Conventional Blood Culture Method Research Articles

Microbial cell-free DNA-sequencing as an addition to conventional diagnostics in neonatal sepsis.

Bloodstream infections remain a challenge for neonatologists, as traditional culture-based methods are time-consuming and rely on adequate blood volume. Next-generation sequencing (NGS) offers an alternative, as it can identify microbial cell-free DNA (mcfDNA) in a small blood sample, providing rapid pathogen detection. This study aimed to assess the diagnostic performance of DISQVER®-NGS compared to blood cultures in neonatal patients with suspected sepsis. In neonates with suspected sepsis, blood cultures and samples for NGS were prospectively collected. Patients were divided into four categories: 1) sepsis, blood culture positive, 2) clinical sepsis, culture negative, 3) suspected sepsis, 4) validation cohort. NGS detected bacterial, viral or fungal mcfDNA in 24 of 82 samples. Blood cultures were collected in 46 of 84 patients (15/46 positive). DISQVER® correctly identified pathogens in 9/15 patients with a positive blood culture, two with intrinsic resistance to their antibiotic regimen. In seven samples NGS reported the mcfDNA of bacteria that could have theoretically grown in culture but did not. NGS may enhance sensitivity in sepsis diagnostics by detecting mcfDNA in neonates with suspected sepsis. Interpreting NGS results requires correlation with clinical data, laboratory values, and routine microbiological tests for a comprehensive understanding of the patient's condition. Conventional blood culture methods have limitations in accuracy and turnaround time. The study aimed to investigate the diagnostic performance of the Next-Generation Sequencing method DISQVER® compared to traditional blood cultures in neonatal patients with suspected sepsis. Our findings suggest that NGS has the potential to augment the precision of conventional diagnostic techniques, can lead to improved detection of pathogens and targeted treatment approaches in neonatal sepsis. It is emphasized that further validation and integration with clinical and microbiological data are required to ensure optimal clinical utility.

Identification of sepsis-causing bacteria from whole blood without culture using primers with no cross-reactivity to human DNA

Sepsis is a major health concern globally, and identification of the causative organism usually takes several days. Furthermore, molecular amplification using whole blood from patients with sepsis remains challenging because of primer cross-reactivity with human DNA, which can delay appropriate clinical intervention. To address these concerns, we designed primers that could reduce cross-reactivity. By evaluating these primers against human DNA, we confirmed that the cross-reactivity observed with conventional primers was notably absent. In silico PCR further demonstrated the specificity and efficiency of the designed primers across 23 bacterial species that are often associated with sepsis. When tested using blood samples from sepsis patients, the designed primers showed moderate sensitivity and high specificity. Surprisingly, our method identified bacteria even in samples that were detected at other sites but tested negative using conventional blood culture methods. Although we identified some challenges, such as contamination with Acetobacter aceti due to the saponin pretreatment of samples, the developed method demonstrates remarkable potential for rapid identification of the causative organisms of sepsis and provides a new avenue for diagnosis in clinical practice.

A Comparative Study of Conventional and Automated Blood Culture System in Adult Patients

Introduction: Blood culture is considered as the gold standard for the diagnosis of bloodstream infection. Conventional blood culture system is less sensitive and takes longer duration for the detection of bloodstream infections whereas automated blood culture system is more sensitive and rapid in detecting causative organisms of bloodstream infections. This prospective study was undertaken to compare the automated blood culture system with the conventional blood culture system for the identification of microbial pathogens in bloodstream infections. Method: This prospective study was done in Department of Microbiology, Silchar Medical College & Hospital, Silchar for a period of 7 months from November 2021 to May 2022. Blood samples from the patients were inoculated into BD BACTEC Plus Aerobic culture vials for automated blood culture system and Brain Heart Infusion broth for conventional blood culture system. Positive bottles flagged by the automated machine were isolated and identified by doing routine subcultures on Blood agar and MacConkey agar and necessary biochemical tests. The conventional blood culture bottles were processed as per standard protocols. Result: Out of 123 samples, 21(17.09%) showed culture positivity by automated blood culture method and 15(12.19%) showed culture positivity by conventional blood culture method. The most common isolate was Staphylococcus aureus followed by Escherichia coli in automated method whereas the most common isolate in conventional method was Staphylococcus aureus followed by Klebsiella pneumoniae. Conclusion: This study concluded that automated blood culture method is more sensitive than conventional method and detects the presence of microorganisms rapidly causing bloodstream infections. Keywords: Bloodstream infection, Automated blood culture, Conventional blood culture

Metagenomic Next-Generation Sequencing for the Microbiological Diagnosis of Abdominal Sepsis Patients.

