Rapid colorimetric polymyxin B microelution directly from positive blood bottles: because patients with serious infections should not have to wait for results of culture-based methodologies.

PURPOSE: To evaluate the performance of the rapid colorimetric polymyxin B microelution (RCPEm) in determining polymyxin B resistance directly from Enterobacterales-positive blood cultures. METHODS: A set volume of positive blood culture bottles (diluted 1:10) was inoculated into a glucose-broth-phenol red solution (NP solution), where a polymyxin B disk was previously eluted (final concentration of 3 µg/mL). Test was read each 1 h for up to 4 h. Color change from red/orange to yellow indicated resistant isolates. Results were compared to the reference method, broth microdilution (BMD), performed from colonies grown on solid media from the same blood culture bottle. RESULTS: One hundred fifty-two Enterobacterales-positive blood cultures were evaluated, 22.4% (34/152) of them resistant to polymyxin B (including 6.6% with borderline MICs). When performing directly from positive blood cultures (RCPEm-BC), specificity and sensitivity were 99.1% and 94.1%, respectively. Of note, 79.4% (27/34) of truly resistant isolates required 3 h of incubation, compared to the 18 ± 2 h incubation that microtiter plates of BMD demand before reading can be performed. CONCLUSIONS: RCPEm directly from blood cultures has great potential to be part of the routine of clinical microbiology laboratories to establish polymyxin B susceptibility, impacting outcome of patients with bloodstream infections caused by carbapenem-resistant Enterobacterales.

Culture-negative endocarditis with multifocal spread and flail mitral valve leaflet: a case report.

Introduction: Blood culture-negative infective endocarditis is the condition in which a causative organism cannot be identified after inoculation of at least three samples using standard blood-culture systems for 7 days. It has a low reported incidence of about 2.5-31%. Causes may be infectious or non-infectious; use of prior antibiotic therapy is usually the leading factor. Case presentation: The authors present a case of true culture-negative endocarditis involving the mitral valve, with multiple foci of spread including brain, spleen, liver, and Intervertebral disc, which remained persistent despite treatment with intravenous broad-spectrum antibiotics on an inpatient and outpatient basis but eventually improved after upgrading alternative broad-spectrum antibiotic for an extended duration. The patient had complications in the form of a flail mitral valve with persistent mitral regurgitation, requiring mitra-clip placement. Discussion: Positive blood culture is one of the major diagnostic criteria to establish infective endocarditis. Patients may have persistent negative cultures due to previous antibiotic use, the presence of fastidious organisms, or the use of inappropriate techniques or media. Involvement of a multidisciplinary team, use of multimodal investigations, and appropriate antibiotic stewardship are crucial. Extended duration of treatment and upgrading antibiotics can be helpful next steps in highly suspicious cases. With multifocal spread as in our case, it further becomes challenging to control and treat the infection as it is frequently connected with higher morbidity and mortality. Conclusion: Blood culture-negative endocarditis is an entity that can present with early complications. It is diagnostically and therapeutically challenging to treat such patients. Multimodal approaches for early diagnosis and appropriate treatment are crucial owing to its high morbidity and mortality.

Staphylococcus capitis Bloodstream Isolates: Investigation of Clonal Relationship, Resistance Profile, Virulence and Biofilm Formation.

Staphylococcus capitis has been recognized as a relevant opportunistic pathogen, particularly its persistence in neonatal ICUs around the world. Therefore, the aim of this study was to describe the epidemiological profile of clinical isolates of S. capitis and to characterize the factors involved in the persistence and pathogenesis of these strains isolated from blood cultures collected in a hospital in the interior of the state of São Paulo, Brazil. A total of 141 S. capitis strains were submitted to detection of the mecA gene and SCCmec typing by multiplex PCR. Genes involved in biofilm production and genes encoding enterotoxins and hemolysins were detected by conventional PCR. Biofilm formation was evaluated by the polystyrene plate adherence test and phenotypic resistance was investigated by the disk diffusion method. Finally, pulsed-field gel electrophoresis (PFGE) was used to analyze the clonal relationship between isolates. The mecA gene was detected in 99 (70.2%) isolates, with this percentage reaching 100% in the neonatal ICU. SCCmec type III was the most prevalent type, detected in 31 (31.3%) isolates and co-occurrence of SCCmec was also observed. In vitro biofilm formation was detected in 46 (32.6%) isolates but was not correlated with the presence of the ica operon genes. Furthermore, biofilm production in ICU isolates was favored by hyperosmotic conditions, which are common in ICUs because of the frequent parenteral nutrition. Analysis of the clonal relationship between the isolates investigated in the present study confirms a homogeneous profile of S. capitis and the persistence of clones that are prevalent in the neonatal ICU and disseminated across the hospital. This study highlights the adaptation of isolates to specific hospital environments and their high clonality.

Evaluation of the ceftazidime/avibactam and meropenem susceptibility by MALDI-TOF MS directly from positive blood cultures.

The purpose of this study was to evaluate the MBT-ASTRA to determine susceptibility to ceftazidime/avibactam (CZA) and meropenem (MEM) of Enterobacterales directly from positive blood cultures (BC). Bacterial suspension was incubated with antibiotic and analyzed by MALDI-TOF MS. The relative growth was calculated and cutoff values were determined to categorize isolates as "S," "I," and "R." Klebsiella spp. with CZA 20/8 mg/L and 1.5-h incubation presented 1 (5.9%) major discrepancy and 96.3% category agreement; other species required 2.5 h for 100% category agreement. For MEM, 4 mg/L and 1.5h were necessary, demonstrating 2 (6.67%) minor discrepancies and 93.3% categorical agreement.

Evaluation of an enzyme immunoassay technique on detecting urinary Histoplasma capsulatum antigen in the diagnosis of disseminated histoplasmosis in Argentina.

