Prospective, study comparing the accuracy of two different stool antigen tests (Premier Platinum HpSA and novel ImmunoCard STAT rapid test) for the diagnosis of Helicobacter pylori infection / Estudio prospectivo y comparativo entre la exactitud de 2 pruebas de antígenos en heces (Premier Platinum HpSA® y el nuevo test rápido ImmunoCard® STAT) para el diagnóstico de la infección por Helicobacter pylori

BACKGROUND: At present only monoclonal EIA (enzyme-immunoassay) stool antigen-tests have obtained optimal accuracy in the diagnosis of Helicobacter pylori. Our aim was to evaluate the accuracy of two stool antigen-tests, the validated Premier Platinum HpSA PLUS (EIA test) and the newly available ImmunoCard STAT! HpSA HD (rapid test) for the initial diagnosis and the confirmation of eradication of H. pylori infection. PATIENTS AND METHODS: Patients with indication of H. pylori diagnosis, or confirmation after treatment were included. Data were coded to protect personal data and ensure blindness between tests. Accuracy was considered as coincident diagnosis with the gold standard (13C-urea breath test, UBT). The EIA was used as a bench standard. All stool tests were performed in duplicate. RESULTS: 264 patients completed the protocol (100 naïve, 164 post-eradication). Average age was 52 years, 61% women, 11% ulcer. Positive diagnoses by UBT were 41% for naïve and 17% for post-eradication. Overall ImmunoCard and EIA accuracies were respectively 91% (95%C. I. =88-94%) and 89% (86-93%), sensitivities 72% (67-78%) and 72% (67-78%), and specificities 98% (96-100%), and 95% (92-97%). Concordance between ImmunoCard and EIA was 95% (93-98%). DISCUSSION: Our results indicate that the newly available ImmunoCard rapid stool antigen-test achieves 90% accuracy, with high specificity but suboptimal sensitivity. The ImmunoCard attained equivalent accuracies as the EIA bench standard, with 95% concordance

ANTECEDENTES: En la actualidad, únicamente los métodos de detección de antígenos en heces monoclonales basados en enzimoinmunoanálisis (ELISA) han obtenido una adecuada precisión para el diagnóstico de la infección por Helicobacter pylori. Nuestro objetivo fue evaluar la exactitud (sensibilidad y especificidad) de 2 métodos de antígenos en las heces, el previamente validado Premier Platinum HpSA® PLUS (ELISA) y el nuevo ImmunoCard® STAT! HpSA® HD (test rápido), para el diagnóstico inicial y la confirmación de la erradicación de la infección por H. pylori. PACIENTES Y MÉTODOS: Se incluyeron pacientes en los que estaba indicado el diagnóstico inicial de la infección por H. pylori o su confirmación tras el tratamiento. Los datos fueron codificados y los evaluadores de ambos test fueron ciegos para los resultados de las pruebas diagnósticas. El resultado principal fue la coincidencia con el resultado del patrón oro (prueba del aliento con 13C-urea). Los test en heces se realizaron por duplicado. RESULTADOS: Doscientos sesenta y cuatro pacientes completaron el protocolo (100 naïve, 164 posterradicación). La edad media fue de 52 años, el 61% fueron mujeres y el 11% tenían úlcera péptica. La prueba del aliento fue positiva en el 41% de los pacientes naïve y en el 17% posterradicación. La exactitud global del método rápido y del ELISA fue, respectivamente, 91% (IC 95%: 88-94%) y 89% (86-93%), la sensibilidad 72% (67-78%) y 72% (67-78%), y la especificidad 98% (96-100%) y 95% (92-97%). La concordancia entre el método ImmunoCard® y ELISA fue del 95% (93-98%). DISCUSIÓN: El nuevo método rápido de antígenos en heces (ImmunoCard® STAT! HpSA® HD) tiene una exactitud diagnóstica del 90%, con una elevada especificidad, pero una sensibilidad insuficiente. El método ImmunoCard® tiene una exactitud equivalente al método ELISA estándar, con una concordancia del 95%

Prospective, study comparing the accuracy of two different stool antigen tests (Premier Platinum HpSA and novel ImmunoCard STAT! rapid test) for the diagnosis of Helicobacter pylori infection.

