Blood Cultures Of Pediatric Patients Research Articles

Recovery of pathogens with implementation of a weight-based algorithm for pediatric blood cultures: an observational intervention study

BackgroundRecovering pathogenic bacteria and yeast from pediatric blood cultures and reliably distinguishing between pathogens and contaminants are likely to be improved by increasing the volume of blood submitted to microbiology laboratories for culturing beyond the low volumes that have historically have been used. The primary aim of this study was to assess whether the pathogen recovery rate would increase after implementation of a weight-based algorithm for determining the intended volume of blood submitted for culturing.Secondary aims were to: 1) evaluate the effects of the algorithm implementation on the blood culture contamination rate; 2) determine whether pathogens might be found more often than contaminants in several as opposed to single bottles when more than one bottle is submitted; and 3) describe the microbiological findings for pathogens and contaminants in blood cultures by applying a clinical validation of true blood culture positivity.MethodsA pre-post comparison of positivity and contamination rates after increasing the theoretical blood volume and number of blood culture bottles was performed, on the basis of a clinical validation of blood culture findings as pathogens vs contaminants.ResultsWe examined 5327 blood cultures, including 186 with growth (123 true positives and 63 contaminated). The rate of true positive blood cultures significantly increased from 1.6% (42/2553) pre to 2.9% (81/2774, p = .002) post intervention. The rate of contaminated blood cultures did not change significantly during the study period (1.4% [35/2553] pre vs 1.0% [28/2774], p = .222) post intervention), but the proportion of contaminated cultures among all positive cultures decreased from 45% (35/77) pre to 26% (28/109, p = .005) post intervention. A microorganism that grew in a single bottle was considered a contaminant in 35% (8/23) of cases, whereas a microorganism that grew in at least two bottles was considered a contaminant in 2% (1/49, p < .001) of cases. According to common classification criteria relying primarily on the identity of the microorganism, 14% (17/123) of the recovered pathogens would otherwise have been classified as contaminants.ConclusionImplementation of a weight-based algorithm to determine the volume and number of blood cultures in pediatric patients is associated with an increase in the pathogen recovery rate.

Molecular Epidemiology of Stenotrophomonas maltophilia Strains Isolated from Bacteremia in Hospitalized Children.

The aim of this study was to determine the phenotypic and genotypic characteristics of Stenotrophomonas maltophilia isolates obtained from blood culture samples of pediatric patients hospitalized in Borujerd and Hamadan hospitals in western Iran. Oxidase-negative isolates were collected from the blood cultures of pediatric patients. S. maltophilia isolates were identified and confirmed by routine microbiological and molecular testing. Antibiotic susceptibility of the isolates was determined. The phenotypic and genotypic biofilm-forming ability of the isolates were investigated. Molecular typing of all isolates was performed by repetitive element sequence-based polymerase chain reaction. Out of 450 oxidase-negative bacilli, 72 (16.0%) were identified as S. maltophilia isolates. Biofilm assay results showed strong biofilm formation in 19 (26.4%) isolates, moderate in 38 (52.8%), weak in 10 (13.9%), and no biofilm formation in five (6.9%) isolates. Biofilm-associated genes rmlA, rpfF, and spgM were detected respectively in 59 (81.9%), 54 (75.0%), and 72 (100%) of isolates. Antimicrobial susceptibility testing showed that 67 (93.1%) isolates were sensitive to trimethoprim-sulfamethoxazole. All isolates were sensitive to levofloxacin and resistant to ceftazidime. The S. maltophilia isolates were grouped into 14 different types of repetitive sequence by repetitive element sequence-based polymerase chain reaction analysis. The results of this study indicate that S. maltophilia should be considered an important opportunistic pathogen in pediatric units. Different genotypes of S. maltophilia with the ability to form a biofilm (an important virulence factor) were circulating in the hospitals investigated. Levofloxacin and trimethoprim-sulfamethoxazole are recommended to treat S. maltophilia infections.

