Simultaneous Blood Cultures Research Articles

Etiological diagnostic performance of probe capture-based targeted next-generation sequencing in bloodstream infection.

A rapid and precise etiological diagnosis is crucial for the effective treatment of bloodstream infection (BSI). In this study, the performance of probe capture-based targeted next-generation sequencing (tNGS) was compared to that of blood culture and metagenomic next-generation sequencing (mNGS) in detecting potential pathogens in patients with BSI. A total of 80 patients with suspected BSI were prospectively enrolled from 24 November 2023 to 30 December 2023 at Zhongshan Hospital, Shanghai, China. All 80 participants underwent simultaneous blood culture, blood mNGS, and blood tNGS after admission when febrile, and the results were compared. Among the 80 participants, 11 were clinically diagnosed with noninfectious fever, and 69 were diagnosed with BSI. Blood tNGS had a higher sensitivity for the diagnosis of BSI than blood culture (91.3% vs. 23.2%, P<0.001) and blood mNGS (91.3% vs. 69.6%, P=0.001). There was no significant difference in specificity between blood mNGS and tNGS (81.8% vs. 100.0%, P=0.13). Blood tNGS demonstrated a faster turnaround time than blood culture and blood mNGS. In 22 (31.9%) patients with BSI, targeted adjustment of the anti-infectious therapy according to the blood tNGS results resulted in clinical improvement. Blood tNGS may be a promising tool for detecting potential pathogens in patients with BSI. The application of blood tNGS for BSI could guide anti-infectious treatment strategies and might improve clinical outcomes.

Universal Digital High-Resolution Melt Analysis for the Diagnosis of Bacteremia

Fast and accurate diagnosis of bloodstream infection is necessary to inform treatment decisions for septic patients, who face hourly increases in mortality risk. Blood culture remains the gold standard test but typically requires approximately 15 hours to detect the presence of a pathogen. We, therefore, assessed the potential for universal digital high-resolution melt (U-dHRM) analysis to accomplish faster broad-based bacterial detection, load quantification, and species-level identification directly from whole blood. Analytical validation studies demonstrated strong agreement between U-dHRM load measurement and quantitative blood culture, indicating that U-dHRM detection is highly specific to intact organisms. In a pilot clinical study of 17 whole blood samples from pediatric patients undergoing simultaneous blood culture testing, U-dHRM achieved 100% concordance when compared with blood culture and 88% concordance when compared with clinical adjudication. Moreover, U-dHRM identified the causative pathogen to the species level in all cases where the organism was represented in the melt curve database. These results were achieved with a 1-mL sample input and sample-to-answer time of 6 hours. Overall, this pilot study suggests that U-dHRM may be a promising method to address the challenges of quickly and accurately diagnosing a bloodstream infection.

