RESUMO
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.
Assuntos
Bactérias/classificação , Bactérias/genética , Reação em Cadeia da Polimerase Multiplex , Sepse/diagnóstico , Sepse/microbiologia , Leveduras/classificação , Leveduras/genética , Bactérias/efeitos dos fármacos , Farmacorresistência Bacteriana , Farmacorresistência Fúngica , Genes Bacterianos , Genes Fúngicos , Humanos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Leveduras/efeitos dos fármacosRESUMO
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.
Assuntos
Sangue/microbiologia , Candida/classificação , Candida/isolamento & purificação , Candidemia/diagnóstico , Candidemia/microbiologia , Hibridização in Situ Fluorescente/métodos , Técnicas Microbiológicas/métodos , Técnicas de Diagnóstico Molecular/métodos , Candida/genética , Humanos , Sensibilidade e EspecificidadeAssuntos
Complicações Infecciosas na Gravidez/diagnóstico , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Infecções Estreptocócicas/diagnóstico , Streptococcus agalactiae/crescimento & desenvolvimento , Adulto , Hemocultura , Centers for Disease Control and Prevention, U.S. , Meios de Cultura/química , Feminino , Humanos , Gravidez , Complicações Infecciosas na Gravidez/microbiologia , Sensibilidade e Especificidade , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/normas , Infecções Estreptocócicas/microbiologia , Streptococcus agalactiae/genética , Streptococcus agalactiae/isolamento & purificação , Estados Unidos , Vagina/microbiologiaRESUMO
When 13 of 13 nasal wash specimens from a single pediatrician's office tested positive for low quantities of Bordetella pertussis DNA, we suspected prelaboratory contamination. Investigation revealed that Pentacel and Adacel vaccines contain high copy numbers of B. pertussis DNA, which can be aerosolized, causing false-positive B. pertussis PCR results.
Assuntos
Aerossóis , Bordetella pertussis/isolamento & purificação , Reações Falso-Positivas , Vacina contra Coqueluche/administração & dosagem , Vacina contra Coqueluche/genética , Reação em Cadeia da Polimerase/métodos , Coqueluche/diagnóstico , Bordetella pertussis/genética , HumanosRESUMO
Staphylococcus pettenkoferi (S.pettenkoferi), originally described in Germany in 2002 by Trülzsch et al, is a coagulase negative staphylococcus whose clinical relevance is yet to be determined. With about 10 case reports in the literature from several parts of the world, there is no data on S. pettenkoferi infection from the United States. This is a retrospective cohort study of 80 patients ≥ 18 years of age who had at least 1 S. pettenkoferi-positive blood culture, identified by matrix-assisted laser desorption/ionization time-of-flight at a tertiary academic center in Detroit, Michigan. We describe the features of S. pettenkoferi-positive blood cultures in order to identify cases of true bacteremia. The mean age of the cohort was 66 ± 16 years and 1 out of 3 had immunosuppressing conditions. No case of true S.pettenkoferi bacteremia was identified. More studies are needed to determine its role as a pathogen in the United States.
Assuntos
Antibacterianos/farmacologia , Hemocultura , Infecções Estafilocócicas/diagnóstico , Infecções Estafilocócicas/microbiologia , Staphylococcus/efeitos dos fármacos , Idoso , Bacteriemia/epidemiologia , Bacteriemia/microbiologia , Estudos de Coortes , Farmacorresistência Bacteriana , Feminino , Humanos , Pacientes Internados , Masculino , Michigan/epidemiologia , Pessoa de Meia-Idade , Oxacilina/farmacologia , Estudos Retrospectivos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/epidemiologia , Centros de Atenção TerciáriaRESUMO
BACKGROUND: The protection against aerosol transmission provided by masks vs face shields or in combination when speaking indoors is not well understood. METHODS: To simulate a human source, an aerosol generating system was made using a bacterial suspension in a nebulizer attached to an oxygen cylinder. A fan connected to the nebulizer created aerosols. Transmitted aerosols were detected using blood agar plates at 0.1524 and 1.8288 meters from source, simulating exposed person. The study was performed under controlled conditions at room temperature in a biohazard hood with high-efficiency particulate air (HEPA) filter and UV light. RESULTS: When face shields were used alone, significant numbers of bacterial colonies grew on blood agar plates. When a mask used alone for both the subjects (source and exposed), the blood agar yielded minimal colony forming units at both distances. When face shields were used in combination with masks, no significant improvement was observed as compared to masks alone. DISCUSSION: Our results were similar to what have been observed in related studies. CONCLUSIONS: Surgical masks alone provided good protection, surpassing the protection provided by face shields alone. Both used together provided the best protection, although the combined protection was similar to surgical masks use alone.
