scholarly journals Identification of Gram-negative bacilli directly from positive blood culture vials

2007 ◽  
Vol 56 (4) ◽  
pp. 475-479
Author(s):  
Siew Yong Ng ◽  
Lee Ling Kwang ◽  
Thean Yen Tan
Keyword(s):  
Blood Culture ◽  
Positive Blood Culture ◽  
Clinical Management ◽  
Blood Cultures ◽  
Potential Saving ◽  
Biochemical Tests ◽  
Gram Negative ◽  
Genus Level ◽  
Direct Inoculation ◽  
Genus Identification

The provision of rapid results from positive blood cultures is important for the clinical management of septicaemia. This study tested the accuracy of direct inoculation of biochemical tests from positive blood culture vials for the identification of members of the Enterobacteriaceae and Acinetobacter species. A hundred and eighty-one samples were included in the study, with 25 % subsequently excluded as a result of mixed colonial growth. The study method successfully identified 133 (98 %) isolates from 136 vials to genus level and was technically simple to perform, requiring an additional 3 min for the processing of each positive vial. The results of this study demonstrate that a direct inoculation method provides acceptable genus identification of Gram-negative bacilli in positive blood culture vials, with a potential saving of 24 h compared with traditional methods.

ATG Use Is Associated with Frequent Occurrence of Positive Blood Cultures in Patients in the Early Phase After Hematopoietic Stem Cell Transplantation

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 4564-4564
Author(s):  
Marek Seweryn ◽  
Urszula Jarosz ◽  
Malgorzata Krawczyk-Kulis ◽  
Miroslaw Markiewicz ◽  
Grzegorz Helbig ◽  
...  
Keyword(s):  
Stem Cell ◽  
Hematopoietic Stem Cell Transplantation ◽  
Blood Culture ◽  
Stem Cell Transplantation ◽  
Positive Blood Culture ◽  
Blood Cultures ◽  
Gram Negative Bacteria ◽  
Hematopoietic Stem ◽  
Gram Negative ◽  
Gram Positive Bacteria

Abstract Abstract 4564 Background: Infectious complications remain an important cause of morbidity and mortality in the early phase after hematopoietic stem cell transplantation (HSCT). Aim: The aim of this study was to assess the frequency of positive blood cultures and its potential correlation with different studied parameters in large patient population studied in the first 30 days after HSCT. Material and methods: 431 patients at median age of 47 years (range 18–85) transplanted between 2009–2011 for hematological and non-hematological malignancies were included in our analysis. There were 242 males and 189 females. Results: The indications for autologous and allogeneic HSCT were following: AML – 105 (24%), NHL – 86 (20%), MM – 75 (17,5%), HL – 48 (11%), ALL – 40 (9%), MDS – 17 (4%), AA – 15 (3,5%), CML – 12 (2,8%), PNH – 11 (2,6%), connective tissue diseases – 5 (1,2%), CLL – 3 (0,7%) and other – 14 (3,2%). The following transplant procedures were performed: ABCT – 213 (49%), ABMT – 3 (0,7%), alloBCT – 56 (13%), alloBMT – 21 (5%), URDBCT – 87 (20%), URDBMT – 51 (12%). Pre-transplant ATG and anti-CD52 antibody were used in 142 (33%) and 5 (1.2%) patients, respectively. Amongst 431 transplanted patients, 495 blood cultures were collected; range 0–8 (median 1). Eighty seven blood samples were positive (17,6%). The following pathogens were detected: gram-positive bacteria in 48% (n=42), gram-negative bacteria in 38% (n=33), fungi in 1% (n=1) and both G(+) and G(−) bacteria in 13%(n=11). The gram-positive bacteria included: Staphylococcus epidermidis: 21 (50%), Micrococcus spp: 4 (9%), Enterococcus faecium: 3 (7%), Enterococcus faecalis: 3 (7%), Streptococcus haemolyticus: 3 (7%). The following gram-negative bacteria were found: Enterobacter cloacae: 10 (30%), Escherichia coli: 7 (21%), Pseudomonas aeruginosa: 5 (15%), Klebsiella pneumonia: 5 (15%). Candida albicans was detected only in one case. The use of ATG was associated with higher number of total blood draw and positive blood cultures. No significant correlation was found between the specific pathogen and the use of ATG. Male gender was associated with significantly higher number of blood sampling and with tendency to higher number of positive blood cultures. The type of conditioning regimen, the source of stem cell and the donor origin (auto vs sibling vs unrelated) did not influence the number of positive blood culture. There was tendency to higher number of blood intake, but not positive blood culture in patients transplanted in NR if compared to PR or CR. Conclusions: Positive blood cultures were positive in about 20% of patients after HSCT. Only pre-transplant ATG use was associated with the higher number of positive blood culture. Disclosures: No relevant conflicts of interest to declare.