Initial blood cultures in pediatric patients with central line infections and short bowel syndrome can direct a treatment plan that can reduce hospital length of stay

BackgroundChildren with short bowel syndrome requiring parenteral nutrition are at high risk of recurrent central line–associated bloodstream infections requiring inpatient admission. Predicting responses to treatment at admission could help revise our current treatment algorithm and reduce the length of stay. MethodsWe conducted a retrospective study of all intestinal rehabilitation clinic patients admitted for central line–associated bloodstream infections at our academic hospital between January 2018 and June 2021. Demographic, blood culture, and treatment response data were analyzed. ResultsThere were 180 separate admissions for central line–associated bloodstream infections, involving 24 patients who met the inclusion and exclusion criteria. The average length of stay was 9.4 days, and 77.1% of the admissions exceeded the predicted length of stay. All patients were treated according to the standard protocols. In the initial blood cultures, 64.4%, 10.6%, and 25% grew a single bacterium, a single fungus, and multiple organisms, respectively. After treatment initiation, 73.3% of single bacterial infections did not show additional positive cultures. However, 78.9% and 48.9% of fungal and multiple organism infections, respectively, had multiple positive cultures, even after initiating treatment. All positive repeat cultures were treated with an ethanol lock for 24 hours in addition to continued treatment. The treatment preserved 90.5% of the catheters. ConclusionPatients experiencing short bowel syndrome admitted for central line–associated bloodstream infections with initial cultures growing fungi or multiple organisms frequently had multiple positive cultures, whereas those with a single bacterial organism did not. Discharging patients who grew a single bacterial organism and placing an initial ethanol lock on those with multiple or fungal organisms could reduce the average length of stay, even if some of these patients would require readmission for line removal.

Targeted metabolomics analysis of serum and Mycobacterium tuberculosis antigen-stimulated blood cultures of pediatric patients with active and latent tuberculosis

Profound tuberculosis (TB)-induced metabolic changes reflected in the blood metabolomic profile may provide an opportunity to identify specific markers of Mycobacterium tuberculosis infection. Using targeted liquid chromatography tandem mass spectrometry, we compared the levels of 30 small metabolites, including amino acids and derivatives, and small organic compounds in serum and M.tb antigen-stimulated whole blood cultures of active TB children, latent TB (LTBI) children, nonmycobacterial pneumonia (NMP) children, and healthy controls (HCs) to assess their potential as biomarkers of childhood TB. We found elevated levels of leucine and kynurenine combined with reduced concentrations of citrulline and glutamine in serum and blood cultures of TB and LTBI groups. LTBI status was additionally associated with a decrease in valine levels in blood cultures. The NMP metabolite profile was characterized by an increase in citrulline and glutamine and a decrease in leucine, kynurenine and valine concentrations. The highest discriminatory potential for identifying M.tb infection was observed for leucine detected in serum and kynurenine in stimulated blood cultures. The use of targeted metabolomics may reveal metabolic changes in M.tb-infected children, and the obtained results are a proof of principle of the usefulness of metabolites in the auxiliary diagnosis of TB in children.

Update on Pediatric Sepsis in Mexico.

The main objective of this work was to determine and update the causal agents’ antibiotic sensitivity and resistance patterns on pediatric sepsis in a population of northeast Mexico. It is a cross-sectional study showing the results of blood cultures of pediatric patients with a presumptive diagnosis of sepsis were reviewed according to the SOFA criteria during 2020 in a public hospital in Mexico. A total of 207 blood cultures were performed and analyzed. The main isolated microorganisms were Staphylococcus, followed by Klebsiella and Escherichia. Several microorganisms showed 100% of sensitivity to different antibiotics or antifungals, some of them include Vancomycin, Voriconazole, Meropenem, Ciprofloxacin, and Cefotaxime. Bacteria of genre Staphylococcus showed its highest sensitivity rate to Tigecycline with 63.3%. Too Staphylococcus showed the highest resistance rate to Oxacillin with 50%. Although the patterns of sepsis-causing germs are similar to those previously reported, the development of new drugs with greater efficacy is the main contribution.

A case of bacteremia caused by Leptotrichia trevisanii in pediatric patient with febrile neutropenia and review of literature.

