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1.
Curr Microbiol ; 81(8): 261, 2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-38981918

RESUMO

A reliable and above all, rapid antimicrobial susceptibility test (AST) is required for the diganostics of blood stream infections (BSI). In this study, resistance testing using DxM MicroScan WalkAway (MicroScan) from a 4-h subculture is compared with the standard overnight culture (18-24 h). Randomly selected positive blood cultures (PBC, n = 102) with gram-negative bacteria were included in the study. PBC were sub-cultured onto appropriate agar plates and AST by MicroScan was performed after 4 h of incubation and repeated after incubation for 18-24 h as standard. In a total of 1909 drug-strain pairs, the 4-h subculture approach showed a very high essential agreement (EA) (98.6%) and categorical agreement (CA) (97.1%) compared with the standard. The incidence of minor error (mE), major error (ME), very major error (VME), and adjusted very major error (aVME) was 1.1%, 0.4%, 12.9%, and 5.3%, respectively. In summary, the use of 4-h subcultures for resistance testing with the MicroScan offers a very reliable and easy to realize time saving when testing positive blood cultures with gram-negative bacteria.


Assuntos
Antibacterianos , Hemocultura , Bactérias Gram-Negativas , Testes de Sensibilidade Microbiana , Testes de Sensibilidade Microbiana/métodos , Humanos , Hemocultura/métodos , Antibacterianos/farmacologia , Bactérias Gram-Negativas/efeitos dos fármacos , Bacteriemia/microbiologia , Fatores de Tempo , Infecções por Bactérias Gram-Negativas/microbiologia
2.
BMC Pediatr ; 24(1): 438, 2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-38982359

RESUMO

BACKGROUND: Recovering pathogenic bacteria and yeast from pediatric blood cultures and reliably distinguishing between pathogens and contaminants are likely to be improved by increasing the volume of blood submitted to microbiology laboratories for culturing beyond the low volumes that have historically have been used. The primary aim of this study was to assess whether the pathogen recovery rate would increase after implementation of a weight-based algorithm for determining the intended volume of blood submitted for culturing. Secondary aims were to: 1) evaluate the effects of the algorithm implementation on the blood culture contamination rate; 2) determine whether pathogens might be found more often than contaminants in several as opposed to single bottles when more than one bottle is submitted; and 3) describe the microbiological findings for pathogens and contaminants in blood cultures by applying a clinical validation of true blood culture positivity. METHODS: A pre-post comparison of positivity and contamination rates after increasing the theoretical blood volume and number of blood culture bottles was performed, on the basis of a clinical validation of blood culture findings as pathogens vs contaminants. RESULTS: We examined 5327 blood cultures, including 186 with growth (123 true positives and 63 contaminated). The rate of true positive blood cultures significantly increased from 1.6% (42/2553) pre to 2.9% (81/2774, p = .002) post intervention. The rate of contaminated blood cultures did not change significantly during the study period (1.4% [35/2553] pre vs 1.0% [28/2774], p = .222) post intervention), but the proportion of contaminated cultures among all positive cultures decreased from 45% (35/77) pre to 26% (28/109, p = .005) post intervention. A microorganism that grew in a single bottle was considered a contaminant in 35% (8/23) of cases, whereas a microorganism that grew in at least two bottles was considered a contaminant in 2% (1/49, p < .001) of cases. According to common classification criteria relying primarily on the identity of the microorganism, 14% (17/123) of the recovered pathogens would otherwise have been classified as contaminants. CONCLUSION: Implementation of a weight-based algorithm to determine the volume and number of blood cultures in pediatric patients is associated with an increase in the pathogen recovery rate.


Assuntos
Algoritmos , Hemocultura , Humanos , Hemocultura/métodos , Criança , Pré-Escolar , Peso Corporal , Lactente , Masculino , Feminino , Recém-Nascido , Bacteriemia/diagnóstico , Bacteriemia/microbiologia
3.
Crit Care Explor ; 6(7): e1115, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38968174

RESUMO

OBJECTIVES: Our study aimed to assess the time to positivity (TTP) of clinically significant blood cultures in critically ill children admitted to the PICU. DESIGN: Retrospective review of positive blood cultures in patients admitted or transferred to the PICU. SETTING: Large tertiary-care medical center with over 90 PICU beds. PATIENTS: Patients 0-20 years old with bacteremia admitted or transferred to the PICU. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The primary endpoint was the TTP, defined as time from blood culture draw to initial Gram stain result. Secondary endpoints included percentage of cultures reported by elapsed time, as well as the impact of pathogen and host immune status on TTP. Host immune status was classified as previously healthy, standard risk, or immunocompromised. Linear regression for TTP was performed to account for age, blood volume, and Gram stain. Among 164 episodes of clinically significant bacteremia, the median TTP was 13.3 hours (interquartile range, 10.7-16.8 hr). Enterobacterales, Staphylococcus aureus, Streptococcus agalactiae, and Streptococcus pneumoniae were most commonly identified. By 12, 24, 36, and 48 hours, 37%, 89%, 95%, and 97% of positive cultures had resulted positive, respectively. Median TTP stratified by host immune status was 13.2 hours for previously healthy patients, 14.0 hours for those considered standard risk, and 10.6 hours for immunocompromised patients (p = 0.001). Median TTP was found to be independent of blood volume. No difference was seen in TTP for Gram-negative vs. Gram-positive organisms (12.2 vs. 13.9 hr; p = 0.2). CONCLUSIONS: Among critically ill children, 95% of clinically significant blood cultures had an initial positive result within 36 hours, regardless of host immune status. Need for antimicrobial therapy should be frequently reassessed and implementation of a shorter duration of empiric antibiotics should be considered in patients with low suspicion for infection.


