Pediatric Blood Culture Research Articles

Time to positivity of blood cultures in paediatric patients.

Continuous monitoring of blood culture (BC) systems allows rapid detection of microbial growth. We aimed to determine differences in time to positivity (TTP) in BACTEC BC between organisms and whether a 36-h period was sufficient to detect all relevant pathogenic bacteria for children admitted to a tertiary care paediatric hospital. This was a retrospective audit of positive aerobic (AE) and anaerobic (AN) BC from paediatric inpatients with available TTP from 1 August 2016 to 2 January 2019. First positive BC per bacteraemia episode was analysed. Overall, 649 BC were positive, of which 480 first positive BC were analysed: 246 AE (51.3%) only, 216 paired (45%) (108 AE and 108 AN) and 18 AN (3.8%) only. There were 372 episodes of bacteraemia in 340 patients. Median age was 19 months (interquartile range (IQR): 1.25-60). Median TTP for AE and AN cultures was 13.20 (IQR: 9.84-18.48) and 13.92 h (IQR: 10.32-17.04), respectively. Organisms were GNR 49.7%, GPC 29.6%, contaminants 14.5%, mixed 3.0%, other 2.4% and yeast 0.8%. Streptococcus agalactiae had the fastest median TTP in AE and AN cultures, followed by Escherichia coli (AE 8.88 vs. 10.20 h). For paired AE and AN cultures, TTP was faster for AE versus AN cultures (13.36 vs. 14.52 h, P = 0.001). A 36-h cut-off time captured 97.7% AE BC and 99.1% AN BC with pathogens, and 86.5% AE BC and 91.7% AN BC with contaminants, respectively. GNR were the commonest pathogens in paediatric BC and faster growth was detected in AE versus AN cultures. By 36 h, >97.7% of BC were positive for pathogens versus 86.5% for contaminants.

Evaluation of Direct Antimicrobial Susceptibility Testing of Gram-Negative Bacilli and Staphylococcus aureus from Positive Pediatric Blood Culture Bottles Using BD Phoenix M50.

Bloodstream infections (BSIs) are life-threatening infections for which a timely initiation of appropriate antimicrobial therapy is critical. Antibiotic susceptibility testing (AST) directly performed on positive blood culture broths can help initiate targeted antibiotic therapy sooner than the standard AST performed on colonies isolated on solid media after overnight incubation. Faster antimicrobial susceptibility testing (AST) results can improve clinical outcomes, and reduce broad-spectrum antimicrobial consumption and healthcare-associated costs in sepsis. In this study, we evaluated the accuracy of a direct AST inoculation method on the BD Phoenix M50 system using serum separator tubes to harvest bacteria from positive pediatric blood culture bottles. Direct AST was performed on 132 monomicrobial pediatric blood culture bottles that were positive for Enterobacterales (65; 49.2%), Staphylococcus aureus (46; 34.8%), and non-fermenting Gram-negative bacilli (21; 16%). Overall, the categorical and essential agreements between the direct method and standard method were 99.6% and 99.8%, respectively. Very major, major, and minor error rates were 0.1%, 0.09%, and 0.20% respectively. Direct AST performed on pediatric blood culture bottles using BD Phoenix M50 can quickly provide accurate susceptibility information to guide antimicrobial therapy in patients with BSI.

Coagulase-negative Staphylococci – A True Pathogen in Bloodstream Infections and their Resistance Patterns in a Tertiary Care Hospital