Processing of Positive Blood Cultures Using a Total Laboratory Automation System: Workflow and Clinical Validation

2019 ◽  
Vol 152 (Supplement_1) ◽  
pp. S31-S32
Author(s):  
Kaitlin Mitchell ◽  
Abby Crozier ◽  
Carey-Ann Burnham ◽  
Melanie Yarbrough
Keyword(s):  
Blood Culture ◽  
Positive Blood Culture ◽  
Culture Broth ◽  
Blood Cultures ◽  
Laboratory Automation ◽  
Clinical Testing ◽  
Gram Negative ◽  
Automated Processing ◽  
Total Laboratory Automation ◽  
Anaerobic Media

Abstract Automated systems for culture-based microbiology are in the early phase of implementation in clinical laboratories. Here, our objective was to evaluate the performance of the BD Kiestra Total Laboratory Automation (TLA) System for inoculation, incubation, and imaging of positive blood culture broth specimens. To optimize parameters for clinical testing, 56 clinical specimens were processed using both TLA and manual standard-of-care (SOC) methods. For TLA processing, 3 mL positive blood culture broth (35 VersaTREK: 19 aerobic, 16 anaerobic; 21 BD BACTEC: 15 aerobic, 6 anaerobic) was transferred to a no-additive vacutainer using a safety adapter and syringe. This aliquot was then placed on TLA for fully automated processing: 10 µL was inoculated to blood, chocolate, and MacConkey agar (Remel) and, for anaerobic bottles only, Brucella blood agar (Hardy Diagnostics). Kiestra cross-streak pattern 5 was optimal for obtaining isolated colonies and was superior to quadrant-streaking methods. Additional media types were added based on Gram stain results of the positive blood specimen: CandiSelect (Bio-Rad) and Sabouraud Dextrose (Remel) were added if yeast were identified, and Colistin Nalidixic Acid agar (Remel) for Gram stains with mixed Gram-positive and Gram-negative morphology. Plates were imaged at 6, 8, 10, 12, 18, 38, and 62 hours. Anaerobic media were placed by the system in a media stacker, incubated off-line, and then imaged on the TLA at 24, 48, and 72 hours. SOC cultures were evaluated after overnight incubation and on days 2 and 3. Organism identification was performed using MALDI-TOF MS (Bruker). Based on our evaluation, optimal parameters for clinical implementation of TLA were identified. Microbial growth was scant at 6 hours of incubation, but by 8 hours, small discrete colonies were observed for most aerobes. Thus, imaging parameters selected for routine clinical testing were 8, 18, and 38 hours for aerobic media and one image taken at 38 hours for anaerobic media. TLA and SOC culture results had 96% agreement (29 Gram positive, 12 Gram negative, 5 mixed, 6 yeast, 1 no growth). Two specimens with a second low-abundance bacterial population were observed on TLA that were not observed with SOC. Reproducibility of TLA was tested by processing 6 positive samples in triplicate and found to be 100%. There was no carryover or contamination noted between specimens processed simultaneously on TLA. To evaluate if implementation of TLA impacted epidemiology of positive blood cultures, we compared the 10 most common organisms recovered pre- and post-TLA implementation (August-November 2017 compared to August-November 2018). We found these organisms were not significantly impacted by TLA processing. In conclusion, automated processing of positive blood cultures improves laboratory workflows and facilitates faster workup at 8 hours of incubation. These results demonstrate that automation is a viable avenue for the processing of positive blood cultures.

