Nosocomial Bacteremia Clinical Significance of a Single Blood Culture Positive for Coagulase-Negative Staphylococci

2005 ◽  
Vol 26 (8) ◽  
pp. 697-702 ◽  
Author(s):  
Benoît Favre ◽  
Stéphane Hugonnet ◽  
Luci Correa ◽  
Hugo Sax ◽  
Peter Rohner ◽  
...  
Keyword(s):  
Blood Culture ◽  
Clinical Significance ◽  
Positive Blood Culture ◽  
Blood Cultures ◽  
University Teaching ◽  
Coagulase Negative Staphylococci ◽  
Nosocomial Bacteremia ◽  
Single Positive ◽  
Clinically Significant ◽  
Culture Positive

AbstractObjectives:To describe the epidemiology of nosocomial coagulase-negative staphylococci (CoNS) bacteremia and to evaluate the clinical significance of a single blood culture positive for CoNS.Design:A 3-year retrospective cohort study based on data prospectively collected through hospital-wide surveillance. Bacteremia was defined according to CDC criteria, except that a single blood culture growing CoNS was not systematically considered as a contaminant. All clinically significant blood cultures positive for CoNS nosocomial bacteremia were considered for analysis.Setting:A large university teaching hospital in Geneva, Switzerland.Results:A total of 2,660 positive blood cultures were identified. Of these, 1,108 (41.7%) were nosocomial; CoNS were recovered from 411 nosocomial episodes (37.1%). Two hundred thirty-four episodes of CoNS bacteremia in the presence of signs of sepsis were considered clinically relevant and analyzed. Crude mortality and associated mortality were 24.4% and 12.8%, respectively. Associated mortality was similar among patients with one positive blood culture and those with two or more (16.2% vs 10.8%, respectively;P= .3). Mortality rates after bacteremia for patients with a single positive blood culture and for those with two or more were 15.3% and 7.0%, respectively, at day 14 (RR, 2.2; CI%, 0.87-5.46) and 20.8% and 11.3%, respectively, at day 28 (RR, 1.9; CI95, 0.9-3.8). On multivariate analysis, only age and a rapidly fatal disease were independently associated with death.Conclusion:CoNS bacteremia harbor a significant mortality and a single positive blood culture in the presence of signs of sepsis should be considered as clinically relevant.

scholarly journals Clinical Significance of Staphylococcus aureus in a Single Positive Blood Culture Bottle

2021 ◽  
Author(s):  
John Raymond Go ◽  
Douglas Challener ◽  
Cristina Corsini Campioli ◽  
M Rizwan Sohail ◽  
Raj Palraj ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Infective Endocarditis ◽  
Blood Culture ◽  
Clinical Significance ◽  
Positive Blood Culture ◽  
Blood Culture Bottle ◽  
Hospital Length Of Stay ◽  
Culture Bottle ◽  
Single Positive ◽  
Clinically Significant

Abstract Clinical significance of a single positive blood culture bottle (SPBCB) with Staphylococcus aureus is unclear. We aimed to assess the significance of a SPBCB by looking at the associated outcomes. We performed a retrospective, multicenter study of patients with a SPBCB with S. aureus using data collected from both electronic health records and the clinical microbiology laboratory. Overall, 534 patients with S. aureus bacteremia were identified and 118 (22.1%) had a SPBCB. Among cases with a SPBCB, 106 (89.8%) were classified as clinically significant while 12 (10.2%) were considered contaminated or of unclear significance. A majority (92.4%) of patients received antibiotic therapy but patients with clinically significant bacteremia were treated with longer courses (25.9 vs 5.7 days, P<0.001). Significant differences in both frequency of echocardiography (65.1% vs 84.6%, P<0.001), and infective endocarditis diagnosis (3.8% vs 14.2%, P=0.002) were seen in those with a single positive blood culture bottle compared to those with multiple positive bottles. A longer hospital length of stay, and higher 90-day, 6-month, and 1-year mortality rates were seen in patients with multiple positive blood culture bottles. A SPBCB with S. aureus was common among our patients. While this syndrome has a more favorable prognosis as compared to those with multiple positive blood cultures, clinicians should remain concerned as it portends a risk of infective endocarditis and mortality.

