Identification and antimicrobial susceptibility testing (AST) are critical steps in the management of bloodstream infections. Our objective was to evaluate the performance of the Accelerate Pheno™ ...System, CE v1.2 software, for identification and AST of Gram-negative pathogens from positive blood culture bottles. A total of 104 bottles positive for Gram-negative bacteria collected from inpatients throughout our institution were randomly selected after Gram staining. The time-to-identification and AST results, and the raw AST results obtained by the Accelerate Pheno™ system and routine techniques (MALDI-TOF MS and VITEK®2, EUCAST guidelines) were compared. Any discrepant AST result was tested by microdilution. The Pheno™ significantly improved turn-around times for identification (5.3 versus 23.7 h;
p
< 0.0001) and AST (10.7 versus 35.1 h;
p
< 0.0001). Complete agreement between the Accelerate Pheno™ system and the MALDI-TOF MS for identification was observed for 96.2% of samples; it was 99% (98/99) for monomicrobial samples versus 40% (3/5) for polymicrobial ones. The overall categorical agreement for AST was 93.7%; it was notably decreased for beta-lactams (cefepime 84.4%, piperacillin-tazobactam 86.5%, ceftazidime 87.6%) or
Pseudomonas aeruginosa
(71.9%; with cefepime 33.3%, piperacillin-tazobactam 77.8%, ceftazidime 0%). Analysis of discrepant results found impaired performance of the Accelerate Pheno™ system for beta-lactams (except cefepime) in
Enterobacteriales
(six very major errors) and poor performance in
P. aeruginosa
. The Accelerate Pheno™ system significantly improved the turn-around times for bloodstream infection diagnosis. Nonetheless, improvements in the analysis of polymicrobial samples and in AST algorithms, notably beta-lactam testing in both
P. aeruginosa
and
Enterobacteriales
, are required for implementation in routine workflow.
The incidence of campylobacteriosis has substantially increased over the past decade, notably in France. Secondary localizations complicating invasive infections are poorly described. We aimed to ...describe vascular infection or endocarditis caused by Campylobacter spp. We included 57 patients from a nationwide 5-year retrospective study on Campylobacter spp. bacteremia conducted in France; 44 patients had vascular infections, 12 had endocarditis, and 1 had both conditions. Campylobacter fetus was the most frequently involved species (83%). Antibiotic treatment involved a β-lactam monotherapy (54%) or was combined with a fluoroquinolone or an aminoglycoside (44%). The mortality rate was 25%. Relapse occurred in 8% of cases and was associated with delayed initiation of an efficient antimicrobial therapy after the first symptoms, diabetes, and coexistence of an osteoarticular location. Cardiovascular Campylobacter spp. infections are associated with a high mortality rate. Systematically searching for those localizations in cases of C. fetus bacteremia may be warranted.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Toxigenic Clostridioides difficile infection (CDI) is a high concern because of its increasing prevalence, among both nosocomial infection and community-acquired infection contexts. A total of 1320 ...prospective stool samples collected on FecalSwab™ (Cary-Blair medium) were screened using BD Max™ CDIFF assay (BDM). Results were compared to the routine algorithm including immunochromatographic testing for glutamate dehydrogenase (GDH) and toxin A/B (tox) using C. DIFF QUIK CHEK COMPLETE® followed by Xpert C. difficile assay in case of GDH+/tox- results. The prevalence of toxigenic C. difficile was estimated to 5.3% (n=70/1320) using the routine algorithm but to 7.4% (n = 98/1320) using BDM. The overall agreement between BDM and the routine algorithm was 97.4%. After resolution of discrepant results between BDM and the algorithm using Xpert C. difficile assay (unless already perform) and toxigenic culture performed by the French National Reference Laboratory, the overall agreement was increased to 99.4%, demonstrating the excellent performances of the test.
We describe 2 cases of healthcare-associated Legionnaires' disease in patients in France hospitalized 5 months apart in the same room. Whole-genome sequencing analyses showed that clinical isolates ...from the patients and isolates from the room's toilet clustered together. Toilet contamination by Legionella pneumophila could lead to a risk for exposure through flushing.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
To describe two linezolid-resistant MRSA strains carrying the cfr(B) gene detected in the French National Reference Centre for staphylococci.
Two linezolid-resistant MRSA strains isolated from cystic ...fibrosis patients in two different French hospitals in 2017 and 2019 were examined to explore the mechanisms of linezolid resistance. Antimicrobial susceptibility was tested using broth microdilution and gradient strips. The genetic determinants of linezolid resistance were assessed by a multiplex PCR targeting cfr/cfr(B), optrA and poxtA genes, by amplification and sequencing of individual 23S rRNA genes and by WGS using both Illumina and Nanopore technologies.