201. Utility of Incorporation of Beta-D-glucan Testing in Algorithms for Diagnosis and Treatment of Candidemia.

Abstract Background Candidemia is a common hospital acquired infection that is associated with significant morbidity and mortality. The optimal strategy for diagnosis remains unknown. Methods We evaluated 2 distinct diagnostic strategies in hospitalized patients with suspicion of Candida bloodstream infection, namely strategy #1 that included simultaneous blood cultures and T2Candida and strategy #2 that included blood cultures, T2Candida testing and Beta-D-glucan (BDG). We examined the consistency with which each diagnostic algorithm led to changes in antifungal prescribing, the overall rate of antifungal utilization and patients’ clinical outcomes. Flow Chart. Figure 1. Results Among 96 patients tested with strategy #1, 3 had a positive result. Of those 100% completed a 14-day antifungal course for candidemia or were on antifungals until hospital discharge. Of the 29 out 120 patients that tested positive with strategy #2, 55.2% received a complete 14-day course or were on antifungals until hospital discharge. The percentage of completed treatment increased to 75.0% and 80.0% when the threshold for BDG positivity was increased at 200 pg/ml and 500 pg/ml respectively. We observed a significant difference in the overall antifungal utilization with 268.5 days of antifungals per 1,000 patient days for strategy #1, as opposed to 371.9 days of antifungals for strategy #2, a 38.5% increase. Negative tests at both diagnostic strategies led to a similar rate of antifungal discontinuation 3 days after testing (36.8% and 37.0% for strategy #1 and #2 respectively). We did not find significant benefits in death and/or subsequent diagnosis of candidemia between the 2 diagnostic strategies. Sensitivity analyses performed based on indication for testing and severity of illness did not significantly alter results. Table 1.Characteristics of patients tested for suspicion of candidemia with the 2 diagnostic strategies. Figure 2. Duration of antifungal therapy among patients with positive BDG at different thresholds A. BDG&amp;lt;80 pg/ml, B. BDG&amp;lt;200 pg/ml, C. BDG&amp;lt;500 pg/ml. Figure 3. Percentage of patients who were taken off antifungals within 3 days of testing for different BDG thresholds, BDG&amp;lt;80 pg/ml, BDG&amp;lt;200 pg/ml, and BDG&amp;lt;500 pg/ml. Conclusion In summary, the addition of BDG in diagnostic algorithms for candidemia was interpreted variably by clinicians, was associated with a significant increase in antifungal utilization, and it did not appear to lead to measured clinical benefits for patients. Diagnostic strategies of common and serious infections that incorporate non-culture diagnostics need to be evaluated for added benefit. Table 2.Antifungal utilization among patients tested for suspicion of candidemia with the 2 diagnostic strategies. Table 3. Outcomes among patients tested for suspicion of candidemia with the two different diagnostic strategies. Disclosures All Authors: No reported disclosures.

Central Venous Catheter Related Bloodstream Infections in Medical Intensive Care Unit Patients in a Tertiary Referral Centre

To determine the incidence of central line associated bloodstream infections (CLABSIs) in the medical intensive care unit (ICU) and ward setting at All India Institute of Medical Sciences (AIIMS), New Delhi. The study was conducted in the medical ICU, a 9-bedded ICU at the AIIMS, a tertiary care teaching hospital. The study design was a prospective observational study. One hundred patients admitted to medical ICU and the ward at AIIMS with an indwelling, non-tunnelled central venous catheter (CVC) in place at admission and those with a hospital stay with indwelling CVC for more than 48 hours were monitored. These patients were followed daily for the development of new onset sepsis 48 hours after insertion of CVC, in which case three sets of blood samples for culture were drawn over a span of 24 hours. Incidence of CLABSIs was measured per 1000 central line days. One hundred patients hospitalised for an aggregate 1119 days acquired 29 hospital-acquired infections (HAIs), a rate of 38.8% or 31.2 HAIs per 1000 hospital days. The incidence of bloodstream infections (BSIs) in this group was 6.8%. No case of laboratory confirmed CLABSIs could be demonstrated. Incidence of clinical sepsis was 27.6% or 8.2 per 1000 CVC days. There were 9 cases out of the 29 patients (39.7%) who had evidence of HAIs with no apparent focus of infection. Only one of these cases had evidence of BSI with isolation of Staphylococcus aureus in both CVC tip culture and the simultaneous blood culture; however the antibiograms were different. The low rate of BSIs in the present study and the absence of occurrence of a laboratory confirmed CLABSI should be interpreted in the light of the small sample size of the study and the multitude of antibiotics received before the development of HAI.

Molecular diagnosis of bacteremia in a pediatric intensive care unit: astep forward.

Aim: T2Bacteria® Panel detects sixESKAPE pathogens in around 3.5hdirectly in whole blood. Our aim was to compare T2Bacteriawith simultaneous blood culture in critically ill children with suspected bloodstream infection. Materials & methods: Retrospective study of critically ill children admitted to our tertiary-care center (2018-2020). Results: A total of 60 patients were recruited, including 63 episodes and 75 T2Bacteria/blood cultures were performed. Overall agreement between T2Bacteriaand blood culture was 78.7% with a discordance of 21.3% (16/75 samples). Conclusion: T2Bacteria Panel may be useful in critically ill children providing an accurate and fast diagnosis of bacteremia directly from blood sample and detecting pathogens not recovered in blood cultures.

