RESUMEN
BACKGROUND: Restrictive lung disease leading to abnormal lung function in kidney transplant recipients is commonly associated with noninfectious complications or medications used for post-transplant immunosuppression. Herein, we report an interesting case of pediatric kidney transplant recipient with weight loss and abnormal spirometry who was diagnosed to have late-onset Pneumocystis pneumonia. CASE REPORT: A 17-year-old male patient with a history of allergic rhinitis, mild persistent asthma, and deceased donor kidney transplant, performed 18 months prior, presented for routine evaluation of his asthma to the pulmonology clinic. He was clinically asymptomatic except for a weight loss of 8 kg over 6-month period prior to presentation. Patient's spirometry was suggestive of a restrictive pattern and further investigation using a high-resolution computed tomography (HRCT) of the chest showed bilateral diffuse ground-glass reticulonodular opacities with subpleural sparing suggestive of interstitial pneumonitis. A bronchoscopy with bronchoalveolar lavage revealed organisms consistent with Pneumocystis jirovecii on gomori-methenamine-silver (GMS) staining. Beta-d-glucan testing in serum revealed a level of >500 pg/mL (normal 0-59 pg/mL) further supportive of Pneumocystis jirovecii infection. Patient was treated with a 6-week course of trimethoprim-sulfamethoxazole. His weight loss and beta-d-glucan levels improved over a course of 6 months, and he continues to be on trimethoprim-sulfamethoxazole prophylaxis. CONCLUSION: Late-onset Pneumocystis jirovecii infection in kidney transplant recipients can have an atypical presentation. Treating physicians should consider PJP in the differential diagnosis of unexplained weight loss in pediatric kidney transplant recipients, especially those receiving a large cumulative burden of immunosuppression.
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Trasplante de Riñón , Pneumocystis carinii , Neumonía por Pneumocystis , Masculino , Humanos , Niño , Adolescente , Neumonía por Pneumocystis/diagnóstico , Neumonía por Pneumocystis/tratamiento farmacológico , Neumonía por Pneumocystis/etiología , Combinación Trimetoprim y Sulfametoxazol/uso terapéutico , Trasplante de Riñón/efectos adversos , Terapia de Inmunosupresión/efectos adversosRESUMEN
Bacteremia can progress to septic shock and death without appropriate medical intervention. Increasing evidence supports the role of molecular diagnostic panels in reducing the clinical impact of these infections through rapid identification of the infecting organism and associated antimicrobial resistance genes. We report the results of a multicenter clinical study assessing the performance of the GenMark Dx ePlex investigational-use-only blood culture identification Gram-negative panel (BCID-GN), a rapid diagnostic assay for detection of bloodstream pathogens in positive blood culture (PBC) bottles. Prospective, retrospective, and contrived samples were tested. Results from the BCID-GN were compared to standard-of-care bacterial identification methods. Antimicrobial resistance genes (ARGs) were identified using PCR and sequence analysis. The final BCID-GN analysis included 2,444 PBC samples, of which 926 were clinical samples with negative Gram stain results. Of these, 109 samples had false-negative and/or -positive results, resulting in an overall sample accuracy of 88.2% (817/926). After discordant resolution, overall sample accuracy increased to 92.9% (860/926). Pre- and postdiscordant resolution sample accuracy excludes 37 Gram-negative organisms representing 20 uncommon genera, 10 Gram-positive organisms, and 1 Candida species present in 5% of samples that are not targeted by the BCID-GN. The overall weighted positive percent agreement (PPA), which averages the individual PPAs from the 27 targets (Gram-negative and ARG), was 94.9%. The limit of detection ranged from 104 to 107 CFU/ml, except for one strain of Fusobacterium necrophorum at 108 CFU/ml.
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Bacteriemia , Cultivo de Sangre , Bacteriemia/diagnóstico , Bacterias Gramnegativas/genética , Humanos , Reacción en Cadena de la Polimerasa , Estudios Prospectivos , Estudios RetrospectivosRESUMEN
We describe 9 patients at a medical center in Detroit, Michigan, USA, with severe acute respiratory syndrome coronavirus 2 and Clostridioides difficile. Both infections can manifest as digestive symptoms and merit screening when assessing patients with diarrhea during the coronavirus disease pandemic. These co-infections also highlight the continued importance of antimicrobial stewardship.
