Is the GehD lipase from Staphylococcus epidermidis a collagen binding adhesin

The opportunistic human pathogen Staphylococcus epidermidis is the major cause of nosocomial biomaterial infections. S. epidermidis has the ability to attach to indwelling materials coated with extracellular matrix proteins such as fibrinogen, fibronectin, vitronectin, and collagen. To identify the proteins necessary for S. epidermidis attachment to collagen, we screened an expression library using digoxigenin-labeled collagen as well as two monoclonal antibodies generated against the Staphylococcus aureus collagen-adhesin, Cna, as probes. These monoclonal antibodies recognize collagen binding epitopes on the surface of S. aureus and S. epidermidis cells. Using this approach, we identified GehD, the extracellular lipase originally found in S. epidermidis 9, as a collagen-binding protein. Despite the monoclonal antibody cross-reactivity, the GehD amino acid sequence and predicted structure are radically different from those of Cna. The mature GehD circular dichroism spectra differs from that of Cna but strongly resembles that of a mammalian cell-surface collagen binding receptor, known as the alpha(1) integrin I domain, suggesting that they have similar secondary structures. The GehD protein is translated as a preproenzyme, secreted, and post-translationally processed into mature lipase. GehD does not have the conserved LPXTG C-terminal motif present in cell wall-anchored proteins, but it can be detected in lysostaphin cell wall extracts. A recombinant version of mature GehD binds to collagens type I, II, and IV adsorbed onto microtiter plates in a dose-dependent saturable manner. Recombinant, mature GehD protein and anti-GehD antibodies can inhibit the attachment of S. epidermidis to immobilized collagen. These results provide evidence that GehD may be a bi-functional molecule, acting not only as a lipase but also as a cell surface-associated collagen adhesin

677. Systematic Review of the Early Use Experince of Cefiderocol in Real World Practice

Abstract Background Gram-negative bacteria (GNB) with resistance to carbapenems is a growing global public health concern. The World Health Organisation have listed three priority GNB pathogens for the development of novel antimicrobial agents; Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacterales. The purpose of this systematic review (SR) was to report evidence on the use of cefiderocol (FDC), a siderophore cephalosporin, for patients with GNB infections in compassionate use or expanded access settings. Methods Searches were undertaken to identify relevant evidence up to December 2021. Two independent reviewers screened the records retrieved for relevance to the SR with disagreements adjudicated by a third reviewer. Patients receiving FDC in a compassionate use, expanded access setting or those with limited treatment options for the treatment of GNB infection were eligible. Eligible case reports and case series were assessed for quality using predefined tools and data were extracted (by a single reviewer with data checking performed by a second reviewer), tabulated and summarised. Results Forty-four studies (n=150 patients) were identified reporting the use of FDC; 3 case series studies and 41 case reports. The most commonly reported pathogens were P. aeruginosa (41.3%), A. baumannii (36.0%) and A. xylosoxidans (14.3%). The diagnoses varied widely across the included patients. All patients were administered FDC at a dose between 750 mg and 2 g per day on various schedules, adjusted for renal function for between one and six weeks. Clinical cure was reported in 137 patients using author-specified definitions with 74 patients (54.0%) reporting clinical cure and 18 (13.1%) reporting failure. Microbiological eradication was reported in 78 patients of whom 56 (71.8%) reported success, while 22 (28.2%) reported failure. For mortality (n=123) 80 patients (65.0%) remained alive at the end of treatment, while 43 (35.0%) died. Adverse event (AE) data was reported for 53 patients of whom 13 (24.5%) reported AEs, while 40 (75.5%) did not. See Table 1.0. Conclusion FDC is a promising therapy for patients with GNB infections with limited treatment options. Real world practice shows a high microbiological eradication rate and a small number of AEs. Disclosures Carlo Tascini, n/a, Shionogi: Grant/Research Support Aurelien Dinh, Professor of Infectious Disease, Shionogi: Advisor/Consultant|Shionogi: Board Member Christopher M. Longshaw, PhD, Shionogi: Employee Anita C. Fitzgerald, MPH, Shionogi: Shionogi commissioned York Health Economics Consortium of which I am an associate, to conduct the systematic review we are submitting to IDWeek Hannah Wood, BA MA, Shionogi: Shionogi commissioned York Health Economics Consortium of which I am an employee, to conduct the systematic review we are submitting to IDWeek Jacoby Vivien M. Patterson, MA Cantab, MB BChir, FFPH MD, Shionogi: Shionogi commissioned York Health Economics Consortium of which I am an associate, to conduct the systematic review we are submitting to IDW Deborah Watkins, MSc, Shionogi: Shionogi commissioned York Health Economics Consortium of which I am an employee, to conduct the systematic review we are submitting to IDWeek Katy Wilson, LLM, Shionogi: Shionogi commissioned York Health Economics Consortium of which I am an employee to conduct the systematic review we are submitting to IDWeek Karan Gill, Master of Science, Shionogi: Employee