scholarly journals 1039. Surveillance Blood Cultures Associated With Decreased Mortality in Gram-Negative Bacteremia

2018 ◽  
Vol 5 (suppl_1) ◽  
pp. S310-S311
Author(s):  
Stacey A Maskarinec ◽  
David Van Duin ◽  
Felicia Ruffin ◽  
Vance G Fowler Jr ◽  
Joshua T Thaden
Keyword(s):  
Blood Culture ◽  
Hospital Mortality ◽  
Positive Blood Culture ◽  
Blood Cultures ◽  
Statistical Testing ◽  
Chi Square ◽  
Gram Negative ◽  
Staphylococcus Aureus Bacteremia ◽  
Gram Negative Bacteremia ◽  
Persistent Bacteremia

Abstract Background Prior studies have suggested that surveillance blood cultures (SBCs) may not be indicated in the setting of Gram-negative bacteremia (GNB). However, it is unclear how particular microbial species influence the need for SBCs in GNB. Methods We conducted a prospective cohort study of inpatients at Duke with Staphylococcus aureus bacteremia (SAB) and GNB from 2002–2015. Patients who died <24 hours from the first positive blood culture were excluded. Patients provided written informed consent. SBCs were defined as a blood culture drawn from 24 hours to 7 days from initial positive blood culture. Persistent bacteremia was defined as a positive SBC with the same organism. Statistical testing included Fishers exact and chi-square tests. Results There were 2856 episodes of bacteremia over the study period (SAB: 1,147 [40%]; GNB: 1,709 [60%]). SBCs were drawn in 87% (1,003/1,147) of SAB patients and 64% (1,097/1,709) of GNB patients. SBC rates varied by GNB species (P < 0.001), being more commonly drawn for those patients with Pseudomonas bacteremia (128/159 [80%]) than those with Escherichia bacteremia (377/592 [62%]). In GNB, acquisition of SBCs, regardless of positivity, was associated with decreased in-hospital mortality (177/1,173 [15%] vs. 109/536 [20%]; P = 0.008). The in-hospital mortality benefit associated with SBCs varied with GNB species, including Pseudomonas (30/128 [23%] vs. 14/31 [45%]; P = 0.02) and Escherichia (33/377 [9%] vs. 37/215 [17%]; P = 0.003). In-hospital mortality in those with SAB was also lower when SBCs were drawn (143/1003 [14%] vs. 46/144 [32%]; P = 0.0001) (figure). In GNB, positive SBCs, relative to negative SBCs, was associated with increased in-hospital mortality (44/217 [20%] vs. 133/956 [14%]; P = 0.02). Persistent bacteremia occurred in 49% (494/1003) of SAB patients and 20% (217/1097) of GNB patients with SBCs. Persistent bacteremia risk differed by GNB species (P = 0.004), and was highest among those with Stenotrophomonas maltophilia (9/19 [47%]) or Serratia (24/76 [31%]). Conclusion Acquisition of SBCs in patients with GNB was associated with decreased mortality, and this was driven in part by species-specific differences. Disclosures D. Van Duin, achaogen: Scientific Advisor, Consulting fee. shionogi: Scientific Advisor, Consulting fee. Allergan: Scientific Advisor, Consulting fee. Astellas: Scientific Advisor, Consulting fee. Neumedicine: Scientific Advisor, Consulting fee. Roche: Scientific Advisor, Consulting fee. T2 Biosystems: Scientific Advisor, Consulting fee. V. G. Fowler Jr., Merck, Cerexa/Actavis, Pfizer, Advanced Liquid Logis, NIH, MedImmune, Basilea, Karius, Contrafect, Regneron, Genentech, Affinergy, Locus, Medical Surface, Inc., Achaogen, Astellas, Arsanis, Bayer, Cubist, Debiopharm, Durata, Grifols, Medicines Co, Novartis: Collaborator, Consultant and Scientific Advisor, Consulting fee, Research grant and Research support.

