scholarly journals Value of Time to Positivity of Blood Culture in Children with Bloodstream Infections

2019 ◽  
Vol 2019 ◽  
pp. 1-6 ◽  
Author(s):  
Fen Pan ◽  
Wantong Zhao ◽  
Hong Zhang
Keyword(s):  
Bacterial Species ◽  
Bloodstream Infections ◽  
Blood Cultures ◽  
Drug Resistant ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Microbiological Characteristics ◽  
The Mean ◽  
The Relationship

Objective. This study was to investigate the microbiological characteristics and the relationship between the time to positivity (TTP) of blood cultures and different bacterial species and to assess the clinical value of TTP in children with bloodstream infections (BSIs). Methods. The TTP of all the blood cultures from children with suspected BSIs was retrospectively collected in 2016. The microbiological characteristics and the relationship between the TTP of blood cultures and different bacterial species were also analyzed. Results. A total of 808 strains were isolated from 15835 blood cultures collected, and 145 (17.9%) were Gram-negative, 636 (78.7%) were Gram-positive, and 27 (3.3%) were fungi. The bacteria were divided into definite pathogens (174), possible pathogens (592), fungi (27), and contaminants (15). The average TTP of all positive blood cultures was 30.97 and ranged from 3.23 h to 92.73 h. The TTP of Gram-negative strains was significantly shorter than that of Gram-positive strains (P<0.001) and fungi (P = 0.032). The mean TTP for E. coli (15.60 h) was shortest within the group of Gram-negative isolates, and the mean TTP for Streptococcus (17.34 h) within the group of Gram-positive isolates. Significant difference of the TTP was detected in methicillin-resistant vs methicillin-susceptible S. aureus, extended-spectrum beta-lactamases (ESBLs) positive vs negative Enterobacteriaceae, and extensive drug-resistant and non-XDR A. baumannii. The median TTP in patients with BSI was significantly shorter than in those without it (P<0.001). ROC curve analysis indicated that the TTP cutoff value of CoNS, S. aureus, E. coli, and K. pneumoniae was 22.72 h, 19.6 h, 18.58 h, and 16.43 h, respectively, with most sensitive and specific predictor of BSIs. Conclusions. Our data acknowledged that TTP is a valuable index for the early prognosis of BSIs. TTP not only provides additional utility as a general predictor of bacteria with smear result but also provides the implication of drug-resistant organisms.

scholarly journals Removal efficiency of Gram-positive and Gram-negative bacteria using a natural coagulant during coagulation, flocculation, and sedimentation processes

2019 ◽  
Vol 80 (9) ◽  
pp. 1787-1795 ◽  
Author(s):  
Shazwana Sha'arani ◽  
Siti Noor Fitriah Azizan ◽  
Fazrena Nadia Md Akhir ◽  
Muhamad Ali Muhammad Yuzir ◽  
Nor'azizi Othman ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Food Poisoning ◽  
Bloodstream Infections ◽  
Gram Negative Bacteria ◽  
Membrane Composition ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Jar Test ◽  
Sedimentation Processes

Abstract Staphylococcus sp. as Gram-positive and Escherichia coli as Gram-negative are bacterial pathogens and can cause primary bloodstream infections and food poisoning. Coagulation, flocculation, and sedimentation processes could be a reliable treatment for bacterial removal because suspended, colloidal, and soluble particles can be removed. Chemical coagulants, such as alum, are commonly used. However, these chemical coagulants are not environmentally friendly. This present study evaluated the effectiveness of coagulation, flocculation, and sedimentation processes for removing Staphylococcus sp. and E. coli using diatomite with standard jar test equipment at different pH values. Staphylococcus sp. demonstrated 85.61% and 77.23% significant removal in diatomite and alum, respectively, at pH 5. At pH 7, the removal efficiency decreased to 79.41% and 64.13% for Staphylococcus sp. and E. coli, respectively. At pH 9, there was a decrease in Staphylococcus sp. after adding diatomite or alum compared with that of E. coli. The different removal efficiencies of the Gram-positive and Gram-negative bacteria could be owing to the membrane composition and different structures in the bacteria. This study indicates that diatomite has higher efficiency in removing bacteria at pH 5 and can be considered as a potential coagulant to replace alum for removing bacteria by the coagulation process.