ObjectivesFor patients with intra-abdominal infection (IAI), the rapid and accurate identification of pathogens remains a challenge. Metagenomic next-generation sequencing (mNGS) is a novel technique for infectious diseases, but its application in IAI is limited. In this study, we compared the microbiological diagnostic ability of plasma mNGS with that of conventional peritoneal drainage (PD) culture in critical care settings.MethodsFrom January 2018 to December 2020, a prospective observational study was performed at a tertiary teaching hospital in China and data on 109 abdominal sepsis patients were collected. The pathogen detection performance of plasma mNGS and PD culture method were compared.Measurements and ResultsNinety-two positive cases detected on PD culture, while plasma mNGS detected 61 positive cases. Forty-five patients (44.0%) had at least one matched pair of plasma mNGS and PD culture results. Compared with PD culture, the plasma mNGS was more rapid (27.1 ± 4.0 vs. 68.9 ± 22.3 h, p < 0.05). The patients received initial antibiotic treatment matched with mNGS detection showed better clinical outcomes.ConclusionFor abdominal sepsis patients, plasma mNGS can provide early, noninvasive, and rapid microbiological diagnosis. Compared with conventional PD smear, culture, and blood culture methods, plasma mNGS promote the rapid detection of pathogenic bacteria.

Study of antimicrobial resistance pattern in blood isolates from critical care unit at a Tertiary Care hospital, Udaipur, Rajasthan

Introduction: Microorganisms present in circulating blood are a threat to the every organ of the body. Blood stream infections can have serious consequences and timely detection and identification of blood stream pathogen is one of the most important functions of microbiology laboratory. Positive blood culture helps in providing a specific etiological diagnosis and antimicrobial susceptibility pattern. The present study was undertaken to find the pattern of etiological agents of BSI & their antimicrobial susceptibility. Materials and Methods: A study was carried out from July 2016 to December 2017 at a tertiary care hospital, Udaipur, Rajasthan, India using conventional blood culture method. Organisms were identified by standard microbiological procedures and antibiotic sensitivity was performed using the kirby-bauer disk diffusion method. Result and Discussion: A total of 800 samples of suspected blood stream infections (BSI) were included during the study period. Bacterial growth was obtained in 299 samples (37.37%). Gram-positive cocci accounted for 53.16% and Gram negative for 46.50% and candida species as 0.33% of positive cultures. Coagulase negative staphylococcus (38.12%), Staphylococcus aureus (13.04%), Pseudomonas species (13.71%) and Klebsiella species were predominant organisms. The antimicrobial susceptibility pattern of blood isolates showed high resistance to routinely used antimicrobial agents. Conclusion: This emphasizes the importance of institutional antibiotic policy, stringent infection control practices and judicious use of antibiotics. Keywords: BSI, Antimicrobial resistance, Blood isolates.

Evaluation of the diagnostic performance of panfungal polymerase chain reaction assay in invasive fungal diseases.

Timely diagnosis of invasive fungal diseases (IFDs) is important, as delays in treatment initiation are associated with increased mortality rates. However, early diagnosis of IFDs in immunocompromised patients remains difficult. The conventional diagnostic methods currently used for IFDs are not sufficiently effective. Molecular tests, such as polymerase chain reaction (PCR)-based assays, have great potential to improve the early diagnosis of IFDs due to their sensitivity and specificity. In the present study, the diagnostic performance of panfungal PCR assays in IFD patients who received bone marrow transplantation was evaluated. The results suggested that panfungal PCR assay offered a quick and convenient guide for clinical decision-making by identifying higher numbers of fungal species in comparison with the conventional blood culture method. Furthermore, panfungal PCR assay exhibited a sensitivity of 93% and a specificity of 71% in the diagnosis of IFD patients based on the EORTC/MSG criteria. Thus, the present study concluded that the reported PCR-based method was effective and sensitive in early IFD diagnosis and should be integrated into clinical decision-making for the treatment of IFDs in the future.