Coagulase-negative staphylococci (CoNS) are primary skin commensals that have long been considered contaminants even when grown in blood cultures. This group of organisms has been recently recognized as a potential causative pathogen of septicemia. This increase has been attributed to the increased use of intravascular and prosthetic devices. Hence, we aimed to estimate the prevalence of CoNS as a true pathogen in adult and pediatric blood cultures along with their antibiotic susceptibility patterns. A total of 1076 adult and 611 pediatric blood cultures were subjected to an automated BacT/ALERT continuous monitoring system. Isolated CoNS were considered true pathogens if they met the diagnostic, clinical, and laboratory criteria. Antimicrobial susceptibility testing for pathogenic CoNS was carried out using the Kirby-Bauer disk diffusion method and interpreted as per CLSI 2021. CoNS were considered true pathogens in 23 (42.5%) of 54 adults and 12 (41.3%) of 29 pediatric CoNS isolated from blood cultures. Methicillin-resistant CoNS was detected in 66% and 70% of adult and pediatric cultures, respectively. All the CoNS isolates were sensitive to vancomycin and linezolid. Coagulase-negative staphylococci (CoNS) can either be a contaminant or a true pathogen, whose discrimination based on clinical and laboratory indices plays a pivotal role in the management of patients with sepsis.

Prevalence and Pattern of Antibiotic Susceptibility of Gram-Negative Bacteria Isolated from Pediatric Blood Culture

It was aimed to evaluate the antibiotic susceptibilities of Gram-negative bacteria isolated from blood samples taken from pediatric patients. The samples were evaluated with the Bactec 9120 automation system bacteria were identified by the Gram-Negative ID panel using the Vitek 2 Compact (Biomerieux France) device performed with the AST N090 panel, and the results were evaluated according to The Clinical and Laboratory Standards Institute (CLSI) recommendations. Antibiotic resistance results: Ceftriaxone was the most resistant antibiotic (71.4%). Salmonella spp. it was mostly resistant to levofloxacin and ciprofloxacin (100%). While E. coli strains were the most resistant to ticarcillin and piperacillin (71.4%), the most effective antibiotics against this bacterium were imipenem and meropenem (100%). Resistance rates to all tested antibiotics were significantly higher in ESBL-producing Klebsiella spp and E coli strains than in non-ESBL-producing strains (p

Pediatric blood cultures—turning up the volume: a before and after intervention study

The major determinant of blood culture (BC) diagnostic performance is blood volume, and pediatric sample volumes are frequently low. We aimed to assess BC volumes in our institution, design an intervention to increase volumes, and assess its impact. All pediatric BCs submitted over a 7-month period to the microbiology laboratory in a university hospital (including emergency department, pediatric ward, and neonatal unit) were included. A pre-intervention period assessed current practice. A multi-faceted intervention (education, guideline introduction, active feedback strategies) was collaboratively designed by all stakeholders. Impact was assessed in a post-intervention period. The main outcome measures included the percentage of samples adequately filled using three measures of sample adequacy (1) manufacturer-recommended minimum validated volume—> 0.5 ml, (2) manufacturer-recommended optimal minimum volume—> 1.0 ml, (3) newly introduced age-specific recommendations. Three hundred ninety-eight pre-intervention and 388 post-intervention samples were included. Initial volumes were low but increased significantly post-intervention (median 0.77 ml vs. 1.52 ml), with multivariable regression analysis estimating volumes increased 89% post-intervention. There were significant increases in all measures of volume adequacy, including an increase in age-appropriate filling (20.4–53.1%), with less improvement in those aged > 3 years. Overall, 68.4% of pathogens were from adequately filled cultures, while 76% of contaminants were from inadequately filled cultures. A pathogen was detected in a higher proportion of adequately filled than inadequately filled cultures (9.4% vs. 2.2%, p < 0.001). Conclusion: Blood volume impacts BC sensitivity, with lower volumes yielding fewer pathogens and more contaminants. Focused intervention can significantly improve volumes to improve diagnostic performance.What is Known:• Blood volume is the major determinant of blood culture positivity, and yet pediatric blood culture volumes are frequently low, resulting in missed pathogens and increased contamination.What is New:• Adequately filled (for age) blood cultures have a pathogen detection rate three times higher than inadequately filled blood cultures.• This interventional study shows that collaboratively designed multi-modal interventions including focus on accurate volume measurement can lead to significant increases in blood volumes and improve blood culture diagnostic performance.

Pitfalls of a Multiplex PCR Panel for Identification of Bloodstream Pathogens.

