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1.
Artigo em Inglês | MEDLINE | ID: mdl-31613964

RESUMO

OBJECTIVES: Escherichia coli is characterized by three resistance patterns to ß-lactams/ß-lactamase inhibitors (BLs/BLIs): (i) resistance to ampicillin/sulbactam and susceptibility to amoxicillin/clavulanic acid and piperacillin/tazobactam (RSS); (ii) resistance to ampicillin/sulbactam and amoxicillin/clavulanic acid, and susceptibility to piperacillin/tazobactam (RRS); and (iii) resistance to ampicillin/sulbactam, amoxicillin/clavulanic acid and piperacillin/tazobactam (RRR). These resistance patterns are acquired consecutively, indicating a potential risk of developing resistance to piperacillin/tazobactam, but the precise mechanism of this process is not completely understood. METHODS: Clinical isolates incrementally pressured by piperacillin/tazobactam selection in vitro and in vivo were used. We determined the MIC of piperacillin/tazobactam in the presence and absence of piperacillin/tazobactam pressure. We deciphered the role of the blaTEM genes in the new concept of extended-spectrum resistance to BLs/BLIs (ESRI) using genomic analysis. The activity of ß-lactamase was quantified in these isolates. RESULTS: We show that piperacillin/tazobactam resistance is induced in E. coli carrying blaTEM genes. This resistance is due to the increase in copy numbers and transcription levels of the blaTEM gene, thus increasing ß-lactamase activity and consequently increasing piperacillin/tazobactam MICs. Genome sequencing of two blaTEM-carrying representative isolates showed that piperacillin/tazobactam treatment produced two types of duplications of blaTEM (8 and 60 copies, respectively). In the clinical setting, piperacillin/tazobactam treatment of patients infected by E. coli carrying blaTEM is associated with a risk of therapeutic failure. CONCLUSIONS: This study describes for the first time the ESRI in E. coli. This new concept is very important in the understanding of the mechanism involved in the acquisition of resistance to BLs/BLIs.

2.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-31027868

RESUMO

Listeria monocytogenes is an important cause of meningoencephalitis associated with high mortality. The treatment of choice for listeriosis is ampicillin alone or in combination with gentamicin or penicillin G. However, only low ampicillin concentrations are recorded in the central nervous system (CNS). In this study, we analysed the effect of subinhibitory concentrations of ampicillin on the morphology, growth and survival of L. monocytogenes. The non-inhibitory concentration (NIC), the minimum inhibitory concentration (MIC) and the MIC/NIC ratio were determined. Gram and Live/Dead staining showed aggregates of L. monocytogenes cells when grown at subinhibitory concentrations of ampicillin, with >90% of viable cells. The L. monocytogenes strains tested showed an intermediate heteroresistance to ampicillin, characterised by a MIC/NIC ratio of 4. Our results seem to indicate that both intermediate heteroresistance and the formation of aggregates could play a role in the clinical failure of ampicillin in the treatment of CNS infections caused by L. monocytogenes. However, more studies are necessary to elucidate this question.

3.
Rev. esp. quimioter ; 32(2): 145-155, abr. 2019. tab, graf
Artigo em Inglês | IBECS | ID: ibc-182816

RESUMO

Introduction: Continuous antimicrobial resistance surveillance is recommended by Public Health authorities. We up-dated data from the SMART (Study for Monitoring Antimicrobial Resistance Trends) surveillance study in Spain. Material and methods: The antimicrobial susceptibility data and extended-spectrum beta-lactamase (ESBL) production in isolates recovered from intra-abdominal (IAI) (n=1,429) and urinary tract (UTI) (n=937) infections during the 2016- 2017 SMART study in 10 Spanish hospitals were analysed. Results: Escherichia coli was the most frequently microorganism isolated (48.3% and 53.7%) followed by Klebsiella spp. (11.5% and 21.9%) in IAIs and UTIs, respectively. Figures for Pseudomonas aeruginosa were 9.0% and 6.1%, being more frequently recovered from patients with nosocomial infections. Overall, 9.9% (IAI) and 14.0% (UTI) of E. coli, Klebsiella spp. and Proteus mirabilis isolates were ESBL-producers, being Klebsiella pneumoniae (34.5%) from UTI of nosocomial origin the most frequent. ESBL-producers were higher in patients >60 years in both IAIs and UTIs. As in previous years, amikacin (96.3%-100% susceptibility), ertapenem (84.2%-100%) and imipenem (70.3%- 100%) were the most active antimicrobials tested among Enterobacterales species. The activity of amoxicillin-clavulanic, piperacillin-tazobactam, and ciprofloxacin susceptibility was lower, particularly among ESBL-producers. Ertapenem susceptibility (88.9%-100%) was retained in ESBL-E. coli isolates that were resistant to these antimicrobials but decreased (28.6%-100%) in similar isolates of K. pneumoniae. Conclusions: Continuous antimicrobial resistance surveillance from the SMART study reveals overall maintenance of ESBL-producers in Spain, although with higher presence in isolates from UTIs than from IAIs. Moreover, ertapenem activity was high in E. coli irrespective of ESBL production but decreased in K. pneumoniae, particularly among ESBL-producers