Comparison of the Lytic Blood Culture Method with the Conventional Blood Culture Method in Cases of Enteric Fever in a Tertiary Care Hospital

Background: Blood Culture is the gold standard and accurate method of diagnosing bacteremia in enteric fever; however, conventional blood culture is slow in isolating Salmonella typhi and Salmonella paratyphi.Objective: The main aim of this study was to compare the result of the lytic centrifugation method with conventional blood culture system for the accurate diagnosis of enteric fever in febrile patients.Methodology: The cross-sectional study was carried out in the department of Microbiology, Mymensingh Medical College, Mymensingh between July 2010 and June 2011 including 200 individuals of different ages and sexes. Of them, 150 were clinically suspected cases of typhoid fever and 50 controls comprising of 25 non-typhoidal febrile patients and 25 healthy individuals. Both types of blood culture were performed for each of the cases and controls.Result: The lytic centrifugation method recovered more organisms (17.3%) than the conventional blood culture method (13.3%). Time required for isolation of S. typhi and S. paratyphi A was short in lytic method (18-20hours) than conventional method (42-72hours). Total contamination rate was 0.5% by lytic as compared to the conventional blood culture method which was 5.0%.Conclusion: In conclusion the lytic method is better than conventional blood culture system for good result, short isolation time and less chance of contamination.Bangladesh Journal of Infectious Diseases 2016;3(1):6-10

Usefulness of matrix-assisted laser desorption ionization time-of-flight mass spectrometry to identify pathogens, including polymicrobial samples, directly from blood culture broths.

Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (TOF-MS) is now widely used to detect pathogens in clinical settings in Japan. Here, we report the ability of TOF-MS to detect bacteria from blood culture (BC) broths, and compare the efficacy of TOF-MS to that of conventional culture methods. Bacteria were correctly detected from 63 monomicrobial samples within 80 minutes; results matched those obtained by conventional BC methods, although the conventional methods took 2–3 days. In addition to the 63 monomicrobial samples, another three polymicrobial samples were tested; notably, the infecting bacteria were not correctly identified in two of these three samples. To better assess the TOF-MS detection of polymicrobial samples, we tested various ratios of mixed broth samples, including combinations of the bacteria that we were unable to detect in clinical samples. Combinations of Enterobacter cloacae and Pseudomonas aeruginosa were correctly detected at a culture ratio of 2:1, but not in the 3:1 mixture. These results suggested that TOF-MS is a strong tool for the rapid and correct detection of pathogens from monomicrobial BC samples, though results need to be carefully checked when handling known or suspected polymicrobial samples.

COMPARATIVE EVALUATION OF BLOOD CULTURE BY CONVENTIONAL METHOD AND BACTEC USING BLOOD SAMPLES OF ICU PATIENTS and ANTIBIOGRAM OF ISOLATED PATHOGENS

Introduction: Sepsis is the leading cause of death in Intensive ICU patients worldwide.Blood cultures are the 'gold standard' for identifying pathogens causing septicemia and in directing appropriate antibiotic therapy.The present study was aimed to compare sensitivity of automated BACTEC 9120 blood culture system and conventional blood culture method in identifying true pathogenic organism, to compare the time needed for the detection of microorganisms by conventional method of blood culture and by automated BACTEC 9120 blood culture system and to evaluate the susceptibility pattern of antibiotics for pathogens isolated. Material and Methods: Study was done over a period of one year from April 2015 to March 2016. A total of 636 blood samples were collected andsubjected to blood culture by BACTEC 9120 and conventional method. The statistical tests applied were Sensitivity, Specificity, Positive predictive value, Negative predictive value, T-test and kappa statistics. Results: Out of 636 blood samples clinically significant isolates were recovered from 85 samples by BACTEC, of which 74 were bacterial pathogens and 11 were candida. In conventional method out of 80 significant isolates 69 were bacterial and 11 were candida. Gram positive (majority Staphylococci) were more commonly isolated than Gram negative (majority Acinetobacter and E.coli). Mean time to detect was 19.47 hours and 3.02 days, by BACTEC 9120 and conventional method respectively. Vancomycin, Teicoplanin and Linezolid were found to be the most effective (100%) for gram positive bacteria and for gram negative bacteria Colistin (70-100%), Polymyxin-B (70-100%) were the most effective. Conclusion: Sepsis is associated with prolonged hospital stay, increased costs and with a high mortality. The use of BACTEC BD blood culture system is better for rapid identification of blood borne pathogens followed by determining actual antimicrobial treatment in the scenario of multi drug resistance so as to improve patient's outcome.

