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Correction: Achievement of therapeutic antibiotic exposures using Bayesian dosing software in critically unwell children and adults with sepsis. Intensive Care Med 2024; 50:810. [PMID: 38563901 PMCID: PMC11078779 DOI: 10.1007/s00134-024-07393-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
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High-risk Escherichia coli clones that cause neonatal meningitis and association with recrudescent infection. eLife 2024; 12:RP91853. [PMID: 38622998 PMCID: PMC11021048 DOI: 10.7554/elife.91853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/17/2024] Open
Abstract
Neonatal meningitis is a devastating disease associated with high mortality and neurological sequelae. Escherichia coli is the second most common cause of neonatal meningitis in full-term infants (herein NMEC) and the most common cause of meningitis in preterm neonates. Here, we investigated the genomic relatedness of a collection of 58 NMEC isolates spanning 1974-2020 and isolated from seven different geographic regions. We show NMEC are comprised of diverse sequence types (STs), with ST95 (34.5%) and ST1193 (15.5%) the most common. No single virulence gene profile was conserved in all isolates; however, genes encoding fimbrial adhesins, iron acquisition systems, the K1 capsule, and O antigen types O18, O75, and O2 were most prevalent. Antibiotic resistance genes occurred infrequently in our collection. We also monitored the infection dynamics in three patients that suffered recrudescent invasive infection caused by the original infecting isolate despite appropriate antibiotic treatment based on antibiogram profile and resistance genotype. These patients exhibited severe gut dysbiosis. In one patient, the causative NMEC isolate was also detected in the fecal flora at the time of the second infection episode and after treatment. Thus, although antibiotics are the standard of care for NMEC treatment, our data suggest that failure to eliminate the causative NMEC that resides intestinally can lead to the existence of a refractory reservoir that may seed recrudescent infection.
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Achievement of therapeutic antibiotic exposures using Bayesian dosing software in critically unwell children and adults with sepsis. Intensive Care Med 2024; 50:539-547. [PMID: 38478027 PMCID: PMC11018654 DOI: 10.1007/s00134-024-07353-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2023] [Accepted: 02/11/2024] [Indexed: 03/26/2024]
Abstract
PURPOSE Early recognition and effective treatment of sepsis improves outcomes in critically ill patients. However, antibiotic exposures are frequently suboptimal in the intensive care unit (ICU) setting. We describe the feasibility of the Bayesian dosing software Individually Designed Optimum Dosing Strategies (ID-ODS™), to reduce time to effective antibiotic exposure in children and adults with sepsis in ICU. METHODS A multi-centre prospective, non-randomised interventional trial in three adult ICUs and one paediatric ICU. In a pre-intervention Phase 1, we measured the time to target antibiotic exposure in participants. In Phase 2, antibiotic dosing recommendations were made using ID-ODS™, and time to target antibiotic concentrations were compared to patients in Phase 1 (a pre-post-design). RESULTS 175 antibiotic courses (Phase 1 = 123, Phase 2 = 52) were analysed from 156 participants. Across all patients, there was no difference in the time to achieve target exposures (8.7 h vs 14.3 h in Phase 1 and Phase 2, respectively, p = 0.45). Sixty-one courses in 54 participants failed to achieve target exposures within 24 h of antibiotic commencement (n = 36 in Phase 1, n = 18 in Phase 2). In these participants, ID-ODS™ was associated with a reduction in time to target antibiotic exposure (96 vs 36.4 h in Phase 1 and Phase 2, respectively, p < 0.01). These patients were less likely to exhibit subtherapeutic antibiotic exposures at 96 h (hazard ratio (HR) 0.02, 95% confidence interval (CI) 0.01-0.05, p < 0.01). There was no difference observed in in-hospital mortality. CONCLUSIONS Dosing software may reduce the time to achieve target antibiotic exposures. It should be evaluated further in trials to establish its impact on clinical outcomes.
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A convergent evolutionary pathway attenuating cellulose production drives enhanced virulence of some bacteria. Nat Commun 2024; 15:1441. [PMID: 38383596 PMCID: PMC10881479 DOI: 10.1038/s41467-024-45176-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2023] [Accepted: 01/16/2024] [Indexed: 02/23/2024] Open
Abstract
Bacteria adapt to selective pressure in their immediate environment in multiple ways. One mechanism involves the acquisition of independent mutations that disable or modify a key pathway, providing a signature of adaptation via convergent evolution. Extra-intestinal pathogenic Escherichia coli (ExPEC) belonging to sequence type 95 (ST95) represent a global clone frequently associated with severe human infections including acute pyelonephritis, sepsis, and neonatal meningitis. Here, we analysed a publicly available dataset of 613 ST95 genomes and identified a series of loss-of-function mutations that disrupt cellulose production or its modification in 55.3% of strains. We show the inability to produce cellulose significantly enhances ST95 invasive infection in a rat model of neonatal meningitis, leading to the disruption of intestinal barrier integrity in newborn pups and enhanced dissemination to the liver, spleen and brain. Consistent with these observations, disruption of cellulose production in ST95 augmented innate immune signalling and tissue neutrophil infiltration in a mouse model of urinary tract infection. Mutations that disrupt cellulose production were also identified in other virulent ExPEC STs, Shigella and Salmonella, suggesting a correlative association with many Enterobacteriaceae that cause severe human infection. Together, our findings provide an explanation for the emergence of hypervirulent Enterobacteriaceae clones.