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Betacoronavirus , Clostridioides difficile , Infecciones por Clostridium/epidemiología , Coinfección/epidemiología , Infecciones por Coronavirus/epidemiología , Neumonía Viral/epidemiología , Adulto , Anciano , Antibacterianos/efectos adversos , Programas de Optimización del Uso de los Antimicrobianos , COVID-19 , Infecciones por Clostridium/inducido químicamente , Infecciones por Clostridium/microbiología , Coinfección/microbiología , Infecciones por Coronavirus/microbiología , Femenino , Humanos , Masculino , Michigan/epidemiología , Persona de Mediana Edad , Pandemias , Neumonía Viral/microbiología , Vigilancia de la Población , SARS-CoV-2RESUMEN
Clostridioides difficile is the leading cause of diarrhea in hospitalized U.S. patients and results in over 400,000 cases of C. difficile infection per year. C. difficile infections have mortality rates of 6 to 30% and significantly increase health care costs, because of increased length of stay and increased frequency of readmissions due to recurrences. Efforts to reduce the spread of C. difficile in hospitals have led to the development of rapid sensitive diagnostic methods. A multicenter study was performed to establish the performance characteristics of the Revogene C. difficile test (Meridian Bioscience, Cincinnati, OH, USA) for use in detection of the toxin B (tcdB) gene from toxigenic C. difficile The Revogene instrument is a new molecular platform that uses real-time PCR to detect nucleic acids in up to 8 specimens at a time. A total of 2,461 specimens from symptomatic patients that had been submitted for C. difficile testing were enrolled at 7 sites throughout the United States and Canada for evaluation of the assay. Each stool specimen was tested for the presence of the tcdB gene using the Revogene C. difficile test, and results were compared with those of the reference method, a combination of direct and enriched culture methods. Overall, the Revogene C. difficile test demonstrated a sensitivity of 85.0% (95% confidence interval, 80% to 88%) and a specificity of 97.2% (95% confidence interval, 96% to 98%). The Revogene C. difficile test, using clinical stool specimens for detection of tcdB in C. difficile, demonstrated acceptable sensitivity and specificity, with a short turnaround time.
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Proteínas Bacterianas/genética , Toxinas Bacterianas/genética , Clostridioides difficile/genética , Infecciones por Clostridium/diagnóstico , Heces/microbiología , Técnicas de Diagnóstico Molecular/métodos , Adolescente , Adulto , Canadá , Niño , Preescolar , Infecciones por Clostridium/microbiología , Diarrea/microbiología , Humanos , Lactante , Persona de Mediana Edad , Estudios Retrospectivos , Sensibilidad y Especificidad , Estados Unidos , Adulto JovenRESUMEN
Background: Clostridium difficile (CD) is often classified as a healthcare-associated infection (HAI) and a hospital-acquired condition (HAC) in the hospital setting. However, pediatric oncology patients comprise a significant portion of Clostridium difficile infections (CDI), with hematopoietic stem cell transplant (HSCT) recipients constituting a major subset of this group due to unique, non-modifiable risk factors. We evaluated patterns of clostridium difficile infections at our institution to provide an accurate evaluation of the vulnerability of pediatric oncology and HSCT patients to clostridium difficile infections in comparison to the general pediatric population and underscore the non-tenability of classifying clostridium difficile infections as a hospital-acquired condition in HSCT patients. Methods: Single-center retrospective review of all clostridium difficile stool tests performed over an 11-year period; data analyzed and statistical comparisons performed between patient groups. Results: 5271 total samples were obtained during the study time period from 3127 patients. At least one positive test result was found in 18.6% of patients. Oncology and HSCT patients (38.2%) were more likely to have a positive test result than hematology (17.5%) and other patients (16.8%) (p < 0.001). Sixty-percent of patients who underwent HSCT were tested during this time frame. Of those, 39.3% had a positive test result and 48.5% of those patients went on to have a subsequent infection that met the criteria to be defined as recurrent. Conclusions: The high incidence rate and frequency of recurrence underscores the current near-inevitable nature of clostridium difficile infections in oncology and HSCT patients. We conclude that a blanket designation of clostridium difficile infections as an hospital-acquired condition is therefore questionable in this population.