Impact of rapid diagnostics with antimicrobial stewardship support for children with positive blood cultures: A quasi-experimental study with time trend analysis

2020 ◽  
Vol 41 (8) ◽  
pp. 883-890
Author(s):  
Alison C. Tribble ◽  
Jeffrey S. Gerber ◽  
Warren B. Bilker ◽  
Ebbing Lautenbach
Keyword(s):  
Blood Culture ◽  
Antimicrobial Stewardship ◽  
Positive Blood Culture ◽  
Interrupted Time Series ◽  
Blood Cultures ◽  
Hospitalized Children ◽  
Gram Positive ◽  
Gram Negative ◽  
Definitive Therapy ◽  
Quasi Experimental

AbstractObjective:Evaluate the clinical impact of the implementation of VERIGENE gram-positive blood culture testing (BC-GP) coupled with antimicrobial stewardship result notification for children with positive blood cultures.Design:Quasi-experimental study.Setting:Quaternary children’s hospital.Patients:Hospitalized children aged 0–21 years with positive blood culture events 1 year before and 1 year after implementation of BC-GP testing.Methods:The primary outcome was time to optimal antibiotic therapy for positive blood cultures, defined as receiving definitive therapy without unnecessary antibiotics (pathogens) or no antibiotics (contaminants). Secondary outcomes were time to effective therapy, time to definitive therapy, and time to stopping vancomycin, length of stay, and 30-day mortality. Time-to-therapy outcomes before and after the intervention were compared using Cox regression models and interrupted time series analyses, adjusting for patient characteristics and trends over time. Gram-negative events were included as a nonequivalent dependent variable.Results:We included 264 preintervention events (191 gram-positive, 73 gram-negative) and 257 postintervention events (168 gram-positive, 89 gram-negative). The median age was 2.9 years (interquartile range, 0.3–10.1), and 418 pediatric patients (80.2%) had ≥1 complex chronic condition. For gram-positive isolates, implementation of BC-GP testing was associated with an immediate reduction in time to optimal therapy and time to stopping vancomycin for both analyses. BC-GP testing was associated with decreased time to definitive therapy in interrupted time series analysis but not Cox modeling. No such changes were observed for gram-negative isolates. No changes in time to effective therapy, length of stay, or mortality were associated with BC-GP.Conclusions:The implementation of BC-GP testing coupled with antimicrobial stewardship result notification was associated with decreased time to optimal therapy and time to stopping vancomycin for hospitalized children with gram-positive blood culture isolates.

scholarly journals Diagnostic Study on Identification Method of Enterobacteriaceae Directly from Blood Culture

Sains Medika ◽  
2016 ◽  
Vol 6 (2) ◽  
pp. 43
Author(s):  
V. Rizke Ciptaningtyas ◽  
Rebriarina Hapsari ◽  
Tri Nur Kristina ◽  
Winarto Winarto
Keyword(s):  
Blood Culture ◽  
Reference Method ◽  
Blood Cultures ◽  
Diagnostic Study ◽  
Primary Isolation ◽  
Two Samples ◽  
Direct Inoculation ◽  
Identification Of Bacteria ◽  
Laboratory Time ◽  
Genus Identification

Introduction: The provision of rapid diagnosis results from positive blood cultures is important for clinical management of sepsis. Using conventional method as a reference method in laboratory, time needed for bacterial identification are 24 hours longer because it has to deal with primary isolation step. Objectives: This study investigated the accuracy of direct inoculation technique of bacteria from positive blood culture vials to biochemical test tubes without primary isolation step to identify Enterobacteriaceae, second most common causative agent of sepsis.Methods: The study was conducted at the Microbiology Laboratory Medical Faculty of Diponegoro University. This is a diagnostic study. As the study sample, blood cultures in BACTEC bottles from Dr. Kariadi General Hospital Semarang with bacterial growth in it. Inclusion criteria was Gram-negative rod bacteri, staining results from BACTEC blood culture bottles, and as a exclusion criteria, there are more than one colony found on blood agar and Mac Conkey agar and showed positive result in oxidation test. Identification of bacteria based on biochemical table of Enterobacteriaceae. Data were analyzed with a 2x2 table.Results: Thirty two samples included in this study. Ten samples (31%) were excluded. Twenty one from twenty two (95%) study samples accurately identified to the genus level by direct inoculation method.Conclusion: The results showed that the direct inoculation method provides an acceptable genus identification, with a potential saving of 24 hours compared with conventional methods.

