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 ◽  
...  

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.

2005 ◽  
Vol 26 (8) ◽  
pp. 697-702 ◽  
Author(s):  
Benoît Favre ◽  
Stéphane Hugonnet ◽  
Luci Correa ◽  
Hugo Sax ◽  
Peter Rohner ◽  
...  

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.


2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S353-S354
Author(s):  
Sarah Perreault ◽  
Molly Schiffer ◽  
Jennifer Zhao ◽  
Dayna McManus ◽  
Francine Foss ◽  
...  

Abstract Background Treatment of GvHD with steroids increases the risk of infection in HSCT patients due to additive immunosuppression and may delay the diagnosis of infection due to lack of symptoms. Outpatient surveillance blood cultures in HSCT with GvHD being treated with HD steroids has demonstrated a blood culture positivity rate of 3.5%. Currently, the utility of surveillance cultures in patients receiving LD steroid therapy is unknown. Our practice includes weekly outpatient surveillance cultures for all GvHD patients treated with steroids regardless of the dose. The primary endpoint of this study was to assess the incidence of positive surveillance blood cultures in GvHD patients receiving HD or LD steroids. Secondary endpoints included number of patients treated, hospitalization, 30 day mortality due to infection, and organisms isolated. Methods This was a single-center, retrospective review of GvHD patients at Yale New Haven Hospital between January 2013 and May 2019. Patients were excluded if: lack of signs or symptoms of GvHD, treatment with steroids for any indication other than GvHD, and active GvHD without central line. Cultures from patients receiving antibiotics for concurrent infection were also excluded. Results A total of 71 patients met criteria with 901 blood cultures. On HD, eight patients (14%) had 12 positive cultures (4%), and on LD, 16 patients (25%) had 22 positive cultures (4%) (p=0.15). Treatment occurred in six patients (75%) with four (24%) requiring hospitalization on HD, and 12 patients (75%) with 10 (83%) requiring hospitalization on LD (p=0.45). The median duration of steroid therapy was 93 and 236 days with a median dose of steroids of 1mg/kg/day and 0.15mg/kg/day, respectively. The number of positive cultures/1000 steroid days was 1.2 on HD and 0.5 on LD (RR 2.2). 30 day mortality was only noted in one patient (8%) on LD. The most common organism in both groups was Coagulase-negative staphylococci with all six cultures on HD classified as contaminants and 6/10 cultures requiring treatment on LD. Conclusion Although the relative risk of positive surveillance blood cultures in HD patients compared to LD was twofold higher, there were clinically significant infections identified in the LD group. Disclosures All Authors: No reported disclosures


PEDIATRICS ◽  
1990 ◽  
Vol 86 (2) ◽  
pp. 157-162
Author(s):  
Joseph W. St Geme ◽  
Louis M. Bell ◽  
Stephen Baumgart ◽  
Carl T. D'Angio ◽  
Mary Catherine Harris

Coagulase-negative staphylococci represent the most common cause of serious nosocomial infection in many intensive care nurseries. However, these organisms are also common blood culture contaminants. To determine the value of quantitative blood cultures in distinguishing sepsis from culture contamination, we reviewed records of all infants in our nurseries who had peripheral blood isolates of coagulase-negative staphylococci during a 3-year period. Twenty-three episodes of sepsis were identified in 21 infants, and 10 infants had blood culture contamination. Colony counts from the initial peripheral blood culture were significantly different for the two study groups (P < .001). In 9 of 23 episodes of sepsis, the initial peripheral blood culture grew >100 colony-forming units (cfu) per mL. In the other 14 episodes, the initial culture yielded ≤50 cfu/mL. All 10 infants with culture contamination had colony counts of <50 cfu/mL, and in 9 the initial peripheral blood culture grew <20 cfu/mL. Infants with sepsis, including those with colony counts of ≤50 cfu/mL, were significantly more likely to have a central catheter or an abnormal hematologic value or both (P < .05). Infants who lacked these clinical features were more likely to have contamination. We conclude that quantitative blood cultures in conjunction with specific clinical information may distinguish sepsis from culture contamination with coagluase-negative staphylococci in young infants. In addition, low colony-count growth should not be ignored as contamination in this high-risk population.