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Rapid nanopore sequencing and predictive susceptibility testing of positive blood cultures from intensive care patients with sepsis. Microbiol Spectr 2024; 12:e0306523. [PMID: 38193658 PMCID: PMC10846127 DOI: 10.1128/spectrum.03065-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Accepted: 12/15/2023] [Indexed: 01/10/2024] Open
Abstract
We aimed to evaluate the performance of Oxford Nanopore Technologies (ONT) sequencing from positive blood culture (BC) broths for bacterial identification and antimicrobial susceptibility prediction. Patients with suspected sepsis in four intensive care units were prospectively enrolled. Human-depleted DNA was extracted from positive BC broths and sequenced using ONT (MinION). Species abundance was estimated using Kraken2, and a cloud-based system (AREScloud) provided in silico predictive antimicrobial susceptibility testing (AST) from assembled contigs. Results were compared to conventional identification and phenotypic AST. Species-level agreement between conventional methods and AST predicted from sequencing was 94.2% (49/52), increasing to 100% in monomicrobial infections. In 262 high-quality AREScloud AST predictions across 24 samples, categorical agreement (CA) was 89.3%, with major error (ME) and very major error (VME) rates of 10.5% and 12.1%, respectively. Over 90% CA was achieved for some taxa (e.g., Staphylococcus aureus) but was suboptimal for Pseudomonas aeruginosa. In 470 AST predictions across 42 samples, with both high quality and exploratory-only predictions, overall CA, ME, and VME rates were 87.7%, 8.3%, and 28.4%. VME rates were inflated by false susceptibility calls in a small number of species/antibiotic combinations with few representative resistant isolates. Time to reporting from sequencing could be achieved within 8-16 h from BC positivity. Direct sequencing from positive BC broths is feasible and can provide accurate predictive AST for some species. ONT-based approaches may be faster but significant improvements in accuracy are required before it can be considered for clinical use.IMPORTANCESepsis and bloodstream infections carry a high risk of morbidity and mortality. Rapid identification and susceptibility prediction of causative pathogens, using Nanopore sequencing direct from blood cultures, may offer clinical benefit. We assessed this approach in comparison to conventional phenotypic methods and determined the accuracy of species identification and susceptibility prediction from genomic data. While this workflow holds promise, and performed well for some common bacterial species, improvements in sequencing accuracy and more robust predictive algorithms across a diverse range of organisms are required before this can be considered for clinical use. However, results could be achieved in timeframes that are faster than conventional phenotypic methods.
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Application of the ViroKey® SQ FLEX assay for detection of cytomegalovirus antiviral resistance. J Clin Virol 2023; 167:105556. [PMID: 37566984 DOI: 10.1016/j.jcv.2023.105556] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 07/13/2023] [Accepted: 08/03/2023] [Indexed: 08/13/2023]
Abstract
BACKGROUND Cytomegalovirus (CMV) is a viral infection which establishes lifelong latency, often reactivating and causing disease in immunosuppressed individuals, including haematopoietic stem cell transplant (HSCT) recipients. Treatment can be problematic due to antiviral resistance which substantially increases the risk of patient mortality. Diagnostic testing capabilities for CMV antiviral resistance in Australia and elsewhere have traditionally relied on gene-specific Sanger sequencing approaches, however, are now being superseded by next generation sequencing protocols. OBJECTIVE Provide a snapshot of local mutations and explore the feasibility of the ViroKeyࣨ® SQ FLEX Genotyping Assay (Vela Diagnostics Pty Ltd) by examining sequencing success. METHOD Performed sequencing on adult (n = 38) and paediatric (n = 81) plasma samples, over a large range of viral loads (above and below the assay recommended threshold of ≥1,000 International Units (IU)/mL; noting most of our paediatric samples have loads <1,000 IU/mL). RESULTS Eleven test runs (including three repeat runs; 14 to 15 samples per run) were conducted, and four runs were deemed valid. The overall individual sample success rate for the four evaluable test runs was 71.2% (42/59 samples); 80.4% (37/46) samples ≥1,000 IU/mL were valid. Ten clinically important antiviral resistance mutations were detected, the most common being A594V in the UL97 gene, found in 6 (5%) samples. CONCLUSIONS A range of technical issues were experienced, however with improvement this platform could be a useful addition to routine pathology workflows, providing timely antiviral resistance results for patients undergoing HSCT.