INTRODUCTION: Histoplasmosis is a systemic mycosis of universal distribution, highly endemic in the Americas. It is caused by a dimorphic fungus Histoplasma capsulatum var. capsulatum. It affects both immunocompetent and immunocompromised individuals where progressive and disseminated forms are observed. A very important risk factor is HIV infection/AIDS, with a mortality rate of 20-40% in Latin America. The diagnosis of this mycosis is made by conventional and molecular methods or by antigen and antibody detection. METHODS: In this retrospective, longitudinal and analytical study, carried out over a period of 2 years, the sensitivity (S) and specificity (E) of a commercial kit for the detection of Histoplasma antigen by EIA technique (HC-Ag) was evaluated in 50 patients with AIDSassociated histoplasmosis. In addition, its performance was compared with that of other diagnostic techniques routinely used in our laboratory. RESULTS: HC-Ag had a S of 94%, E 96%, positive likelihood coefficient (CVP): 20.68 and negative likelihood coefficient (CVN): 0.06. The delay time of the results was 4 days, similar to that of antibody detection and n-PCR and much less than that of blood cultures. The combination of methods improved S to 100%; with similar values in E. CONCLUSION: The HC-Ag method demonstrated its usefulness in the diagnosis of progressive disseminated histoplasmosis and the combination of methods is a good option to increase sensitivity and decrease the time to reach the diagnosis of certainty. This allows improving the strategy in the management of the disease and decreasing its case-fatality rate.

Introducción: La histoplasmosis es una micosis sistémica de distribución universal, altamente endémica en las Américas. Es causada por un hongo dimórfico: Histoplasma capsulatum var. capsulatum. Afecta tanto a inmunocompetentes como a inmunocomprometidos, se observan formas progresivas y diseminadas. Un factor de riesgo muy importante es la infección por HIV/sida, con una tasa de mortalidad del 20-40% en América Latina. El diagnóstico de esta micosis se realiza por métodos convencionales y moleculares o por detección de antígenos y anticuerpos. Métodos: En este estudio retrospectivo, longitudinal y analítico, realizado en un periodo de 2 años, se evaluó la sensibilidad (S) y especificidad (E) de un kit comercial para la detección de antígeno de Histoplasma por técnica de EIA (HC-Ag) en 50 pacientes con histoplasmosis asociada a sida. Además, se comparó su rendimiento con el de otras técnicas diagnósticas utilizadas habitualmente en nuestro laboratorio. Resultados: HC-Ag tuvo una S del 94%, E del 96%, coeficiente de verosimilitud positiva (CVP) de 20.68 y coeficiente de verosimilitud negativa (CVN) de 0.06. El tiempo de demora de los resultados fue de 4 días, similar al de la detección de anticuerpos y n-PCR y mucho menor que el de los hemocultivos. La combinación de métodos mejoró la S a 100%; con valores similares en E. Conclusión: El método HC-Ag demostró su utilidad en el diagnóstico de histoplasmosis diseminada progresiva y la combinación de métodos es una buena opción para aumentar la sensibilidad y disminuir el tiempo para llegar al diagnóstico de certeza. Esto permite mejorar la estrategia en el manejo de la enfermedad y reducir su tasa de letalidad.

Evaluation of an enzyme immunoassay technique on detecting urinary Histoplasma capsulatum antigen in the diagnosis of disseminated histoplasmosis in Argentina / Evaluación de una técnica de inmunoensayo enzimático para la detección del antígeno urinario de Histoplasma capsulatum en el diagnóstico de histoplasmosis diseminada en Argentina

Abstract Introduction : Histoplasmosis is a systemic mycosis of universal distribution, highly endemic in the Americas. It is caused by a dimorphic fungus Histoplasma capsulatum var. capsulatum. It affects both immunocompetent and immunocompromised individuals where progressive and disseminated forms are observed. A very important risk factor is HIV infection/AIDS, with a mortality rate of 20-40% in Latin America. The diagnosis of this mycosis is made by conventional and molecular methods or by antigen and antibody detection. Methods : In this retrospective, longitudinal and ana lytical study, carried out over a period of 2 years, the sensitivity (S) and specificity (E) of a commercial kit for the detection of Histoplasma antigen by EIA technique (HC-Ag) was evaluated in 50 patients with AIDS-associated histoplasmosis. In addition, its performance was compared with that of other diagnostic techniques routinely used in our laboratory. Results : HC-Ag had a S of 94%, E 96%, positive likeli hood coefficient (CVP): 20.68 and negative likelihood coefficient (CVN): 0.06. The delay time of the results was 4 days, similar to that of antibody detection and n-PCR and much less than that of blood cultures. The combination of methods improved S to 100%; with simi lar values in E. Conclusion : The HC-Ag method demonstrated its usefulness in the diagnosis of progressive disseminated histoplasmosis and the combination of methods is a good option to increase sensitivity and decrease the time to reach the diagnosis of certainty. This allows improv ing the strategy in the management of the disease and decreasing its case-fatality rate.

Resumen Introducción : La histoplasmosis es una micosis sis témica de distribución universal, altamente endémica en las Américas. Es causada por un hongo dimórfico: Histoplasma capsulatum var. capsulatum. Afecta tanto a inmunocompetentes como a inmunocomprometidos, se observan formas progresivas y diseminadas. Un factor de riesgo muy importante es la infección por HIV/sida, con una tasa de mortalidad del 20-40% en América Latina. El diagnóstico de esta micosis se realiza por métodos convencionales y moleculares o por detección de antígenos y anticuerpos. Métodos : En este estudio retrospectivo, longitudinal y analítico, realizado en un periodo de 2 años, se evaluó la sensibilidad (S) y especificidad (E) de un kit comercial para la detección de antígeno de Histoplasma por técnica de EIA (HC-Ag) en 50 pacientes con histoplasmosis aso ciada a sida. Además, se comparó su rendimiento con el de otras técnicas diagnósticas utilizadas habitualmente en nuestro laboratorio. Resultados : HC-Ag tuvo una S del 94%, E del 96%, coeficiente de verosimilitud positiva (CVP) de 20.68 y coeficiente de verosimilitud negativa (CVN) de 0.06. El tiempo de demora de los resultados fue de 4 días, simi lar al de la detección de anticuerpos y n-PCR y mucho menor que el de los hemocultivos. La combinación de métodos mejoró la S a 100%; con valores similares en E. Conclusión : El método HC-Ag demostró su utilidad en el diagnóstico de histoplasmosis diseminada progresiva y la combinación de métodos es una buena opción para aumentar la sensibilidad y disminuir el tiempo para llegar al diagnóstico de certeza. Esto permite mejorar la estrategia en el manejo de la enfermedad y reducir su tasa de letalidad.