scholarly journals 649. Clinical Implementation of a Rapid Susceptibility Testing Procedure, Directly From a Positive Blood Culture Using the Vitek®2 System on Gram Negative Rods

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S383-S383
Author(s):  
Charma Henry ◽  
Dustin Evans ◽  
Daniel Navas ◽  
Arleen Barker ◽  
Chonnapat Somyos ◽  
...  
Keyword(s):  
Blood Culture ◽  
Positive Blood Culture ◽  
Susceptibility Testing ◽  
Testing Procedure ◽  
Turnaround Time ◽  
National Average ◽  
Major Error ◽  
Clinical Implementation ◽  
Salmonella Spp ◽  
Gram Negative

Abstract Background The national average of identification and susceptibility for organisms isolated from positive blood culture to final susceptibility based on growth on solid media is 48 hours. The goal of this research was to prove that the Vitek®2 (bioMérieux, Inc.) system can provide an accurate and reliable susceptibility result directly from positive blood culture for Gram negative rods and reduce the turnaround time (TAT) from positive blood culture to the final susceptibility. Methods An FDA-modified validation procedure was performed on positive blood cultures directly from the bottle to the VITEK®2 System for susceptibility testing. The protocol tested and validated an aliquot of 50uL of blood directly from the positive bottle into 10 mL of saline (1:200). The solution was vortexed and 3mL were placed in the VITEK®2 test tube. This protocol was intended only for Gram negative rods using the AST-GN70, AST-GN81 & AST-GN801 cards. This protocol followed the CLSI M52 and M100 guidelines. Results 515 organisms from clinical blood culture samples from July 2018 to October 2019 were evaluated. Organisms included, but were not limited to: E. coli, K. pneumoniae, Enterobacter spp., and P. aeruginosa, Proteus spp., Salmonella spp., Acinetobacter spp., and S. maltophilia. There were 5,201 drug/bug combinations. AdventHealth Orlando achieved an essential agreement of 99.32% (n=5,166), minor error 0.74% (n=39) major error 0.02% (n=1) and very major error 0.49% (n=2). A 100% agreement was achieved on detection of ESBL, CRE, and MDR organisms. Conclusion Rapid direct blood culture protocol using the VITEK®2 System and the AST-GN cards is accurate, reliable and can be performed with less than 1 minute hands-on time. The protocol can be implemented in any laboratory at no additional costs or modification where the current VITEK®2 AST-GN panels are in use. This protocol was clinically implemented at AdventHealth Orlando on July 15, 2019. Compared with the national average of 72 hours, the TAT obtained during this study was 23 hours from positive blood culture to final susceptibility, a significant reduction of 25 hours. The authors encourage bioMérieux Inc. to evaluate and explore the opportunity to expand the use of the VITEK®2 system for this application with the appropriate clinical trial. Disclosures All Authors: No reported disclosures

scholarly journals Sepsis in cancer patients residing in Zimbabwe: Spectrum of bacterial and fungal aetiologies and their antimicrobial susceptibility patterns.

2019 ◽  
Author(s):  
FRANK CHINOWAITA ◽  
Wendy Chaka ◽  
Tinashe K Nyazika ◽  
Tendai C Maboreke ◽  
Inam Chitsike ◽  
...  
Keyword(s):  
Blood Culture ◽  
Cancer Patients ◽  
Antimicrobial Susceptibility ◽  
Methicillin Resistance ◽  
Antimicrobial Treatment ◽  
Blood Cultures ◽  
Gram Negative ◽  
E Coli ◽  
Patients With Cancer ◽  
Susceptibility Patterns

