RESUMEN
Over the period 1995-2012, the incidence of invasive meningococcal disease (IMD) caused by Neisseria meningitidis serogroup Y (NmY) increased significantly in Sweden. This is mainly due to the emergence of a predominant cluster named strain type YI subtype 1, belonging to the ST-23 clonal complex (cc). The aim of this study was to examine the clinical picture of patients with invasive disease caused by NmY and to analyse whether the predominant cluster exhibits certain clinical characteristics that might explain the increased incidence. In this retrospective observational study, the medical records available from patients with IMD caused by Nm serogroup Y in Sweden between 1995 and 2012 were systematically reviewed. Patient characteristics, in-hospital findings and outcome were studied and differences between the dominating cluster and other isolates were analysed. Medical records from 175 of 191 patients were retrieved. The median age was 62 years. The all-cause mortality within 30 days of admission was 9% (15/175) in the whole material; 4% (2/54) in the cohort with strain type YI subtype 1 and 11% (12/121) among patients with other isolates. Thirty-three per cent of the patients were diagnosed with meningitis, 19% with pneumonia, 10% with arthritis and 35% were found to have bacteraemia but no apparent organ manifestation. This survey included cases with an aggressive clinical course as well as cases with a relatively mild clinical presentation. There was a trend towards lower mortality and less-severe disease in the cohort with strain type YI subtype 1 compared with the group with other isolates.
Asunto(s)
Infecciones Meningocócicas/epidemiología , Neisseria meningitidis Serogrupo Y/fisiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Femenino , Humanos , Incidencia , Lactante , Recién Nacido , Masculino , Meningitis Meningocócica/epidemiología , Meningitis Meningocócica/microbiología , Infecciones Meningocócicas/microbiología , Persona de Mediana Edad , Neisseria meningitidis Serogrupo Y/clasificación , Estudios Retrospectivos , Suecia/epidemiología , Adulto JovenRESUMEN
An increase of invasive meningococcal disease caused by Neisseria meningitidis serogroup Y has been noted in Sweden since 2005, and to a lower extent throughout Europe. The present study describes the epidemiology of invasive N. meningitidis isolates in Sweden in the period between 2010 and 2012, with a focus on serogroup Y. We also aimed to find an optimal molecular typing scheme for both surveillance and outbreak investigations. All invasive N. meningitidis isolates in Sweden during the study period (n=208) were genetically characterised. Serogroup Y predominated with 22/57, 31/61 and 44/90 of all invasive isolates (incidence 0.23, 0.33 and 0.46 per 100,000 population) in 2010, 2011 and 2012 respectively. In each of these years, 15/22, 22/31 and 19/44 of serogroup Y isolates were genetically clonal (Y: P1.52,101,362: F41: ST-23(cc23), 'porB allele 336, fHbp allele 25 and penA allele 22). Our findings further support those of others that currently recommended FetA typing could be replaced by FHbp. Moreover, in line with a previous study that we conducted, the current results indicate that highly variable multilocus variable-number tandem repeat analysis (HV-MLVA) can be used as a first-hand rapid method for small outbreak investigations.
Asunto(s)
Infecciones Meningocócicas/epidemiología , Infecciones Meningocócicas/genética , Neisseria meningitidis/genética , Neisseria meningitidis/aislamiento & purificación , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Brotes de Enfermedades , Femenino , Genotipo , Humanos , Incidencia , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , Repeticiones de Minisatélite , Tipificación de Secuencias Multilocus/métodos , Neisseria meningitidis/clasificación , Reacción en Cadena de la Polimerasa/métodos , Vigilancia de Guardia , Análisis de Secuencia de ADN , Serogrupo , Serotipificación , Suecia/epidemiología , Adulto JovenRESUMEN
Neisseria meningitidis serogroups B and C have been responsible for the majority of invasive meningococcal disease in Europe. Recently, an increase of N. meningitidis disease due to serogroup Y has been noted in Sweden (in 2010, the proportion was 39%, with an incidence of 0.23 per 100,000 population), as well as in other northern European countries. We aimed to investigate the clonal pattern of the emerging serogroup Y in Sweden during 2000 to 2010. The serogroup Y isolates identified during this time (n=85) were characterised by multilocus sequence typing and sequencing of the fetA, fHbp, penA, porA and porB genes. The most frequent clone (comprising 28 isolates) with identical allele combinations of the investigated genes, was partly responsible for the observed increased number of N. meningitidis serogroup Y isolates. It was sulfadiazine resistant, with genosubtype P1.5-2,10-1,36-2, sequence type 23, clonal complex 23, porB allele 3-36, fetA allele F4-1, fHbp allele 25 and penA allele 22. The first case with disease due to this clone was identified in 2002: there was a further case in 2004, six during 2006 to 2007, eight during 2008 to 2009, with a peak of 12 cases in 2010. An unusual increase of invasive disease in young adults (aged 2029 years) caused by this clone was shown, but no increase in mortality rate was observed.