Introducción: Las autoridades de Salud Pública recomiendan la vigilancia continua de la resistencia a los antimicrobianos. Se actualizan los datos del estudio SMART (Study for Monitoring Antimicrobial Resistance Trends) en España. Material y métodos: Se analizaron los datos de sensibilidad antimicrobiana y la producción de betalactamasas de espectro extendido (BLEE) en aislamientos obtenidos en el estudio SMART de infecciones intraabdominales (IIA) (n=1.429) y del tracto urinario (ITU) (n=937) durante 2016-2017 en 10 hospitales españoles. Resultados: Escherichia coli fue el microorganismo más frecuente (54,5% y 57,5%, respectivamente), seguido de Klebsiella spp. (18,4% y 25,4%) en IIA y en ITU. En Pseudomonas aeruginosa estas cifras fueron 9% y 6%, siendo más frecuente en la infección nosocomial. El 9,9% (IIA) y el 14% (ITU) del to-tal de los aislados de E. coli, Klebsiella spp. y Proteus mirabilis producían BLEE, obteniéndose la tasa más alta en Klebsiella pneumoniae (34.5%) en ITU nosocomial. El mayor porcentaje de aislados con BLEE se observó en pacientes >60 años, tanto en IIA como en ITU. Como en años anteriores, amikacina (sensibilidad 96,3%-100%), ertapenem (84,2%-100%) e imipenem (70,3%-100%) fueron los antimicrobianos más activos en Enterobacterales. La sensibilidad a amoxicilina-ácido clavulánico, piperacilina-tazobactam y ciprofloxacino fue menor, en particular en los productores de BLEE. La sensibilidad a ertapenem (88,9%-100%) se mantuvo en E. coli con BLEE resistente a estos antimicrobianos, pero disminuyó (28,6%-100%) en aislados similares de K. pneumoniae. Conclusiones: La vigilancia continua de la resistencia a los antimicrobianos en el estudio SMART revela el mantenimiento de la frecuencia de aislados productores de BLEE en España, pero con mayor presencia en las ITUs que en las IIAs. Además, la sensibilidad a ertapenem fue alta en E. coli con independencia de la producción de BLEE, pero disminuyó en K. pneumoniae, sobre todo en los productores de BLEE


Assuntos
Humanos , Monitoramento de Medicamentos/métodos , Testes de Sensibilidade Microbiana/métodos , Infecções por Bactérias Gram-Negativas/tratamento farmacológico , Bactérias Gram-Negativas/efeitos dos fármacos , Infecções Urinárias/tratamento farmacológico , Infecções Intra-Abdominais/tratamento farmacológico , Resultado do Tratamento , Espanha/epidemiologia
4.
Enferm. infecc. microbiol. clín. (Ed. impr.) ; 37(2): 112-116, feb. 2019. tab
Artigo em Inglês | IBECS | ID: ibc-181151

RESUMO

Introduction: Development of secondary haemophagocytic lymphohistiocytosis (sHLH) in the context of typhoid fever (TF) is a very rare but serious complication. Methods: Description of the first pediatric case of typhoid fever acquired in a non-endemic area complicated by sHLH. A systematic literature review of sHLH in the context of TF was performed with extraction of epidemiological, clinical and laboratory data. Results: The literature search revealed 17 articles (22 patients). Fifteen patients were eligible for data analysis (53.4% children). All patients had fever and pancytopenia. Transaminases and LDH were frequently elevated (46.6%). Salmonella typhi was detected mainly by blood culture (64.3%). All the patients received antibiotics whereas immunomodulation (dexamethasone) was used in two cases. Conclusions: A high suspicion index for this condition is needed even in non-endemic areas. The addition of immunmodulation to standard antimicrobial therapy should be considered in selected cases


