorescent immunochromatographic assay [FICGA]) and evaluated its efficacy for the detection ofAcanthamoebaand diagnosis ofAcanthamoebakeratitis (AK). The sensitivity of the FICGA kit was evaluated using samples ofAcanthamoebatrophozoites and cysts diluted to various concentrations. A conventional immunochromatographic assay kit with latex labels (LICGA) was also evaluated to determine its sensitivity in detectingAcanthamoebatrophozoites. To check for cross-reactivity, the FICGA was performed by using samples of other common causative pathogens of infectious keratitis, such asPseudomonas aeruginosa,Staphylococcus aureus,Staphylococcus epidermidis, andCandida albicans. Corneal scrapings from patients with suspected AK were tested with the FICGA kit to detect the presence ofAcanthamoeba, and the results were compared with those of real-time PCR. The FICGA kit detected organisms at concentrations as low as 5 trophozoites or 40 cysts per sample. There were no cross-reactivities with other pathogens. The FICGA was approximately 20 times more sensitive than the LICGA for the detection ofAcanthamoebatrophozoites. The FICGA kit yielded positive results for all 10 patients, which corresponded well with the real-time PCR results. The FICGA kit demonstrated high sensitivity for the detection ofAcanthamoebaand may be useful for the diagnosis of AK.

scholarly journals Use of Oral Fluid in a Rapid Syphilis Test Assay

2017 ◽  
Vol 4 (suppl_1) ◽  
pp. S107-S108 ◽  
Author(s):  
Chelsea Shannon ◽  
Claire Bristow ◽  
Sasha Herbst De Cortina ◽  
Jennifer Chang ◽  
Jeffrey Klausner
Keyword(s):  
Whole Blood ◽  
Oral Fluid ◽  
Point Of Care ◽  
Fluid Collection ◽  
Treponema Pallidum ◽  
Rapid Test ◽  
High Sensitivity ◽  
The United States ◽  
Collection Device ◽  
Positive Results

Abstract Background From 2014 to 2015, the syphilis rate in the United States increased by 19%, reaching its highest rate since 1994. Currently, point-of-care syphilis assays use fingerstick or venipuncture whole blood to identify Treponema pallidum (TP) antibodies by qualitative immunoassay. However, patients and providers prefer oral fluid testing to whole blood testing. In this study, we aimed to determine whether a rapid syphilis test intended for use on whole blood could be used to detect TP antibodies in oral fluid. Methods Oral fluid was collected from 72 participants using the Super•SAL™ Oral Fluid Collection Device (Oasis Diagnostics®, Vancouver, WA). The device uses an absorbent cylindrical pad to collect and filter ~1 mlml of oral fluid. Oral fluid filtrate was tested using the SD Bioline Syphilis 3.0 rapid test (Alere Diagnostics, MA) following manufacturer directions for whole blood. TP particle agglutination (TPPA) and rapid plasma reagin (RPR) results derived from participants’ medical records were used as reference values. We used three different definitions as comparators: 1: TPPA reactive; 2: TPPA and RPR reactive and 3: TPPA reactive and RPR titer >1:4. Those with non-reactive TPPA and RPR results were considered seronegative. We calculated the sensitivity and specificity for definition 1 and sensitivity for definitions 2 and 3. We used the exact binomial method to determine 95% confidence intervals (CI). Results With definitions 1, 2, and 3, respectively, sensitivity was 83.3% (CI: 67.2, 93.6), 86.4% (CI: 65.1, 97.1), and 100% (CI: 71.5, 100). Specificity was 47.2% (CI: 36.5, 75.5). Conclusion The high sensitivity of the SD Bioline Syphilis 3.0 test using oral fluid suggests a strong potential for the development of accurate rapid oral syphilis tests. Sensitivity increased with higher RPR titer. False positive results may be due to the presence of non-venereal treponemal antibodies in oral fluid. Further research and development are needed to optimize specificity. Disclosures All authors: No reported disclosures.

scholarly journals Shortened Time to IdentifyStaphylococcusSpecies from Blood Cultures and Methicillin Resistance Testing Using CHROMAgar

2009 ◽  
Vol 2009 ◽  
pp. 1-3 ◽  
Author(s):  
Shingo Chihara ◽  
Mary K. Hayden ◽  
Eileen Minogue-Corbett ◽  
Kamaljit Singh
Keyword(s):  
Methicillin Resistance ◽  
Rapid Identification ◽  
Blood Cultures ◽  
Resistance Testing ◽  
Coagulase Negative Staphylococcus ◽  
Becton Dickinson ◽  
Antibiotic Selection ◽  
Empiric Antibiotic ◽  
Positive Results ◽  
Gram Positive Cocci

