Evaluación del parámetro BACT-info del citómetro de flujo UF-5000 (Sysmex) para la clasificación gram en infección del tracto urinario / Evaluation of Sysmex UF-5000 flow cytometer flag BACT-info for Gram discrimination in urinary tract infection

Introducción: El urocultivo como gold standard para diagnóstico de infección del tracto urinario (ITU) supone una carga de trabajo considerable en los Servicios de Microbiología Clínica, debido al elevado número de muestras recibidas que finalmente serán negativas. Por ello, utilizar sistemas de cribado que además reduzcan el tiempo de respuesta del diagnóstico de ITU es necesario. El nuevo citómetro de flujo UF-5000 (Sysmex Corporation) es capaz de diferenciar entre bacterias gramnegativas y grampositivas mediante el parámetro BACT-info según el fabricante. El objetivo de nuestro estudio fue evaluar la capacidad de discriminación gram del citómetro UF-5000. Métodos: Estudio prospectivo de 449 orinas recogidas de forma consecutiva, en el período 7/3/2022-27/5/2022, en las que se comparó el flag BACT-info con el urocultivo como método de referencia. Resultados: La sensibilidad obtenida tanto para bacterias gramnegativas como positivas fue superior al 95%. Sin embargo, en el caso de bacterias grampositivas, el índice Kappa moderado (0,49) y el valor predictivo positivo bajo (37,1%) indicó que la correlación entre el flag BACT-info y el urocultivo no era aceptable, por lo que no sería recomendable informarlo al clínico peticionario. Conclusión: El uso del citómetro UF-5000 supone un adelanto en la orientación etiológica de las ITUs causadas por bacterias gramnegativas. Informar la morfología gram en la muestra de orina reduce el tiempo de respuesta en el diagnóstico microbiológico de ITU, lo que tendría un impacto en la disminución y optimización del tratamiento empírico, y, por ende, en la generación de resistencias antimicrobianas. (AU)

Introduction. Urine culture as a gold standard for the diagnosis of urinary tract infection (UTI) involves a considerable workload in Clinical Microbiology Departments, due to the high number of samples received that will ultimately be negative. Therefore, it is necessary to use screening systems that also reduce the turnaround time for UTI diagnosis. The new flow cytometer UF-5000 (Sysmex Corporation) is able to differentiate between Gram-negative and Gram-positive bacteria using the BACT-info parameter according to manufacturer. The aim of our study was to evaluate the gram discrimination ability of the UF-5000 cytometer. Methods. A prospective study with 449 urine samples collected consecutively was conducted, in the period 7/3/2022- 27/5/2022, in which the BACT-info flag was compared with urine culture as the reference method. Results. The sensitivity obtained for both Gram-negative and Gram-positive bacteria was above 95%. However, for Gram-positive bacteria, the moderate Kappa index (0.49) and the low positive predictive value (37.1%) indicated that the correlation between BACT-info flag and urine culture was not acceptable and should not be reported to the requesting clinician. Conclusion. Implementation of the third generation UF5000 cytometer represents a significant advance in the aetiological orientation of UTIs caused by Gram-negative bacteria. Reporting the Gram morphology in the urine samples reduces the response time in the microbiological diagnosis of UTI, which would have an impact on the reduction and optimisation of empirical treatment, and thus on the generation of antimicrobial resistance. (AU)

Description of eight human infections caused by Bacteroides pyogenes in a tertiary hospital of northern Spain.

Bacteroides pyogenes is a Gram-negative obligate anaerobe, saccharolytic, non-motile, non-pigment-producing and non-spore-forming rod. Reports of human infections caused by B. pyogenes are scarce, with approximately 30 cases documented in scientific literature. The aim of this study was to describe the clinical characteristics of 8 different patients and to study the in vitro antibiotic susceptibility of the strains, as well as to evaluate the in vivo activity of the prescribed treatments. We conducted a descriptive retrospective study by searching all B. pyogenes isolates from January 2010 to March 2023 at the Basurto University Hospital. This included all cases, both in monomicrobial or polymicrobial cultures. Among the eight patients, three experienced severe infections such as bacteremia and osteomyelitis. All the strains were susceptible to amoxicillin/clavulanic acid, piperacillin/tazobactam, imipenem, meropenem, clindamycin, metronidazole and moxifloxacin.

A case of septic arthritis caused by Capnocytophaga canimorsus in an HIV patient.