Utilidad diagnóstica de los tiempos de positividad de hemocultivos para distinguir verdaderas bacteriemias de contaminantes en base a un sistema automatizado / Diagnostic performance of the time to positivity of blood cultures to distinguish true bacteremia from contaminants based on an automated system

RESUMEN Objetivo. Determinar la utilidad diagnóstica de los tiempos de positividad de hemocultivos para distinguir verdaderas bacteriemias de contaminantes en el sistema automatizado «BACT/ALERT®¼. Materiales y métodos. Se realizó un estudio transversal de tipo pruebas diagnósticas, a partir de una base de datos de muestras de hemocultivos procesadas entre enero del 2016 y agosto del 2021. Se incluyeron todas las muestras de hemocultivos de pacientes con sospecha de bacteriemia, las muestras de hemocultivos fueron ingresadas al sistema «BACT/ALERT®¼ para diferenciar verdaderas bacteriemias de contaminantes. Resultados. Se analizó un total de 33 951 frascos de hemocultivos y se obtuvieron 3875 frascos positivos. El 75,2% (n=2913) del total de hemocultivos positivos fueron verdaderas bacteriemias y 24,8% (n=962) fueron contaminantes. La mediana de tiempo de positividad en los hemocultivos con verdaderas bacteriemias fue significativamente menor (16,3 horas; RIC: 11,2 - 24,9) que la mediana de tiempo de positividad de hemocultivos con contaminantes (22,5 horas; RIC: 18,4 - 31,8; p<0,001). El tiempo de positividad demostró capacidad discriminante para diferenciar verdaderas bacteriemias de contaminantes, con un AUC-ROC de 0,73 (IC95%: 0,71 - 0,75), con 85% y 63% de sensibilidad y especificidad respectivamente para el diagnóstico de contaminantes cuando el tiempo de positividad supera las 16,5 horas. La administración de antibióticos previos a la toma retrasó el tiempo de positividad, en cambio, haber presentado fiebre antes de la toma de muestra acortó el tiempo de positividad. Conclusiones. Nuestros resultados muestran un buen desempeño de los tiempos de positividad de hemocultivos para diferenciar verdaderas bacteriemias de contaminantes utilizando el sistema «BACT/ALERT®¼ cuando el tiempo de positividad fue superior a 16,5 horas.

ABSTRACT Objective. To determine the diagnostic performance of blood culture positivity times for distinguishing true bacteremia from contaminants in the automated "BACT/ALERT®" system. Materials and methods. A cross-sectional, diagnostic test-type study was conducted from a database of blood culture samples processed between January 2016 and August 2021. All blood culture samples from patients with suspected bacteremia were included; blood culture samples were entered into the "BACT/ALERT®" system to differentiate true bacteremia from contaminants. Results. We obtained 33,951 blood cultures samples, of which 3875 were positive. Of the total number of positive blood cultures, 75.2% (n=2913) were true bacteremia and 24.8% (n=962) were contaminants. The median time to positivity in blood cultures with true bacteremia was significantly shorter (16.3 hours; IQR: 11.2 - 24.9) than the median time to positivity of blood cultures with contaminants (22.5 hours; IQR: 18.4 - 31.8; p<0.001). The positivity time showed the capacity to differentiate true bacteremia from contaminants, with an AUC-ROC of 0.73 (95%CI: 0.71 - 0.75), with 85% and 63% sensitivity and specificity respectively for the diagnosis of contaminants when the positivity time exceeds 16.5 hours. The use of antibiotics prior to sampling delayed the time to positivity, while having fever before sampling shortened the time to positivity. Conclusions. Our results show good diagnostic performance of blood culture positivity times to differentiate true bacteremia from contaminants using the "BACT/ALERT®" system when the positivity time was longer than 16.5 hours.

Diagnostic Stewardship: A Systematic Review and Meta-analysis of Blood Collection Diversion Devices Used to Reduce Blood Culture Contamination and Improve the Accuracy of Diagnosis in Clinical Settings.

Background: Blood culture contamination may lead to misdiagnosis, overutilization of antibiotics, and prolonged length of stay. Blood specimen diversion devices can reduce contamination rates during blood culture collection procedures. We performed a systematic literature review and meta-analysis evaluating the influence of blood specimen diversion devices in blood culture contamination rates. Methods: We searched Medline, Cumulative Index to Nursing and Allied Health Literature, Embase, Cochrane, Scopus, and Web of Science, from database inception to 1 March 2023, for studies evaluating the impact of a diversion device on blood culture contamination. Blood culture contamination was a positive blood culture with microorganisms not representative of true bacteremia, but rather introduced during collection or processing the blood sample. Random-effects models were used to obtain pooled mean differences, and heterogeneity was assessed using the I2 test. Results: Of 1768 screened studies, 12 met inclusion criteria for this systematic literature review. Of them, 9 studies were included in the meta-analysis. Studies were substantially heterogeneous, but stratified analyses considering only high-quality studies revealed that venipuncture using a diversion device was associated with a significant reduction in blood culture contamination in comparison to the standard procedure of collection (pooled odds ratio [OR], 0.26 [95% confidence interval {CI}, .13-.54]; I2 = 19%). Furthermore, the stratified analysis showed that the adoption of a diversion device did not reduce the detection of true infection (pooled OR, 0.85 [95% CI, .65-1.11]; I2 = 0%). Conclusions: Blood culture diversion devices was associated with decreased contamination rates and could improve quality of care, reduce costs, and avoid unnecessary antibiotic use.

MALDI-TOF MS-Based KPC Direct Detection from Patients' Positive Blood Culture Bottles, Short-Term Cultures, and Colonies at the Hospital.

Carbapenemase resistance in Enterobacterales is a global public health problem and rapid and effective methods for detecting these resistance mechanisms are needed urgently. Our aim was to evaluate the performance of a MALDI-TOF MS-based "Klebsiella pneumoniae carbapenemase" (KPC) detection protocol from patients' positive blood cultures, short-term cultures, and colonies in healthcare settings. Bacterial identification and KPC detection were achieved after protein extraction with organic solvents and target spot loading with suitable organic matrices. The confirmation of KPC production was performed using susceptibility tests and blaKPC amplification using PCR and sequencing. The KPC direct detection (KPC peak at approximately 28.681 Da) from patients' positive blood cultures, short-term cultures, and colonies, once bacterial identification was achieved, showed an overall sensibility and specificity of 100% (CI95: [95%, 100%] and CI95: [99%, 100%], respectively). The concordance between hospital routine bacterial identification protocol and identification using this new methodology from the same extract used for KPC detection was ≥92%. This study represents the pioneering effort to directly detect KPC using MALDI-TOF MS technology, conducted on patient-derived samples obtained from hospitals for validation purposes, in a multi-resistance global context that requires concrete actions to preserve the available therapeutic options and reduce the spread of antibiotic resistance markers.