Leptotrichia species are fastidious anaerobic, fusiform, pencil-shaped Gram-negative bacilli that reside in microbiota of humans. Leptotrichia species have increasingly been recognized as an opportunistic pathogen in humans, mainly in the immunocompromised patient. Anaerobic organisms have rarely been isolated from blood cultures of pediatric patients. In our study, we isolated Leptotrichia trevisanii from central venous catheter culture of a five-year-old male patient. It was identified with both matrix-assisted laser desorption ionization time-of-flight mass spectrometry and confirmed via 16S rRNA gene sequencing. The early recognition of anaerobic bacteremia and administration of appropriate antimicrobial and play an important role preventing mortality and morbidity in children. In our study we report a rarely diagnosed case of L. trevisanii bacteremia in a pediatric patient.

Molecular Characterization of Staphylococcus aureus Obtained from Blood Cultures of Paediatric Patients Treated in a Tertiary Care Hospital in Mexico.

PurposeStaphylococcus aureus is one of the main causative agents of hospital-acquired (HA) infections. In Mexico, information about the characteristics of clinical S. aureus isolates is limited. Our aim was to characterize S. aureus strains obtained from blood cultures of paediatric patients treated in a tertiary care hospital.Materials and MethodsWe analysed 249 S. aureus isolates over the period from 2006 to 2019, and their resistance profiles were determined. The isolates were classified into methicillin-resistant S. aureus (MRSA) or methicillin-sensitive S. aureus (MSSA). Staphylococcal cassettes chromosome mec (SCCmec) were detected. Virulence genes (cna, clfA, clfB, eta, etb, fnbA, fnbB, hla, pvl, sec, and tsst) were amplified, and their clonal relationships were established by pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST) and clonal complex (CC) typing. We reviewed one hundred medical files to collect clinical information.ResultsThirty-eight percent of the isolates were MRSA and showed an expanded profile of resistance to other non-beta-lactam antibiotics, while MSSA strains presented a reduced resistance profile. SCCmec-II was the most frequent element (86.3%). Eight virulence factors were detected in MSSA and six in MRSA. The pvl gene was detected in four MRSA-SCCmec-IV isolates (P≤0.0001). MRSA isolates were distributed among 14 clones and were classified into 15 sequence types (ST); the most frequent was ST1011 (17%). The most common CC in MRSA was CC5 (69%, P≤0.0001), and in MSSA, it was CC30 (30%, P≤0.0001). Eighty-seven percent of MRSA isolates were HA-MRSA, and 13% were community-acquired MRSA (CA-MRSA). Of 21 HA-MRSA isolates, 17 had SCCmec-II, while two CA-MRSA isolates had SCCmec-IV. Of MSSA isolates, 77% were derived from HA infections and 23% from CA infections.ConclusionMSSA isolates had more virulence factors. MRSA isolates were resistant to more non-beta-lactam antibiotics, and those with SCCmec-IV expressed a greater variety of virulence factors. Most S. aureus isolates belonged to CC5.

663. Improved Detection of ESBL and AmpC Beta-Lactamase Producing Isolates of Enterobacteriaceae in Pediatric Patients with Bloodstream Infections Using Combined Genotypic and Phenotypic Antimicrobial Susceptibility Testing