BACKGROUND: At present only monoclonal EIA (enzyme-immunoassay) stool antigen-tests have obtained optimal accuracy in the diagnosis of Helicobacter pylori. Our aim was to evaluate the accuracy of two stool antigen-tests, the validated Premier Platinum HpSA PLUS (EIA test) and the newly available ImmunoCard STAT! HpSA HD (rapid test) for the initial diagnosis and the confirmation of eradication of H. pylori infection. PATIENTS AND METHODS: Patients with indication of H. pylori diagnosis, or confirmation after treatment were included. Data were coded to protect personal data and ensure blindness between tests. Accuracy was considered as coincident diagnosis with the gold standard (13C-urea breath test, UBT). The EIA was used as a bench standard. All stool tests were performed in duplicate. RESULTS: 264 patients completed the protocol (100 naïve, 164 post-eradication). Average age was 52 years, 61% women, 11% ulcer. Positive diagnoses by UBT were 41% for naïve and 17% for post-eradication. Overall ImmunoCard and EIA accuracies were respectively 91% (95%C.I.=88-94%) and 89% (86-93%), sensitivities 72% (67-78%) and 72% (67-78%), and specificities 98% (96-100%), and 95% (92-97%). Concordance between ImmunoCard and EIA was 95% (93-98%). DISCUSSION: Our results indicate that the newly available ImmunoCard rapid stool antigen-test achieves 90% accuracy, with high specificity but suboptimal sensitivity. The ImmunoCard attained equivalent accuracies as the EIA bench standard, with 95% concordance.

Antimicrobial susceptibility of 6 antimicrobial agents in Helicobacter pylori clinical isolates by using EUCAST breakpoints compared with previously used breakpoints / Sensibilidad de aislamientos clínicos de Helicobacter pylori a seis antimicrobianos utilizando los criterios EUCAST y comparando los resultados con criterios utilizados anteriormente

INTRODUCTION: The aim of this study was to determine the differences in percentage resistance in H. pylori clinical isolates using EUCAST breakpoints compared with previously used breakpoints. MIC value distribution in H. pylori clinical isolates was also studied. METHODS: Susceptibility to amoxicillin, tetracycline, metronidazole, clarithromycin, rifampicin and levofloxacin was performed by E-test in 824 H. pylori clinical isolates. EUCAST and previous breakpoints defined resistance as follows: MIC > 0.12 mg/L and ≥ 2 mg/L for amoxicillin, > 8 mg/L and ≥ 8 mg/L for metronidazole, > 0.5 mg/L and ≥ 1 mg/L for clarithromycin, >1mg/L and ≥ 32 mg/L for rifampicin, and > 1 mg/L and ≥ 4 mg/L for tetracycline and >1mg/L levofloxacin. RESULTS: Overall resistance rate by EUCAST and by previous breakpoints was 8.5% and 3.2% for amoxicillin, 0.6% and 0.1% for tetracycline, 39.2% and 39.7% for metronidazole, 51.2% and 51.2% for clarithromycin, 32% and 3.1% for rifampicin, and 6.7% and 6.7% for levofloxacin. CONCLUSIONS: When using the different breakpoints for antimicrobial susceptibility testing, similar results were found with most antibiotics tested (tetracycline, metronidazole, clarithromycin, and levofloxacin), except for amoxicillin and rifampicin