Bloodstream infections and antibiotic resistance at a regional hospital, Colombia, 2019-2021.

Objectives: To assess antibiotic susceptibility of World Health Organization (WHO) priority bacteria (Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae, Salmonella spp., Staphylococcus aureus, and Streptococcus pneumoniae) in blood cultures at the Orinoquía regional hospital in Colombia. Methods: This was cross-sectional study using routine laboratory data for the period 2019-2021. Data on blood samples from patients suspected of a bloodstream infection were examined. We determined: the total number of blood cultures done and the proportion with culture yield; the characteristics of patients with priority bacteria; and the type of bacteria isolated and antibiotic resistance patterns. Results: Of 25 469 blood cultures done, 1628 (6%) yielded bacteria; 774 (48%) of these bacteria were WHO priority pathogens. Most of the priority bacteria isolated (558; 72%) were gram-negative and 216 (28%) were gram-positive organisms. Most patients with priority bacteria (666; 86%) were hospitalized in wards other than the intensive care unit, 427 (55%) were male, and 321 (42%) were ≥ 60 years of age. Of the 216 gram-positive bacteria isolated, 205 (95%) were Staphylococcus aureus. Of the 558 gram-negative priority bacteria isolated, the three most common were Escherichia coli (34%), Klebsiella pneumoniae (28%), and Acinetobacter baumannii (20%). The highest resistance of Staphylococcus aureus was to oxacillin (41%). For gram-negative bacteria, resistance to antibiotics ranged from 4% (amikacin) to 72% (ampicillin). Conclusions: Bacterial yield from blood cultures was low and could be improved. WHO priority bacteria were found in all hospital wards. This calls for rigorous infection prevention and control standards and continued surveillance of antibiotic resistance.

Direct Detection of KPC Peak from Positive Blood Cultures Using MALDI-TOF MS: Are We There Yet?

Detecting carbapenemase-associated carbapenem resistance is a subject of major clinical and epidemiological concern as it influences therapeutic choice. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) has been proposed as a means to assess bacterial resistance mechanisms. We aimed to detect the KPC enzyme directly from positive blood cultures using MALDI-TOF MS. To do so, 102 clinical Enterobacteria were evaluated, including 59 blaKPC positives. Proteins were extracted using formic acid, isopropyl alcohol, and water (17:33:50) and spotted onto a steel target plate using the double-layer sinapinic acid technique. Two parameters were considered: (i) the visual detection of a clear peak with the expected KPC m/z and (ii) the evaluation of the relative intensity of the ions in the peak. A peak was observed in 56/59 blaKPC-positive isolates (94.9% sensitivity), with no false-positive results (100% specificity). When considering intensity, with a cut-off ≥120 (a.u.), sensitivity was 94.9% and specificity was 95.3%. We proposed a "buffer" zone, with intermediate values of intensity (115 to 125) reaching 100% sensitivity and specificity. The detection of KPC peaks directly from positive blood cultures using MALDI-TOF MS is feasible and rapid, which may improve appropriate patient therapy and antimicrobial stewardship.

Prevalência de leveduras do gênero Candida isoladas de hemocultura de pacientes hospitalizados / Prevalence of yeasts of the genus Candida isolated from blood cultures of hospitalized patients

Introdução: A infecção da corrente sanguínea (ICS) por leveduras, tem como principal gênero a Candida. As principais espécies que causam a candidemia no Brasil são Candida albicans, Candida parapsilosis e Candida tropicalis, sendo a C. albicans a mais prevalente. Todavia, nas últimas décadas tem aumentado a prevalência de espécies de Candidanão albicans (CNA) e principalmente a emergência de Candida auris, que possuem mecanismos de resistência aos antifúngicos mais usados, caracterizando um cenário de preocupação mundial. Objetivo: Avaliar a prevalência de candidemia e das principais espécies de Candida spp. isoladas de amostras de hemocultura e sua distribuição por setores de internação de um hospital de ensino. Material e Métodos: Trata-se de um estudo observacional e retrospectivo, em que foram analisadas, através de bancos de dados, hemoculturas positivas para Candida spp. de pacientes internados em um hospital de ensino da cidade de Juiz de Fora, Minas Gerais, no período de janeiro de 2021 a dezembro de 2022. Resultados: Foram analisadas 3.262 hemoculturas, sendo 1.059 (32,46%) positivas. Destas, 1.008 (95,18%) tiveram crescimento bacteriano e 51 (4,82%) tiveram crescimento de Candida spp. divididos em, 20 (39,22%) C. albicans e 31 (60,78%) CNA. Das CNA isolados, 14 foram C. tropicalis (45,16%), 10 C. parapsilosis(32,26%), 3 C. glabrata (9,68%), 2 Candida kefyr (6,45%) e 2 Candida lusitaniae (6,45%). Dos 51 isolados de Candida spp., 25 (49,02%) foram no centro de tratamento intensivo, 11 (21,57%) no bloco cirúrgico e 15 (29,41%) foram nas enfermarias. Conclusão: Candida albicans é a principal espécie relacionada a candidemia em pacientes hospitalizados, porém espécies do grupo CNA têm apresentado elevada prevalência em isolados de hemocultura, principalmente em pacientes de centro de tratamento intensivo.

Introduction: Bloodstream infection (BSI) by yeasts has Candida as its main genus. The main species that cause candidemia in Brazil are Candida albicans, Candida parapsilosis and Candida tropicalis, and C. albicans referred as the most prevalent. However, in recent decades, the prevalence of non-albicans Candida species (NAC) has increased and especially the emergence of Candida auris, which have mechanisms of resistance to the most used antifungals, characterizing a scenario of global concern. Objective: To evaluate the prevalence of candidemia and the main species of Candida spp. isolated from blood culture samples and their distribution by hospitalization sectors of a teaching hospital. Material and Methods: This is an observational and retrospective study, of positive blood cultures for Candida spp. of patients admitted to a teaching hospital in the city of Juiz de Fora, Minas Gerais, from January 2021 to December 2022. Results: Among 3262 blood cultures analyzed, 1059 (32.46%) of which were positive. Of these, 1008 (95.18%) had bacterial growth and 51 (4.82%) had Candida spp. divided into, 20 (39.22%) C. albicans and 31 (60.78%) NAC. Of the NAC isolated, 14 were C. tropicalis (45.16%), 10 C. parapsilosis (32.26%), 3 C. glabrata (9.68%), 2 Candida kefyr (6.45%) and 2 Candida lusitaniae (6.45%). Of the 51 Candida spp. isolates, 25 (49.02%) were in the intensive care unit, 11 (21.57%) in the operating room and 15 (29.41%) were in the wards. Conclusion: Candida albicans is the main species related to candidemia in hospitalized patients, but species from the NAC group have shown high prevalence in blood culture isolates, especially in the intensive care unit patients.