Emergence of Salmonella Paratyphi A and Submergence of Salmonella Typhi and Their Trend Over Four Years

Background: Enteric fever is classically caused by Salmonella enterica serotype Typhi. There has been increase in enteric fever cases from different parts of India caused by Salmonella enterica serotype Paratyphi A. Thereby a retrospective study was conducted to determine the rate of isolation and antimicrobial susceptibility pattern of Salmonella Paratyphi A in comparison to Salmonella Typhi. Methods: A retrospective analysis of laboratory records was carried out from January 2011-December 2014. Conventional blood culture method was used. Salmonella were confirmed by serotyping using group and type specific anti-sera. Antibiotic susceptibility was performed for ampicillin, cotrimoxazole, ciprofloxacin, chloramphenicol and ceftriaxone, using Kirby Bauers disk diffusion method. Results: Out of 258 Salmonella isolates, 127 (49.2 %) were Salmonella Typhi and 131 (50.8 %) were Salmonella Paratyphi A. Salmonella Paratyphi A cases increased from 23.4% in 2011-2013 to 91.3% in 2014. Salmonella Typhi were 98.4 % sensitive to ampicillin and ceftriaxone and 99.2% sensitive to chloramphenicol and cotrimoxazole. Only 29.9% were sensitive to ciprofloxacin. Similarly, Salmonella Paratyphi A isolates were 99.2 % sensitive to ampicillin and 100 % sensitive to cotrimoxazole and ceftriaxone and 96.9 % sensitive to chloramphenicol and only 14.5 % sensitive to ciprofloxacin.Conclusion: The present study confers Salmonella Paratyphi A as the rapidly emerging pathogen of enteric fever. The antibiogram of Salmonella Typhi and Salmonella Paratyphi A showed decreased susceptibility to fluoroquinolones and a notable decrease in the multi drug resistant strains of Salmonella isolates with re-emergence of susceptibility to first line antibiotics.

Recent Progress in the Diagnosis of Pathogenic Candida Species in Blood Culture.

Candidemia has become an emerging invasive fungal disease. Prompt treatment with appropriate antifungal agent is crucial to reduce the mortality of candidemia. The conventional blood culture method, which is considered the gold standard for candidemia diagnosis, has a low sensitivity and is time-consuming to perform. Recently, several novel advanced diagnostic methods that have a higher sensitivity and a shorter turnaround time than the conventional blood culture method have been developed for the early detection of Candida in blood samples or in blood culture broth. Most of these newer methods were developed using various molecular techniques, such as matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, peptide nucleic acid fluorescence in situ hybridization, and a number of DNA-based techniques including in-house and commercial polymerase chain reactions. In this article, we review and summarize the novel molecular methods that have been recently used for the detection and identification of Candida organisms in blood specimens.

The Clinical Significance of Detecting Bacterial DNA by in situ Hybridization Method in Patients With Decompensated Liver Cirrhosis

Introduction: Patients with decompensated cirrhosis often suffer from various complications such as spontaneous bacterial peritonitis (SBP). However, it is difficult to diagnose SBP or bacteremia because bacteria in ascites or blood cannot be detected accurately by conventional culture method. It has been showed that the method using in situ hybridization (ISH) for detecting the gene of bacteria phagocytized by neutrophil in ascites is possibly useful to diagnose SBP within one day (Enomoto et al. J Hepatology 2012). It is thought that SBP is developed following bacteremia after bacterial translocation from the intestinal tract. Therefore we used the ISH method for blood samples taken from patients with decompensated liver cirrhosis and evaluated the significance of bacterial detection. Methods: Samples of peripheral blood and ascites were collected from 35 patients with ascites caused by liver cirrhosis. Blood samples were examined for bacteria using both conventional blood culture and ISH method. Samples of ascites were also evaluated by conventional culture simultaneously. The ISH method we used was the kit from Fuso Pharmaceuticals (Tokyo, Japan). Results: Eight of 35 patients were diagnosed with SBP. Six of the 8 patients showed positive results using the ISH method while bacteria were detected inonly one case byblood culture and one case by ascites culture. In 27 patients without SBP, 15 patients showed positive results using the ISH method while bacteria were detected in 4 cases by blood culture. The differences between 21 positive and 14 negative results by the ISH method were significant in presence of fever (16 / 5, p < 0.05) and decreased serum albumin levels (2.3 / 2.7, p < 0.05). However, there was no significant difference between administration of antibiotics, C-reaction protein level, and the presence of hepatocellular carcinoma. Notably, no patient who had a positive blood culture had a negative ISH result. Conclusion: The ISH method resulted in a higher positive rate of bacterial detection than culture in patients with decompensated cirrhosis. These results might implicate that “bacterial translocation,” which cannot be proved by conventional culture methods, really occurs. Therefore, it would be better for these patients with positive ISH results to be treated immediately. In patients with decompensated cirrhosis, the ISH method can be helpful for rapid diagnosis and early management of bacteremia and SBP.

