scholarly journals Rapid Diagnosis of Bacteremia in Adults Using Acridine Orange Stained Buffy Coat Smears

1990 ◽  
Vol 1 (1) ◽  
pp. 7-10
Author(s):  
Mark Miller ◽  
Jack Mendelson
Keyword(s):  
Blood Culture ◽  
Acridine Orange ◽  
Buffy Coat ◽  
Blood Cultures ◽  
Rapid Screening ◽  
Blood Culture System ◽  
Blood Samples ◽  
Significant Difference ◽  
Rapid Screening Test ◽  
Low Sensitivity

The use of acridine orange stained buffy coat smears was assessed as a rapid screening test for bacteremia in adults. A total of 356 consecutive blood cultures were submitted with simultaneous anticoagulated blood samples, from which a buffy coat smear was prepared and stained with acridine orange (100 mg/L; pH 3.0). Forty-one of 356 blood samples (12%) yielded organisms in the blood culture system. Compared to blood culture, the overall sensitivity of acridine orange stained buffy coat smears was 16%, specificity 88%, and positive predictive value 13%. There was no statistically significant difference in performance of the test among patients who had fever greater than 39°C and/or shock. The low sensitivity and specificity of the test makes it unsuitable as a means of rapid screening for adults with suspected bacteremia.

scholarly journals Community-acquired bacteraemia in COVID-19 in comparison to influenza A and influenza B: a retrospective cohort study

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Julinha M. Thelen ◽  
A. G. ( Noud) Buenen ◽  
Marjan van Apeldoorn ◽  
Heiman F. Wertheim ◽  
Mirjam H. A. Hermans ◽  
...  
Keyword(s):  
Cohort Study ◽  
Blood Culture ◽  
The Netherlands ◽  
Retrospective Cohort Study ◽  
Retrospective Cohort ◽  
Influenza A ◽  
Blood Cultures ◽  
Influenza B ◽  
Significant Difference ◽  
All Cause Mortality

Abstract Background During the coronavirus disease 2019 (COVID-19) pandemic in the Netherlands it was noticed that very few blood cultures from COVID-19 patients turned positive with clinically relevant bacteria. This was particularly evident in comparison to the number of positive blood cultures during previous seasonal epidemics of influenza. This observation raised questions about the occurrence and causative microorganisms of bacteraemia in COVID-19 patients, especially in the perspective of the widely reported overuse of antibiotics and the rising rate of antibiotic resistance. Methods We conducted a retrospective cohort study on blood culture results in influenza A, influenza B and COVID-19 patients presenting to two hospitals in the Netherlands. Our main outcome consisted of the percentage of positive blood cultures. The percentage of clinically relevant blood cultures, isolated bacteria and 30-day all-cause mortality served as our secondary outcomes. Results A total of 1331 viral episodes were analysed in 1324 patients. There was no statistically significant difference (p = 0.47) in overall occurrence of blood culture positivity in COVID-19 patients (9.0, 95% CI 6.8–11.1) in comparison to influenza A (11.4, 95% CI 7.9–14.8) and influenza B patients (10.4, 95% CI 7.1–13.7,). After correcting for the high rate of contamination, the occurrence of clinically relevant bacteraemia in COVID-19 patients amounted to 1.0% (95% CI 0.3–1.8), which was statistically significantly lower (p = 0.04) compared to influenza A patients (4.0, 95% CI 1.9–6.1) and influenza B patients (3.0, 95% CI 1.2–4.9). The most frequently identified bacterial isolates in COVID-19 patients were Escherichia coli (n = 2) and Streptococcus pneumoniae (n = 2). The overall 30-day all-cause mortality for COVID-19 patients was 28.3% (95% CI 24.9–31.7), which was statistically significantly higher (p = <.001) when compared to patients with influenza A (7.1, 95% CI 4.3–9.9) and patients with influenza B (6.4, 95% CI 3.8–9.1). Conclusions We report a very low occurrence of community-acquired bacteraemia amongst COVID-19 patients in comparison to influenza patients. These results reinforce current clinical guidelines on antibiotic management in COVID-19, which only advise utilization of antibiotics when a bacterial co-infection is suspected.

scholarly journals Classical Microbiological Diagnostics of Bacteremia: Are the Negative Results Really Negative? What is the Laboratory Result Telling Us About the “Gold Standard”?

