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1.
J Clin Microbiol ; 58(9)2020 08 24.
Artículo en Inglés | MEDLINE | ID: mdl-32641399

RESUMEN

Blood culture (BC) often fails to detect bloodstream microorganisms in sepsis. However, molecular diagnostics hold great potential. The molecular method PCR/electrospray ionization-mass spectrometry (PCR/ESI-MS) can detect DNA from hundreds of different microorganisms in whole blood. The aim of the present study was to evaluate the performance of this method in a multicenter study including 16 teaching hospitals in the United States (n = 13) and Europe (n = 3). First, on testing of 2,754 contrived whole blood samples, with or without spiked microorganisms, PCR/ESI-MS produced 99.1% true-positive and 97.2% true-negative results. Second, among 1,460 patients with suspected sepsis (sepsis-2 definition), BC and PCR/ESI-MS on whole blood were positive in 14.6% and 25.6% of cases, respectively, with the following result combinations: BC positive and PCR/ESI-MS negative, 4.3%; BC positive and PCR/ESI-MS positive, 10.3%; BC negative and PCR/ESI-MS positive, 15.3%; and BC negative and PCR/ESI-MS negative, 70.1%. Compared with BC, PCR/ESI-MS showed the following sensitivities (coagulase-negative staphylococci not included): Gram-positive bacteria, 58%; Gram-negative bacteria, 78%; and Candida species, 83%. The specificities were >94% for all individual species. Patients who had received prior antimicrobial medications (n = 603) had significantly higher PCR/ESI-MS positivity rates than patients without prior antimicrobial treatment-31% versus 22% (P < 0.0001)-with pronounced differences for Gram-negative bacteria and Candida species. In conclusion, PCR/ESI-MS showed excellent performance on contrived samples. On clinical samples, it showed high specificities, moderately high sensitivities for Gram-negative bacteria and Candida species, and elevated positivity rates during antimicrobial treatment. These promising results encourage further development of molecular diagnostics to be used with whole blood for detection of bloodstream microorganisms in sepsis.


Asunto(s)
Sepsis , Espectrometría de Masa por Ionización de Electrospray , Cultivo de Sangre , Europa (Continente) , Humanos , Reacción en Cadena de la Polimerasa , Sepsis/diagnóstico
2.
J Clin Microbiol ; 56(4)2018 04.
Artículo en Inglés | MEDLINE | ID: mdl-29305546

RESUMEN

We describe results from a multicenter study evaluating the Accelerate Pheno system, a first of its kind diagnostic system that rapidly identifies common bloodstream pathogens from positive blood cultures within 90 min and determines bacterial phenotypic antimicrobial susceptibility testing (AST) results within ∼7 h. A combination of fresh clinical and seeded blood cultures were tested, and results from the Accelerate Pheno system were compared to Vitek 2 results for identification (ID) and broth microdilution or disk diffusion for AST. The Accelerate Pheno system accurately identified 14 common bacterial pathogens and two Candida spp. with sensitivities ranging from 94.6 to 100%. Of fresh positive blood cultures, 89% received a monomicrobial call with a positive predictive value of 97.3%. Six common Gram-positive cocci were evaluated for ID. Five were tested against eight antibiotics, two resistance phenotypes (methicillin-resistant Staphylococcus aureus and Staphylococcus spp. [MRSA/MRS]), and inducible clindamycin resistance (MLSb). From the 4,142 AST results, the overall essential agreement (EA) and categorical agreement (CA) were 97.6% and 97.9%, respectively. Overall very major error (VME), major error (ME), and minor error (mE) rates were 1.0%, 0.7%, and 1.3%, respectively. Eight species of Gram-negative rods were evaluated against 15 antibiotics. From the 6,331 AST results, overall EA and CA were 95.4% and 94.3%, respectively. Overall VME, ME, and mE rates were 0.5%, 0.9%, and 4.8%, respectively. The Accelerate Pheno system has the unique ability to identify and provide phenotypic MIC and categorical AST results in a few hours directly from positive blood culture bottles and support accurate antimicrobial adjustment.