scholarly journals PSIX-20 Antibacterial activity of an essential oil combination against several common enteropathogens in swine production

2020 ◽  
Vol 98 (Supplement_3) ◽  
pp. 184-184
Author(s):  
Bernat Canal ◽  
Luis Mesas ◽  
Cinta Sol ◽  
Monica Puyalto ◽  
Ana Carvajal ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Synergistic Effects ◽  
Bacterial Species ◽  
Active Principle ◽  
Swine Production ◽  
Gram Positive ◽  
Minimum Concentration ◽  
Gram Negative ◽  
E Coli ◽  
Broth Microdilution Method

Abstract Essential oils (EOs) have different mechanisms, most of them targeting the bacterial wall. This fact can explain differences in the effectivity of EOs between Gram-positive and Gram-negative bacteria. Therefore, combining certain EOs can broaden their individual spectrum of efficacy due to potential synergistic effects. This trial aimed to test the in vitro antibacterial activity of an EO combination (oregano and clove oils) against a collection of relevant bacterial pathogens in swine production. The Gram-negative bacterial species chosen were Salmonella enterica ssp. enterica, Escherichia coli and Brachyspira hyodysenteriae and the Gram-positive bacterial species were Clostridium perfringens and Streptococcus suis. In addition, Lactobacillus fermentum was included to compare the susceptibility between this beneficial intestinal bacteria and the pathogens tested. The broth microdilution method at pH 6 and the subculturing from wells without bacterial growth were used to determine the minimum concentration of active principle necessary to inhibit (MIC) or kill (MBC) the 50% and 90% (MIC50/90/MBC50/90) of the population of every bacteria. The results showed that the lowest MIC50/90 were obtained for B. hyodysenteriae (37.5/75 ppm) while for S. enterica ssp. enterica (150/300 ppm), C. perfringens (150/150 ppm), E. coli (300/300 ppm) and S. suis (150/300 ppm) results were similar. Regarding the MBC50/90; B. hyodysenteriae (18.8/75 ppm) was the most susceptible pathogen, again, compared to S. enterica ssp. enterica (300/300 ppm), C. perfringens (150/150 ppm), E. coli (300/300 ppm) and S. suis (150/300 ppm). In contrast, the highest bacteriostatic/bactericidal concentrations were obtained against L. fermentum (MIC50/90 600/1,200 ppm and MBC50/90 600/2,400 ppm). These results suggest that the bacterial category (Gram-positive or Gram-negative) did not have an influence on the MIC and MBC. It can also be concluded that B. hyodysenteriae is the most susceptible enteropathogen to this EO blend. However, the in vivo effect of this combination of EOs must be further studied.

scholarly journals Trends of Bloodstream Infections in a University Greek Hospital during a Three-Year Period: Incidence of Multidrug-Resistant Bacteria and Seasonality in Gram-negative Predominance

2017 ◽  
Vol 66 (2) ◽  
pp. 171-180 ◽  
Author(s):  
Fevronia Kolonitsiou ◽  
Matthaios Papadimitriou-Olivgeris ◽  
Anastasia Spiliopoulou ◽  
Vasiliki Stamouli ◽  
Vasileios Papakostas ◽  
...  
Keyword(s):  
Bloodstream Infections ◽  
Multidrug Resistant ◽  
Blood Cultures ◽  
Diffusion Method ◽  
Resistant Bacteria ◽  
Gram Negative Bacteria ◽  
Multidrug Resistant Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Carbapenem Resistant