Diversity of Clostridium difficile PCR ribotypes in Europe: results from the European, multicentre, prospective, biannual, point-prevalence study of Clostridium difficile infection in hospitalised patients with diarrhoea (EUCLID), 2012 and 2013

Clostridium difficile infection (CDI) is the major cause of infective diarrhoea in healthcare environments. As part of the EUCLID study, the largest C. difficile epidemiological study of its type, PCR-ribotype distribution of C. difficile isolates in Europe was investigated. PCR-ribotyping was performed on 1196 C. difficile isolates from diarrhoeal samples sent to the European co-ordinating laboratory in 2012–13 by 482 participating hospitals from 19 European countries. A total of 125 ribotypes were identified, of which ribotypes 027 (18.6%), 001/072 (11.2%) and 014 (7.0%) were the most prevalent. Distinct regional patterns of ribotype distribution were noted in Northern, Western, Southern and Eastern Europe. Of 596 isolates from patients with toxin-positive stools (confirmed CDI), ribotype 027 accounted for 27.8% of infections in patients aged 2–<65 years, but the prevalence decreased in those aged ≥65 years (14.3%) and further decreased in those aged ≥81 years (9.2%). The prevalence of ribotype 027 (but not other epidemic strains) was inversely proportional to overall ribotype diversity (R2=0.717). The EUCLID study highlights an increased diversity of C. difficile ribotypes across Europe compared with previous studies, with considerable inter-country variation in ribotype distribution. Continuous surveillance programmes are necessary to monitor the changing epidemiology of C. difficil

Replacement of Enterococcus faecalis by Enterococcus faecium as the predominant enterococcus in UK bacteraemias

Objectives To review temporal changes in the proportions of different Enterococcus species recorded in two UK bacteraemia surveillance systems. Antibiotic resistance trends were also considered. Methods We reviewed data for enterococci from 2001 to 2019 in: (a) the BSAC Resistance Surveillance Programme, which collected up to 7–10 bloodstream enterococci every year from each of 23–39 hospitals in the UK and Ireland and tested these centrally; and (b) PHE bacteraemia surveillance, using routine results from NHS microbiology laboratories in England. Results BSAC surveillance, based upon 206–255 enterococci each year (4486 in total), indicated that the proportion of Enterococcus faecium rose from 31% (212/692) in the period 2001–3 to 51% (354/696) in the period 2017–19, balanced by corresponding falls in the proportion of Enterococcus faecalis. PHE surveillance provided a larger dataset, with >5000 enterococcus reports per year; although its identifications are less precise, it too indicated a rise in the proportion of E. faecium. BSAC surveillance for E. faecium indicated no consistent trends in resistance to ampicillin (≥86% in all years), vancomycin (annual rates 19%–40%) or high-level resistance to gentamicin (31%–59%). Resistance to vancomycin remained <4% in E. faecalis in all years, whilst high-level resistance to gentamicin fell, perhaps partly reflecting the decline of two initially prevalent gentamicin- and ciprofloxacin-resistant clones. Conclusions Both surveillance systems indicate a growing proportion of E. faecium in enterococcal bloodstream infections. This is important because fewer therapeutic options remain against this frequently multiresistant species than against E. faecalis

Application of the hollow fibre infection model (HFIM) in antimicrobial development: a systematic review and recommendations of reporting

Item does not contain fulltextOBJECTIVES: This systematic review focuses on the use of the in vitro hollow fibre infection model (HFIM) for microbial culture. We summarize the direction of the field to date and propose best-practice principles for reporting of the applications. METHODS: Searches in six databases (MEDLINE®, EMBASE®, PubMed®, BIOSIS®, SCOPUS® and Cochrane®) up to January 2020 identified 129 studies meeting our inclusion criteria. Two reviewers independently assessed and extracted data from each publication. The quality of reporting of microbiological and technical parameters was analysed. RESULTS: Forty-seven out of 129 (36.4%) studies did not report the minimum pharmacokinetic parameters required in order to replicate the pharmacokinetic profile of HFIM experiments. Fifty-three out of 129 (41.1%) publications did not report the medium used in the HFIM. The overwhelming majority of publications did not perform any technical repeats [107/129 (82.9%)] or biological repeats [97/129 (75.2%)]. CONCLUSIONS: This review demonstrates that most publications provide insufficient data to allow for results to be evaluated, thus impairing the reproducibility of HFIM experiments. Therefore, there is a clear need for the development of laboratory standardization and improved reporting of HFIM experiments