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Clostridioides difficile , Infecciones por Clostridium/epidemiología , Trasplante de Células Madre Hematopoyéticas , Neoplasias/epidemiología , Neoplasias/terapia , Adolescente , Aloinjertos , Niño , Preescolar , Femenino , Humanos , Masculino , Estudios RetrospectivosRESUMEN
Strategies are needed to improve time to optimal therapy in patients with bloodstream infections (BSI) due to resistant Gram-negative (GN) pathogens. Accelerate Pheno (ACC) can provide antimicrobial susceptibility results within 7 h of a positive culture and may more rapidly optimize therapy. The primary objective of this study was to evaluate the hypothetical impact of ACC on time to effective therapy (TTET) and time to definitive therapy (TTDT) among patients with BSI due to resistant GN pathogens. ACC was performed on resistant GN BSI isolates, and results were not available to clinicians in real time. A potential benefit of having ACC on TTET or TTDT was determined if modifications to antimicrobial regimens could have been made sooner with ACC. Comparisons on the impact of ACC in the presence or absence of testing by the Verigene Gram-negative blood culture test (Verigene GN-BC) were performed. Sixty-one patients with resistant GN BSI were evaluated. The median actual TTET and TTDT in the cohort were 25.9 h (interquartile range [IQR], 18.5, 42.1) and 47.6 h (IQR, 24.9, 79.6), respectively. Almost half of the patients had potential improvement in TTET and/or TTDT with ACC. In patients who would have had a benefit the median potential decreases in TTET and TTDT were 16.6 h (IQR, 5.5 to 30.6) and 29.8 h (IQR, 13.6 to 43), respectively. The largest potential improvements were seen in patients for whom Verigene results were not available. In conclusion, among patients with resistant GN BSI in a setting where other rapid diagnostic technologies are utilized, ACC results could have further improved TTET and TTDT.
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Bacteriemia/tratamiento farmacológico , Pruebas Diagnósticas de Rutina/métodos , Infecciones por Bacterias Gramnegativas/tratamiento farmacológico , Pruebas de Sensibilidad Microbiana/métodos , Tiempo de Tratamiento , Programas de Optimización del Uso de los Antimicrobianos/métodos , Cultivo de Sangre , Femenino , Bacterias Gramnegativas/clasificación , Bacterias Gramnegativas/efectos de los fármacos , Humanos , Masculino , Persona de Mediana Edad , Estudios RetrospectivosRESUMEN
Background: Rapid organism identification and antimicrobial susceptibility testing (AST) can optimize antimicrobial therapy in patients with bacteraemia. The Accelerate Pheno™ system (ACC) can provide identification and AST results within 7 h of a positive culture. Objectives: To assess the hypothetical impact of ACC on time to effective therapy (TTET), time to definitive therapy (TTDT) and antimicrobial usage at the Detroit Medical Center (DMC). Methods: Patients with positive blood cultures from 29 March to 24 June 2016 were included. ACC was performed in parallel with normal laboratory procedures, but results were not made available to the clinicians. The potential benefit of having ACC results was determined if clinicians modified therapy based on actual AST results. Potential changes in TTET, TTDT and antibiotic usage were calculated. Results: One hundred and sixty-seven patients were included. The median TTET was 2.4 h (IQR 0.5, 15.1). Had ACC results been available, TTET could have been improved in four patients (2.4%), by a median decrease of 18.9 h (IQR 11.3, 20.4). The median TTDT was 41.4 h (IQR 21.7, 73.3) and ACC results could have improved TTDT among 51 patients (30.5%), by a median decrease of 25.4 h (IQR 18.7, 37.5). ACC implementation could have led to decreases in usage of cefepime (16% reduction), aminoglycosides (23%), piperacillin/tazobactam (8%) and vancomycin (4%). Conclusions: ACC results could potentially improve time to de-escalation and reduce use of antimicrobials. The impact of ACC on TTET was small, likely related to the availability of other rapid diagnostic tests at DMC.