Assuntos
Bacteriemia , Hemocultura , Estado Terminal , Unidades de Terapia Intensiva Pediátrica , Humanos , Pré-Escolar , Unidades de Terapia Intensiva Pediátrica/estatística & dados numéricos , Estudos Retrospectivos , Criança , Lactente , Bacteriemia/diagnóstico , Bacteriemia/microbiologia , Bacteriemia/sangue , Masculino , Feminino , Adolescente , Fatores de Tempo , Recém-Nascido , Adulto Jovem
4.
Front Immunol ; 15: 1397941, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38933274

RESUMO

Introduction: The diagnosis of tuberculosis (TB) disease and TB infection (TBI) remains a challenge, and there is a need for non-invasive and blood-based methods to differentiate TB from conditions mimicking TB (CMTB), TBI, and healthy controls (HC). We aimed to determine whether combination of cytokines and established biomarkers could discriminate between 1) TB and CMTB 2) TB and TBI 3) TBI and HC. Methods: We used hemoglobin, total white blood cell count, neutrophils, monocytes, C-reactive protein, and ten Meso Scale Discovery analyzed cytokines (interleukin (IL)-1ß, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p70, IL-13, interferon (IFN)-É£, and tumor necrosis factor (TNF)-α) in TruCulture whole blood tubes stimulated by lipopolysaccharides (LPS), zymosan (ZYM), anti-CD3/28 (CD3), and unstimulated (Null) to develop three index tests able to differentiate TB from CMTB and TBI, and TBI from HC. Results: In 52 persons with CMTB (n=9), TB (n=23), TBI (n=10), and HC (n=10), a combination of cytokines (LPS-IFN-É£, ZYM-IFN-É£, ZYM-TNF-α, ZYM-IL-1ß, LPS-IL-4, and ZYM-IL-6) and neutrophil count could differentiate TB from CMTB with a sensitivity of 52.2% (95% CI: 30.9%-73.4%) and a specificity of 100 % (66.4%-100%). Null- IFN-É£, Null-IL-8, CD3-IL-6, CD3-IL-8, CD3-IL-13, and ZYM IL-1b discriminated TB from TBI with a sensitivity of 73.9% (56.5% - 91.3%) and a specificity of 100% (69.2-100). Cytokines and established biomarkers failed to differentiate TBI from HC with ≥ 98% specificity. Discussion: Selected cytokines may serve as blood-based add-on tests to detect TB in a low-endemic setting, although these results need to be validated.


Assuntos
Biomarcadores , Hemocultura , Citocinas , Tuberculose , Humanos , Citocinas/sangue , Masculino , Feminino , Adulto , Biomarcadores/sangue , Tuberculose/diagnóstico , Tuberculose/imunologia , Tuberculose/sangue , Pessoa de Meia-Idade , Diagnóstico Diferencial , Adulto Jovem , Idoso , Mycobacterium tuberculosis/imunologia , Sensibilidade e Especificidade
5.
Front Cell Infect Microbiol ; 14: 1358801, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38895732