2004 ◽  
Vol 132 (5) ◽  
pp. 921-925 ◽  
Author(s):  
M. MÜLLER-PREMRU ◽  
P. ČERNELČ

Catheter-related bloodstream infection (CRBSI) caused by coagulase-negative staphylococci (CNS) is common in haematological patients with febrile neutropenia. As the clinical signs of CRBSI are usually scarce and it is difficult to differentiate from blood culture contamination, we tried to confirm CRBSI by molecular typing of CNS isolated from paired blood cultures (one from a peripheral vein and another from the central venous catheter hub). Blood cultures were positive in 59 (36%) out of 163 patients. CNS were isolated in 24 (40%) patients; in 14 from paired blood cultures (28 isolates) and in 10 from a single blood culture. CNS from paired blood cultures were identified as Staphylococcus epidermidis. Antimicrobial susceptibility was determined and bacteria were typed by pulsed-field gel electrophoresis (PFGE) of bacterial genomic DNA. In 13 patients, the antibiotic susceptibility of isolates was identical. The PFGE patterns from paired blood cultures were identical or closely related in 10 patients, thus confirming the presence of CRBSI. In the remaining four patients they were unrelated, and suggested a mixed infection or contamination. Since CNS isolates from three patients had identical PFGE patterns, they were probably nosocomially spread amongst them.


1984 ◽  
Vol 5 (3) ◽  
pp. 142-143 ◽  
Author(s):  
D.J. Flournoy

Coagulase-negative staphylococci (CONS) have only recently gained notoriety as pathogens. Several reports have established their pathogenicity in bacterial endocarditis, prosthetic heart valve endocarditis, intraventricular shunts for treatment of hydrocephalus and intravenous catheters. One difficult decision for physicians is determining whether a particular CONS isolate is pathogenic or contaminant. The differentiation of pathogenic and contaminant CONS has recently been noted, but further studies are needed to aid in this differentiation. Data on antimicrobial susceptibilities of positive blood culture isolates were recently compiled at this institution. This report compares antimicrobial susceptibilities of pathogenic and contaminant CONS and Staphylococcus aureus blood culture isolates from 1961-1981 at this institution.


2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 9535-9535
Author(s):  
B. Kanathezhath ◽  
J. Feusner

9535 Background: Infections continue to be a major cause of morbidity and mortality in pediatric oncology patients (pts) with febrile neutropenia (FN). The proportion of such pts who have bacteremia documented after 72 hours (hrs) of broad-spectrum antibiotics, in the absence of local or systemic signs of infection, has not been previously reported. Methods: We conducted a retrospective analysis of all FN oncology pts admitted to our hospital during the period of August 1999 to October 2006. Blood cultures (BCs) from pts who were persistently febrile more than 3 days after initiation of empiric broad-spectrum antibiotics (ceftazidime and tobramycin) were analyzed. Medical records of pts with positive late blood cultures (LBCs) after 72 hrs were reviewed for onset of new signs and symptoms of infection. Hematopoietic stem cell transplant and HIV pts were excluded. Results: Ninety-seven episodes of persistent fever occurred in 71 FN pts. The total number of positive BCs in the first 72 hours was 24 (33.8%). Three (4.2%) of the persistently febrile pts had positive LBC. Of these 3 pts, one had preceding new signs and symptoms. Another had a probable contaminant (only 1 positive BC for coagulase-negative staphylococcus). Only one pt (1.4%) had positive LBC without any new local or systemic signs of infection. The observed frequency of positive LBC was 4.2% for pts and 0.8% (3/391) for total cultures obtained after 72 hours. There were no changes made in the antibiotic regimen of pts with positive LBC and none of them suffered from sepsis related mortality. Conclusions: This is the first report of late blood culture results in FN pediatric oncology pts. The practice of obtaining daily blood culture in such pts who are stable after 72 hrs of broad- spectrum antibiotics has a low yield (<5%), and even lower (<2%) if pts with new signs or symptoms at the LBC are excluded. This observation, if confirmed by larger studies from other centers, could lead to a more efficient, risk based strategy for following these pts. No significant financial relationships to disclose.


2021 ◽  
Vol 8 (Supplement_1) ◽  
pp. S157-S157
Author(s):  
Sujeet Govindan ◽  
Luke Strnad

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


2020 ◽  
Author(s):  
Takahiro Matsuo ◽  
Kuniyoshi Hayashi ◽  
Aki Sakurai ◽  
Masumi Suzuki Shimizu ◽  
Masaya Morimoto ◽  
...  

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.