We evaluated the diagnostic performance of the FilmArray Blood Culture Identification Panel (BCID; bioMerieux) for the detection of bloodstream pathogens. From May to August 2022, up to 67 samples from positive blood cultures previously processed with BACTEC FX (BD) were collected and submitted to the BCID panel. BCID panel results were compared with traditional culture results. We tested 67 positive blood culture samples; 13 samples were from pediatric bottles of BACTEC Peds Plus/F media (BD). The overall sensitivity of the BCID panel was 89.9% (62/69; 95% CI, 80.2 - 95.3%). For blood-stream pathogens targeted by the BCID panel, sensitivity was 98.4% (62/63; 95% CI, 90.7 - > 99.9%). Interestingly, Proteus species were additionally detected in 6 samples from pediatric blood culture bottles. BCID demonstrated high clinical sensitivity for target pathogens, but positive findings for unexpected multiple targets or Proteus species require cautious interpretation to avoid false positives.

172. Impact of a quality improvement re-training program on the blood culture volume, yield and contamination rates; experience from South India

Abstract Background Blood cultures help to detect causative agents in bacteremia and are important for targeted therapy. Adequate blood culture volume is considered as 8-10ml in each bottle and at least 2 aerobic and 2 anaerobic blood culture bottles are recommended. Inadequate blood culture fills are common and may affect yield. Figure 1 Methods The study was done in our healthcare facility-KIMSHEALTH, Trivandrum, India. Pre-intervention period was between May 2021 and June 2021; post-intervention was between May 2022 and June 2022. The intervention was through plan/do/study/act (PDSA) cycles and included multiple training sessions to the phlebotomy team regarding adequate fill volume which is 8-10 ml in each blood culture bottle. Training for maintaining asepsis during collection was reinforced. All blood culture samples received in the hospital microbiology laboratory during the above period were included in this study and compared between the pre-intervention and post-intervention period. Pediatric blood culture samples were excluded. Results Blood culture samples studied during pre and post intervention period were 1428 and 1716 respectively. In the pre-intervention phase adequate fill volume was noted in 30.81% bottles (figure 1), while in the post intervention adequate fill volume was noted in 68.06% bottles (p &amp;lt; 0.01). Blood culture contamination rate was 3.01% in the pre-intervention period which improved to 2% in the post-intervention period and the difference was significant (p&amp;lt; 0.01). Blood culture yield of a pathogenic organism did not show significant difference after the intervention (11.2% in pre-intervention group Vs 11.45% in post intervention group). Conclusion In this study, an improvement was noted in the blood culture fills by 38% and contamination rate reduced by 1%. Though there was no significant increase in blood culture yield with intervention, the reduction in contamination was noted which will reduce unnecessary antibiotic initiation. Disclosures All Authors: No reported disclosures

P167 Fungemia in neonatal ICU of a pediatric hospital in NE India

Poster session 2, September 22, 2022, 12:30 PM - 1:30 PM ObjectivesTo determine the prevalence of fungemia in a neonatal intensive care unit (NICU) during a period of 4 years and 4 months (January 2018 to April 2022) and to identify the causative fungal pathogens and analyze the associated risk factors.MethodsA retrospective study was conducted by collecting records of neonatal fungemia occurring in 17 bedded NICU of Mother's Care Children Hospital and Research Centre, Imphal. Cases were identified by searching of computerized microbiology blood culture database. Blood cultures were carried out using automated BacT/ALERT(Biomerieux). Whenever flagged positive, immediate gram staining and subculture were carried in Blood agar, SDA, and MacConkey agar. The isolates were identified by their morphology, germ tube test, and biochemical test in VITEK-2 (Biomeriux) system. Antifungal susceptibility testing too was carried out in VITEK-2.ResultsA total of 2621 blood samples in pediatric blood culture bottles were received from NICU during this period of 4 years and 4 months. 21 samples showed growth of yeast cells. The isolates include Candida parapsilosis (10), C. albicans (7), Wickerhaemomyces anomalas (3), and C. krusei (1). Low birth weight, premature rupture of membrane, antibiotic therapy, and prolonged hospital stay were main risk factors. Majority of the neonates recovered with antifungal treatment.Conclusion Candida parapsilosis was isolated with highest frequency. Fungemia is more common in low birth weight babies.

