Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 17 de 17
Filtrar
1.
J Intern Med ; 289(4): 559-573, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33034095

RESUMEN

BACKGROUND: Convalescent plasma therapy for COVID-19 relies on transfer of anti-viral antibody from donors to recipients via plasma transfusion. The relationship between clinical characteristics and antibody response to COVID-19 is not well defined. We investigated predictors of convalescent antibody production and quantified recipient antibody response in a convalescent plasma therapy clinical trial. METHODS: Multivariable analysis of clinical and serological parameters in 103 confirmed COVID-19 convalescent plasma donors 28 days or more following symptom resolution was performed. Mixed-effects regression models with piecewise linear trends were used to characterize serial antibody responses in 10 convalescent plasma recipients with severe COVID-19. RESULTS: Donor antibody titres ranged from 0 to 1 : 3892 (anti-receptor binding domain (RBD)) and 0 to 1 : 3289 (anti-spike). Higher anti-RBD and anti-spike titres were associated with increased age, hospitalization for COVID-19, fever and absence of myalgia (all P < 0.05). Fatigue was significantly associated with anti-RBD (P = 0.03). In pairwise comparison amongst ABO blood types, AB donors had higher anti-RBD and anti-spike than O donors (P < 0.05). No toxicity was associated with plasma transfusion. Non-ECMO recipient anti-RBD antibody titre increased on average 31% per day during the first three days post-transfusion (P = 0.01) and anti-spike antibody titre by 40.3% (P = 0.02). CONCLUSION: Advanced age, fever, absence of myalgia, fatigue, blood type and hospitalization were associated with higher convalescent antibody titre to COVID-19. Despite variability in donor titre, 80% of convalescent plasma recipients showed significant increase in antibody levels post-transfusion. A more complete understanding of the dose-response effect of plasma transfusion amongst COVID-19-infected patients is needed.


Asunto(s)
Anticuerpos Antivirales/sangre , Formación de Anticuerpos/inmunología , Prueba Serológica para COVID-19 , COVID-19/terapia , SARS-CoV-2 , Evaluación de Síntomas , Adulto , Anciano , Anticuerpos Neutralizantes/sangre , COVID-19/epidemiología , COVID-19/inmunología , COVID-19/fisiopatología , Prueba Serológica para COVID-19/métodos , Prueba Serológica para COVID-19/estadística & datos numéricos , Femenino , Humanos , Inmunización Pasiva/métodos , Inmunoglobulina G/sangre , Masculino , Persona de Mediana Edad , SARS-CoV-2/inmunología , SARS-CoV-2/aislamiento & purificación , Evaluación de Síntomas/métodos , Evaluación de Síntomas/estadística & datos numéricos , Resultado del Tratamiento , Estados Unidos , Sueroterapia para COVID-19
2.
J Clin Microbiol ; 52(12): 4334-8, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25232166

RESUMEN

This study describes an inexpensive and straightforward method for identifying bacteria by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) directly from positive blood cultures using prewarmed agar plates. Different inoculation methods and incubation times were evaluated to determine the optimal conditions. The two methods using pelleted material from positive culture bottles performed best. In particular, the pellet streak method correctly identified 94% of the Gram negatives following 4 h of incubation and 98% of the Gram positives following 6 h of incubation.


Asunto(s)
Bacteriemia/diagnóstico , Bacterias/aislamiento & purificación , Técnicas Bacteriológicas/métodos , Sangre/microbiología , Manejo de Especímenes/métodos , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos , Humanos , Sensibilidad y Especificidad , Temperatura , Factores de Tiempo
3.
J Clin Microbiol ; 52(9): 3433-6, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25031445

RESUMEN

The Verigene tests for Gram-positive and Gram-negative organisms in blood culture and the FilmArray blood culture identification panel were assessed for their ability to identify pathogens from positive blood cultures. Both platforms correctly identified bacteria in 92% of monomicrobial cultures analyzed, with times to identification that were significantly shorter than those for identification from subcultures.


Asunto(s)
Bacteriemia/diagnóstico , Bacteriemia/microbiología , Bacterias/aislamiento & purificación , Técnicas Microbiológicas/métodos , Técnicas de Diagnóstico Molecular/métodos , Bacterias/clasificación , Bacterias/genética , Humanos , Factores de Tiempo
4.
Clin Lab Med ; 19(3): 523-36, vi, 1999 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-10549424

RESUMEN

Yersinia enterocolitica can cause enteritis, right lower-quadrant pain mimicking appendicitis, reactive arthritis, and erythema nodosum. This organism is transmitted through food, animal contact, and contaminated blood products. Patients with iron excess are at a higher risk for serious infection. This article describes the history, microbiology, virulence factors, epidemiology, clinical manifestations, diagnosis, and therapy of Y. enterocolitica and Y. pseudotuberculosis. In addition, the immune response of those developing reactive arthritis following infection with Y. enterocolitica is discussed.