scholarly journals 81. Reducing Unnecessary Blood Cultures Through Diagnostic Stewardship

2021 ◽  
Vol 8 (Supplement_1) ◽  
pp. S157-S157
Author(s):  
Sujeet Govindan ◽  
Luke Strnad
Keyword(s):  
Blood Culture ◽  
Positive Blood Culture ◽  
Cost Savings ◽  
Bloodstream Infections ◽  
Central Line ◽  
Blood Cultures ◽  
Coagulase Negative Staphylococci ◽  
Candida Sp ◽  
Daily Frequency ◽  
Oregon Health

Abstract Background At our institution, we learned the frequency of blood cultures was sometimes being changed from “Once” to “Daily” without a defined number of days. We hypothesized this led to unnecessary blood cultures being performed. Methods Over a 3 month period from 12/6/2019-3/6/2020, we retrospectively evaluated the charts of patients who had a blood culture frequency changed to “Daily”. We evaluated if there was an initial positive blood culture within 48 hours of the “Daily” order being placed and the number of positive, negative, or “contaminant” sets of cultures drawn with the order. Contaminant blood cultures were defined as a contaminant species, present only once in the repeat cultures, and not present in initial positive cultures. Results 95 unique orders were placed with 406 sets of cultures drawn from 89 adults. ~20% of the time (17 orders) the order was placed without an initial positive blood culture. This led to 62 sets of cultures being drawn, only 1 of which came back positive. 78/95 orders had an initial positive blood culture. The most common initial organisms were Staphylococcus aureus (SA) (38), Candida sp (10), Enterobacterales sp (10), and coagulase negative staphylococci (7). 43/78 (55%) orders with an initial positive set had positive repeat cultures. SA (26) and Candida sp (8) were most common to have positive repeats. Central line associated bloodstream infections (CLABSI) were found in 5 of the orders and contaminant species were found in 4 of the orders. 54% of the patients who had a “Daily” order placed did not have positive repeat cultures. The majority of the cultures were drawn from Surgical (40 orders) and Medical (35 orders) services. Assuming that SA and Candida sp require 48 hours of negative blood cultures to document clearance and other species require 24 hours, it was estimated that 51% of the cultures drawn using the "Daily" frequency were unnecessary. Cost savings over a year of removing the "Daily" frequency would be ~&14,000. Data from "Daily" blood culture orders drawn at Oregon Health & Science University from 12/6/2019-3/6/2020 Conclusion Unnecessary blood cultures are drawn when the frequency of blood cultures is changed to "Daily". Repeat blood cultures had the greatest utility in bloodstream infections due to SA or Candida sp, and with CLABSI where the line is still in place. These results led to a stewardship intervention to change blood culture ordering at our institution. Disclosures All Authors: No reported disclosures

scholarly journals “A Four-Leaf Clover” Sign for Rapid Identification of Coagulase-Negative Staphylococci by Gram Staining From Positive Blood Culture: A Cross-Sectional Study

2020 ◽  
Author(s):  
Takahiro Matsuo ◽  
Kuniyoshi Hayashi ◽  
Aki Sakurai ◽  
Masumi Suzuki Shimizu ◽  
Masaya Morimoto ◽  
...  
Keyword(s):  
Logistic Regression ◽  
Regression Analysis ◽  
Blood Culture ◽  
Positive Predictive Value ◽  
Positive Blood Culture ◽  
Predictive Value ◽  
Blood Cultures ◽  
Coagulase Negative Staphylococci ◽  
Gram Staining ◽  
Sensitivity Specificity