Asunto(s)
Antibacterianos/farmacología , Programas de Optimización del Uso de los Antimicrobianos/métodos , Farmacorresistencia Bacteriana Múltiple , Bacterias Gramnegativas/efectos de los fármacos , Infecciones por Bacterias Gramnegativas/tratamiento farmacológico , Tiempo de Tratamiento/estadística & datos numéricos , Adulto , Anciano , Antibacterianos/uso terapéutico , Programas de Optimización del Uso de los Antimicrobianos/normas , Cultivo de Sangre/estadística & datos numéricos , Femenino , Genotipo , Infecciones por Bacterias Gramnegativas/diagnóstico , Infecciones por Bacterias Gramnegativas/microbiología , Humanos , Hibridación Fluorescente in Situ/métodos , Hibridación Fluorescente in Situ/normas , Masculino , Pruebas de Sensibilidad Microbiana/métodos , Pruebas de Sensibilidad Microbiana/normas , Persona de Mediana Edad , Estudios Retrospectivos , Sepsis/diagnóstico , Sepsis/tratamiento farmacológico , Sepsis/microbiologíaRESUMEN
Rapid diagnostic tests (RDTs) have revolutionized the management of Gram-negative bacteremia by allowing antimicrobial stewardship teams the ability to escalate therapy and improve patient outcomes through timely organism identification and detection of certain resistance determinants. However, given the complex nature of Gram-negative resistance, stewardship teams are left without clear direction for how to respond when resistance determinants are absent, as the safety of de-escalation in this setting is unknown. The primary purpose of this analysis was to determine the negative predictive values (NPVs) of resistance marker absence for predicting susceptibility in target bug-drug scenarios at two geographically distinct institutions. A total of 1,046 Gram-negative bloodstream isolates that were analyzed with the Verigene BC-GN platform were assessed. Except for Pseudomonas aeruginosa, the absence of resistance determinants as reported by the RDT largely predicted susceptibility to target antibiotics at both institutions. NPVs for ceftriaxone susceptibility in Escherichia coli and Klebsiella pneumoniae in the absence of either CTX-M or a carbapenemase gene were 98% and 93 to 94%, respectively. Similar results were seen with other target bug-drug scenarios, with NPVs of 94 to 100% demonstrated at both institutions, with the exception of P. aeruginosa, for which NPVs were poor, likely due to the more complex nature of resistance in this pathogen. The results of this study show that clinicians at both institutions should have confidence in de-escalation in the absence of resistance determinant detection by Verigene BC-GN testing, and the methodology described within this article can serve as a blueprint for other stewardship programs to employ at their institutions to optimize management of Gram-negative bacteremia.