BackgroundInfections secondary to pathogens resistant to third-generation cephalosporins (3GC), such as extended-spectrum (ESBL) and AmpC β-lactamase (AmpC) producing Enterobacteriaceae, are increasing. Currently, there are no recommendations regarding identification of AmpC in Citrobacter, Enterobacter, Morganella and Serratia spp. (CEMS organisms). This study’s aim was to increase the detection of AmpC and ESBL producing Enterobacteriaceae in blood cultures from pediatric population by combining genotypic with phenotypic antimicrobial susceptibility testing (AST).MethodsAll first time Enterobacteriaceae isolates recovered from blood cultures of pediatric patients at CCHMC between January 2017 and December 2018 were evaluated. The Check-MDR CT103XL assay was used to determine the presence of AmpC and ESBL. AST was performed using the Vitek 2 platform. Phenotypic ESBL resistance was defined by resistant to either ceftriaxone of ceftazidime using CLSI breakpoints. Combined cefoxitin resistance with ceftriaxone or ceftazidime resistance was used to define phenotypic AmpC (EUCAST standards).ResultsThere were 170 isolates, from 147 patients, with 21 (12.4%) AmpC and 18 (10.6%) ESBL genes detected. Using AST, 11 (6.5%) and 26 (15.3%) isolates met AmpC and ESBL phenotypic criteria respectively. However, 14 of the isolates with AmpC genes detected and 2 of isolates with ESBL genes detected failed to meet phenotypic criteria. In addition, 4 (19%) of 21 AmpC isolates were susceptible to cefoxitin and 3GC while both E. coli and S. marcescens genotypic ESBL isolates were susceptible to 3GC.Number of AmpC- and ESBL- Producing Isolates Detected Using Phenotypic Method a,b, Genotypic Method and Combined Testing ConclusionWe identified 16 (9.4%) isolates with resistance genes detected but that failed to meet phenotypic criteria.Without molecular testing, patients with these isolates may have been treated with 3GC which could have resulted in treatment failure.The addition of genotypic testing to AST improved the identification of AmpC and ESBL organisms and provided clinically relevant data to guide treatment of resistant organisms. Combined testing is also beneficial for infection control and epidemiological purposes.Disclosures All Authors: No reported disclosures

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

Genomic insights of international clones of Haemophilus influenzae causing invasive infections in vaccinated and unvaccinated infants

The emergence of invasive Haemophilus influenzae infections in vaccinated patient is a public health concern. We have investigated the genomic basis of invasiveness and possible vaccine failure in H. influenzae causing invasive disease in vaccinated and unvaccinated children in Brazil. Three H. influenzae strains isolated from blood cultures of pediatric patients were sequenced. Serotype, MLST, resistome and virulome were predicted using bioinformatic tools, whereas single nucleotide polymorphisms (SNPs) analysis of cap loci and the presence of the putative virulence-enhancing IS1016-bexA partial deletion were predicted in silico. Infections were caused by H. influenzae type a (Hia), type b (Hib) and nontypeable (NTHi), belonging to international high-risk clones of sequence types ST23, ST6 and ST368, respectively, which have been identified in North American, European and Asian countries. Convergence of ampicillin resistance and virulence in Hib-ST6 was supported by blaTEM-1B and deletion in the bexA gene, whereas presence of SNPs in the cap-b locus was associated with antigenic modifications of the capsule structure. Hia-ST23 and NTHi-ST368 strains carried galU, lpsA, opsX, rfaF, iga1, lgtC and lic1/lic2 virulence genes, associated with colonization, adaptation and damage to the lung, or invasiveness. In summary, deletion in the bexA gene and presence of SNPs in the cap locus of Hib could be contributing to invasive disease and possible vaccine failure in pediatric patients, whereas serotype replacement of Hib with type “a” and NTHi strains denotes the ability of non-vaccine serotypes to re-colonize vaccinated patients. Finally, the dissemination of international high-risk clones of H. influenzae emphasizes the importance of monitoring changes in the molecular epidemiology of invasive H. influenzae disease.

Rapid identification of microorganisms from positive blood cultures in pediatric patients by MALDI-TOF MS: Sepsityper kit versus short-term subculture