RESUMO

Background: Rapid and accurate diagnosis of the causative agents is essential for clinical management of bloodstream infections (BSIs) that might induce sepsis/septic shock. A considerable number of suspected sepsis patients initially enter the health-care system through an emergency department (ED), hence it is vital to establish an early strategy to recognize sepsis and initiate prompt care in ED. This study aimed to evaluate the diagnostic performance and clinical value of droplet digital PCR (ddPCR) assay in suspected sepsis patients in the ED. Methods: This was a prospective single-centered observational study including patients admitted to the ED from 25 October 2022 to 3 June 2023 with suspected BSIs screened by Modified Shapiro Score (MSS) score. The comparison between ddPCR and blood culture (BC) was performed to evaluate the diagnostic performance of ddPCR for BSIs. Meanwhile, correlative analysis between ddPCR and the inflammatory and prognostic-related biomarkers were conducted to explore the relevance. Further, the health economic evaluation of the ddPCR was analyzed. Results: 258 samples from 228 patients, with BC and ddPCR performed simultaneously, were included in this study. We found that ddPCR results were positive in 48.13% (103 of 214) of episodes, with identification of 132 pathogens. In contrast, BC only detected 18 positives, 88.89% of which were identified by ddPCR. When considering culture-proven BSIs, ddPCR shows an overall sensitivity of 88.89% and specificity of 55.61%, the optimal diagnostic power for quantifying BSI through ddPCR is achieved with a copy cutoff of 155.5. We further found that ddPCR exhibited a high accuracy especially in liver abscess patients. Among all the identified virus by ddPCR, EBV has a substantially higher positive rate with a link to immunosuppression. Moreover, the copies of pathogens in ddPCR were positively correlated with various markers of inflammation, coagulation, immunity as well as prognosis. With high sensitivity and specificity, ddPCR facilitates precision antimicrobial stewardship and reduces health care costs. Conclusions: The multiplexed ddPCR delivers precise and quantitative load data on the causal pathogen, offers the ability to monitor the patient's condition and may serve as early warning of sepsis in time-urgent clinical situations as ED. Importance: Early detection and effective administration of antibiotics are essential to improve clinical outcomes for those with life-threatening infection in the emergency department. ddPCR, an emerging tool for rapid and sensitive pathogen identification used as a precise bedside test, has developed to address the current challenges of BSI diagnosis and precise treatment. It characterizes sensitivity, specificity, reproducibility, and absolute quantifications without a standard curve. ddPCR can detect causative pathogens and related resistance genes in patients with suspected BSIs within a span of three hours. In addition, it can identify polymicrobial BSIs and dynamically monitor changes in pathogenic microorganisms in the blood and can be used to evaluate antibiotic efficacy and survival prognosis. Moreover, the copies of pathogens in ddPCR were positively correlated with various markers of inflammation, coagulation, immunity. With high sensitivity and specificity, ddPCR facilitates precision antimicrobial stewardship and reduces health care costs.


Assuntos
Diagnóstico Precoce , Serviço Hospitalar de Emergência , Reação em Cadeia da Polimerase , Sepse , Humanos , Estudos Prospectivos , Sepse/diagnóstico , Sepse/microbiologia , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Reação em Cadeia da Polimerase/métodos , Sensibilidade e Especificidade , Biomarcadores/sangue , Hemocultura/métodos , Adulto
6.
BMC Infect Dis ; 24(1): 566, 2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38844852

RESUMO

BACKGROUND: Early and appropriate antibiotic treatment improves the clinical outcome of patients with sepsis. There is an urgent need for rapid identification (ID) and antimicrobial susceptibility testing (AST) of bacteria that cause bloodstream infection (BSI). Rapid ID and AST can be achieved by short-term incubation on solid medium of positive blood cultures using MALDI-TOF mass spectrometry (MS) and the BD M50 system. The purpose of this study is to evaluate the performance of rapid method compared to traditional method. METHODS: A total of 124 mono-microbial samples were collected. Positive blood culture samples were short-term incubated on blood agar plates and chocolate agar plates for 5 ∼ 7 h, and the rapid ID and AST were achieved through Zybio EXS2000 MS and BD M50 System, respectively. RESULTS: Compared with the traditional 24 h culture for ID, this rapid method can shorten the cultivation time to 5 ∼ 7 h. Accurate organism ID was achieved in 90.6% of Gram-positive bacteria (GP), 98.5% of Gram-negative bacteria (GN), and 100% of fungi. The AST resulted in the 98.5% essential agreement (EA) and 97.1% category agreements (CA) in NMIC-413, 99.4% EA and 98.9% CA in PMIC-92, 100% both EA and CA in SMIC-2. Besides, this method can be used for 67.2% (264/393) of culture bottles during routine work. The mean turn-around time (TAT) for obtaining final results by conventional method is approximately 72.6 ± 10.5 h, which is nearly 24 h longer than the rapid method. CONCLUSIONS: The newly described method is expected to provide faster and reliable ID and AST results, making it an important tool for rapid management of blood cultures (BCs). In addition, this rapid method can be used to process most positive blood cultures, enabling patients to receive rapid and effective treatment.


Assuntos
Bactérias , Testes de Sensibilidade Microbiana , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Humanos , Testes de Sensibilidade Microbiana/métodos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Bactérias/efeitos dos fármacos , Bactérias/isolamento & purificação , Antibacterianos/farmacologia , Fungos/efeitos dos fármacos , Fungos/isolamento & purificação , Hemocultura/métodos , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Negativas/isolamento & purificação , Fatores de Tempo , Bactérias Gram-Positivas/efeitos dos fármacos , Bactérias Gram-Positivas/isolamento & purificação , Sepse/microbiologia , Sepse/tratamento farmacológico , Sepse/diagnóstico
8.
BMJ Open ; 14(5): e084053, 2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38821574