2020 ◽  
Vol 8 (3) ◽  
pp. 346
Author(s):  
Tomasz Źródłowski ◽  
Joanna Sobońska ◽  
Dominika Salamon ◽  
Isabel M. McFarlane ◽  
Mirosław Ziętkiewicz ◽  
...  
Keyword(s):  
Blood Culture ◽  
Healthy Volunteers ◽  
Culture Method ◽  
Blood Cultures ◽  
Gram Stain ◽  
Blood Samples ◽  
Negative Results ◽  
Gram Staining ◽  
Study Results

Standard blood cultures require at least 24–120 h to be reported as preliminary positive. The objective of this study was to compare the reliability of Gram staining and fluorescent in-situ hybridization (FISH) for detecting bacteria in otherwise negative blood culture bottles. Ninety-six sets were taken from patients with a diagnosis of sepsis. Six incomplete blood culture sets and eight blood cultures sets demonstrating positive growth were excluded. We performed Gram stain and FISH on 82 sets taken from post-operative septic patients: 82 negative aerobic blood cultures, 82 anaerobic blood cultures, and 82 blood samples, as well as 57 blood samples taken from healthy volunteers. From the eighty-two blood sets analyzed from the septic patients, Gram stain visualized bacteria in 62.2% of blood samples, 35.4% of the negative aerobic bottles, and in 31.7% of the negative anaerobic bottles. Utilizing FISH, we detected bacteria in 75.6%, 56.1%, and 64.6% respectively. Among the blood samples from healthy volunteers, FISH detected bacteria in 64.9%, while Gram stain detected bacteria in only 38.6%. The time needed to obtain the study results using Gram stain was 1 h, for FISH 4 h, and for the culture method, considering the duration of growth, 5 days. Gram stain and FISH allow quick detection of bacteria in the blood taken directly from a patient. Finding phagocytosed bacteria, which were also detected among healthy individuals, confirms the hypothesis that blood microbiome exists.

METHOD FOR OBTAINING BLOOD CULTURE WHILE DIAGNOSING BLOODSTREAM INFECTION

2020 ◽  
Vol 65 (3) ◽  
pp. 185-190
Author(s):  
N. M. Kargaltseva ◽  
V. I. Kocherovets ◽  
A. Yu. Mironov ◽  
O. Yu. Borisova
Keyword(s):  
Blood Culture ◽  
Blood Sample ◽  
Bloodstream Infection ◽  
Blood Volume ◽  
Venous Blood ◽  
Buffy Coat ◽  
Blood Cultures ◽  
Genetic Identification ◽  
Blood Collection ◽  
Urogenital System

Diagnosing of bloodstream infection (BSI) in outpatients is essential. A large blood volume is required to obtain blood culture (CLSI): 2 sets, 40ml of blood for diagnosing in 95% cases of bacteremia. Molecular-genetic methods can not replace blood culture method, but they accelerate the identification of any pathogen. Culturomics gives a combination of different conditions for isolating microorganisms from a sample and along with their genetic identification. We used the patent method for direct inoculation of buffy-coat from 4,5ml of a venous blood sample and MALDI-ToF identification method. In 382 outpatients examined there were received 183 blood cultures (48,0%), more often among women (65,6%) and young people (74,9%). The causative agents of community-acquired bloodstream infection were aerobes (73,4%), anaerobes (24,2%), fungi (2,4%). The gram-positive cocci were prevailing (51,4%) and the gram-negative rods were isolated rather seldom (9,6%). BSI was monomicrobial (66,5%) and polymicrobial (33,5%). Polymicrobial blood cultures had 2, 3, 4 agents in one blood sample (75,4%, 18,8%, 5,8%, respectively). There were also found combinations of different species of aerobes (47,8%), aerobes with anaerobes (42%). BSI caused complications of the primary disease of the respiratory system, urogenital system and in 100% of cases after plastic surgery. A small blood volume is required for buffy-coat inoculation, the direct agar culture reduces the response time to 2 days, so it makes genetic identification possible on the 2nd day from the moment of blood collection.

scholarly journals Comparative study of manual conventional blood cultures versus automated blood culture system in cases of septicemia

2021 ◽  
Vol 8 (4) ◽  
pp. 327-332
Author(s):  
Humera Qudsia Fatima Ansari ◽  
Lubna Saher ◽  
Mustafa Afzal
Keyword(s):  
Blood Culture ◽  
Culture System ◽  
Blood Cultures ◽  
Diffusion Method ◽  
Suspected Case ◽  
Care Hospital ◽  
Susceptibility Pattern ◽  
Gold Standard Method ◽  
Blood Culture System ◽  
Culture Systems