Background and aimThe rapid diagnosis of bloodstream infection (BSI) often leads to better clinical outcomes. The present study was conducted to compare two rapid protocols (Sepsityper kit and short-term subculture) for matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS)-based identification of microorganisms from positive blood cultures in pediatric patients. MethodsThis study was conducted between May 1, 2018, and April 30, 2019, at a tertiary children's hospital in eastern China. Only monomicrobial blood cultures included in this study were used to conduct the Sepsityper kit protocol and short-term subculture protocol at the same time. ResultsIn total, 115 monomicrobial blood cultures were included in this study. For the Sepsityper kit protocol, 85.2% and 64.3% of microorganisms were correctly identified to the genus (score ≥ 1.700) and species levels (score ≥ 2.000), respectively. For the short-term subculture protocol, 89.6% and 70.4% of microorganisms were correctly identified to the genus and species levels, respectively. At the genus level (P = .321) or the species level (P = .325), there was no significant difference between the Sepsityper kit protocol and the short-term subculture protocol. Moreover, the short-term subculture protocol exhibited similar performance between Gram-positive bacteria (GPB) and Gram-negative bacteria (GNB) (the genus level: 93.7% (GPB) versus 87.9% (GNB), P = .518; the species level: 68.4% (GPB) versus 81.8% (GNB), P = .147). In addition, the Sepsityper kit protocol exhibited similar performance between GPB and GNB at the genus level (86.1% (GPB) versus 84.8% (GNB), P = 1.000). However, the Sepsityper kit protocol exhibited better performance in GNB at the species level (58.2% (GPB) versus 81.8% (GNB), P = .017). The rates of yeast-like fungi were correctly identified to the genus level (0.0%) or the species level (0.0%) for short-term subculture protocol were significantly lower than those of other microorganisms (the genus level: 92.0%, P = .001; the species level: 72.3%, P = .024). However, a similar result of identification was not found using the Sepsityper kit protocol (the genus level: P = .384; the species level: P = .599). In addition, the two rapid protocols both exhibited better performance at the genus level when the time to positivity (TTP) of blood cultures <19 h (the Sepsityper kit protocol: 91.8% (TTP < 19 h) versus 77.8% (TTP ≥ 19 h), P = .034; the short-term subculture protocol: 95.1% (TTP < 19 h) versus 83.3% (TTP ≥ 19 h), P = .040). In addition, the two rapid protocols both exhibited better performance at the species level when the TTP of blood cultures was <19 h (the Sepsityper kit protocol: 78.7% (TTP < 19 h) versus 48.1% (TTP ≥ 19 h), P = .000; the short-term subculture protocol: 83.6% (TTP < 19 h) versus 55.6% (TTP ≥ 19 h), P = .001). ConclusionThe Sepsityper kit protocol and short-term subculture protocol are both reliable and rapid methods for the identification of most microorganisms from positive blood cultures in pediatric patients. The performance of these two rapid protocols is associated with the TTP of blood cultures.

Time to Positivity as a Prognostic Tool in the Performance of Short-Term Subculture for MALDI-TOF MS-Based Identification of Microorganisms from Positive Blood Cultures in Pediatric Patients.

The present study aimed to investigate the relationship between the time to positivity (TTP) of blood cultures and the performance of short-term subculture for MALDI-TOF MS-based identification of microorganisms from positive blood cultures in pediatric patients. The study was conducted between April 2018 and July 2019 at a tertiary children's hospital in Eastern China and the TTP of all the blood cultures included was retrospectively collected at the same time. In total, 332 monomicrobial blood cultures were included in the study. Blood cultures that were identified at the genus level (score ≥ 1.700) by the short-term subculture protocol had shorter TTP (median TTP: 17.5h) than of those not identified (median TTP: 24.6h; P < 10-3). Those that were identified at the species level (score ≥ 2.000) by the short-term subculture protocol also had shorter TTP (median TTP: 16.7h) than of those not identified (median TTP: 21.7h; P < 10-3). ROC curve analysis indicated that the TTP cutoff value to the genus level of the short-term subculture protocol was 18.2h (area under the curve (AUC): 0.801; 95% confidence interval (CI) 0.741-0.861; P < 10-3). At the same time, the TTP cutoff value to the species level of the short-term subculture protocol was 18.1h (AUC: 0.747; 95% CI 0.694-0.800; P < 10-3). TTP is a convenient and valuable prognostic tool for the determination of the performance of short-term subculture for MALDI-TOF MS-based identification of microorganisms from positive blood cultures in pediatric patients.

Things We Do For No Reason: Blood Cultures for Uncomplicated Skin and Soft Tissue Infections in Children.

