Direct Urine Resistance Detection Using VITEK 2.

Urinary tract infections (UTIs) are the most common infectious diseases in both communities and hospitals. With non-anatomical or functional abnormalities, UTIs are usually self-limiting, though women suffer more reinfections throughout their lives. Certainly, antibiotic treatment leads to a more rapid resolution of symptoms, but also it selects resistant uropathogens and adversely affects the gut and vaginal microbiota. As uropathogens are increasingly becoming resistant to currently available antibiotics, it could be time to explore alternative strategies for managing UTIs. Rapid identification and antimicrobial susceptibility testing (AST) allow fast and precise treatment. The objective of this study was to shorten the time of diagnosis of UTIs by combining pathogen screening through flow cytometry, microbial identification by matrix-assisted laser desorption ionisation time-of-flight mass spectrometry (MALDI-TOF MS), and the VITEK 2 system for the direct analysis of urine samples. First, we selected positive urine samples by flow cytometry using UF5000, establishing the cut-off for positive at 150 bacteria/mL. After confirming the identification using MALDI-TOF MS and filtering the urine samples for Escherichia coli, we directly tested the AST N388 card using VITEK 2. We tested a total of 211 E. coli from urine samples. Cefoxitin, ertapenem, imipenem, gentamicin, nalidixic acid, ciprofloxacin, fosfomycin, and nitrofurantoin had no major important errors (MIE), and ampicillin, cefuroxime, and tobramycin showed higher MIEs. Cefepime, imipenem, and tobramycin had no major errors (ME). Fosfomycin was the antibiotic with the most MEs. The antibiotic with the most minor errors (mE) was ceftazidime. The total categorical agreement (CA) was 97.4% with a 95% CI of (96.8-97.9)95%. The direct AST from the urine samples proposed here was shorter by one day, without significant loss of sensibility regarding the standard diagnosis. Therefore, we hypothesize that this method is more realistic and better suited to human antibiotic concentrations.

EMBRACE-WATERS statement: Recommendations for reporting of studies on antimicrobial resistance in wastewater and related aquatic environments.

BACKGROUND: A One Health approach requires integrative research to elucidate antimicrobial resistance (AMR) in the environment and the risks it poses to human health. Research on this topic involves experts from diverse backgrounds and professions. Shortcomings exist in terms of consistent, complete, and transparent reporting in many environmental studies. Standardized reporting will improve the quality of scientific papers, enable meta-analyses and enhance the communication among different experts. In this study, we aimed to generate a consensus of reporting standards for AMR research in wastewater and related aquatic environments. METHODS: Based on a risk of bias assessment of the literature in a systematic review, we proposed a set of study quality indicators. We then used a multistep modified Delphi consensus to develop the EMBRACE-WATERS statement (rEporting antiMicroBial ResistAnCE in WATERS), a checklist of recommendations for reporting in studies of AMR in wastewater and related aquatic environments. FINDINGS: Consensus was achieved among a multidisciplinary panel of twenty-one experts in three steps. The developed EMBRACE-WATERS statement incorporates 21 items. Each item contains essential elements of high-quality reporting and is followed by an explanation of their rationale and a reporting-example. The EMBRACE-WATERS statement is primarily intended to be used by investigators to ensure transparent and comprehensive reporting of their studies. It can also guide peer-reviewers and editors in evaluation of manuscripts on AMR in the aquatic environment. This statement is not intended to be used to guide investigators on the methodology of their research. INTERPRETATION: We are hopeful that this statement will improve the reporting quality of future studies of AMR in wastewater and related aquatic environments. Its uptake would generate a common language to be used among researchers from different disciplines, thus advancing the One Health approach towards understanding AMR spread across aquatic environments. Similar initiatives are needed in other areas of One Health research.

Application and Perspectives of MALDI-TOF Mass Spectrometry in Clinical Microbiology Laboratories.

