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OBJECTIVES: Becton-Dickinson recently developed the Phoenix™ CPO (carbapenemase-producing organism) Detect Test, a growth-based test embedded in Gram-negative (GN) panels for the detection and confirmation of bacteria producing class A, B and D carbapenemases. This study aimed to (a) determine the performance of the CPO test, and (b) assess its added value in routine diagnostic workflows. METHODS: The performance of the BD Phoenix CPO test was analysed retrospectively on a collection of 185 molecularly characterized strains, including 92 CPOs, and prospectively on 135 and 160 routine isolates with and without CPO suspicion, respectively. RESULTS: In the retrospective study the CPO test exhibited 92.4% accuracy (95%CI 87.6-95.8), 97.8% sensitivity (95%CI 92.4-99.7) and 87.1% specificity (95%CI 78.6-93.2) for carbapenemase detection. The CPO test provided a classification to class A, B, and D for 81.3% of detected carbapenemases with 94.6% accuracy (95%CI 86.7-98.5). In the prospective study the CPO test detection performance showed 77.8% accuracy (95%CI 68.8-84.5), 100% sensitivity (95%CI 91.2-100) and 67.8% specificity (95%CI 57.3-77.1) with 135 CPO-suspicious isolates and 98.8% accuracy and specificity (95%CI 95.6-99.9) with 160 non-CPO-suspicious isolates. Compared to routine testing, the implementation of the CPO test allowed a mean reduction of 21.3 h (95%CI 17.6-25) in turnaround time, 16.8 min (95%CI 13.4-20.2) in hands-on time, and 20.6 CHF (95%CI 16.5-24.8) in costs. CONCLUSIONS: The CPO test is reliable for the detection of CPO with a high sensitivity. However, the relatively low detection specificity required the use of additional confirmatory methods. The carbapenemase classification accuracy is robust in providing preliminary results before molecular characterization. Finally, the implementation of the test in routine workflows allowed a significant reduction in turnaround time, hands-on time and cost compared to the conventional approach.
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Proteínas Bacterianas/metabolismo , Técnicas Bacteriológicas/métodos , Bacterias Gramnegativas/enzimología , Pruebas de Sensibilidad Microbiana/métodos , beta-Lactamasas/metabolismo , Proteínas Bacterianas/clasificación , Pruebas Diagnósticas de Rutina , Bacterias Gramnegativas/aislamiento & purificación , Humanos , Estudios Prospectivos , Estudios Retrospectivos , Sensibilidad y Especificidad , Factores de Tiempo , beta-Lactamasas/clasificaciónRESUMEN
Outbreaks of Streptococcus pyogenes hypervirulent clones are constant public health threats. In western Switzerland, an increase of severe cases of S. pyogenes invasive infections was observed between December 2015 and March 2016. Our aim was (i) to investigate these cases by the use of Whole Genome Sequencing (WGS) and (ii) to determine the specific virulome and resistome of each isolate in order to undertake adequate public health measures. Eleven Streptococcus pyogenes strains isolated from 11 patients with severe invasive infections between December 13, 2015 and March 12, 2016 were included in our study. Practically, emm-typing, MLST and WGS were used to investigate the relatedness between the isolates. The presence of virulence and antibiotic resistance genes as well as mutations in transcriptional regulators of virulence and in genes encoding for antibiotic targets were assessed. Three and two groups of isolates shared the same emm-type and ST type, respectively. Single Nucleotide Polymorphism (SNP) analysis revealed 14 to 32 SNPs between the strains of the same emm-type group, ruling out the possibility of a clonal outbreak. Mutations found in covS and rocA could partially explain an increased virulence. As these reassuring results were obtained in less than 10 days, no specific hospital hygiene and no dedicated public health measures had to be undertaken. WGS is a powerful technique to discriminate between closely related strains, excluding an outbreak in less than 10 days. Moreover, WGS provided extensive data on the virulome and resistome of all these strains.