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Programas de Optimización del Uso de los Antimicrobianos/métodos , Bacteriemia/microbiología , Bacteriemia/tratamiento farmacológico , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Escherichia coli/efectos de los fármacos , Escherichia coli/patogenicidad , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Gramnegativas/metabolismo , Bacterias Gramnegativas/patogenicidad , Infecciones por Bacterias Gramnegativas/tratamiento farmacológico , Infecciones por Bacterias Gramnegativas/microbiología , Humanos , Pseudomonas aeruginosa/efectos de los fármacos , Pseudomonas aeruginosa/patogenicidad , beta-Lactamasas/genética , beta-Lactamasas/metabolismoRESUMEN
Clostridium difficile is a leading cause of infectious diarrhea in hematopoietic stem cell transplant (HSCT) recipients. Asymptomatic colonization of the gastrointestinal tract occurs before development of C. difficile infection (CDI). This prospective study examines the rates, risk factors, and outcomes of colonization with toxigenic and nontoxigenic strains of C. difficile in HSCT patients. This 18-month study was conducted in the HSCT unit at the Karmanos Cancer Center and Wayne State University in Detroit. Stool samples from the patients who consented for the study were taken at admission and weekly until discharge. Anaerobic culture for C. difficile and identification of toxigenic strains by PCR were performed on the stool samples. Demographic information and clinical and laboratory data were collected. Of the 150 patients included in the study, 29% were colonized with C. difficile at admission; 12% with a toxigenic strain and 17% with a nontoxigenic strain. Over a 90-day follow-up, 12 of 44 (26%) patients colonized with any C. difficile strain at admission developed CDI compared with 13 of 106 (12%) of patients not colonized (odds ratio [OR], 2.70; 95% confidence interval [95% CI], 1.11 to 6.48; P = .025). Eleven of 18 (61%) patients colonized with the toxigenic strain and 1 of 26 (4%) of those colonized with nontoxigenic strain developed CDI (OR, 39.30; 95% CI, 4.30 to 359.0; P < .001) at a median of 12 days. On univariate and multivariate analyses, none of the traditional factors associated with high risk for C. difficile colonization or CDI were found to be significant. Recurrent CDI occurred in 28% of cases. Asymptomatic colonization with C. difficile at admission was high in our HSCT population. Colonization with toxigenic C. difficile was predictive of CDI, whereas colonization with a nontoxigenic C. difficile appeared protective. These findings may have implications for infection control strategies and for novel approaches for the prevention and preemptive treatment of CDI in the HSCT patient population.
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Clostridioides difficile , Diarrea , Enterocolitis Seudomembranosa , Adulto , Anciano , Aloinjertos , Clostridioides difficile/genética , Clostridioides difficile/aislamiento & purificación , Clostridioides difficile/patogenicidad , Diarrea/etiología , Diarrea/genética , Diarrea/microbiología , Enterocolitis Seudomembranosa/etiología , Enterocolitis Seudomembranosa/genética , Enterocolitis Seudomembranosa/microbiología , Femenino , Estudios de Seguimiento , Trasplante de Células Madre Hematopoyéticas , Humanos , Masculino , Persona de Mediana Edad , Estudios ProspectivosRESUMEN
Sepsis is a major cause of morbidity, mortality, and increased medical expense. Rapid diagnosis improves outcomes and reduces costs. The FilmArray blood culture identification panel (BioFire Diagnostics LLC, Salt Lake City, UT), a highly multiplexed PCR assay, can identify 24 etiologic agents of sepsis (8 Gram-positive, 11 Gram-negative, and 5 yeast species) and three antimicrobial resistance genes (mecA, vanA/B, and blaKPC) from positive blood culture bottles. It provides results in about 1 h with 2 min for assay setup. We present the results of an eight-center trial comparing the sensitivity and specificity of the panel with those of the laboratories' standard phenotypic identification techniques, as well as with molecular methods used to distinguish Acinetobacter baumannii from other members of the A. calcoaceticus-A. baumannii complex and to detect antimicrobial resistance genes. Testing included 2,207 positive aerobic blood culture samples, 1,568 clinical and 639 seeded. Samples were tested fresh or were frozen for later testing within 8 h after the bottles were flagged as positive by an automated blood culture system. At least one organism was detected by the panel in 1,382 (88.1%) of the positive clinical specimens. The others contained primarily off-panel organisms. The panel reported multiple organisms in 81 (5.86%) positive clinical specimens. The unresolved blood culture identification sensitivity for all target detections exceeded 96%, except for Klebsiella oxytoca (92.2%), which achieved 98.3% sensitivity after resolution of an unavoidable phenotypic error. The sensitivity and specificity for vanA/B and blaKPC were 100%; those for mecA were 98.4 and 98.3%, respectively.