Invasive infections caused by Capnocytophaga canimorsus , a Gram-negative rod found in the oral cavity of healthy dogs and cats, are rare but they are increasing worldwide. We report a case of septic arthritis in a native knee joint due to this micro-organism. A 57-year-old man, with a well-controlled chronic HIV infection, attended the Emergency Department because of left knee pain and shivering without measured fever. A knee arthrocentesis and a computed tomography scan were performed, revealing septic arthritis with collections in the left leg posterior musculature. He was admitted to the Infectious Diseases Department for antibiotic treatment. Initial synovial fluid was inoculated in blood culture bottles, and the anaerobic one was positive after 63 h. Gram stain revealed fusiform Gram-negative rods, identified as C. canimorsus by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF) directly from the bottle. Identification was confirmed by 16S rRNA sequencing and serotyping was performed by PCR, with serovar A as the outcome. Due to an unfavourable clinical course, the patient required two surgical cleanings and after appropriate antibiotic treatment he was discharged 2 months later.

Evaluation of Vitek-MS(TM) and Microflex LT(TM) commercial systems for identification of Acinetobacter calcoaceticus-baumannii complex / Evaluación de los sistemas comerciales Vitek(R) MS y Microflex(R) LT para la identificación del complejo Acinetobacter calcoaceticus-baumannii

INTRODUCTION: Acinetobacter is a genus that comprises a group of opportunistic pathogens responsible for a variety of nosocomial infections. The Acinetobacter calcoaceticus-Acinetobacter baumannii (Acb) complex includes some species of clinical importance, mainly A. baumannii, A. pittii and A. nosocomialis, which share phenotypic similarities that make it very difficult to distinguish between them using a phenotypic approach. The aim of this study was to evaluate two commercial matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) systems for the identification of different Acinetobacter species, with a special focus among those belonging to the Acb complex. METHODS: One hundred and fifty-six Acinetobacter spp. clinical strains, identified by amplified ribosomal DNA restriction analysis (ARDRA) and rpoB gene sequencing, were analysed by two different MALDI-TOF systems. RESULTS: Considering only the 144 strains of the Acb complex evaluated in this study, the Vitek-MS(TM) and Microflex LT(TM) systems correctly identified 129 (89.6%) and 143 (99.3%) strains, respectively. CONCLUSION: After analysing 156 strains belonging to Acinetobacter spp., both Vitek-MS(TM) and Microflex LT(TM) proved to be rapid and accurate systems for the identification of Acb complex species showing a good correlation. However, both manufacturers should improve their databases to include new species in them

INTRODUCCIÓN: Acinetobacter es un género que comprende un grupo de patógenos oportunistas responsables de varias infecciones nosocomiales. El complejo Acinetobacter calcoaceticus-Acinetobacter baumannii (Acb) reúne algunas especies de importancia clínica, principalmente A. baumannii, A. pittii y A. nosocomialis, que comparten similitudes fenotípicas que hacen muy difícil poder discriminar entre ellas utilizando un enfoque fenotípico. El objetivo de este estudio fue evaluar 2 sistemas comerciales de espectrometría de masas de ionización por láser asistido con una matriz (MALDI-TOF MS) para la identificación de diferentes especies de Acinetobacter, con un enfoque especial entre los que pertenecen al complejo Acb. MÉTODOS: Analizamos 156 cepas clínicas de Acinetobacter spp., identificadas mediante análisis de restricción de ADN ribosomal amplificado (ARDRA) y secuenciación del gen rpoB, por 2 sistemas diferentes de MALDI-TOF. RESULTADOS: Teniendo en cuenta solo las 144 cepas del complejo Acb evaluadas en este estudio, los sistemas Vitek(R) MS y Microflex(R) LT identificaron correctamente 129 (89,6%) y 143 (99,3%) cepas, respectivamente. CONCLUSIÓN: Después de analizar 156 cepas pertenecientes a Acinetobacter spp., Vitek(R) MS y Microflex(R) LT demostraron ser sistemas rápidos y precisos para la identificación de especies del complejo Acb mostrando una buena correlación. Sin embargo, ambos fabricantes deberían mejorar sus bases de datos incluyendo nuevas especies en ellas

Evaluation of Vitek-MS™ and Microflex LT™ commercial systems for identification of Acinetobacter calcoaceticus-baumannii complex.