Skin and soft tissue infections (SSTIs) are common pediatric diagnoses in both outpatient and inpatient settings. Blood cultures are frequently obtained for evaluation of SSTIs. Multiple studies have demonstrated that blood cultures rarely demonstrate true pathogenic bacterial growth, and even positive cultures do not change clinical management. Obtaining blood cultures has been associated with increased length of hospital stay. In addition, false-positive blood cultures may occur and result in repeat blood cultures and increased hospital charges. Clinicians should avoid obtaining blood cultures in pediatric patients with uncomplicated SSTIs but instead should focus on obtaining wound cultures when possible.

Blood Cultures in Hospitalized Pneumonia Patients

Research Article| December 01 2017 Blood Cultures in Hospitalized Pneumonia Patients AAP Grand Rounds (2017) 38 (6): 67. https://doi.org/10.1542/gr.38-6-67 Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Cite Icon Cite Search Site Citation Blood Cultures in Hospitalized Pneumonia Patients. AAP Grand Rounds December 2017; 38 (6): 67. https://doi.org/10.1542/gr.38-6-67 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search toolbar search search input Search input auto suggest filter your search All PublicationsAll JournalsAAP Grand RoundsPediatricsHospital PediatricsPediatrics In ReviewNeoReviewsAAP NewsAll AAP Sites Search Advanced Search Topics: blood culture, pneumonia Source: Neuman MI, Hall M, Lipsett SC, et al. Utility of blood culture among children hospitalized with community-acquired pneumonia. Pediatrics. 2017; 140(3). pii: e20171013; doi: https://doi.org/10.1542/peds.2017-1013Google Scholar Investigators at multiple institutions conducted a cross-sectional study to assess the prevalence and microbiology of bacteremia among children hospitalized with community-acquired pneumonia (CAP). Children aged 3 months to 18 years without complex chronic conditions who were hospitalized with CAP at 1 of 6 tertiary children’s hospitals belonging to the Pediatric Health Information System Plus database were eligible. CAP was identified by using ICD-9 codes contained in the database. Data on demographics and length of stay were also extracted. The primary outcome was having a blood culture performed during the hospitalization, as determined via database review. Blood culture results were classified as either positive or negative, with positive results further classified as being pathogenic or contaminant. Bacteremia was defined as a blood culture result positive for a pathogen. Among these, the pathogen was classified as either susceptible or nonsusceptible to penicillin on the basis of the minimum inhibitory concentration of <2 μg/mL. Investigators determined the prevalence of bacteremia, the frequencies of pathogens, and the susceptibility to penicillin, and compared the characteristics of children who underwent blood culture with those who did not. There were 7,509 participants included in the analysis. Overall, 2,568 children (34.2%) had a blood culture performed. Participants with a blood culture were more likely to have private insurance and have a longer length of stay. There were 65 blood cultures that grew a pathogen, resulting in a prevalence of bacteremia of 0.9% (95% CI, 0.7%–1.1%) among all participants and 2.5% (95% CI, 2.0%–3.2%) among participants with a blood culture. The most common pathogen was Streptococcus pneumoniae (78.5%), and 92% of S pneumoniae isolates were susceptible to penicillin. Among all pathogens isolated, 82% were susceptible to penicillin. Only 0.43% (95% CI, 0.23%–0.77%) of children with a blood culture performed grew an organism resistant to penicillin. The investigators conclude that the prevalence of bacteremia is low among children without comorbidities who are hospitalized for CAP. Dr Winer has disclosed no financial relationship relevant to this commentary. This commentary does not contain a discussion of an unapproved/investigative use of a commercial product/device. Whether or not to perform blood cultures in pediatric patients who are admitted to the hospital with nonsevere, noncomplicated CAP has been an ongoing debate. The Pediatric Infectious Diseases Society and the Infectious Diseases Society of America clinical practice guideline for CAP in infants and children >3 months of age recommend blood cultures in children requiring hospitalization for presumed bacterial CAP that is moderate to severe, particularly those with complicated pneumonia.1 This is a strong recommendation, despite low-quality evidence. In the evidence summary, the authors of the guideline state that the rate of bacteremia is likely to be low in patients without effusion, sepsis, or organ dysfunction. They cite 1 study in which 5 of the 6 patients with positive... You do not currently have access to this content.