Preterm Infant with Respiratory Distress, Hypotonia, and Hypoglycemia.

Preterm Infant with Respiratory Distress, Hypotonia, and Hypoglycemia.

Performance and Impact on Initial Antibiotic Choice of Direct Identification of Pathogens from Pediatric Blood Culture Bottles Using an In-House MALDI-TOF MS Protocol.

ABSTRACTThe performance and early therapeutic impact of direct identification by matrix-assisted laser desorption ionization–time-of-flight mass spectrometry (MALDI-TOF; DIMT) on pediatric blood culture bottles using in-house-developed methods to obtain microbial pellets for spectrometric analysis have seldom been studied. During a 2-year period (June 2018 to May 2020), DIMT was performed on broths from positive pediatric blood culture bottles using an in-house-developed method. Organism identifications with a score of ≥1.6 were notified to treating clinicians. Therapeutic modifications that occurred after the communication of DIMT were reviewed through the electronic medical records. DIMT was performed on 530 pediatric positive blood culture bottles. Among 505 monomicrobial bottles, identifications from 298 (97.7%) deemed as bloodstream infections (BSI) and 189 (94.5%) as contaminations had DIMT notified to clinicians. All identifications were correct except for one Streptococcus mitis incorrectly reported as Streptococcus pneumoniae. Therapy modifications resulting from DIMT occurred in 27 (8.3%) patients with BSI. Deescalation from effective or ineffective broad-spectrum regimens occurred mainly in Enterococcus faecalis bacteremia, whereas appropriate escalation from an ineffective regimen with narrower spectrum occurred mainly in bacteremia caused by AmpC-β-lactamase-producing Enterobacterales. Escalation therapy was instituted significantly faster than deescalation therapy (median time, 0.75 versus 10.5 h [P = 0.01]). DIMT also enabled clinicians to confirm contamination in nearly one-half of patients with contaminated blood cultures. Our DIMT method applied to positive pediatric blood culture bottles demonstrated reliable performance for the rapid identification of pathogens. Our DIMT approach allowed therapeutic optimization in BSI, especially involving microorganisms with intrinsic antibiotic resistance, and was helpful in the early identification of likely contaminants.IMPORTANCE We demonstrate the performance and early impact on the antimicrobial management of bloodstream infections of an inexpensive, in-house preparation method for direct identification of bloodstream pathogens in pediatric blood culture bottles by matrix-assisted laser desorption/ionization–time-of-flight mass spectrometry.

Improving empiric antibiotic prescribing in pediatric bloodstream infections: a potential application of weighted-incidence syndromic combination antibiograms (WISCA)

ABSTRACT Background: Increasing antibiotic resistance to WHO-recommended first- and second-line treatments of pediatric sepsis requires adaptation of prescribing guidelines. We discuss the potential and limitations of a weighted-incidence syndromic combination antibiogram (WISCA) as a practical tool for incorporating local microbiology data when assessing empiric coverage of commonly used antibiotics. Research design and methods: A brief questionnaire of 18 clinically significant isolates from pediatric blood cultures (Jan-Dec 2018) was sent to a global network of pediatric hospitals in July 2019. Weighted coverage estimates of non-antipseudomonal third-generation cephalosporins (3GC) and meropenem were estimated using Monte–Carlo simulation for each site reporting >100 isolates. Results: 52 hospitals in 23 countries in 5 WHO regions responded to the questionnaire; 13 sites met the sample size requirement. The most common isolates were S. aureus, Klebsiella spp., E. coli and Enterococcus spp. Coverage of 3GC ranged from 39% [95%CrI: 34–43%] to 73% (two sites: [95%CrI: 65–80%]; [95%CrI: 68–86%]) and meropenem coverage ranged from 54% [95%CrI: 47–60%] to 88% [95%CrI:84–91%]. Conclusions: A WISCA is a data-driven, clinically intuitive tool that can be used to compare empiric antibiotic regimens for pediatric sepsis using existing large datasets. The estimates can be further refined using more complex meta-analytical methods and patient characteristics.