INTRODUCCIÓN: El objetivo de este estudio era determinar las diferencias en el porcentaje de resistencia de aislamientos clínicos de H. pylori usando los puntos de corte de EUCAST comparado con los puntos de corte usados anteriormente. También se estudió la distribución de los valores de CMI en los aislamientos de H. pylori. MÉTODOS: La sensibilidad de amoxicilina, tetraciclina, metronidazol, claritromicina, rifampicina y levo-floxacina se determinó mediante E-test en 824 aislamientos clínicos de H. pylori. Los puntos de corte utilizados fueron EUCAST: CMI > 0,12 mg/L para amoxicilina, > 8 mg/L para metronidazol, >0,5mg/L para claritromicina y > 1 mg/L para rifampicina, tetraciclina y levofloxacina. Los puntos de corte que se habían utilizado antes de EUCAST fueron: CMI ≥ 2 mg/L para amoxicilina, ≥ 8 mg/L para metronidazol, ≥ 1 mg/L para claritromicina, ≥ 32 mg/L para rifampicina, ≥ 4 mg/L para tetraciclina y > 1 mg/L para levofloxacina. RESULTADOS: La resistencia global con los puntos de corte EUCAST y con los puntos de corte anteriores fue: 8,5% y 3,2% para amoxicilina, 0,6% y 0,1% para tetraciclina, 39,2% y 39,7% para metronidazol, 51,2% y 51,2% para claritromicina, 32% y 3,1% para rifampicina y 6,7% y 6,7% para levofloxacina. CONCLUSIÓN: A pesar de la utilización de diferentes puntos de corte, se obtuvieron resultados de resistencia similares para la mayoría de los antibióticos probados (tetraciclina, metronidazol, claritrnnñomicina, y levofloxacino), con la única excepción de amoxicilina y rifampicina

Impact of the Microbiota and Gastric Disease Development by Helicobacter pylori.

Microorganisms in humans form complex communities with important functions and differences in each part of the body. The stomach was considered to be a sterile organ until the discovery of Helicobacter pylori, but nowadays, it is possible to demonstrate that other microorganisms beyond H. pylori can colonize the gastric mucosa and that the diverse microbiota ecosystem of the stomach is different from the mouth and the esophagus, and also from the small intestine and large intestine. H. pylori seems to be the most important member of the gastric microbiota with the highest relative abundance when present, but when it is absent, the stomach has a diverse microbiota. Proteobacteria, Firmicutes, Actinobacteria, Bacteroidetes, and Fusobacteria are the most abundant phyla in both H. pylori-positive and H. pylori-negative patients. The gastric commensal flora may play some role in the H. pylori-associated carcinogenicity, and differences in the gastric microbiota composition of patients with gastric cancer, intestinal metaplasia, and chronic gastritis are described. The gastric microbiota changed gradually from non-atrophic gastritis to intestinal metaplasia, and to gastric cancer (type intestinal).

Antimicrobial susceptibility of 6 antimicrobial agents in Helicobacter pylori clinical isolates by using EUCAST breakpoints compared with previously used breakpoints.

INTRODUCTION: The aim of this study was to determine the differences in percentage resistance in H. pylori clinical isolates using EUCAST breakpoints compared with previously used breakpoints. MIC value distribution in H. pylori clinical isolates was also studied. METHODS: Susceptibility to amoxicillin, tetracycline, metronidazole, clarithromycin, rifampicin and levofloxacin was performed by E-test in 824 H. pylori clinical isolates. EUCAST and previous breakpoints defined resistance as follows: MIC >0.12mg/L and ≥2mg/L for amoxicillin, >8mg/L and ≥8mg/L for metronidazole, >0.5mg/L and ≥1mg/L for clarithromycin, >1mg/L and ≥32mg/L for rifampicin, and >1mg/L and ≥4mg/L for tetracycline and >1mg/L levofloxacin. RESULTS: Overall resistance rate by EUCAST and by previous breakpoints was 8.5% and 3.2% for amoxicillin, 0.6% and 0.1% for tetracycline, 39.2% and 39.7% for metronidazole, 51.2% and 51.2% for clarithromycin, 32% and 3.1% for rifampicin, and 6.7% and 6.7% for levofloxacin. CONCLUSIONS: When using the different breakpoints for antimicrobial susceptibility testing, similar results were found with most antibiotics tested (tetracycline, metronidazole, clarithromycin, and levofloxacin), except for amoxicillin and rifampicin.