Introducción: El síndrome hemofagocítico (HLH) secundario en el contexto de fiebre tifoidea es una complicación rara pero seria. Métodos: Descripción del primer caso pediátrico de fiebre tifoidea adquirida en área no endémica complicada con síndrome hemofagocítico y revisión sistemática de la literatura de casos de HLH secundarios a fiebre tifoidea. Descripción de datos epidemiológicos, clínicos y de laboratorio, diagnóstico y manejo. Resultados: La búsqueda bibliográfica reveló 17 artículos (22 pacientes). Quince pacientes eran elegibles para el análisis (53,4% niños). La fiebre y la pancitopenia estaban siempre presentes, y las transaminasas y la LDH estaban frecuentemente elevados (46,6%). La detección de S. typhi se realizó mediante hemocultivo, principalmente (64,3%). Todos los pacientes reportados recibieron antibióticos; la dexametasona fue usada como tratamiento inmunomodulador en 2 de los casos. Conclusiones: Mantener alto el grado de sospecha de esta condición es necesario, incluso en áreas no endémicas, ya que el uso de tratamiento inmunomodulador junto al tratamiento antimicrobiano puede ser determinante para una evolución clínica favorable


Assuntos
Humanos , Masculino , Criança , Adolescente , Linfo-Histiocitose Hemofagocítica/etiologia , Linfo-Histiocitose Hemofagocítica/epidemiologia , Febre Tifoide/complicações , Febre Tifoide/epidemiologia , Dor Abdominal/etiologia , Distribuição por Idade , Ásia/epidemiologia , Ceftriaxona/uso terapêutico , Países Desenvolvidos , Diagnóstico Diferencial , Doenças Endêmicas , Febre/etiologia , Linfo-Histiocitose Hemofagocítica/tratamento farmacológico , Metilprednisolona/uso terapêutico
5.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-30292326

RESUMO

INTRODUCTION: The genus Aspergillus contains more than 300 species, which are divided into closely related groups called sections. Molecular studies have revealed numerous cryptic species within different sections of this genus, which have different profiles of antifungal susceptibility and lack diagnostic morphological features. However, there are few studies on the prevalence and in vitro antifungal susceptibility of the cryptic species of this genus. The aim of this study was to investigate the distribution of Aspergillus spp. among clinical samples, and to study their in vitro susceptibility to different antifungal drugs. METHOD: Over a period of 2-years (2014-2015), a total of 379 strains of the genus Aspergillus were isolated. Most of the isolates were classified as respiratory colonizations; no cases of invasive aspergillosis were found. The strains were identified by MALDI-TOF mass spectrometry, and susceptibility testing was performed by the EUCAST reference procedure. RESULTS: Twenty species belonging to 8 sections were identified, being A. fumigatus the most prevalent (44.1%). The prevalence of cryptic species was 15.3%, with a clear predominance of A. tubingensis. Among the tested antifungal drugs, amphotericin B was the less active in vitro, followed by triazole drugs and echinocandins. The cryptic species had minimun inhibitory concentrations (MICs) higher than the corresponding type species. CONCLUSIONS: Accurate identification of the genus Aspergillus at the species level and in vitro antifungal susceptibility testing are necessary because, as it has been shown, some species of this genus may show resistance profiles against available antifungal drugs.

6.
J Antimicrob Chemother ; 73(10): 2770-2776, 2018 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-30052973

RESUMO

Background: The appearance and dissemination of MDR among pathogenic bacteria has forced the search for new antimicrobials. Bacteriocins have been proposed as potential alternatives for the treatment of infections due to multiresistant strains. Objectives: To analyse the activity of R-pyocins against clinical isolates of Pseudomonas aeruginosa from patients with cystic fibrosis and other sources and evaluate them as a potential adjuvant or alternative to the current antibiotic treatment. Methods: The activity of R-pyocins against 150 strains of P. aeruginosa isolated from patients with cystic fibrosis or bacteraemia was studied through spot assay. Interactions between R-pyocins and antipseudomonal agents were quantitatively studied by the chequerboard method. Results: The proportion of P. aeruginosa isolates susceptible to R-pyocins was found to be higher in cystic fibrosis isolates compared with bacteraemia isolates (79.41% versus 50%). Moreover, no interactions were found between common antipseudomonal agents and R-pyocin susceptibility, except for the ST175 high-risk clone. Conclusions: Our results highlight the possibility of using R-pyocins as therapeutic agents, alone or as adjuvants, against P. aeruginosa in cystic fibrosis.

7.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-29887216

RESUMO

INTRODUCTION: Development of secondary haemophagocytic lymphohistiocytosis (sHLH) in the context of typhoid fever (TF) is a very rare but serious complication. METHODS: Description of the first pediatric case of typhoid fever acquired in a non-endemic area complicated by sHLH. A systematic literature review of sHLH in the context of TF was performed with extraction of epidemiological, clinical and laboratory data. RESULTS: The literature search revealed 17 articles (22 patients). Fifteen patients were eligible for data analysis (53.4% children). All patients had fever and pancytopenia. Transaminases and LDH were frequently elevated (46.6%). Salmonella typhi was detected mainly by blood culture (64.3%). All the patients received antibiotics whereas immunomodulation (dexamethasone) was used in two cases. CONCLUSIONS: A high suspicion index for this condition is needed even in non-endemic areas. The addition of immunmodulation to standard antimicrobial therapy should be considered in selected cases.