Neonatal Nasopharyngeal Bacterial Colonization: Prevalence, Antimicrobial Resistance, and Concomitant Early-onset Sepsis

Background: Early-onset neonatal sepsis (ENOS) is one of the most common causes of mortality in neonates. The bacteria causing ENOS are generally transferred from the mother to the infant before or during labor. Objectives: This study aimed to determine the prevalence rate of nasopharyngeal colonization with common bacterial agents causing ENOS and their relationship with blood culture outcomes in neonates. Methods: All neonates transferred to the neonatal intensive care unit were included in the study. Posterior pharynx secretions were swabbed and cultured in blood agar and MacConkey agar. Also, a blood specimen from each neonate was inoculated into a blood culture bottle. The grown bacteria were identified by biochemical standard tests. The antibiotic sensitivity test was performed by the disk diffusion method using Mueller-Hinton agar, and the results were evaluated according to the CLSI guidelines. Results: The pharyngeal specimens collected from 114 newborns were positive in 83 (72.8%) cases. Staphylococcus epidermidis was the most common bacterium in all weight groups. However, the isolates of Klebsiella, Escherichia coli, S. aureus, and Streptococcus agalactiae were also high. Thirteen newborns died. Neonates’ pharyngeal specimens were positive among 11 (84.6%) cases who died and 101 (71.2%) neonates who survived. Twelve neonates had positive blood cultures. Simultaneous positive blood and pharyngeal cultures were reported in eight (7%) cases, in which the bacterial isolates from blood and pharyngeal samples were similar in three cases (37.5%). Among pharyngeal isolates, E. coli was resistant to ampicillin in 100% and gentamicin, cefotaxime, and ceftazidime in 50% of the cases. Also, S. epidermidis and Acinetobacter isolates from blood samples were resistant to ampicillin in 100% of the cases. Conclusions: Staphylococcus epidermidis accounted for 38.6% of bacteria cultured from pharyngeal swabs and 66.7% of bacteria cultured from blood samples, 37.5% of which were resistant to ampicillin and 100% were sensitive to vancomycin. One-hundred percent of E. coli cultures from neonatal pharynges were resistant to ampicillin and about 50% of them were resistant to gentamicin, cefotaxime, and ceftriaxone.

Plasma Microbial Cell-Free DNA Sequencing Technology for the Diagnosis of Sepsis in the ICU.

Sepsis is a common life-threatening disease in the intensive care unit (ICU) that is usually treated empirically without pathogen identification. As a non-invasive and high-throughput technology, plasma microbial cell-free DNA (mcfDNA) sequencing can detect unknown pathogens independent of previous clinical or laboratory information. In this study, a total of 199 cases suspected of bloodstream infection (BSI) from January 2020 to June 2020 were collected, and potential pathogens were detected by simultaneous blood culture and plasma mcfDNA sequencing. Other clinical microbiological assays were performed within 7 days of plasma mcfDNA sequencing, including smear, culture of samples taken from relevant infected sites, and β-D-glucan/galactomannan (BDG/GM) tests, among others. The diagnoses were classified as sepsis [94 (47.2%)], non-sepsis [87 (43.7%)], and non-infectious disease [18 (9.0%)]. The sensitivity and specificity of plasma mcfDNA sequencing for diagnosing sepsis were 68.1 and 63.2%, respectively, which were significantly better than those of blood culture, especially for the common bacteria that cause hospital-acquired infection, namely, Acinetobacter baumannii (p < 0.01) and Klebsiella pneumoniae (p < 0.01), and DNA viruses (plasma mcfDNA sequencing only, p < 0.01). However, there was no significant difference in the rate of positivity between plasma mcfDNA sequencing and blood culture for antibiotic-non-exposed cases (43.6 vs. 30.9%, p = 0.17). In the non-sepsis group, 44.8% of cases (13/29) detected only by plasma mcfDNA sequencing showed infections in other parts of the body, such as lower respiratory infection (LRI), intra-abdominal infection (IAI) and central nervous system infection (CNSI). For some common pathogens (not including anaerobes), turnaround time (TAT) 3 (TAT from the initiation of blood sample processing by nucleic acid extraction to the completion of sequencing analysis) was longer than TAT1 (TAT from blood culture bottles in Virtuo to off Virtuo). With disease progression, significant dynamic changes in microbial species were clearly detected by plasma mcfDNA sequencing.