The Magnitude of Global Marine Species Diversity

Background: The question of how many marine species exist is important because it provides a metric for how much we do and do not know about life in the oceans. We have compiled the first register of the marine species of the world and used this baseline to estimate how many more species, partitioned among all major eukaryotic groups, may be discovered. Results: There are ∼226,000 eukaryotic marine species described. More species were described in the past decade (∼20,000) than in any previous one. The number of authors describing new species has been increasing at a faster rate than the number of new species described in the past six decades. We report that there are ∼170,000 synonyms, that 58,000–72,000 species are collected but not yet described, and that 482,000–741,000 more species have yet to be sampled. Molecular methods may add tens of thousands of cryptic species. Thus, there may be 0.7–1.0 million marine species. Past rates of description of new species indicate there may be 0.5 ± 0.2 million marine species. On average 37% (median 31%) of species in over 100 recent field studies around the world might be new to science. Conclusions: Currently, between one-third and two-thirds of marine species may be undescribed, and previous estimates of there being well over one million marine species appear highly unlikely. More species than ever before are being described annually by an increasing number of authors. If the current trend continues, most species will be discovered this century

Metrics to assess the quantity of antibiotic use in the outpatient setting: a systematic review followed by an international multidisciplinary consensus procedure

Background The international Innovative Medicines Initiative (IMI) project DRIVE-AB (Driving Reinvestment in Research and Development and Responsible Antibiotic Use) aims to develop a global definition of ‘responsible’ antibiotic use. Objectives To identify consensually validated quantity metrics for antibiotic use in the outpatient setting. Methods First, outpatient quantity metrics (OQMs) were identified by a systematic search of literature and web sites published until 12 December 2014. Identified OQMs were evaluated by a multidisciplinary, international stakeholder panel using a RAND-modified Delphi procedure. Two online questionnaires and a face-to-face meeting between them were conducted to assess OQM relevance for measuring the quantity of antibiotic use on a nine-point Likert scale, to add comments or to propose new metrics. Results A total of 597 articles were screened, 177 studies met criteria for full-text screening and 138 were finally included. Twenty different OQMs were identified and appraised by 23 stakeholders. During the first survey, 14 OQMs were excluded and 6 qualified for discussion. During the face-to-face meeting, 10 stakeholders retained five OQMs and suggestions were made considering context and combination of metrics. The final set of metrics included defined daily doses, treatments/courses and prescriptions per defined population, treatments/courses and prescriptions per defined number of physician contacts and seasonal variation of total antibiotic use. Conclusions A small set of consensually validated metrics to assess the quantity of antibiotic use in the outpatient setting was obtained, enabling (inter)national comparisons. The OQMs will help build a global conceptual framework for responsible antibiotic use

In vitro activity of cefiderocol and comparators against Gram-negative bacterial isolates from a series of surveillance studies in England: 2014-2018.

OBJECTIVES The prevalence of Gram-negative bacteria (GNB) demonstrating extensive, multiple antimicrobial resistance is increasing in England, leaving few treatment choices. Cefiderocol is a novel siderophore cephalosporin approved in Europe for the treatment of aerobic GNB infections in adults with limited treatment options. We report pooled data for a clinical isolate set collected in England between 2014-2018. METHODS MICs were determined by broth microdilution according to International Organization for Standardization guidelines. Cefiderocol susceptibility was tested using iron-depleted cation-adjusted Muller-Hinton broth. Susceptibility rates were based on EUCAST breakpoints. In the absence of a species-specific breakpoint, pharmacokinetic/pharmacodynamic breakpoints were used. RESULTS Of 1886 isolates from England [74.1% Enterobacterales (18.7% Escherichia coli, 17.2% Klebsiella pneumoniae), 25.9% non-fermenters (18.4% Pseudomonas aeruginosa, 3.7% Acinetobacter baumannii)], 98.7% were cefiderocol-susceptible. Cefiderocol susceptibility in Enterobacterales (99.0%) was significantly (P < 0.01) greater than ceftolozane/tazobactam (94.3%), but similar to meropenem (99.3%) and ceftazidime/avibactam (99.4%). Overall, cefiderocol susceptibility (98.0%) in non-fermenters was significantly (P < 0.01) higher than comparators (range, 84.5-92.4%). Susceptibility to cefiderocol was 98.3-99.6% by infection source and was significantly (P < 0.01) greater than comparators for isolates from patients with nosocomial pneumonia (cefiderocol, 98.3%; comparators range, 79.8-93.8%). Excluding intrinsically meropenem-resistant Stenotrophomonas maltophilia, 47/1846 isolates (2.5%) were meropenem-resistant. A high proportion of meropenem-resistant P. aeruginosa were susceptible to cefiderocol (95.0%). All S. maltophilia isolates (40/40) were cefiderocol-susceptible. CONCLUSION A substantial proportion of clinical isolates from England, representing a wide range of pathogens across multiple infection sources, was cefiderocol-susceptible. Cefiderocol retained activity against meropenem-resistant strains