Bloodstream infections and antibiotic resistance at a regional hospital, Colombia, 2019-2021 / Infecciones del torrente sanguíneo y resistencia a los antibióticos en un hospital regional en Colombia, 2019-2021 / Infecções de corrente sanguínea e resistência a antibióticos em um hospital regional, Colômbia, 2019-2021

ABSTRACT Objectives. To assess antibiotic susceptibility of World Health Organization (WHO) priority bacteria (Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae, Salmonella spp., Staphylococcus aureus, and Streptococcus pneumoniae) in blood cultures at the Orinoquía regional hospital in Colombia. Methods. This was cross-sectional study using routine laboratory data for the period 2019-2021. Data on blood samples from patients suspected of a bloodstream infection were examined. We determined: the total number of blood cultures done and the proportion with culture yield; the characteristics of patients with priority bacteria; and the type of bacteria isolated and antibiotic resistance patterns. Results. Of 25 469 blood cultures done, 1628 (6%) yielded bacteria; 774 (48%) of these bacteria were WHO priority pathogens. Most of the priority bacteria isolated (558; 72%) were gram-negative and 216 (28%) were gram-positive organisms. Most patients with priority bacteria (666; 86%) were hospitalized in wards other than the intensive care unit, 427 (55%) were male, and 321 (42%) were ≥ 60 years of age. Of the 216 gram-positive bacteria isolated, 205 (95%) were Staphylococcus aureus. Of the 558 gram-negative priority bacteria isolated, the three most common were Escherichia coli (34%), Klebsiella pneumoniae (28%), and Acinetobacter baumannii (20%). The highest resistance of Staphylococcus aureus was to oxacillin (41%). For gram-negative bacteria, resistance to antibiotics ranged from 4% (amikacin) to 72% (ampicillin). Conclusions. Bacterial yield from blood cultures was low and could be improved. WHO priority bacteria were found in all hospital wards. This calls for rigorous infection prevention and control standards and continued surveillance of antibiotic resistance.

RESUMEN Objetivos. Evaluar la sensibilidad a los antibióticos de las bacterias incluidas en la lista prioritaria de la Organización Mundial de la Salud (OMS) (Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae, Salmonella spp., Staphylococcus aureus y Streptococcus pneumoniae) en hemocultivos en el Hospital Regional de la Orinoquía en Colombia. Métodos. Se trata de un estudio transversal que empleó datos rutinarios de laboratorio del período comprendido entre los años 2019 y 2021. Se examinaron datos de muestras de sangre de pacientes con presunción clínica de infección del torrente sanguíneo. Se determinó el número total de hemocultivos realizados y la proporción cultivos con resultados, las características de los pacientes con bacterias prioritarias, así como el tipo de bacterias aisladas y los patrones de resistencia a los antibióticos. Resultados. De 25 469 hemocultivos realizados, se aislaron bacterias en 1628 (6%); 774 (48%) con agentes patógenos prioritarios de la OMS. La mayoría de las cepas bacterianas prioritarias aisladas (558; 72%) eran gramnegativas y 216 (28%), organismos grampositivos. La mayoría de los pacientes con bacterias prioritarias (666; 86%) fueron hospitalizados en salas distintas de la unidad de cuidados intensivos, 427 (55%) eran varones y 321 (42%) tenían 60 años o más. De las 216 bacterias grampositivas aisladas, 205 (95%) eran Staphylococcus aureus. De las 558 bacterias prioritarias gramnegativas aisladas, las tres más comunes fueron Escherichia coli (34%), Klebsiella pneumoniae (28%) y Acinetobacter baumannii (20%). La mayor resistencia de Staphylococcus aureus fue a la oxacilina (41%). Entre las bacterias gramnegativas, la resistencia a los antibióticos varió del 4% (amikacina) al 72% (ampicilina). Conclusiones. El aislamiento de bacterias en los hemocultivos fue bajo y podría mejorarse. Se encontraron bacterias de la lista prioritaria de la OMS en todas las salas del hospital, por lo que es necesario aplicar rigurosas normas de prevención y control de infecciones y realizar una vigilancia continua de la resistencia a los antibióticos.

RESUMO Objetivos. Avaliar a suscetibilidade a antibióticos das bactérias consideradas prioritárias pela Organização Mundial da Saúde (OMS) (Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae, Salmonella spp., Staphylococcus aureus e Streptococcus pneumoniae) em hemoculturas coletadas no hospital regional de Orinoquía na Colômbia. Métodos. Estudo transversal utilizando dados laboratoriais de rotina do período 2019-2021. Foram examinados os dados de amostras de sangue de pacientes com suspeita de infecção de corrente sanguínea. Determinamos o número total de hemoculturas realizadas e a proporção de culturas com rendimento, as características dos pacientes com bactérias prioritárias, e o tipo de bactéria isolada e padrões de resistência a antibióticos. Resultados. Das 25.469 hemoculturas realizadas, 1.628 (6%) foram positivas para bactérias, sendo que 774 (48%) dessas bactérias eram da lista de agentes patogênicos prioritários da OMS. A maioria das bactérias prioritárias isoladas (558; 72%) eram gram-negativas e 216 (28%) eram gram-positivas. A maioria dos pacientes com bactérias prioritárias (666; 86%) estava internada em enfermaria, e não em unidade de terapia intensiva. 427 (55%) eram homens e 321 (42%) tinham ≥ 60 anos de idade. Das 216 bactérias gram-positivas isoladas, 205 (95%) eram Staphylococcus aureus. Das 558 bactérias gram-negativas prioritárias isoladas, as três mais frequentes foram Escherichia coli (34%), Klebsiella pneumoniae (28%) e Acinetobacter baumannii (20%). O Staphylococcus aureus apresentou maior resistência à oxacilina (41%). Entre as bactérias gram-negativas, a resistência aos antibióticos variou entre 4% (amicacina) e 72% (ampicilina). Conclusões. O rendimento bacteriano das hemoculturas foi baixo e pode ser melhorado. As bactérias consideradas prioritárias pela OMS foram encontradas em todas as enfermarias do hospital. Os achados exigem normas rigorosas de prevenção e controle de infecção, e vigilância contínua da resistência bacteriana a antibióticos.

