scholarly journals Environmental Drivers of Bacillus-Positive Blood Cultures in a Cancer Hospital, Sapporo, Japan

Author(s):  
Takahiro Fujita ◽  
Hiroshi Nishiura

The Bacillus species is a well-documented causative pathogen of nosocomial bloodstream infection. The present study aimed to identify climatological variables that are associated with Bacillus-positive blood culture in Sapporo, Japan. All cases with Bacillus-positive blood cultures from January 2011 to December 2016 were retrospectively analysed. Climatological data from 2011 to 2016, including daily mean temperature and absolute humidity, were retrieved from the Japan Meteorological Agency. Employing a hazard-based statistical model to describe the non-homogeneous counting process in which temperature and absolute humidity act as explanatory variables, we computed all possible models with variable lengths of time lag. Akaike Information Criterion was computed to identify the best fitted model. High wavelet power at 12 months was identified for the period from 2013 onwards, which coincided with the time period in which sampling multiple sets of blood culture has been recommended. The temperature-only model with a lag of six days yielded a high sensitivity value (72.1%) and appeared to be the optimal model to predict Bacillus-positive blood culture with the highest area under the receiver operating characteristic curve value. Temperature was identified as a climatological driver of Bacillus-positive blood culture. Our statistical modelling exercise offers an important message for infection control practices to improve awareness among healthcare workers of the identified association and mechanically controlled in-room temperature.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kei Yamamoto ◽  
Kazuhisa Mezaki ◽  
Norio Ohmagari

AbstractCoagulase-negative staphylococci (CoNS) are the most frequent contaminating bacteria; therefore, we aimed to investigate an indicator of CoNS to predict the increase in blood culture contamination rate (ConR). We performed a retrospective study of selected patients, who underwent blood culture testing. Contamination was defined as the presence of either one of two or more sets of skin-resident bacteria, except for cases with a low likelihood of contamination based on clinical aspects. We calculated the monthly ConR [(total number of contaminated cases per month)/(total number of blood culture sets collected per month) × 100] and analysed the ConR prediction ability using the following four indicators: the number of CoNS-positive sets of blood cultures, cases with at least one CoNS-positive blood culture set, cases with only one CoNS-positive blood culture set, and cases of contamination by CoNS. Cases with CoNS-positive blood cultures correlated with ConR (r = 0.85). Although the area under the receiver operating characteristic curve for the number of cases with ConR ≥ 2.5 differed significantly from that of the number of cases contaminated by CoNS, the negative predictive value was high, reaching up to 95.5% (95% confidential interval 87.3–99.1). The number of CoNS-positive cases could help predict an increase in ConR ≥ 2.5.


1984 ◽  
Vol 5 (2) ◽  
pp. 71-74 ◽  
Author(s):  
Inge Gurevich ◽  
Patricia Tafuro ◽  
Sharon P. Krystofiak ◽  
Robert D. Kalter ◽  
Burke A. Cunha

AbstractDuring a ten-month period from September 1981 to July 1982 three episodes of pseudobacteremia due to Bacillus species occurred at this 550-bed institution. The first involved eight isolates, the second 11, and the third seven isolates of the organism, all with the same antibiogram.The patients involved did not exhibit clinical signs of septicemia, and in only one case was more than one specimen per patient positive when multiple blood samples were obtained. Occasional blood cultures of Bacillus species identified in between clusters revealed a different antibiogram.Extensive epidemiologic investigation of patient locations, phlebotomists, and time of cultures yielded no common source. Components involved in the transport and processing of blood cultures, including the radiometric blood culture processor, were also sampled but without recovery of the organism. After the last episode, a layer of dust was noted inside the machine, and culture of this dust grew Bacillus spp. with the same antibiogram as those found in the blood cultures. The filter from an air conditioning unit in close proximity to the machine grew several species of Bacillus.It is presumed that Bacillus spores in the dust were introduced into the blood culture bottles following the heat sterilization of the gas sampling (inoculation/removal) needles.Modification of the cover of the machine was undertaken to prevent access of dust bearing microbes to the inside of the machine. In addition, maintenance now includes regular disinfection/cleaning of the “floor” of the machine, and more frequent changes of the air conditioner filter.