Abstract Introduction: Cancer and sepsis comorbidity is a major public health problem in most parts of the world including Zimbabwe. The microbial aetiologies of sepsis and their antibiograms vary with time and locations. Knowledge on local microbial aetiologies of sepsis and their susceptibility patterns is critical in guiding empirical antimicrobial treatment choices. Methods: This was a descriptive cross sectional study which determined the microbial aetiologies of sepsis from blood cultures of paediatric and adult cancer patients obtained between July 2016 and June 2017. The TDR-X120 blood culture system and TDR 300B auto identification machine were used for incubation of blood culture bottles and identification plus antimicrobial susceptibility testing, respectively. Results: A total of 142 participants were enrolled; 50 (35.2%) had positive blood cultures with 56.0% gram positive, 42.0% gram negative bacteria and 2.0% yeast isolates. Most common isolates were Coagulase Negative Staphylococcus (CoNS) (22.0%), Escherichia coli (16.0%), Klebsiella pneumoniae (14.0%), Enterococcus faecalis (14.0%) and Staphylococcus aureus (8.0%) in all cancer patients. These isolates were similar in both haematological and solid cancers. Amikacin and meropenem showed 85.7% and 95.2% activity respectively against all gram negative isolates while vancomycin and linezolid were effective against 96.2% and 100.0% of all gram positive isolates respectively. Ten (66.7%) isolates of E. coli and K. pneumoniae were extended spectrum β-lactamase (ESBL) positive and the same proportion was observed on methicillin resistance among Staphylococcus species. Conclusions: The major microbial aetiologies of sepsis among patients with cancer in Zimbabwe were CoNS, E. coli, K. pneumoniae, E. faecalis and S. aureus. Most isolates were resistant to commonly used empirical antibiotics and there was high level of ESBL and methicillin resistance carriage. A nationwide survey on microbial aetiologies of sepsis and their susceptibility patterns would assist in the guidance of effective sepsis empiric antimicrobial treatment among patients with cancer.

scholarly journals Antimicrobial Resistance Patterns of Bacterial Isolates from Blood Culture among HIV/AIDS Patients at Felege Hiwot Referral Hospital, Northwest Ethiopia

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Mohabaw Jemal ◽  
Teshiwal Deress ◽  
Teshome Belachew ◽  
Yesuf Adem
Keyword(s):  
Antimicrobial Resistance ◽  
Blood Culture ◽  
Agar Plate ◽  
Blood Cultures ◽  
Resistant Bacteria ◽  
Bacterial Isolates ◽  
Aids Patients ◽  
Gram Positive ◽  
Gram Negative ◽  
Hiv Aids

Background. The emergence and spread of antimicrobial resistance in bacteria is recognized as a global public health problem. Bloodstream infection with antimicrobial-resistant bacteria in HIV/AIDS patients makes the problem more challenging. So, regular and periodic diagnosis and use of the appropriate antimicrobial susceptibility pattern determination is the only option for decreasing the prevalence and development of drug-resistant bacteria. Methods. An institution-based cross-sectional study was conducted among 384 HIV/AIDS patients. Sociodemographic data of patients were recorded using structured questionnaires. Blood cultures were collected with BACTEC aerobic blood culture bottles. A pair of samples was collected from each patient aseptically and incubated at 37°. If samples are positive for bacterial agents, they were subcultured to solid media such as blood agar plate, chocolate agar plate, and MacConkey agar plates. Identification was performed using colony characteristics and standard biochemical techniques. The antimicrobial susceptibility test was determined by the Kirby–Bauer disc diffusion method. Data entry and analysis were performed while using SPSS version 20. Descriptive statistics were performed to calculate frequencies. Results. Altogether, 384 patients were included, and 123 blood cultures were positive, so that the yield was thus 32%. About 46 (37.4%) of Gram-negative and 77 (62.6%) of Gram-positive bacterial species were identified. Among Gram-negative bacterial isolates, K. pneumoniae was the leading pathogen, 19 (41.3%), whereas S. aureus, 38 (49.4%), was predominant among Gram-positive isolates. In his study, the majority of Gram-positive isolates showed high level of resistance to penicillin, 72 (95.5%), tetracycline, 55 (71.4%), and cotrimoxazole, 45 (58.4%). About 28 (73.6%) of S. aureus isolates were also methicillin-resistant. Gram-negative bacterial isolates also showed a high resistance to ampicillin (91.3%), tetracycline (91.3%), and gentamicin (47.8%). Overall, about 78% of multidrug resistance was observed. Conclusion. Several pathogens were resistant to greater than five antimicrobial agents, so that proper management of patients with bacteremia is needed, and a careful selection of effective antibiotics should be practiced.

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