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Cytomegalovirus in children undergoing haematopoietic stem cell transplantation: a diagnostic and therapeutic approach to antiviral resistance. Front Pediatr 2023; 11:1180392. [PMID: 37325366 PMCID: PMC10267881 DOI: 10.3389/fped.2023.1180392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Accepted: 05/15/2023] [Indexed: 06/17/2023] Open
Abstract
Cytomegalovirus (CMV) is a ubiquitous virus which causes a mild illness in healthy individuals. In immunocompromised individuals, such as children receiving haematopoietic stem cell transplantation, CMV can reactivate, causing serious disease and increasing the risk of death. CMV can be effectively treated with antiviral drugs, but antiviral resistance is an increasingly common complication. Available therapies are associated with adverse effects such as bone marrow suppression and renal impairment, making the choice of appropriate treatment challenging. New agents are emerging and require evaluation in children to establish their role. This review will discuss established and emerging diagnostic tools and treatment options for CMV, including antiviral resistant CMV, in children undergoing haematopoietic stem cell transplant.
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Rapid molecular detection of CMY-2, and CTX-M group 1 and 9 variants via recombinase polymerase amplification. JAC Antimicrob Resist 2023; 5:dlad023. [PMID: 36936189 PMCID: PMC10020033 DOI: 10.1093/jacamr/dlad023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Accepted: 02/19/2023] [Indexed: 03/18/2023] Open
Abstract
Background Due to their prevalence worldwide, the β-lactamases CTX-M and plasmid-mediated CMY-2 are important antimicrobial resistance enzymes in a clinical setting. While culture- and PCR-based detection methods exist for these targets, they are time consuming and require specialist equipment and trained personnel to carry out. Methods In this study, three rapid diagnostic single-plex and a prototype triplex assay were developed, using recombinase polymerase amplification with lateral flow detection (RPA-LF), and tested for their sensitivity and specificity using two isolate DNA panels (n = 90 and n = 120 isolates). In addition, the RPA-LF assays were also tested with a small number of faecal extract samples (n = 18). Results The RPA-LF assays were able to detect bla CXT-M-group-1, bla CTX-M-group-9 and bla CMY-2-type variants with high sensitivity (82.1%-100%) and specificity (100%) within a short turnaround time (15-20 min for amplification and detection). Conclusions RPA-LF assays developed in this study have the potential to be used at or close to the point of care, as well as in low-resource settings, producing rapid results to support healthcare professionals in their treatment decisions.
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Detection of Streptococcus pyogenes M1 UK in Australia and characterization of the mutation driving enhanced expression of superantigen SpeA. Nat Commun 2023; 14:1051. [PMID: 36828918 PMCID: PMC9951164 DOI: 10.1038/s41467-023-36717-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 02/13/2023] [Indexed: 02/26/2023] Open
Abstract
A new variant of Streptococcus pyogenes serotype M1 (designated 'M1UK') has been reported in the United Kingdom, linked with seasonal scarlet fever surges, marked increase in invasive infections, and exhibiting enhanced expression of the superantigen SpeA. The progenitor S. pyogenes 'M1global' and M1UK clones can be differentiated by 27 SNPs and 4 indels, yet the mechanism for speA upregulation is unknown. Here we investigate the previously unappreciated expansion of M1UK in Australia, now isolated from the majority of serious infections caused by serotype M1 S. pyogenes. M1UK sub-lineages circulating in Australia also contain a novel toxin repertoire associated with epidemic scarlet fever causing S. pyogenes in Asia. A single SNP in the 5' transcriptional leader sequence of the transfer-messenger RNA gene ssrA drives enhanced SpeA superantigen expression as a result of ssrA terminator read-through in the M1UK lineage. This represents a previously unappreciated mechanism of toxin expression and urges enhanced international surveillance.
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Proof-of-concept, rapid, instrument-free molecular detection of Neisseria gonorrhoeae and ciprofloxacin susceptibility. J Antimicrob Chemother 2022; 77:2933-2936. [PMID: 35880750 DOI: 10.1093/jac/dkac242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Accepted: 06/07/2022] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVES To develop instrument-free point-of-care methods using recombinase polymerase amplification (RPA) technology coupled with a simple lateral flow detection system to detect Neisseria gonorrhoeae and susceptibility to ciprofloxacin. METHODS For identification of gonococcal infection, an RPA-based method was developed targeting the gonococcal porA pseudogene (NG-porA-RPA). For ciprofloxacin susceptibility, predictive WT sequences at codons 91 and 95 of the gonococcal gyrA DNase gene were targeted. Given the known complexities of SNP detection using RPA (e.g. the ability to accommodate mismatches) we trialled several different assays incorporating various additional non-template mismatches in the oligonucleotide sequences to reduce affinity for the mutant (resistant) gyrA sequences. Assays were evaluated using a bank of N. gonorrhoeae (n = 10) and non-gonococcal (n = 5) isolates and a panel of N. gonorrhoeae nucleic acid amplification test (NAAT)-positive clinical sample extracts (n = 40). RESULTS The NG-porA-RPA assay was specific to N. gonorrhoeae and provided a positive percentage agreement (PPA) of 87.5% (35/40) compared with a commercial N. gonorrhoeae NAAT when applied to the 40 clinical sample extracts. For gyrA, the non-template bases successfully reduced banding intensity for double-mutant strains (mutations at both 91 and 95), but not for rarer single-mutant (91 only) strains. The most promising gyrA assay, NG-gyrA-RPA08, correctly detected 83% (25/30) of infections from NAAT-positive clinical samples confirmed to have WT gyrA sequences based on Sanger sequencing. CONCLUSIONS These proof-of-concept data show that RPA technology has considerable promise for detecting N. gonorrhoeae and associated antibiotic susceptibility and would offer a diagnostic-based stewardship strategy identified as urgently needed by the WHO.
