Prevalence of the cefazolin inoculum effect (CzIE) in nasal colonizing methicillin-susceptible <i>Staphylococcus aureus</i> in patients from intensive care units in Colombia and use of a modified rapid nitrocefin test for detection.

ABSTRACT: The cefazolin inoculum effect (CzIE) has been associated with poor clinical outcomes in patients with methicillin-susceptible Staphylococcus aureus (MSSA) infections. We aimed to investigate the point prevalence of the CzIE among nasal colonizing MSSA isolates from ICU patients in a multicenter study in Colombia (2019-2023). Patients underwent nasal swabs to assess for S. aureus colonization on admission to the ICU, and some individuals had follow-up swabs. We performed cefazolin MIC by broth microdilution using standard and high inoculum and developed a modified nitrocefin-based rapid test to detect the CzIE. Whole-genome sequencing was carried out to characterize BlaZ types and allotypes, phylogenomics, and Agr-typing. A total of 352 patients were included; 46/352 (13%) pat

SUBMITTER: Carvajal LP 

PROVIDER: S-EPMC11539226 | biostudies-literature | 2024 Nov

REPOSITORIES: biostudies-literature