Detection of Helicobacter pylori and the genotypes of resistance to clarithromycin and the heterogeneous genotype to this antibiotic in biopsies obtained from symptomatic children.

The aim of this study was to use a commercially available kit (GenoType® HelicoDR; Hain Life Science, Germany) to detect Helicobacter pylori infection and clarithromycin resistance genotype in biopsies obtained from symptomatic children. RESULTS: 111 out of 136 (81.6%) biopsies were H. pylori positive by genotype: 47 (42.3%) showed wild-type genotype, 53 resistant genotype (47.7%) and 11 heterogeneous genotype (9.9%). Culture was negative in 27 out of the 111 genotyped biopsies. Mutation A2143G (87.5%), followed by A2142G (7.5%) and double mutant A2142C-A2143G (5%) were found. The 11 heterogeneous genotype biopsies showed wild-type plus A2143G in 9 and plus A2142G in 2. CONCLUSIONS: This kit is a rapid, culture-independent method for routine application in biopsies from the pediatric population that allows detection of clarithromycin resistance and heterogeneous genotypes. It is important to know the clinical impact of infection with this type of strains as well as the role in treatment success.

Characterization of the Gastric Microbiota in a Pediatric Population According to Helicobacter pylori Status.

BACKGROUND: Helicobacter pylori colonizes the human stomach of approximately 50% of the world's population, and increases the risk of several gastric diseases. The goal of this study is to compare the gastric microbiota in pediatric patients with and without H. pylori colonization. METHODS: We studied 51 children who underwent gastric endoscopy because of dyspeptic symptoms (18 H. pylori positive and 33 negative). Gastric biopsies were obtained for rapid urease test, culture, histology and DNA extraction. H. pylori was quantified by quantitative polymerase chain reaction and the gastric microbiome studied by V4-16S ribosomal RNA gene high-throughput sequencing. RESULTS: Bacterial richness and diversity of H. pylori-positive specimens were lower than those of negative, and both groups were clearly separated according to beta diversity. Taxonomic analysis confirmed that H. pylori-positive subjects had a higher relative abundance of Helicobacter genus (66.3%) than H. pylori-negative subjects (0.45%). Four phyla (proteobacteria, bacteroidetes, firmicutes and actinobacteria) accounted for >97% of all reads in both groups. Within proteobacteria, gamma- and betaproteobacteria were the most abundant for H. pylori-negative patients, whereas epsilonproteobacteria was for H. pylori positive. H. pylori-positive patients were associated with low body mass index. In the group of underweight patients (body mass index, <18.5), there were 46.1% of H. pylori-positive patients compared with 24% in the nonunderweight group (P = 0.049). Patients with active superficial gastritis in H. pylori-positive patients had the lowest alpha diversity (P = 0.035). CONCLUSIONS: We characterized the gastric microbiota for the first time in children with and without H. pylori and observed that when H. pylori is present, it tends to dominate the microbial community. In the H. pylori-negative patients, there was more relative abundance of gammaproteobacteria, betaproteobacteria, bacteroidia and clostridia classes and a higher bacterial richness and diversity.

Chryseobacterium spp., ¿nuevo patógeno oportunista asociado a fibrosis quística? / Chryseobacterium spp., a new opportunistic pathogen associated with cystic fibrosis?