8.
Rev. esp. quimioter ; 31(2): 136-145, abr. 2018. tab, graf
Artigo em Inglês | IBECS | ID: ibc-174509

RESUMO

Introduction. The SMART (Study for Monitoring Antimicrobial Resistance Trends) surveillance study monitors antimicrobial susceptibility and extended spectrum β-lactamases (ESBLs) in Gram-negative bacilli recovered from intra-abdominal infections (IAI). Material and methods. Antimicrobial susceptibility of 5,343 isolates from IAI recovered in 11 centres during the 2011-2015 SMART-Spain program was analysed by standard microdilution (EUCAST criteria) and compared with that from 2002-2010. ESBLs were phenotypically detected. Results. Escherichia coli, the most common isolate, significantly decreased in community acquired IAI (60.9% 2002-2010 vs. 56.1% 2011-2015, P=0.0003). It was followed in prevalence by Klebsiella pneumoniae that increased both in the community (8.9% vs. 10.8%, P=0.016) and nosocomial (9.2% vs. 10.8%, P=0.029) IAI and P. aeruginosa, which significantly increased in community acquired IAI (5.6% vs. 8.0%, P=0.0003). ESBLs were more prevalent in K. pneumoniae (16.3%) than in E. coli(9.5%) of nosocomial origin and were more frequently isolated from elderly patients (>60 years). Considering all Enterobacteriaceae, ertapenem (92.3-100%) and amikacin (95.5%-100%) were the most active antimicrobials. Ertapenem activity, unlike amoxicillin-clavulanate or piperacillin-tazobactam, remained virtually unchanged in ESBL (100%) and non-ESBL (98.8%) E. coli producers. Its activity decreased in ESBL-K. pneumonia (74.7%) but was higher than that of amoxicillin-clavulanate (14.0%) and piperacillin-tazobactam (24.0%). Interestingly, ertapenem susceptibility was maintained in >60% of ESBL isolates that were resistant to amoxicillin-clavulanate, piperacillin-tazobactam or luoroquinolones. Conclusions. SMART-Spain results support current guidelines which include ertapenem as empiric treatment in mild-moderate community-acquired IAI, particularly with ESBL producers. These recommendations will need to be updated with the recently introduction of new antimicrobials


Introducción. El estudio SMART (Study for Monitoring Antimicrobial Resistance Trends) monitoriza la sensibilidad antimicrobiana y las β-lactamasas de espectro extendido (BLEE) en bacilos gramnegativos obtenidos de infecciones intraabdominales (IIA). Material y Métodos. Se ha analizado la sensibilidad antimicrobiana (microdilución estándar, criterios EUCAST) y las BLEE (detección fenotípica) de 5.343 aislados de IIA en 11 centros del programa SMART-España durante 2011-2015 en comparación con 2002-2010. Resultados. Escherichia coli, el microorganismo más prevalente, disminuyó significativamente en las IIA de origen comunitario (60,9% 2002-2010 vs. 56,1% 2011-2015, P=0,0003). Fue seguido en prevalencia por Klebsiella pneumoniae que aumentó tanto en IIA comunitaria (8,9% vs. 10,8%, P=0,016) como nosocomial (9,2% vs. 10,8%, P=0,029) y por P. aeruginosa que aumentó en la IIA comunitaria (5,6% vs. 8,0%, P=0,0003). Las BLEE fueron más prevalentes en la IIA nosocomial por K. pneumoniae(16,3%) que por E. coli(9,5%), siendo más frecuentes en pacientes de mayor edad (>60 años). Considerando todas las Enterobacteriaceae, ertapenem (92,3-100%) y amikacina (95,5%-100%) fueron los antimicrobianos más activos. La sensibilidad a ertapenem, al contrario que a amoxicilina-clavulánico o piperacilina-tazobactam, se mantuvo sin cambios en E. coli con (98,8%) y sin BLEE (100%). Su sensibilidad disminuyó en BLEE-K. pneumoniae (74,7%) pero fue mayor que la de amoxicilina-clavulánico (14,0%) o piperacilina-tazobactam (24,0%). Es de resaltar que esta actividad se mantuvo >60% en los aislados con BLEE resistentes a amoxicilina-clavulánico, piperacilina-tazobactam o fluoroquinolonas.Conclusiones. El estudio SMART-España sustenta las guías actuales que incluyen al ertapenem como tratamiento empírico en la IIA leve-moderada comunitaria, en particular con BLEE. Estas recomendaciones precisaran actualizarse con la reciente introducción de nuevos antimicrobianos


Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Bactérias Gram-Negativas , Infecções por Bactérias Gram-Negativas/microbiologia , Infecções por Bactérias Gram-Negativas/epidemiologia , beta-Lactamases/metabolismo , Infecção Hospitalar/microbiologia , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Combinação de Medicamentos , Escherichia coli , Infecções por Bactérias Gram-Negativas/tratamento farmacológico , Klebsiella pneumoniae , Testes de Sensibilidade Microbiana/métodos , Espanha/epidemiologia , beta-Lactamases/análise , beta-Lactamases/uso terapêutico
10.
PLoS One ; 13(2): e0190389, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29414999

RESUMO

In the present work, we use an exceptional database including 5,359 records of 101 species of Oman's terrestrial reptiles together with spatial tools to infer the spatial patterns of species richness and endemicity, to infer the habitat preference of each species and to better define conservation priorities, with especial focus on the effectiveness of the protected areas in preserving this unique arid fauna. Our results indicate that the sampling effort is not only remarkable from a taxonomic point of view, with multiple observations for most species, but also for the spatial coverage achieved. The observations are distributed almost continuously across the two-dimensional climatic space of Oman defined by the mean annual temperature and the total annual precipitation and across the Principal Component Analysis (PCA) of the multivariate climatic space and are well represented within 17 out of the 20 climatic clusters grouping 10% of the explained climatic variance defined by PC1 and PC2. Species richness is highest in the Hajar and Dhofar Mountains, two of the most biodiverse areas of the Arabian Peninsula, and endemic species richness is greatest in the Jebel Akhdar, the highest part of the Hajar Mountains. Oman's 22 protected areas cover only 3.91% of the country, including within their limits 63.37% of terrestrial reptiles and 50% of all endemics. Our analyses show that large areas of the climatic space of Oman lie outside protected areas and that seven of the 20 climatic clusters are not protected at all. The results of the gap analysis indicate that most of the species are below the conservation target of 17% or even the less restrictive 12% of their total area within a protected area in order to be considered adequately protected. Therefore, an evaluation of the coverage of the current network of protected areas and the identification of priority protected areas for reptiles using reserve design algorithms are urgently needed. Our study also shows that more than half of the species are still pending of a definitive evaluation by the International Union for Conservation of Nature (IUCN).


Assuntos
Biodiversidade , Conservação dos Recursos Naturais/métodos , Répteis/classificação , Animais , Clima , Ecossistema , Omã
12.
Med Mycol ; 56(7): 838-846, 2018 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-29228361

RESUMO

An expanded library of matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) has been constructed using the spectra generated from 42 clinical isolates and 11 reference strains, including 23 different species from 8 sections (16 cryptic plus 7 noncryptic species). Out of a total of 379 strains of Aspergillus isolated from clinical samples, 179 strains were selected to be identified by sequencing of beta-tubulin or calmodulin genes. Protein spectra of 53 strains, cultured in liquid medium, were used to construct an in-house reference database in the MALDI-TOF MS. One hundred ninety strains (179 clinical isolates previously identified by sequencing and the 11 reference strains), cultured on solid medium, were blindy analyzed by the MALDI-TOF MS technology to validate the generated in-house reference database. A 100% correlation was obtained with both identification methods, gene sequencing and MALDI-TOF MS, and no discordant identification was obtained. The HUVR database provided species level (score of ≥2.0) identification in 165 isolates (86.84%) and for the remaining 25 (13.16%) a genus level identification (score between 1.7 and 2.0) was obtained. The routine MALDI-TOF MS analysis with the new database, was then challenged with 200 Aspergillus clinical isolates grown on solid medium in a prospective evaluation. A species identification was obtained in 191 strains (95.5%), and only nine strains (4.5%) could not be identified at the species level. Among the 200 strains, A. tubingensis was the only cryptic species identified. We demonstrated the feasibility and usefulness of the new HUVR database in MALDI-TOF MS by the use of a standardized procedure for the identification of Aspergillus clinical isolates, including cryptic species, grown either on solid or liquid media.

14.
Enferm. infecc. microbiol. clín. (Ed. impr.) ; 35(10): 638-644, dic. 2017. tab, graf, ilus
Artigo em Inglês | IBECS | ID: ibc-169563