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Innovation in microsampling for therapeutic drug monitoring of gentamicin in neonates: a proof-of-concept study. Int J Antimicrob Agents 2022; 59:106513. [PMID: 34999238 DOI: 10.1016/j.ijantimicag.2021.106513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 12/15/2021] [Accepted: 12/22/2021] [Indexed: 11/24/2022]
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An innovative Antimicrobial Stewardship Program for children in remote and regional areas in Queensland, Australia: optimizing antibiotic use through timely intravenous-to-oral conversion. J Glob Antimicrob Resist 2021; 28:53-58. [PMID: 34915202 DOI: 10.1016/j.jgar.2021.11.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 11/03/2021] [Accepted: 11/12/2021] [Indexed: 10/19/2022] Open
Abstract
BACKGROUND Little is known about the benefits of timely conversion from intravenous (IV) to oral antibiotic therapy in children. We evaluated appropriateness of IV to oral conversion of antibiotic therapy in remote and regional areas following the implementation of a multifaceted package of interventions. METHODS The intervention package: clinician guidelines, medication review stickers, patient information leaflets, and educational resources was implemented in seven facilities in Queensland, Australia. Children with community acquired pneumonia and skin and soft tissue infections were switched to oral therapy if they met the required 'IV-to-oral switch' criteria. Data was collected for a 7-month period from May to November for the baseline (2018) and the intervention (2019) phases. RESULTS There were 357 patients enrolled in the study with 178 in the baseline and 179 in the intervention phase. The percentage of patients who were eligible to switch to oral therapy, within 24 hours of eligibility, increased from (156/178) 87.6% in the baseline phase to (174/179) 97.2% in the intervention phase (p = 0.003). The average number of extra IV days decreased from 0.45 days in the baseline period to 0.18 days in the intervention period (p < 0.001). The median patient length of stay was 2 days for both phases. The only adverse events recorded were line-associated infiltrates, with a decrease from 34.3% (61/178) (baseline) to 17.9% (32/179) (intervention) (p < 0.001). CONCLUSION A multifaceted intervention package to enhance timely IV to oral conversion of antibiotic therapy for children in remote and regional facilities is effective.
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Gram-negative neonatal sepsis in low- and lower-middle-income countries and WHO empirical antibiotic recommendations: A systematic review and meta-analysis. PLoS Med 2021; 18:e1003787. [PMID: 34582466 PMCID: PMC8478175 DOI: 10.1371/journal.pmed.1003787] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Accepted: 09/01/2021] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Neonatal sepsis is a significant global health issue associated with marked regional disparities in mortality. Antimicrobial resistance (AMR) is a growing concern in Gram-negative organisms, which increasingly predominate in neonatal sepsis, and existing WHO empirical antibiotic recommendations may no longer be appropriate. Previous systematic reviews have been limited to specific low- and middle-income countries. We therefore completed a systematic review and meta-analysis of available data from all low- and lower-middle-income countries (LLMICs) since 2010, with a focus on regional differences in Gram-negative infections and AMR. METHODS AND FINDINGS All studies published from 1 January 2010 to 21 April 2021 about microbiologically confirmed bloodstream infections or meningitis in neonates and AMR in LLMICs were assessed for eligibility. Small case series, studies with a small number of Gram-negative isolates (<10), and studies with a majority of isolates prior to 2010 were excluded. Main outcomes were pooled proportions of Escherichia coli, Klebsiella, Enterobacter, Pseudomonas, Acinetobacter and AMR. We included 88 studies (4 cohort studies, 3 randomised controlled studies, and 81 cross-sectional studies) comprising 10,458 Gram-negative isolates from 19 LLMICs. No studies were identified outside of Africa and Asia. The estimated pooled proportion of neonatal sepsis caused by Gram-negative organisms was 60% (95% CI 55% to 65%). Klebsiella spp. was the most common, with a pooled proportion of 38% of Gram-negative sepsis (95% CI 33% to 43%). Regional differences were observed, with higher proportions of Acinetobacter spp. in Asia and Klebsiella spp. in Africa. Resistance to aminoglycosides and third-generation cephalosporins ranged from 42% to 69% and from 59% to 84%, respectively. Study limitations include significant heterogeneity among included studies, exclusion of upper-middle-income countries, and potential sampling bias, with the majority of studies from tertiary hospital settings, which may overestimate the burden caused by Gram-negative bacteria. CONCLUSIONS Gram-negative bacteria are an important cause of neonatal sepsis in LLMICs and are associated with significant rates of resistance to WHO-recommended first- and second-line empirical antibiotics. AMR surveillance should underpin region-specific empirical treatment recommendations. Meanwhile, a significant global commitment to accessible and effective antimicrobials for neonates is required.