Abstract Background: Coagulase-negative staphylococci (CoNS) are one of the most common contaminant microorganisms isolated from blood cultures. Few studies exploring the use of Gram staining to distinguish between Staphylococcus aureus (SA) and CoNS have been reported. Here, this study aimed to explore whether morphological features of Gram staining could identify SA or CoNS.Methods: This study was conducted at St. Luke’s International Hospital from November 2016 to September 2017. The positive blood cultures for which the Gram staining showed gram-positive cocci (GPC) in clusters were included in our study. The direct smear of Gram staining obtained from positive blood culture bottles were examined within 24 hours of positivity. We have identified and characterized the following two signs: “four-leaf clover (FLC)” if 4 GPC gathered like a planar four-leaf clover and “grapes” if the GPC gathered like grapes in a three-dimensional form. The number of fields with FLC and grapes signs in 10 fields per slide with ×1,000 power was counted, and the results in a total of 20 fields with ×1,000 power were combined. We performed a logistic regression analysis to assess whether these signs could serve as factors distinguishing between SA and CoNS. The predictive ability of these signs was evaluated based on the sensitivity, specificity, positive predictive value, and negative predictive value for CoNS via receiver operating curve analysis.Results: In total, 106 blood cultures for which Gram staining showed GPC in clusters were examined; 46 (43%) were SA, and 60 (57%) were CoNS samples. The result of multivariate logistic regression analysis showed that the FLC sign was a statistically significant marker of CoNS with an odds ratio of 1.31 (95 % confidential interval (CI): 1.07–1.61, p<0.05). In aerobic bottles, sensitivity, specificity, positive predictive value, and negative predictive value for CoNS were 0.67, 0.91, 0.92, and 0.65, respectively, and the value of area under the curve was 0.79 (95% CI: 0.67–0.91).Conclusions: To our knowledge, this is the first study to show that the FLC could be a rapid and useful indicator to identify CoNS in aerobic bottles. Thus, the presence of FLC sings could help clinicians to suspect the possibility of CoNS before the final identification by cultures.

Determining the Significance of Coagulase-Negative Staphylococci Isolated From Blood Cultures at a Community Hospital A Role for Species and Strain Identification

2000 ◽  
Vol 21 (3) ◽  
pp. 213-217 ◽  
Author(s):  
Soon-Duck Kim ◽  
L. Clifford McDonald ◽  
William R. Jarvis ◽  
Sigrid K. McAllister ◽  
Robert Jerris ◽  
...  
Keyword(s):  
Blood Culture ◽  
Species Identification ◽  
Community Hospital ◽  
Signs And Symptoms ◽  
Blood Cultures ◽  
Strain Identification ◽  
Coagulase Negative Staphylococci ◽  
Number Of Patients ◽  
Single Positive ◽  
Laboratory Survey

AbstractObjectives:To determine the degree to which species identification or strain relatedness assessment of successive blood culture isolates of coagulase-negative staphylococci (CNS) may improve the clinical diagnosis of bloodstream infection (BSI).Setting:400-bed community hospital.Design:Prospective laboratory survey during which all CNS blood culture isolates obtained between mid-August 1996 and mid-February 1997 (study period) were saved and later identified to the species level; selected isolates were genotyped using pulsed-field gel electrophoresis at the Centers for Disease Control and Prevention (CDC). Retrospective review of medical records of 37 patients with multiple cultures positive for CNS.Results:During the study period, 171 patients had blood cultures positive for CNS; 130 had single positive cultures and 41 had ≥2 positive cultures. Of these 41, 23 (62%) were from patients with signs and symptoms of BSI according to CDC surveillance definitions. Species identification and strain clonality of CNS isolates from patients with ≥2 positives revealed 3 (13%) of the 23 patients did not have a consistent CNS species, and another 3 (13%) did not have a consistent genotype in the ≥2 positive cultures, suggesting that CNS from these patients probably were contaminants. Thus, species identification and strain clonality assessment reduced by 27% the number of patients with BSI diagnosed based on the presence of symptoms and ≥2 positive blood cultures.Conclusions:Routine species identification and selected strain genotyping of CNS may reduce the misinterpretation of probable contaminants among patients with ≥2 positive blood cultures.

scholarly journals 298. Multicenter retrospective cohort study of the clinical significance of Staphylococcus lugdunensis isolated from a single blood culture set

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S147-S148
Author(s):  
Naomi Hauser ◽  
Justin Kim ◽  
Paul Luethy ◽  
Sarah Schmalzle ◽  
Jacqueline Bork
Keyword(s):  
Blood Culture ◽  
Clinical Significance ◽  
Positive Blood Culture ◽  
Positive Culture ◽  
Central Line ◽  
Blood Cultures ◽  
Adult Patients ◽  
Coagulase Negative Staphylococcus ◽  
Staphylococcus Lugdunensis ◽  
Clinical Criteria