Evaluation of Brucella Coombs Gel Test with Blood Culture

Objective: To evaluate the correlation between Brucella spp. blood culture, which is accepted as the gold standard in the diagnosis of brucellosis, and the Brucella coombs gel test (BCGT), a new and rapid test developed in our country.&#x0D; Material and method: Brucellosis is suspected in 100 patients from various clinics of our hospital microbiology laboratories, simultaneous blood culture results (Bactrim / allet 3D bioMerieux, France) and serum standard tube agglutination test (STA Seromed, Turkey), Brucella Coombs gel test (BCGT, Islab, Turkey) It was evaluated retrospectively.&#x0D; Results: Serology and blood culture growth were negative in 82/100 of the patients. STA/ BCGT results were consistent in 18/100, and ≥ 1/320 was positive. Brucella Melitensis was isolated from blood cultures of seven patients and concurrently taken BCGT was positive (100%). There are 11 patients with positive serology with culture-negative.&#x0D; Conclusion: Although blood culture is accepted as gold standard, it is not always possible to catch blood culture positivity. Serology tests, especially BCGT, should be preferred routinely because it gives early results, is cheap and safe.

Bacterial Meningitis in the Absence of Pleocytosis in Children: A Systematic Review.

One of the main features of bacterial meningitis is pleocytosis. However, when children with meningitis present within hours of onset of symptoms, there is the possibility that the meninges are not yet sufficiently inflamed to lead to a raised cerebrospinal fluid (CSF) white blood cell count. A systematic search was done to identify published studies reporting children with culture- or polymerase chain reaction-proven bacterial meningitis in the absence of pleocytosis. We identified 26 studies describing 62 children (18 neonates). In those in whom fever duration was specified, 32 (80%) of 40 had a fever for less than or equal to 24 hours before lumbar puncture (LP). In those in whom the glucose level was reported, it was normal in 14 (82%) of 17 neonates and 33 (80%) of 41 older infants and children. The protein level was normal in 8 (44%) of 17 neonates and 32 (80%) of 40 older infants and children. Twelve of the 62 children had a Gram stain of their CSF and this was positive in 2 (17%). Simultaneous blood cultures were positive in 5 (28%) of 18 neonates and 21 (68%) of 31 older infants and children. There was no association between the absence of pleocytosis and particular bacteria. All of the 10 children who had a second LP had an abnormal CSF including pleocytosis. These findings indicate that the absence of pleocytosis does not exclude bacterial meningitis reliably and should be interpreted in the context of the duration of illness. CSF samples, particularly those from cases with relatively short symptom duration, should be cultured even when the cell count and biochemistry are normal. A second LP can be helpful when bacterial meningitis is suspected despite a normal initial CSF.

Candidemia Diagnosis With T2 Nuclear Magnetic Resonance in a PICU: A New Approach

Early diagnosis of invasive Candida infections is a challenge for pediatricians, intensivists, and microbiologists. To fill this gap, a new nanodiagnostic method has been developed using manual application of T2 nuclear magnetic resonance to detect Candida species. The aim of this study was to evaluate, prospectively, the usefulness as a tool diagnosis of the T2Candida panel in pediatric patients admitted at the PICU compared with blood culture. This is a prospective, observational, and unicentric study to compare T2Candida results with simultaneous blood cultures for candidemia diagnose. This study was carried out in a 1,300-bed tertiary care hospital with a 16-bed medical-surgical PICU. Sixty-three patients from 0 to 17 years old were enrolled in this study, including those undergoing solid organ transplantation (kidney, liver, pulmonary, multivisceral, intestinal, and heart) and hematopoietic stem cell transplantation. Seven patients were positive by the T2Candida test. Only two of them had the simultaneous positive blood culture. T2Candida yielded more positive results than blood cultures. T2Candida might be useful for the diagnosis of candidemia in PICUs. The prevalence of candidemia might be underestimated in this pediatric population. The use of this diagnostic tool in these units may help clinicians to start adequate and timely antifungal treatments.