Diagnostic Value of Multiplex Polymerase Chain Reaction in Detection of Acinetobacter baumannii, Pseudomonas aeruginosa, and Stenotrophomonas maltophilia from Sepsis in Pediatrics.

Proper identification of the causative organism in pediatric sepsis is crucial for early diagnosis and prevention of septic shock and organ failure. The aim of the present study was to evaluate the multiplex polymerase chain reaction (PCR) for detection of Acinetobacter baumannii, Pseudomonas aeruginosa, and Stenotrophomonas maltophilia from positive blood cultures for these pathogens isolated from children with hospital- acquired sepsis compared to the conventional biochemical reactions for identification of these organisms. This study was a cross-sectional study performed on 100 isolates from pediatric blood cultures, including Acinetobacter baumannii, Pseudomonas aeruginosa, and Stenotrophomonas maltophilia. The study also included 100 isolates of Escherichia coli as a negative control. All isolates were identified by API 20NE and the multiplex PCR with primers specific to the 3 tested bacteria. Multiplex PCR was positive in 96% of isolates and 4 isolates had negative results. Falsepositive results were reported with three E. coli strains. Multiplex PCR identified all the isolates of Acinetobacter baumannii, 29 isolates of Pseudomonas aeruginosa and 27 isolates of Stenotrophomonas maltophilia. The diagnostic value of the multiplex PCR compared to the biochemical identification revealed sensitivity 96.04%, specificity 96.9%, positive predictive value 97.00%, negative predictive value 96.00% and accuracy 96.50%. The present study highlights the diagnostic value of multiplex PCR to identify Acinetobacter baumannii, Pseudomonas aeruginosa, and Stenotrophomonas maltophilia from positive blood cultures. Multiplex PCR was sensitive, specific and accurate. The accuracy differs according to the organisms with 100% accuracy for Acinetobacter baumannii.

Antimicrobial Resistance Trends at a Pediatric Hospital in Guatemala City, 2005-2019.

Antimicrobial resistance (AMR) is increasing worldwide. We analyzed AMR rates for bacterial species identified from pediatric blood cultures between 2005 and 2019 at a single institution in Guatemala. We found significantly increased rates in Gram-negative resistance, with a high prevalence of carbapenem-resistant Acinetobacter and Klebsiella harboring the New Delhi metallo-beta-lactamase gene.

Management of Pediatric Nonpathogenic Blood Cultures After Introduction of PCR Technology.

The rapid identification of organisms reported in positive blood cultures via polymerase chain reaction (PCR) can accurately identify a nonpathogenic bacterium and decrease time to definitive identification, as compared with traditional microbiologic methods. How this technology effects clinical and antimicrobial management in children with nonpathogenic bacteria identified in a blood culture without decision support has not been evaluated. A retrospective study of the management of children with positive blood culture results for nonpathogenic organisms before and after implementation of PCR technology. Each cohort's antibiotic management, frequency of repeat cultures, and return visits to an emergency department (ED) were compared. A total 136 patients during this time (49% [n = 67] pre-PCR and 51% [n = 69] post-PCR) had a blood culture positive for nonpathogenic bacterium. Admitted patients had a second specimen sent for testing on fewer occasions (P = .04); however, total antibiotic exposure did not differ significantly (P = .3) after introduction of PCR technology. There was no significant difference in length of stay postintervention (P = .12). Patients discharged directly from the ED had fewer return visits (P = .02) and received fewer repeat blood cultures (P = .04), and antibiotics were administered on fewer occasions after return (P = .04) postintroduction of PCR technology. With the addition of PCR technology, patients with blood cultures positive for nonpathogenic bacteria received less antibiotics, fewer repeat blood cultures, and fewer repeat ED evaluations.