Early diagnosis of severe infections requires of a rapid and reliable diagnosis to initiate appropriate treatment, while avoiding unnecessary antimicrobial use and reducing associated morbidities and healthcare costs. It is a fact that conventional methods usually require more than 24-48 h to culture and profile bacterial species. Mass spectrometry (MS) is an analytical technique that has emerged as a powerful tool in clinical microbiology for identifying peptides and proteins, which makes it a promising tool for microbial identification. Matrix assisted laser desorption ionization-time of flight MS (MALDI-TOF MS) offers a cost- and time-effective alternative to conventional methods, such as bacterial culture and even 16S rRNA gene sequencing, for identifying viruses, bacteria and fungi and detecting virulence factors and mechanisms of resistance. This review provides an overview of the potential applications and perspectives of MS in clinical microbiology laboratories and proposes its use as a first-line method for microbial identification and diagnosis.

A multicentre study investigating parameters which influence direct bacterial identification from urine.

Rapid diagnosis is one of the best ways to improve patient management and prognosis as well as to combat the development of bacterial resistance. The aim of this study was to study parameters that impact the achievement of reliable identification using a combination of flow cytometry and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-ToF-MS).The study was carried out in nine hospitals in Spain and included 1,050 urine samples with bacterial counts of 5x106 bacteria/ml. MALDI-ToF-MS-based identification was performed according to a previously described protocol. Valid identification by direct MALDI-ToF-MS was obtained in 72.8% of samples, in 80.3% of samples found to be positive by culture, 32.2% of contaminated samples, and 19.7% of negative samples. Among the positives samples with a valid identification the concordance at the species level was 97.2%. The parameters related to success of direct identification were: high bacterial count, the presence of Escherichia coli as a pathogen and rod-bacteria morphology provided by flow cytometry. The parameters related to failure were a high epithelial cell (EC) count, a high white blood cell (WBC) count and urine samples obtained from in-patients. In summary, this multicentre study confirms previously published data on the usefulness and accuracy of direct MALDI-ToF-MS-based identification of bacteria from urine samples. It seems important to evaluate not only the bacterial count, but also other parameters, such as EC and WBC counts, bacterial species and morphology, and the health care setting, to decide whether the sample is suitable for direct identification.

[Plasmid-mediated AMPc producing Proteus mirabilis in the Health Care Area of Santiago de Compostela: molecular and epidemiological analysis by rep-PCR and MALDI-TOF]. / Proteus mirabilis productor de AmpC plasmídica en el Área Sanitaria de Santiago de Compostela: prevalencia y caracterización molecular por rep-PCR y MALDI-TOF MS.

INTRODUCTION: Proteus mirabilis is an important pathogen isolated from both community-acquired and health-care associated infections. Acquired AmpC-type beta-lactamases represent an important mechanism of resistance to extended-spectrum cephalosporins and are emerging in several European countries. The objective of this work was to know the prevalence of acquired AmpC beta-lactamase producing P. mirabilis over the last three years and eight months and their clonal relationships comparing MALDI-TOF and automated rep-PCR results. METHODS: P. mirabilis isolates (n= 1,396) were obtained from routine cultures at the University Hospital Complex of Santiago de Compostela from January 2006 to August 2009. Identification to the species level and antimicrobial susceptibility testing were achieved with Vitek 2. The isolates showing intermediate or total resistance to amoxicillin-clavulanic and cefoxitin, cefotaxime or ceftazidime were selected for AmpC phenotypic detection by double-disk synergy test, and molecular confirmation by multiplex PCR. Molecular typing of the isolates was performed by automated rep-PCR and MALDI-TOF. RESULTS: For the last three years and eight months, the prevalence of AmpC-producing P. mirabilis increased from 0.17% to 4.5%, mainly associated with urinary tract infection in elderly outpatients. In all cases, plasmidic AmpC belonging to LAT/CMY lineage were detected. A high genetic variability was seen with both, rep-PCR and MALDI-TOF MS. CONCLUSIONS: AmpC-producing P. mirabilis is an emergent pathogen. The high genetic variability detected suggests that the spread of the resistance mechanism is more probable than a clone dispersion. Automated rep-PCR and MALDI-TOF MS show as fast and decisive methods for bacterial strain typing in clinical microbiology laboratories.