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Bacterias/clasificación , Bacterias/genética , Reacción en Cadena de la Polimerasa Multiplex , Sepsis/diagnóstico , Sepsis/microbiología , Levaduras/clasificación , Levaduras/genética , Bacterias/efectos de los fármacos , Farmacorresistencia Bacteriana , Farmacorresistencia Fúngica , Genes Bacterianos , Genes Fúngicos , Humanos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Levaduras/efectos de los fármacosRESUMEN
Rapid diagnosis and treatment of infectious meningitis and encephalitis are critical to minimize morbidity and mortality. Comprehensive testing of cerebrospinal fluid (CSF) often includes Gram stain, culture, antigen detection, and molecular methods, paired with chemical and cellular analyses. These methods may lack sensitivity or specificity, can take several days, and require significant volume for complete analysis. The FilmArray Meningitis/Encephalitis (ME) Panel is a multiplexed in vitro diagnostic test for the simultaneous, rapid (â¼1-h) detection of 14 pathogens directly from CSF specimens: Escherichia coli K1, Haemophilus influenzae, Listeria monocytogenes, Neisseria meningitidis, Streptococcus pneumoniae, Streptococcus agalactiae, cytomegalovirus, enterovirus, herpes simplex virus 1 and 2, human herpesvirus 6, human parechovirus, varicella-zoster virus, and Cryptococcus neoformans/Cryptococcus gattii We describe a multicenter evaluation of 1,560 prospectively collected CSF specimens with performance compared to culture (bacterial analytes) and PCR (all other analytes). The FilmArray ME Panel demonstrated a sensitivity or positive percentage of agreement of 100% for 9 of 14 analytes. Enterovirus and human herpesvirus type 6 had agreements of 95.7% and 85.7%, and L. monocytogenes and N. meningitidis were not observed in the study. For S. agalactiae, there was a single false-positive and false-negative result each, for a sensitivity and specificity of 0 and 99.9%, respectively. The specificity or negative percentage of agreement was 99.2% or greater for all other analytes. The FilmArray ME Panel is a sensitive and specific test to aid in diagnosis of ME. With use of this comprehensive and rapid test, improved patient outcomes and antimicrobial stewardship are anticipated.
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Líquido Cefalorraquídeo/microbiología , Líquido Cefalorraquídeo/virología , Encefalitis/diagnóstico , Meningitis/diagnóstico , Técnicas de Diagnóstico Molecular/métodos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Bacterias/clasificación , Bacterias/aislamiento & purificación , Infecciones Bacterianas/diagnóstico , Infecciones Bacterianas/microbiología , Infecciones Fúngicas del Sistema Nervioso Central/diagnóstico , Infecciones Fúngicas del Sistema Nervioso Central/microbiología , Niño , Preescolar , Encefalitis/etiología , Femenino , Hongos/clasificación , Hongos/aislamiento & purificación , Humanos , Lactante , Recién Nacido , Masculino , Meningitis/etiología , Persona de Mediana Edad , Estudios Prospectivos , Sensibilidad y Especificidad , Factores de Tiempo , Virosis/diagnóstico , Virosis/virología , Virus/clasificación , Virus/aislamiento & purificación , Adulto JovenAsunto(s)
Proteínas Bacterianas/genética , Escherichia coli/genética , Klebsiella pneumoniae/genética , beta-Lactamasas/genética , Adulto , Carbapenémicos/farmacología , Escherichia coli/aislamiento & purificación , Genes Bacterianos , Humanos , Klebsiella pneumoniae/aislamiento & purificación , Masculino , Técnicas de Diagnóstico Molecular/métodos , Mutación , Reacción en Cadena de la PolimerasaRESUMEN
Candida species are common causes of bloodstream infections (BSI), with high mortality. Four species cause >90% of Candida BSI: C. albicans, C. glabrata, C. parapsilosis, and C. tropicalis. Differentiation of Candida spp. is important because of differences in virulence and antimicrobial susceptibility. Candida QuickFISH BC, a multicolor, qualitative nucleic acid hybridization assay for the identification of C. albicans (green fluorescence), C. glabrata (red fluorescence), and C. parapsilosis (yellow fluorescence), was tested on Bactec and BacT/Alert blood culture bottles which signaled positive on automated blood culture devices and were positive for yeast by Gram stain at seven study sites. The results were compared to conventional identification. A total of 419 yeast-positive blood culture bottles were studied, consisting of 258 clinical samples (89 C. glabrata, 79 C. albicans, 23 C. parapsilosis, 18 C. tropicalis, and 49 other species) and 161 contrived samples inoculated with clinical isolates (40 C. glabrata, 46 C. albicans, 36 C. parapsilosis, 19 C. tropicalis, and 20 other species). A total of 415 samples contained a single fungal species, with C. glabrata (n = 129; 30.8%) being the most common isolate, followed by C. albicans (n = 125; 29.8%), C. parapsilosis (n = 59; 14.1%), C. tropicalis (n = 37; 8.8%), and C. krusei (n = 17; 4.1%). The overall agreement (with range for the three major Candida species) between the two methods was 99.3% (98.3 to 100%), with a sensitivity of 99.7% (98.3 to 100%) and a specificity of 98.0% (99.4 to 100%). This study showed that Candida QuickFISH BC is a rapid and accurate method for identifying C. albicans, C. glabrata, and C. parapsilosis, the three most common Candida species causing BSI, directly from blood culture bottles.