The role of the serum tube agglutination test in the monitoring of human brucellosis: evaluation of post-treatment SAT titers

SUMMARY OBJECTIVE: Positive results of the serum tube agglutination test that persist after treatment may be interpreted by clinicians as treatment failures. Therefore, our study examined the value of serum tube agglutination test in demonstrating treatment success. METHODS: In this retrospective study conducted at a single center, the pre- and post-treatment serum tube agglutination test titers of patients diagnosed with brucellosis were compared. RESULTS: The end-of-treatment serum tube agglutination test titer was negative in 24 (18%) of 139 patients diagnosed with brucellosis. The most common complaints of the patients were fever (78.4%), chills (88.5%), sweating (84.9%), anorexia (79.1%), and arthralgia (63.3%). The rate of positive blood culture before the treatment was 68.3%. The absence of fever (p=0.005) and arthralgia (p=0.024) and the pretreatment serum tube agglutination test titer of <1/160 (p=0.014) were significant markers of serological cure. CONCLUSION: Although serum tube agglutination test is an effective and very successful test in the diagnosis of brucellosis, our study shows that serum tube agglutination test is not useful in demonstrating the treatment success of human brucellosis in the early post-treatment period.

Sensitivity profile of blood culture isolates in a clinical analysis laboratory, Fortaleza, CE / Perfil de sensibilidade de isolados de hemocultura em um laboratório de análises clínicas, Fortaleza, CE / Perfil de sensibilidad de hemocultivos aislados en un laboratorio de análisis clínicos, Fortaleza, CE

Background and objectives: bacteremia is defined from the presence of bacteria in the bloodstream. Its clinical importance is associated with the high morbidity and mortality rate in the world. In severe cases, it can culminate in sepsis, with a constant increase in cases in Brazil. Therefore, this study aims to assess the main bacterial isolates in blood cultures and a possible change in their sensitivity profiles in a clinical analysis laboratory in Fortaleza, Ceará. Methods: an epidemiological, descriptive, retrospective study was carried out, with a quantitative approach of positive blood cultures, seeking to assess the main isolated microorganisms and their sensitivity profiles. The data used were obtained from the laboratory system through the EpiCenter→ software, from January 2019 to December 2020. Statistical analysis was performed using the Graphpad 7.0 software. Results: 840 microorganisms were identified from blood cultures, and the main ones were E. coli, K. pneumoniae, P. aeruginosa, S. epidermidis, S. aureus and S. haemolyticus. Some isolates show a change in the sensitivity profile, such as K. pneumoniae and P. aeruginosa, showing an increase in sensitivity to carbapenems and cephalosporins, while S. epidermidis showed a decrease in sensitivity to minocycline in the comparison between years 2019 and 2020.Conclusion: clinical isolates from blood cultures showed a change in the sensitivity profile between 2019 and 2020, taking into account that, for K. pneumoniae, P. aeruginosa, this change resulted in an increase in sensitivity, with an increase in resistance in S. epidermidis isolates.(AU)

Justificativa e objetivos: bacteremia é definida a partir da presença de bactérias na corrente sanguínea. Sua importância clínica está associada à alta taxa de morbidade e mortalidade no mundo. Nos casos graves, pode culminar em sepse, com constante aumento dos casos no Brasil. Portanto, o presente estudo tem como objetivo avaliar os principais isolados bacterianos em hemoculturas e uma possível alteração nos seus perfis de sensibilidade em um laboratório de análises clínicas de Fortaleza, Ceará. Métodos: foi realizado um estudo epidemiológico, descritivo, retrospectivo, com abordagem quantitativa de hemoculturas positivas, buscando avaliar os principais microrganismos isolados e seus perfis de sensibilidades. Os dados utilizados foram obtidos a partir do sistema laboratorial através do software EpiCenter→, referente ao período de janeiro de 2019 a dezembro de 2020. A análise estatística foi realizada pelo software Graphpad 7.0. Resultados: foram identificados 840 microrganismos a partir das hemoculturas, sendo os principais E. coli, K. pneumoniae, P. aeruginosa, S. epidermidis, S. aureus e S. haemolyticus. Alguns isolados apresentam uma alteração no perfil de sensibilidade, como K. pneumoniae e P. aeruginosa, apresentando um aumento na sensibilidade frente aos carbapenêmicos e as cefalosporinas, enquanto o S. epidermidis apresentou uma diminuição na sensibilidade frente à minociclina na comparação entre os anos de 2019 e 2020. Conclusão: os isolados clínicos de hemocultura apresentaram uma alteração no perfil de sensibilidade entre 2019 e 2020, levando em consideração que, para K. pneumoniae e P. aeruginosa, essa alteração resultou no aumento na sensibilidade, com aumento na resistência nos isolados de S. epidermidis.(AU)

Justificación y objetivos: la bacteriemia se define por la presencia de bacterias en el torrente sanguíneo. Su importancia clínica está asociada con la alta tasa de morbimortalidad en el mundo. En casos severos, puede culminar en sepsis, con un aumento constante de casos en Brasil. Por tanto, este estudio tiene como objetivo evaluar los principales aislados bacterianos en hemocultivos y un posible cambio en sus perfiles de sensibilidad en un laboratorio de análisis clínicos en Fortaleza, Ceará. Métodos: se realizó un estudio epidemiológico, descriptivo, retrospectivo, con abordaje cuantitativo de hemocultivos positivos, buscando evaluar los principales microorganismos aislados y sus perfiles de sensibilidad. Los datos utilizados se obtuvieron del sistema de laboratorio a través del software EpiCenter→, para el período de enero de 2019 a diciembre de 2020. El análisis estadístico se realizó mediante el software Graphpad 7.0. Resultados: se identificaron 840 microorganismos a partir de hemocultivos, siendo los principales E. coli, K. pneumoniae, P. aeruginosa, S. epidermidis, S. aureus y S. haemolyticus. Algunos aislados muestran un cambio en el perfil de sensibilidad, como K.pneumoniae y P. aeruginosa, mostrando un aumento en la sensibilidad a los carbapenémicos y cefalosporinas, mientras que S. epidermidis mostró una disminución en la sensibilidad a la minociclina, en la comparación entre los años de 2019 y 2020. Conclusiones: los aislados clínicos de hemocultivos mostraron un cambio en el perfil de sensibilidad entre 2019 y 2020, teniendo en cuenta que para K. pneumoniae, P. aeruginosa, este cambio resultó en un aumento de la sensibilidad, con un aumento de la resistencia en los aislados de S. epidermidis

Update on Pediatric Sepsis in Mexico.