The two MRSA strains were resistant to linezolid but susceptible to tedizolid, and PCR-positive for cfr/cfr(B). The WGS analysis indicated that they belonged to two different STs (ST8-MRSA-IV and ST5382-MRSA-IV) and that they both harboured the cfr(B) gene on the same 9.7 kb Tn6218-like chromosomal transposon, a finding only previously reported in Enterococcus sp. and Clostridioides difficile.
To the best of our knowledge, this is the first description of the presence of cfr(B) in staphylococci, more specifically in linezolid-resistant MRSA strains. This finding illustrates the risk of horizontal intergenus transfer of oxazolidinone resistance genes in Staphylococcus aureus and highlights the need to monitor such emergence in this species.
An outbreak of Legionnaires' disease affected 18 people in Montpellier, a town of the south of France, between December 2016 and July 2017. All cases were diagnosed by a positive urinary antigen ...test. No deaths were reported. Epidemiological, environmental and genomic investigations (nested Sequence-Based Typing (nSBT) and whole genome sequencing) were undertaken. For the cases for which we had information, four had a new isolate (ST2471), one had a different new isolate (ST2470), one had a genomic pattern compatible with the ST2471 identified by nSBT (
A = 3), and one had a genomic pattern not compatible with two previous identified STs (
E = 6). The analysis conducted on the pool of an aquatic therapy center revealed seven isolates of
. Whole genome analysis confirmed the link between the environmental and clinical isolates for both ST2470 and ST2471. As the outbreak occurred slowly, with several weeks between new cases, it was not possible to immediately identify a common source. The sixth case was the first to report having aquatic therapy care. Of the 18 cases, eight had attended the aquatic therapy center and the other 10 were inhabitants who lived, worked or walked close to the center. The main cause for this outbreak was the lack of facility maintenance. This investigation highlights the risk to public health of aquatic therapy centers for users and nearby populations, and emphasizes the need for risk reduction measures with specific guidelines to improve health and safety in aquatic facilities.
While Legionella is a common cause of pneumonia, extrapulmonary infections like arthritis are scarce. Here, we describe a case of monoarthritis due to Legionella bozemanii, with no history of ...pneumonia. We provide a literature review of the 9 previously published Legionella arthritis and highlight a dichotomous epidemiology suggesting different physiopathological pathways leading to joint infection.
A 56-year old woman under immunosuppressive treatment by oral and intra-articular corticosteroids, methotrexate, and tocilizumab for an anti-synthetase syndrome was hospitalized for worsening pain and swelling of the left wrist for 3 days. Clinical examination showed left wrist synovitis and no fever. The arthritis occurred a few days after an accidental fall on wet asphalt responsible for a cutaneous wound followed by a corticosteroid intra-articular injection. Due to both the negativity of conventional culture of articular fluid and suspicion of infection, 16S rRNA and specific PCRs were performed leading to the identification of L. bozemanii. Legionella-specific culture of the articular fluid was performed retrospectively and isolated L. bozemanii. The empiric antibiotic therapy was switched for oral levofloxacin and rifampin and the patient recovered after a 12-week treatment.
We report a case of L. bozemanii monoarthritis in an immunosuppressed woman, following a fall on wet asphalt and intra-articular corticosteroid injection. The review of the literature found that the clinical presentation reveals the mode of infection and the bacterial species. Monoarthritis more likely occurred after inoculation in patients under immunosuppressive therapy and were associated with non-Legionella pneumophila serogroup 1 (Lp1) strains that predominate in the environment. Polyarthritis were more likely secondary legionellosis localizations after blood spread of Lp1, the most frequently found in pneumonia. In both settings, 16S rRNA and Legionella-specific PCR were key factors for the diagnosis.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Detection of
Legionella pneumophila
serogroup 1 urinary antigens is the most widely used technique for the diagnosis of Legionnaires’ disease (LD). The aim of this study was to evaluate the ...performance of the
Legionella K
-set® immunochromatographic test, in comparison with the BinaxNOW®
Legionella
urinary antigen card (UAC) on concentrated urine samples (US). A total of 250 concentrated US including 200 prospective US sent to the laboratory for urinary antigens’ testing and 50 frozen US from patients with confirmed LD were tested. Positive US were retested after boiling (5 min, 100 °C). Each US leading to discordant results between the two tests was further tested using Binax™
Legionella
EIA. Then, 10 additional positive non-concentrated US were tested using both tests. On concentrated US,
Legionella K
-set® test showed concordant results with that of BinaxNOW®
Legionella
. All negative US with BinaxNOW® were negative with
Legionella K
-set® test. For the 50 frozen US, all were positive with BinaxNOW® and 49 were positive with
Legionella
K-set®, all confirmed after boiling except 3 US which led to uninterpretable results with
Legionella K
-set®, due to a migration defect. Three of the 10 additional positive non-concentrated US were found negative with
Legionella K
-set® and only 1 US remained negative after concentration. All these positive non-concentrated US were positive with BinaxNOW®
Legionella
. The performance of the
Legionella
K-set® test is comparable to that of BinaxNOW®
Legionella
UAC, if performed on concentrated US.
