scholarly journals The Performance of Direct Disk Diffusion for Community Acquired Bacteremia due to Gram-Negative Bacilli and Its Impact on Physician Treatment Decisions

Author(s):  
Peter Daley ◽  
Adam Comerford ◽  
Jurgienne Umali ◽  
Carla Penney

Background.Direct disk diffusion susceptibility testing provides faster results than standard microtitre susceptibility. The direct result may impact patient outcome in sepsis if it is accurate and if physicians use the information to promptly and appropriately change antibiotic treatment.Objective.To compare the performance of direct disk diffusion with standard susceptibility and to consider physician decisions in response to these early results, for community acquired bacteremia with Gram-negative Bacilli.Methods.Retrospective observational study of all positive blood cultures with Gram-negative Bacilli, collected over one year. Physician antibiotic treatment decisions were assessed by an infectious diseases physician based on information available to the physician at the time of the decision.Results.89 bottles growing Gram-negative Bacilli were included in the analysis. Direct disk diffusion agreement with standard susceptibility varied widely. In 47 cases (52.8%), the physician should have changed to a narrower spectrum but did not, in 18 cases (20.2%), the physician correctly narrowed from appropriate broad coverage, and in 8 cases (9.0%), the empiric therapy was correct.Discussion.Because inoculum is not standardized, direct susceptibility results do not agree with standard susceptibility results for all drugs. Physicians do not act on direct susceptibility results.Conclusion.Direct susceptibility should be discontinued in clinical microbiology laboratories.

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S144-S144
Author(s):  
Azza Elamin ◽  
Faisal Khan ◽  
Ali Abunayla ◽  
Rajasekhar Jagarlamudi ◽  
aditee Dash

Abstract Background As opposed to Staphylococcus. aureus bacteremia, there are no guidelines to recommend repeating blood cultures in Gram-negative bacilli bacteremia (GNB). Several studies have questioned the utility of follow-up blood cultures (FUBCs) in GNB, but the impact of this practice on clinical outcomes is not fully understood. Our aim was to study the practice of obtaining FUBCs in GNB at our institution and to assess it’s impact on clinical outcomes. Methods We conducted a retrospective, single-center study of adult patients, ≥ 18 years of age admitted with GNB between January 2017 and December 2018. We aimed to compare clinical outcomes in those with and without FUBCs. Data collected included demographics, comorbidities, presumed source of bacteremia and need for intensive care unit (ICU) admission. Presence of fever, hypotension /shock and white blood cell (WBC) count on the day of FUBC was recorded. The primary objective was to compare 30-day mortality between the two groups. Secondary objectives were to compare differences in 30-day readmission rate, hospital length of stay (LOS) and duration of antibiotic treatment. Mean and standard deviation were used for continuous variables, frequency and proportion were used for categorical variables. P-value < 0.05 was defined as statistically significant. Results 482 patients were included, and of these, 321 (67%) had FUBCs. 96% of FUBCs were negative and 2.8% had persistent bacteremia. There was no significant difference in 30-day mortality between those with and without FUBCs (2.9% and 2.7% respectively), or in 30-day readmission rate (21.4% and 23.4% respectively). In patients with FUBCs compared to those without FUBCs, hospital LOS was longer (7 days vs 5 days, P < 0.001), and mean duration of antibiotic treatment was longer (14 days vs 11 days, P < 0.001). A higher number of patients with FUBCs needed ICU care compared to those without FUBCs (41.4% and 25.5% respectively, P < 0.001) Microbiology of index blood culture in those with and without FUBCs Outcomes in those with and without FUBCs FUBCs characteristics Conclusion Obtaining FUBCs in GNB had no impact on 30-day mortality or 30-day readmission rate. It was associated with longer LOS and antibiotic duration. Our findings suggest that FUBCs in GNB are low yield and may not be recommended in all patients. Prospective studies are needed to further examine the utility of this practice in GNB. Disclosures All Authors: No reported disclosures


2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S726-S726
Author(s):  
Heather L Cox ◽  
April E Attai ◽  
Allison M Stilwell ◽  
Kasi B Vegesana ◽  
Frankie Brewster ◽  
...  