The main objective of this work was to determine and update the causal agents' antibiotic sensitivity and resistance patterns on pediatric sepsis in a population of northeast Mexico. It is a cross-sectional study showing the results of blood cultures of pediatric patients with a presumptive diagnosis of sepsis were reviewed according to the SOFA criteria during 2020 in a public hospital in Mexico. A total of 207 blood cultures were performed and analyzed. The main isolated microorganisms were Staphylococcus, followed by Klebsiella and Escherichia. Several microorganisms showed 100% of sensitivity to different antibiotics or antifungals, some of them include Vancomycin, Voriconazole, Meropenem, Ciprofloxacin, and Cefotaxime. Bacteria of genre Staphylococcus showed its highest sensitivity rate to Tigecycline with 63.3%. Too Staphylococcus showed the highest resistance rate to Oxacillin with 50%. Although the patterns of sepsis-causing germs are similar to those previously reported, the development of new drugs with greater efficacy is the main contribution.

Nivel de conocimiento sobre la extracción de hemocultivos en enfermeras de la Unidad de Cuidados Intensivos / Level of Knowledge about Blood Culture Extractions in Intensive Care Unit Nurses

Introducción: El hemocultivo es una prueba sencilla, pero existe el riesgo de contaminación por un inadecuado procedimiento, en muchas ocasiones puede estar relacionado con la mala praxis del personal de enfermería. Objetivo: Valorar el nivel de conocimientos sobre la técnica de extracción de hemocultivo en enfermeras de una Unidad de Cuidados Intensivos. Métodos: Se realizó estudio descriptivo, transversal, en la Unidad de Cuidados Intensivos del Centro Nacional de Cirugía de Mínimo Acceso, La Habana, en enero 2021. La población estuvo conformada por 12 licenciadas en enfermería, se aplicó un cuestionario de conocimiento con la escala de puntuación: 0-30 puntos (no conocimiento); 31-60 puntos (poco conocimiento); 61-90 puntos (adecuado conocimiento), 91-100 puntos (excelente conocimiento). Se calcularon las frecuencias absolutas, porcentaje, prueba T para una muestra y chi cuadrado. Se utilizó el programa IBM SPSS versión 20 para Windows. Resultados: De la muestra estudiada, 41,70 por ciento consideró que el hemocultivo se realiza a pacientes febriles y el uso de guantes estériles como único medio de protección; 33,30 por ciento hizo referencia al alcohol como antiséptico cutáneo de elección; 58,30 % planteó que se inoculan con diez ml de sangre y 66,70 por ciento afirmó que se debe comenzar por el aeróbico. El promedio de puntuación general fue de 64,25. Conclusiones: Los profesionales de enfermería mostraron un adecuado conocimiento, los guantes estériles fueron el medio de protección más utilizado, destaca el uso de alcohol 76 por ciento para la desinfección de la piel, diez mililitros es el volumen de sangre considerado a inocular en los frascos, existe adherencia a los protocolos de transporte y conservación de la muestra(AU)

Introduction: Blood culture is a simple test, but there is a risk of contamination due to an inadequate procedure, which many times can be related to malpractice of the nursing personnel. Objective: To assess the level of knowledge about the blood culture extraction technique in nurses of an intensive care unit. Methods: A descriptive and cross-sectional study was carried out in the intensive care unit of the National Center for Minimal Access Surgery, Havana, in January 2021. The population consisted of twelve registered nurses. A knowledge questionnaire was applied, which included the following scoring scale: 0-30 points (no knowledge), 31-60 points (little knowledge), 61-90 points (adequate knowledge), 91-100 points (excellent knowledge). Absolute frequencies, percentage, T-test for one sample and chi-square were calculated. The program IBM SPSS (version 20) for Windows was used. Results: Of the sample studied, 41.70 percent considered that blood culture is performed on febrile patients and the use of sterile gloves as the only means of protection. 33.30 percent referred alcohol as the skin antiseptic of choice. 58.30 percent stated that test tube or flask inoculation is completed with 10 mL of blood. 66.70 percent stated that the technique should start with the aerobic. The average overall score was 64.25. Conclusions: Nursing professionals showed adequate knowledge. Sterile gloves were the most used means of protection. The use of 76 percent-alcohol for skin disinfection is relevant. The volume of blood to empty into the flask or sample tube is 10 mL. The protocols for sample preservation and transport are followed(AU)

Mapa Microbiológico - 2020 del Instituto de Hematología e Inmunología de Cuba / Microbiological Map

Introducción: Los mapas microbiológicos se consideran un marcador epidemiológico pues resumen estadísticamente las bacterias circulantes y su comportamiento frente a los antibióticos en uso. Permiten establecer una política de antibióticos que garantiza el uso más racional de los antimicrobianos y disminuye el riesgo de resistencia bacteriana. Objetivos: Identificar las bacterias aisladas con mayor frecuencia a partir de cultivos microbiológicos de pacientes hospitalizados en el Instituto de Hematología e Inmunología durante el año 2020 y determinar la resistencia de las bacterias más frecuentes a los antimicrobianos ensayados, con vista a establecer el primer mapa microbiológico de la institución. Métodos: Se realizó un estudio de corte transversal que incluyó los cultivos de pacientes hospitalizados durante el año 2020. La identificación bacteriana se realizó según métodos convencionales y para determinar los perfiles de resistencia se empleó el método de Bauer-Kirby. Resultados: El hemocultivo fue el estudio microbiológico más indicado con una positividad de 32,80 por ciento. Predominaron las bacterias Gram negativas (81,71 por ciento), siendo las más identificadas Pseudomonas spp., Enterobacter spp., Klebsiella spp. y Escherichia coli. Entre las bacterias Gram positivas predominó Staphylococcus spp. coagulasa negativa. Se obtuvieron elevados porcentajes de resistencia frente a casi todos los antimicrobianos evaluados. Conclusiones: La realización del mapa microbiológico de la institución permite actualizar la política de uso de los antimicrobianos al identificar a los bacilos Gram negativos, con elevados porcentajes de resistencia, como los principales agentes etiológicos de las infecciones registradas en este centro de salud durante el año 2020(AU)