Proteus mirabilis productor de AmpC plasmídica en el Área Sanitaria de Santiago de Compostela: prevalencia y caracterización molecular por rep-PCR y MALDI-TOF MS / Plasmid-mediated AMPc producing Proteus mirabilis in the Health Care Area of Santiago de Compostela: molecular and epidemiological analysis by rep-PCR and MALDI-TOF

Introducción: Proteus mirabilis es un patógeno de importancia creciente tanto en las infecciones nosocomiales como en las comunitarias. La producción de AmpC plasmídica es un mecanismo de resistencia frente a cefalosporinas de espectro extendido emergente en esta bacteria por lo que se consideró de gran interés estudiar su prevalencia en nuestro Área Sanitaria así como su variabilidad genética, comparando dos métodos recientemente incorporados al mercado: MALDI-TOF y rep-PCR automatizada. Métodos: Entre enero de 2006 y agosto de 2009 se recuperaron 1.396 aislamientos de P. mirabilis a partir de los cultivos de rutina realizados en Complejo Hospitalario Universitario de Santiago de Compostela. La identificación y el antibiograma se hicieron por Vitek 2. Aquellos aislamientos con sensibilidad reducida a amoxicilina-clavulánico y a cefoxitina, cefotaxima o ceftazidima fueron seleccionados para la detección fenotípica y genotípica de AmpC plasmídica mediante sinergia con doble disco y PCR múltiple, respectivamente. La tipificación molecular se llevó a cabo, comparativamente, mediante rep-PCR automatizada y MALDI-TOF. Resultados: A lo largo de tres años y ocho meses, la prevalencia de P. mirabilis productor de AmpC pasó del 0,17% al 4,5%, mayoritariamente asociado a infección urinaria en pacientes ancianos no hospitalizados. En todos los casos, AmpC plasmídica perteneció a la familia LAT/CMY. Se observó una gran variabilidad genética entre los aislamientos tanto por rep-PCR (DiversiLab) como por MALDI-TOF MS. Conclusión: P. mirabilis productor de AmpC adquirida es un patógeno emergente. La variabilidad genética de las cepas estudiadas apunta a una dispersión de este mecanismo de resistencia más que a una diseminación clonal. Rep-PCR automatizada y MALDI-TOF se muestran como métodos rápidos y resolutivos para la tipificación molecular en los laboratorios de microbiología clínica(AU)

Introduction: Proteus mirabilis is an important pathogen isolated from both community-acquired and health-care associated infections. Acquired AmpC-type beta-lactamases represent an important mechanism of resistance to extended-spectrum cephalosporins and are emerging in several European countries. The objective of this work was to know the prevalence of acquired AmpC beta-lactamase producing P. mirabilis over the last three years and eight months and their clonal relationships comparing MALDI-TOF and automated rep-PCR results. Methods: P. mirabilis isolates (n= 1,396) were obtained from routine cultures at the University Hospital Complex of Santiago de Compostela from January 2006 to August 2009. Identification to the species level and antimicrobial susceptibility testing were achieved with Vitek 2. The isolates showing intermediate or total resistance to amoxicillin-clavulanic and cefoxitin, cefotaxime or ceftazidime were selected for AmpC phenotypic detection by double-disk synergy test, and molecular confirmation by multiplex PCR. Molecular typing of the isolates was performed by automated rep-PCR and MALDI-TOF. Results: For the last three years and eight months, the prevalence of AmpC-producing P. mirabilis increased from 0.17% to 4.5%, mainly associated with urinary tract infection in elderly outpatients. In all cases, plasmidic AmpC belonging to LAT/CMY lineage were detected. A high genetic variability was seen with both, rep-PCR and MALDI-TOF MS. Conclusions: AmpC-producing P. mirabilis is an emergent pathogen. The high genetic variability detected suggests that the spread of the resistance mechanism is more probable than a clone dispersion. Automated rep-PCR and MALDI-TOF MS show as fast and decisive methods for bacterial strain typing in clinical microbiology laboratories(AU)

Susceptibility trends of Bacteroides fragilis group and characterisation of carbapenemase-producing strains by automated REP-PCR and MALDI TOF.