•88% of Enterobacterales resistant to 3GC remained susceptible to ceftolozane-tazobactam.•Susceptibility to ceftolozane-tazobactam varies from 93% to only 13% for CTX-M and SHV-ESBL producers.•95.6% ...of Enterobacterales responsible for infections remained susceptible to ceftolozane-tazobactam.•Despite 99% CA, Etest® led to an underestimation of the ceftolozane-tazobactam MIC .
Ceftolozane-tazobactam (C/T) proved its efficacy for the treatment of infections caused by non-carbapenemase producing Pseudomonas aeruginosa and Enterobacterales. Here, we aimed to provide susceptibility data on a large series of Enterobacterales since the revision of EUCAST categorization breakpoints in 2020.
First, C/T susceptibility was determined on characterized Enterobacterales resistant to third generation cephalosporins (3GCs) (extended spectrum β-lactamase ESBL production or different levels of AmpC overexpression) (n = 213) and carbapenem-resistant Enterobacterales (CRE) (n = 259), including 170 carbapenemase producers (CPE). Then, 1632 consecutive clinical Enterobacterales responsible for infection were prospectively collected in 23 French hospitals. C/T susceptibility was determined by E-test® (biomérieux) and broth microdilution (BMD) (Sensititre™, Thermo Scientific) to perform method comparison.
Within the collection isolates, 88% of 3GC resistant strains were susceptible to C/T, with important variation depending on the resistance mechanism: 93% vs. 13% susceptibility for CTX-M and SHV-ESBL producers, respectively. Only 20% of the CRE were susceptible to C/T. Among CPE, 80% of OXA-48-like producers were susceptible to C/T, whereas all metallo-β-lactamase producers were resistant. The prospective study revealed that 95.6% of clinical isolates were susceptible to C/T. Method comparison performed on these 1632 clinical isolates demonstrated 99% of categorization agreement between MIC to C/T determined by E-test® in comparison with the BMD (reference) and only 74% of essential agreement.
Overall, C/T showed good activity against wild-type Enterobacterales, AmpC producers, and ESBL-producing Escherichia coli but is less active against ESBL-producing Klebsiella pneumoniae, and CRE. E-test® led to an underestimation of the MICs in comparison to the BMD reference.
Campylobacter spp. bacteremia is a severe infection. A nationwide 5-year retrospective study was conducted to characterize its clinical features and prognostic factors.
The study included patients ...with Campylobacter spp. bacteremia diagnosed in 37 French hospitals participating in the surveillance network of the National Reference Center for Campylobacters and Helicobacters, from 1 January 2015 to 31 December 2019. The goal was to analyze the effects of a delay of appropriate antibiotic therapy and other risk factors on 30-day mortality rates, antibiotic resistance, patient characteristics, and prognosis according to the Campylobacter species.
Among the 592 patients, Campylobacter jejuni and Campylobacter fetus were the most commonly identified species (in 42.9% and 42.6%, respectively). The patients were elderly (median age 68 years), and most had underlying conditions, mainly immunodepression (43.4%), hematologic cancers (25.9%), solid neoplasms (23%), and diabetes (22.3%). C. jejuni and Campylobacter coli were associated with gastrointestinal signs, and C. fetus was associated with secondary localizations. Among the 80 patients (13.5%) with secondary localizations, 12 had endocarditis, 38 vascular, 24 osteoarticular, and 9 ascitic fluid infections. The 30-day mortality rate was 11.7%, and an appropriate antibiotic treatment was independently associated with 30-day survival (odds ratio, 0.47 95% confidence interval, .24-.93; P = .03). The median efficient therapy initiation delay was quite short (2 days interquartile range, 0-4 days) but it had no significant impact on the 30-day mortality rate (P = .78).
Campylobacter spp. bacteremia mainly occurred in elderly immunocompromised individuals with variable clinical presentations according to the species involved. Appropriate antimicrobial therapy was associated with improved 30-day survival.
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