Comparison of Microorganism Detection and Time to Positivity in Pediatric and Standard Media from Three Major Commercial Continuously Monitored Blood Culture Systems.

New blood culture instrumentation and medium formulations have led to improved time to positivity (TTP) for positive blood cultures. Data regarding the necessity of pediatric blood culture bottles with contemporary blood culture systems are sparse. We compared performance of three commercial blood culture systems, evaluating impact of blood volumes in standard and pediatric blood culture media across systems. Simulated blood cultures with packed red blood cells (PRBCs) and three Gram-positive, four Gram-negative, and one anaerobic organism (final concentrations ranging from 0.5 to 19 CFU/ml blood) on the Virtuo, VersaTrek, and Bactec FX instruments were evaluated with FAN Plus, Redox, and Bactec Plus media, respectively. For each medium/instrument/organism combination, 1-, 3-, 5-, and 10-ml blood volumes were evaluated in triplicate. Detection rate was not affected by blood volume. Aerobic organisms that demonstrated variable rates of detection were Kingella kingae, Haemophilus influenzae, and Neisseria meningitidis. Bacteroides fragilis was detected in 83%, 100%, and 100% of Virtuo, VersaTrek, and Bactec anaerobic bottles, respectively. The average TTP of standard medium for aerobic organisms detected on Virtuo was decreased compared to those for VersaTrek (-2.3 h) and Bactec (-4.9 h). Compared to standard medium, detection rate and TTP were unchanged on Virtuo, while TTP was reduced with pediatric medium for 2/8 organisms tested on Bactec and 7/8 organisms on VersaTrek, illustrating the potential benefit of pediatric medium on VersaTrek or Bactec when low blood volumes (<5 ml) are collected. These results demonstrate that TTP is decreased on the Virtuo compared to VersaTrek and Bactec for many microorganisms associated with bloodstream infection (BSI) but may have species-specific limitations.

Lack of Detection of Haemophilus influenzae Using Adult Blood Culture Bottles Inoculated at Low Volumes.

Based on guidelines from the Infectious Diseases Society of America and the American Society for Microbiology, many pediatric hospitals are implementing weight-based collection guidelines for blood cultures. To simplify the process of culture collection, there has been interest in validating the use of adult blood culture bottles with low volumes, which may allow for a "one size fits all" bottle. This study examined 9 clinically relevant organisms (Staphylococcus aureus, Streptococcus pneumonia, Streptococcus agalactiae, Enterococcus faecium, Escherichia coli, Haemophilus influenzae, Pseudomonas aeruginosa, Candida glabrata, and Candida albicans) utilizing the BD BacTec system at various inoculation volumes and dilutions to assess performance, based on time to positivity, of adult blood culture bottles compared with pediatric blood culture bottles. There was a lack of detection of H. influenzae using adult blood culture bottles inoculated at low volumes, whereas pediatric bottles detected H. influenzae regardless of dilution-volume combinations tested. Exclusive use of adult blood culture bottles may not detect H. influenzae bacteremia in the setting of low-volume inoculum.

Simulated Pediatric Blood Cultures to Assess the Inactivation of Clinically Relevant Antimicrobial Drug Concentrations in Resin-Containing Bottles.

The bacteremia level as well as the administration of antibiotics before blood collection may significantly affect the recovery of bacterial pathogens from pediatric blood cultures in BacT/Alert Virtuo or Bactec FX BC systems, which remain the common techniques to diagnose bacteremia in pediatric patients. We simulated pediatric blood cultures with low or intermediate bacteremia level to evaluate BacT/Alert PF Plus and Bactec Peds Plus blood culture bottles for resin-based inactivation of 16 antibiotic–bacterium combinations. Overall, 105/192 (54.7%) of BacT/Alert PF Plus bottles and 69/192 (36.0%) of Bactec Peds Plus bottles allowed organisms to grow when exposed to antibiotics. In particular, both BacT/Alert PF Plus and Bactec Peds Plus bottles proved to be effective with piperacillin/tazobactam and Pseudomonas aeruginosa or with oxacillin and methicillin-susceptible Staphylococcus aureus (100% growth), whereas no effectiveness was apparent with ceftriaxone and Escherichia coli, Streptococcus agalactiae, or Streptococcus pneumoniae or with cefepime and E. coli (0% growth). In some relevant instances (e.g., with vancomycin and methicillin-resistant S. aureus or Streptococcus pneumoniae), BacT/Alert PF Plus bottles were superior to Bactec Peds Plus bottles. Together, these findings underscore the potentiality of resin-containing bottles to enhance diagnosis of bacteremia in pediatric patients on antimicrobial therapy. This is particularly true with one of the evaluated BC systems and with simulated intermediate bacteremia level only.