Susceptibility testing of clinical isolates of anaerobic bacteria is not considered, often, mandatory in routine clinical practice and the treatments are empirically established. Thus, periodic monitoring of the susceptibility patterns of anaerobic bacteria is advisable. The aim of this study was to update on resistance of Bacteroides fragilis group in our Institution with special attention to carbapenems reporting metallo-beta-lactamase producing strains for the first time in Spain, and to compare fingerprinting analysis results obtained by using automated rep-PCR (DiversiLab System) and MALDI-TOF MS. A total of 830 non-duplicated clinical isolates of the B. fragilis group recovered from the years 2006 to 2010 were studied. B. fragilis was the most prevalent species (59.5%). The total susceptibility of B. fragilis group isolates were: penicillin, 13.3%; amoxicillin/clavulanic, 89.6%; piperacillin-tazobactam, 91.8%; cefoxitin, 65.8%; ertapenem, 95.9%; imipenem, 98.2%; clindamycin, 53.4% and metronidazole, 96.4%. The percentage of sensitive isolates did not change significantly over time for amoxicillin/clavulanic, cefoxitin, clindamycin and metronidazole. A slight increase in the rate of resistance to ertapenem and imipenem was observed. Imipenem resistance and carbapenemase production were detected for the first time in our laboratory in the year 2007. No other report of carbapenemase-producing B. fragilis in our country has been previously published. Six imipenem-resistant isolates were MBL-producing and PCR positive for cfiA gene. Four of them were PCR positive for IS-like immediately upstream cfiA gene and two of them were negative. Both, automated rep-PCR (DiversiLab) and MALDI-TOF MS, revealed a great genetic diversity among carbapenem-producing strains suggesting the acquisition of novel resistance genes more than clonal dissemination of them. Both methods seem to be useful tools for fast and accurate identification and strain typing of B. fragilis group in the daily laboratory routine. Because of the relevant increase observed in Bacteroides species isolated from blood cultures and the appearance of carbapenemase-producing strains in our Institution, we recommend to test the antimicrobial susceptibility of the isolates, at least in the most severe patients.

Molecular and epidemiological analysis of nosocomial carbapenem-resistant Klebsiella spp. using repetitive extragenic palindromic-polymerase chain reaction and matrix-assisted laser desorption/ionization-time of flight.

INTRODUCTION: Infections with carbapenem-resistant enterobacteria are an emerging threat. This study reports the microbiologic, clinical, and epidemiologic features and the therapeutic outcomes of the infections caused by carbapenem- and pandrug-resistant Klebsiella emerged in our hospital. Fingerprinting analyses by automated repetitive extragenic palindromic-polymerase chain reaction (rep-PCR) and matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry are also compared. MATERIALS AND METHODS: Carbapenem-resistant Klebsiella spp. affecting 13 patients were investigated using automated rep-PCR (DiversiLab System) and MALDI-TOF. Species identification was performed by Vitek 2 System and MALDI-TOF. Antimicrobial susceptibility testing was made using Vitek 2 System and Etest. Screening for extended spectrum beta-lactamase (ESBL) and carbapenemase production was made by double disk synergy and Hodge tests, respectively. Synergy studies were performed using Etest. DNA array was used for detection of KPC and ESBLs. bla(VIM-1) gene was amplified by PCR and sequencing. Use of carbapenems in the hospital was studied. RESULTS: A total of 13 patients were found to be colonized/infected with carbapenem-resistant Klebsiella. All patients were previously submitted to surgery and/or presented with severe underlying disease. After carbapenem-resistant Klebsiella isolation, the majority of the patients were treated with amikacin plus carbapenem, tigecycline, or fosfomycin. All Klebsiella isolates (n = 14), except two, had the bla(VIM-1) gene and all Klebsiella pneumoniae also had bla(SHV) gene associated with ESBL production. DiversiLab system showed higher discriminatory power than MALDI-TOF for strain typing. CONCLUSIONS: The risk of a rapid dissemination and the persistence of these multidrug-resistant strains through the time determine the need to implement routine procedures for metallo-beta-lactamase detection and measures for prevention of the spread of these microorganisms. The combined use of MALDI-TOF for species identification and DiversiLab System for clonal strain typing may be a useful tool for fast and accurate management of nosocomial outbreaks. The potential clinical utility of fosfomycin in this matter should be considered in future studies.