Assuntos
Laboratórios , Máscaras , Aerossóis , HumanosRESUMO
BACKGROUND: The objective of this study was to evaluate the effect of maternal medications on nerve growth factor (NGF) and interleukin-6 (IL-6) levels in human breast milk (HBM). METHODS: A total of 30 samples of HBM were collected after consent from consecutively born term newborns. NGF and IL-6 concentrations were analyzed using ELISA assays from R&D Systems. The HBM samples were centrifuged, and the clear portion of the HBM after discarding the fat was analyzed and cytokine data were expressed as NGFC or IL-6C. Ten samples of HBM, which were not centrifuged, were also used in ELISA assays and cytokine data were expressed as NGFF or IL-6F. RESULTS: After exposure to NSAIDs (7636 ± 9610, mean ± SD, pg/mL), the NGFC levels in HBM were significantly higher as compared to those who were exposed to narcotics (522 ± 1000) (p = 0.008). NGFC and IL-6C levels positively correlated with each other in HBM (R = 0.194 p < 0.0001). NGFC levels (360 ± 237) were significantly lower than NGFF levels (888 ± 751) (p < 0.0001). IL-6F was higher than IL-6C levels without statistical significance. CONCLUSION: Further studies are warranted to elucidate effect of maternal medications on cytokine changes in HBM and effect of these cytokine changes on newborn gastrointestinal milieu.
Assuntos
Analgésicos/farmacologia , Antibacterianos/farmacologia , Interleucina-6/análise , Leite Humano/efeitos dos fármacos , Fator de Crescimento Neural/análise , Humanos , Leite Humano/químicaRESUMO
OBJECTIVE: To assess the effect of using 2 throat swabs vs 1 on rapid detection of group A streptococcus by the STREP A OIA MAX (hereafter, OIA MAX) test. METHODS: Children aged 5 to 18 years with acute pharyngitis were randomized to 1 of 2 study groups. In group 1, one throat swab was obtained, streaked first on sheep blood agar, and then used for OIA MAX testing. In group 2, two throat swabs were obtained simultaneously. One swab was streaked first on sheep blood agar and then joined with the other swab for OIA MAX testing. In both groups, the pledgets in the collection-transport tube were incubated in Todd-Hewitt broth. A positive group A streptococcus culture either by sheep blood agar or Todd-Hewitt broth was confirmed by a latex agglutination test. RESULTS: Three hundred sixty-three patients were enrolled, 177 in group 1 and 186 in group 2. Cultures were positive for group A streptococcus in 154 (42.4%) of 363 patients. The sensitivity and specificity of OIA MAX testing were 94.7% and 100.0%, respectively, in group 1, and 92.4% and 96.3%, respectively, in group 2. There was no statistical difference between the sensitivity, the specificity, and the predictive values of the OIA MAX test performed with 1 swab compared with those performed with 2 swabs (P>.10). There was no association between OIA MAX test sensitivity and the severity of pharyngitis as measured by the modified Centor criterion (history of fever, absence of cough, presence of pharyngeal or tonsillar exudates, and presence of cervical lymphadenopathy) scores. CONCLUSIONS: The OIA MAX test yielded comparable sensitivity and specificity in both study groups. The use of 2 throat swabs instead of 1 swab did not increase the sensitivity of the OIA MAX test. The performance of the OIA MAX test did not depend on the severity of pharyngitis.