: Blood cultures are a proven gold standard method for the identification of causative agents of bloodstream infections. Identification of causative organism along with antibiotic susceptibility plays a pivotal role in proposing suitable antibiotic therapy. Automated blood culture systems show improved monitoring of blood cultures by reducing the time and by ensuring more accurate results when compared to the conventional blood culture system. To isolate the organism from given blood samples of a suspected case of septicemia and to compare the results of conventional and automated blood culture systems and to study the antimicrobial susceptibility pattern of the pathogens isolated. A prospective study of 6 months period was conducted among 100 subjects attending the Department of Microbiology in a tertiary care hospital. Subjects with symptoms and signs of septicemia were included. 25ml of venous blood was drawn aseptically from the venipuncture site, of which 5ml of blood was inoculated into 50ml of Brain Heart Infusion bottle in conventional blood culture system and 10ml each into aerobic and anaerobic BACTEC PLUS bottle in Automated blood culture system BACTEC FX40. Overall, 48% and 60% of the samples revealed positive growth by the conventional and automated blood culture system BACTEC FX40, respectively. Gram Positive Cocci were 52.08% and Gram Negative Bacilli were 47.91% isolated by conventional blood culture system, whereas automated blood culture system BACTEC FX40 isolated 45% and 55%, respectively. Isolates were detected within 24-48hrs and 12-24 hrs by conventional and automated blood culture systems, respectively. The anti-microbial susceptibility pattern of the pathogens isolated was also recorded by Kirby Bauer disc diffusion method of antimicrobial susceptiblity testing. Automated blood culture systems are a trustworthy substitute to conventional blood culture systems. The automated blood culture systems being more sensitive and rapid in detecting septicemia in subjects acts as an appropriate means for the initial identification and detection of blood pathogens and improved provision of antimicrobial therapeutic options for septic Patients especially in Critical Care and Intensive Care Units where positive culture reporting is crucial.

scholarly journals Evaluation of an Initial Specimen Diversion Device (ISDD) on Rates of Blood Culture Contamination in the Emergency Department

2021 ◽  
Vol 14 ◽  
pp. 73-76
Author(s):  
Blake Buzard ◽  
Patrick Evans ◽  
Todd Schroeder
Keyword(s):  
Emergency Department ◽  
Length Of Stay ◽  
Blood Culture ◽  
Blood Cultures ◽  
Contamination Rate ◽  
Total Hospital Cost ◽  
Initial Specimen ◽  
Significant Difference ◽  
Secondary Outcomes ◽  
The Impact

Introduction: Blood cultures are the gold standard for identifying bloodstream infections. The Clinical and Laboratory Standards Institute recommends a blood culture contamination rate of <3%. Contamination can lead to misdiagnosis, increased length of stay and hospital costs, unnecessary testing and antibiotic use. These reasons led to the development of initial specimen diversion devices (ISDD). The purpose of this study is to evaluate the impact of an initial specimen diversion device on rates of blood culture contamination in the emergency department.  Methods: This was a retrospective, multi-site study including patients who had blood cultures drawn in an emergency department. February 2018 to April 2018, when an ISDD was not utilized, was compared with June 2019 to August 2019, a period where an ISDD was being used. The primary outcome was total blood culture contamination. Secondary outcomes were total hospital cost, hospital and intensive care unit length of stay, vancomycin days of use, vancomycin serum concentrations obtained, and repeat blood cultures obtained.  Results: A statistically significant difference was found in blood culture contamination rates in the Pre-ISDD group vs the ISDD group (7.47% vs 2.59%, p<0.001). None of the secondary endpoints showed a statistically significant difference. Conclusions: Implementation of an ISDD reduces blood culture contamination in a statistically significant manner. However, we were unable to capture any statistically significant differences in the secondary outcomes.

scholarly journals MTT FORMAZAN REPLACED WST-8 AS A BETTER SIMPLE SCREENING METHOD FOR DETECTION OF GLUCOSE-6-PHOSPHATE DEHYDROGENASE DEFICIENCY

2019 ◽  
Vol 7 (6) ◽  
pp. 161
Author(s):  
Indah Tantular
Keyword(s):  
Screening Method ◽  
Residual Activity ◽  
Rapid Screening ◽  
Blood Samples ◽  
Naked Eye ◽  
Rapid Screening Test ◽  
Hydrogen Carrier ◽  
Purple Color ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Simple Screening