The ability to rapidly differentiate coagulase-negative staphylococcus (CoNS) fromStaphylococcus aureusand to determine methicillin resistance is important as it affects the decision to treat empiric antibiotic selection. The objective of this study was to evaluate CHROMagarS. aureusand CHROMagar MRSA (Becton Dickinson) for rapid identification ofStaphylococcusspp. directly from blood cultures. Consecutive blood culture bottles (BacT Alert 3D SA and SN, bioMérieux) growing gram-positive cocci in clusters were evaluated. An aliquot was plated onto CHROMagar MRSA (C-MRSA) and CHROMagarS. aureus(C-SA) plates, which were read at 12 to 16 hours. C-SA correctly identified 147/147S. aureus(100% sensitivity); 2 CoNS were misidentified asS. aureus(98% specificity). C-MRSA correctly identified 74/77 MRSA (96% sensitivity). None of the MSSA isolates grew on C-MRSA (100% specificity). In conclusion, CHROMagar is a rapid and sensitive method to distinguish MRSA, MSSA, and coagulase-negativeStaphylococcusand may decrease time of reporting positive results.

scholarly journals Thrombotic Thrombocytopenia after COVID-19 Vaccination: In Search of the Underlying Mechanism

Vaccines ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 559
Author(s):  
Piotr Rzymski ◽  
Bartłomiej Perek ◽  
Robert Flisiak
Keyword(s):  
Direct Interaction ◽  
Underlying Mechanism ◽  
The United States ◽  
Cross Reactivity ◽  
Spike Protein ◽  
Vaccine Hesitancy ◽  
Future Research ◽  
Platelet Factor ◽  
Precautionary Measures ◽  
Adenoviral Proteins

The rollout of COVID-19 vaccines brings hope for successful pandemic mitigation and getting the transmission of SARS-CoV-2 under control. The vaccines authorized in Europe displayed a good safety profile in the clinical trials. However, during their post-authorization use, unusual thrombotic events associated with thrombocytopenia have rarely been reported for vector vaccines. This led to the temporary suspension of the AZD1222 vaccine (Oxford/AstraZeneca) in various European countries and the Ad26.COV2 vaccine (Janssen/Johnson&Johnson) in the United States, with regulatory bodies launching investigations into potential causal associations. The thromboembolic reactions were also rarely reported after mRNA vaccines. The exact cause of these adverse effects remains to be elucidated. The present paper outlines the hypotheses on the mechanisms behind the very rare thrombotic thrombocytopenia reported after the COVID-19 vaccination, along with currently existing evidence and future research prospects. The following are discussed: (i) the role of antibodies against platelet factor 4 (PF4), (ii) the direct interaction between adenoviral vector and platelets, (iii) the cross-reactivity of antibodies against SARS-CoV-2 spike protein with PF4, (iv) cross-reactivity of anti-adenovirus antibodies and PF4, (v) interaction between spike protein and platelets, (vi) the platelet expression of spike protein and subsequent immune response, and (vii) the platelet expression of other adenoviral proteins and subsequent reactions. It is also plausible that thrombotic thrombocytopenia after the COVID-19 vaccine is multifactorial. The elucidation of the causes of these adverse events is pivotal in taking precautionary measures and managing vaccine hesitancy. It needs to be stressed, however, that the reported cases are currently sporadic and that the benefits of COVID-19 vaccines vastly outweigh their potential risks.

scholarly journals Use of a Multidisciplinary Incident Command System in Response to Measles Outbreak in Maryland

2020 ◽  
Vol 41 (S1) ◽  
pp. s502-s504
Author(s):  
Taylor McIlquham ◽  
Anna Sick-Samuels ◽  
Carrie Billman ◽  
Jennifer Andonian ◽  
Melissa Dudley ◽  
...  
Keyword(s):  
The United States ◽  
Johns Hopkins Hospital ◽  
Occupational Health Services ◽  
Becton Dickinson ◽  
Distributed Resources ◽  
Incident Command System ◽  
Secondary Transmission ◽  
Incident Command ◽  
Measles Outbreak ◽  
Triage Algorithm

Background: Measles is a highly contagious virus that reemerged in 2019 with the highest number of reported cases in the United States since 1992. Beginning in March 2019, The Johns Hopkins Hospital (JHH) responded to an influx of patients with concern for measles as a result of outbreaks in Maryland and the surrounding states. We report the JHH Department of Infection Control and Hospital Epidemiology (HEIC) response to this measles outbreak using a multidisciplinary measles incident command system (ICS). Methods: The JHH HEIC and the Johns Hopkins Office of Emergency Management established the HEIC Clinical Incident Command Center and coordinated a multipronged response to the measles outbreak with partners from occupational health services, microbiology, the adult and pediatric emergency departments, marketing and communication and local and state public health departments. The multidisciplinary structure rapidly developed, approved, and disseminated tools to improve the ability of frontline providers to quickly identify, isolate, and determine testing needs for patients suspected to have measles infection and reduce the risk of secondary transmission. The tools included a triage algorithm, visitor signage, staff and patient vaccination guidance and clinics, and standard operating procedures for measles evaluation and testing. The triage algorithms were developed for phone or in-person and assessed measles exposure history, immune status, and symptoms, and provided guidance regarding isolation and the need for testing. The algorithms were distributed to frontline providers in clinics and emergency rooms across the Johns Hopkins Health System. The incident command team also distributed resources to community providers to reduce patient influx to JHH and staged an outdoor measles evaluation and testing site in the event of a case influx that would exceed emergency department resources. Results: From March 2019 through June 2019, 37 patients presented with symptoms or concern for measles. Using the ICS tools and algorithms, JHH rapidly identified, isolated, and tested 11 patients with high suspicion for measles, 4 of whom were confirmed positive. Of the other 26 patients not tested, none developed measles infection. Exposures were minimized, and there were no secondary measles transmissions among patients. Conclusions: Using the ICS and development of tools and resources to prevent measles transmission, including a patient triage algorithm, the JHH team successfully identified, isolated, and evaluated patients with high suspicion for measles while minimizing exposures and secondary transmission. These strategies may be useful to other institutions and locales in the event of an emerging or reemerging infectious disease outbreak.Funding: NoneDisclosures: Aaron Milstone reports consulting for Becton Dickinson.