Assuntos
Contagem de Colônia Microbiana/métodos , Faringite/microbiologia , Infecções Estreptocócicas/diagnóstico , Streptococcus pyogenes/isolamento & purificação , Adolescente , Criança , Pré-Escolar , Humanos , Faringite/diagnóstico , Faringite/fisiopatologia , Sensibilidade e Especificidade , Infecções Estreptocócicas/fisiopatologia , Streptococcus pyogenes/patogenicidadeRESUMO
Free fatty acid (FFA) concentrations in cerebrospinal fluid (CSF) are recognized as markers of brain damage in animal studies. There is, however, relatively little information regarding FFA concentrations in human CSF in normal and pathological conditions. The present study examined FFA concentrations in CSF from 15 patients with traumatic brain injury (TBI) and compared the data with values obtained from 73 contemporary controls. Concentrations of specific FFAs from TBI patients, obtained within 48 h of the insult were significantly greater than those in the control group (arachidonic, docosahexaenoic and myristic, P<0.001; oleic, palmitic, P<0.01; linoleic, P<0.05). Higher concentrations of total polyunsaturated fatty acids (P<0.001) and of arachidonic, myristic and palmitic acids measured individually in CSF (P<0.01) obtained 1 week after the insult were associated with a worse outcome at the time of hospital discharge using the Glasgow Outcome Scale. This preliminary investigation suggests that CSF FFA concentrations may be useful as a predictive marker of outcome following TBI.
Assuntos
Lesões Encefálicas/líquido cefalorraquidiano , Ácidos Graxos não Esterificados/líquido cefalorraquidiano , Ácido Araquidônico/líquido cefalorraquidiano , Biomarcadores/líquido cefalorraquidiano , Cromatografia Líquida de Alta Pressão , Ácidos Docosa-Hexaenoicos/líquido cefalorraquidiano , Escala de Resultado de Glasgow , Humanos , Ácido Linoleico/líquido cefalorraquidiano , Ácido Mirístico/líquido cefalorraquidiano , Ácido Oleico/líquido cefalorraquidiano , Ácido Palmítico/líquido cefalorraquidiano , PrognósticoRESUMO
OBJECT: The mechanisms leading to vasospasm following subarachnoid hemorrhage (SAH) remain unclear. Accumulation in cerebrospinal fluid (CSF) of free fatty acids (FFAs) may play a role in the development of vasospasm; however, in no previous study have concentrations of FFAs in CSF been examined after SAH. METHODS: We collected samples of CSF from 20 patients with SAH (18 cases of aneurysmal SAH and two cases of spontaneous cryptogenic SAH) and used a high-performance liquid chromatography assay to determine the FFA concentrations in these samples. We then compared these findings with FFA concentrations in the CSF of control patients. All FFA concentrations measured 24 hours after SAH were significantly greater than control concentrations (p < 0.01 for palmitic acid and < 0.001 for all other FFAs). All measured FFAs remained elevated for the first 48 hours after SAH (p < 0.05 for linoleic acid, p < 0.01 for palmitic acid, and p < 0.001 for the other FFAs). After 7 days, a second elevation in all FFAs was observed (p < 0.05 for linoleic acid, p < 0.01 for palmitic acid, and p < 0.001 for the other FFAs). Samples of CSF collected within 48 hours after SAH from patients in whom angiography and clinical examination confirmed the development of vasospasm after SAH were found to have significantly higher concentrations of arachidonic, linoleic, and palmitic acids than samples collected from patients in whom vasospasm did not develop (p < 0.05). CONCLUSIONS: Following SAH, all FFAs are initially elevated. A secondary elevation occurs between 8 and 10 days after SAH. This study provides preliminary evidence of FFA elevation following SAH and of a potential role for FFAs in SAH-induced vasospasm. A prospective study is warranted to determine if CSF concentrations of FFAs are predictive of vasospasm.