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MicroPIPE: validating an end-to-end workflow for high-quality complete bacterial genome construction. BMC Genomics 2021; 22:474. [PMID: 34172000 PMCID: PMC8235852 DOI: 10.1186/s12864-021-07767-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 06/03/2021] [Indexed: 11/23/2022] Open
Abstract
Background Oxford Nanopore Technology (ONT) long-read sequencing has become a popular platform for microbial researchers due to the accessibility and affordability of its devices. However, easy and automated construction of high-quality bacterial genomes using nanopore reads remains challenging. Here we aimed to create a reproducible end-to-end bacterial genome assembly pipeline using ONT in combination with Illumina sequencing. Results We evaluated the performance of several popular tools used during genome reconstruction, including base-calling, filtering, assembly, and polishing. We also assessed overall genome accuracy using ONT both natively and with Illumina. All steps were validated using the high-quality complete reference genome for the Escherichia coli sequence type (ST)131 strain EC958. Software chosen at each stage were incorporated into our final pipeline, MicroPIPE. Further validation of MicroPIPE was carried out using 11 additional ST131 E. coli isolates, which demonstrated that complete circularised chromosomes and plasmids could be achieved without manual intervention. Twelve publicly available Gram-negative and Gram-positive bacterial genomes (with available raw ONT data and matched complete genomes) were also assembled using MicroPIPE. We found that revised basecalling and updated assembly of the majority of these genomes resulted in improved accuracy compared to the current publicly available complete genomes. Conclusions MicroPIPE is built in modules using Singularity container images and the bioinformatics workflow manager Nextflow, allowing changes and adjustments to be made in response to future tool development. Overall, MicroPIPE provides an easy-access, end-to-end solution for attaining high-quality bacterial genomes. MicroPIPE is available at https://github.com/BeatsonLab-MicrobialGenomics/micropipe. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-021-07767-z.
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Optimising Treatment Outcomes for Children and Adults Through Rapid Genome Sequencing of Sepsis Pathogens. A Study Protocol for a Prospective, Multi-Centre Trial (DIRECT). Front Cell Infect Microbiol 2021; 11:667680. [PMID: 34249774 PMCID: PMC8261237 DOI: 10.3389/fcimb.2021.667680] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Accepted: 05/20/2021] [Indexed: 11/23/2022] Open
Abstract
Background Sepsis contributes significantly to morbidity and mortality globally. In Australia, 20,000 develop sepsis every year, resulting in 5,000 deaths, and more than AUD$846 million in expenditure. Prompt, appropriate antibiotic therapy is effective in improving outcomes in sepsis. Conventional culture-based methods to identify appropriate therapy have limited yield and take days to complete. Recently, nanopore technology has enabled rapid sequencing with real-time analysis of pathogen DNA. We set out to demonstrate the feasibility and diagnostic accuracy of pathogen sequencing direct from clinical samples, and estimate the impact of this approach on time to effective therapy when integrated with personalised software-guided antimicrobial dosing in children and adults on ICU with sepsis. Methods The DIRECT study is a pilot prospective, non-randomized multicentre trial of an integrated diagnostic and therapeutic algorithm combining rapid direct pathogen sequencing and software-guided, personalised antibiotic dosing in children and adults with sepsis on ICU. Participants and interventions DIRECT will collect microbiological and pharmacokinetic samples from approximately 200 children and adults with sepsis admitted to one of four ICUs in Brisbane. In Phase 1, we will evaluate Oxford Nanopore Technologies MinION sequencing direct from blood in 50 blood culture-proven sepsis patients recruited from consecutive patients with suspected sepsis. In Phase 2, a further 50 consecutive patients with suspected sepsis will be recruited in whom MinION sequencing will be combined with Bayesian software-guided (ID-ODS) personalised antimicrobial dosing. Outcome measures The primary outcome is time to effective antimicrobial therapy, defined as trough drug concentrations above the MIC of the pathogen. Secondary outcomes are diagnostic accuracy of MinION sequencing from whole blood, time to pathogen identification and susceptibility testing using sequencing direct from whole blood and from positive blood culture broth. Discussion Rapid pathogen sequencing coupled with antimicrobial dosing software has great potential to overcome the limitations of conventional diagnostics which often result in prolonged inappropriate antimicrobial therapy. Reduced time to optimal antimicrobial therapy may reduce sepsis mortality and ICU length of stay. This pilot study will yield key feasibility data to inform further, urgently needed sepsis studies. Phase 2 of the trial protocol is registered with the ANZCTR (ACTRN12620001122943). Trial registration Registered with the Australia New Zealand Clinical Trials Registry Number ACTRN12620001122943
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The use of continuous electronic prescribing data to infer trends in antimicrobial consumption and estimate the impact of stewardship interventions in hospitalized children. J Antimicrob Chemother 2021; 76:2464-2471. [PMID: 34109397 PMCID: PMC8361331 DOI: 10.1093/jac/dkab187] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Accepted: 05/10/2021] [Indexed: 11/15/2022] Open
Abstract