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Técnicas Bacteriológicas/métodos , Brotes de Enfermedades , Técnicas de Diagnóstico Molecular/métodos , Infecciones Estreptocócicas/diagnóstico , Infecciones Estreptocócicas/epidemiología , Streptococcus pyogenes/aislamiento & purificación , Secuenciación Completa del Genoma/métodos , Adolescente , Anciano , Niño , Preescolar , Farmacorresistencia Bacteriana , Femenino , Genotipo , Humanos , Lactante , Masculino , Persona de Mediana Edad , Tipificación Molecular/métodos , Suiza/epidemiología , Factores de Virulencia/genéticaRESUMEN
Bacillus cereus bacteraemia can be severe, especially among patients with haematologic malignancy. We retrospectively reviewed first episodes of true B. cereus bacteraemia (more than one positive bottle plus signs of infection) at our institution between 1997 and 2013 with the aim to compare haematologic versus nonhaematologic patients and analyse episodes with complicated outcome. Among 56 episodes of positive-blood cultures for B. cereus, 21 were considered significant. Median age was 54 years (range 23-82 years). Ten patients (48%) had a haematologic malignancy; all were neutropenic at the time of B. cereus bacteraemia. Nonhaematologic patients were either intravenous drug users (n = 3, 14%), polytraumatized (n = 3, 14%) or had multiple chronic comorbidities (n = 5, 24%). Most episodes were hospital acquired (15, 71%). Sources of bacteraemia were intravascular catheter (n = 11, 52%), digestive tract (n = 6, 29%), drug injection (n = 3, 14%) and wound (n = 1, 5%). Adequate antibiotic therapy was provided to 18 patients (86%) during a median of 17 days (range 2-253 days). The intravascular catheter was removed in eight cases (42%). Three haematologic patients had a complicated course with neurologic complications (meningoencephalitis and cerebral abscesses). Complications appeared to be associated with catheter infection (100% of complicated cases vs. 29% of noncomplicated cases). In conclusion, B. cereus bacteraemia can have a complicated course in a subset of patients, mainly those with haematologic malignancy. Catheter infection may be associated with a worse outcome with frequent neurologic complications.
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OBJECTIVES: The management of bloodstream infection, a life-threatening disease, largely relies on early detection of infecting microorganisms and accurate determination of their antibiotic susceptibility to reduce both mortality and morbidity. Recently we developed a new technique based on atomic force microscopy capable of detecting movements of biologic samples at the nanoscale. Such sensor is able to monitor the response of bacteria to antibiotic's pressure, allowing a fast and versatile susceptibility test. Furthermore, rapid preparation of a bacterial pellet from a positive blood culture can improve downstream characterization of the recovered pathogen as a result of the increased bacterial concentration obtained. METHODS: Using artificially inoculated blood cultures, we combined these two innovative procedures and validated them in double-blind experiments to determine the susceptibility and resistance of Escherichia coli strains (ATCC 25933 as susceptible and a characterized clinical isolate as resistant strain) towards a selection of antibiotics commonly used in clinical settings. RESULTS: On the basis of the variance of the sensor movements, we were able to positively discriminate the resistant from the susceptible E. coli strains in 16 of 17 blindly investigated cases. Furthermore, we defined a variance change threshold of 60% that discriminates susceptible from resistant strains. CONCLUSIONS: By combining the nanomotion sensor with the rapid preparation method of blood culture pellets, we obtained an innovative, rapid and relatively accurate method for antibiotic susceptibility test directly from positive blood culture bottles, without the need for bacterial subculture.
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Antibacterianos/farmacología , Bacteriemia/microbiología , Infecciones por Escherichia coli/microbiología , Escherichia coli/efectos de los fármacos , Ampicilina/farmacología , Ampicilina/uso terapéutico , Antibacterianos/uso terapéutico , Bacteriemia/tratamiento farmacológico , Cultivo de Sangre , Ceftriaxona/farmacología , Ceftriaxona/uso terapéutico , Ciprofloxacina/farmacología , Ciprofloxacina/uso terapéutico , Método Doble Ciego , Farmacorresistencia Bacteriana , Escherichia coli/clasificación , Infecciones por Escherichia coli/tratamiento farmacológico , Humanos , Pruebas de Sensibilidad Microbiana , Microscopía de Fuerza Atómica , NanotecnologíaRESUMEN
We report the case of a lung transplant recipient in whom the diagnosis of visceral leishmaniasis (VL) was made by detection of parasites in a peripheral blood smear when the parasite load already reached 8.9 × 103 parasites/mL. We demonstrated that the VL diagnosis could have been done months before the development of symptoms by the use of Leishmania-specific real-time polymerase chain reaction (PCR), suggesting the role of preemptive PCR-based diagnosis in transplant recipients at risk for VL.