RESUMO

Objective: The time to positivity (TTP) of blood cultures in patients with bloodstream infections (BSIs) has been considered to be a possible prognostic tool for some bacterial species. However, notable differences have been found between sampling designs and statistical methods in published studies to date, which makes it difficult to compare results or to derive reliable conclusions. Our objective was to evaluate the clinical and microbiological implications of TTP among patients with BSI caused by the most common pathogens. Methods: A total of 361 episodes of BSI were reported for 332 patients. The survival of the entire cohort was measured from the time of blood culture sampling. In order to compare our results with those of previous studies, TTP was divided in three different groups based on log rank (short TTP <12h; medium TTP ≥12h to ≤27h, and long TTP >27h). Cox proportional hazard models were used to calculate crude and adjusted hazard ratios (HR). Results: The Cox proportional hazard model revealed that TTP is an independent predictor of mortality (HR=1.00, p=0.031) in patients with BSIs. A higher mortality was found in the group of patients with the shortest TTP (<12h) (HR=2.100, p=0.047), as well as those with longest TTP (>27h) (HR=3.277, p=0.031). Conclusions: It seems that TTP may provide a useful prognostic tool associated with a higher risk of mortality, not only in patients with shorter TTP, but also in those with longer TTP (AU)


Objetivo: El tiempo de positividad (TP) de los hemocultivos en pacientes con bacteriemia ha sido considerado como una posible herramienta pronóstica. Sin embargo, en los estudios publicados hasta la fecha, hemos observado importantes diferencias tanto en el diseño experimental como en la metodología utilizada. Esto dificulta el poder comparar los resultados obtenidos u obtener conclusiones consistentes. El objetivo de este estudio ha sido evaluar las implicaciones clínicas y microbiológicas del TP en pacientes con bacteriemia causada por los microorganismos más frecuentes, revisando la metodología utilizada en estudios anteriores. Métodos: Se estudiaron un total de 361 episodios de bacteriemia de 332 pacientes. La supervivencia de nuestra cohorte se midió desde que se tomó la muestra de hemocultivo. El TP fue dividido en tres grupos en base al log rank (TP cortos <12h; TP medios ≥12h y ≤27h; TP largos >27h), con el objetivo de comparar nuestros resultados con los obtenidos en estudios previos. Se utilizó el modelo de riesgos proporcionales (Cox) para calcular los hazard ratios (HR) tanto crudos como ajustados. Resultados: El modelo Cox mostró que el TP es un factor independiente relacionado con la mortalidad en pacientes con bacteriemia (HR = 1,00, p = 0,031). Concretamente, encontramos una mayor mortalidad en aquellos pacientes con TP cortos (<12 horas) (HR=2.100, p=0,047), así como en pacientes con TP largos (>27h) (HR=3.277, p=0,031). Conclusiones: En el presente estudio demostramos que el TP puede ser utilizado como una herramienta pronóstica útil de mortalidad no solo en pacientes con TP cortos, sino también en aquellos con TP largos (AU)


Assuntos
Humanos , Bacteriemia/diagnóstico , Bacteriemia/microbiologia , Hemocultura/métodos , Prognóstico , Sensibilidade e Especificidade , Técnicas Microbiológicas/métodos , Estudos Prospectivos , Análise Estatística , Estimativa de Kaplan-Meier , Análise Multivariada , Bibliometria
15.
J Med Microbiol ; 66(6): 713-720, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28598305

RESUMO

PURPOSE: The aim of this study was to compare the in vitro activity of ampicillin and moxifloxacin against six isolates selected from 154 invasive clinical isolates of Listeria monocytogenes and evaluate their intra- and extracellular activities with achievable central nervous system concentrations obtained using Monte Carlo simulations with conventional and unconventional dosages. METHODOLOGY: The MICs and minimal bactericidal concentrations (MBCs) of ampicillin and moxifloxacin were determined by using the broth microdilution method. The intra- and extracellular activities were compared using time-kill curves and inhibition of intracellular growth assays. RESULTS: The MICs50/90 of ampicillin were 0.125/0.5 mg l-1 and the MBC50/90 was ≥16 mg l-1, while the moxifloxacin MICs50/90 were 0.25/0.5 mg l-1 and the MBC50/90 was 0.5 mg l-1. Ampicillin did not show any extracellular bactericidal activity at 24 h, although bactericidal activity was detected at 48 h. For moxifloxacin, the bactericidal effect was evident after 6 h of incubation. Both antibiotics achieved significant reductions in intracellular inoculum after 1-24 h of incubation; however, moxifloxacin becomes bactericidal more rapidly, producing a much greater reduction in the inoculum in the first hour than ampicillin. There were no differences among the MIC and MBC values of moxifloxacin and ampicillin among the strains belonging to different serotypes and/or epidemic clones. This fact was also found in the intra- and extracellular studies. CONCLUSION: The results of this study demonstrated the faster bactericidal activity of moxifloxacin at achievable central nervous system concentrations against intra- and extracellular forms of L. monocytogenes in comparison with ampicillin.