Fast I(n)dentification of Pathogens in Neonates (FINDPATH-N): protocol for a prospective pilot cohort study of next-generation sequencing for pathogen identification in neonates with suspected sepsis

IntroductionSepsis is a major source of morbidity and mortality in neonates; however, identification of the causative pathogens is challenging. Many neonates have negative blood cultures despite clinical evidence of sepsis....

Elevated serum procalcitonin predicts Gram-negative bloodstream infections in patients with burns

BackgroundMany studies have suggested that procalcitonin can predict bloodstream infection and also distinguish between Gram-negative, Gram-positive and fungal infections after burn. However, up to now, there is no literature on serum procalcitonin level of multidrug-resistant pathogens and non-multidrug-resistant pathogens among Gram-negative bloodstream infections after burn. The purpose of this study is to explore the value of serum procalcitonin in identifying Gram-negative bloodstream infection in patients with febrile critical burn and then to investigate the difference of serum procalcitonin level between multidrug-resistant pathogens and non-multidrug-resistant pathogens among Gram-negative bloodstream infections after burn. MethodsPatients with febrile critical burn admitted to the burn department of our hospital from 1 January 2014 to 1 August 2018 were retrospectively analysed. Patients with positive blood culture whose blood samples were collected for simultaneous blood culture and procalcitonin testing were enrolled. All strains were identified by an automatic microorganism analyser, and procalcitonin was analysed by an automatic electrochemiluminescence immunoassay. ResultsOverall, a total of 119 patients with positive blood culture met the inclusion criteria. There were 64 Gram-negative bacilli, 38 Gram-positive bacteria, 8 C. albicans and 9 polymicrobial bloodstream infections. The median procalcitonin value in Gram-negative bloodstream infections (2.67 ng/mL, interquartile range (IQR) 1.58–6.08) was significantly higher than that in Gram-positive bloodstream infections (1.04 ng/mL, IQR 0.35–1.60, P < 0.01), or C. albicans bloodstream infections (1.09 ng/mL, IQR 0.82–2.30, P < 0.05). Receiver operating characteristic curve (ROC) analysis showed that in addition to polymicrobial bloodstream infections, the area of procalcitonin under the curve distinguishing Gram-negative bloodstream infections from all other blood culture-positive bloodstream infections was 0.761, the best critical value was 1.73 ng/mL, the sensitivity was 73%, the specificity was 74%, the positive predictive value was 80%, the negative predictive value was 67%, The level of procalcitonin was significantly higher in multidrug-resistant Gram-negative bacilli (A. baumannii, Klebsiella pneumoniae and Pseudomonas aeruginosa) (2.76 ng/mL, IQR 2.01–7.76) than in non-multidrug-resistant bacilli (1.01 ng/mL, IQR 0.58–1.56, P < 0.01). ConclusionElevated serum procalcitonin can identify Gram-negative bloodstream infections in patients with febrile critical burn. In Gram-negative bloodstream infections, high procalcitonin levels may be associated with multidrug-resistant Gram-negative bacilli (A. baumannii, K. pneumoniae and P. aeruginosa).