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Anfotericina B/uso terapéutico , Antiprotozoarios/uso terapéutico , ADN Protozoario/aislamiento & purificación , Fibrosis Pulmonar Idiopática/cirugía , Leishmania/aislamiento & purificación , Leishmaniasis Visceral/diagnóstico , Trasplante de Pulmón/efectos adversos , Anfotericina B/administración & dosificación , Antiprotozoarios/administración & dosificación , Diagnóstico Precoz , Humanos , Leishmaniasis Visceral/sangre , Leishmaniasis Visceral/tratamiento farmacológico , Leishmaniasis Visceral/parasitología , Masculino , Persona de Mediana Edad , Carga de Parásitos , Reacción en Cadena en Tiempo Real de la Polimerasa , Sensibilidad y Especificidad , Receptores de TrasplantesAsunto(s)
Antibacterianos/farmacología , Bacteriemia/microbiología , Técnicas Bacteriológicas/métodos , Colistina/farmacología , Farmacorresistencia Bacteriana , Infecciones por Enterobacteriaceae/microbiología , Enterobacteriaceae/efectos de los fármacos , Enterobacteriaceae/genética , Enterobacteriaceae/aislamiento & purificación , Humanos , Tamizaje Masivo/métodos , Plásmidos/análisisRESUMEN
Since late 2014, multiple cases of abscesses and boils due to methicillin-susceptible Staphylococcus aureus (MSSA) expressing the Panton-Valentine leucocidin (PVL) were observed in Eritrean asylum seekers in Lausanne, Switzerland. Strains isolated from infected Eritrean and non-Eritrean patients were compared by whole genome sequencing to determine whether these numerous cases result from an outbreak. The genome of S. aureus PVL-producing strains were sequenced and compared. Clinical and epidemiological characteristics of patients infected by PVL-producing strains were investigated. This work reports 15 cases of infections due to PVL-producing strains affecting mostly asylum seekers (n = 10), people working with refugees and/or exposed to Africans (n = 3). Most infections were due to closely related strains of CC152 (n = 8) and CC15 (n = 3), two distantly related (>34 000 core single nucleotide polymorphisms) clonal complexes. An epidemiological link between the 15 cases could be ruled out by whole genome sequencing (33 to 172 core single nucleotide polymorphisms between the different strains of a given complex). Altogether, these results reflect the probable high incidence of CC15 and CC152 PVL-producing strains in eastern Africa. Clinicians facing unusual skin infections in African refugees (or in any person returning from this region of high endemicity) should consider S. aureus PVL-producer before suspecting rare infections such as leishmaniasis or rickettsiosis. Clinicians should also remember that PVL are frequently expressed by MSSA in some regions of the world and that antibiotics that are efficient on toxin expression, such as clindamycin, represent the best therapeutic option.