Background Understanding antimicrobial consumption is essential to mitigate the development of antimicrobial resistance, yet robust data in children are sparse and methodologically limited. Electronic prescribing systems provide an important opportunity to analyse and report antimicrobial consumption in detail. Objectives We investigated the value of electronic prescribing data from a tertiary children’s hospital to report temporal trends in antimicrobial consumption in hospitalized children and compare commonly used metrics of antimicrobial consumption. Methods Daily measures of antimicrobial consumption [days of therapy (DOT) and DDDs] were derived from the electronic prescribing system between 2010 and 2018. Autoregressive moving-average models were used to infer trends and the estimates were compared with simulated point prevalence surveys (PPSs). Results More than 1.3 million antimicrobial administrations were analysed. There was significant daily and seasonal variation in overall consumption, which reduced annually by 1.77% (95% CI 0.50% to 3.02%). Relative consumption of meropenem decreased by 6.6% annually (95% CI −3.5% to 15.8%) following the expansion of the hospital antimicrobial stewardship programme. DOT and DDDs exhibited similar trends for most antimicrobials, though inconsistencies were observed where changes to dosage guidelines altered consumption calculation by DDDs, but not DOT. PPS simulations resulted in estimates of change over time, which converged on the model estimates, but with much less precision. Conclusions Electronic prescribing systems offer significant opportunities to better understand and report antimicrobial consumption in children. This approach to modelling administration data overcomes the limitations of using interval data and dispensary data. It provides substantially more detailed inferences on prescribing patterns and the potential impact of stewardship interventions.
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Rapid detection of NDM and VIM carbapenemase encoding genes by recombinase polymerase amplification and lateral flow-based detection. Eur J Clin Microbiol Infect Dis 2021; 40:2447-2453. [PMID: 33974185 DOI: 10.1007/s10096-021-04267-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 04/29/2021] [Indexed: 12/26/2022]
Abstract
Carbapenemase-producing organisms (CPOs) pose a serious clinical threat and rapid detection tools are essential to aid in patient management. We developed rapid and simple molecular tests to detect blaNDM-type and blaVIM-type carbapenemase genes using recombinase polymerase amplification (RPA) combined with a lateral flow detection. The tests could provide results in approximately 15 min when using DNA extracts, with limits of detection of 9.2 copies/μl for the blaNDM-type assay and 7.5 copies/μl for blaVIM-type assay, and successfully detected all isolates harbouring the carbapenemase encoding genes in a panel of 57 isolates. These RPA tests may be suitable for use in low-resource settings to tailor rapid implementation of infection control precautions and antibiotic stewardship.
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Detection of Epidemic Scarlet Fever Group A Streptococcus in Australia. Clin Infect Dis 2020; 69:1232-1234. [PMID: 30721938 DOI: 10.1093/cid/ciz099] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 01/30/2019] [Indexed: 11/13/2022] Open
Abstract
Sentinel hospital surveillance was instituted in Australia to detect the presence of pandemic group A Streptococcus strains causing scarlet fever. Genomic and phylogenetic analyses indicated the presence of an Australian GAS emm12 scarlet fever isolate related to United Kingdom outbreak strains. National surveillance to monitor this pandemic is recommended.
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A case for reduced frequency of CD4 count monitoring for children on combination antiretroviral therapy with consistently undetectable HIV viral load. HIV Med 2019; 20:e8-e9. [PMID: 30693658 DOI: 10.1111/hiv.12706] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Predicting Risk of Serious Bacterial Infections in Febrile Children in the Emergency Department. Pediatrics 2017; 140:peds.2016-2853. [PMID: 28679639 DOI: 10.1542/peds.2016-2853] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/03/2017] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Improving the diagnosis of serious bacterial infections (SBIs) in the children's emergency department is a clinical priority. Early recognition reduces morbidity and mortality, and supporting clinicians in ruling out SBIs may limit unnecessary admissions and antibiotic use. METHODS A prospective, diagnostic accuracy study of clinical and biomarker variables in the diagnosis of SBIs (pneumonia or other SBI) in febrile children <16 years old. A diagnostic model was derived by using multinomial logistic regression and internally validated. External validation of a published model was undertaken, followed by model updating and extension by the inclusion of procalcitonin and resistin. RESULTS There were 1101 children studied, of whom 264 had an SBI. A diagnostic model discriminated well between pneumonia and no SBI (concordance statistic 0.84, 95% confidence interval 0.78-0.90) and between other SBIs and no SBI (0.77, 95% confidence interval 0.71-0.83) on internal validation. A published model discriminated well on external validation. Model updating yielded good calibration with good performance at both high-risk (positive likelihood ratios: 6.46 and 5.13 for pneumonia and other SBI, respectively) and low-risk (negative likelihood ratios: 0.16 and 0.13, respectively) thresholds. Extending the model with procalcitonin and resistin yielded improvements in discrimination. CONCLUSIONS Diagnostic models discriminated well between pneumonia, other SBIs, and no SBI in febrile children in the emergency department. Improvements in the classification of nonevents have the potential to reduce unnecessary hospital admissions and improve antibiotic prescribing. The benefits of this improved risk prediction should be further evaluated in robust impact studies.