Asunto(s)
Microbiología de Alimentos , Yersinia enterocolitica/patogenicidad , Infecciones por Yersinia pseudotuberculosis , Yersinia pseudotuberculosis/patogenicidad , Animales , Australia/epidemiología , Europa (Continente)/epidemiología , Historia del Siglo XIX , Historia del Siglo XX , Humanos , América del Norte/epidemiología , Virulencia , Infecciones por Yersinia pseudotuberculosis/epidemiología , Infecciones por Yersinia pseudotuberculosis/historia , Infecciones por Yersinia pseudotuberculosis/patología , Infecciones por Yersinia pseudotuberculosis/terapia
5.
Cleve Clin J Med ; 58(4): 299-300, 1991.
Artículo en Inglés | MEDLINE | ID: mdl-1889111
13.
Semin Respir Infect ; 15(2): 132-43, 2000 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10983931

RESUMEN

This paper reviews the recent US history of infection with Mycobacterium tuberculosis and discusses the emergence of drug-resistant strains. The paper continues with brief discussions of the clinical presentation of tuberculosis, tuberculosis in the pediatric population, and nontuberculous pulmonary disease. We discuss laboratory techniques that will rapidly identify Mycobacterium tuberculosis and provide susceptibility test results. The advances and limitations of currently available diagnostic techniques are presented. The chapter concludes with an explanation of the current strengths and limitations of molecular diagnosis of disease and resistance.


Asunto(s)
Infecciones por Mycobacterium/diagnóstico , Mycobacterium/efectos de los fármacos , Mycobacterium/aislamiento & purificación , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Antituberculosos/farmacología , Antituberculosos/uso terapéutico , Técnicas de Laboratorio Clínico , Femenino , Humanos , Masculino , Pruebas de Sensibilidad Microbiana , Infecciones por Mycobacterium/tratamiento farmacológico , Sensibilidad y Especificidad , Tuberculosis Pulmonar/diagnóstico , Tuberculosis Pulmonar/tratamiento farmacológico
14.
J Clin Microbiol ; 34(11): 2778-83, 1996 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-8897182

RESUMEN

We evaluated the COBAS AMPLICOR (CA) PCR system (Roche Diagnostic Systems) designed for automated PCR amplification and detection of nucleic acids from infectious agents in clinical samples. The Roche AMPLICOR microwell plate (MWP) PCR was the reference method. CA amplifies target nucleic acid, captures the biotinylated amplification products by using magnetic particles coated with specific oligonucleotide probes, and detects the bound products colorimetrically. For Mycobacterium tuberculosis, the correlation of the results of CA tests with those of MWP tests was 100% with 230 samples, including 20 culture-positive samples. For hepatitis C virus, the correlation was 100% with 214 samples, including 60 positive samples. MultiPlex CA analysis of 199 cervical specimens for Chlamydia trachomatis, Neisseria gonorrhoeae, and the internal control gave 100% concordance. These samples included 19 C. trachomatis and 3 N. gonorrhoeae culture-positive samples. Overall, the agreement between PCR methods for all 842 comparisons was 100%. Compared with culture, the sensitivities of the assays for C. trachomatis and M tuberculosis were > or = 95%. After spiking alternating amplification tubes in the CA system with 10(14) copies of the Chlamydia amplicon per ml, we were unable to demonstrate any carryover cross-contamination of negative samples. Using the criteria of the College of American Pathologists workload recording method, we found that the total hands-on time to produce CA PCR results was 4.4, 7.9, and 3.3 min for M. tuberculosis, hepatis C virus, and the MultiPlexed assay for chlamydia plus gonorrhea and an internal control, respectively. The CA system brings true PCR automation to laboratories. In addition to the accuracy of automated results, the CA system provides labor savings, provides containment of the amplification and detection components of PCR, and supports both MultiPlex amplification and sequential algorithm (ReFlex) detection of analytes.


Asunto(s)
Técnicas Bacteriológicas/instrumentación , Reacción en Cadena de la Polimerasa/instrumentación , Virología/instrumentación , Automatización , Técnicas Bacteriológicas/estadística & datos numéricos , Chlamydia trachomatis/genética , Chlamydia trachomatis/aislamiento & purificación , Estudios de Evaluación como Asunto , Femenino , Hepacivirus/genética , Hepacivirus/aislamiento & purificación , Humanos , Laboratorios/organización & administración , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/aislamiento & purificación , Neisseria gonorrhoeae/genética , Neisseria gonorrhoeae/aislamiento & purificación , Reacción en Cadena de la Polimerasa/métodos , Reacción en Cadena de la Polimerasa/estadística & datos numéricos , Sensibilidad y Especificidad , Virología/métodos , Virología/estadística & datos numéricos
15.
J Clin Microbiol ; 35(8): 2068-71, 1997 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-9230383