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Toxinas Bacterianas/genética , Exotoxinas/genética , Leucocidinas/genética , Refugiados , Infecciones Cutáneas Estafilocócicas/microbiología , Staphylococcus aureus/genética , Adolescente , Adulto , Toxinas Bacterianas/biosíntesis , Niño , Preescolar , Brotes de Enfermedades , Eritrea/epidemiología , Exotoxinas/biosíntesis , Femenino , Genoma Bacteriano , Genómica , Humanos , Leucocidinas/biosíntesis , Masculino , Persona de Mediana Edad , Filogenia , Polimorfismo de Nucleótido Simple , Infecciones Cutáneas Estafilocócicas/epidemiología , Staphylococcus aureus/clasificación , Adulto JovenRESUMEN
Airborne precautions are required at hospital admission for patients with suspected pulmonary tuberculosis. The isolation is maintained until 3 serially collected sputum smears are acid-fast bacilli negative, a time- and labor-intensive method with limited sensitivity and specificity, which has a great impact on patient flow management. We evaluated the possibility of replacing the result of microscopy by the semiquantitative result of the molecular point-of-care test Xpert MTB/RIF to assess patients' transmission risk to quickly guide airborne isolation decisions in low-endemic countries. The performance of the Xpert MTB/RIF, used as a first-line test, was compared to the results of microscopy for specimens (n=242) collected from May 2010 to December 2014 in Lausanne, Switzerland. The sensitivity and specificity of Xpert MTB/RIF were 91.5% (65/71) and 99.6% (170/171), respectively, vs. 64.8% (46/71) and 94.2% (161/171) for microscopy. Samples with negative Xpert MTB/RIF were all smear negative for Mycobacterium tuberculosis (negative predictive value, 100%). The semiquantitative results of Xpert MTB/RIF-high, medium, low or very low-were found to correlate with acid-fast bacilli detection: positive predictive value of 100% (6/6), 96.5% (27/28), 52.2% (12/23) and 11.1% (1/9) respectively. Finally, when including clinical criteria, we identified 11 smear-negative but Xpert MTB/RIF-positive patients with a significant transmission potential. In conclusion, our data support the introduction of an Xpert MTB/RIF-based strategy as a replacement of smear microscopy for a faster and more accurate management of tuberculosis patients' transmission risk in a low-prevalence country.
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Microscopía/métodos , Técnicas de Diagnóstico Molecular/métodos , Mycobacterium tuberculosis/aislamiento & purificación , Esputo/microbiología , Tuberculosis Pulmonar/diagnóstico , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Mycobacterium tuberculosis/citología , Mycobacterium tuberculosis/genética , Sistemas de Atención de Punto , Valor Predictivo de las Pruebas , Sensibilidad y Especificidad , Suiza , Adulto JovenRESUMEN
BACKGROUND: During an environmental investigation of Pseudomonas aeruginosa in intensive care units, the liquid hand soap was found to be highly contaminated (up to 8 × 10(5)cfu/g) with this pathogen. It had been used over the previous five months and was probably contaminated during manufacturing. AIM: To evaluate the burden of this contamination on patients by conducting an epidemiological investigation using molecular typing combined with whole genome sequencing (WGS). METHODS: P. aeruginosa isolates from clinical specimens were analysed by double locus sequence typing (DLST) and compared with isolates recovered from the soap. Medical charts of patients infected with a genotype identical to those found in the soap were reviewed. WGS was performed on soap and patient isolates sharing the same genotype. FINDINGS: P. aeruginosa isolates (N = 776) were available in 358/382 patients (93.7%). Only three patients (0.8%) were infected with a genotype found in the soap. Epidemiological investigations showed that the first patient was not exposed to the soap, the second could have been exposed, and the third was indeed exposed. WGS showed a high number of core single nucleotide polymorphism differences between patients and soap isolates. No close genetic association was observed between soap and patient isolates, ruling out the hypothesis of transmission. CONCLUSION: Despite a highly contaminated soap, the combined investigation with DLST and WGS ruled out any impact on patients. Hand hygiene performed with alcohol-based solution for >15 years was probably the main reason. However, such contamination represents a putative reservoir of pathogens that should be avoided in the hospital setting.
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Microbiología Ambiental , Infecciones por Pseudomonas/epidemiología , Pseudomonas aeruginosa/aislamiento & purificación , Jabones , Genoma Bacteriano , Genotipo , Humanos , Tipificación Molecular , Infecciones por Pseudomonas/microbiología , Pseudomonas aeruginosa/clasificación , Pseudomonas aeruginosa/genética , Análisis de Secuencia de ADN , Centros de Atención TerciariaRESUMEN
Automation was introduced many years ago in several diagnostic disciplines such as chemistry, haematology and molecular biology. The first laboratory automation system for clinical bacteriology was released in 2006, and it rapidly proved its value by increasing productivity, allowing a continuous increase in sample volumes despite limited budgets and personnel shortages. Today, two major manufacturers, BD Kiestra and Copan, are commercializing partial or complete laboratory automation systems for bacteriology. The laboratory automation systems are rapidly evolving to provide improved hardware and software solutions to optimize laboratory efficiency. However, the complex parameters of the laboratory and automation systems must be considered to determine the best system for each given laboratory. We address several topics on laboratory automation that may help clinical bacteriologists to understand the particularities and operative modalities of the different systems. We present (a) a comparison of the engineering and technical features of the various elements composing the two different automated systems currently available, (b) the system workflows of partial and complete laboratory automation, which define the basis for laboratory reorganization required to optimize system efficiency, (c) the concept of digital imaging and telebacteriology, (d) the connectivity of laboratory automation to the laboratory information system, (e) the general advantages and disadvantages as well as the expected impacts provided by laboratory automation and (f) the laboratory data required to conduct a workflow assessment to determine the best configuration of an automated system for the laboratory activities and specificities.