Evaluation of simultaneous blood and cerebrospinal fluid culture findings in neonatal meningitis

Purpose: The aim of our present study was to investigate the simultaneous findings of both blood and cerebrospinal fluid cultures and to determine the etiological pathogens responsible for neonatal sepsis and meningitis in our neonatal intensive care unit.Materials and Methods: This study was carried out in our newborn department from November 2013 to October 2015. During this period 732 neonates with signs and symptoms of neonatal sepsis were included in our study. Sepsis and meningitis work up were performed and simultaneous blood and cerebrospinal fluid cultures were taken from eligible patients.Results: Cerebrospinal fluid cultures were positive in100 (13.7%) of cases. Positive blood cultures were found in 59 (8.1%) neonates with meningitis. Staphylococcus bacteria (48%) was the most frequent organism responsible for confirmed meningitis, followed by klebsiella (19%) and pseudomonas (10%). Simultaneous pathogens isolated from blood cultures were Staphylococcus (%24), klebsiella (13%) and pseudomonas (8%).Conclusion: In our study group staphylococcus, klebsiella and pseudomonas were the main etiological agents that were responsible for neonatal sepsis and meningitis in our unit.

Cervical bacterial colonization in women with preterm premature rupture of membrane and pregnancy outcomes: A cohort study

One of the most important etiologies in pretermpremature rupture of membranes (PPROM) is cervical bacterial colonization. This study evaluated cervical bacterial colonization in women with PPROM and the pregnancy outcomes. In this cohort study, 200 pregnant women with PPROM at 27-37 wk of gestation who were admitted in an academic hospital of Mashhad University of Medical Sciences from March 2015 to July 2016 were studied. samples were obtained from endocervical canal for detection of routine bacteria and Gram staining. Also, we obtained one blood culture from neonates. Maternal endocervical culture, chorioamnionitis, neonatal intensive care unit admission, neonatal positive blood culture, neonatal sepsis, and mortality were documented. Most common isolated microorganism of endocervical culture were Escherichia coli (24.2%), Coagulase negative Staphylococci (27.2%), Enterococcus and candida each one (11.7%). The prevalence of GBS was only 2.2%. Simultaneous positive blood cultures were seen in 3% of neonates. Among them, Gram-negative bacilli accounted for (66.6%), while Gram-positive cocci and candida made up only (16.7%). Endocervical colonization was associated with a higher admission rate (p=0.004), but there was no significant correlation between endocervical colonization and chorioamnionitis, positive blood culture and neonatal mortality rate. With regard to low GBS colonization rate, appropriate antibiotic regimens should be considered in PPROM cases according to the most prevalent micro organisms of endocervical bacterial colonization. Maybe cervical bacterial colonization had some effects on neonatal outcomes. There was no significant association between endocervical bacterial colonization and chorioamnionitis, positive neonatal blood culture and neonatal mortality.

Improvement in the diagnosis of catheter-related bloodstream infections in a tertiary cancer center.

Identifying a central venous catheter (CVC) as the source of bacteremia requires drawing simultaneous blood cultures (BCs) from the CVC and peripheral site and correct labeling of the BC source. In our emergency center (EC), 52% of BCs collected from febrile cancer patients lacked source information, making the diagnosis and management of catheter-related bloodstream infections (CRBSIs) challenging. Between January 2015 and June 2015, we conducted a quality improvement project in our EC aiming to increase the occurrence of simultaneous BC drawing with accurate source labeling by 10%. Staff education and monitoring increased average BC source labeling from a baseline of 48% to a much better rate of 70%. Label introduction led to increased source labeling to 94% by June 2015. This project had a significant influence in patients with a CVC and a positive BC because the physician is now able to determine whether the CVC is the source of the bacteremia in 88% of cases compared with 36% at baseline (P = .0003). Education without an active intervention is usually not enough. Simple solutions such as label introduction can have significant influence on patient safety and care. Accurate diagnosis may guide clinicians at the bedside to appropriately manage CVCs in the setting of bacteremia, remove a CVC when indicated, and prevent unnecessary CVC removal with its potential safety and cost-effectiveness implications.

Simultaneous Two-site Blood Culture for Diagnosis of Neonatal Sepsis.