2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S775-S775
Author(s):  
G Taylor A George ◽  
Kurt Stevenson ◽  
Joan-Miquel Balada-Llasat ◽  
Kelci E Coe

Abstract Background Burkholderia cepacia complex (Burkholderia cenocepacia and Burkholderia multivorans) (BCC) are uncommon, yet serious often drug-resistant pathogens of immunocompromised patients, especially in lung transplants; pre-operative infection/colonization is seen as a contraindication to transplant. Optimal treatment for these difficult infections is not known. We examined impact of single vs. combination therapy on patient outcomes. Methods All cases of BCC positive pulmonary or blood cultures at The Ohio State University Wexner Medical Center between January 1, 2012 and June 30, 2018 were analyzed. No cystic fibrosis patients were included. All combinations thereof were evaluated. The primary outcomes were 30 all-cause mortality and 30-day infection-related mortality. Secondary outcomes included sterilization of cultures, isolation of a non-susceptible isolate within 30 days of therapy, hospital and intensive care unit (ICU) length of stay, and adverse drug effects (ADE) of therapy including: hyperkalemia, acute kidney injury (AKI), transaminitis, and QTc prolongation. Results There were 90 unique patients who grew BCC (22 patients with 92 positive blood cultures; 54 patients with 87 positive pulmonary cultures). Four patients had mixed pulmonary and blood cultures. Ten patients died prior to having treatment for their cultures and were not evaluated. Overall, there were 85 evaluable infection events. Overall 30-day all-cause mortality was 20/85 (23.5%); mortality in blood culture monotherapy 3/14 (21.4%); combination therapy 3/18 (16.7%) (P = 1.00). Mortality in pulmonary culture monotherapy was 6/32 (18.75%); combination 10/30 (33.3%) (P = 0.19). Among blood cultures monotherapy was associated with 8 ADE while combination therapy was 11 (P = 0.82). In pulmonary patients, monotherapy had 16 ADE while combination had 23 (P = 0.03). Conclusion Overall mortality trends improved with combination therapy in blood culture patients and with monotherapy patients in pulmonary cultures. These findings are influenced by the limited number of patients available, and the medical co-morbidities of these patients. In lung patients there were significantly fewer ADE associated with monotherapy as opposed to combination therapy. Disclosures All authors: No reported disclosures.


2012 ◽  
Vol 46 (11) ◽  
pp. 1484-1490 ◽  
Author(s):  
Jordan R Wong ◽  
Karri A Bauer ◽  
Julie E Mangino ◽  
Debra A Goff

BACKGROUND: No studies exist regarding the value of pharmacist interventions using rapid identification of coagulase-negative staphylococci (CoNS) by rapid polymerase chain reaction (rPCR) from blood cultures. OBJECTIVE: To evaluate the impact of interventions by infectious diseases pharmacists (ID PharmDs) on blood cultures positive for CoNS using rPCR and assess the duration of antistaphylococcal antibiotic therapy, hospital length of stay (LOS), and related costs. METHODS: A quasi-experimental, pre- and postintervention study of patients with positive blood cultures for CoNS, identified using rPCR, was conducted. Patients were included if there was a blood culture for CoNS from January 1, 2011, to March 31, 2011 (preintervention), or October 1, 2011, to January 18, 2012 (post-intervention). Exclusion criteria included age younger than 18 years or 89 years or older, neutropenia, incomplete records, and duplicate or mixed blood cultures. The setting was a 1200-bed academic medical center. The ID PharmD intervened on blood cultures identified in the postintervention group as CoNS after notification from the microbiology laboratory. The pre- and postintervention groups were compared to analyze the effect of the intervention. The primary outcome was time to discontinuation of antistaphylococcal antibiotics by the pharmacist intervention in patients with a positive blood culture for CoNS that was determined to be a contaminant. RESULTS: We analyzed 53 patients (31 preintervention, 22 postintervention) with CoNS blood culture contaminants. In the postintervention group, antistaphylococcal antibiotics were discontinued 32.0 hours sooner from time of rPCR result (median 57.7 vs 25.7 hours; p = 0.005), total antibiotic exposure decreased 43.5 hours (97.6 vs 54.1 hours; p = 0.011), infection-related LOS decreased 4.5 days (10 vs 5.5 days; p = 0.018), and infection-related costs decreased $8338 ($28,973 vs $20,635; p = 0.144). The pharmacist initiated vancomycin in 7 (21.9%) patients with CoNS bloodstream infections. CONCLUSIONS: Timely interventions by ID PharmDs using rPCR are required to impact the outcomes of patients with positive blood cultures for CoNS.


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