Assuntos
Ácidos Graxos não Esterificados/líquido cefalorraquidiano , Ácidos Graxos não Esterificados/fisiologia , Hemorragia Subaracnóidea/líquido cefalorraquidiano , Hemorragia Subaracnóidea/fisiopatologia , Vasoespasmo Intracraniano/líquido cefalorraquidiano , Vasoespasmo Intracraniano/fisiopatologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Ácido Araquidônico/líquido cefalorraquidiano , Ácidos Docosa-Hexaenoicos/líquido cefalorraquidiano , Feminino , Humanos , Ácido Linoleico/líquido cefalorraquidiano , Masculino , Pessoa de Meia-Idade , Ácido Mirístico/líquido cefalorraquidiano , Ácidos Oleicos/líquido cefalorraquidiano , Ácidos Palmíticos/líquido cefalorraquidiano , Hemorragia Subaracnóidea/complicações , Fatores de Tempo , Vasoespasmo Intracraniano/etiologiaRESUMO
Weissella confusa is found in fermented foods and has been suggested as a probiotic, but also causes sepsis and other serious infections in humans and animals. The incidence of human infections is underestimated partly due to confusion with viridans streptococci and partly due to difficulty making a definitive identification, even if the organism is recognized to belong to another genus, owing to the inability of commercial organism systems to identify it. We report our experiences identifying W. confusa isolated from two immune-compromised patients, both of whom developed sepsis with this organism. Two MicroScan gram positive combination panels, could not identify the organism because they did not have W. confusa in their data bases, but did not provide a false identification. Other laboratorians have reported failure to identify or false identifications of W. confusa with other commercial systems. W. confusa is in the data base of the RapID™ Str panel (Remel), which gave three incorrect, high probability results (≥95%). 16S rDNA sequencing identified the isolates as W. confusa. Maldi-Tof, performed by two of our reference laboratories, also correctly identified both isolates. Use of W. confusa as a probiotic should be approached with caution because its true incidence as an opportunisitic pathogen is unknown.
RESUMO
BACKGROUND: Previous antibiotic exposure is a risk factor for extended spectrum ß-lactamase (ESBL)-producing Klebsiella pneumoniae isolation, but the optimal definition of previous antibiotic exposure remains unclear. METHODS: This was a retrospective, case-control study comparing 88 patients with ESBL-producing K pneumoniae (cases) and 88 patients with non-ESBL-producing K pneumoniae (controls). Three previous antibiotic exposure definitions were analyzed, including durations of 30, 60, and 90 days prior to organism isolation. RESULTS: The mean cohort age was 63.6 ± 16.9 years, 43% were male, and 86% were black. In bivariate analysis, third-generation cephalosporins and cefepime were associated with ESBL-producing K pneumoniae isolation, and the odds ratios (OR) were significant regardless of previous antibiotic exposure definition. However, for fluoroquinolones and ampicillin/sulbactam, the ORs varied as a function of previous antibiotic exposure definition. In multivariate analysis, third-generation cephalosporin usage was a risk factor for ESBL-producing K pneumoniae isolation, whereas ampicillin/sulbactam usage was protective against these organisms, regardless of the time frame analyzed. Other independent predictors of ESBL-producing K pneumoniae included nursing home residence (OR, 9.30 [95% confidence interval: 3.69-23.43]) and hemodialysis (OR, 13.60 [95% confidence interval: 4.29-43.17]). CONCLUSION: Prior use of third-generation cephalosporins, nursing home residence, and hemodialysis were independent risk factors for isolation of an ESBL-producing K pneumoniae regardless of the time frame analyzed.