The aim of the study was to assess the epidemiology, the incidence of multidrug-resistant bacteria and bloodstream infections’ (BSIs) seasonality in a university hospital. This retrospective study was carried out in the University General Hospital of Patras, Greece, during 2011–13 y. Blood cultures from patients with clinical presentation suggestive of bloodstream infection were performed by the BacT/ALERT System. Isolates were identified by Vitek 2 Advanced Expert System. Antibiotic susceptibility testing was performed by the disk diffusion method and E-test. Resistance genes (mecA in staphylococci; vanA/vanB/vanC in enterococci; blaKPC/blaVIM/blaNDM in Klebsiella spp.) were detected by PCR. In total, 4607 (9.7%) blood cultures were positive from 47451 sets sent to Department of Microbiology, representing 1732 BSIs. Gram-negative bacteria (52.3%) were the most commonly isolated, followed by Gram-positive (39.5%), fungi (6.6%) and anaerobes bacteria (1.8%). The highest contamination rate was observed among Gram-positive bacteria (42.3%). Among 330 CNS and 150 Staphylococcus aureus, 281 (85.2%) and 60 (40.0%) were mecA-positive, respectively. From 113 enterococci, eight were vanA, two vanB and two vanC-positives. Of the total 207 carbapenem-resistant Klebsiella pneumoniae (73.4%), 202 carried blaKPC, four blaKPC and blaVIM and one blaVIM. A significant increase in monthly BSIs’ incidence was shown (R2: 0.449), which may be attributed to a rise of Gram-positive BSIs (R2: 0.337). Gram-positive BSIs were less frequent in spring (P < 0.001), summer (P < 0.001), and autumn (P < 0.001), as compared to winter months, while Gram-negative bacteria (P < 0.001) and fungi (P < 0.001) were more frequent in summer months. BSIs due to methicillin resistant S. aureus and carbapenem-resistant Gram-negative bacteria increased during the study period. The increasing incidence of BSIs can be attributed to an increase of Gram-positive BSI incidence, even though Gram-negative bacteria remained the predominant ones. Seasonality may play a role in the predominance of Gram-negative’s BSI.

scholarly journals A comparative study of bloodstream infections in acute myeloid leukemia according to different phases of treatment: Can we predict the organism?

2017 ◽  
Vol 06 (03) ◽  
pp. 132-133
Author(s):  
Preetam Kalaskar ◽  
Asha Anand ◽  
Harsha Panchal ◽  
Apurva Patel ◽  
Sonia Parikh ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Blood Culture ◽  
Myeloid Leukemia ◽  
Bloodstream Infections ◽  
Blood Cultures ◽  
Consolidation Therapy ◽  
Gram Positive ◽  
Gram Negative ◽  
Culture Positive ◽  
Acute Myeloid

Abstract Introduction: The treatment of acute myeloid leukemia (AML) consists of induction therapy with anthracyclines and cytarabine followed by two to four cycles of consolidation therapy with high-dose cytarabine after achieving remission. There have been very few studies comparing infections during induction and consolidation. We have analyzed blood cultures of patients with AML during episodes of fever occurring during induction and consolidation, for comparing the bloodstream infections in both the phases. Materials and Methods: Blood cultures of patients during febrile episodes were collected from central venous catheters and peripheral blood, both during induction and consolidation therapy of AML. Results: The study population included 52 AML patients. During induction, there were 52 episodes of fever and 25 (48%) blood cultures were positive, 15 of these blood cultures reported Gram-negative organisms, 9 reported Gram-positive organisms and 1 as yeast. During consolidation, 47 episodes of fever were recorded and blood cultures were positive in 12, of which 7 were Gram-negative, 5 were Gram-positive. Conclusion: The incidence of blood culture positive infections during therapy of AML at our center was higher. The predominant organism isolated was Gram-negative both during induction and consolidation. The incidence of blood culture positive infections had decreased by 50% during consolidation.

scholarly journals 194. Description of Positive Blood Culture Results not Identified by Verigene Informs Empiric Antibiotic Selection

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S116-S117
Author(s):  
Connor Deri ◽  
Whitney Nesbitt ◽  
George Nelson ◽  
Jessica Keefe
Keyword(s):  
Antibiotic Therapy ◽  
Resistance Mechanism ◽  
Bloodstream Infections ◽  
Blood Cultures ◽  
Aerobic Bacteria ◽  
Gram Positive ◽  
Antibiotic Selection ◽  
Gram Negative ◽  
Empiric Antibiotic ◽  
Gram Negative Organisms