Asunto(s)
Cultivo de Sangre/métodos , Pruebas de Sensibilidad Microbiana/métodos , Fenotipo , Juego de Reactivos para Diagnóstico/estadística & datos numéricos , Antibacterianos/farmacología , Cultivo de Sangre/instrumentación , Pruebas Antimicrobianas de Difusión por Disco/métodos , Bacterias Gramnegativas/efectos de los fármacos , Infecciones por Bacterias Gramnegativas/sangre , Infecciones por Bacterias Gramnegativas/diagnóstico , Infecciones por Bacterias Gramnegativas/microbiología , Bacterias Grampositivas/efectos de los fármacos , Infecciones por Bacterias Grampositivas/sangre , Infecciones por Bacterias Grampositivas/diagnóstico , Infecciones por Bacterias Grampositivas/microbiología , Humanos , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción
3.
Proc (Bayl Univ Med Cent) ; 30(4): 395-399, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28966443

RESUMEN

We performed a retrospective chart review of patients to determine if the Verigene Gram-negative blood culture (BC-GN) results would lead to earlier deescalation of empiric therapy for inpatients with GN bacteremia with Citrobacter spp., Enterobacter spp., Klebsiella spp., and Escherichia coli to appropriate targeted coverage. A total of 899 records were reviewed from April 2014 to February 2016 from three institutions within the Baylor Scott & White Health network. The cases were reviewed for initial antibiotic coverage, timing of Verigene results, change in antibiotic coverage, and how these changes related to the timing of Verigene results. The lab reported the BC-GN results and final conventional susceptibility results within 2.5 ± 1.3 and 73.6 ± 40.0 hours from the Gram stain, respectively. Overall, 29.1% of patients were transitioned from empiric to targeted therapy at 12.2 ± 13.5 hours in response to BC-GN results, which was significantly earlier (P < 0.001) than results by conventional methods. After accounting for patients already on targeted therapy, polymicrobial infections, and patients deceased or lost to follow-up, we identified antibiotic stewardship opportunities in ∼28% of GN infections. Further subanalysis demonstrated site-specific differences in the uptake of stewardship recommendations, whereby 32.4%, 50.5%, and 15.0% of cases at different hospitals demonstrated the expected change in antibiotics. These results suggest that Verigene had the expected impact in a third of the cases and the results reporting algorithm minimized the real-time involvement of the pharmacist while maintaining optimal patient management. However, this impact varied substantially by clinical site and was tempered by variable initial antibiotic coverage and clinician response.

4.
Proc (Bayl Univ Med Cent) ; 28(3): 342-3, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-26130883

RESUMEN

Myroides species are a rare source of human infection. Though not part of the human microbiota, Myroides species are commonly found in the environment. Myroides infections are typically attributed to contact with contaminated water; the most common presentation is in immunocompromised patients. We present a patient with a diabetic foot ulcer who subsequently developed Myroides odoratimimus bacteremia and bone abscess.

5.
J Clin Microbiol ; 53(8): 2460-72, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25994165

RESUMEN

Bloodstream infection is a serious condition associated with significant morbidity and mortality. The outcome of these infections can be positively affected by the early implementation of effective antibiotic therapy based on the identification of the infecting organism and genetic markers associated with antibiotic resistance. In this study, we evaluated the microarray-based Verigene Gram-negative blood culture (BC-GN) assay in the identification of 8 genus or species targets and 6 genetic resistance determinants in positive blood culture broths. A total of 1,847 blood cultures containing Gram-negative organisms were tested using the BC-GN assay. This comprised 729 prospective fresh, 781 prospective or retrospective frozen, and 337 simulated cultures representing 7 types of aerobic culture media. The results were compared to those with standard bacterial culture and biochemical identification with nucleic acid sequence confirmation of the resistance determinants. Among monomicrobial cultures, the positive percent agreement (PPA) of the BC-GN assay with the reference method was as follows; Escherichia coli, 100%; Klebsiella pneumoniae, 92.9%; Klebsiella oxytoca, 95.5%; Enterobacter spp., 99.3%; Pseudomonas aeruginosa, 98.9%; Proteus spp., 100%; Acinetobacter spp., 98.4%; and Citrobacter spp., 100%. All organism identification targets demonstrated >99.5% negative percent agreement (NPA) with the reference method. Of note, 25/26 cultures containing K. pneumoniae that were reported as not detected by the BC-GN assay were subsequently identified as Klebsiella variicola. The PPA for identification of resistance determinants was as follows; blaCTX-M, 98.9%; blaKPC, 100%; blaNDM, 96.2%; blaOXA, 94.3%; blaVIM, 100%; and blaIMP, 100%. All resistance determinant targets demonstrated >99.9% NPA. Among polymicrobial specimens, the BC-GN assay correctly identified at least one organism in 95.4% of the broths and correctly identified all organisms present in 54.5% of the broths. The sample-to-result processing and automated reading of the detection microarray results enables results within 2 h of culture positivity.