Asunto(s)
Enfermedades Transmisibles Emergentes/genética , Enfermedades Transmisibles Emergentes/mortalidad , Predisposición Genética a la Enfermedad/epidemiología , Predisposición Genética a la Enfermedad/genética , Meningitis Meningocócica/genética , Meningitis Meningocócica/mortalidad , Adulto , Humanos , Incidencia , Medición de Riesgo , Factores de Riesgo , Suecia/epidemiologíaRESUMEN
The commercial polymerase chain reaction (PCR) test, SeptiFast, is designed to identify the DNA of individual bacterial and fungal pathogens in whole blood. We aimed to evaluate the usefulness of the test for the detection of community-onset bloodstream infections. We prospectively included adult patients who were subjected to blood culture (BC) at an infectious diseases department. For the evaluation, one BC/PCR set (two BC bottles and one PCR tube) per patient was used. When several sets were obtained and analyzed, the first set with any positive result was evaluated. Among 1,093 consecutively included patients, BC was positive in 138 and PCR was positive in 107. Fifty positive PCR results were supported by BC in the same BC/PCR set, ten were supported by other cultures, and, additionally, ten were supported by the clinical presentation. Compared with BC, PCR showed specificities and negative predictive values of >97% for all detectable pathogens. The following sensitivities and positive predictive values (PPVs) were noted: Staphylococcus aureus, 67% and 43%; Streptococcus pneumoniae, 12% and 67%; other Streptococcus species, 43% and 77%; Escherichia coli, 53% and 56%; and Klebsiella species, 43% and 23%. If support from other cultures and the clinical presentation were included in the reference standard, the PPVs for the detection of these bacteria were 57%, 100%, 92%, 75%, and 69%, respectively. Although the specificities were high, the low sensitivities and suboptimal PPVs noted in the present study discourage routine use of the test in its present form for the detection of community-onset bloodstream infections.
Asunto(s)
Bacteriemia/diagnóstico , Bacteriemia/microbiología , Bacterias/clasificación , Bacterias/aislamiento & purificación , Técnicas Bacteriológicas/métodos , Técnicas de Diagnóstico Molecular/métodos , Reacción en Cadena de la Polimerasa/métodos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Estudios Prospectivos , Sensibilidad y Especificidad , Adulto JovenRESUMEN
In the present study, we evaluated rapid real-time PCR assays for ply, Spn9802, and lytA applied to plasma samples for the detection of Streptococcus pneumoniae in patients with community-acquired pneumonia (CAP). In a prospective study of CAP aetiology, an EDTA plasma sample was collected together with blood culture in 92 adult CAP patients and 91 adult controls. Among the 92 CAP patients, lytA PCR was positive in eight (9%), Spn9802 PCR was positive in 11 (12%) and ply PCR was positive in 19 (21%) cases. Of 91 controls, the ply PCR was positive in eight cases (9%), but no positive cases were noted by Spn9802 or lytA PCRs. Ten CAP patients had pneumococcal bacteraemia. Compared to blood culture, PCR for lytA, Spn9802 and ply had sensitivities of 70% (7/10), 60% (6/10) and 70% (7/10), and specificities of 96% (79/82), 94% (77/82) and 85% (70/82) respectively. With blood culture and/or culture of representative sputum, and/or urinary antigen detection, S. pneumoniae was identified in 31 CAP patients. Compared to these tests in combination, PCR for lytA, Spn9802 and ply showed sensitivities of 26% (8/31), 32% (10/31) and 42% (13/31), and specificities of 100% (61/61), 98% (60/61) and 90% (55/61) respectively. We conclude that Spn9802 and lytA PCRs may be useful for the rapid detection of bacteraemic pneumococcal pneumonia, whereas ply PCR is not specific enough for routine use and blood PCR with small plasma volumes is not useful for the detection of nonbacteraemic pneumococcal pneumonia.
Asunto(s)
Proteínas Bacterianas/genética , Sangre/microbiología , Infecciones Comunitarias Adquiridas/microbiología , ADN Bacteriano/genética , Neumonía Neumocócica/diagnóstico , Reacción en Cadena de la Polimerasa/métodos , Streptococcus pneumoniae/genética , Adulto , Anciano , Anciano de 80 o más Años , Técnicas Bacteriológicas/métodos , ADN Bacteriano/aislamiento & purificación , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Sensibilidad y Especificidad , Streptococcus pneumoniae/aislamiento & purificación , Estreptolisinas/genética , Factores de TiempoRESUMEN
The pneumolysin (ply) gene is widely used as a target in PCR assays for Streptococcus pneumoniae in respiratory secretions. However, false-positive results with conventional ply-based PCR have been reported. The aim here was to study the performance of a quantitative ply-based PCR for the identification of pneumococcal lower respiratory tract infection (LRTI). In a prospective study, fibreoptic bronchoscopy was performed in 156 hospitalized adult patients with LRTI and 31 controls who underwent bronchoscopy because of suspicion of malignancy. Among the LRTI patients and controls, the quantitative ply-based PCR applied to bronchoalveolar lavage (BAL) fluid was positive at >or=10(3) genome copies/mL in 61% and 71% of the subjects, at >or=10(5) genome copies/mL in 40% and 58% of the subjects, and at >or=10(7) genome copies/mL in 15% and 3.2% of the subjects, respectively. Using BAL fluid culture, blood culture, and/or a urinary antigen test, S. pneumoniae was identified in 19 LRTI patients. As compared with these diagnostic methods used in combination, quantitative ply-based PCR showed sensitivities and specificities of 89% and 43% at a cut-off of 10(3) genome copies/mL, of 84% and 66% at a cut-off of 10(5) genome copies/mL, and of 53% and 90% at a cut-off of 10(7) genome copies/mL, respectively. In conclusion, a high cut-off with the quantitative ply-based PCR was required to reach acceptable specificity. However, as a high cut-off resulted in low sensitivity, quantitative ply-based PCR does not appear to be clinically useful. Quantitative PCR methods for S. pneumoniae using alternative gene targets should be evaluated.
Asunto(s)
Infecciones Neumocócicas/diagnóstico , Reacción en Cadena de la Polimerasa/métodos , Infecciones del Sistema Respiratorio/microbiología , Streptococcus pneumoniae/genética , Estreptolisinas/genética , Adulto , Anciano , Anciano de 80 o más Años , Proteínas Bacterianas/genética , Líquido del Lavado Bronquioalveolar/microbiología , Broncoscopía/métodos , Humanos , Persona de Mediana Edad , Estudios Prospectivos , Sensibilidad y EspecificidadRESUMEN
A Chlamydia trachomatis variant that contains a 377 bp deletion in the cryptic plasmid was recently reported in Sweden. This deletion includes the targets for Cobas Amplicor, Cobas TaqMan48, and Abbott m2000. We examined the proportion and characteristics of this variant in Orebro county, Sweden and developed an effective diagnostic solution. In total, 2,401 consecutive C. trachomatis culture samples and 536 PCR samples from symptomatic and asymptomatic patients and screened females were included. Culture, Cobas Amplicor, and LightMix 480HT were used for diagnosis. A mutant-specific PCR, plasmid sequencing, omp1 sequencing and multilocus sequence typing (MLST) were used to identify and characterise mutants. In total, 162 (6.7%) of the cultured samples were positive for C. trachomatis. However, 61 (38%) of those were negative when using Cobas Amplicor, and 60 of these were subsequently confirmed as the new variant. 13 of these mutant isolates were further characterised genetically, and all were of identical genotype E and the unique MLST sequence type: 21, 19, 1, 2, 1. Of all culture-positive samples, 161 of 162 were positive in the LightMix 480HT assay. The single negative sample was only weakly positive in culture, and negative in all PCRs. Of the 536 PCR samples, 37 were positive in both Cobas Amplicor and LightMix 480HT, 13 were only positive in LightMix 480HT (mutants), and two were only positive in Cobas Amplicor. Mutated C. trachomatis were prevalent in Orebro county in the period from October 2006 to February 2007, and it appeared to be a single clone. LightMix 480HT seemed sensitive, specific, and enabled high throughput diagnostics. However, rare low positive samples may be false-negative. Frequent surveillance and evaluations of diagnostic methods worldwide are crucial.
Asunto(s)
Chlamydia trachomatis/genética , Chlamydia trachomatis/aislamiento & purificación , Infecciones por Chlamydiaceae/diagnóstico , Infecciones por Chlamydiaceae/epidemiología , Brotes de Enfermedades/estadística & datos numéricos , Vigilancia de la Población/métodos , Medición de Riesgo/métodos , Brotes de Enfermedades/prevención & control , Variación Genética/genética , Humanos , Incidencia , Mutación , Factores de Riesgo , Suecia/epidemiologíaRESUMEN
The present study assessed the diagnostic usefulness of a multiplex PCR (mPCR) for Streptococcus pneumoniae, Haemophilus influenzae, Mycoplasma pneumoniae and Chlamydophila pneumoniae applied to bronchoalveolar lavage (BAL). Fibreoptic bronchoscopy was performed on 156 hospitalised adult patients with lower respiratory tract infection (LRTI) and 36 controls. BAL fluid was analysed with bacterial culture and mPCR. By conventional diagnostic methods, S. pneumoniae, H. influenzae, M. pneumoniae and C. pneumoniae were aetiological agents in 14, 21, 3.2 and 0% of the LRTI patients, respectively. These pathogens were identified by BAL mPCR in 28, 47, 3.2 and 0.6% of cases, respectively, yielding sensitivities of 86% for S. pneumoniae, 88% for H. influenzae, 100% for M. pneumoniae and 0% for C. pneumoniae, and specificities of 81, 64, 100 and 99% for S. pneumoniae, H. influenzae, M. pneumoniae and C. pneumoniae, respectively. Of the 103 patients who had taken antibiotics prior to bronchoscopy, S. pneumoniae was identified by culture in 2.9% and by mPCR in 31%. Among the controls, mPCR identified S. pneumoniae in 11% and H. influenzae in 39%. In lower respiratory tract infection patients, bronchoalveolar lavage multiplex PCR can be useful for identification of Streptococcus pneumoniae, Mycoplasma pneumoniae and Chlamydophila pneumoniae. The method appears to be particularly useful in patients treated with antibiotics.
Asunto(s)
Líquido del Lavado Bronquioalveolar/microbiología , Haemophilus influenzae/aislamiento & purificación , Mycoplasma pneumoniae/aislamiento & purificación , Neumonía Bacteriana/diagnóstico , Reacción en Cadena de la Polimerasa/métodos , Streptococcus pneumoniae/aislamiento & purificación , Adulto , Anciano , Anciano de 80 o más Años , Lavado Broncoalveolar , ADN Bacteriano/análisis , Femenino , Haemophilus influenzae/genética , Humanos , Masculino , Persona de Mediana Edad , Mycoplasma pneumoniae/genética , Neumonía Bacteriana/microbiología , Reacción en Cadena de la Polimerasa/normas , Streptococcus pneumoniae/genéticaRESUMEN
The aim of the study was to determine the concentrations of serum antibodies against Haemophilus influenzae type b in preschool children in relation to the distribution of idiotypic antibodies 1 and 2 (Id-1 and Id-2) and the exposure to breastfeeding in infancy. Sera were obtained from 74 control children recruited in an earlier case-control study before the introduction of general Hib vaccination. Duration of breastfeeding was monitored, and prevalence of noninvasive infections was registered. Concentrations of IgG1 and IgG2 anti-Hib, as well as of total Id-1 and Id-2, were determined in ELISA. The expression of Id-1 antibodies increased with age in contrast to the Id-2 antibodies that were found only in children up to 24 months of age. Expression of Id-1 antibodies was positively correlated with higher anti-Hib levels of both the IgG1 and IgG2 isotype. Children expressing Id-2 antibodies showed higher IgG2 anti-Hib concentrations than those who did not have Id-2 (P = 0.001). The concentrations of neither Id-1 nor Id-2 antibodies were related to the duration of breastfeeding. Duration of breastfeeding was related to increased anti-Hib IgG2 in healthy children above 18 months of age. These study shows that the expression of idiotype-1 and idiotype-2 antibodies was associated with higher IgG2 anti-Hib concentration and that breastfeeding could enhance the anti-Hib IgG2 production in children.