Comparación entre las pruebas para la detección de betalactamasas de espectro extendido de los sistemas Vitek 2 y Phoenix / Comparative assessment of the Vitek 2 and Phoenix systems for detection of extended-spectrum beta-lactamases

Introducción La detección de la multirresistencia a betalactámicos en Escherichia coli y Klebsiella pneumoniae es una cuestión clínicamente relevante. Por otro lado, es interesante diferenciar entre la producción de betalactamasas de espectro extendido (BLEE) y otros mecanismos de resistencia para evitar el tratamiento inadecuado de infecciones causadas por este tipo de cepas. El objetivo del presente estudio fue comparar la capacidad de las pruebas confirmatorias de los sistemas automatizados Vitek 2 y Phoenix para detectar la producción de BLEE en E. coli y K. pneumoniae. Material y métodos Se ensayaron 193 aislamientos clínicos fenotípicamente productores de BLEE (174 E. coli y 19K. pneumoniae) por Vitek 2 y BD Phoenix System y se utilizaron las tarjetas AST-N058 y los paneles UNMIC/ID-62, respectivamente. Se consideraron métodos fenotípicos de referencia la prueba de sinergia con doble disco y Etest. Como controles positivos y negativos se ensayaron 12 cepas genotípicamente caracterizadas. Resultados En el caso de los aislamientos clínicos, la sensibilidad fue del 99,5% para Vitek 2 y del 95,3% para Phoenix. En las cepas control no hubo diferencias entre ambos sistemas. La ejecución del sistema experto elevó la sensibilidad del Phoenix al 100%. Sin embargo, el sistema experto de Vitek 2 consideró incoherentes los resultados obtenidos en 7 aislamientos con la prueba para BLEE positiva. Conclusión La sensibilidad de la prueba confirmatoria para la producción de BLEE es superior en las tarjetas N-058 de Vitek. No obstante, la actuación de los sistemas expertos sitúa a ambos sistemas a la misma altura en su capacidad de detección de BLEE en E. coli y K. pneumoniae (AU)

Introduction and Purpose Detection of beta-lactam resistance in Escherichia coli and Klebsiella pneumoniae strains is clinically relevant. Moreover, it is important to differentiate between extended-spectrum beta-lactamase (ESBL) production and other mechanisms of resistance to avoid inadequate treatment of infection caused by these strains. The aim of this study was to compare the performance of the Vitek 2 and BD Phoenix automated systems for confirmatory testing of ESBL production. Material and Methods A total of 193 clinical isolates of phenotypically confirmed ESBL producers (174 E. coli and 19 K. pneumoniae) were assayed by the Vitek 2 and BD Phoenix systems using AST-N058 cards and UNMIC/ID-62 panels, respectively. The double-disk synergy test and the Etest were used as phenotype reference methods. Twelve strains characterized by genotyping were used as positive and negative controls. Results In the clinical isolates, the sensitivity of the tests was 99.5% for Vitek and 95.3% for Phoenix. There were no significant differences between the 2 systems in the control strains. Execution of the expert system raised the sensitivity of Phoenix to 100%. However, the Vitek 2 expert system considered the results obtained in 7 strains with ESBL-positive tests to be incoherent. Conclusion Confirmatory testing for ESBL production with the Vitek 2 system (AST-N058 card) showed higher sensitivity than the Phoenix (UNMIC-ID 62 panel) system. Nevertheless, the performance of the expert systems in the 2 automated tests was similar for ESBL detection in E. coli and K. pneumonia (AU)

[Comparative assessment of the Vitek 2 and Phoenix systems for detection of extended-spectrum beta-lactamases]. / Comparación entre las pruebas para la detección de betalactamasas de espectro extendido de los sistemas Vitek 2 y Phoenix.