Identification of Candida parapsilosis Sensu Lato in Pediatric Patients and Antifungal Susceptibility Testing.

A total of 59 Candida parapsilosis sensu stricto and 1 Candida orthopsilosis recovered from catheters and blood cultures of pediatric patients from the northeastern region of Argentina were studied. Susceptibility to azoles, amphotericin B, and echinocandins was tested by the broth microdilution method. According to CLSI clinical breakpoints, >91% of the strains were azole susceptible, whereas 15% showed high amphotericin B MICs.

Assessment of anaerobic blood cultures in pediatric oncology patients

IntroductionThe routine use of a single aerobic bottle for blood culture in pediatric patients has become commonplace, as anaerobic bacteria are not frequently involved in clinically significant infections. The aim of this study was to assess the usefulness of routinely performing anaerobic blood cultures in pediatric oncology patients. MethodsProspective study was conducted on pediatric (<18 years) patients affected with febrile syndrome after receiving chemotherapy for hematological or solid malignancies. Samples were inoculated into pediatric aerobic and standard anaerobic bottles (BacT/Alert automatic system). Strains were considered clinically significant, or deemed as contaminants, depending on isolation circumstances and clinical criteria. ResultsA total of 876 blood cultures from 228 patients were processed during the 21-month study period (January 2014 to September 2015). Baseline diagnosis included 143 solid tumors and 67/18 cases of leukemia/lymphoma. Bacterial growth was detected in 90 (10.2%) blood cultures for 95 different isolates, of which 62 (7.1%)/63 isolates were considered clinically significant. Among the latter, 38 (60.3%) microorganisms grew in both aerobic and anaerobic bottles, 18 (28.6%) only in aerobic bottles, and 7 (11.1%) only in anaerobic bottles. Gram-negative bacilli (33; 52.4%), mainly from the Enterobacteriaceae family, were the most frequently isolated microorganisms. Overall, only 3 out of 90 isolates (3.3%) were strict anaerobes (Propionibacterium acnes), and all of them were deemed contaminants. ConclusionStrict anaerobes did not cause significant infections in febrile pediatric oncology patients, and anaerobic blood culture bottles offered no additional advantages over aerobic media. Our results suggest that routine blood cultures should be solely processed in aerobic media in this group of patients.

Assessment of anaerobic blood cultures in pediatric oncology patients

IntroductionThe routine use of a single aerobic bottle for blood culture in pediatric patients has become commonplace, as anaerobic bacteria are not frequently involved in clinically significant infections. The aim of this study was to assess the usefulness of routinely performing anaerobic blood cultures in pediatric oncology patients. MethodsProspective study was conducted on pediatric (<18 years) patients affected with febrile syndrome after receiving chemotherapy for hematological or solid malignancies. Samples were inoculated into pediatric aerobic and standard anaerobic bottles (BacT/Alert automatic system). Strains were considered clinically significant, or deemed as contaminants, depending on isolation circumstances and clinical criteria. ResultsA total of 876 blood cultures from 228 patients were processed during the 21-month study period (January 2014 to September 2015). Baseline diagnosis included 143 solid tumors and 67/18 cases of leukemia/lymphoma. Bacterial growth was detected in 90 (10.2%) blood cultures for 95 different isolates, of which 62 (7.1%)/63 isolates were considered clinically significant. Among the latter, 38 (60.3%) microorganisms grew in both aerobic and anaerobic bottles, 18 (28.6%) only in aerobic bottles, and 7 (11.1%) only in anaerobic bottles. Gram-negative bacilli (33; 52.4%), mainly from the Enterobacteriaceae family, were the most frequently isolated microorganisms. Overall, only 3 out of 90 isolates (3.3%) were strict anaerobes (Propionibacterium acnes), and all of them were deemed contaminants. ConclusionStrict anaerobes did not cause significant infections in febrile pediatric oncology patients, and anaerobic blood culture bottles offered no additional advantages over aerobic media. Our results suggest that routine blood cultures should be solely processed in aerobic media in this group of patients.