RESUMO

INTRODUCTION: The liberal use of blood cultures in emergency departments (EDs) leads to low yields and high numbers of false-positive results. False-positive, contaminated cultures are associated with prolonged hospital stays, increased antibiotic usage and even higher hospital mortality rates. This trial aims to investigate whether a recently developed and validated machine learning model for predicting blood culture outcomes can safely and effectively guide clinicians in withholding unnecessary blood culture analysis. METHODS AND ANALYSIS: A randomised controlled, non-inferiority trial comparing current practice with a machine learning-guided approach. The primary objective is to determine whether the machine learning based approach is non-inferior to standard practice based on 30-day mortality. Secondary outcomes include hospital length-of stay and hospital admission rates. Other outcomes include model performance and antibiotic usage. Participants will be recruited in the EDs of multiple hospitals in the Netherlands. A total of 7584 participants will be included. ETHICS AND DISSEMINATION: Possible participants will receive verbal information and a paper information brochure regarding the trial. They will be given at least 1 hour consideration time before providing informed consent. Research results will be published in peer-reviewed journals. This study has been approved by the Amsterdam University Medical Centers' local medical ethics review committee (No 22.0567). The study will be conducted in concordance with the principles of the Declaration of Helsinki and in accordance with the Medical Research Involving Human Subjects Act, General Data Privacy Regulation and Medical Device Regulation. TRIAL REGISTRATION NUMBER: NCT06163781.


Assuntos
Hemocultura , Serviço Hospitalar de Emergência , Aprendizado de Máquina , Humanos , Hemocultura/métodos , Países Baixos , Mortalidade Hospitalar , Estudos de Equivalência como Asunto , Tempo de Internação/estatística & dados numéricos , Ensaios Clínicos Controlados Aleatórios como Assunto , Procedimentos Desnecessários/estatística & dados numéricos , Antibacterianos/uso terapêutico
9.
Andes Pediatr ; 95(2): 143-150, 2024 Apr.
Artigo em Espanhol | MEDLINE | ID: mdl-38801361

RESUMO

Bacteremia is a major cause of morbidity and mortality in patients with cancer and episodes of high-risk febrile neutropenia (HRFN). OBJECTIVE: To identify the frequency of microorganisms isolated from blood cultures (BC) and their antimicrobial resistance (R) profile in children with HRFN, compared with the same data from previous studies of the same group. METHOD: Prospective, multicenter, epidemiological surveillance study of microorganisms isolated from BC in patients under 18 years of age, from 7 PINDA network hospitals, between 2016 and 2021. RESULTS: 284 episodes of HRFN with positive BC were analyzed out of 1091 enrolled episodes (26%). Median age 7.2 years [3.0-12.3]. The main isolates were gram-negative bacilli (GNB) 49.2%, gram-positive cocci (GPC) 43.8%, and fungi 3.6%. The most frequently isolated microorganisms were viridans group Streptococci (VGS) (25.8%), Escherichia coli (19.8%), Pseudomonas spp. (11.2%), Klebsiella spp. (10.9%), and coagulase negative Staphylococci (CoNS) (10.9%). There was an increase in R to third-generation cephalosporins (p = 0.011) in GNB and to oxacillin in CoNS (p = 0.00), as well as a decrease in R to amikacin in non-fermenting GNB (p = 0.02) and to penicillin in VGS (p = 0.04). CONCLUSION: VGS is the main agent isolated in BC from pediatric patients with cancer and episodes of HRFN, followed by E. coli, Pseudomonas spp., and Klebsiella spp. Having epidemiological surveillance of microorganisms isolated from BC and their antimicrobial R profile is essential to favor the rational use of antimicrobials.


Assuntos
Antibacterianos , Bacteriemia , Hemocultura , Neutropenia Febril , Neoplasias , Humanos , Criança , Neoplasias/microbiologia , Estudos Prospectivos , Pré-Escolar , Neutropenia Febril/microbiologia , Neutropenia Febril/tratamento farmacológico , Chile/epidemiologia , Bacteriemia/microbiologia , Bacteriemia/epidemiologia , Bacteriemia/diagnóstico , Feminino , Masculino , Antibacterianos/uso terapêutico , Antibacterianos/farmacologia , Farmacorresistência Bacteriana , Testes de Sensibilidade Microbiana , Adolescente , Bactérias Gram-Negativas/isolamento & purificação , Bactérias Gram-Negativas/efeitos dos fármacos
10.
Surg Infect (Larchmt) ; 25(4): 335-337, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38696669

RESUMO

Background: Raoultella planticola is an uncommon gram-negative organism found in the environment. Patients and Methods: The patient, an 81-year-old female who had undergone total cystectomy and bilateral ureteral stoma surgery, presented to the hospital with a fever. It was determined that Raoultella planticola was responsible for the bacteremia. Results: Rapid identification of bacteria using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) in blood culture samples and appropriate antibacterial treatment was begun and the patient was discharged three days later. Conclusions: This case emphasizes the presence of a rare pathogen as the cause of bacteremia and underscores the importance of utilizing rapid methods for bacterial identification to establish an accurate diagnosis.