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Supporting decisions to increase the safe discharge of children with febrile illness from the emergency department: a systematic review and meta-analysis. Arch Dis Child 2016; 101:259-66. [PMID: 26718814 DOI: 10.1136/archdischild-2015-309056] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Accepted: 11/30/2015] [Indexed: 11/03/2022]
Abstract
BACKGROUND Despite fewer serious infections presenting to the children's emergency department (ED), hospital admissions of children with febrile illness have increased. We review evidence for the use of decision rules to increase the safe discharge of these children from the ED. METHODS A systematic review of prospective studies of decision rules for the discharge of children with febrile illness, and prediction rules for the diagnosis of serious infections in children presenting to ED. We reviewed the MEDLINE database, Cochrane Library and hand searched the bibliographies of related studies. The search was limited to the English language. RESULTS Thirty-three studies were identified. Fourteen reported low-risk criteria to rule out serious bacterial infection (SBI) in infants less than 3 months of age. In this group, clinical tools such as the Rochester and Philadelphia criteria support the safe discharge of low-risk infants without empirical antibiotics. Seventeen studies reported prediction rules in older children, though only four included children over 3 years. Two impact studies based upon multivariable prediction models failed to demonstrate any impact on rates of discharge from ED. CONCLUSIONS The use of clinical prediction models can improve discrimination between serious and self-limiting infections in children. The application of low-risk thresholds may help to rule out serious infections and discharge children from the ED without empirical antibiotics. A growing evidence base for prediction rules has so far failed to translate into validated rules to aid decision-making. Future work should evaluate decision rules in well designed impact studies, focusing on the need for hospital admission and antibiotic therapy.
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Etiology of childhood bacteremia and timely antibiotics administration in the emergency department. Pediatrics 2015; 135:635-42. [PMID: 25755240 DOI: 10.1542/peds.2014-2061] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/22/2015] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Bacteremia is now an uncommon presentation to the children's emergency department (ED) but is associated with significant morbidity and mortality. Its evolving etiology may affect the ability of clinicians to initiate timely, appropriate antimicrobial therapy. METHODS A retrospective time series analysis of bacteremia was conducted in the Alder Hey Children's Hospital ED between 2001 and 2011. Data on significant comorbidities, time to empirical therapy, and antibiotic susceptibility were recorded. RESULTS A total of 575 clinical episodes were identified, and Streptococcus pneumoniae (n = 109), Neisseria meningitidis (n = 96), and Staphylococcus aureus (n = 89) were commonly isolated. The rate of bacteremia was 1.42 per 1000 ED attendances (95% confidence interval: 1.31-1.53). There was an annual reduction of 10.6% (6.6%-14.5%) in vaccine-preventable infections, and an annual increase of 6.7% (1.2%-12.5%) in Gram-negative infections. The pneumococcal conjugate vaccine was associated with a 49% (32%-74%) reduction in pneumococcal bacteremia. The rate of health care-associated bacteremia increased from 0.17 to 0.43 per 1000 ED attendances (P = .002). Susceptibility to empirical antibiotics was reduced (96.3%-82.6%; P < .001). Health care-associated bacteremia was associated with an increased length of stay of 3.9 days (95% confidence interval: 2.3-5.8). Median time to antibiotics was 184 minutes (interquartile range: 63-331) and 57 (interquartile range: 27-97) minutes longer in Gram-negative bacteremia than in vaccine-preventable bacteremia. CONCLUSIONS Changes in the etiology of pediatric bacteremia have implications for prompt, appropriate empirical treatment. Increasingly, pediatric bacteremia in the ED is health care associated, which increases length of inpatient stay. Prompt, effective antimicrobial administration requires new tools to improve recognition, in addition to continued etiological surveillance.
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Commentaries on 'procalcitonin to initiate or discontinue antibiotics in acute respiratory tract infections' with a response from the review authors. ACTA ACUST UNITED AC 2014; 8:1372-4. [PMID: 23877945 DOI: 10.1002/ebch.1928] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
These are commentaries on a Cochrane review, published in this issue of EBCH, first published as: Schuetz P, Müller B, Christ-Crain M, Stolz D, Tamm M, Bouadma L, Luyt CE, Wolff M, Chastre J, Tubach F, Kristoffersen KB, Burkhardt O, Welte T, Schroeder S, Nobre V, Wei L, Bhatnagar N, Bucher HC, Briel M. Procalcitonin to initiate or discontinue antibiotics in acute respiratory tract infections. Cochrane Database of Systematic Reviews 2012, Issue 9. Art. No.: CD007498. DOI: 10.1002/14651858.CD007498.pub2.
