RESUMEN
BACKGROUND: Clostridium difficile infection (CDI) caused by ribotype 002 strain is associated with poor outcomes in Chinese patients. Fecal microbiota transplantation (FMT) is an effective but costly treatment for CDI. We aimed to examine potential cost-effectiveness of ribotype-guided FMT in Chinese patients with severe CDI. METHODS: A decision-analytic model was designed to simulate outcomes of ribotype 002-guided FMT versus vancomycin treatment in Chinese patients with severe CDI in the hospital setting. Outcome measures included mortality rate; direct medical cost; and quality-adjusted life year (QALY) loss for CDI. Sensitivity analysis was performed to examine robustness of base-case results. RESULTS: Comparing to vancomycin treatment, ribotype-guided FMT group reduced mortality (11.6% versus 17.1%), cost (USD8,807 versus USD9,790), and saved 0.472 QALYs in base-case analysis. One-way sensitivity analysis found the ribotype-guided FMT group to remain cost-effective when patient acceptance rate of FMT was >0.6% and ribotype 002 prevalence was >0.07%. In probabilistic sensitivity analysis, ribotype-guided FMT gained higher QALYs at 100% of simulations with mean QALY gain of 0.405 QALYs (95%CI: 0.400-0.410; p<0.001). The ribotype-guided group was less costly in 97.9% of time, and mean cost-saving was USA679 (95%CI: 670-688; p<0.001). CONCLUSIONS: In the present model, ribotype-guided FMT appears to be a potential option to save QALYs and cost when comparing with vancomycin. The cost-effectiveness of ribotype-guided FMT is subject to the patient acceptance to FMT and prevalence of ribotype 002.
Asunto(s)
Clostridioides difficile/genética , Infecciones por Clostridium/terapia , Enterocolitis Seudomembranosa/terapia , Trasplante de Microbiota Fecal/economía , Trasplante de Microbiota Fecal/métodos , Ribotipificación , Anciano , Anciano de 80 o más Años , Antibacterianos/uso terapéutico , Pueblo Asiatico , China/epidemiología , Clostridioides difficile/clasificación , Infecciones por Clostridium/economía , Infecciones por Clostridium/epidemiología , Análisis Costo-Beneficio , Técnicas de Apoyo para la Decisión , Enterocolitis Seudomembranosa/economía , Enterocolitis Seudomembranosa/epidemiología , Trasplante de Microbiota Fecal/estadística & datos numéricos , Femenino , Frecuencia de los Genes , Humanos , Masculino , Persona de Mediana Edad , Ribotipificación/economía , Ribotipificación/métodos , Índice de Severidad de la Enfermedad , Tasa de Supervivencia , Resultado del Tratamiento , Vancomicina/uso terapéuticoRESUMEN
Clostridium difficile strains were typed by a newly developed MALDI-TOF method, high molecular weight typing, and compared to PCR ribotyping. Among 500 isolates representing 59 PCR ribotypes a total of 35 high molecular weight types could be resolved. Although less discriminatory than PCR ribotyping, the method is extremely fast and simple, and supports for cost-effective screening of isolates during outbreak situations.
Asunto(s)
Técnicas de Tipificación Bacteriana/métodos , Clostridioides difficile/química , Infecciones por Clostridium/microbiología , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos , Técnicas de Tipificación Bacteriana/economía , Clostridioides difficile/genética , Clostridioides difficile/aislamiento & purificación , Infecciones por Clostridium/diagnóstico , Humanos , Peso Molecular , Reacción en Cadena de la Polimerasa/métodos , Ribotipificación/economía , Ribotipificación/métodos , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/economíaRESUMEN
PCR targeting the gene encoding 16S ribosomal RNA (commonly named broad-range PCR or 16S PCR) has been used for 20 years as a polyvalent tool to study prokaryotes. Broad-range PCR was first used as a taxonomic tool, then in clinical microbiology. We will describe the use of broad-range PCR in clinical microbiology. The first application was identification of bacterial strains obtained by culture but whose phenotypic or proteomic identification remained difficult or impossible. This changed bacterial taxonomy and allowed discovering many new species. The second application of broad-range PCR in clinical microbiology is the detection of bacterial DNA from clinical samples; we will review the clinical settings in which the technique proved useful (such as endocarditis) and those in which it did not (such as characterization of bacteria in ascites, in cirrhotic patients). This technique allowed identifying the etiological agents for several diseases, such as Whipple disease. This review is a synthesis of data concerning the applications, assets, and drawbacks of broad-range PCR in clinical microbiology.
Asunto(s)
Bacteriología/tendencias , Reacción en Cadena de la Polimerasa/métodos , Ribotipificación/métodos , Bacterias/clasificación , Bacterias/genética , Bacterias/aislamiento & purificación , Infecciones Bacterianas/diagnóstico , Infecciones Bacterianas/microbiología , ADN Bacteriano/genética , ADN Ribosómico/genética , Reacciones Falso Positivas , Predicción , Humanos , Espectrometría de Masas , Reacción en Cadena de la Polimerasa/economía , Reacción en Cadena de la Polimerasa/tendencias , ARN Bacteriano/genética , ARN Ribosómico 16S/genética , Ribotipificación/economía , Ribotipificación/tendencias , Sensibilidad y Especificidad , Especificidad de la EspecieRESUMEN
Two DNA-based methods were compared for the ability to assign serotype to 139 isolates of Salmonella enterica ssp. I. Intergenic sequence ribotyping (ISR) evaluated single nucleotide polymorphisms occurring in a 5S ribosomal gene region and flanking sequences bordering the gene dkgB. A DNA microarray hybridization method that assessed the presence and the absence of sets of genes was the second method. Serotype was assigned for 128 (92.1%) of submissions by the two DNA methods. ISR detected mixtures of serotypes within single colonies and it cost substantially less than Kauffmann-White serotyping and DNA microarray hybridization. Decreasing the cost of serotyping S. enterica while maintaining reliability may encourage routine testing and research.