Assuntos
Antibacterianos , Bacteriemia , Hemocultura , Infecções por Enterobacteriaceae , Enterobacteriaceae , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Humanos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Feminino , Bacteriemia/diagnóstico , Bacteriemia/microbiologia , Idoso de 80 Anos ou mais , Enterobacteriaceae/isolamento & purificação , Infecções por Enterobacteriaceae/diagnóstico , Infecções por Enterobacteriaceae/microbiologia , Hemocultura/métodos , Antibacterianos/uso terapêutico
11.
J Korean Med Sci ; 39(17): e157, 2024 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-38711319

RESUMO

This study assessed the performance of the BioFire Blood Culture Identification 2 (BCID2) panel in identifying microorganisms and antimicrobial resistance (AMR) profiles in positive blood cultures (BCs) and its influence on turnaround time (TAT) compared with conventional culture methods. We obtained 117 positive BCs, of these, 102 (87.2%) were correctly identified using BCID2. The discordance was due to off-panel pathogens detected by culture (n = 13), and additional pathogens identified by BCID2 (n = 2). On-panel pathogen concordance between the conventional culture and BCID2 methods was 98.1% (102/104). The conventional method detected 19 carbapenemase-producing organisms, 14 extended-spectrum beta-lactamase-producing Enterobacterales, 18 methicillin-resistant Staphylococcus spp., and four vancomycin-resistant Enterococcus faecium. BCID2 correctly predicted 53 (96.4%) of 55 phenotypic resistance patterns by detecting AMR genes. The TAT for BCID2 was significantly lower than that for the conventional method. BCID2 rapidly identifies pathogens and AMR genes in positive BCs.


Assuntos
Hemocultura , Reação em Cadeia da Polimerase Multiplex , Reação em Cadeia da Polimerase Multiplex/métodos , Humanos , Testes de Sensibilidade Microbiana , Farmacorresistência Bacteriana/genética , Proteínas de Bactérias/genética , beta-Lactamases/genética , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Enterococcus faecium/genética , Enterococcus faecium/isolamento & purificação , Bactérias/genética , Bactérias/isolamento & purificação , Bactérias/efeitos dos fármacos , Enterococos Resistentes à Vancomicina/genética , Enterococos Resistentes à Vancomicina/isolamento & purificação , Bacteriemia/microbiologia , Bacteriemia/diagnóstico
12.
Int J Mol Sci ; 25(10)2024 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-38791501

RESUMO

Sepsis is a life-threatening syndrome triggered by infection and accompanied by high mortality, with antimicrobial resistances (AMRs) further escalating clinical challenges. The rapid and reliable detection of causative pathogens and AMRs are key factors for fast and appropriate treatment, in order to improve outcomes in septic patients. However, current sepsis diagnostics based on blood culture is limited by low sensitivity and specificity while current molecular approaches fail to enter clinical routine. Therefore, we developed a suppression PCR-based selective enrichment sequencing approach (SUPSETS), providing a molecular method combining multiplex suppression PCR with Nanopore sequencing to identify most common sepsis-causative pathogens and AMRs using plasma cell-free DNA. Applying only 1 mL of plasma, we targeted eight pathogens across three kingdoms and ten AMRs in a proof-of-concept study. SUPSETS was successfully tested in an experimental research study on the first ten clinical samples and revealed comparable results to clinical metagenomics while clearly outperforming blood culture. Several clinically relevant AMRs could be additionally detected. Furthermore, SUPSETS provided first pathogen and AMR-specific sequencing reads within minutes of starting sequencing, thereby potentially decreasing time-to-results to 11-13 h and suggesting diagnostic potential in sepsis.


Assuntos
Ácidos Nucleicos Livres , Sepse , Humanos , Sepse/diagnóstico , Sepse/microbiologia , Sepse/sangue , Ácidos Nucleicos Livres/sangue , Farmacorresistência Bacteriana/genética , Hemocultura/métodos , DNA Bacteriano/genética , Reação em Cadeia da Polimerase Multiplex/métodos , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Bactérias/genética , Bactérias/isolamento & purificação , Reação em Cadeia da Polimerase/métodos , Sequenciamento por Nanoporos/métodos
13.
J Clin Lab Anal ; 38(9): e25043, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38804639

RESUMO

BACKGROUND: Rapid antimicrobial susceptibility testing (AST) for bloodstream infections (BSIs) facilitates the optimization of antimicrobial therapy, preventing antimicrobial resistance and improving patient outcomes. QMAC-dRAST (QuantaMatrix Inc., Korea) is a rapid AST platform based on microfluidic chip technology that performs AST directly using positive blood culture broth (PBCB). This study evaluated the performance of QMAC-dRAST for Gram-negative bacteria using PBCB and subcultured colony isolates, comparing it with that of VITEK 2 (bioMérieux, France) using broth microdilution (BMD) as the reference method. METHODS: We included 141 Gram-negative blood culture isolates from patients with BSI and 12 carbapenemase-producing clinical isolates of Enterobacterales spiked into blood culture bottles. QMAC-dRAST performance was evaluated using PBCB and colony isolates, whereas VITEK 2 and BMD were tested only on colony isolates. RESULTS: For PBCB, QMAC-dRAST achieved 92.1% categorical agreement (CA), 95.3% essential agreement (EA), with 1.8% very major errors (VMEs), 3.5% major errors (MEs), and 5.2% minor errors (mEs). With colony isolates, it exhibited 92.5% CA and 95.1% EA, with 2.0% VMEs, 3.2% MEs, and 4.8% mEs. VITEK 2 showed 94.1% CA and 96.0% EA, with 4.3% VMEs, 0.4% MEs, and 4.3% mEs. QMAC-dRAST yielded elevated error rates for specific antimicrobial agents, with high VMEs for carbapenems and aminoglycosides. The median time to result for QMAC-dRAST was 5.9 h for PBCB samples and 6.1 h for subcultured colony isolates. CONCLUSIONS: The QMAC-dRAST system demonstrated considerable strengths and comparable performance to the VITEK 2 system; however, challenges were discerned with specific antimicrobial agents, underlining a necessity for improvement.