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Automatización de Laboratorios , Técnicas Bacteriológicas , Bacteriología , Laboratorios , Automatización de Laboratorios/instrumentación , Automatización de Laboratorios/métodos , Automatización de Laboratorios/normas , Técnicas Bacteriológicas/instrumentación , Técnicas Bacteriológicas/métodos , Técnicas Bacteriológicas/normas , Bacteriología/normas , Humanos , Laboratorios/normasRESUMEN
Despite the development of novel typing methods based on whole genome sequencing, most laboratories still rely on classical molecular methods for outbreak investigation or surveillance. Reference methods for Clostridium difficile include ribotyping and pulsed-field gel electrophoresis, which are band-comparing methods often difficult to establish and which require reference strain collections. Here, we present the double locus sequence typing (DLST) scheme as a tool to analyse C. difficile isolates. Using a collection of clinical C. difficile isolates recovered during a 1-year period, we evaluated the performance of DLST and compared the results to multilocus sequence typing (MLST), a sequence-based method that has been used to study the structure of bacterial populations and highlight major clones. DLST had a higher discriminatory power compared to MLST (Simpson's index of diversity of 0.979 versus 0.965) and successfully identified all isolates of the study (100 % typeability). Previous studies showed that the discriminatory power of ribotyping was comparable to that of MLST; thus, DLST might be more discriminatory than ribotyping. DLST is easy to establish and provides several advantages, including absence of DNA extraction [polymerase chain reaction (PCR) is performed on colonies], no specific instrumentation, low cost and unambiguous definition of types. Moreover, the implementation of a DLST typing scheme on an Internet database, such as that previously done for Staphylococcus aureus and Pseudomonas aeruginosa ( http://www.dlst.org ), will allow users to easily obtain the DLST type by submitting directly sequencing files and will avoid problems associated with multiple databases.
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Clostridioides difficile/clasificación , Clostridioides difficile/aislamiento & purificación , Infecciones por Clostridium/diagnóstico , Tipificación de Secuencias Multilocus/métodos , Secuencia de Bases , Clostridioides difficile/genética , Infecciones por Clostridium/epidemiología , Infecciones por Clostridium/microbiología , Infección Hospitalaria/microbiología , ADN Bacteriano/genética , Humanos , Epidemiología Molecular , Análisis de Secuencia de ADN , Suiza/epidemiologíaAsunto(s)
Aerococcus/aislamiento & purificación , Infecciones por Bacterias Grampositivas/diagnóstico , Infecciones por Bacterias Grampositivas/epidemiología , Técnicas de Diagnóstico Molecular/métodos , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos , Aerococcus/química , Aerococcus/genética , Anciano , Técnicas Bacteriológicas/métodos , ADN Bacteriano/química , ADN Bacteriano/genética , ADN Ribosómico/química , ADN Ribosómico/genética , Femenino , Infecciones por Bacterias Grampositivas/microbiología , Humanos , Masculino , Reacción en Cadena de la Polimerasa , ARN Ribosómico 16S/genéticaRESUMEN
The impact of round-the-clock cerebrospinal fluid (CSF) Gram stain on overnight empirical therapy for suspected central nervous system (CNS) infections was investigated. All consecutive overnight CSF Gram stains between 2006 and 2011 were included. The impact of a positive or a negative test on empirical therapy was evaluated and compared to other clinical and biological indications based on institutional guidelines. Bacterial CNS infection was documented in 51/241 suspected cases. Overnight CSF Gram stain was positive in 24/51. Upon validation, there were two false-positive and one false-negative results. The sensitivity and specificity were 41 and 99 %, respectively. All patients but one had other indications for empirical therapy than Gram stain alone. Upon obtaining the Gram result, empirical therapy was modified in 7/24, including the addition of an appropriate agent (1), addition of unnecessary agents (3) and simplification of unnecessary combination therapy (3/11). Among 74 cases with a negative CSF Gram stain and without formal indication for empirical therapy, antibiotics were withheld in only 29. Round-the-clock CSF Gram stain had a low impact on overnight empirical therapy for suspected CNS infections and was associated with several misinterpretation errors. Clinicians showed little confidence in CSF direct examination for simplifying or withholding therapy before definite microbiological results.