Asunto(s)
Bacteriemia/diagnóstico , Farmacorresistencia Bacteriana , Bacterias Gramnegativas/genética , Bacterias Gramnegativas/aislamiento & purificación , Infecciones por Bacterias Gramnegativas/diagnóstico , Técnicas de Diagnóstico Molecular/métodos , Bacteriemia/microbiología , Técnicas Bacteriológicas/métodos , Infecciones por Bacterias Gramnegativas/microbiología , Humanos , Análisis por Micromatrices/métodos , Estudios Prospectivos , Estudios Retrospectivos , Factores de Tiempo
6.
Proc (Bayl Univ Med Cent) ; 28(2): 139-43, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25829639

RESUMEN

New technologies offer rapid identification of organisms and antimicrobial resistance markers in blood cultures several hours faster than conventional methods. We sought to determine whether implementation of the Verigene® Gram-Positive Blood Culture (BC-GP) assay paired with a well-defined results reporting algorithm would lead to earlier deescalation of empiric therapy for inpatients with methicillin-sensitive Staphylococcus aureus (MSSA) and vancomycin-resistant Enterococcus (VRE) bacteremia. The algorithm design focused on lessening the demand for pharmacist time by using electronic communications where possible. Our study compared inpatients with MSSA and VRE bacteremia from the time period before (pre-BC-GP) and after (post-BC-GP) implementation of the assay on June 25, 2013. The time from blood draw to identification and susceptibility results was decreased by 36.4 hours (P < 0.001) in the post-BC-GP group. The mean time from collection to the first dose of optimal antibiotics was reduced in the post-BC-GP group by 18.9 hours (P = 0.004) overall, with a 20.6-hour reduction (P = 0.009) for patients with MSSA and a 20.7-hour reduction (P = 0.077) for patients with VRE. Additionally, the percent of patients on empiric therapy who were placed on optimal antibiotics at any time after the Gram stain result was available increased from 64% (45/70) pre-BC-GP to 80% (43/54) post-BC-GP. The BC-GP led to an increased rate of deescalation of empiric antibiotics and a reduction in the time to optimal antibiotics for patients with MSSA and VRE bacteremia.

7.
Proc (Bayl Univ Med Cent) ; 28(2): 144-50, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25829640

RESUMEN

Successful performance and execution of rapid diagnostics in a clinical laboratory hinges heavily on careful validation, accurate and timely communication of results, and real-time quality monitoring. Laboratories must develop strategies to integrate diagnostics with stewardship and evidence-based clinical practice guidelines. We present a collaborative SUCCESS model for execution and monitoring of rapid sepsis diagnostics to facilitate timely treatment. Six months after execution of the Verigene Gram-Positive Blood Culture (BC-GP) and the AdvanDx PNA-FISH assays, data were collected on 579 and 28 episodes of bacteremia and fungemia, respectively. Clinical testing was executed using a SUCCESS model comprising the following components: stewardship, utilization of resources, core strategies, concierge services, education, support, and surveillance. Stewardship needs were identified by evaluating the specialty services benefiting from new testing. Utilization of resources was optimized by reviewing current treatment strategies and antibiogram and formulary options. Core strategies consisted of input from infectious disease leadership, pharmacy, and laboratory staff. Concierge services included automated Micro-eUpdate and physician-friendly actionable reports. Education modules were user-specific, and support was provided through a dedicated 24/7 microbiology hotline. Surveillance was performed by daily audit by the director. Using the SUCCESS model, the turnaround time for the detailed report with actionable guidelines to the physician was ∼3 hours from the time of culture positivity. The overall correlation between rapid methods and culture was 94% (546/579). Discrepant results were predominantly contaminants such as a coagulase-negative staphylococci or viridans streptococci in mixed cultures. SUCCESS is a cost-effective and easily adaptable model for clinical laboratories with limited stewardship resources.