Abstract Background Staphylococcus lugdunensis is a coagulase negative Staphylococcus (CoNS) species with the potential to cause aggressive infection. Guidance surrounding S. lugdunensis bacteremia (SLB) is lacking, especially in the case of a single positive set of blood cultures. Methods We performed a multicenter, retrospective observational cohort review of adult patients with SLB from at least one blood culture set within the University of Maryland Medical System from November 2015-November 2019. Objectives were to (1) describe baseline characteristics, (2) compare available criteria for evaluating clinical significance, and (3) evaluate the clinical outcomes among patients with SLB in 1 vs ≥2 positive blood culture sets. Descriptive statistics with Chi-squared and Mann-Whitney U tests were carried out. Results There were 5,548 CoNS-positive blood culture sets, 49 (0.88%) with S. lugdunensis comprising 36 adult patients (24 with 1 positive set and 12 with ≥2 positive sets). Patients with ≥2 positive sets were more likely to be on hemodialysis (HD) (p=0.029) and to have an HD catheter present (p=0.10) (Table 1). Thirty-five of the 36 patients fulfilled at least one of the following: systemic inflammatory response syndrome (SIRS), Souvenir criteria, or clinical criteria (infectious focus on imaging and/or second positive culture site) (Table 2). Twenty-eight (78%) patients were treated with antimicrobial therapy and/or central line removal. SIRS criteria were met more often among patients with 1 positive set (p=0.05). Patients with ≥2 positive sets were more often treated with antibiotics for longer than 2 weeks (p=0.02). The mean time of positive cultures to discharge was 11 days and was longer for patients with only one set of positive blood cultures (13 vs. 6 days), although this difference was not statistically significant (p=0.29) (Table 3). Conclusion SLB was rare and occurred more frequently as a single set of positive blood cultures. Though limited by sample size, this study found similar patient characteristics, clinical significance and outcomes between patients with one set and those with ≥2 sets of blood cultures positive for S. lugdunensis. Given the potential severity of SLB, it seems prudent to treat S. lugdunensis in a single blood culture, but larger studies are needed. Disclosures All Authors: No reported disclosures

scholarly journals Investigation of Antimicrobial Susceptibilities Among Bacteria Isolated from Blood Cultures in Hospitalized Patients, Tehran, Iran

2021 ◽  
Vol 16 (2) ◽  
Author(s):  
Shadi Aghamohammad ◽  
Maryam Nouri ◽  
Fatemeh Ashrafian ◽  
Mohtaram Sadat Kashi ◽  
Mehrdad Gholami ◽  
...  
Keyword(s):  
Blood Culture ◽  
Positive Blood Culture ◽  
Antimicrobial Agents ◽  
Clinical Laboratory ◽  
Blood Cultures ◽  
Multi Drug Resistance ◽  
National Committee ◽  
Coagulase Negative Staphylococci ◽  
Gram Positive ◽  
Cross Sectional

Background: Bacteremia is the status, which is detected via a positive blood culture test with no contamination. Centers for Disease Control and Prevention (CDC) indicates that direct medical procedures and total costs are significantly high. Antibiotic resistance can play a major role in the costs, which are related to the long duration of treatment. Objectives: The aim of this study was to investigate the rate and profiles of antimicrobial susceptibility of blood culture isolates from Tehran, Iran. Methods: In the current cross-sectional study, a total of 5,000 blood culture samples were collected from patients hospitalized in the Loghman General Hospital, Tehran, Iran, with positive blood culture results from 2012 to 2013. Susceptibility to antimicrobial agents was analyzed using National Committee for Clinical Laboratory Standards guidelines. Results: Coagulase-negative staphylococci (38.8%), Staphylococcus aureus (20.5%), Acinetobacter (11.9%), and Escherichia coli (11.7%) were the most frequent bacteria isolated from the blood cultures, collectively accounting for > 80% of the isolates. Of isolated microorganisms, 63.75% and 36.24% belonged to Gram-positive and Gram-negative bacteria, respectively. Moreover, 88% of the isolates were MRSA (oxacillin-/methicillin-resistant), and 7% were VRE (vancomycin-resistant). Conclusions: The most frequent isolated organisms were Gram-positive bacteria, and the rate of MDR (multi-drug resistance) was high. The results of the current study obviously indicate the misuse of antibiotic in society. National surveillance studies in Iran will be useful for clinicians to choose the right empirical treatment and will help control and prevent infections caused by resistant organisms.