Comparison of BacT/Alert microbial detection system with conventional blood culture method in neonatal sepsis

Blood culture remains the gold standard for diagnosing neonatal septicemia. Although automated continuous monitor- ing blood culture systems have generally been shown to be superior to conventional manual systems, there are few data relating to their use specifically in neonates. The aim of this study was to compare the manual method of blood culture with an automated BacT/Alert 3D system for detection of neonatal septicemia in terms of rate of recovery of pathogens and time to positivity. One hundred and one matched pairs of blood culture specimens from patients on a neonatal intensive care unit were evaluated by the two methods. The yield of significant pathogens with the BacT/Alert 3D system was 45.5%, compared with 18.8% with the manual method ( P< 0.0001). Moreover, streptococci, which are important neonatal pathogens, were detected exclusively with the automated system. The median time to positivity with the automated system was 11.5 h, compared with 24 h for the manual system. The BacT/Alert 3D system offers more sensitive and rapid detection of neonatal septicemia than a manual blood culture method. The clinical benefits of this may justify the additional cost of automated blood culture systems in developing countries where manual systems currently remain commonplace.

Trends in antimicrobial susceptibility of Salmonella Typhi from North India (2001-2012)

Purpose: Enteric fever is endemic in India with Salmonella Typhi being the major causative agent. Antibiotic therapy constitutes the mainstay of management. The present study was undertaken to find the susceptibility profile of Salmonella enterica var Typhi (S. Typhi) blood isolates in a tertiary care hospital between January 2001 and December 2012. Materials and Methods: A retrospective analysis of laboratory records was carried out. Conventional blood culture method was used until 2009; from January 2010 onwards BACTEC 9240 system has been in use. Salmonella were confirmed by serotyping using group and type specific antisera. Antibiotic susceptibility was performed using the disk diffusion method. In addition 116 isolates were subjected to minimum inhibitory concentration testing for chloramphenicol, ciprofloxacin, amoxicillin and nalidixic acid (NA) using agar dilution and for ceftriaxone and azithromycin using E-strips (Biomerieux). Result: A total of 1016 typhoidal salmonellae were obtained. The predominant serotype obtained was S. Typhi (852, 83.8%) followed by Salmonella enterica var Paratyphi A (164, 16.2%). We observed a re-emergence of susceptibility to first line antibiotics and a notable decline in multidrug resistant (MDR) strains. We also found all recent isolates resistant to NA and susceptible to third generation cephalosporins and 84.5% of isolates having decreasing ciprofloxacin susceptibility using revised criteria as per Clinical and Laboratory Standards Institute 2012 guidelines. Conclusion: There has been re-emergence of susceptibility to first line antibiotics and a notable decline in MDR strains of S. Typhi. We have a very high resistance to NA and decreasing susceptibility to ciprofloxacin. Third generation cephalosporins and azithromycin seem to be effective therapeutic options. Judicious use of these antibiotics is mandatory to prevent emergence of resistant strains.