To evaluate efficacy of two blood cultures taken simultaneously from two different sites as compared to standard practice of single blood culture in diagnosis of neonatal sepsis. Prospective cohort study. A tertiary-care center at a public hospital. 475 neonates admitted to intensive care unit with suspected sepsis, from August 2014-July 2015. Two blood cultures drawn from two different peripheral veins in patients with suspected neonatal sepsis. Increase in culture-positivity rate with use of two blood cultures. 475 babies with suspected sepsis were enrolled. 185 patients had only first culture positive (38.9%). When we added second culture positivity, yield increased to 221 (46.5%). Adding on second culture increased the culture yield by 36 (7.6%; 95% CI 2.41 to 12.79; P=0.018). The most common organisms isolated were E. coli, S. aureus and Candida spp. Major morbidities and mortality were more common in blood culture positive patients Contamination was ruled out in 25 babies who grew Coagulase negative Staphylococcus (CONS) (n=10) and Candida spp. (n=15) in either of the two cultures. Two blood cultures taken simultaneously from two different sites improve rate of pathogen detection as compared to routine practice of single blood culture.

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

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. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

A review of intravascular catheter tip cultures and simultaneous blood cultures done for the diagnosis of CRBSI in a tertiary care hospital

A review of intravascular catheter tip cultures and simultaneous blood cultures done for the diagnosis of CRBSI in a tertiary care hospital

Etiology and antimicrobial resistance patterns of acute bacterial meningitis in children: a 10-year referral hospital-based study in northwest iran.

Background:Bacterial meningitis is still considered as one of the most dangerous infectious diseases, which causes numerous complications and high mortality if not diagnosed and treated timely.Objectives:This study was performed to determine antimicrobial resistance patterns of bacterial pathogens isolated from acute bacterial meningitis at Tabriz Children Educational-Health Care Center in Iran.Patients and Methods:In a retrospective study (from 2003 through 2013), all patients with bacterial meningitis were identified by cerebrospinal fluids with positive results in culture (107 cases). Patients' necessary data was recorded in a questionnaire. Furthermore, the results of simultaneous blood culture were also examined. Ultimately, antimicrobial susceptibility of isolates was determined using the disc diffusion method.Results:One hundred and seven patients with bacterial meningitis were identified by cerebrospinal fluids with positive results in culture. All of patients (100%) had fever (male/female = 1.27/1). The most prevalent pathogens isolated from CSF culture were Streptococcus pneumoniae (34.5%), Haemophilus influenzae type b (23.36%), Neisseria meningitidis (6.54%), Serratia spp. (6.54%), and Klebsiella pneumoniae (5.6%), respectively. Moreover, the patients' blood culture had positive results in 36.44% of cases with H. influenzae type b (20.65%) and S. pneumoniae (6.54%) as the main bacteria isolated from blood. Meningitis occurred mostly in children under two years (P = 0.001). According to antimicrobial susceptibility test, a relatively high resistance was reported against some conventional cephalosporins and other antibiotics.Conclusions:S. pneumoniae and H. influenzae type b were the main pathogens of bacterial meningitis in children in the area under study. Most species had relatively high resistance to conventional antibiotics as compared to the past.

Limitation of the delta neutrophil index for assessing bacteraemia in immunocompromised children

BackgroundDelta neutrophil index (DNI) has been reported to be useful in assessing the prognosis of suspected bacteraemia in adults. However, data in children are limited. The purpose of this study was to investigate the correlation between the DNI and bacteraemia in children and to compare DNI values between immunocompetent and immunocompromised hosts. MethodsWe retrospectively collected data on 8593 children who underwent simultaneous blood culture and DNI testing. DNI was determined with a blood cell analyser (ADVIA 120, Siemens, Inc.). The children were divided into immunocompromised (n=664) and immunocompetent groups (n=7929). ResultsDNI was higher in the bacteraemia group than in the non-bacteraemia group (P<0.001). According to the group, DNI was higher in immunocompromised than immunocompetent patients (P<0.001). Within the immunocompromised group, there was no significant difference between the bacteraemia and non-bacteraemia subgroups due to a higher DNI as compared to the immunocompetent group. ConclusionsDNI could be an additional method for the early diagnosis of bacteraemia in children. However, the use of DNI for the prediction of bacteraemia in immunocompromised cases has limitations. Further studies on the usefulness of DNI according to specific diseases are needed.