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Sangre/microbiología , Candida/clasificación , Candida/aislamiento & purificación , Candidemia/diagnóstico , Candidemia/microbiología , Hibridación Fluorescente in Situ/métodos , Técnicas Microbiológicas/métodos , Técnicas de Diagnóstico Molecular/métodos , Candida/genética , Humanos , Sensibilidad y EspecificidadAsunto(s)
Complicaciones Infecciosas del Embarazo/diagnóstico , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos , Infecciones Estreptocócicas/diagnóstico , Streptococcus agalactiae/crecimiento & desarrollo , Adulto , Cultivo de Sangre , Centers for Disease Control and Prevention, U.S. , Medios de Cultivo/química , Femenino , Humanos , Embarazo , Complicaciones Infecciosas del Embarazo/microbiología , Sensibilidad y Especificidad , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/normas , Infecciones Estreptocócicas/microbiología , Streptococcus agalactiae/genética , Streptococcus agalactiae/aislamiento & purificación , Estados Unidos , Vagina/microbiologíaRESUMEN
Tigecycline is one of the few remaining therapeutic options for extensively drug-resistant (XDR) Gram-negative bacilli (GNB). MICs of tigecycline to Acinetobacter baumannii have been reported to be elevated when determined by the Etest compared to determinations by the broth microdilution (BMD) method. The study aim was to compare the susceptibility of GNB to tigecycline by four different testing methods. GNB were collected from six health care systems (25 hospitals) in southeast Michigan from January 2010 to September 2011. Tigecycline MICs among A. baumannii, carbapenem-resistant Enterobacteriaceae (CRE), extended-spectrum ß-lactamase (ESBL)-producing Enterobacteriaceae, and susceptible Enterobacteriaceae isolates were determined by Etest, BMD, Vitek-2, and MicroScan. Nonsusceptibility was categorized as a tigecycline MIC of ≥4 µg/ml for both A. baumannii and Enterobacteriaceae. The study included 4,427 isolates: 2,065 ESBL-producing Enterobacteriaceae, 1,105 A. baumannii, 888 susceptible Enterobacteriaceae, and 369 CRE isolates. Tigecycline nonsusceptibility among A. baumannii isolates was significantly more common as determined by Etest compared to that determined by BMD (odds ratio [OR], 10.3; P<0.001), MicroScan (OR, 12.4; P<0.001), or Vitek-2 (OR, 9.4; P<0.001). These differences were not evident with the other pathogens. Tigecycline MICs varied greatly according to the in vitro testing methods among A. baumannii isolates. Etest should probably not be used by laboratories for tigecycline MIC testing of A. baumannii isolates, since MICs are significantly elevated with Etest compared to those determined by the three other methods.