Assuntos
Antibacterianos , Hemocultura , Bactérias Gram-Negativas , Testes de Sensibilidade Microbiana , Testes de Sensibilidade Microbiana/métodos , Humanos , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Negativas/isolamento & purificação , Hemocultura/métodos , Antibacterianos/farmacologia
14.
BMC Microbiol ; 24(1): 187, 2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38802760

RESUMO

BACKGROUND: Rapid antimicrobial susceptibility testing (AST) is urgently needed to provide safer treatment to counteract antimicrobial resistance. This is critical in septic patients, because resistance increases empiric therapy uncertainty and the risk of a poor outcome. We validate a novel 2h flow cytometry AST assay directly from positive blood cultures (PBC) by using a room temperature stable FASTgramneg and FASTgrampos kits (FASTinov® Porto, Portugal) in three sites: FASTinov (site-1), Hospital Ramon y Cajal, Madrid, Spain (site-2) and Centro Hospitalar S. João, Porto, Portugal (site-3). A total of 670 PBC were included: 333 spiked (site-1) and 337 clinical PBC (151 site-2 and 186 site-3): 367 gram-negative and 303 gram-positive. Manufacturer instructions were followed for sample preparation, panel inoculation, incubation (1h/37ºC) and flow cytometry analysis using CytoFlex (Site-1 and -2) or DxFlex (site-3) both instruments from Beckman-Coulter, USA. RESULTS: A proprietary software (bioFAST) was used to immediately generate a susceptibility report in less than 2 h. In parallel, samples were processed according to reference AST methods (disk diffusion and/or microdilution) and interpreted with EUCAST and CLSI criteria. Additionally, ten samples were spiked in all sites for inter-laboratory reproducibility. Sensitivity and specificity were >95% for all antimicrobials. Reproducibility was 96.8%/95.0% for FASTgramneg and 95.1%/95.1% for FASTgrampos regarding EUCAST/CLSI criteria, respectively. CONCLUSION: FASTinov® kits consistently provide ultra-rapid AST in 2h with high accuracy and reproducibility on both Gram-negative and Gram-positive bacteria. This technology creates a new paradigm in bacterial infection management and holds the potential to significantly impact septic patient outcomes and antimicrobial stewardship.


Assuntos
Antibacterianos , Hemocultura , Citometria de Fluxo , Testes de Sensibilidade Microbiana , Humanos , Citometria de Fluxo/métodos , Antibacterianos/farmacologia , Testes de Sensibilidade Microbiana/métodos , Testes de Sensibilidade Microbiana/instrumentação , Hemocultura/métodos , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Negativas/isolamento & purificação , Bactérias Gram-Positivas/efeitos dos fármacos , Bactérias Gram-Positivas/isolamento & purificação , Fatores de Tempo , Portugal , Espanha , Reprodutibilidade dos Testes
15.
Diagn Microbiol Infect Dis ; 109(3): 116269, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38692201

RESUMO

We assessed the performance of GenMark's ePlex® Blood Culture Identification (BCID) Panels for overall agreement of organism identification and resistance mechanism detection with standard microbiologic methods. This study included patients with a positive blood culture from May 2020 to January 2021. The primary outcomes were to assess concordance of ePlex® organism identification with standard identification methods and concordance of ePlex® genotypic resistance mechanism detection with standard phenotypic susceptibility testing. Secondary outcomes included panel specific performance and characterization of antimicrobial stewardship opportunities. The overall identification concordance rate in 1276 positive blood cultures was 98.1%. The overall concordance for the presence of resistance markers was 98.2% and concordance for the absence of resistance markers was 100%. A majority of ePlex® results (69.5%) represented opportunities for potential antimicrobial stewardship intervention. High concordance rates between the ePlex® BCID panels and standard identification and susceptibility methods enable utilization of results to guide rapid antimicrobial optimization.