INTRODUCTION AND PURPOSE: Detection of beta-lactam resistance in Escherichia coli and Klebsiella pneumoniae strains is clinically relevant. Moreover, it is important to differentiate between extended-spectrum beta-lactamase (ESBL) production and other mechanisms of resistance to avoid inadequate treatment of infection caused by these strains. The aim of this study was to compare the performance of the Vitek 2 and BD Phoenix automated systems for confirmatory testing of ESBL production. MATERIAL AND METHODS: A total of 193 clinical isolates of phenotypically confirmed ESBL producers (174 E. coli and 19 K. pneumoniae) were assayed by the Vitek 2 and BD Phoenix systems using AST-N058 cards and UNMIC/ID-62 panels, respectively. The double-disk synergy test and the Etest were used as phenotype reference methods. Twelve strains characterized by genotyping were used as positive and negative controls. RESULTS: In the clinical isolates, the sensitivity of the tests was 99.5% for Vitek and 95.3% for Phoenix. There were no significant differences between the 2 systems in the control strains. Execution of the expert system raised the sensitivity of Phoenix to 100%. However, the Vitek 2 expert system considered the results obtained in 7 strains with ESBL-positive tests to be incoherent. CONCLUSION: Confirmatory testing for ESBL production with the Vitek 2 system (AST-N058 card) showed higher sensitivity than the Phoenix (UNMIC-ID 62 panel) system. Nevertheless, the performance of the expert systems in the 2 automated tests was similar for ESBL detection in E. coli and K. pneumoniae.

Hepatitis B virus genotyping based on cluster analysis of the region involved in lamivudine resistance.

Hepatitis B virus (HBV) genotyping and treatment resistances analysis provide key information for the study of infected patients. Among the existing HBV genotyping methods, restriction fragment length polymorphism (RFLP) based methods are used widely, but HBV genetic variability may lead to wrong results. A simple method for HBV genotyping is described. This single assay provides information related to both genotyping and lamivudine resistance. measuring genotyping reliability. A short region including the YMDD motif of the polymerase gene was analyzed using cluster analysis of 55 isolates. To discriminate the seven HBV genotypes, a selected fragment was used as representative of each genotype (consensus sequences). Comparison between complete genomes from GenBank and from the YMDD analysis using PHILIP package was used for method testing. Sequencing of 102 different serum samples was carried out, and the results were compared with representative sequences. Consensus sequences were chosen corresponding to the different HBV genotypes. Statistical comparison between our method and others gives more than 90% of coincidences with a critical level of 0.056. Comparison between RFLP and the method described gives 3% of discordance results and 3% of untypables samples by RFLP. All the discordant results observed had a change in the pre-S sequence which introduced a new restriction site.

Uso combinado de amplificación aleatoria de polimorfis model ADN (RAPD) y reacción en cadena de la polimerasa (touchdown PCR) en el estudio epidemiológico de Aspergillus fumigatus / Combined used of RAPD and touchdown PCR for epidemiological studies of Aspergillus fumigatus

INTRODUCCIÓN. Aspergillus fumigatus es un hongo filamentoso que se comporta como patógeno oportunista y constituye una de las complicaciones infecciosas más importantes en los pacientes inmunocomprometidos. Los brotes nosocomiales de aspergilosis son cada vez más frecuentes, pero su identificación y caracterización epidemiológica es lenta y laboriosa. OBJETIVO. Describir un método rápido, sensible y específico para la identificación de A. fumigatus y su caracterización genotípica dentro de las posibilidades diagnósticas habituales en un laboratorio clínico de microbiología. MÉTODOS. Se utilizaron cepas de A. fumigatus procedentes de pacientes con aspergilosis invasivas (n = 4), medio ambiente hospitalario (n = 5) y colecciones de referencia (n = 1), así como otras especies fúngicas filogenéticamente próximas aisladas de pacientes (n = 1), del medio hospitalario (n = 6) o de colecciones de referencia (n = 1). La identificación de A. fumigatus se realizó tanto por métodos fenotípicos clásicos como mediante touchdown PCR (reacción en cadena de la polimerasa). La caracterización genotípica se llevó a cabo por RAPD (polimorfismo derivado de la amplificación aleatoria de ADN), comparando distintos protocolos de amplificación y tipos de primer (OPZ-19 y R-108) en relación con su poder resolutivo y reproducibilidad. RESULTADOS. Los resultados de la identificación fenotípica y molecular coincidieron plenamente. La caracterización molecular por RAPD presentó los mejores resultados, en cuanto a reproducibilidad y resolución se refiere, con el primer R-108 y tiempo prolongado de transición entre hibridación y elongación. CONCLUSIÓN. El análisis por RAPD es un método seguro y rápido para la caracterización genotípica de A. fumigatus cuyos patrones de bandas son fáciles de interpretar y reproducir cuando se prolonga drásticamente el tiempo de transición entre la hibridación y la extensión. El uso combinado de touchdown PCR y análisis por RAPD constituye un método sensible y exacto para la resolución de brotes nosocomiales por A. fumigatus (AU)

Combined used of RAPD and touchdown PCR for epidemiological studies of Aspergillus fumigatus.