8.
J Clin Microbiol ; 51(9): 2939-42, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23804393

RESUMEN

The ability of the rapid BinaxNOW Staphylococcus aureus (BNSA) immunochromatographic test (Alere Scarborough, Inc., ME) to accurately differentiate S. aureus from coagulase-negative staphylococci (CoNS) and other Gram-positive cocci (GPC) directly from VersaTREK blood culture bottles was evaluated. A total of 319 positive patient blood culture bottles with GPC seen in clusters with Gram staining were tested using the BNSA test and a direct tube coagulase test (DTCT). The BNSA test was accurate for the detection and differentiation of S. aureus from CoNS and other GPC within 30 min from the time of blood culture positivity and demonstrated a test sensitivity and specificity of 95.8% and 99.6%, respectively. BNSA test results were faxed to the antimicrobial stewardship pharmacist by noon each day in order to evaluate empirical antimicrobial therapy and facilitate more rapid changes or modifications if necessary. Same-day reporting of BNSA test results in conjunction with an antimicrobial stewardship program was more impactful in improving treatment for inpatients with documented S. aureus bacteremia than in reducing empirical vancomycin use in inpatients with CoNS during the first 24 h following reporting.


Asunto(s)
Bacteriemia/diagnóstico , Técnicas Bacteriológicas/métodos , Sangre/microbiología , Cromatografía de Afinidad/métodos , Infecciones Estafilocócicas/diagnóstico , Staphylococcus aureus/aislamiento & purificación , Bacteriemia/microbiología , Humanos , Sensibilidad y Especificidad , Infecciones Estafilocócicas/microbiología , Staphylococcus aureus/clasificación , Factores de Tiempo
9.
J Infect Dis ; 206(10): 1512-20, 2012 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-22949304

RESUMEN

BACKGROUND: The mechanisms underlying smallpox vaccine-induced variations in immune responses are not well understood, but are of considerable interest to a deeper understanding of poxvirus immunity and correlates of protection. METHODS: We assessed transcriptional messenger RNA expression changes in 197 recipients of primary smallpox vaccination representing the extremes of humoral and cellular immune responses. RESULTS: The 20 most significant differentially expressed genes include a tumor necrosis factor-receptor superfamily member, an interferon (IFN) gene, a chemokine gene, zinc finger protein genes, nuclear factors, and histones (P ≤ 1.06E(-20), q ≤ 2.64E(-17)). A pathway analysis identified 4 enriched pathways with cytokine production by the T-helper 17 subset of CD4+ T cells being the most significant pathway (P = 3.42E(-05)). Two pathways (antiviral actions of IFNs, P = 8.95E(-05); and IFN-α/ß signaling pathway, P = 2.92E(-04)), integral to innate immunity, were enriched when comparing high with low antibody responders (false discovery rate, < 0.05). Genes related to immune function and transcription (TLR8, P = .0002; DAPP1, P = .0003; LAMP3, P = 9.96E(-05); NR4A2, P ≤ .0002; EGR3, P = 4.52E(-05)), and other genes with a possible impact on immunity (LNPEP, P = 3.72E(-05); CAPRIN1, P = .0001; XRN1, P = .0001), were found to be expressed differentially in high versus low antibody responders. CONCLUSION: We identified novel and known immunity-related genes and pathways that may account for differences in immune response to smallpox vaccination.


Asunto(s)
Anticuerpos Antivirales/biosíntesis , Citocinas/metabolismo , Regulación de la Expresión Génica/inmunología , ARN Mensajero/metabolismo , Vacuna contra Viruela/inmunología , Transcriptoma , Adulto , Anticuerpos Neutralizantes/biosíntesis , Anticuerpos Neutralizantes/sangre , Anticuerpos Antivirales/sangre , Citocinas/genética , Ensayo de Immunospot Ligado a Enzimas , Femenino , Humanos , Leucocitos Mononucleares/virología , Masculino , Análisis por Matrices de Proteínas , ARN Mensajero/genética , Viruela/prevención & control , Adulto Joven
10.
Mayo Clin Proc ; 87(6): 548-54, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22551906