Verigene® Gram-Positive Blood Culture Nucleic Acid Test

Bloodstream infections (BSIs) are a major cause of morbidity and mortality worldwide, and impose considerable costs on healthcare systems. A key predictor of clinical outcomes in patients with BSIs is the early initiation of appropriate targeted antimicrobial therapy. However, with conventional blood culture methods, the gold standard, there is a significant time delay of approximately 2-3 days before clinical results are available, with many patients receiving inappropriate and/or unnecessary antimicrobial therapy in the interim. During the past two decades, the use of in vitro assays that utilize nucleic acid amplification-based detection of pathogen-associated molecular patterns has led to a significant reduction in the time (hours vs. days with blood culture) to detection and identification of several of the causative pathogens of BSIs and, potentially, earlier initiation of targeted antimicrobial therapy. This review focuses on the properties and clinical use of one of these molecular diagnostic assays, the Verigene(®) Gram-Positive Blood Culture Nucleic Acid Test (BC-GP), which detects many of the potentially pathogenic Gram-positive bacteria associated with BSIs, including Staphylococcus spp., Streptococcus spp., Listeria spp., and Enterococcus spp., and specific resistance markers (mecA, vanA, and vanB). Based on more than 1,600 samples, there was a high degree of agreement between BC-GP test results and those obtained using conventional blood culture and assay methods, irrespective of whether samples were fresh or frozen, and a high degree of agreement for identification of mecA-mediated meticillin resistance in S. aureus and S. epidermidis organisms and vanA- or vanB-mediated vancomycin resistance in E. faecalis and E. faecium organisms.

Comparison of the Lysis Centrifugation Method with the Conventional Blood Culture Method in Cases of Sepsis in a Tertiary Care Hospital

Introduction:Physicians and microbiologists have long recognized that the presence of living microorganisms in the blood of a patient carries with it considerable morbidity and mortality. Hence, blood cultures have become critically important and frequently performed test in clinical microbiology laboratories for diagnosis of sepsis.Objectives:To compare the conventional blood culture method with the lysis centrifugation method in cases of sepsis.Materials and Methods:Two hundred nonduplicate blood cultures from cases of sepsis were analyzed using two blood culture methods concurrently for recovery of bacteria from patients diagnosed clinically with sepsis – the conventional blood culture method using trypticase soy broth and the lysis centrifugation method using saponin by centrifuging at 3000 g for 30 minutes.Results:Overall bacteria recovered from 200 blood cultures were 17.5%. The conventional blood culture method had a higher yield of organisms, especially Gram positive cocci. The lysis centrifugation method was comparable with the former method with respect to Gram negative bacilli. The sensitivity of lysis centrifugation method in comparison to conventional blood culture method was 49.75% in this study, specificity was 98.21% and diagnostic accuracy was 89.5%. In almost every instance, the time required for detection of the growth was earlier by lysis centrifugation method, which was statistically significant. Contamination by lysis centrifugation was minimal, while that by conventional method was high. Time to growth by the lysis centrifugation method was highly significant (P value 0.000) as compared to time to growth by the conventional blood culture method.Conclusion:For the diagnosis of sepsis, combination of the lysis centrifugation method and the conventional blood culture method with trypticase soy broth or biphasic media is advocable, in order to achieve faster recovery and a better yield of microorganisms.

Diagnosis of Systemic Fungal Infection by Polymerase Chain Reaction Versus Conventional Blood Culture Method in Patients of Oncology Center Mansoura University

Diagnosis of Systemic Fungal Infection by Polymerase Chain Reaction Versus Conventional Blood Culture Method in Patients of Oncology Center Mansoura University

Post-natal CMV infection via mother's milk in ELBW infants born to CMV seropositive mothers