Introduction: Microbiological maps are considered an epidemiological marker as statistically summarize circulating bacteria and their behavior against antibiotics in use. They allow establishing an antibiotic policy that guarantees the most rational use of antimicrobials and decreases the risk of bacterial resistance. Objectives: Identify the isolated bacteria with more frequency from microbiological crops of hospitalized patients in the Institute of Hematology and Immunology during the year 2020 and determine the resistance of the most frequent bacteria to the antimicrobials tested, with a view to establishing the first microbiological map of the institution. Methods: An observational, descriptive, cross-sectional study was performed that included cultures of patients hospitalized during the year 2020. Bacterial identification was carried out according to conventional methods and to determine the resistance profiles was used by the Bauer-Kirby method. Results: The blood culture was the most indicated microbiological study with 32.80 percent positivity. The Gram negative bacteria predominated (81.71percent), being the most identified Pseudomona spp., Enterobacter spp., Klebsiella spp. and Escherichia coli. Among the Gram positive bacteria predominate Staphylococcus spp. coagulase negative. High percentages of resistance were obtained in front of almost all antimicrobials evaluated. Conclusions: The completion of the institutional microbiological map allows updating the antimicrobial use policy by identifying the Gram negative bacilli, with high percentages of resistance, as the main etiological agents of the infections registered in this health center during 2020(AU)

Identificación directa de microorganismos a partir de hemocultivos positivos utilizando espectrometría de masas (MALDI-TOF MS) / Direct identification of microorganisms in positive blood culture bottles by mass spectrometry (MALDI-TOF MS)

Resumen La espectrometría de masas (MALDI-TOF MS) permite la identificación de microorganismos directamente de las colonias en pocos minutos. En este estudio se ha desarrollado y evaluado un protocolo reducido para identificar microorganismos directamente de las botellas de hemocultivos positivos en 30 minutos con una alta sensibilidad y especificidad, utilizando MALDITOF. Un total de 2535 hemocultivos positivos fueron estudiados por el método directo de MALDI-TOF MS, a partir de una alícuota de sangre de las botellas y el método de colonia, utilizando los cultivos desarrollados en medios sólidos. Del total de hemocultivos positivos incluidos en este estudio, 2381 (93,9%) fueron monomicrobianos y 146 (5,8%) polimicrobianos. Mil trescientos treinta (55,9%) de los aislamientos correspondieron a cocos gram positivos, 922 (38,7%) a bacilos gram negativos, 60 (2,5%) a anaerobios, 36 (1,5%) a bacilos gram positivos y 13 a levaduras. La concordancia global entre ambos métodos fue del 81,7% a nivel de especie (90,0% para bacilos gram negativos, 76,7% para cocos gram positivos y 33,3% para bacilos gram positivos). Se identificó al menos un germen en el 88% de las botellas positivas con desarrollo polimicrobiano. Los resultados del presente estudio demostraron que el protocolo basado en MALDI-TOF MS permite la identificación microbiana directamente de hemocultivos positivos en un tiempo corto, con una alta precisión, con excepción de los bacilos gram positivos.

Abstract Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) enables the identification of microorganisms directly from colonies within minutes. In this study this technology was adapted and tested for use with blood culture bottles, thus allowing identification in 30 minutes once the blood culture is detected as positive by the automate. A total of 2535 blood culture bottles reported as positive were tested by MALDI-TOF MS directly from positive blood culture bottles and colonies. A total of 2381 (93.9%) and 146 (5.8%) of the positive blood cultures were monomicrobial and polymicrobial, respectively. And 1330 (55.9%), 922 (38.7%), 60 (2.5%), 36 (1.5%) and 13 of the isolates were gram-positive cocci (GPC), gram-negative bacilli (GNB), anaerobic bacteria, gram-positive bacilli (GPB) and yeast respectively. Concordance between both methods was 81.7% (76.7% of GPC, 90% of GNB, 74.2% of anaerobic bacteria and 33.3% of GPB) in monomicrobial cultures. Eighty eight per cent of the polymicrobial cultures were identified correctly in at least one of the two bacteria. The results of the present study show that this fast, MALDI-TOF MS based method allows microbial identification directly from positive blood culture in a short time, with a high accuracy, with the exception of gram-positive bacilli.

Resumo A espectrometria de massa (MALDI-TOF MS) permite a identificação de microorganismos diretamente das colônias em minutos. Nesse estudo, foi desenvolvido um protocolo reduzido para identificar microrganismos diretamente das garrafas de hemoculturas positivas em 30 minutos com alta sensibilidade e especificidade, utilizando MALDI-TOF. Um total de 2535 hemoculturas positivas foram relatadas -o método direto de MALDI-TOF MS, a partir de uma alíquota de sangue dos vidros e o método de colônia, a partir das culturas desenvolvidas em meios sólidos. Do total de hemoculturas positivas incluídas neste estudo, 2.381 (93,9%) eram monomicrobianas e 146 (5,8%) eram polimicrobianas. Mil trezentos e trinta (55,9%) dos isolados corresponderam a cocos gram-positivos, 922 (38,7%) bacilos gram-negativos, 60 (2,5%) anaeróbios, 36 (1,5%) bacilos gram-positivos e 13 leveduras. A concordância geral entre os dois métodos foi de 81,7% em nivel de especie (90,0% para bacilos gram-negativos, 76,7% para cocos gram-positivos e 33,3% para bacilos gram-positivos). Pelo menos um germe foi identificado em 88% dos vidros positivos com desenvolvimento polimicrobiano. Os resultados do presente estudo demonstraram que o protocolo baseado em MALDI-TOF MS permite a identificação microbiana diretamente de hemoculturas positivas em um curto espaço de tempo, com alta precisão, com exceção de bacilos gram-positivos.