Antibiotic Resistance of Gram-Negative Bacilli Isolated from Pediatric Patients with Nosocomial Bloodstream Infections in a Mexican Tertiary Care Hospital

Background: Gram-negative bacilli are the most common bacteria causing nosocomial bloodstream infections (NBSIs) in Latin American countries. Methods: The antibiotic resistance profiles of Gram-negative bacilli isolated from blood cultures in pediatric patients with NBSIs over a 3-year period in a tertiary care pediatric hospital in Mexico City were determined using the VITEK-2 system. Sixteen antibiotics were tested to ascertain the resistance rate and the minimum inhibitory concentration using the Clinical Laboratory Standards Institute (CLSI) broth micro-dilution method as a reference. Results: A total of 931 isolates were recovered from 847 clinically significant episodes of NBSI. Of these, 477 (51.2%) were caused by Gram-negative bacilli. The most common Gram-negative bacilli found were Klebsiella pneumoniae (30.4%), Escherichia coli (18.9%), Enterobacter cloacae (15.1%), Pseudomonas aeruginosa (9.9%), and Acinetobacter baumannii (4.6%). More than 45 and 60% of the K. pneumoniae and E. coli isolates, respectively, were resistant to cephalosporins, and 64% of the E. coli isolates were resistant to fluoroquinolones. A. baumannii exhibited low rates of resistance to antibiotics tested. In the E. cloacae and P. aeruginosa isolates, no rates of resistance higher than 38% were observed. Conclusions: In this study, we found that the proportion of NBSIs due to antibiotic-resistant organisms is increasing in a tertiary care pediatric hospital of Mexico.

Activity of linezolid and daptomycin against methicillin-resistant coagulase-negative staphylococci with increased MIC for vancomycin isolated from blood cultures in pediatric patients

We evaluated minimal inhibitory concentration (MIC) for vancomycin, daptomycin, and linezolid in methicillin-resistant coagulase-negative staphylococci (MR-CoNS). Minimal inhibitory concentration of 2–4 mg/l for vancomycin was observed in 16% of strains, and among them 19% had MIC at breakpoint for daptomycin or linezolid. Among strains completely susceptible to vancomycin, 16% had MIC at breakpoint for daptomycin and 11% had for linezolid. This large proportion of pathogens with MIC around the breakpoint suggests a possible risk of treatment failure with these drugs. This phenomenon is worth further and constant monitoring.

The Prevalence of Bacteremia in Pediatric Patients With Community-Acquired Pneumonia: Guidelines to Reduce the Frequency of Obtaining Blood Cultures

The goal of this study was to determine the prevalence of bacteremia in pediatric patients with community-acquired pneumonia (CAP) at our institution and to test the effectiveness of newly developed guidelines for obtaining blood cultures. Using recent literature and local expert opinion, institutional guidelines for obtaining blood cultures in pediatric patients with CAP were developed. A retrospective chart review of children treated in the emergency department or admitted for CAP from January 2010 through June 2011 was conducted. Demographic and clinical data were collected, including results of blood cultures. Chi2 tests assessed for variables associated with bacteremia, whether a blood culture was obtained, and if the decision to obtain a culture was appropriate based on our guidelines. The study included 330 patients; 155 (47%) blood cultures were obtained in our patient population. Five cultures were true-positive findings, making the prevalence of bacteremia 3.2% in patients with blood cultures and 1.5% in all patients. All 5 true positive results met criteria for blood culture based on our guidelines. Applying our guidelines retrospectively, the decision to obtain a blood culture met criteria in 55% of the cases. Bivariate analysis showed that patients discharged from the emergency department had higher rates of guideline-appropriate decisions than patients admitted. Radiographic findings were associated with making a guideline-appropriate decision regarding blood culture. Instituting local guidelines that limit the frequency of obtaining blood cultures in pediatric patients with CAP is likely to capture any patient with bacteremia. This study suggests that blood cultures may not need to be routinely obtained in all patients admitted to the hospital with CAP.