RESUMEN

The BACTEC 460 system currently provides the most rapid detection of mycobacterial growth, but the system is radiometric and requires needles to inoculate specimens through the bottle's septum. The Mycobacteria Growth Indicator Tube (MGIT) system has a liquid medium, like the BACTEC system, and does not require needles when inoculating specimens. We compared mycobacterial growth from 510 specimens in the two systems. Average time to acid-fast bacillus (AFB) detection and identification to the species level was less with the BACTEC system, but this result was statistically significant only for AFB detection in specimens containing Mycobacterium avium-M. intracellulare complex. The contamination rate with MGIT was 29%; the BACTEC rate was 5%. To investigate MGIT contamination, we initiated a second study with changes in specimen processing. The MGIT contamination rate was reduced to 12%; the BACTEC rate was not significantly affected (5.5%). The most likely explanation for the contamination in MGIT is the richness of its medium compared to the BACTEC medium. Cost analysis for the two systems in a laboratory that processes 4,500 specimens a year is presented. The data suggest that the BACTEC 460 and the MGIT systems are approximately equivalent in cost and ability to support the growth of AFB. The MGIT system appears safer and easier to use and was preferred by laboratory personnel, but it cannot currently be used for blood specimens or antituberculosis susceptibility testing.


Asunto(s)
Técnicas Bacteriológicas , Mycobacterium/aislamiento & purificación , Bacterias/crecimiento & desarrollo , Contaminación de Equipos , Estudios de Evaluación como Asunto , Humanos , Mycobacterium/crecimiento & desarrollo
16.
Clin Infect Dis ; 30(2): 384-6, 2000 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-10671346

RESUMEN

Transjugular intrahepatic portosystemic shunt (TIPS) has become a routine procedure in patients with portal hypertension, yet there are few data concerning the incidence of bacteremia associated with this shunt. All patients who underwent TIPS placement at a university hospital from January 1992 through January 1999 were studied. Ninety-nine TIPS were placed, and 10 patients subsequently developed sustained bacteremia; 5 patients had no identifiable source of bacteremia despite rigorous evaluation and were presumed to represent TIPS infections, for an estimated annual incidence of 7 cases/1000 TIPS procedures. Case patients developed bacteremia a median of 100 days after TIPS placement (range, 6-732 days). Bacteremia resolved in all patients after treatment with appropriate intravenous antibiotics (median, 2 weeks of therapy). Although the incidence of TIPS-associated bacteremia appears low, the increasing frequency of this procedure suggests that more information is needed to define this entity and to develop appropriate treatment recommendations.


Asunto(s)
Bacteriemia/epidemiología , Bacteriemia/microbiología , Infecciones Bacterianas/epidemiología , Infecciones Bacterianas/microbiología , Derivación Portosistémica Intrahepática Transyugular/efectos adversos , Adulto , Anciano , Anciano de 80 o más Años , Antibacterianos/uso terapéutico , Bacteriemia/tratamiento farmacológico , Infecciones Bacterianas/tratamiento farmacológico , Femenino , Estudios de Seguimiento , Hospitales Universitarios/estadística & datos numéricos , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Philadelphia/epidemiología , Sistema de Registros , Factores de Riesgo , Resultado del Tratamiento
17.
J Clin Microbiol ; 33(10): 2582-6, 1995 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-8567886

RESUMEN

We evaluated the Amplicor PCR assay (Roche Molecular Systems, Branchburg, N.J.) for direct detection of Mycobacterium tuberculosis in sputum. A total of 532 specimens from 270 patients were decontaminated and stored at 4 or -75 degrees C until assayed by PCR. This assay used three-step sample preparation, biotinylated primer pairs, AmpErase, and a microtiter format for amplicon capture and detection. Amplicor PCR results were compared with clinical history, culture from a Lowenstein-Jensen slant, and results from the BACTEC TB-460 system. Eighty-seven cultures from 15 patients grew M. tuberculosis; of these, 83 (95%) were positive with the Amplicor PCR test. The false negatives were most likely due to sample variation and inhibitors. Of the 445 specimens from which M. tuberculosis was not isolated, 428 (96%) were negative with the Amplicor PCR test. Of the 17 M. tuberculosis culture-negative, Amplicor-positive specimens, 15 were reclassified as true positives because previous cultures grew M. tuberculosis. Of the 445 specimens which did not grow M. tuberculosis, Mycobacterium spp. other than M. tuberculosis were isolated from 150 specimens. Three of these 150 specimens were Amplicor positive; two were from a patient with a history of tuberculosis, and one specimen gave a false-positive result. We do not feel that this represents cross-reactivity, because repeated Amplicor testing of the isolate gave negative results. The microtiter plate has 96 wells. Allowing for six controls, 90 decontaminated specimens can be tested by one technologist in 7.5 h. This PCR assay took 7.5 h to complete and is a sensitive and specific, rapid method for the direct detection of M. tuberculosis from sputum.


Asunto(s)
ADN Bacteriano/aislamiento & purificación , Mycobacterium tuberculosis/aislamiento & purificación , Reacción en Cadena de la Polimerasa/métodos , Esputo/microbiología , Tuberculosis/diagnóstico , Manejo de Caso , ADN Ribosómico/aislamiento & purificación , Estudios de Evaluación como Asunto , Humanos , Mycobacterium tuberculosis/citología , Mycobacterium tuberculosis/genética , ARN Ribosómico 16S/genética , Juego de Reactivos para Diagnóstico , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Manejo de Especímenes , Coloración y Etiquetado , Factores de Tiempo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA