Antigenuria positiva a neumococo y vacunación / Positive urine pneumococcal antigen test and vaccination

Introducción y objetivo: La detección del antígeno neumocócico en orina es una prueba útil pero puede presentar falsos positivos, entre ellos, la vacunación neumocócica. Material y métodos: Detección de las antigenurias positivas a neumococo en el Hospital de Denia (enero-febrero/2015). Se determinaron variables epidemiológicas, radiológicas, microbiológicas y antecedente de vacunación neumocócica (neumo-23 y/o neumo-13). Resultados: La antigenuria a neumococo mostró un resultado positivo en el 12,4% de 385 determinaciones. Solo en el 33,3% de los casos con antigenuria positiva se documentó infiltrado radiológico en la radiografía de tórax. En el 35,4% de los pacientes existía antecedente de vacunación neumocócica previa. En la mayor parte de los casos (87,5%) un antígeno neumocócico positivo supuso la prescripción de un tratamiento antibiótico. Conclusiones: La vacunación neumocócica puede generar falsos positivos a la antigenuria por neumococo en la práctica clínica, con la consiguiente prescripción innecesaria de antibióticos en gran número de casos (AU)

Introduction and objective: Although urine pneumococcal antigen is an useful test, it has false positives such as pneumococcal vaccination. Material and methods: Positive urine pneumococcal antigen in Hospital de Denia (January-February/2015). We studied epidemiological, radiological and microbiological variables as well as previous pneumococcal vaccination (neumo-23 and/or neumo-13). Results: Urine pneumococcal antigen test was positive in 12.4% of 385 cases. Only 33.3% of positive cases had pneumonia in chest X-ray, and 35.4% of patients had previous pneumococcal vaccination. In most cases (87.5%), an antibiotic was prescribed. Conclusions: Pneumococcal vaccination can produce a false positive result in the urine pneumococcal antigen test in clinical practice, leading to an unnecessary prescription of antibiotics (AU)

[Positive urine pneumococcal antigen test and vaccination]. / Antigenuria positiva a neumococo y vacunación.

INTRODUCTION AND OBJECTIVE: Although urine pneumococcal antigen is an useful test, it has false positives such as pneumococcal vaccination. MATERIAL AND METHODS: Positive urine pneumococcal antigen in Hospital de Denia (January-February/2015). We studied epidemiological, radiological and microbiological variables as well as previous pneumococcal vaccination (neumo-23 and/or neumo-13). RESULTS: Urine pneumococcal antigen test was positive in 12.4% of 385 cases. Only 33.3% of positive cases had pneumonia in chest X-ray, and 35.4% of patients had previous pneumococcal vaccination. In most cases (87.5%), an antibiotic was prescribed. CONCLUSIONS: Pneumococcal vaccination can produce a false positive result in the urine pneumococcal antigen test in clinical practice, leading to an unnecessary prescription of antibiotics.

Utilización de diferentes técnicas de biología molecular integradas en un algoritmo de identificación de micobacterias no tuberculosas / Use of different PCR-based techniques integrated into a non-tuberculous identification algorithm

Introducción El objetivo del presente trabajo fue demostrar la utilidad de un algoritmo de identificación de micobacterias no tuberculosas (MNT) que integra diferentes técnicas de biología molecular y características fenotípicas básicas. Además se ha realizado una actualización del algoritmo de interpretación del análisis del patrón de restrición de hsp65 (PRA hsp65).Métodos La manera elegida de trabajar consistió en la identificación mediante hibridación con sondas de ADN seguido de PRA hsp65 en aquellos aislados que no pudieron ser identificados mediante hibridación con sondas de ADN. En caso necesario se realizó secuenciación del 16S rDNA y hsp65.ResultadosSe aislaron 236 MNT. De ellos, 102 (43,2%) aislados fueron identificados mediante hibridación con sondas de ADN y 76 (32,2%) mediante PRA hsp65. En los 58 (24,5%) aislados restantes se secuenció 16S rDNA, lo cual permitió la identificación de 53 (22,4%). Para 5 (2,1%) aislados se secuenció hsp65 y permitió la identificación de un aislado más. Cuatro (1,7%) aislados no pudieron ser identificados. Tres nuevos patrones de PRA hsp65 fueron encontrados. Siete aislamientos hibridaron con la sonda AccuProbe Mycobacterium avium complex Identification pero no lo hicieron con las sondas específicas de especie incluidas en el MAC. Cinco y 2 aislados fueron identificados como M. intracellulare y Mycobacterium colombiense, respectivamente. Conclusión Este esquema de trabajo nos permitió la identificación de casi todas las MNT encontradas en este estudio, incluyendo especies recientemente descritas(AU)

Introduction The aim of the present work was to demonstrate the utility of a non-tuberculous mycobacteria (NTM) identification algorithm, which integrates different PCR-based techniques and basic phenotypic features. Moreover, the algorithm for pattern restriction analysis of hsp65 (hsp65 PRA) interpretation has been updated. Methods The workflow chosen consisted of the identification by a DNA hybridization probe method, followed by PCR-restriction enzyme analysis of hsp65 (hsp65 PRA) in those isolates that cannot be identified by hybridization probes. If necessary, 16S rRNA gene and hsp65 gene sequencing were used for speciation. Results A total of 236 NTM were collected, in which 102 (43.2%) isolates were identified by DNA specific probes and 76 (32.2%) isolates were identified with hsp65 PRA. Partial sequencing of the 16S rRNA gene was used for species identification of the remaining 58 (24.5%) isolates. Fifty-three (22.4%) were identified using this method. Five isolates (2.1%) were submitted for partial sequencing of hsp65 gene and one isolate was identified with this method. Four strains (1.7%) could not be identified at species level. Three new PRA patterns were found. Seven isolates tested positive with the AccuProbe Mycobacterium avium complex identification test but did not test positive with the M. avium or Mycobacterium intracellulare specific probes. Five and two of these isolates were identified as M. intracellulare and Mycobacterium colombiense, respectively. Conclusion This approach allowed us to identify almost all NTM isolates found in this study, including some recently described species(AU)

[Use of different PCR-based techniques integrated into a non-tuberculous identification algorithm]. / Utilización de diferentes técnicas de biología molecular integradas en un algoritmo de identificación de micobacterias no tuberculosas.

INTRODUCTION: The aim of the present work was to demonstrate the utility of a non-tuberculous mycobacteria (NTM) identification algorithm, which integrates different PCR-based techniques and basic phenotypic features. Moreover, the algorithm for pattern restriction analysis of hsp65 (hsp65 PRA) interpretation has been updated. METHODS: The workflow chosen consisted of the identification by a DNA hybridization probe method, followed by PCR-restriction enzyme analysis of hsp65 (hsp65 PRA) in those isolates that cannot be identified by hybridization probes. If necessary, 16S rRNA gene and hsp65 gene sequencing were used for speciation. RESULTS: A total of 236 NTM were collected, in which 102 (43.2%) isolates were identified by DNA specific probes and 76 (32.2%) isolates were identified with hsp65 PRA. Partial sequencing of the 16S rRNA gene was used for species identification of the remaining 58 (24.5%) isolates. Fifty-three (22.4%) were identified using this method. Five isolates (2.1%) were submitted for partial sequencing of hsp65 gene and one isolate was identified with this method. Four strains (1.7%) could not be identified at species level. Three new PRA patterns were found. Seven isolates tested positive with the AccuProbe Mycobacterium avium complex identification test but did not test positive with the M. avium or Mycobacterium intracellulare specific probes. Five and two of these isolates were identified as M. intracellulare and Mycobacterium colombiense, respectively. CONCLUSION: This approach allowed us to identify almost all NTM isolates found in this study, including some recently described species.

Diagnostic accuracy of a 16S ribosomal DNA gene-based molecular technique (RT-PCR, microarray, and sequencing) for bacterial meningitis, early-onset neonatal sepsis, and spontaneous bacterial peritonitis.

The diagnostic accuracy of a 16S ribosomal DNA (rDNA) gene-based molecular technique for bacterial meningitis (BM), early-onset neonatal sepsis (EONS), and spontaneous bacterial peritonitis (SBP) is evaluated. The molecular approach gave better results for BM diagnosis: sensitivity (S) was 90.6% compared to 78.1% for the bacterial culture. Percentages of cases correctly diagnosed (CCD) were 91.7% and 80.6%, respectively. For EONS diagnosis, S was 60.0% for the molecular approach and 70.0% for the bacterial culture; and CCD was 95.2% and 96.4%, respectively. For SPB diagnosis, the molecular approach gave notably poorer results than the bacterial cultures. S and CCD were 48.4% and 56.4% for the molecular approach and 80.6% and 89.1% for bacterial cultures. Nevertheless, bacterial DNA was detected in 53.3% of culture-negative samples. Accuracy of the 16S rDNA PCR approach differs depending on the sample, the microorganisms involved, the expected bacterial load, and the presence of bacterial DNA other than that from the pathogen implied in the infectious disease.

Lymphadenopathy caused by Mycobacterium colombiense.

We report the case of a 3-year-old girl with lymphadenopathy caused by the recently described species Mycobacterium colombiense. M. colombiense is a nonpigmented slow grower that is included in the Mycobacterium avium complex. Partial sequencing of the 16S rRNA gene was used for species identification.