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Bacterias Gramnegativas/efectos de los fármacos , Minociclina/análogos & derivados , Acinetobacter baumannii/efectos de los fármacos , Antibacterianos/farmacología , Carbapenémicos/farmacología , Enterobacteriaceae/efectos de los fármacos , Humanos , Michigan , Pruebas de Sensibilidad Microbiana/métodos , Minociclina/farmacología , Tigeciclina , beta-Lactamasas/metabolismoRESUMEN
The morphological dynamics of microbial cell proliferation on an antimicrobial surface at an early growth stage was studied with Escherichia coli on the surface of a gel supplied with AgNbO3 antimicrobial particles. We demonstrated an inhibitory surface concentration, analogous to minimum inhibitory concentration, beyond which the growth of colonies and formation of biofilm are inhibited. In contrast, at lower concentrations of particles, after a lag time the cells circumvent the antimicrobial activity of the particles and grow with a rate similar to the case in the absence of particles. The lag time depends on the surface concentration of the particles and amounts to 2 h at a concentration of ½ minimum inhibitory concentration. The applicability of these findings, in terms of estimating inhibitory surface concentration, was tested in the case of antimicrobial polymethyl methacrylate (PMMA) bone cement.
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Escherichia coli , Pruebas de Sensibilidad Microbiana , Escherichia coli/efectos de los fármacos , Escherichia coli/crecimiento & desarrollo , Biopelículas/efectos de los fármacos , Biopelículas/crecimiento & desarrollo , Polimetil Metacrilato/química , Antiinfecciosos/farmacología , Propiedades de Superficie , Antibacterianos/farmacología , Niobio/farmacología , Niobio/química , Cementos para Huesos/farmacologíaRESUMEN
We investigated the possibility of loading PMMA bone cement with antimicrobial nanostructured AgNbO3 particles to counter biofilm formation at the cement-tissue interface. We found that a formulation containing (1-4)% AgNbO3 showed high antibacterial activity against Gram-positive Staphylococcus aureus and Gram-negative Pseudomonas aeruginosa while not showing any toxicity against THP1 human cell lines. In addition, loading the particles did not impact the mechanical properties of the cement. The results thus obtained illustrate the potential of the approach to replace the current technique of mixing cement with conventional antibiotics, which is associated with shortcomings such as efficacy loss from antibiotic depletion.
Asunto(s)
Antibacterianos , Cementos para Huesos , Ensayo de Materiales , Pruebas de Sensibilidad Microbiana , Tamaño de la Partícula , Polimetil Metacrilato , Pseudomonas aeruginosa , Staphylococcus aureus , Cementos para Huesos/química , Cementos para Huesos/farmacología , Polimetil Metacrilato/química , Polimetil Metacrilato/farmacología , Antibacterianos/farmacología , Antibacterianos/química , Humanos , Staphylococcus aureus/efectos de los fármacos , Pseudomonas aeruginosa/efectos de los fármacos , Materiales Biocompatibles/química , Materiales Biocompatibles/farmacología , Biopelículas/efectos de los fármacos , Nanopartículas/químicaRESUMEN
Chimeric antigen receptor (CAR) T-cell therapy has emerged as a novel therapeutic option for hematologic malignancies. Human immunodeficiency virus (HIV) nucleic acid amplification tests (NAATs) amplifying 5' long terminal repeat and gag genes cross-react with lentiviral vector-based CAR T-cell products. Cross-reactivity between CAR T-cell products and HIV NAATs may lead to false-positive test results.
RESUMEN
We evaluated the ability of four commercial MIC testing systems (MicroScan, Vitek 2, Phoenix, and Etest) to detect vancomycin MIC values of ≤1 to ≥2 in 200 methicillin-resistant Staphylococcus aureus (MRSA) strains compared to the Clinical and Laboratory Standards Institute broth microdilution (BMD) reference methods. Compared to the BMD method, absolute agreement (0 ± dilution) was highest for the Phoenix system (66.2%) and the MicroScan turbidity method (61.8%), followed by the Vitek 2 system (54.3%). The Etest produced MIC values 1 to 2 dilutions higher than those produced by the BMD method (36.7% agreement). Of interest, the MicroScan system (prompt method) was more likely to overcall an MIC value of 1 mg/liter (74.1%), whereas the Phoenix (76%) and Vitek 2 (20%) systems had a tendency to undercall an MIC of 2 mg/liter. The ability to correctly identify vancomycin MIC values of 1 and 2 has clinical implications and requires further evaluation.