scholarly journals Toward Resolving the Challenges of Sepsis Diagnosis

2004 ◽  
Vol 50 (8) ◽  
pp. 1301-1314 ◽  
Author(s):  
Shawn D Carrigan ◽  
George Scott ◽  
Maryam Tabrizian
Keyword(s):  
Medical Diagnosis ◽  
Delayed Diagnosis ◽  
High Sensitivity ◽  
The United States ◽  
Immune Monitoring ◽  
Diagnostic Methods ◽  
Magic Bullet ◽  
Sepsis Diagnosis ◽  
The Past ◽  
Related Mortality

Abstract Sepsis in the United States has an estimated annual healthcare cost of $16.7 billion and leads to 120 000 deaths. Insufficient development in both medical diagnosis and treatment of sepsis has led to continued growth in reported cases of sepsis over the past two decades with little improvement in mortality statistics. Efforts over the last decade to improve diagnosis have unsuccessfully sought to identify a “magic bullet” proteic biomarker that provides high sensitivity and specificity for infectious inflammation. More recently, genetic methods have made tracking regulation of the genes responsible for these biomarkers possible, giving current research new direction in the search to understand how host immune response combats infection. Despite the breadth of research, inadequate treatment as a result of delayed diagnosis continues to affect approximately one fourth of septic patients. In this report we review past and present diagnostic methods for sepsis and their respective limitations, and discuss the requirements for more timely diagnosis as the next step in curtailing sepsis-related mortality. We also present a proposal toward revision of the current diagnostic paradigm to include real-time immune monitoring.

scholarly journals Clinical Value of Multiplexed Bead-Based Immunoassays for Detection of Autoantibodies to Nuclear Antigens

2007 ◽  
Vol 14 (5) ◽  
pp. 505-509 ◽  
Author(s):  
Erik Avaniss-Aghajani ◽  
Sophia Berzon ◽  
Arlen Sarkissian
Keyword(s):  
Lupus Erythematosus ◽  
Fluorescent Antibody ◽  
False Positive Rate ◽  
High Sensitivity ◽  
Test System ◽  
Lower Percentage ◽  
Clinical Value ◽  
Specificity And Sensitivity ◽  
Relative Specificity ◽  
Positive Results

ABSTRACT The advent of multiplexed bead assays in recent years has introduced a new dimension of testing for complex diseases such as lupus, which can involve multiple autoantibodies. The ability to rapidly identify multiple autoantibodies, with high sensitivity and specificity in an automated fashion, is highly attractive. The aim of this study was to assess the performance and clinical value of multiplexed bead-based (AtheNA Multi-Lyte ANA-II test system) immunoassays both by comparing the results with those achieved by indirect fluorescent-antibody assay (IFA) or conventional enzyme immunoassays (EIAs) and by independent identification of autoantibodies in well-characterized samples. To achieve this goal, 984 samples were tested for seven analytes (SS/A, SS/B, Sm, RNP, Scl-70, double-stranded DNA [dsDNA], and centromere B) in both traditional and bead-based assays. The average concordance for the different analytes was 91%, ranging from 81% (dsDNA) to 97% (centromere B). The average relative specificity and sensitivity for the analytes were also high, 92% and 81%, respectively. An examination of 93 “normal controls” demonstrated a 7% false-positive rate, which was comparable to IFA. Percentages of different autoantibodies found in patients with a variety of disease conditions (34 with calcinosis, Raynaud's phenomenon, esophageal dysmotility, sclerodactyly, and telangiectasia; 41 with mixed connective tissue disease; 24 with scleroderma; and 35 with Sjogren's syndrome) were well within the range expected from each group. A scrutiny of results from AtheNA and EIA and Farr results for 185 systemic lupus erythematosus samples revealed comparable results by both methods, with the exception of SS/A and dsDNA, where AtheNA had a higher percentage of SS/A-positive results compared to EIA (51% versus 29%) and a lower percentage of dsDNA-positive results (18% versus 28% at a cutoff of 5 IU/ml).

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