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Novel biomarker combination improves the diagnosis of serious bacterial infections in Malawian children. BMC Med Genomics 2012; 5:13. [PMID: 22559298 PMCID: PMC3528639 DOI: 10.1186/1755-8794-5-13] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2012] [Accepted: 03/27/2012] [Indexed: 01/07/2023] Open
Abstract
Background High throughput technologies offer insight into disease processes and heightens opportunities for improved diagnostics. Using transcriptomic analyses, we aimed to discover and to evaluate the clinical validity of a combination of reliable and functionally important biomarkers of serious bacterial infection (SBI). Methods We identified three previously reported biomarkers of infection (neutrophil gelatinase-associated lipocalin (NGAL), granulysin and resistin) and measured gene expression using quantitative real-time PCR. Protein products related to the three transcripts were measured by immunoassays. Results Relative gene expression values of NGAL and resistin were significantly increased, and expression of granulysin significantly decreased in cases compared to controls. Plasma concentrations of NGAL and resistin were significantly increased in children with confirmed SBI compared to children with no detectable bacterial infection (NBI), and to controls (287 versus 128 versus 62 ng/ml and 195 versus 90 versus 18 ng/ml, respectively, p < 0.05). Plasma protein concentrations of NGAL and resistin were significantly increased in non-survivors compared to survivors (306 versus 211 and 214 versus 150 ng/ml, p = 0.02). The respective areas under the curve (AUC) for NGAL, resistin and procalcitonin in predicting SBI were 0.79, 0.80 and 0.86, whilst a combination of NGAL, resistin and procalcitonin achieved an AUC of 0.90. Conclusions We have demonstrated a unique combination of diagnostic biomarkers of SBI using transcriptomics, and demonstrated translational concordance with the corresponding protein. The addition of NGAL and resistin protein measurement to procalcitonin significantly improved the diagnosis of SBI.
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p50(cdc37) is a nonexclusive Hsp90 cohort which participates intimately in Hsp90-mediated folding of immature kinase molecules. Biochemistry 2000; 39:7631-44. [PMID: 10858314 DOI: 10.1021/bi000315r] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Hsp90 and p50(cdc37) provide a poorly understood biochemical function essential to certain protein kinases, and recent models describe p50(cdc37) as an exclusive hsp90 cohort which links hsp90 machinery to client kinases. We describe here the recovery of p50(cdc37) in immunoadsorptions directed against the hsp90 cohorts FKBP52, cyp40, p60HOP, hsp70, and p23. Additionally, monoclonal antibodies against FKBP52 coadsorb maturation intermediates of the hsp90-dependent kinases p56(lck) and HRI, and the presence of these maturation intermediates significantly increases the representation of p50(cdc37) and hsp90 on FKPB52 machinery. Although the native heterocomplex between hsp90 and p50(cdc37) is salt-labile, their dynamic interactions with kinase substrates produce kinase-chaperone heterocomplexes which are highly salt-resistant. The hsp90 inhibitor geldanamycin does not directly disrupt the native association of hsp90 with p50(cdc37) per se, but does result in the formation of salt-labile hsp90-kinase heterocomplexes which lack the p50(cdc37) cohort. We conclude that p50(cdc37) does not simply serve as a passive structural bridge between hsp90 and its kinase substrates; instead, p50(cdc37) is a nonexclusive hsp90 cohort which responds to hsp90's nucleotide-regulated conformational switching during the generation of high-affinity interactions within the hsp90-kinase-p50(cdc37) heterocomplex.
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Surgical antibiotic prophylaxis, patient morbidity, and cost reduction: a three-year study. DRUG INTELLIGENCE & CLINICAL PHARMACY 1987; 21:648-52. [PMID: 3608815 DOI: 10.1177/1060028087021007-818] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Twenty-five to 50 percent of all antibiotics prescribed for hospitalized patients are for prevention, not treatment, of infection. Procedures to institute rational, cost-effective utilization of these agents should have a significant impact on drug cost and pharmacy inventory. Several authors have described antibiotic cost reduction programs using pharmacy intervention. Unfortunately, measures that are successful in one institution may not be effective or appropriate in another. A three-year study was undertaken to examine the impact on physician prescribing of an infection control bulletin and formalized recommendation for antibiotic utilization. Patient records also were examined to determine if any change in antibiotic utilization would influence patient morbidity. Over the three examination periods there was a significant reduction in cost of prophylaxis in 7 surgical groups, and a trend toward cost reduction in 21 additional groups. Cost of prophylaxis also increased in other surgical groups. Cost reduction was associated with limited duration of prophylaxis and a shift toward use of first generation cephalosporin products. Patient morbidity did not differ significantly.
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