RESUMEN

OBJECTIVE: To compare the effectiveness of self-collected and health care worker (HCW)-collected nasal swabs for detection of influenza viruses and determine the patients' preference for type of collection. PATIENTS AND METHODS: We enrolled adult patients presenting with influenzalike illness to the Emergency Department at Mayo Clinic, Rochester, Minnesota, from January 28, 2011, through April 30, 2011. Patients self-collected a midturbinate nasal flocked swab from their right nostril following written instructions. A second swab was then collected by an HCW from the left nostril. Swabs were tested for influenza A and B viruses by real-time reverse transcription-polymerase chain reaction, and percent concordance between collection methods was determined. RESULTS: Of the 72 paired specimens analyzed, 25 were positive for influenza A or B RNA by at least one of the collection methods (34.7% positivity rate). When the 14 patients who had prior health care training were excluded, the qualitative agreement between collection methods was 94.8% (55 of 58). Two of the 58 specimens (3.4%) from patients without health care training were positive only by HCW collection, and 1 of 58 (1.7%) was positive only by patient self-collection. A total of 53.4% of patients (31 of 58) preferred the self-collection method over the HCW collection, and 25.9% (15 of 58) had no preference. CONCLUSION: Self-collected midturbinate nasal swabs provide a reliable alternative to HCW collection for influenza A and B virus real-time reverse transcription-polymerase chain reaction.


Asunto(s)
Líquidos Corporales/virología , Mucosa Nasal/virología , Manejo de Especímenes/métodos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Satisfacción del Paciente , Reacción en Cadena en Tiempo Real de la Polimerasa , Adulto Joven
11.
J Infect Dis ; 204(3): 433-41, 2011 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-21742843

RESUMEN

BACKGROUND: Identifying genetic factors that influence poxvirus immunity across races may assist in the development of better vaccines and approaches for vaccine development. METHODS: We performed an extensive candidate-gene genetic screen (across 32 cytokine and cytokine receptor genes) in a racially diverse cohort of 1056 healthy adults after a single dose of smallpox vaccine. Associations between single-nucleotide polymorphisms (SNPs)/haplotypes and vaccinia virus-specific neutralizing antibodies were assessed using linear regression methodologies. RESULTS: The combined analysis identified 63 associations between candidate SNPs and antibody levels after smallpox vaccination with P < .05. Thirty-one of these were within the IL18R1 and IL18 genes. Five IL18R1 SNPs, including a coding synonymous polymorphism rs1035130 (Phe251Phe) and 2 promoter SNPs (rs6710885, rs2287037), all in linkage disequilibrium, were associated with significant variations in antibody levels in both Caucasians (P ≤ .016) and African Americans (P ≤ .025). Similarly, associations with 2 intronic IL18 SNPs (rs2043055 and rs5744280) were consistent in the Caucasian (P ≤ .023) and African American samples (P ≤ .014). Haplotype analysis revealed highly significant associations between IL18R1 haplotypes and vaccinia virus-specific antibody levels (P < .001, by combined analysis) that were consistent across races. CONCLUSIONS: Our study provides evidence for IL18 and IL18R1 genes as plausible genes regulating the humoral immune response to smallpox vaccine in both Caucasians and African Americans.


Asunto(s)
Anticuerpos Antivirales/sangre , Haplotipos , Inmunidad Humoral , Subunidad alfa del Receptor de Interleucina-18/genética , Interleucina-18/genética , Polimorfismo de Nucleótido Simple , Vacuna contra Viruela/inmunología , Adolescente , Adulto , Negro o Afroamericano , Femenino , Humanos , Modelos Lineales , Masculino , Vacunación , Población Blanca
12.
J Med Microbiol ; 60(Pt 12): 1869-1871, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21799200

RESUMEN

Trichoderma longibrachiatum is an emerging pathogen in immunocompromised patients. We report a case of Trichoderma post-operative mediastinitis and peritonitis in a child with complex congenital cardiac disease and functional asplenia. The patient was treated unsuccessfully, initially with caspofungin alone followed by a combination of voriconazole (systemic and topical), caspofungin and intraperitoneal amphotericin B.