scholarly journals 6. Staphylococcus aureus in a Single Blood Culture Bottle: Should We be Concerned?

2021 ◽  
Vol 8 (Supplement_1) ◽  
pp. S5-S6
Author(s):  
John Raymond U Go ◽  
Douglas Challener ◽  
Cristina G Corsini Campioli ◽  
Muhammad R Sohail ◽  
Raj Palraj ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Blood Culture ◽  
Clinical Significance ◽  
Positive Blood Culture ◽  
Laboratory Finding ◽  
Clinical Importance ◽  
Blood Culture Bottle ◽  
Clinical Microbiology Laboratory ◽  
Culture Bottle ◽  
Clinically Significant

Abstract Background Staphylococcus aureus bacteremia (SAB) is common and is characterized by high rates of morbidity and mortality. The clinical importance of a single positive blood culture bottle (SPBCB), however, is poorly defined despite it being a frequent laboratory finding. We therefore examined patients with SPBCB to determine its clinical significance and to understand the rationale of current practice. Methods We performed a retrospective, multicenter study of patients with a SPBCB for S. aureus in initial cultures from January 2019 to December 2019 using data collected from both electronic health records and the clinical microbiology laboratory. Results Overall, 534 patients with SAB were identified, and 118 (22.1%) had a SPBCB. Among SPBCB cases, 106 (89.3%) were classified as clinically significant while 12 were considered contaminated or of unclear clinical significance. Baseline characteristics were similar between the groups (Table 1). A majority (92.4%) received antibiotic therapy, but patients with clinically significant bacteremia were treated with a longer antibiotic course (25.9 vs 5.7 days, p&lt; 0.001). Outcomes between those with SPBCB (contaminant vs clinically significant) were similar (Table 2). Of note, while there was no difference in use of echocardiography based on PREDICT criteria between the clinically significant SPBCB vs. the multiple positive blood culture bottles (MPBC) cohorts (Table 3), significant differences were seen in both frequency of echocardiography (65.1% vs. 84.6%, P&lt; 0.001) and IE diagnosis (3.8% vs. 14.2%, P=0.002) for patients in the SPBCB vs. MPBC groups, respectively. In addition, those with MPBC had higher 90-day, 6-month and 1-year mortality rates. Conclusion SPBCB was documented in almost one-quarter of SAB cases and should trigger a thorough investigation as its associated mortality was high and complications, including IE, occurred. Although some SPBCB cases may represent contamination, antibiotic treatment of SPBCB was commonplace. Patients with clinically significant SPBCB were less likely to undergo echocardiography and had a reduced prevalence of an IE diagnosis as compared to those with MPBC. Patients with SPBCB may have a more favorable long-term prognosis as compared to that in patients with MPBC. Disclosures Muhammad R. Sohail, MD, Medtronic (Consultant)Philips (Consultant) Larry M. Baddour, MD, Boston Scientific (Individual(s) Involved: Self): Consultant; Botanix Pharmaceuticals (Individual(s) Involved: Self): Consultant; Roivant Sciences (Individual(s) Involved: Self): Consultant

scholarly journals Incidence of Bacteremia at the Time of ICU Admission and its Impact on Outcome

2020 ◽  
Vol 5 (1) ◽  
pp. 61-63
Author(s):  
Jose B Cherayath ◽  
Jitin George
Keyword(s):  
Blood Culture ◽  
Positive Blood Culture ◽  
Tertiary Hospital ◽  
Blood Cultures ◽  
Suspected Sepsis ◽  
Suspected Infection ◽  
Icu Admission ◽  
Admission Time ◽  
Clinically Significant ◽  
Hospital Wards