Asunto(s)
Anticuerpos Antibacterianos/sangre , Lactancia Materna , Infecciones por Haemophilus/inmunología , Haemophilus influenzae tipo b/inmunología , Inmunoglobulina G/sangre , Idiotipos de Inmunoglobulinas/biosíntesis , Femenino , Vacunas contra Haemophilus/inmunología , Humanos , Idiotipos de Inmunoglobulinas/sangre , Lactante , MasculinoRESUMEN
BACKGROUND: Antibodies present in coeliac disease may occur in IgA-nephropathy. This raises the question of food intolerance in the disease. Evidence for a true correlation between the two disorders has however been scarce. DESIGN: Sera from 89 patients with IgA-nephropathy and 13 other patients with IgA deposits in the glomeruli of kidney biopsies were analysed for IgA-antibodies to gliadin, endomysium and tissue transglutaminase (92/102 patients). RESULTS: Eleven out of 89 (12.4%) of the patients with IgA-nephropathy and five of the 13 others (38%) had elevated titres of IgA-antibodies to gliadin but, in all cases but one, normal IgA-antibodies to endomysium. Patients with IgA-nephropathy and elevated IgA-antibodies to gliadin had elevated total serum IgA more frequently than patients who had not (p<0.01). Two patients with IgA-nephropathy and one with Hennoch Schönlein's purpura had elevated IgA-antibodies to tissue transglutaminase. Small bowel biopsy in 7 out of 11 IgA-antibodies to gliadin positive patients with IgA-nephropathy was pathologic in three cases (two with Marsh I) . One patient with chronic glomerulnephritis also had Marsh I. CONCLUSIONS: We found no increased frequency of verified coeliac disease in 89 patients with IgA-nephropathy. Two patients with IgA-nephropathy and one patient with chronic glomerulonephritis with IgA deposits in the kidney biopsy had a Marsh I histopathology. The findings suggest a possible link of celiac disease to IgA-nephropathy and a role for antibodies to food antigens in this disorder.
Asunto(s)
Duodeno/inmunología , Duodeno/patología , Gliadina/inmunología , Glomerulonefritis por IGA/inmunología , Glomerulonefritis por IGA/patología , Inmunoglobulina A/sangre , Adulto , Anciano , Autoanticuerpos/sangre , Enfermedad Celíaca/complicaciones , Enfermedad Celíaca/inmunología , Enfermedad Celíaca/patología , Femenino , Proteínas de Unión al GTP , Glomerulonefritis por IGA/complicaciones , Humanos , Masculino , Persona de Mediana Edad , Proteína Glutamina Gamma Glutamiltransferasa 2 , Transglutaminasas/inmunologíaRESUMEN
In 2000 the global outbreak that began in Saudi Arabia was caused by a W135:2a:P1.5,2 strain of Neisseria meningitidis belonging to the ET-37 complex and to ST-11. There was concern that introduction of this epidemic clone (EC) might lead to a wave of outbreaks in the African meningitis belt. The WHO therefore initiated studies of meningococcal carriage among pilgrims and their family contacts in Morocco, Oman and Sudan, 3 to 12 months after the Hajj 2000. In Morocco, 1186 persons were swabbed 3 times. Ninety-five meningococcal strains were isolated from 2.7% of the specimens. Pulsed-field gel electrophoresis showed that 32 (33.6%) were identical with the EC. In Sudan, 5 strains identical with the EC were obtained after sampling 285 persons. In Oman, among 18 meningococcal strains isolated from 399 subjects, 11 (61.1%) belonged to the EC. The important pharyngeal carriage of W135 (EC) and its role in the 2001-2002 outbreaks in Burkina Faso argues for the necessity of reinforcing surveillance, and adapting and planning responses in Africa and the Middle East using the most appropriate vaccine.