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Líquido Cefalorraquídeo/microbiología , Infecciones Comunitarias Adquiridas/diagnóstico , Infección Hospitalaria/diagnóstico , Violeta de Genciana , Meningitis Bacterianas/diagnóstico , Fenazinas , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Antibacterianos/uso terapéutico , Niño , Preescolar , Infecciones Comunitarias Adquiridas/microbiología , Infección Hospitalaria/microbiología , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Meningitis Bacterianas/tratamiento farmacológico , Meningitis Bacterianas/microbiología , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa , Estudios Retrospectivos , Sensibilidad y Especificidad , Coloración y Etiquetado/métodos , Centros de Atención Terciaria , Adulto JovenRESUMEN
Blood culture remains the best approach to identify the incriminating microorganisms when a bloodstream infection is suspected, and to guarantee that the antimicrobial treatment is adequate. Major improvements have been made in the last years to increase the sensitivity and specificity and to reduce the time to identification of microorganisms recovered from blood cultures. Among other factors, the introduction in clinical microbiology laboratories of the matrix-assisted laser desorption ionization time-of-flight mass spectrometry technology revolutionized the identification of microorganisms whereas the introduction of nucleic-acid-based methods, such as DNA hybridization or rapid PCR-based test, significantly reduce the time to results. Together with traditional antimicrobial susceptibility testing, new rapid methods for the detection of resistance mechanisms respond to major epidemiological concerns such as methicillin-resistant Staphylococcus aureus, extended-spectrum ß-lactamase or carbapenemases. This review presents and discusses the recent developments in microbial diagnosis of bloodstream infections based on blood cultures.
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Bacteriemia/diagnóstico , Bacterias/aislamiento & purificación , Técnicas Bacteriológicas/métodos , Sangre/microbiología , Bacterias/crecimiento & desarrollo , Humanos , Técnicas de Diagnóstico Molecular/métodos , Sensibilidad y Especificidad , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos , Factores de TiempoRESUMEN
Detection of cryptococcal antigen in serum or cerebrospinal fluid allows cryptococcal meningitis diagnosis within few hours with >90% sensitivity. In an HIV-positive patient with Cryptococcus neoformans meningitis, initial antigen detection by immunoagglutination was negative. We thus evaluated a new immunochromatographic detection assay that exhibited a higher sensitivity.
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Carbapenemases should be accurately and rapidly detected, given their possible epidemiological spread and their impact on treatment options. Here, we developed a simple, easy and rapid matrix-assisted laser desorption ionization-time of flight (MALDI-TOF)-based assay to detect carbapenemases and compared this innovative test with four other diagnostic approaches on 47 clinical isolates. Tandem mass spectrometry (MS-MS) was also used to determine accurately the amount of antibiotic present in the supernatant after 1 h of incubation and both MALDI-TOF and MS-MS approaches exhibited a 100% sensitivity and a 100% specificity. By comparison, molecular genetic techniques (Check-MDR Carba PCR and Check-MDR CT103 microarray) showed a 90.5% sensitivity and a 100% specificity, as two strains of Aeromonas were not detected because their chromosomal carbapenemase is not targeted by probes used in both kits. Altogether, this innovative MALDI-TOF-based approach that uses a stable 10-µg disk of ertapenem was highly efficient in detecting carbapenemase, with a sensitivity higher than that of PCR and microarray.