Background: For patients admitted in ICU, if they are suspected with infection, at admission time, blood culture is taken. Aim: This study aimed to evaluate the bacteraemia incidence at the ICU admission time, and assess its impact on the outcome.Subjects and Methods:This is a retrospective study which was conducted in a tertiary hospital. At time of admission, data from all the ICU admissions with suspected sepsis were analysed over a period of July 2016 to June 2018. The positive blood culture group (Group A) consisted of patients with clinically significant BSI.Results:600 patients were selected in the study. 250 patients out of 600 patients (42%) were on antibiotics. 380 patients out of 600 patients (63%) were direct ICU admission from casualty, 70 patients from hospital wards (11%), 45 patients from other ICU’s in the hospital (8%) and 105 patients from other hospitals (18%). Blood cultures were positive only in 70 patients (11.6%) with significant BSI. ICU mortality was significantly higher in positive blood culture group (i.e. 30/70), when compared with negative blood culture group (i.e. 68/530). Mortality was higher in patients with pseudomonas aeruginosa (75%) though it was not statistically significant.Conclusion:In the ICU, only in minority of patients with suspected infection, blood cultures may be positive. Even though the patients are administered with antibiotics, prognosis of the patients with positive blood culture is worse.

scholarly journals An estimate for the source of coagulase-negative staphylococci in blood cultures

1987 ◽  
Vol 99 (2) ◽  
pp. 333-341 ◽  
Author(s):  
M. J. Haverkorn ◽  
M. J. Staal
Keyword(s):  
Blood Culture ◽  
Positive Blood Culture ◽  
Heart Surgery ◽  
Open Heart Surgery ◽  
Culture Technique ◽  
Blood Cultures ◽  
The Other ◽  
Open Heart ◽  
Coagulase Negative Staphylococci ◽  
Two Populations

SUMMARYAn estimate for the source of coagulase-negative staphylococci in blood cultures is presented and its use illustrated in two populations. The method estimates the probability that a positive blood culture is positive due to contamination and the probability of it being positive due to bacteraemia. The effect of changes in efficiency of the blood culture technique on these estimates is demonstrated. One of the illustrative populations consists of 537 sample pairs from 273 patients, taken after open-heart surgery in 1978–80. The other consists of 500 consecutive sample pairs taken in one of two hospitals in 1983–4.

scholarly journals An Assessment of the Anaerobic Vial of Paired NR 6A and NR 7N Bactec Blood Cultures

1994 ◽  
Vol 5 (1) ◽  
pp. 37-40 ◽  
Author(s):  
Kevin R Forward ◽  
Elizabeth Kerr ◽  
Maurice Dalton
Keyword(s):  
Blood Culture ◽  
Patient Care ◽  
Teaching Hospital ◽  
Retrospective Review ◽  
Tertiary Care ◽  
Blood Cultures ◽  
Clinical Laboratories ◽  
Obligate Anaerobic ◽  
Clinically Significant ◽  
Culture Positive

Objective: To determine the number of obligate anaerobes recovered in anaerobic blood culture vials and to determine if their recovery had a significant impact on patient care.Design: Retrospective review.Setting: Tertiary care teaching hospital.Main Results: Six thousand nine hundred and five pairs of Bactec blood cultures were submitted (each set consisted of one 6A and one 7N vial). Of these, 690 sets were culture-positive in at least one of the vials (10% of pairs). Both vials were positive in 406 (58.8%). The aerobic vial alone was positive in 176 (25.5%) and the anaerobic vial alone was positive in 107 (15.5%). Of these, most were facultative anaerobes; however, 20 blood culture sets from 18 patients were positive for obligate anaerobes. In five of the 18, the isolate was judged to be a contaminant. In 11 of 13 patients, the clinically significant obligate anaerobic bacteremia might have been predicted on clinical grounds, and in eight patients, empirical antianaerobic antibiotics had been started before the results of blood cultures were known.Conclusions: Clinical laboratories should carefully examine the use of the routine anaerobic blood culture and consider its replacement with larger volume aerobic blood culture vials.

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