s for 2nd International Conference on Clinical Neonatology Comparison of conventional blood culture method and BacT/Alert system with respect to yield and time to positivity in neonatal sepsis Arti Maria⁎, Sumitha Phalgun, Charoo Hans, N. Dubey, Deepak Goyal PGIMER & Associated Dr RML Hospital, New Delhi, India ⁎Corresponding author. Efficient and faster ways of diagnosing neonatal sepsis than conventional blood culture are needed in clinical practice. Recently, automated systems have been developed to address this issue. We hypothesized that automated compared to conventional methods of blood culture may give better isolation performances and shorter time to yield in the diagnosis of neonatal sepsis. This was a single-center, prospective, cohort study enrolling neonates with suspected neonatal sepsis in tertiary neonatal referral unit of north India. From May 2008 to April 2009, ninety consecutive neonates with suspected sepsis were enrolled with the objective of comparing the sensitivity and the time needed to yield positivity of conventional vs. BacT/Alert blood culture. Conventional and automated cultureswere collected in standardized manner from each baby, the order being alternate in consecutive babies. Refusal to consent, being ELBW and showing hemodynamical unstability were the only exclusion criteria for the neonates screened for inclusion in the study. Statistical analysis was conducted with the SPSS software version 11.0. The results showed that positivity by BacT/Alert was 38.8% (35/90) compared to 14.4% (13/90)with conventionalmethod (p<0.05). BacT/ Alert detected 30% isolates as early as within 12 h and 100% by 48 h whereas conventional detected none before 48 h and 69.2% by 72 h (p<0.001). Staphylococcus aureus was the commonest isolated microorganism (40% of cases). We concluded that a greater yield and earlier detection of pathogens by the Bact/Alert system make it more suitable for early definitive diagnosis of neonatal sepsis. This has implications for timely rational antibiotic therapy with possible favourable outcomes in neonatal sepsis. doi:10.1016/j.earlhumdev.2010.12.021 Safety of aqueous chlorhexidine gluconate for skin antisepsis in VLBW infants Maria Grazia Capretti⁎, Marica Spinelli, Elisabetta Tridapalli, Santo Arcuri, Anna Malavolti, Emanuela Callea, Giacomo Faldella Neonatal Intensive Care Unit, St. Orsola-Malpighi General Hospital, University of Bologna, Bologna, Italy Infection Control Unit, St. Orsola-Malpighi General Hospital, University of Bologna, Bologna, Italy ⁎Corresponding author. No guidelines are available for antisepsis in infants with age <2 months. The aim of this study is to evaluate the efficacy and safety of aqueous chlorhexidine gluconate (aCG) at different concentrations for skin disinfection in VLBW (birth weight <1500 g) infants. Two different protocols for skin antisepsis were prospectively used. The rate of nosocomial infection and adverse effects were compared. In the first period (January 2007 to December 2008) we used 2%aCG solution, regardless of gestational age (GA) and birth weight (BW); in the second period (January 2009 to October 2010) 0.1%aCG was used in the first ten days of life in newborns with GA=27 weeks and/or BW=750 g and 1%aCG, in the remaining cases. Microbiological culture of CVC-tips, blood samples, urine and respiratory tract specimens were collected when infection was suspected. First period infants 15/124 vs second period infants 14/103 were found infected after 72 h of life (p=0.842); among infants with BW<750 g, 9/31were infected in the first period vs 3/21 in the second period (p=0.318). Five ELBW infants (BW<1000 g) showed burns using 2%aCG prior to insertion of umbilical venous or peripherally inserted central catheters. No burns or other adverse events were observed in the second period. Our data show that 2%aCG may not be safe when used in ELBW infants in the first days of life, suggesting that antisepsis solution in premature should be differentiated according to GA and chronologic age. doi:10.1016/j.earlhumdev.2010.12.022 Post-natal CMV infection via mother's milk in ELBW infants born to CMV seropositive mothers

Comparison of conventional blood culture method and BacT/Alert system with respect to yield and time to positivity in neonatal sepsis