Asunto(s)
Portador Sano , Meningitis Meningocócica/epidemiología , Neisseria meningitidis Serogrupo W-135/aislamiento & purificación , Faringe/microbiología , Brotes de Enfermedades , Electroforesis en Gel de Campo Pulsado , Salud de la Familia , Humanos , Masculino , Marruecos , Neisseria meningitidis Serogrupo W-135/clasificación , Neisseria meningitidis Serogrupo W-135/genética , Omán , Polimorfismo de Longitud del Fragmento de Restricción , Serotipificación , SudánRESUMEN
Although the PCR for the detection of Bordetella pertussis is routinely performed in diagnostic laboratories, no quality assessment program has so far been described. We report on the results obtained with two external quality assessment proficiency panels sent to European laboratories. The first proficiency panel contained a series of dilutions of three previously characterized B. pertussis clinical isolates and two negative controls. No false-positive results were reported by six laboratories providing seven data sets. The reported limits of detection of the three B. pertussis strains varied between 4 and 4,000, 9 and 9,000, and 3 and 30,000 CFU/ml, respectively. The second proficiency panel, composed of a series of dilutions of reference strains of B. pertussis, B. holmesii, B. hinzii, and B. bronchiseptica, as well as negative controls, was sent to nine laboratories. One laboratory reported a negative result for a sample and reported a B. parapertussis-positive sample to be positive for B. pertussis. By using the B. pertussis-specific target gene pertactin, one laboratory detected B. pertussis with 100% specificity. All other laboratories, which used IS481-based assays, reported positive results for the samples containing B. holmesii and B. bronchiseptica, species that have occasionally been recovered from human respiratory samples. These data show that the choice of the target gene is particularly critical for the species specificity of B. pertussis PCR assays.
Asunto(s)
Bordetella pertussis/aislamiento & purificación , ADN Bacteriano/análisis , Tos Ferina/microbiología , Bordetella pertussis/genética , Europa (Continente) , Reacciones Falso Positivas , Humanos , Laboratorios , Reacción en Cadena de la Polimerasa , Control de Calidad , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
OBJECTIVE: Analysis of antibodies against tissue transglutaminase (tTG) has been shown valuable in the diagnosis of coeliac disease (CD) but how quickly serum titres decrease after introduction of a gluten-free diet (GFD) is not known in adults. CD is a well-recognized disorder amongst the general population and many persons try a GFD for fairly vague symptoms before they seek medical advice. Therefore, it is important to determine the time that the serologic tests remain predictive of the disease after the introduction of a GFD. METHODS: Sera were taken from 22 consecutively biopsy-proven adult patients with CD in connection with the diagnostic biopsy. The patients were followed for 1 year and sera were taken after 1, 3, 6 and 12 months after start of a GFD. Sera were stored at -20 degrees C and analysed for IgA antibodies against gliadin, endomysium and two different commercial tTG assays based on recombinant human tTG (tTGrh) and guinea-pig liver (tTGgp). RESULTS: Twenty patients could be followed during GFD and all antibody titres fell sharply within 1 month after introduction of a GFD and continued to decline during the survey interval. Thirty days after beginning the diet only 58, 84, 74 and 53% of all patients had positive antibody levels of tTGrh, tTGgp, EmA and AGA respectively. CONCLUSIONS: As the antibodies used to confirm the diagnosis of CD fall rapidly and continue to decline following the introduction of a GFD, it is important that health care providers carefully inquire about the possibility of self-prescribed diets before patients sought medical attention.