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Proteínas Bacterianas/análisis , Técnicas Bacteriológicas/métodos , Bacterias Gramnegativas/enzimología , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos , beta-Lactamasas/análisis , Análisis por Micromatrices/métodos , Reacción en Cadena de la Polimerasa/métodos , Sensibilidad y Especificidad , Espectrometría de Masas en Tándem/métodosRESUMEN
OBJECTIVES: Although infectious disease (ID) consultation has been associated with lower mortality in Staphylococcus aureus bloodstream infections, it is still not mandatory in many centers. This study aimed at assessing the impact of ID consultation on diagnostic and therapeutic management of methicillin-resistant S. aureus (MRSA) bacteremia. METHODS: Retrospective cohort study of all patients with MRSA bacteremia from 2001 to 2010. ID consultations were obtained on request between 2001 and 2006 and became mandatory since 2007. RESULTS: 156 episodes of MRSA bacteremia were included, mostly from central venous catheter (32%) and skin and soft tissue (19%) infections. ID consultation coverage was 58% between 2001 and 2006 and 91% between 2007 and 2010. ID consultation was associated with more echocardiography (59% vs. 26%, p < 0.01), vancomycin trough level measurements (99% vs. 77%, p < 0.01), follow-up blood cultures (71% vs. 50%, p = 0.05), deep-seated infections (43% vs. 16%, p < 0.01), more frequent infection source control (83% vs. 57%, p = 0.03), a longer duration of MRSA-active therapy (median and IQR: 17 days, 13-30, vs. 12, 3-14, p < 0.01) and a 20% reduction in 7-day, 30-day and in-hospital mortality. CONCLUSIONS: ID consultation was associated with a better management of patients with MRSA bacteremia and a reduced mortality.
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Bacteriemia/tratamiento farmacológico , Bacteriemia/microbiología , Staphylococcus aureus Resistente a Meticilina , Derivación y Consulta , Infecciones de los Tejidos Blandos/tratamiento farmacológico , Infecciones Cutáneas Estafilocócicas/tratamiento farmacológico , Anciano , Anciano de 80 o más Años , Antibacterianos/administración & dosificación , Antibacterianos/sangre , Bacteriemia/diagnóstico , Bacteriemia/mortalidad , Sangre/microbiología , Infección Hospitalaria/diagnóstico , Infección Hospitalaria/tratamiento farmacológico , Infección Hospitalaria/microbiología , Infección Hospitalaria/mortalidad , Ecocardiografía , Femenino , Mortalidad Hospitalaria/tendencias , Humanos , Infectología , Masculino , Persona de Mediana Edad , Política Organizacional , Guías de Práctica Clínica como Asunto , Derivación y Consulta/tendencias , Estudios Retrospectivos , Infecciones de los Tejidos Blandos/diagnóstico , Infecciones de los Tejidos Blandos/microbiología , Infecciones de los Tejidos Blandos/mortalidad , Infecciones Cutáneas Estafilocócicas/diagnóstico , Infecciones Cutáneas Estafilocócicas/microbiología , Infecciones Cutáneas Estafilocócicas/mortalidad , Vancomicina/administración & dosificación , Vancomicina/sangreRESUMEN
Mycoplasma hominis and Ureaplasma spp. may colonize the human genital tract and have been associated with adverse pregnancy outcomes such as preterm labour and preterm premature rupture of membranes. However, as these bacteria can reside in the normal vaginal flora, there are controversies regarding their true role during pregnancy and so the need to treat these organisms. We therefore conducted a retrospective analysis to evaluate the treatment of genital mycoplasma in 5377 pregnant patients showing symptoms of potential obstetric complications at 25-37 weeks of gestation. Women presenting with symptoms were routinely screened by culture for the presence of these bacteria and treated with clindamycin when positive. Compared with uninfected untreated patients, women treated for genital mycoplasma demonstrated lower rates of premature labour. Indeed preterm birth rates were, respectively, 40.9% and 37.7% in women colonized with Ureaplasma spp. and M. hominis, compared with 44.1% in uncolonized women (Ureaplasma spp., p 0.024; M. hominis, p 0.001). Moreover, a reduction of neonatal complications rates was observed, with 10.9% of newborns developing respiratory diseases in case of Ureaplasma spp. colonization and 5.9% in the presence of M. hominis, compared with 12.8% in the absence of those bacteria (Ureaplasma spp., p 0.050; M. hominis, p <0.001). Microbiological screening of Ureaplasma spp. and/or M. hominis and pre-emptive antibiotic therapy of symptomatic pregnant women in late pregnancy might represent a beneficial strategy to reduce premature labour and neonatal complications.
