Evidence map›Paper›PMID 41934095›Full record

ArticleThe Journal of infectious diseases2026

Cefazolin Inoculum Effect and Cefazolin Microbiological Treatment Failure in Serious Methicillin-Susceptible Staphylococcus aureus Infections: A Multicenter Retrospective Cohort Study.

Mitchell A Jeffs, Nicole Li, Oluwalade Ogunkoya, D Brody Duncan, Carson K L Lo, Clayton W Hall, Ameera Nemer, Elaf Alzarnougi, Calvin Ka-Fung Lo, Emma B Monti and 6 more

Abstract readMulticenter Study
PubMed Full text at PMC Publisher
In one paragraph

Article in The Journal of infectious diseases, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.

0numbers the graph read from it
0cells of the map it votes in
2citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

2 citing papers in PubMed.

  1. Review
  2. Development of a rapid diagnostic test for the cefazolin inoculum effect in methicillin-susceptible Staphylococcus aureus: Cefinase disk direct (CDD) test.European journal of clinical microbiology & infectious diseases : official publication of the European Society of Clinical Microbiology · 2026
    Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

16 authors.

Mitchell A JeffsDepartment of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada.ORCID 0000-0002-0809-5038
Nicole LiDepartment of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada.ORCID 0009-0003-5155-5778
Oluwalade OgunkoyaDepartment of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada.
D Brody DuncanDepartment of Pathology and Molecular Medicine, Faculty of Health Sciences, McMaster University, Hamilton, Ontario, Canada.
Carson K L LoDivision of Infectious Diseases, Department of Medicine, McMaster University, Hamilton, Ontario, Canada.ORCID 0000-0002-1620-2868
Clayton W HallDepartment of Pathology and Molecular Medicine, Faculty of Health Sciences, McMaster University, Hamilton, Ontario, Canada.ORCID 0000-0002-4623-3534
Ameera NemerDivision of Infectious Diseases, Department of Medicine, McMaster University, Hamilton, Ontario, Canada.ORCID 0000-0002-0654-9374
Elaf AlzarnougiDivision of Infectious Diseases, Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
Calvin Ka-Fung LoDepartment of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, British Columbia, Canada.ORCID 0000-0003-3664-736X
Emma B MontiSchool of Medicine, Queen's University, Kingston, Ontario, Canada.
Thuwiba Al BalukiDivision of Infectious Diseases, Department of Medicine, Queen's University, Kingston, Ontario, Canada.ORCID 0009-0000-8134-1242
Zong Heng ShiDepartment of Pharmacy, North York General Hospital, Toronto, Ontario, Canada.ORCID 0009-0002-8094-0790
Xena X LiShared Hospital Laboratory, Toronto, Ontario, Canada.ORCID 0000-0003-1510-6310
Prameet M ShethDepartment of Pathology and Molecular Medicine, Queen's University, Kingston, Ontario, Canada.
Christopher T LohansDepartment of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada.ORCID 0000-0003-1094-0349
Anthony D BaiDivision of Infectious Diseases, Department of Medicine, Queen's University, Kingston, Ontario, Canada.ORCID 0000-0003-0448-9934

Funding

CIHRDepartment of Medicine
6 · The paper itself

Abstract

backgroundIt remains unclear if cefazolin inoculum effect (CzIE) translates to poorer clinical outcomes in patients with methicillin-susceptible Staphylococcus aureus (MSSA) infections who were treated with cefazolin.

methodsThis retrospective cohort study across 5 hospitals in Ontario, Canada, from 2021 to 2025 included adult patients who received cefazolin treatment for serious MSSA infection based on blood or deep sterile site culture growth. CzIE was defined as a ≥4-fold increase in cefazolin minimum inhibitory concentration to ≥16 μg/mL at a high inoculum based on broth microdilution assay. Patients were followed to 90 days. Primary outcome was all-cause mortality. Secondary outcome was microbiological treatment failure based on culture growth of MSSA after 1 week of cefazolin treatment. Potential confounders were adjusted using propensity score weighting, and a competing risk model for microbiological treatment failure was used to account for mortality as a competing event.

resultsOf 259 patients, 92 (35.5%) patients had an MSSA isolate that displayed CzIE. The 90-day mortality rate was 19/92 (20.7%) and 37/167 (22.2%) in the CzIE-positive and -negative groups, respectively, with adjusted risk difference of 0.6% (95% CI, -9.0% to 10.2%; P = .9060). Microbiological treatment failure occurred in 19/92 (20.7%) and 10/167 (6.0%) from the CzIE-positive and -negative groups, respectively, with adjusted subdistribution hazard ratio of 3.12 (95% CI, 1.38-7.08; P = .0065) in a competing risk model.

conclusionsCzIE was associated with a significantly increased risk of microbiological treatment failure. CzIE testing may be useful in guiding antibiotic treatment for serious MSSA infections.

Indexed as

Anti-Bacterial AgentsCefazolinStaphylococcal InfectionsStaphylococcus aureusAgedAged, 80 and overFemaleFirst Generation CephalosporinsHumansMaleMethicillinMicrobial Sensitivity TestsMiddle AgedOntarioRetrospective StudiesTreatment FailureAnti-Bacterial AgentsCefazolinFirst Generation CephalosporinsMethicillinantibiotic treatmentcefazolin inoculum effectStaphylococcus aureus

Identifiers

PMID41934095
PMCPMC13271370

What OpenQuestion holds

Textmetadata
LicenceCC BY
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.