Asunto(s)
Cardiopatías Congénitas/cirugía , Mediastinitis , Micosis , Peritonitis , Complicaciones Posoperatorias , Trichoderma , Anfotericina B/uso terapéutico , Antifúngicos/uso terapéutico , Caspofungina , Preescolar , Equinocandinas/uso terapéutico , Resultado Fatal , Femenino , Cardiopatías Congénitas/complicaciones , Humanos , Huésped Inmunocomprometido , Lipopéptidos , Mediastinitis/complicaciones , Mediastinitis/tratamiento farmacológico , Mediastinitis/microbiología , Micosis/tratamiento farmacológico , Diálisis Peritoneal , Peritonitis/complicaciones , Peritonitis/tratamiento farmacológico , Peritonitis/microbiología , Pirimidinas/uso terapéutico , Bazo/anomalías , Triazoles/uso terapéutico , Voriconazol
13.
Diagn Microbiol Infect Dis ; 70(4): 538-40, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21658875

RESUMEN

Herpes simplex virus (HSV) and varicella-zoster virus (VZV) may cause latent infection of the same peripheral nerve ganglia. However, there are no large studies addressing the frequency of concurrent HSV/VZV PCR positivity from the same anatomic location. In an eight-year retrospective study, we observed 1.3% dual positivity from dermal, genital, and oral mucosal sources.


Asunto(s)
Técnicas de Laboratorio Clínico/métodos , Herpes Simple/epidemiología , Herpes Zóster/epidemiología , Herpesvirus Humano 3/aislamiento & purificación , Reacción en Cadena de la Polimerasa/métodos , Simplexvirus/aislamiento & purificación , Virología/métodos , Adulto , Anciano , Comorbilidad , Femenino , Herpesvirus Humano 3/genética , Humanos , Masculino , Persona de Mediana Edad , Prevalencia , Estudios Retrospectivos , Simplexvirus/genética
14.
BMC Bioinformatics ; 12: 129, 2011 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-21535878

RESUMEN

BACKGROUND: Linkage Disequilibrium (LD) bin-tagging algorithms identify a reduced set of tag SNPs that can capture the genetic variation in a population without genotyping every single SNP. However, existing tag SNP selection algorithms for designing custom genotyping panels do not take into account all platform dependent factors affecting the likelihood of a tag SNP to be successfully genotyped and many of the constraints that can be imposed by the user. RESULTS: SNPPicker optimizes the selection of tag SNPs from common bin-tagging programs to design custom genotyping panels. The application uses a multi-step search strategy in combination with a statistical model to maximize the genotyping success of the selected tag SNPs. User preference toward functional SNPs can also be taken into account as secondary criteria. SNPPicker can also optimize tag SNP selection for a panel tagging multiple populations. SNPPicker can optimize custom genotyping panels including all the assay-specific constraints of Illumina's GoldenGate and Infinium assays. CONCLUSIONS: A new application has been developed to maximize the success of custom multi-population genotyping panels. SNPPicker also takes into account user constraints including options for controlling runtime. Perl Scripts, Java source code and executables are available under an open source license for download at http://mayoresearch.mayo.edu/mayo/research/biostat/software.cfm.


Asunto(s)
Algoritmos , Polimorfismo de Nucleótido Simple , Genética de Población , Genotipo , Humanos , Desequilibrio de Ligamiento , Modelos Estadísticos , Virus/inmunología
15.
J Immunol Methods ; 366(1-2): 69-78, 2011 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-21277306

RESUMEN

INTRODUCTION: We sought to determine the time and vaccinia virus dose combination that would maximize the number of acute immune response changes in response to vaccinia stimulation in preparation for a large gene expression microarray experiment. METHODS: PBMCs from ten subjects were exposed to five vaccinia virus doses for three lengths of time. Gene expression was measured for 90 immune response genes via Taqman® Low Density Immune Arrays. Expression data were normalized via model-based non-linear normalization. Linear mixed effects model results were used to standardize changes across genes and determine the time/multiplicity of infection (MOI) combination with the largest number of changes. RESULTS: The greatest number of changes occurred with a MOI of 5.0 and exposure time of 48 h. Further inspection revealed that most changes had occurred earlier and faded at this combination. The second highest number of changes was found at a MOI of 0.5 PFU/cell and time of 18 h. CONCLUSIONS: We conclude a time of 18 h with a MOI of 0.5 PFU/cell is the optimal time/MOI combination for the full scale gene expression study. The strategy described herein is a general and resource efficient way to make critical decisions regarding experimental parameters for studies utilizing expensive assays that interrogate a large number of variables.