Assuntos
Antibacterianos , Gestão de Antimicrobianos , Hemocultura , Testes de Sensibilidade Microbiana , Humanos , Hemocultura/métodos , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Bactérias/efeitos dos fármacos , Bactérias/isolamento & purificação , Bactérias/genética , Bactérias/classificação , Farmacorresistência Bacteriana/genética , Bacteriemia/microbiologia , Bacteriemia/diagnóstico , Bacteriemia/tratamento farmacológico , Genótipo
16.
Diagn Microbiol Infect Dis ; 109(3): 116335, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38703531

RESUMO

OBJECTIVES: The objective of this study was to provide the clinic with rapid and accurate results of antimicrobial susceptibility testing for the treatment of patients with bloodstream infections. To achieve this, we applied the Clinical and Laboratory Standards Institute (CLSI) blood culture direct rapid antimicrobial susceptibility test (rAST) to assess the susceptibility of the most common Enterobacterales found in blood cultures. METHODS: In this study, we utilized the CLSI blood culture direct rapid antimicrobial susceptibility test to assess the susceptibility (rAST) of the most common Enterobacterales present in blood cultures. We chose this method for its simplicity in analysis, and our aim was to predict minimum inhibitory concentrations (MICs) using the rAST. As a benchmark, we assumed that Broth Macrodilution method (BMD) results were 100% accurate. For data evaluation, we employed the terms categorical agreement (CA), very major errors (VME), and major errors (ME). RESULTS: Our findings demonstrate that the CLSI rAST method is reliable for rapidly determining the in vitro susceptibility of Enterobacterales to common antimicrobial drugs in bloodstream infections. We achieved a concordance rate of 90% in classification within a 10-hour timeframe. We identified a total of 112 carbapenem-resistant Enterobacterales (CRE) strains, and there was no significant difference in the detection rate of CRE at 6, 10, and 16 hours. This suggests that CRE can be identified as early as 6 hours. CONCLUSION: The CLSI rAST is a valuable tool that can be utilized in clinical practice to quickly determine the susceptibility of Enterobacterales to antimicrobial drugs within 10 hours. This capability can greatly assist in the clinical management of patients with bloodstream infections.


Assuntos
Antibacterianos , Hemocultura , Infecções por Enterobacteriaceae , Enterobacteriaceae , Testes de Sensibilidade Microbiana , Humanos , Testes de Sensibilidade Microbiana/normas , Testes de Sensibilidade Microbiana/métodos , Hemocultura/métodos , Enterobacteriaceae/efeitos dos fármacos , Antibacterianos/farmacologia , Infecções por Enterobacteriaceae/microbiologia , Infecções por Enterobacteriaceae/tratamento farmacológico , Bacteriemia/microbiologia , Bacteriemia/tratamento farmacológico
17.
Diagn Microbiol Infect Dis ; 109(3): 116306, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38735146

RESUMO

Rapid identification of microbial pathogens "directly" from positive blood cultures (PBCs) is critical for prompt initiation of empirical antibiotic therapy and clinical outcomes. Towards higher microbial identification rates, we modified a published initial serum separator tubes-based MALDI-TOF-MS protocol, for blood culture specimens received at a non-hospital based standalone diagnostic laboratory, Bangalore, India: (a) "Initial" protocol #1: From 28 PBCs, identification= 39% (Gram-negative= 43%: Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa; Gram-positive: 36%: Enterococcus faecalis, Staphylococcus aureus, Staphylococcus haemolyticus); mis-identification= 14%; non-identification= 47%. (b) "Modified" protocol #2: Quality controls (ATCC colonies spiked in negative blood cultures) From 7 analysis, identification= 100% (Escherichia coli, Klebsiella pneumonia, Klebsiella oxytoca, Pseudomonas aeruginosa, Enterococcus faecalis, Staphylococcus aureus); From 7 PBCs, identification= 57%; mis-identification= 14%; non-identification= 29%. Microbial preparations of highest quality and quantity for proteomic analysis and separate spectra matching reference databases for colonies and PBCs are needed for best clinical utility.


Assuntos
Hemocultura , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Humanos , Hemocultura/métodos , Índia , Bactérias/isolamento & purificação , Bactérias/classificação , Bacteriemia/diagnóstico , Bacteriemia/microbiologia
18.
J Microbiol Methods ; 221: 106940, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38702032

RESUMO

Bloodstream infections (BSI) caused by carbapenem-resistant Gram-negative bacilli (CR-GNB) are a subject of major clinical concern, mainly those associated with carbapenemase-producing isolates. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) has been proposed to detect specific ß-lactamases, including KPC. We aimed to detect KPC enzyme directly from positive blood cultures using MALDI-TOF MS. Overall, 146 clinical Gram-negative bacilli (46 CR-GNB) recovered from consecutive blood cultures were evaluated. Proteins were extracted using formic acid, isopropyl alcohol, and water and spotted onto a steel target plate using the double-layer sinapinic acid method. The relative ions intensity ≥120 arbitrary units (a.u.) of a peak close to 28,700 m/z indicated the presence of KPC. The results were compared to HRM-qPCR methodology. This specific peak was observed in 11/14 blood bottles with blaKPC positive isolates (78.6% sensitivity), with 3 false-positive results (97.7% specificity). Analysis from colonies reached identical sensitivity (78.6%), but higher specificity (100%). The detection of KPC peaks directly from positive blood cultures using MALDI-TOF MS is feasible and rapid. It's excellent specificity indicates that positive results are consistently associated with the presence of a KPC producer in positive blood culture.