Asunto(s)
Enfermedad Celíaca/inmunología , Dieta con Restricción de Proteínas/métodos , Inmunoglobulina A/sangre , Transglutaminasas/inmunología , Adulto , Anciano , Anciano de 80 o más Años , Enfermedad Celíaca/sangre , Enfermedad Celíaca/diagnóstico , Femenino , Glútenes/administración & dosificación , Humanos , Inmunoglobulina A/inmunología , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Proteínas Recombinantes/sangre , Factores de TiempoRESUMEN
OBJECTIVES: To evaluate and compare the performances of three enzyme-immunoassays (EIAs) and a double radial immunodiffusion (DRID) test in addition to immunofluorescence (IF) microscopy for routine laboratory screening of patient sera sent for antinuclear antibody (ANA) analysis. METHODS: 3079 consecutive patient sera sent for routine testing of ANA were analysed by IF microscopy on HEp-2 cells (IF-ANA), three different ANA-EIAs, and a DRID test for antibodies against extractable nuclear antigens. The IF-ANA and DRID tests were regarded as reference methods. RESULTS: By IF-ANA and/or DRID, 375 sera (12%) turned out ANA-positive. A further 171 sera (6%) were positive by EIA, but could not be confirmed either by IF microscopy or DRID. 32 of the 375 ANA-positive (9%) sera were negative by IF microscopy, but had precipitating antibodies against Ro/SS-A (52 and/or 60 kD). CONCLUSIONS: Different assays for ANA analysis give overlapping results to a certain extent, but are by no means interchangeable. Thus, different ANA tests reflect different aspects of these autoantibodies. The diagnostic utility of ANA testing still mainly refers to IF-microscopy and precipitin tests. IF-ANA should not be abandoned as the golden standard in clinical routine, until diagnostic and classification criteria for systemic lupus erythematosus and other systemic inflammatory autoimmune diseases have been revised. However, in addition we strongly advocate that a specific test for anti-Ro/SS-A antibodies is always included.
Asunto(s)
Anticuerpos Antinucleares/inmunología , Lupus Eritematoso Sistémico/diagnóstico , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Anticuerpos Antinucleares/sangre , Niño , Preescolar , Femenino , Técnica del Anticuerpo Fluorescente/métodos , Humanos , Lactante , Lupus Eritematoso Sistémico/inmunología , Masculino , Persona de Mediana Edad , Suero/inmunologíaRESUMEN
Outer membrane protein (OMP) vaccines are being developed against Neisseria meningitidis serogroup B which may provide protection against common circulating serotypes and serosubtypes in some countries. However, limited data is available in Europe from genosubtyping meningococci. We therefore undertook a retrospective analysis of the three main variable regions, VR1, VR2 as well as VR3, of the porA gene from N. meningitidis isolated from different countries, mainly from Scotland and Sweden. Analysis of this gene showed that, amongst 226 strains studied, there were a total of 78 different strains. No new VR1 or VR2 alleles were found but five new VR3 alleles are described. Our data indicates the importance of analysing the VR3 region of PorA in addition to VR1 and VR2 and also highlights, in general terms, the need for genosubtyping meningococci. Such analyses have major implications for the design of new meningococcal vaccines.
Asunto(s)
Vacunas Bacterianas/inmunología , Neisseria meningitidis/inmunología , Porinas/genética , Secuencia de Aminoácidos , Secuencia de Bases , Cartilla de ADN , ADN Bacteriano/genética , Europa (Continente) , Amplificación de Genes , Genotipo , Neisseria meningitidis/clasificación , Neisseria meningitidis/genética , Porinas/química , Porinas/inmunologíaRESUMEN
A method for detection and genotyping of genital Chlamydia trachomatis infections based on omp1 gene amplification and sequencing was developed. DNA was extracted from urogenital or urine samples using a Chelex-based method, and an approximately 1,100-bp-long fragment from the omp1 gene was directly amplified and sequenced. Genotyping was performed by BLAST similarity search, and phylogenetic tree analysis was used to illustrate the evolutionary relationships between clinical isolates and reference strains. The method was used to determine the genotypes of C. trachomatis in 237 positive urogenital and/or urine specimens collected at a Swedish sexually transmitted disease clinic during 1 year. The most common genotypes corresponded to serotypes E (47%) and F (17%). The omp1 gene was highly conserved for genotype E (106 of 112 samples without any mutation) and F (41 of 42 samples without any mutation) strains but appear slightly less conserved for genotypes G (n = 6) and H (n = 6), where the sequences displayed one to four nucleotide substitutions relative to the reference sequence. Genotyping of samples collected at the follow-up visit indicated that two patients had become reinfected, while three other patients suffered treatment failure or reinfection. One woman appeared to have a mixed infection with two different C. trachomatis strains. This omp1 genotyping method had a high reproducibility and could be used for epidemiological characterization of sexually transmitted Chlamydia infections.