97. Assessment of the accuracy of direct antimicrobial susceptibility testing from positive blood cultures in pediatric patients and its utility as an antimicrobial stewardship tool

BackgroundHospitalized pediatric patients with bacteremia receive broad-spectrum antibiotics while organism identification and antibiotic susceptibilities are pending. Direct susceptibility testing (DST) using unstandardized Kirby-Bauer disk diffusion provides early results before standardized (final) antimicrobial susceptibility testing (AST) is available. The accuracy of DST in comparison with AST has been poorly studied. If DST is highly accurate, it could facilitate earlier de-escalation of antibiotics.MethodsRetrospective cohort study of all positive blood cultures at Boston Children’s Hospital between January 1, 2017 and October 20, 2019. Isolates were eligible for inclusion if a DST result was available. Isolates were excluded if more than one organism grew from a blood culture or if a patient had repeat blood cultures positive for the same organism within 14 days. Patient characteristics and antibiotic orders were identified via a local data warehouse. Positive and negative predictive value (PPV: accuracy of susceptibility on DST in identifying susceptibility on AST result; NPV: accuracy of DST in identifying non-susceptibility on AST result) and 95% confidence interval were calculated for each bug-drug combination. Antibiotic Spectrum Index was evaluated at 3 time points to assess change in antibiotic prescribing after availability of DST and AST results.Results496 patients (median age: 51 months, IQR: 7–165 months) with 603 positive blood cultures were included in the final analysis. PPV of DST was ≥96%for most organism-antibiotic pairs (Table). NPV of DST varied substantially across organism-antibiotic pairs and was frequently lower than PPV. The proportion of patients with more narrow spectrum antibiotic orders increased after the DST result and again after the AST result (Figure).TableTest performance of direct susceptibility testing (DST) of clinical isolates from patients with bacteremia to identify organism susceptibility to the noted antibiotic. Positive predictive value measures the ability of a susceptible DST result to predict a susceptible AST result. Negative predict value measures the ability of an intermediate or resistant DST result to predict an intermediate or resistant AST result. *Includes Staphylococcus capitis, Staphylococcus epidermidis, Staphylococcus haemolyticus, Staphylococcus hominis, Staphylococcus pettenkoferi, and Staphylococcus warneri. ‡Includes Citrobacter freundii complex, Citrobacter koseri, Enterobacter aerogenes, Enterobacter cloacae complex, Escherichia coli, Escherichia vulneris, Klebsiella oxytoca, Klebseilla pneumoniae, Klebsiella variicola, Pantoea species, Proteus mirabilis, Salmonella species, Salmonella typhi, Serratia liquefaciens, and Serratia marcescens. FigureDistribution of spectrum of antibiotics ordered to treat bacteremia in pediatric patients. Antibiotic spectrum, as measured by the antibiotic spectrum index, is represented in this Sankey diagram on the Y-axis. The height of each group indicates the proportion of patients with an aggregate antibiotic spectrum falling in that category at three time points. The ASI of empiric antibiotics was measured just before the DST result to provide time for a treating physician to settle on an empiric regimen. The ASI with the DST result was measured just before the ASI result. The ASI with the AST result was measured 24 hours after the AST result was available. Green bars indicate the proportion of patients within a group whose ASI remained unchanged between time points. Blue bars indicate the proportion of patients within a group whose ASI decreased, and red bars indicate the proportion of patients whose ASI increased between time points. ConclusionDST is highly accurate at identifying susceptibility to antibiotics for many bug-drug combinations in pediatric blood culture isolates, but its ability to identify non-susceptibility is less robust. The observed spectrum of prescribed antibiotics was narrower after DST results, suggesting some clinicians may be using the result to de-escalate therapy. DST may be a useful low-cost tool for antimicrobial stewardship.Disclosures All Authors: No reported disclosures

First comprehensive study on neonatal septicaemia at secondary-level public health-care facilities in Central India: An eye opener

Background: In India secondary-level public health-care facilities (HCF)-District Hospitals, are not equipped either with a microbiological laboratory or a robust Infection control program. The present study was initiated to investigate the epidemiology of neonatal septicaemia in SNCUs (Special new-born care units) situated at various District Hospitals of Chhattisgarh (a state in Central India) in terms of Blood Stream Infection (BSI) rates, pathogen profile and their antimicrobial sensitivity patterns. Methods & Materials: The study was conducted from October 2017 through June 2019 at the Department of Microbiology, All India Institute of Medical Sciences (AIIMS), Raipur, a tertiary level healthcare teaching institute in collaboration with 23 SNCUs. Paired blood samples (0.5–1.0 ml) were collected in paediatric aerobic blood culture bottles (BacT/ALERT PF Plus, BioMerieux Inc. Durham, NC, USA) and transported to the laboratory, where culture and identification was performed by automated ID and AST system (Vitek 2 ID/AST system, BioMerieux Inc. Durham, USA) and by manual methods using standard laboratory protocol. Results: Paired blood cultures were received from 2843 neonates; out of which 1645 (58%) were sterile, 388 (13.6%) grew contaminants and 810 grew pathogens, indicating BSI rate of 28.4%. Gram negative bacilli were the most commonly encountered pathogens (382/810, 47.2%), with more than half being multi drug resistant (211/382, 55.2%). Klebsiella pneumoniae was the commonest isolate (n = 253). Amongst the gram- positive cocci (253/810, 31.2%) coagulase negative staphylococcus (CoNS) was commonest. Only 17 (6.7%) Methicillin Resistant Staphylococcus aureus and one Streptococcus agalactiae were isolated. Candida spp. accounted for 21.6% (175/810) pathogen, predominated by non-albicans candida (161/175). 18% of the Candida spp. were resistant to Fluconazole, while 1.2% were MDR. A fall in NMR (neonatal mortality rate) and antibiotic usage rate was observed in almost all the units after the microbiology laboratory support was initiated. Conclusion: The secondary-level public health-care facilities have a very high rate of laboratory proven neonatal septicemia with an alarmingly high AMR (Antimicrobial resistance) rate, both among bacterial and fungal isolates. This warrants urgent intervention for reducing neonatal septicaemia by microbiology laboratory support, optimising infection control practices and implementing AMSP (antimicrobial stewardship program).

Isolation of clinically significant microorganisms from prosthetic joint tissue using BacT/ALERT paediatric blood culture bottles compared with solid culture media and enrichment broth

The diagnosis of prosthetic joint infections and isolation of causative microorganisms has been found to be challenging in microbiology laboratories due to low sensitivity of microbiological culture. The aim of this study was to compare the use of conventional culture methods with the use of both enrichment broth and BacT/ALERT paediatric blood culture bottles, for the diagnosis of prosthetic joint infections. A total of 121 specimens from 44 patients were processed using three methods of microbiological culture: solid media, enrichment broth and paediatric bottles. The paediatric bottle method had a significantly lower (p<0.0001) time to detection than the standard solid media method, and was significantly more sensitive than solid media when used independently (93.33%, CI 83.27-98.09, vs 60.00%, CI 45.43-73.33). The combination use of solid media with paediatric bottles was found to be superior to the conventional solid media method and combination use with enrichment broth.