2019 ◽  
Vol 152 (Supplement_1) ◽  
pp. S133-S133
Author(s):  
Kemin Xu ◽  
Sarwat Gilani ◽  
Hank Wang ◽  
John Fallon

Abstract Objectives Blood culture is one of the most important tests performed in clinical microbiology laboratories. However, blood culture contamination remains a problematic cause of diagnostic errors for laboratory diagnosis and patient management. This aim of this study was to determine blood culture contamination rates and tendency at Westchester Medical Center (WMC), a tertiary teaching hospital in suburban New York City. Methods All blood culture tests at WMC received from January 2017 to December 2018, as well as some historical data from 2007 to 2014, were retrospectively retrieved. Blood culture contamination rates were determined according to the laboratory’s predefined criteria. Results From 2007 to 2014, a total of 209,750 blood cultures were performed with an average contamination rate of 1.6% (ranging from 0.4% to 3.5% monthly). The total numbers of blood cultures performed in 2017 and 2018 were 27,863 and 28,047, respectively. The overall positive rate of blood culture was 6.8% in 2017 and 7.6% in 2018. The contamination rate of blood culture was 0.6% in 2017 and 0.9% in 2018 with very few variations among different months of the year, which was significantly lower than that of the national benchmark (~2.5%) on blood culture contamination. The majority of contaminants were Staphylococcus epidermidis, accounting for 87% of source contamination, followed by Corynebacterium species (5.5%), Bacillus species and Micrococcus species (3.5% each), and Propionibacterium species (0.5%). Conclusion Adherence to current guideline on appropriate blood collection techniques and monthly monitoring and timely feedback to phlebotomists should be continued to keep a low contamination rate for blood culture, which is not only from the perspective of individual patient care but also from the standpoint of hospital epidemiology and public health.


Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 4564-4564
Author(s):  
Marek Seweryn ◽  
Urszula Jarosz ◽  
Malgorzata Krawczyk-Kulis ◽  
Miroslaw Markiewicz ◽  
Grzegorz Helbig ◽  
...  

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.


2021 ◽  
Author(s):  
Hanyu Zhang ◽  
Zhaoqing Lu ◽  
Guoxing Wang ◽  
Di Wu ◽  
Xu Ge ◽  
...  

Abstract Background: Presepsin is currently a promising biomarker for the early diagnosis and prognosis of acute bacterial infection. Acute cholangitis is caused by bacterial infection and has high morbidity and mortality. The study engaged to assess the grading and prognostic value of presepsin in patients with acute cholangitis. Methods: This study enrolled patients with acute cholangitis in the emergency department from May 1, 2019 to December 20, 2020. The patients were evaluated for severity by the 2018 Tokyo Guidelines for Acute Cholangitis. Patients’ baseline features and routine clinical data were collected. On admission, presepsin, procalcitonin (PCT) and systemic inflammatory response syndrome (SIRS) and sequential organ failure assessment (SOFA) scores were determined; and blood cultures were performed. IBM SPSS software (version 22.0) was used. The comparation of values was performed by Pearson chi-square test or Fisher's exact test or Mann-Whitney U test. The area under the receiver operating characteristic curve (AUC), multivariate logistic regression, and correlation analysis were used to analyze this importance of determining the presepsin levels on admission for acute cholangitis. Results: In total, 330 patients, including 109, 101, and 120 patients classified as having mild, moderate, and severe cholangitis, respectively, were examined. The AUCs of presepsin were 0.713 in predicting severe acute cholangitis, better than those of white blood cell (WBC 0.411), C-reactive protein (CRP 0.615), PCT 0.608, and total bilirubin (T-Bil 0.441) (P<0.05). The AUC of presepsin in predicting 28-day mortality was higher than that of WBC, CRP, PCT, and T-Bil. The presepsin level in the positive blood culture group was higher than that in the negative blood culture group (P=0.000). The P values for correlations of presepsin with SIRS and SOFA scores were 0.002 and 0.000, respectively. Conclusions: Presepsin levels on admission were correlated with SIRS and SOFA scores. Presepsin may predict positive blood culture and 28-day mortality in patients with acute cholangitis, and it is superior to WBC, CRP, PCT, and T-Bil in the risk stratification and prognostic assessment of severe cholangitis. Trial registration: Ethical code of this study is 2018-P2-063-01 and acquired on May, 22, 2018.