Asunto(s)
Antibacterianos/uso terapéutico , Clindamicina/uso terapéutico , Infecciones por Mycoplasmatales/tratamiento farmacológico , Complicaciones Infecciosas del Embarazo/tratamiento farmacológico , Nacimiento Prematuro/prevención & control , Infecciones del Sistema Genital/tratamiento farmacológico , Síndrome de Dificultad Respiratoria del Recién Nacido/prevención & control , Adulto , Femenino , Humanos , Recién Nacido , Persona de Mediana Edad , Mycoplasma/crecimiento & desarrollo , Infecciones por Mycoplasmatales/microbiología , Embarazo , Complicaciones Infecciosas del Embarazo/microbiología , Resultado del Embarazo , Nacimiento Prematuro/epidemiología , Nacimiento Prematuro/etiología , Infecciones del Sistema Genital/microbiología , Síndrome de Dificultad Respiratoria del Recién Nacido/complicaciones , Síndrome de Dificultad Respiratoria del Recién Nacido/epidemiología , Síndrome de Dificultad Respiratoria del Recién Nacido/etiología , Estudios Retrospectivos , Ureaplasma/crecimiento & desarrollo , Adulto JovenRESUMEN
Effective empirical treatment is of paramount importance to improve the outcome of patients with Staphylococcus aureus bacteraemia. We aimed to evaluate a PCR-based rapid diagnosis of methicillin resistance (GeneXpert MRSA) after early detection of S. aureus bacteraemia using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). Patients with a first episode of S. aureus bacteraemia identified using MALDI-TOF MS were randomized in a prospective interventional open study between October 2010 and August 2012. In the control group, antibiotic susceptibility testing was performed after MALDI-TOF MS identification on blood culture pellets. In the intervention group, a GeneXpert MRSA was performed after S. aureus identification. The primary outcome was the performance of GeneXpert MRSA directly on blood cultures. We then assessed the impact of early diagnosis of methicillin resistance on the empirical treatment. In all, 197 episodes of S. aureus bacteraemia were included in the study, of which 106 were included in the intervention group. Median time from MALDI-TOF MS identification to GeneXpert MRSA result was 97 min (range 25-250). Detection of methicillin resistance using GeneXpert MRSA had a sensitivity of 99% and a specificity of 100%. There was less unnecessary coverage of MRSA in the intervention group (17.1% versus 29.2%, p 0.09). GeneXpert MRSA was highly reliable in diagnosing methicillin resistance when performed directly on positive blood cultures. This could help to avoid unnecessary prescriptions of anti-MRSA agents and promote the introduction of earlier adequate coverage in unsuspected cases.
Asunto(s)
Bacteriemia/diagnóstico , Técnicas Bacteriológicas/métodos , Staphylococcus aureus Resistente a Meticilina/aislamiento & purificación , Reacción en Cadena de la Polimerasa/métodos , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos , Infecciones Estafilocócicas/diagnóstico , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Bacteriemia/microbiología , Niño , Preescolar , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Staphylococcus aureus Resistente a Meticilina/química , Staphylococcus aureus Resistente a Meticilina/genética , Persona de Mediana Edad , Estudios Prospectivos , Sensibilidad y Especificidad , Infecciones Estafilocócicas/microbiología , Factores de Tiempo , Adulto JovenRESUMEN
We conducted a molecular study of MRSA isolated in Swiss hospitals, including the first five consecutive isolates recovered from blood cultures and the first ten isolates recovered from other sites in newly identified carriers. Among 73 MRSA isolates, 44 different double locus sequence typing (DLST) types and 32 spa types were observed. Most isolates belonged to the NewYork/Japan, the UK-EMRSA-15, the South German and the Berlin clones. In a country with a low to moderate MRSA incidence, inclusion of non-invasive isolates allowed a more accurate description of the diversity.