s for 2nd International Conference on Clinical Neonatology Comparison of conventional blood culture method and BacT/Alert system with respect to yield and time to positivity in neonatal sepsis Arti Maria⁎, Sumitha Phalgun, Charoo Hans, N. Dubey, Deepak Goyal PGIMER & Associated Dr RML Hospital, New Delhi, India ⁎Corresponding author. Efficient and faster ways of diagnosing neonatal sepsis than conventional blood culture are needed in clinical practice. Recently, automated systems have been developed to address this issue. We hypothesized that automated compared to conventional methods of blood culture may give better isolation performances and shorter time to yield in the diagnosis of neonatal sepsis. This was a single-center, prospective, cohort study enrolling neonates with suspected neonatal sepsis in tertiary neonatal referral unit of north India. From May 2008 to April 2009, ninety consecutive neonates with suspected sepsis were enrolled with the objective of comparing the sensitivity and the time needed to yield positivity of conventional vs. BacT/Alert blood culture. Conventional and automated cultureswere collected in standardized manner from each baby, the order being alternate in consecutive babies. Refusal to consent, being ELBW and showing hemodynamical unstability were the only exclusion criteria for the neonates screened for inclusion in the study. Statistical analysis was conducted with the SPSS software version 11.0. The results showed that positivity by BacT/Alert was 38.8% (35/90) compared to 14.4% (13/90)with conventionalmethod (p<0.05). BacT/ Alert detected 30% isolates as early as within 12 h and 100% by 48 h whereas conventional detected none before 48 h and 69.2% by 72 h (p<0.001). Staphylococcus aureus was the commonest isolated microorganism (40% of cases). We concluded that a greater yield and earlier detection of pathogens by the Bact/Alert system make it more suitable for early definitive diagnosis of neonatal sepsis. This has implications for timely rational antibiotic therapy with possible favourable outcomes in neonatal sepsis. doi:10.1016/j.earlhumdev.2010.12.021 Safety of aqueous chlorhexidine gluconate for skin antisepsis in VLBW infants Maria Grazia Capretti⁎, Marica Spinelli, Elisabetta Tridapalli, Santo Arcuri, Anna Malavolti, Emanuela Callea, Giacomo Faldella Neonatal Intensive Care Unit, St. Orsola-Malpighi General Hospital, University of Bologna, Bologna, Italy Infection Control Unit, St. Orsola-Malpighi General Hospital, University of Bologna, Bologna, Italy ⁎Corresponding author. No guidelines are available for antisepsis in infants with age <2 months. The aim of this study is to evaluate the efficacy and safety of aqueous chlorhexidine gluconate (aCG) at different concentrations for skin disinfection in VLBW (birth weight <1500 g) infants. Two different protocols for skin antisepsis were prospectively used. The rate of nosocomial infection and adverse effects were compared. In the first period (January 2007 to December 2008) we used 2%aCG solution, regardless of gestational age (GA) and birth weight (BW); in the second period (January 2009 to October 2010) 0.1%aCG was used in the first ten days of life in newborns with GA=27 weeks and/or BW=750 g and 1%aCG, in the remaining cases. Microbiological culture of CVC-tips, blood samples, urine and respiratory tract specimens were collected when infection was suspected. First period infants 15/124 vs second period infants 14/103 were found infected after 72 h of life (p=0.842); among infants with BW<750 g, 9/31were infected in the first period vs 3/21 in the second period (p=0.318). Five ELBW infants (BW<1000 g) showed burns using 2%aCG prior to insertion of umbilical venous or peripherally inserted central catheters. No burns or other adverse events were observed in the second period. Our data show that 2%aCG may not be safe when used in ELBW infants in the first days of life, suggesting that antisepsis solution in premature should be differentiated according to GA and chronologic age. doi:10.1016/j.earlhumdev.2010.12.022 Post-natal CMV infection via mother's milk in ELBW infants born to CMV seropositive mothers

Comparison of Different PCR Methods for Detection of Brucella spp. in Human Blood Samples

For detection of Brucella species by PCR four DNA extraction methods and four targets were compared using pure culture of Brucella melitensis and the best conditions were applied in clinical samples. It was found that the MagNA Pure LC method was the most efficient and sensitive method showing a positive PCR reaction with DNA extracted from as low as 25 and 100 CFU suspended in one ml blood and one ml water, respectively. Detection of Brucella spp. by conventional PCR was investigated using four different targets. The results indicated that The B4-B5 amplification method was the most sensitive one as it could amplify DNA extracted from as a low as 25 and 100 CFU/ml suspended in one ml water and blood, respectively. Furthermore real-time PCR was able to detect Brucella using DNA extracted from as low as 50 CFU/ml blood and 15 CFU/ml water, respectively. The best and optimum detection conditions were applied to the clinical samples. Evaluation of conventional PCR assays on blood specimens confirmed 72% of the results obtained by conventional blood culture methods with a specificity of 95%, while serum samples had a sensitivity of 54% and specificity of 100%. Real-time PCR was generally found to be more sensitive and specific for detecting Brucella spp. in blood and serum samples compared to conventional PCR. The real-time PCR done on blood specimens confirmed 77.5% of the results obtained by conventional blood culture methods with specificity of 100%, while 60% of serum samples were found to be positive with specificity of 100%. These results suggest that serum and blood analysis by conventional and real time PCR is a convenient and safe method for rapid and accurate diagnosis of brucellosis.