INTRODUCCIÓN: En los últimos años se ha incrementado el aislamiento de bacilos gramnegativos no fermentadores en los pacientes con fibrosis quística (FQ). En el presente trabajo se registra la frecuencia de aislamientos de Chryseobacterium spp., analizándose sus características, patrones de resistencia y evolución clínica de los pacientes con FQ de nuestra unidad. MÉTODOS: Se recogieron todos los aislamientos respiratorios de Chryseobacterium spp. de los pacientes atendidos en la unidad de FQ del Hospital de la Princesa durante 3años (marzo 2009-marzo 2012). Para su identificación fenotípica y genotípica y para el estudio de sensibilidad se empleó metodología convencional. Para la valoración de la función pulmonar de los pacientes se tuvo en cuenta el volumen espirado forzado en el primer segundo (FEV1) y los resultados se analizaron con el paquete estadístico SPSS. RESULTADOS: Se constató un aumento en la incidencia de Chryseobacterium spp., obteniéndose 17 aislamientos pertenecientes a 9 pacientes. Tres enfermos presentaron colonización crónica por este microorganismo y uno de ellos mostró un deterioro significativo de la función pulmonar. En 7 de los pacientes existió co-colonización con Staphylococcus aureus, y con Pseudomonas aeruginosa en 4 de ellos. CONCLUSIÓN: Chryseobacterium spp. debe ser considerado como un nuevo patógeno oportunista emergente en pacientes con FQ. Es imprescindible una vigilancia microbiológica y clínica de este grupo de pacientes para detectar la colonización por Chryseobacterium spp. y poder evitar la infección crónica. En estas circunstancias, y aunque se desconoce su implicación clínica, se debe valorar su posible erradicación, siendo el cotrimoxazol la mejor opción terapéutica

INTRODUCTION: There is an increase in the isolation of non-fermenting gramnegative bacilli in patients with cystic fibrosis (CF). The present study evaluates the frequency of isolates of Chryseobacterium spp., analyzing its characteristics, resistance patterns and clinical outcome of patients. METHODS: It has been collected all respiratory isolates of Chryseobacterium spp. of patients attended in the CF unit of Hospital de la Princesa for three years (march 2009-march 2012). For phenotypic and genotypic identification and sensitivity study conventional methodology was used. For the assessment of the patients lung function was considered the forced expiratory volume in one second (FEV1) and the results were analyzed with SPSS. RESULTS: There was an increase in the incidence of Chryseobacterium spp. with 17 isolates from 9 patients. Three patients had chronic colonization by this microorganism and one showed significant impairment of lung function. Seven patients showed also colonization with Staphylococcus aureus and 4 of them with Pseudomonas aeruginosa. CONCLUSION: Chryseobacterium spp. should be considered as a new emerging opportunistic pathogen in patients with CF. It is essential the clinical and microbiological monitoring of this group of patients for detection of Chryseobacterium spp. colonization and to prevent the chronic infection. In these circumstances it must assess its possible eradication, though its clinical impact is unknown. Cotrimoxazole being the best treatment option

[Chryseobacterium spp., a new opportunistic pathogen associated with cystic fibrosis?]. / Chryseobacterium spp., ¿nuevo patógeno oportunista asociado a fibrosis quística?

INTRODUCTION: There is an increase in the isolation of non-fermenting gramnegative bacilli in patients with cystic fibrosis (CF). The present study evaluates the frequency of isolates of Chryseobacterium spp., analyzing its characteristics, resistance patterns and clinical outcome of patients. METHODS: It has been collected all respiratory isolates of Chryseobacterium spp. of patients attended in the CF unit of Hospital de la Princesa for three years (march 2009-march 2012). For phenotypic and genotypic identification and sensitivity study conventional methodology was used. For the assessment of the patients lung function was considered the forced expiratory volume in one second (FEV1) and the results were analyzed with SPSS. RESULTS: There was an increase in the incidence of Chryseobacterium spp. with 17 isolates from 9 patients. Three patients had chronic colonization by this microorganism and one showed significant impairment of lung function. Seven patients showed also colonization with Staphylococcus aureus and 4 of them with Pseudomonas aeruginosa. CONCLUSION: Chryseobacterium spp. should be considered as a new emerging opportunistic pathogen in patients with CF. It is essential the clinical and microbiological monitoring of this group of patients for detection of Chryseobacterium spp. colonization and to prevent the chronic infection. In these circumstances it must assess its possible eradication, though its clinical impact is unknown. Cotrimoxazole being the best treatment option.