Asunto(s)
Análisis por Micromatrices/métodos , Ribotipificación/métodos , Salmonella enterica/clasificación , Salmonella enterica/genética , Animales , ADN Bacteriano/genética , ADN Intergénico , Humanos , Análisis por Micromatrices/economía , Análisis de Secuencia por Matrices de Oligonucleótidos , Ribotipificación/economía , Infecciones por Salmonella/microbiología , Salmonelosis Animal/microbiología , Serotipificación/economía , Serotipificación/métodos , Deshidrogenasas del Alcohol de Azúcar/genéticaRESUMEN
In order to identify the agent responsible of the infectious process and understanding the pathogenic/pathological implications, clinical course, and to implement an effective antimicrobial therapy, a mainstay in the practice of clinical microbiology is the allocation of species to a microbial isolation. In daily routine practice microbiology laboratory phenotypic techniques are applied to achieve this goal. However, they have some limitations that are seen more clearly for some kinds of microorganism. Molecular methods can circumvent some of these limitations, although its implementation is not universal. This is due to higher costs and the level of expertise required for thei implementation, so molecular methods are often centralized in reference laboratories and centers. Recently, proteomics-based methods made an important breakthrough in the field of diagnostic microbiology and will undoubtedly have a major impact on the future organization of the microbiology services. This paper is a short review of the most noteworthy aspects of the three bacterial identification methods described above used in microbiology laboratories.
Asunto(s)
Técnicas de Tipificación Bacteriana/métodos , Automatización , Bacterias/clasificación , Bacterias/aislamiento & purificación , Infecciones Bacterianas/microbiología , Proteínas Bacterianas/análisis , Técnicas de Tipificación Bacteriana/economía , Técnicas de Tipificación Bacteriana/instrumentación , Técnicas de Tipificación Bacteriana/estadística & datos numéricos , ADN Bacteriano/análisis , Humanos , Laboratorios/economía , Microbiología , Técnicas de Diagnóstico Molecular/economía , Técnicas de Diagnóstico Molecular/estadística & datos numéricos , Fenotipo , Proteómica , Ribotipificación/economía , Ribotipificación/métodos , Ribotipificación/estadística & datos numéricos , España , Espectrometría de Masa por Láser de Matriz Asistida de Ionización DesorciónRESUMEN
Various biopsy-based methods for the detection of Helicobacter pylori are evaluated to determine their sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV), followed by polymerase chain reaction (PCR) for the 16S ribosomal RNA (rRNA) gene of H. pylori (16S PCR) to confirm the results. Seventyfive patients (65% [49] males, age range: 17-77 years, mean 42+/-14.6 years) with dyspeptic symptoms are included in the study. Gastric antrum biopsy specimens collected during endoscopy are tested using a urea agar base enriched with 40% urea solution (eUAB, Oxoid)), a commercial rapid urease test (Pronto Dry, Medical Instrument Corp, Switzerland), histopathology and 16S PCR. The eUAB test showed 97% sensitivity, 86% specificity, 84% PPV, 97% NPV and 91% accuracy when the diagnosis of H. pylori infection was made with positive Pronto Dry and histopathology. Pronto Dry showed 100% sensitivity, 82% specificity, 80% PPV, 100% NPV and 89% accuracy when the diagnosis of H. pylori infection was made on positive histopathology and eUAB. Thus, the eUAB can be used as a rapid urease test. It is economical and has a sensitivity and specificity comparable to a commercially available rapid urease test to detect urease activity of H. pylori in gastric biopsy.
Asunto(s)
Países en Desarrollo , Mucosa Gástrica/enzimología , Infecciones por Helicobacter/diagnóstico , Helicobacter pylori/aislamiento & purificación , Costos y Análisis de Costo , Mucosa Gástrica/microbiología , Mucosa Gástrica/patología , Gastroscopía/economía , Humanos , Pakistán , Juego de Reactivos para Diagnóstico , Ribotipificación/economía , Sensibilidad y Especificidad , Ureasa/análisisRESUMEN
The clinical profile of nontuberculous mycobacteria (NTM) has been raised by the human immunodeficiency virus and AIDS pandemic. Different laboratory techniques, often molecular based, are available to facilitate the rapid and accurate identification of NTM. The expense of these advanced techniques has been questioned. At the National Reference Center for Mycobacteriology and the Health Sciences Center, University of Manitoba, in Winnipeg, Canada, we performed a direct cost analysis of laboratory techniques for commercial DNA probe-negative (Gen-Probe, Inc., San Diego, Calif.), difficult-to-identify NTM. We compared the costs associated with conventional phenotypic methodology (biochemical testing, pigment production, growth, and colony characteristics) and genotypic methodology (16S ribosomal DNA [rDNA] sequence-based identification). We revealed a higher cost per sample with conventional methods, and this cost varied with organism characteristics: $80.93 for slowly growing, biochemically active NTM; $173.23 for slowly growing, biochemically inert NTM; and $129.40 for rapidly growing NTM. The cost per sample using 16S rDNA sequencing was $47.91 irrespective of organism characteristics, less than one-third of the expense associated with phenotypic identification of biochemically inert, slow growers. Starting with a pure culture, the turnaround time to species identification is 1 to 2 days for 16S rDNA sequencing compared to 2 to 6 weeks for biochemical testing. The accuracy of results comparing both methodologies is briefly discussed. 16S rDNA sequencing provides a cost-effective alternative in the identification of clinically relevant forms of probe-negative NTM. This concept is not only useful in mycobacteriology but also is highly applicable in other areas of clinical microbiology.