Abstract Background Bloodstream infections are a leading cause of mortality amongst hospitalized patients. Optimizing time to pathogen identification and receipt of appropriate antibiotic therapy significantly decreases mortality, morbidity, and length of hospitalization. Rapid diagnostic tests, such as Verigene, assist in the early identification of bacteria and resistance determinants from positive blood cultures; however, Verigene assays are limited to the detection of 13 gram-positive and 9 gram-negative bacteria. Methods The purpose of this study was to describe gram-negative and gram-positive aerobic bacteria identified from positive blood cultures with no Verigene target detected and to use the susceptibilities to create an antibiogram to assist in empiric antibiotic selection. A total of 2325 positive blood cultures resulted between January 2017 and October 2018 underwent Verigene testing. Results Of the 2325 isolates, 383 (16.5%), had no Verigene organism or resistance mechanism detected. Of these, there were 239 (62.4%) gram-positive isolates, 141 (36.8%) gram-negative isolates, and 3 yeast isolates with 96 unique organisms. Seventy-six (19.8%) of the organisms identified by standard culture, but not Verigene testing, are included on Verigene panel. We analyzed nine common antibiotics active against gram-negative organisms to determine percent susceptibilities against the isolated aerobic pathogens: amikacin (92.1%), cefepime (93.5%), ceftazidime (94.0%), ceftriaxone (79.7%), ciprofloxacin (88.5%), gentamicin (91.9%), levofloxacin (86.9%), piperacillin–tazobactam (83.8%), and tobramycin (85.5%). Additionally, four antibiotics active against gram-positive organisms were analyzed for gram-positive susceptibilities: cefotaxime (91.8%), ceftriaxone (98.1%), levofloxacin (82.5%), and vancomycin (91.8%). Conclusion The results of this study provide clinicians with antibiotic susceptibilities against organisms that were not identified through Verigene to better guide timely and appropriate antibiotic therapy against gram-negative and gram-positive aerobic bacteria. Disclosures All authors: No reported disclosures.

Early Quantitative Determination of Serum Procalcitonin Can Help Distinguishing Strains of Different Bloodstream Infections in Patients with Hematologic Diseases

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 3703-3703
Author(s):  
Xiaofeng Luo ◽  
Jinhua Ren ◽  
Zhizhe Chen ◽  
Ting Yang ◽  
Jianda Hu
Keyword(s):  
Quantitative Determination ◽  
Bloodstream Infection ◽  
Large Population ◽  
Bloodstream Infections ◽  
Blood Cultures ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Hematologic Diseases ◽  
Fungi Infection