Assuntos
Ampicilina/farmacologia , Antibacterianos/farmacologia , Fluoroquinolonas/farmacologia , Listeria monocytogenes/efeitos dos fármacos , Células A549 , Ampicilina/líquido cefalorraquidiano , Antibacterianos/líquido cefalorraquidiano , Sistema Nervoso Central , Simulação por Computador , Humanos , Listeria monocytogenes/crescimento & desenvolvimento , Listeriose/microbiologia , Testes de Sensibilidade Microbiana , Método de Monte Carlo , Moxifloxacina
16.
Enferm Infecc Microbiol Clin ; 35(10): 638-644, 2017 Dec.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-27916290

RESUMO

OBJECTIVE: The time to positivity (TTP) of blood cultures in patients with bloodstream infections (BSIs) has been considered to be a possible prognostic tool for some bacterial species. However, notable differences have been found between sampling designs and statistical methods in published studies to date, which makes it difficult to compare results or to derive reliable conclusions. Our objective was to evaluate the clinical and microbiological implications of TTP among patients with BSI caused by the most common pathogens. METHODS: A total of 361 episodes of BSI were reported for 332 patients. The survival of the entire cohort was measured from the time of blood culture sampling. In order to compare our results with those of previous studies, TTP was divided in three different groups based on log rank (short TTP <12h; medium TTP ≥12h to ≤27h, and long TTP >27h). Cox proportional hazard models were used to calculate crude and adjusted hazard ratios (HR). RESULTS: The Cox proportional hazard model revealed that TTP is an independent predictor of mortality (HR=1.00, p=0.031) in patients with BSIs. A higher mortality was found in the group of patients with the shortest TTP (<12h) (HR=2.100, p=0.047), as well as those with longest TTP (>27h) (HR=3.277, p=0.031). CONCLUSIONS: It seems that TTP may provide a useful prognostic tool associated with a higher risk of mortality, not only in patients with shorter TTP, but also in those with longer TTP.

17.
PLoS One ; 11(12): e0168468, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27992528

RESUMO

OBJECTIVES: This study aims to analyze the mortality and the length of ICU stay (LOS) of A. baumannii VAP compared to respiratory colonization in patients with mechanical ventilation (MV). METHODS: A prospective cohort study was performed in an ICU of adult patients (February 2010-June 2011). One hundred patients on MV with A. baumannii in lower respiratory airways were recruited, and classified as VAP or airways colonization according to CPIS criteria, with a punctuation ≥6. LOS, 30-days mortality, A. baumannii bacteremia, and clinical features including antibiotic therapy were recorded. Multivariate analysis (linear and Cox regression) and survival analysis (Kaplan-Meier curves) were performed. RESULTS: Fifty-seven VAP and 43 colonized A. baumannii patients were analyzed. Among the A. baumannii strains, 99% were non-susceptible to carbapenems and the MIC90 of colistin was 0.12 mg/l. Therapy was appropriate in 94.6% of VAP patients, most of them with colistin 6 MIU/day, although in 13 (23.6%) cases colistin was started 48 hours after the onset of VAP. Mortality was similar in both groups (VAP 24.6% vs. colonized 27.9%, p = 0.7). Bacteremia and acute kidney insufficiency were associated with decreased survival (p = 0.02 and p = 0.04, respectively) in VAP patients. LOS was 21.5 (11.5-42.75) vs. 9 (6-22) days for VAP and colonized patients (p = 0.004). VAP (p = 0.003) and age (p = 0.01) were independently related to a longer LOS. CONCLUSIONS: Multidrug-resistant A. baumannii VAP treated with colistin does not have a different mortality compared to lower airways colonization, among patients on mechanical-ventilation, in a setting of high susceptibility to colistin of A. baumannii.


Assuntos
Acinetobacter baumannii/metabolismo , Bacteriemia , Carbapenêmicos , Colistina/administração & dosagem , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Adulto , Bacteriemia/tratamento farmacológico , Bacteriemia/microbiologia , Bacteriemia/mortalidade , Intervalo Livre de Doença , Feminino , Seguimentos , Humanos , Masculino , Pneumonia Associada à Ventilação Mecânica/tratamento farmacológico , Pneumonia Associada à Ventilação Mecânica/microbiologia , Pneumonia Associada à Ventilação Mecânica/mortalidade , Estudos Prospectivos , Taxa de Sobrevida
18.
Enferm. infecc. microbiol. clín. (Ed. impr.) ; 34(10): 645-651, dic. 2016. ilus, tab
Artigo em Inglês | IBECS | ID: ibc-158737