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.


2021 ◽  
Vol 26 (8) ◽  
pp. 802-808
Author(s):  
Lauren M. Puckett ◽  
Poonam Rajkotia ◽  
Lisa Coppola ◽  
Lori Baumgartner ◽  
Amity L. Roberts ◽  
...  

OBJECTIVE Identification of organisms directly from positive blood culture by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has the potential for improved clinical outcomes through earlier organism identification and shorter time to appropriate clinical intervention. The uses of this technology in pediatric patients and its impact in this patient population have not been well described. METHODS Direct from positive blood culture organism identification via MALDI-TOF was implemented in September 2019. A quality improvement project was performed to assess its impact on admissions for contaminant blood cultures and time to effective and optimal antimicrobials and clinical decision-making. A pre- and post-implementation retrospective review for consecutive September through February time periods, was conducted on patients with positive monomicrobial blood cultures. Statistics were evaluated using Mann-Whitney U and χ2 tests. RESULTS One hundred nineteen patients with 131 unique blood cultures (65 in pre- and 66 in post-implementation) were identified. Time to identification was shorter, median 35.4 hours (IQR, 22.7–54.3) versus 42.3 hours (IQR, 36.5–49) in post- and pre-groups, respectively (p = 0.02). Patients were less likely to be admitted for a contaminated blood culture in the post-implementation, 26% versus 11% in the pre-implementation (p = 0.03) group. In patients treated for bacteremia, there was a shorter time to optimal therapy from Gram stain reporting in the post-implementation (median 42.7 hours [IQR, 27.2–72]) versus pre-implementation (median 60.8 hours [IQR, 42.9–80.6]) (p = 0.03). CONCLUSIONS Direct from positive blood culture identification by MALDI-TOF decreased time to effective and optimal antimicrobials and decreased unnecessary admission in pediatric patients for contaminated blood cultures.


2007 ◽  
Vol 56 (4) ◽  
pp. 475-479
Author(s):  
Siew Yong Ng ◽  
Lee Ling Kwang ◽  
Thean Yen Tan

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.


2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S739-S739
Author(s):  
Vanisha Patel ◽  
Jose Amadeo A Ferrolino ◽  
Randall Hayden ◽  
Randall Hayden ◽  
Aditya H Gaur

Abstract Background Febrile neutropenia (FN) secondary to bacteremia is a treatable complication of chemotherapy that increases mortality if not promptly recognized and managed. Methods The sensitivity of blood cultures collected in pediatric oncology patients with FN was assessed and stratified based on the day of FN episode, culture media type, and the source of blood culture draw at a single US center between 2013 and 2018. Paired aerobic and lytic media bottles were inoculated with each culture draw using a weight-based volume of blood; anaerobic cultures were included with initial cultures starting in September of 2015. Results In a retrospective analysis of 10,596 patients, a total of 3,039 episodes of FN were identified. Of the FN episodes, 17.7% had at least one positive blood culture; 84.5%, 1.3%, 0.9% and 13.3% of positive cultures were collected on day 0, day 1, day 2 and ≥ day 3 of a febrile episode. Among the positive day 0 cultures, the median time to detection of an organism was 14.1 hours. Host characteristics of blood culture-positive FN episodes are summarized in Table 1. Bacteremia was identified in 537 FN cases; 18.1%, 11.9% and 2.6% of cultures were positive in only aerobic, lytic or anaerobic media cultures, respectively. The most commonly isolated organisms were Escherichia coli, coagulase-negative Staphylococcus, viridans group streptococcus, Klebsiella pneumoniae and Pseudomonas aeruginosa. Fifteen percent of infectious episodes with a positive blood culture were polymicrobial. Conclusion In summary, the study findings have important clinical implications such as emphasizing the value of day 0 cultures and highlighting the importance of routinely collecting blood cultures in more than one media type. Despite an optimized blood culture approach, less than a fifth of FN episodes had a blood culture-based diagnosis. Disclosures Randall Hayden, MD, Abbott Molecular: Advisory Board; Quidel: Advisory Board; Roche Diagnostics: Advisory Board.


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