Abstract High procalcitonin (PCT) levels are strongly associated with systemic bacterial infections. PCT is produced in response to bacterial endotoxin and inflammatory cytokines. Few studies are available in the literature on PCT ability to distinguish different strains of bloodstream infections in patients with hematologic diseases. The aim of the present study was to explore the value of determining serum PCT values early, i.e., as soon as blood cultures are positive, in a large population of patients with hematologic diseases. Patients with hematologic diseases admitted to the hematology department of our hospitalfrom January 2013 to March 2016 who had bloodstream infections were retrospectively analyzed. Patients whose blood samples were collected for simultaneous blood culture and PCT test were enrolled in the study, and they were divided into agranulocytosis and non-agranulocytosis groups. Automatic microbial analyzer was used to identify all strains, and PCT levels were analyzed with an automatic electrochemiluminescence system. The relationship between PCT levels and the strains in bloodstream infections was analyzed and compared, and the diagnostic efficacy of PCT was evaluated using the receiver operating characteristic (ROC) curve. A total of 494 bloodstream infection cases that fulfilled the inclusion criteria were included in the study, involving 312 cases of bloodstream infection with single Gram-negative, 146 cases with single Gram-positive, 12 cases with single fungi, 19 cases with polymicrobes, and 5 cases identified as contaminated specimens. Unpaired t-test was used for data analysis. PCT levels for single Gram-negative infection (15.17±2.11 ng/ml) were significantly higher than those for Gram-positive infection (3.30 ± 0.93 ng/ml) (P<0.0001), or those for single fungi infection (0.22 ± 0.04 ng/ml) (P<0.0001). PCT levels for single Gram-positive infection were also significantly higher than those in single fungi infection (P<0.01). In the agranulocytosis group, which included 403 cases, the PCT levels in the single Gram-negative infection (14.14 ± 2.13 ng/ml) were significantly higher than those in single Gram-positive (2.49 ± 0.73 ng/ml) (P<0.0001), or in single fungi infection (0.24 ± 0.04 ng/ml) (P<0.0001). The PCT levels in the single Gram-positive bacterial infection were also significantly higher than those in single fungi infection (P<0.01). In the single Gram-negative bacteria bloodstream infection, we further found that the PCT levels in Enterobacteriaceae infection (17.00 ± 3.04 ng/ml) were significantly higher than those in nonfermentative Gram-negatives infection (6.49 ± 1.50 ng/ml) (P<0.01). ROC analysis was performed on monomicrobial blood cultures. ROC of single Gram-negative and Gram-positive infections revealed that the area under the curve (AUC) was 0.687, the best cut-off value was 0.58 ng/ml, the sensitivity was 60.81% and specificity was 71%. ROC of single Gram-negative and fungi infections revealed that the AUC was 0.795, the best cut-off value was 0.42 ng/ml, the sensitivity was 67% and specificity was 100%. ROC of single Gram-positive and fungi infections revealed that the AUC was 0.6, the best cut-off value was 0.44 ng/ml, the sensitivity was 37% and specificity was 100%. In the non-agranulocytosis group, we only found that the PCT levels in the single Gram-negative infection were significantly higher than those in single Gram-positive infection (P<0.05). In summary, early serum PCT quantitative determination can be used as a routine test to help to distinguish Gram-negative bacteria, Gram-positive bacteria, or fungi bloodstream infections in patients with hematologic diseases. These findings will be of great clinical value to select appropriate antibiotics for patients with hematologic diseases and bloodstream infections. Figure Figure. Disclosures No relevant conflicts of interest to declare.

Development of the iCubate Molecular Diagnostic Platform Utilizing Amplicon Rescue Multiplex Polymerase Chain Reaction

2019 ◽  
Vol 15 (7) ◽  
pp. 1598-1608
Author(s):  
Hongna Liu ◽  
Kathryn Heflin ◽  
Jian Han ◽  
Matt Conover ◽  
Leslie Wagner ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Bacterial Species ◽  
Bloodstream Infections ◽  
Cross Reactivity ◽  
Blood Cultures ◽  
Molecular Diagnostic ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
High Level

We utilized Amplicon-Rescue Multiplex PCR (ARM-PCR) and microarray hybridization to develop and validate the iC-GPC Assay, a multiplexed, in vitro diagnostic test that identifies five of the most common gram positive bacteria and three clinically relevant resistance markers associated with bloodstream infections (BSI). The iC-GPC Assay is designed for use with the iC-System™, which automates sample preparation, ARM-PCR, and microarray detection within a closed cassette. Herein, we determined the limit of detection for each of the iC-GPC Assay targets to be between 3.0 × 105–1.7 × 107 CFU/mL, well below clinically relevant bacterial levels for positive blood cultures. Additionally, we tested 106 strains for assay inclusivity and observed a target performance of 99.4%. 95 of 96 non-target organisms tested negative for cross-reactivity, thereby assuring a high level of assay specificity. Overall performance above 99% was observed for iC-GPC Assay reproducibility studies across multiple sites, operators and cassette lots. In conclusion, the iC-GPC Assay is capable of accurately and rapidly identifying bacterial species and resistance determinants present in blood cultures containing gram positive bacteria. Utilizing molecular diagnostics like the iC-GPC Assay will decrease time to treatment, healthcare costs, and BSI-related mortality.

scholarly journals 2123. Rapid Phenotypic Detection of Gram-Negative Bacilli-Resistant to Oximinocephalosporins and Carbapenems in Positive Blood Cultures Using a Novel Protocol