In vitro activity of cefiderocol and comparators against isolates of Gram-negative pathogens from a range of infection sources: SIDERO-WT-2014–2018 studies in Italy

ABSTRACT: Objectives: : Antimicrobial resistance, particularly carbapenem resistance, in Gram-negative pathogens poses a significant healthcare threat. Carbapenem resistance rates in Italy are among the highest in Europe. We report the in vitro activity of cefiderocol, a novel siderophore cephalosporin, and comparator antibiotics against Gram-negative isolates from Italy as part of the SIDERO-WT studies. Methods: : Isolates were collected between 2014 and 2018. Minimum inhibitory concentrations (MICs) were determined using International Organization for Standardization and EUCAST guidelines. Antimicrobial susceptibilities were interpreted using EUCAST breakpoints; pharmacodynamic/pharmacokinetic breakpoints were used if EUCAST breakpoints were not specified. Results: : The 2472 isolates [1545 (62.5%) Enterobacterales and 927 (37.5%) non-fermenters] represented a range of infection sources, including nosocomial pneumonia (902; 36.5%), complicated urinary tract infection (374; 15.1%), bloodstream infection (596; 24.1%), complicated intra-abdominal infection (257; 10.4%) and other infection sources (343; 13.9%). Cefiderocol was active against the majority of isolates, regardless of infection source (susceptibility, 94.2−97.3%). A high proportion of non-fermenters (97.6%) and Enterobacterales (95.6%) were cefiderocol-susceptible, although susceptibility was lower in Klebsiella pneumoniae (88.1%). Susceptibility to cefiderocol was significantly (P 8 mg/L), comprising 516/927 (55.7%) non-fermenters and 96/1545 (6.2%) Enterobacterales. Cefiderocol (499/516; 96.7%) activity was greater than colistin (440/516; 85.3%), ceftazidime/avibactam (123/516; 23.8%) and ceftolozane/tazobactam (89/516; 17.2%) in meropenem-resistant non-fermenter isolates. Conclusion: : Susceptibility to cefiderocol was significantly greater than meropenem, colistin, ceftazidime/avibactam and ceftolozane/tazobactam overall, regardless of infection source

In vitro activity of Cefiderocol against Gram-negative pathogens isolated from people with cystic fibrosis and bronchiectasis

ObjectivesGram-negative pathogens causing respiratory infection in people with cystic fibrosis and bronchiectasis are becoming progressively more resistant to conventional antibiotics. Although cefiderocol is licenced for the treatment of infections due to Gram-negative organisms, there are limited data on the activity of cefiderocol against pathogens associated with chronic respiratory diseases. The aim of this study was to determine the susceptibility of Gram-negative pathogens from cystic fibrosis and bronchiectasis to cefiderocol and comparator antibiotics.MethodsMinimal inhibitory concentrations (MICs) of cefiderocol and 15 comparator antibiotics were determined by broth microdilution against 300 respiratory isolates: Burkholderia spp., Stenotrophomonas spp., Achromobacter spp., Ralstonia spp. and Pandoraea spp., and used to calculate the MIC of each antibiotic required to inhibit 50% (MIC50) and 90% (MIC90) of isolates.ResultsThe MIC50 and MIC90 of cefiderocol for all 300 isolates tested was 0.25 and 32 mg/L, with 232 (77.3%) isolates having an MIC value ≤2 mg/L. In addition, cefiderocol demonstrated excellent activity against Stenotrophomonas spp. and Achromobacter spp. isolates, with 86.7% and 87.2%, respectively, exhibiting an MIC of 2 mg/L. Tigecycline also demonstrated good activity against all isolates with an MIC50 of &lt;0.5 mg/L.ConclusionsThese in vitro data demonstrated that cefiderocol had greater activity than most comparator antibiotics and could be an alternative treatment option for respiratory infection caused by these pathogens that has not responded to first-line therapy