We have previously developed the WST-8 method as a simple and rapid screening test for detection of glucose-6-phosphate dehydrogenase (G6PD) deficiency accomplished by the naked eye. However, it was little difficult to distinguish between faint orange colors developed by heterozygous females and pink colors of normal hemolyzed blood, since both have similar tones. To solve this problem, we established a new and simple screening method that utilizes another formazan substrate, MTT (3-(4,5-dimethyl-2- thiazolyl)-2,5-diphenyl-2H tetrazolium bromide) in combination with a hydrogen carrier, 1-methoxy phenazine methosulfate. MTT formazan exhibits a purple color, thus allowing for the ability to easily distinguish the pink colors of hemolyzed blood. However, MTT has been reported to react with hemoglobin non-specifically and to interfere with the interpretation of the color reaction. In our examinations by mixing MTT with hemolyzed blood, we found that the non-specific reaction was very slow, and that the addition of a small amount of blood (5~10 μl) into a reaction mixture (800 μl) did not interfere with the reaction of G6PD activity. In this new MTT method, a strong purple color was generated in normal blood samples at 20~30 min after incubation, which could be distinguished by the naked eye from G6PD-deficient blood samples with less than 50% residual activity. In addition, quantitative measurement using a spectrophotometer was also possible despite the fact that MTT formazan is water-insoluble.

Rapid Detection of Microorganisms in Blood Cultures of Newborn Infants Utilizing an Automated Blood Culture System

PEDIATRICS ◽  
2000 ◽  
Vol 105 (3) ◽  
pp. 523-527 ◽  
Author(s):  
Joseph A. Garcia-Prats ◽  
Timothy R. Cooper ◽  
Virginia F. Schneider ◽  
Charles E. Stager ◽  
Thomas N. Hansen
Keyword(s):  
Blood Culture ◽  
Rapid Detection ◽  
Culture System ◽  
Newborn Infants ◽  
Blood Cultures ◽  
Blood Culture System

P935 Time-to-positivity of aerobic blood cultures by using BacTec 9120 blood culture system

2007 ◽  
Vol 29 ◽  
pp. S244-S245
Author(s):  
St. Fokas ◽  
Sp. Fokas ◽  
G. Altouvas ◽  
M. Tsironi ◽  
S. Kaptanis ◽  
...  
Keyword(s):  
Blood Culture ◽  
Culture System ◽  
Blood Cultures ◽  
Blood Culture System ◽  
Time To Positivity

Obtaining Blood Cultures by Venipuncture versus from Central Lines Impact on Blood Culture Contamination Rates and Potential Effect on Central Line–Associated Bloodstream Infection Reporting

2013 ◽  
Vol 34 (10) ◽  
pp. 1042-1047 ◽  
Author(s):  
John M. Boyce ◽  
Jacqueline Nadeau ◽  
Diane Dumigan ◽  
Debra Miller ◽  
Cindy Dubowsky ◽  
...  
Keyword(s):  
Blood Culture ◽  
Bloodstream Infection ◽  
Hospital Costs ◽  
Cost Savings ◽  
Central Line ◽  
Potential Effect ◽  
Blood Cultures ◽  
Blood Samples ◽  
Central Lines ◽  
Contaminated Blood

Objective.Reduce the frequency of contaminated blood cultures that meet National Healthcare Safety Network definitions for a central line-associated bloodstream infection (CLABSI).Design.An observational study.Setting.A 500-bed university-affiliated hospital.Methods.A new blood culture policy discouraged drawing blood samples from central lines. Phlebotomists were reeducated regarding aseptic technique when obtaining blood samples by venipuncture. The intravenous therapy team was taught how to draw blood samples by venipuncture and served as a backup when phlebotomists were unable to obtain blood samples. A 2-nurse protocol and a special supply kit for obtaining blood samples from catheters were developed. Rates of blood culture contamination were monitored by the microbiology laboratory.Results.The proportion of blood samples obtained for culture from central lines decreased from 10.9% during January–June 2010 to 0.4% during July–December 2012 (P< .001). The proportion of blood cultures that were contaminated decreased from 84 (1.6%) of 5,274 during January–June 2010 to 21 (0.5%) of 4,245 during January–June 2012 (P< .001). Based on estimated excess hospital costs of $3,000 per contaminated blood culture, the reduction in blood culture contaminants yielded an estimated annualized savings of $378,000 in 2012 when compared to 2010. In mid-2010, 3 (30%) of 10 reported CLABSIs were suspected to represent blood culture contamination compared with none of 6 CLABSIs reported from mid-November 2010 through June 2012 (P= 0.25).Conclusions.Multiple interventions resulted in a reduction in blood culture contamination rates and substantial cost savings to the hospital, and they may have reduced the number of reportable CLABSIs.

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