Abstract Background Rapid diagnostic testing paired with ASP intervention optimizes therapy and improves outcomes but few data guide ASP response in the absence of organism identification (ID). We describe the microbiology for organisms unidentified by Accelerate Pheno™ Gram-negative platform (AXDX) in order to inform ASP-provider team communication (PTC). Methods Consecutive, non-duplicate inpatient blood cultures with Gram-negative bacilli (GNB) following AXDX implementation at a single university hospital between April 2018 and March 2019 were included. Standard of care (SOC) ID and susceptibility followed AXDX. Clinical Microbiology emailed AXDX results to the ASP in real time; results were released into the EMR paired with telephone PTC or withheld after ASP review. Bloodstream Infections (BSIs) and patient outcomes for organisms labeled no/indeterminate ID by the AXDX were characterized. Results AXDX was performed on 351 blood cultures. Among 52 (15%) labeled no/indeterminate ID, SOC methods revealed: Enterobacteriaceae (40%; 9 monomicrobial with AXDX targets), anaerobes (21%), non-lactose fermenters (NLFs) other than Pseudomonas aeruginosa (21%), and fastidious GNB (10%). Frequent organisms without AXDX targets included: Raoultella planticola (4); Bacteroides fragilis, Cupriavidus spp., Haemophilus spp., Prevotella spp., Providencia spp., non-aeruginosa Pseudomonas spp., Salmonella spp. (3 each); Pasteurella multocida, Stenotrophomonas maltophilia (2 each). BSI sources were most commonly intra-abdominal (21%), central line-associated (17%), or unknown (17%). CLABSIs were associated with immune suppression and/or substance abuse in all but 1 case. BSIs without active empiric therapy included: NDM-producing Providencia stuartii SSSI; OXA-48-producing R. planticola intraabdominal infection (IAI); Pandoraea spp. CLABSI after liver transplant; enteric fever; B. fragilis, Leptotrichia wadei, and S. maltophilia, each of unknown source. In-hospital mortality occurred in 4 of these cases. Conclusion When AXDX yields no/indeterminate ID, ASP chart review for possible anaerobic/IAI, unique environmental exposures, and travel history may assist in guiding empiric therapy. GNB with AXDX targets are not excluded. Disclosures All authors: No reported disclosures.


Author(s):  
Zineb Lachhab ◽  
Mohammed Frikh ◽  
Adil Maleb ◽  
Jalal Kasouati ◽  
Nouafal Doghmi ◽  
...  

Objectives.We conducted a one-year observational study from December 2012 to November 2013 to describe the epidemiology of bacteraemia in intensive care units (ICU) of Mohammed V Military Teaching Hospital of Rabat (Morocco).Methods.The study consisted of monitoring all blood cultures coming from intensive care units and studying the bacteriological profile of positive blood cultures as well as their clinical significance.Results.During this period, a total of 46 episodes of bacteraemia occurred, which corresponds to a rate of 15,4/1000 patients. The rate of nosocomial infections was 97% versus 3% for community infections. The most common source of bacteraemia was the lungs in 33%, but no source was identified in 52% of the episodes. Gram negative organisms were isolated in 83,6% of the cases withAcinetobacter baumanniibeing the most frequent. Antibiotic resistance was very high with 42,5% of extended-spectrum beta-lactamases (ESBLs) in Enterobacteriaceae and 100% of carbapenemase inAcinetobacter baumannii. The antibiotherapy introduced in the first 24 hours was adequate in 72% of the cases.Conclusions.Bloodstream infections in ICU occur most often in patients over 55 years, with hypertension and diabetes. The bacteria involved are mainly Gram negative bacteria multiresistant to antibiotics. Early administration of antibiotics significantly reduces patients mortality.


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