Assuntos
Proteínas de Bactérias , Hemocultura , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , beta-Lactamases , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Humanos , beta-Lactamases/genética , Hemocultura/métodos , Proteínas de Bactérias/genética , Sensibilidade e Especificidade , Bactérias Gram-Negativas/isolamento & purificação , Bactérias Gram-Negativas/enzimologia , Bactérias Gram-Negativas/classificação , Bactérias Gram-Negativas/genética , Bacteriemia/microbiologia , Bacteriemia/diagnóstico , Infecções por Bactérias Gram-Negativas/microbiologia , Infecções por Bactérias Gram-Negativas/diagnóstico , Infecções por Bactérias Gram-Negativas/sangue , Antibacterianos/farmacologia , Carbapenêmicos/farmacologia
19.
World J Microbiol Biotechnol ; 40(7): 222, 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38811387

RESUMO

In this study, it was aimed to investigate bacterial contamination in apheresis platelet suspensions (APS) by automated blood culture system and flow cytometry method (FCM).33 spiked APS each using 11 bacterial strains (5 standard strains, 6 clinical isolates), were prepared in three different dilutions (1-10, 10-50, 50-100 cfu/mL), incubated in two different temperatures (35-37 °C and 22-24 °C) and different incubation times (18-96 h) evaluated by FCM. This three different dilutions were also inoculated into special platelet culture bottles (BacT/ALERT® BPA) and loaded into the blood culture system. Additionally 80 APSs routinely prepared in the Transfusion Center were evaluated by both FCM and the blood culture system. Platelets were lysed by freeze-thaw method.All spiked samples were positive with BacT/ALERT® BPA in 12-18 h. In 96 h incubation at 22-24 °C, the presence of bacteria was detected by FCM in all other samples (31/33) except low dilutions (1-10 and 10-100 CFU/ml) of K.pneumoniae standard strain. In the 35-37 °C, the presence of bacteria was detected by FCM in all samples (33/33) after 48 h of incubation. In routine APS one sample detected as positive (Bacillus simplex) with BacT/ALERT® BPA and no positivity was detected by FCM.The freeze-thaw method, which we have optimized for the lysis of platelets, is very practical and can be easily applied. The BacT/ALERT® system has been found to be very sensitive in detecting bacterial contamination in PSs. Flow cytometry method has been found to be successful, fast, easy to use and low cost in detecting bacterial contamination in PSs.


Assuntos
Plaquetas , Segurança do Sangue , Citometria de Fluxo , Segurança do Sangue/instrumentação , Segurança do Sangue/métodos , Plaquetas/microbiologia , Citometria de Fluxo/normas , Remoção de Componentes Sanguíneos , Hemocultura/normas , Bactérias/isolamento & purificação , Humanos , Sensibilidade e Especificidade
20.
Int J Antimicrob Agents ; 63(6): 107176, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38642811

RESUMO

OBJECTIVES: Optimising blood culture processing is important to ensure that bloodstream infections are accurately diagnosed while minimising adverse events caused by antibiotic abuse. This study aimed to evaluate the impact of optimised blood culture processes on antibiotic use, clinical outcomes and economics in intensive care unit (ICU) patients with positive blood cultures. METHODS: From March 2020 to October 2021, this microbiology laboratory implemented a series of improvement measures, including the clinical utility of Fastidious Antimicrobial Neutralization (FAN® PLUS) bottles for the BacT/Alert Virtuo blood culture system, optimisation of bottle reception, graded reports and an upgraded laboratory information system. A total of 122 ICU patients were included in the pre-optimisation group from March 2019 to February 2020, while 179 ICU patients were included in the post-optimisation group from November 2021 to October 2022. RESULTS: Compared with the pre-optimisation group, the average reporting time of identification and antimicrobial sensitivity was reduced by 16.72 hours in the optimised group. The time from admission to targeted antibiotic therapy within 24 hours after receiving both the Gram stain report and the final report were both significantly less in the post-optimisation group compared with the pre-optimisation group. The average hospitalisation time was reduced by 6.49 days, the average antimicrobial drug cost lowered by $1720.85 and the average hospitalisation cost by $9514.17 in the post-optimisation group. CONCLUSIONS: Optimising blood culture processing was associated with a significantly increased positive detection rate, a remarkable reduction in the length of hospital stay and in hospital costs for ICU patients with bloodstream infections.


Assuntos
Antibacterianos , Hemocultura , Estado Terminal , Unidades de Terapia Intensiva , Humanos , Hemocultura/métodos , Hemocultura/economia , Masculino , Feminino , Pessoa de Meia-Idade , Antibacterianos/uso terapêutico , Antibacterianos/economia , Idoso , Bacteriemia/diagnóstico , Bacteriemia/tratamento farmacológico , Bacteriemia/economia , Bacteriemia/microbiologia , Adulto , Tempo de Internação , Testes de Sensibilidade Microbiana/economia , Testes de Sensibilidade Microbiana/métodos
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