Asunto(s)
Atención Ambulatoria , Infecciones por Chlamydia/microbiología , Chlamydia trachomatis/clasificación , Porinas/genética , Enfermedades Bacterianas de Transmisión Sexual/microbiología , Adolescente , Adulto , Anciano , Técnicas de Tipificación Bacteriana , Infecciones por Chlamydia/diagnóstico , Infecciones por Chlamydia/epidemiología , Chlamydia trachomatis/genética , Chlamydia trachomatis/metabolismo , Femenino , Enfermedades Urogenitales Femeninas/diagnóstico , Enfermedades Urogenitales Femeninas/epidemiología , Enfermedades Urogenitales Femeninas/microbiología , Genotipo , Humanos , Masculino , Enfermedades Urogenitales Masculinas , Persona de Mediana Edad , Filogenia , Reacción en Cadena de la Polimerasa , Análisis de Secuencia de ADN , Enfermedades Bacterianas de Transmisión Sexual/diagnóstico , Enfermedades Bacterianas de Transmisión Sexual/epidemiología , Suecia/epidemiología , Orina/microbiología , Sistema Urogenital/microbiologíaRESUMEN
An outbreak of serogroup W-135 meningococcal disease was reported among pilgrims returning from the annual hajj (pilgrimage to Mecca) in mid-March 2000. Molecular characterization was used to investigate the similarity of the hajj-associated W-135 strains with those isolated in Sweden during a 23-year period (1978 to 2000). The same hajj-associated genosubtype, genosubtype P1.5,2,36b, has been documented in Sweden since 1979, while pulsed-field gel electrophoresis and the sulfadiazine resistance of the W-135 isolates indicated that the outbreak was probably due to a new clone of W-135 meningococci.
Asunto(s)
Brotes de Enfermedades , Islamismo , Infecciones Meningocócicas/epidemiología , Neisseria meningitidis/clasificación , Neisseria meningitidis/genética , Viaje , Electroforesis en Gel de Campo Pulsado , Genotipo , Humanos , Infecciones Meningocócicas/microbiología , Neisseria meningitidis/efectos de los fármacos , Neisseria meningitidis/aislamiento & purificación , Porinas/genética , Arabia Saudita/epidemiología , Serotipificación , Suecia/epidemiologíaRESUMEN
The prevalence of celiac disease (CD) in Sweden is about 4 cases per 1,000 people. Screening for CD with serological tests indicates similar high prevalences in many other countries. Between 1 November 1992 and 30 April 1995, 133 children (9 months to 16.7 years of age) with suspected CD were studied. The predictive value (PV) of immunoglobulin A antigliadin antibodies (IgA-AGA) in the serum as assayed with two new commercial automated immunoassays--the Pharmacia CAP System Gliadin IgA FEIA (CAP) and the UNICAP-100 (UNICAP)--and with three "in-house" methods was evaluated using assessment of the small intestinal mucosa morphology as the "gold standard." All serum samples were analyzed for total serum IgA. At presentation the diagnostic sensitivities and specificities of the different tests varied from 0.72 to 0.88 and 0.67 to 0.87, respectively. All methods showed a higher sensitivity for CD in younger children. The area under each assay's receiver operating characteristic curve was calculated and varied between 0.82 and 0.89. The positive and negative PVs for the CAP and UNICAP, which were assays with a high sensitivity and a high specificity, respectively, were estimated. In the clinically selected population (prevalence of CD, 1 in 3) the positive PV was about 55%, and in the general population (prevalence, 1 in 250) it was about 1%. The negative PVs for both CAP and UNICAP were close to 100%; thus, when the AGA test was negative, the risk for CD was small. Interestingly, five children had serum IgA levels below the detection limit (<0.07 g/liter) when on a gluten-free diet, whereas they had normal levels at the time of the first biopsy. In conclusion, the automated immunoassays--based on ImmunoCAP technology--for analysis of IgA-AGA had a reliability comparable to that of the in-house methods.