INTRODUCTION: Acinetobacter is a genus that comprises a group of opportunistic pathogens responsible for a variety of nosocomial infections. The Acinetobacter calcoaceticus-Acinetobacter baumannii (Acb) complex includes some species of clinical importance, mainly A. baumannii, A. pittii and A. nosocomialis, which share phenotypic similarities that make it very difficult to distinguish between them using a phenotypic approach. The aim of this study was to evaluate two commercial matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) systems for the identification of different Acinetobacter species, with a special focus among those belonging to the Acb complex. METHODS: One hundred and fifty-six Acinetobacter spp. clinical strains, identified by amplified ribosomal DNA restriction analysis (ARDRA) and rpoB gene sequencing, were analysed by two different MALDI-TOF systems. RESULTS: Considering only the 144 strains of the Acb complex evaluated in this study, the Vitek-MS™ and Microflex LT™ systems correctly identified 129 (89.6%) and 143 (99.3%) strains, respectively. CONCLUSION: After analysing 156 strains belonging to Acinetobacter spp., both Vitek-MS™ and Microflex LT™ proved to be rapid and accurate systems for the identification of Acb complex species showing a good correlation. However, both manufacturers should improve their databases to include new species in them.

Evaluación del citómetro de flujo Sysmex UF-1000i(R) como método de cribado de bacteriuria asintomática y estreptococo grupo B en la mujer embarazada / Evaluation of Sysmex UF-1000(R) flow cytometer as a screening method for asymptomatic bacteriuria and detection of Group B Streptococcus in pregnancy

OBJETIVOS: Aunque se ha generalizado el uso de la citometría de flujo como método automatizado de cribado previo al urocultivo, los puntos de corte óptimos para cada grupo poblacional no están homogéneamente establecidos. El objetivo del presente estudio ha sido determinar el rendimiento del sistema Sysmex UF-1000i® en la detección de bacteriuria asintomática (BA) y la colonización por estreptococo grupo B (EGB) en la población gestante. MATERIAL Y MÉTODOS: Las orinas recibidas entre enero y julio de 2019 se analizaron mediante Sysmex UF-1000i® y paralelamente se cultivaron. Se recogieron variables demográficas, parámetros del citómetro y el resultado del urocultivo. El análisis del rendimiento del citómetro se realizó mediante curvas receiver operating characteristic (ROC) para la variable BACT/μL respecto a la detección de BA y EGB. RESULTADOS: De 33.687 muestras de orina recibidas, 1.443 (4,3%) correspondían a embarazadas. El urocultivo fue positivo en 82 (5,7%) muestras, 1.295 (89,7%) negativas y 66 (4,6%) contaminadas. El EGB se identificó en 69 (4,8%) gestantes, siendo el recuento inferior a 10E4 UFC/mL en 46 (66,7%) casos. Utilizando el punto de corte de 550 BACT/mL (sensibilidad, 91,5%; valor predictivo negativo, 99,3%) en la detección de la BA se evitaría sembrar el 74,1% de las muestras. Sin embargo, no se pudo establecer ningún punto de corte para EGB. CONCLUSIONES: Aunque Sysmex UF-1000i® es una herramienta válida para el cribado de BA en la mujer embarazada en nuestro medio, no es útil para detectar EGB; por lo que continúa siendo necesario realizar el urocultivo convencional en este subgrupo poblacional

OBJECTIVES: Nowadays, the use of flow-cytometry for the screening of urine samples is extended, but appropriate cut-off points for each population group are yet to be established. The objective of this study was to evaluate the Sysmex UF-1000i® cytometer as a screening method for detection of asymptomatic bacteriuria (AB) and Group B Streptococcus (GBS) in pregnant women. MATERIAL AND METHODS: Urine samples obtained during pregnancy between January-July 2019 were both processed with the Sysmex UF-1000i® and also cultured. Demographic data, flow-cytometry parameters and the result of the urine culture were collected. To assess the performance of the flow-cytometer for detection of AB and GBS, receiver operating characteristic (ROC) curves for the BACT/μL variable were applied. RESULTS: A total of 33,687 urine samples were received, among which 1,443 (4.3%) belonged to pregnant women. Urine culture was positive in 82 (5.7%) samples, 1,295 (89.7%) were negative and 66 (4.6%) were considered contaminated. GBS was isolated in 69 (4.8%) patients and 46 (66.7%) with a microbial count below 10E4 CFU/mL. For AB detection, the cut-off point of 550 BACT/μL yielded a sensitivity of 91.5%, a negative predictive value of 99.3% and could avoid culturing 74.1% of the samples. No cut-off value could be established for GBS detection. CONCLUSIONS: Although the Sysmex UF-1000i® system is a valid screening method for the AB detection in pregnant population, it is not useful for the identification of GBS bacteriuria in our area. Therefore, the conventional urine culture is still required during pregnancy

Discrepancia en la resistencia genotípica versus fenotípica a rifampicina en Mycobacterium tuberculosis. A propósito de un caso / Discrepancy in the genotypic versus phenotypic testing for resistance to rifampicin in Mycobacterium tuberculosis. A case report