Asunto(s)
Perfilación de la Expresión Génica/métodos , Genes MHC Clase II , Análisis de Secuencia por Matrices de Oligonucleótidos/métodos , Reacción en Cadena de la Polimerasa/métodos , Vacuna contra Viruela/administración & dosificación , Adolescente , Adulto , Anticuerpos Neutralizantes/sangre , Anticuerpos Antivirales/sangre , Citocinas/biosíntesis , Relación Dosis-Respuesta Inmunológica , Humanos , Técnicas In Vitro , Leucocitos Mononucleares/inmunología , Leucocitos Mononucleares/virología , Vacuna contra Viruela/inmunología , Virus Vaccinia/inmunología , Adulto Joven
16.
J Clin Microbiol ; 49(4): 1614-6, 2011 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21270234

RESUMEN

Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry was compared to phenotypic testing for yeast identification. MALDI-TOF mass spectrometry yielded 96.3% and 84.5% accurate species level identifications (spectral scores, ≥ 1.8) for 138 common and 103 archived strains of yeast. MALDI-TOF mass spectrometry is accurate, rapid (5.1 min of hands-on time/identification), and cost-effective ($0.50/sample) for yeast identification in the clinical laboratory.


Asunto(s)
Técnicas de Laboratorio Clínico/métodos , Micología/métodos , Micosis/diagnóstico , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos , Levaduras/aislamiento & purificación , Técnicas de Laboratorio Clínico/economía , Costos y Análisis de Costo , Humanos , Micología/economía , Micosis/microbiología , Sensibilidad y Especificidad , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/economía , Factores de Tiempo , Levaduras/química , Levaduras/clasificación
17.
J Med Virol ; 82(11): 1966-75, 2010 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-20872725

RESUMEN

The measles virus phosphoprotein (P) gene encodes the P, V, and C proteins, which have multiple functions including type I interferon (IFN) inhibition. With a focus on viral immune modulation, we conducted a study on healthy vaccinees (n=179) to compare cytokine secretion patterns/cell frequencies and gene expression after in vitro encounter with a highly attenuated strain of measles virus (MVEdmtag), wild-type MV (MVwt) or recombinant MVEdmtag expressing the wild-type P gene (MVwtP). Cytokines were quantified by ELISA and Elispot. Gene expression profiling was performed using real-time PCR. We found differential MV-specific cytokine responses to all detected cytokines characterized by significantly higher cytokine levels (P<0.001) and higher frequencies (P<0.0001) of cytokine-producing cells after stimulation with the highly attenuated MVEdmtag strain in comparison with MVwt or MVwtP. Furthermore, gene expression profiling revealed significant cytokine suppression at the transcriptional level for viruses encoding the functional wt P gene, compared to attenuated MVEdmtag (P<0.05). Using lentivirus-mediated stable expression of P gene-encoded proteins in human cell lines, we demonstrated that the expression of the functional wt V protein significantly down-modulated the induction of IFNs type I, II, and III in lymphocytes and monocytes. Taken together our results indicate that Th1, Th2, and innate/inflammatory cytokine responses in vaccinees are suppressed both at the protein and transcriptional level by viruses expressing the functional wt P gene products. The functional P gene-encoded viral proteins (particularly V proteins) emerge as crucial immune evasion factors for modulating and shaping the measles virus-specific cytokine responses in humans.