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S718-S718
Author(s):  
Diego Josa ◽  
Gisell Bustos-Moya ◽  
Soad Yusef ◽  
Stephanie Crevoisier ◽  
Edwin Silva ◽  
...  
Keyword(s):  
Clinical Outcomes ◽  
Bloodstream Infections ◽  
Blood Cultures ◽  
Drug Resistant ◽  
Gram Negative ◽  
Diagnostic Strategies ◽  
Detection Techniques ◽  
Reference Hospital ◽  
Novel Method

Abstract Background Early and adequate antibiotic treatment are the cornerstones to improve clinical outcomes in patients with Bloodstream infections (BSI). Delays in appropriate antimicrobial therapy have catastrophic consequences for patients with BSI. Microbiological characterization of multi-drug-resistant pathogens (MDRP) allow clinicians to provide appropriate treatments. Current available microbiologic techniques may take-up to 96 hours to identify causative pathogens and its resistant patterns. Therefore, there is an important need to develop rapid diagnostic strategies for MDRP. However, rapid detection techniques are costly and are not widely available. We tested a modified protocol designed to detect Gram-negative bacilli (GNB) resistant to oximinocephalosporins and carbapenems from positive blood cultures. Methods This is a prospective, cohort study of consecutive patients with bacteremia. We developed a modified protocol using HB&L® system to detect MDRP. We then attempted to determine accuracy, concordance and reduction of identification time of this novel method in a reference hospital. Descriptive statistics and logistical regressions were used. Results Ninety-six patients with BSI were included in the study. A total of 161 positive blood cultures were analyzed. Escherichia coli (50%, 81/161) was the most frequently identified pathogen followed by Klebsiella pneumoniae (15%, 24/161) and Pseudomonas aeruginosa (8%, 13/161). 32% of isolations had usual resistance patters. However, in 29/161 (18%) of identified pathogens were producer of carbapenemasases and 21/161 (13%) of extended-spectrum β-lactamases. Concordance among our HB&L® modified protocol and traditional method was 99% (159/161). Finally, identification times were significantly shorter using our HB&L® modified protocol than traditional methods (Mean, hours [SD], 20.8 [6.22] vs. 62.8 [6.22], P < 0.001). Conclusion Here we provided novel evidence that using our HB&L® modified protocol is an effective strategy to reduce the time to MDRP detection/identification; with a great concordance rate when compared with the gold standard. Further studies are needed to confirm these findings and to determine whether this method may improve clinical outcomes. Disclosures All authors: No reported disclosures.

Bacteraemia in 66 cats and antimicrobial susceptibility of the isolates (1995–2004)

2007 ◽  
Vol 9 (5) ◽  
pp. 404-410 ◽  
Author(s):  
Martina Greiner ◽  
Georg Wolf ◽  
Katrin Hartmann
Keyword(s):  
Bacterial Species ◽  
Small Animal ◽  
Blood Cultures ◽  
Bacterial Isolates ◽  
Gram Positive ◽  
Gram Negative ◽  
Obligate Anaerobic ◽  
Animal Medicine ◽  
Privately Owned

Bacterial blood culture results of 292 privately owned cats presented to the Clinic for Small Animal Medicine, Ludwig Maximilian University Munich with signs of sepsis were evaluated retrospectively. Of the blood cultures, 23% were positive. In 88%, a single bacterial species was isolated. Of all bacterial isolates, 45% were Gram-positive, 43% were Gram-negative, and 12% were obligate anaerobes. The most frequently isolated bacteria were Enterobacteriaceae, obligate anaerobic species, Staphylococcus species and Streptococcus species. Of the cats with positive blood cultures, 32% were pretreated with antibiotics. Of all bacterial isolates, 77% were susceptible to enrofloxacin, 69% to chloramphenicol, 67% to gentamicin, and 64% to amoxycillin clavulanic acid. Only enrofloxacin reached an in vitro efficacy of more than 70% against Gram-positive and more than 74% against Gram-negative bacteria.

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