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Lesiones máculo-papulosas diseminadas en paciente en contacto con ganado / Disseminated maculo-papular lesions in a patient in contact with cattle

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Corioamnionitis y sepsis neonatal causada por Eikenella corrodens / Chorioamnionitis and neonatal septicaemia due to Eikenella corrodens

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Meningitis neumocócica en Cantabria (España) en la era de las vacunas conjugadas antineumocócicas (2001-2015) / Pneumococcal meningitis in Cantabria (Spain) in the pneumococcal conjugate vaccine era (2001-2015)

Objetivo. Analizar las características de la meningitis neumocócica en < 14 años tras la comercialización de vacunas antineumocócicas conjugadas en nuestra comunidad. Métodos. Estudio retrospectivo de los casos de meningitis neumocócica en el que se analizaron dos períodos: pre vacuna antineumocócica trecevalente (VNC13v) (2001-2010) y post-VNC13v (2010-2015). Se recogieron datos demográficos y clínicos de los pacientes y datos microbiológicos. Resultados. Se diagnosticaron 18 casos. La incidencia media pre-VNC13v fue de 2,3/100 000, y disminuyó a 0,5/100 000 tras la VNC13v. Los serotipos más frecuentemente identificados fueron 6A y 10A (pre-VNC13v); 6B y 15B (post-VNC13v, solo dos casos). Trece de dieciocho pacientes ingresaron en la Unidad de Cuidados Intensivos. Todos los casos fueron tratados con cefotaxima y recibieron dexametasona 14/18. Seis pacientes sobrevivieron con secuelas y uno falleció. Conclusión. Se observa un importante descenso en la incidencia de meningitis neumocócica desde la comercialización de la VNC13v, por lo que cabe esperar que tras su introducción sistemática se produzca un descenso aún mayor.

Objective. To analyze the characteristics of pneumococcal meningitis in children < 14 years old following the market introduction of pneumococcal conjugate vaccines in our community. Methods. Retrospective study of pneumococcal meningitis cases with a two-period analysis: pre-13-valent pneumococcal conjugate vaccine (PCV13) (2001-2010) and post-PCV13 (2010-2015). Patient demographic and clinical data, and microbiological data were collected. Results. Eighteen cases were diagnosed. The mean incidence in the pre-PCV13 period was 2.3/100 000, which reduced to 0.5/100 000 after the PCV13 introduction. The most commonly identified serotypes were 6A and 10A (pre-PCV13); 6B and 15B (post-PCV13, only 2 cases). Out of 18 patients, 13 were admitted to the intensive care unit. All cases were treated with cefotaxime, and 14/18 received dexamethasone. Six patients survived with sequelae, and 1 died. Conclusion. A major reduction has been observed in the incidence of pneumococcal meningitis since the introduction of the PCV13 to the market, so an even greater reduction is expected following its systematic introduction.

Pneumococcal meningitis in Cantabria (Spain) in the pneumococcal conjugate vaccine era (2001-2015). / Meningitis neumocócica en Cantabria (España) en la era de las vacunas conjugadas antineumocócicas (2001-2015).

OBJECTIVE: To analyze the characteristics of pneumococcal meningitis in children ≤ 14 years old following the market introduction of pneumococcal conjugate vaccines in our community. METHODS: Retrospective study of pneumococcal meningitis cases with a two-period analysis: pre-13-valent pneumococcal conjugate vaccine (PCV13) (2001-2010) and post-PCV13 (2010-2015). Patient demographic and clinical data, and microbiological data were collected. RESULTS: Eighteen cases were diagnosed. The mean incidence in the pre-PCV13 period was 2.3/100 000, which reduced to 0.5/100 000 after the PCV13 introduction. The most commonly identified serotypes were 6A and 10A (pre-PCV13); 6B and 15B (post-PCV13, only 2 cases). Out of 18 patients, 13 were admitted to the intensive care unit. All cases were treated with cefotaxime, and 14/18 received dexamethasone. Six patients survived with sequelae, and 1 died. CONCLUSION: A major reduction has been observed in the incidence of pneumococcal meningitis since the introduction of the PCV13 to the market, so an even greater reduction is expected following its systematic introduction.

Analizar las características de la meningitis neumocócica en ≤ 14 años tras la comercialización de vacunas antineumocócicas conjugadas en nuestra comunidad.

Meningitis simultánea por neumococo y enterovirus en lactante / Simultaneous pneumococcal and enterovirus meningitis in an infant

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