Asunto(s)
Citocinas/metabolismo , Vacuna Antisarampión/inmunología , Virus del Sarampión/inmunología , Fosfoproteínas/inmunología , Linfocitos T/inmunología , Vacunas Atenuadas/inmunología , Proteínas Virales/inmunología , Adolescente , Línea Celular , Citocinas/genética , Perfilación de la Expresión Génica , Humanos , Evasión Inmune , Inmunidad Celular , Activación de Linfocitos , Sarampión/inmunología , Sarampión/virología , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , Proteínas Virales/genética , Proteínas Virales/metabolismo
19.
Diagn Microbiol Infect Dis ; 67(4): 346-9, 2010 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-20638602

RESUMEN

Serologic testing for measles, mumps, rubella, and varicella (MMRV) IgG is traditionally performed by immunofluorescence assay or enzyme immunoassay (EIA). Although sensitive and specific, these methods are labor intensive, time consuming, and require separate assays for each analyte. This study evaluated the performance of the MMRV IgG AtheNA Multi-Lyte assay using nonclinically characterized serum specimens submitted to our laboratory for routine MMRV IgG testing. Mumps (n = 492) or rubella (n = 500) IgG were initially tested by enzyme-linked fluorescent antibody (ELFA), whereas measles (n = 494) or varicella (n = 497) were analyzed by EIA. Each sample was also tested by the AtheNA Multi-Lyte assay. Discordant results were retested by the predicate method and the multiplex assay, with further discrepancies being arbitrated by a third test. Compared to EIA/ELFA for MMRV IgG, the AtheNA assay demonstrated an overall agreement of 97.4%, 98.2%, 97.6%, and 100%, respectively. Use of this multiplex assay allows for the simultaneous detection of MMRV IgG, potentially decreasing cost, sample volume requirements, aliquot errors, and hands-on testing time.


Asunto(s)
Anticuerpos/sangre , Herpes Zóster/diagnóstico , Inmunoglobulina G/sangre , Sarampión/diagnóstico , Paperas/diagnóstico , Rubéola (Sarampión Alemán)/diagnóstico , Virología/métodos , Herpesvirus Humano 3/inmunología , Humanos , Inmunoensayo/métodos , Virus del Sarampión/inmunología , Microesferas , Virus de la Parotiditis/inmunología , Juego de Reactivos para Diagnóstico , Virus de la Rubéola/inmunología
20.
Immunogenetics ; 62(4): 197-210, 2010 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-20217072

RESUMEN

An effective immune response to vaccination is, in part, a complex interaction of alleles of multiple genes regulating cytokine networks. We conducted a genotyping study of Th1/Th2/inflammatory cytokines/cytokine receptors in healthy children (n = 738, 11-19 years) to determine associations between individual single-nucleotide polymorphisms (SNPs)/haplotypes and immune outcomes after two doses of rubella vaccine. SNPs (n = 501) were selected using the ldSelect-approach and genotyped using Illumina GoldenGate and TaqMan assays. Rubella-IgG levels were measured by immunoassay and secreted cytokines by ELISA. Linear regression and post hoc haplotype analyses were used to determine associations between single SNPs/haplotypes and immune outcomes. Increased carriage of minor alleles for the promoter SNPs (rs2844482 and rs2857708) of the TNFA gene were associated with dose-related increases in rubella antibodies. IL-6 secretion was co-directionally associated (p < or = 0.01) with five intronic SNPs in the TNFRSF1B gene in an allele dose-related manner, while five promoter/intronic SNPs in the IL12B gene were associated with variations in IL-6 secretion. TNFA haplotype AAACGGGGC (t-statistic = 3.32) and IL12B promoter haplotype TAG (t-statistic = 2.66) were associated with higher levels of (p < or = 0.01) rubella-IgG and IL-6 secretion, respectively. We identified individual SNPs/haplotypes in TNFA/TNFRSF1B and IL12B genes that appear to modulate immunity to rubella vaccination. Identification of such "genetic fingerprints" may predict the outcome of vaccine response and inform new vaccine strategies.


Asunto(s)
Citocinas/genética , Haplotipos , Polimorfismo de Nucleótido Simple/genética , Receptores de Citocinas/genética , Vacuna contra la Rubéola/inmunología , Rubéola (Sarampión Alemán)/inmunología , Adolescente , Adulto , Anticuerpos Antivirales/sangre , Niño , Femenino , Humanos , Inmunidad Celular , Inmunoglobulina G/sangre , Interleucina-6/genética , Interleucina-6/inmunología , Masculino , Regiones Promotoras Genéticas , Rubéola (Sarampión Alemán)/genética , Factor de Necrosis Tumoral alfa/genética , Factor de Necrosis Tumoral alfa/inmunología , Vacunación , Adulto Joven
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