Assuntos
Infecções por Klebsiella/epidemiologia , Klebsiella pneumoniae/isolamento & purificação , beta-Lactamases/efeitos dos fármacos , Negro ou Afro-Americano , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/farmacologia , Estudos de Casos e Controles , Cefepima , Cefalosporinas/farmacologia , Estudos de Coortes , Infecção Hospitalar/tratamento farmacológico , Infecção Hospitalar/epidemiologia , Infecção Hospitalar/microbiologia , Feminino , Fluoroquinolonas/farmacologia , Humanos , Infecções por Klebsiella/tratamento farmacológico , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/enzimologia , Masculino , Michigan/epidemiologia , Pessoa de Meia-Idade , Análise Multivariada , Casas de Saúde , Razão de Chances , Diálise Renal , Estudos Retrospectivos , Fatores de Risco , Estados UnidosRESUMO
This paper reports a case of sepsis associated with a previously unknown Atopobium species and highlights the role of 16S ribosomal subunit sequencing in the rapid identification of slow-growing or atypical organisms in the clinical laboratory.
Assuntos
Actinobacteria/genética , Actinobacteria/isolamento & purificação , Infecções por Bactérias Gram-Positivas/microbiologia , Sepse/microbiologia , Actinobacteria/classificação , Adulto , Cromatografia Gasosa , Genes de RNAr , Infecções por Bactérias Gram-Positivas/diagnóstico , Humanos , Masculino , Testes de Sensibilidade Microbiana , Sepse/diagnóstico , Análise de Sequência de DNARESUMO
Staphylococcus aureus is a major cause of bacteremia and endocarditis in adults. Vancomycin is the standard therapy for methicillin-resistant Staphylococcus aureus (MRSA) bacteremia. Although clinical failure associated with the development of reduced susceptibility to vancomycin during the course of treatment for MRSA bacteremia has been reported infrequently, such an occurrence is very serious. We report a case of 43-year-old woman with of MRSA bacteremia, who relapsed after initial, apparently successful vancomycin treatment and developed left-sided endocarditis and vertebral osteomyelitis. Two weeks into her second admission, the vancomycin minimal inhibitory concentration rose from Assuntos
Antibacterianos/uso terapêutico
, Endocardite Bacteriana/tratamento farmacológico
, Staphylococcus aureus Resistente à Meticilina
, Osteomielite/tratamento farmacológico
, Infecções Estafilocócicas/tratamento farmacológico
, Resistência a Vancomicina
, Adulto
, Daptomicina/uso terapêutico
, Endocardite Bacteriana/diagnóstico
, Feminino
, Humanos
, Osteomielite/diagnóstico
, Infecções Estafilocócicas/diagnóstico
RESUMO
The Roche COBAS AMPLICOR human immunodeficiency virus type 1 (HIV-1) Monitor (version 1.5) standard and ultrasensitive viral load assays often gave discordant results, with viral loads from the standard assay exceeding those from the ultrasensitive assay by more than 0.5 log(10) for approximately 20% of specimens received. We began studies to determine the extent, magnitude, and reproducibility of the discordance between the assays and to discover and eliminate the cause of this discordance. Until then, we revised our standard operating procedure to include both standard and ultrasensitive testing on all specimens submitted for viral load determinations. Discordant results usually recurred on retesting. They were most prevalent for specimens with ultrasensitive viral loads of <1,000 and rare for specimens with viral loads of >10,000. Often, standard assay results exceeded those of the ultrasensitive assay by 50- to 100-fold. At higher viral loads, the difference between the standard and ultrasensitive assays persisted, but the percent difference was smaller and rarely caused discordance. The proportion of discordant results was significantly higher in specimens from pediatric patients than in specimens from adults. The ultrasensitive viral load determinations generally agreed with the results of the B-DNA (Bayer) viral load assays. If the plasma was transferred from the centrifuged plasma preparation tubes before freezing, standard and ultrasensitive results were concordant with each other and with values determined on plasma from lavender-topped EDTA tubes.