Clinical trial NCT03992703: Clinical Impact of Rapid AST Directly From Blood Cultures
Official title: Clinical Impact of Rapid Susceptibility Testing on MHR-SIR Directly From Blood Cultures
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Bacterial Infections
Keywords: Clinical impact
Bacteremia
Antibiotic
Blood cultures
Enterobacteriaceae
Staphylococcus aureus
Lead sponsor: Fondation Hôpital Saint-Joseph
Sponsor class: OTHER
First posted: 2019-06-20
Enrollment: 160
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Observational model: COHORT
Time perspective: RETROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Patient with a positive blood culture and whose antibiotic susceptibility test was performed on conventional Mueller-Hinton medium between July 1, 2015 and June 30, 2018

Brief summary: Bacteremia is defined as pathogenic bacteria presence in blood as evidenced by positive blood cultures. These bacteremia have significant consequences in terms of morbidity and mortality (ref. 1,2,3). They can lead to a state of septic shock that is life-threatening for the patient and must be treated as a matter of urgency. Any delay in treatment is detrimental to the patient. Management is based on prescription of probabilistic antibiotic therapy as soon as bacteremia is suspected.

At the Groupe Hospitalier Paris Saint Joseph (GHPSJ), as soon as a blood culture is known to be positive, the Mobile Clinical Microbiology Unit (UMMC) is notified in real time. The UMMC infectiologist, in consultation with the microbiologist, evaluates microbiological data and compares them with clinical data in order to prescribe probabilistic antibiotic therapy in the patient's bed. The possible adaptation of antibiotic treatment then depends on the results of antibiotic susceptibility test.

Early adaptation of antibiotic treatment to antibiotic susceptibility data, to reassess ineffective treatment or to reduce antibiotic therapy spectrum, significantly improves patient prognosis: it is therefore important that the laboratory makes antibiotic susceptibility test results available to the clinician as early as possible.

Detailed description: The standard method based on diffusion on agar medium on conventional CBM allows antibiotic susceptibility results the test to be rendered within 24 hours. Many so-called rapid methods (Accelerate PhenoTM system, VITEK 2 Rapid Identification and Susceptibility Testing System,...) have been developed to improve antibiotic susceptibility testing speed from positive blood cultures. However, these approaches are costly and not exhaustive in terms of antibiotic panels tested.

The Mueller-Hinton Rapid-SIR (MHR-SIR) i2a medium has been developed. It is an agar medium allowing an early reading of antibiotic susceptibility test due to contrasting agents presence in culture medium which facilitates antibiotic susceptibility test results reading in less than 8 hours on a majority of fast-growing bacteria, in particular Enterobacteriaceae and golden staphylococci.

A prospective evaluation of the Mueller-Hinton Rapid-SIR (MHR-SIR) medium's performance directly from blood cultures was conducted in GHPSJ laboratory and published in 2018 with very satisfactory results obtained in less than 8 hours with a correlation \> 97% compared to the standard MH method (Results published in DMID ref.5) at a very moderate cost of 5 euros for 16 antibiotics in free choice; The additional cost compared to the traditional MH is 20% or 0.4 euros per agar. In view of excellent results of the study, this technique has replaced the traditional MH technique in GHPSJ laboratory since January 2017, allowing UMMC to propose more quickly adaptations of probabilistic antibiotic therapy.

The use of the MHR-SIR medium has never been evaluated in a clinical context. The objective of this pioneering study is to routinely evaluate the rendering clinical impact of the rapid antibiotic susceptibility test MHR-SIR (i2a) after 8 hours of incubation directly from the blood cultures.

Eligibility criteria: Inclusion Criteria:

* Patient hospitalized in a clinical department of the Groupe Hospitalier Paris Saint-Joseph
* Patient for whom a blood culture and antibiotic susceptibility test have been prescribed in the event of suspected bacteremia
* Patient with a positive blood culture with enterobacteriaceae or Gram-positive cocci suggestive of Staphylococcus sp.
* Patient whose antibiotic susceptibility test was performed on conventional Mueller-Hinton medium between July 1, 2015 and December 31, 2016 or on rapid Mueller-Hinton medium between January 1, 2017 and June 30, 2018 (date of antibiotic susceptibility test)
* Adult patient (age \> 18 years)
* Patient with social care

Exclusion Criteria:

* Bacteremic patient with bacteria other than enterobacteriaceae or Gram-positive cocci suggestive of Staphylococcus sp.
* Patient objecting to use of their data for this research
* Patient under guardianship or curatorship (unless consent is provided)
* Patient deprived of liberty
* Patient under justice protection

Primary outcomes:
measure: Differences in average time between the prescribing physician's request for examination and the first change in prescribed probabilistic antibiotic therapy following the rendering of results between two groups of patients.
timeFrame: 6 months
Secondary outcomes:
measure: Percentage of patients with escalation and de-escalation of prescribed probabilistic antibiotic therapy
timeFrame: 6 months
measure: Average number of days of broad-spectrum antibiotic therapy
timeFrame: 6 months
measure: Average oral relay time for antibiotics
timeFrame: 6 months
measure: Intra-hospital mortality prevalence of infectious origin
timeFrame: 6 months
Other outcomes:
Locations:
city: Paris
country: France
facility: Groupe Hospitalier Paris Saint Joseph
state: Ile-de-France
Study officials:
affiliation: Fondation Hôpital Saint-Joseph
name: Jean-Claude NGUYEN VAN, Doctor
role: PRINCIPAL_INVESTIGATOR
References:
citation: Perillaud C, Pilmis B, Diep J, Pean de Ponfilly G, Vidal B, Couzigou C, Mizrahi A, Lourtet-Hascoet J, Le Monnier A, Nguyen Van JC. Prospective evaluation of rapid antimicrobial susceptibility testing by disk diffusion on Mueller-Hinton rapid-SIR directly on blood cultures. Diagn Microbiol Infect Dis. 2019 Jan;93(1):14-21. doi: 10.1016/j.diagmicrobio.2018.07.016. Epub 2018 Jul 31.
citation: Garnacho-Montero J, Gutierrez-Pizarraya A, Escoresca-Ortega A, Fernandez-Delgado E, Lopez-Sanchez JM. Adequate antibiotic therapy prior to ICU admission in patients with severe sepsis and septic shock reduces hospital mortality. Crit Care. 2015 Aug 27;19(1):302. doi: 10.1186/s13054-015-1000-z.
citation: Brun-Buisson C, Doyon F, Carlet J, Dellamonica P, Gouin F, Lepoutre A, Mercier JC, Offenstadt G, Regnier B. Incidence, risk factors, and outcome of severe sepsis and septic shock in adults. A multicenter prospective study in intensive care units. French ICU Group for Severe Sepsis. JAMA. 1995 Sep 27;274(12):968-74.
citation: Ferrer R, Martin-Loeches I, Phillips G, Osborn TM, Townsend S, Dellinger RP, Artigas A, Schorr C, Levy MM. Empiric antibiotic treatment reduces mortality in severe sepsis and septic shock from the first hour: results from a guideline-based performance improvement program. Crit Care Med. 2014 Aug;42(8):1749-55. doi: 10.1097/CCM.0000000000000330.