INTRODUCTION: Aspergillus fumigatus is a filamentous fungus that acts as an opportunistic pathogen and has emerged as a major problem in immunosuppressed patients. Nosocomial outbreaks of aspergillosis are becoming more frequent, but their identification and epidemiological characterization is slow and difficult. OBJECTIVE: Description of a fast, sensitive, specific method to identify and fingerprint A. fumigatus using methodology available in clinical laboratories. METHODS: We studied several strains of A. fumigatus isolated from patients with invasive aspergillosis (n = 4), the hospital environment (n = 5) and reference cultures (n = 1), as well as other close phylogenetic fungal species from patients (n = 1), hospital environment (n = 6) and reference cultures (n = 1). A. fumigatus was identified by both touchdown PCR and conventional phenotyping methods. Genotyping was performed with random amplification of polymorphic DNA (RAPD) analysis, comparing the results from two primers (OPZ-19 and R-108) and different amplification protocols with regard to band resolution and reproducibility. RESULTS: Touchdown PCR and phenotype results were identical. Best RAPD results were obtained with the R-108 primer and considerably longer ramp times between annealing and extension. CONCLUSION: RAPD analysis is a fast, reliable tool for DNA fingerprinting. Patterns may be easier to repeat and interpret when longer ramp times are used. Touchdown PCR combined with RAPD analysis is a sensitive, accurate method for managing clinical outbreaks of Aspergillus fumigatus.

Bacteriemia en una niña con rabdomiosarcoma / Bacteriemia in a girl with rhabdomyosarcoma

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Diarrea por adenovirus y astrovirus en pacientes inmunodeficientes hospitalizados / Adenovirus and astrovirus diarrhea in immunocompromissed hospitalized patients

Fundamento. La diarrea, aguda o crónica, es una complicación común en los pacientes inmunodeprimidos tales como los infectados por el virus de la inmunodeficiencia humana (VIH), sometidos a trasplantes de médula ósea o de órgano sólido y aquéllos con leucemias u otras alteraciones del sistema inmunitario. Dada la importancia de reconocer las posibles etiologías de la diarrea a al ahora de administrar una terapia antimicrobiana específica o evitar un diagnóstico incorrecto de rechazo postrasplante, hemos investigado la presencia de antígeno de astrovirus y adenovirus en las heces de pacientes inmunodeprimidos. Pacientes y métodos. Se analizaron las heces de 258 pacientes inmunodeprimidos hospitalizados en el Complejo Hospitalaria Universitario de Santiago de Compostela y diagnosticados de diarrea durante 1997-99. La detección de los antígenos víricos se realizó mediante enzimoinmunoanálisis (EIA). También se analizaron para otros enteropatógenos comunes. Resultados. El antígeno de adenovirus fue positivo en 5 casos (2 por ciento) y el astrovirus en 12 (5 por ciento). Los pacientes más frecuentemente afectados fueron los prematuros y los hematológicos. Se detectó antígeno de astrovirus en tres pacientes infectados por VIH. La mayoría de los casos positivos presentaban una alteración de la flora intestinal o presencia de toxina de Clostridium difficile, ambas situaciones relacionadas con tratamiento antibiótico prolongado. Conclusiones. Los astrovirus y los adenovirus son enteropatógenos a considerar en individuos inmunocomprometidos hospitalizados. Es, pues, conveniente realizar un diagnóstico certero de la etiología de la diarrea de cara a la administración de un tratamiento antimicrobiano, en los casos en que éste sea necesario, o evitar un diagnóstico incorrecto de rechazo postrasplanteadenovirus and astrovirus antigen in faeces from different immunosupressed (AU)