RESUMO

Objective: To investigate a Serratia marcescens (S. marcescens) outbreak in a Neonatal Unit in a tertiary university hospital. Methods: Descriptive study of children admitted to the Unit with S. marcescens infection from November 2012 to March 2013. Conventional microbiological methods for clinical and environmental samples were used. The clonal relationship between all available isolates was established by molecular methods. A multidisciplinary team was formed, and preventive measures were taken. Results: S. marcescens was isolated from 18 children. The overall attack rate was 12%, and the case fatality rate in the Intensive Care Unit was 23.5%. The most prevalent types of infections were pneumonia (6), conjunctivitis (6), and bloodstream infection (5). Clinical isolates and environmental isolates obtained from an incubator belonged to a unique clone. The clonal relationship between all S. marcescens strains helped us to identify the possible source of the outbreak. Conclusion: Isolation of S. marcescens from stored water in a container, and from the surface of an incubator after cleaning, suggests a possible environmental source as the outbreak origin, which has been perpetuated due to a failure of cleaning methods in the Unit. The strict hygiene and cleaning measures were the main factors that contributed to the end of the outbreak (AU)


Objetivo: Investigar un brote por Serratia marcescens (S. marcescens) en una unidad de neonatología en un hospital universitario de tercer nivel. Método: Estudio descriptivo de los pacientes ingresados en la Unidad de noviembre de 2012 a marzo de 2013. Se usaron métodos microbiológicos convencionales de muestras clínicas y ambientales. La relación clonal de los aislados disponibles se llevó a cabo mediante estudio molecular. Se formó un equipo multidisciplinar a partir del cual se tomaron las medidas preventivas. Resultados: Se aisló S. marcescens en 18 niños. La tasa global de ataque fue del 12% y la letalidad en la Unidad de Cuidados Intensivos llegó al 23,5%. Los tipos de infección más frecuentes fueron la neumonía (6), conjuntivitis (6) y bacteriemia (5). Tanto las muestras clínicas como las ambientales obtenidas de una incubadora pertenecían a un único clon. La relación clonal entre todas las cepas de S. marcescens permitió identificar la posible fuente de infección del brote. Conclusión: El aislamiento de S. marcescens en agua almacenada en un contenedor y en la superficie de una incubadora tras su limpieza sugiere una posible fuente ambiental como el origen del brote, perpetuado por fallos en los métodos de limpieza en la Unidad. El cumplimiento estricto de la higiene de manos y mejora en la limpieza fueron los principales factores que contribuyeron a la finalización del brote (AU)


Assuntos
Humanos , Masculino , Feminino , Recém-Nascido , Lactente , Serratia marcescens/patogenicidade , Infecções por Serratia/epidemiologia , Infecção Hospitalar/epidemiologia , Microbiologia da Água , Unidades de Terapia Intensiva Neonatal/estatística & dados numéricos , Poluição da Água/análise , Surtos de Doenças/estatística & dados numéricos
20.
Antimicrob Agents Chemother ; 60(7): 4252-8, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27139482

RESUMO

Escherichia coli isolates carrying chromosomally encoded low-level-quinolone-resistant (LLQR) determinants are frequently found in urinary tract infections (UTIs). LLQR mutations are considered the first step in the evolutionary pathway producing high-level fluoroquinolone resistance. Therefore, their evolution and dissemination might influence the outcome of fluoroquinolone treatments of UTI. Previous studies support the notion that low urine pH decreases susceptibility to ciprofloxacin (CIP) in E. coli However, the effect of the urinary tract physiological parameters on the activity of ciprofloxacin against LLQR E. coli strains has received little attention. We have studied the activity of ciprofloxacin under physiological urinary tract conditions against a set of well-characterized isogenic E. coli derivatives carrying the most prevalent chromosomal mutations (ΔmarR, gyrA-S83L, gyrA-D87N, and parC-S80R and some combinations). The results presented here demonstrate that all the LLQR strains studied became resistant to ciprofloxacin (according to CLSI guidelines) under physiological conditions whereas the control strain lacking LLQR mutations did not. Moreover, the survival of some LLQR E. coli variants increased up to 100-fold after challenge with a high concentration of ciprofloxacin under UTI conditions compared to the results seen with Mueller-Hinton broth. These selective conditions could explain the high prevalence of LLQR mutations in E. coli Furthermore, our data strongly suggest that recommended methods for MIC determination produce poor estimations of CIP activity against LLQR E. coli in UTIs.


Assuntos
Antibacterianos/uso terapêutico , Ciprofloxacino/uso terapêutico , Quinolonas/uso terapêutico , Infecções Urinárias/tratamento farmacológico , Infecções Urinárias/urina , Farmacorresistência Bacteriana/genética , Escherichia coli/efeitos dos fármacos , Escherichia coli/patogenicidade , Infecções por Escherichia coli/tratamento farmacológico , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/urina , Fluoroquinolonas/uso terapêutico , Genótipo , Voluntários Saudáveis , Humanos , Concentração de Íons de Hidrogênio , Testes de Sensibilidade Microbiana , Mutação/genética , Estudos Prospectivos , Infecções Urinárias/microbiologia
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