Predictive Factors of Cloxacillin Susceptibility in Primary Bacterial Spinal Infection

Area of Science:

• Infectious Diseases
• Clinical Microbiology
• Epidemiology

Background:

• Spinal infections pose significant treatment challenges, with antibiotic resistance complicating management.
• Cloxacillin resistance in Staphylococcus isolates is a growing concern in orthopedic infections.
• Identifying predictors for antimicrobial resistance is crucial for optimizing patient care.

Purpose of the Study:

• To identify predictive factors for cloxacillin susceptibility in patients with spinal infections.
• To determine factors associated with gram-positive bacteria exhibiting cloxacillin resistance and gram-negative bacteria as causative agents.
• To identify predictors of 1-year all-cause mortality in spinal infection patients.

Main Methods:

• Retrospective analysis of patient data from January 1, 1997, to December 31, 2021.
• Inclusion criteria: back pain with positive spinal bacterial culture or radiological evidence of infection and positive blood culture.
• Statistical analysis to identify predictive factors for resistance and mortality.

Main Results:

• 53.2% of isolates were Staphylococcus, with 40.4% resistant to cloxacillin.
• Lower globulin levels (<33.5 g/L), recent hospitalization, and nursing home residency predicted resistant gram-positive and gram-negative infections (P<.05).
• Higher red cell distribution width (RDW >16.1%) and Charlson Comorbidity Index (CCI) scores predicted 1-year mortality (P<.05).

Conclusions:

• Low globulin, recent hospitalization, and nursing home residency are key predictors for cloxacillin-resistant gram-positive and gram-negative spinal infections.
• Patients with these factors should consider broader-spectrum antibiotics beyond standalone cloxacillin.
• Elevated RDW and CCI scores are significant indicators of increased 1-year mortality risk in spinal infection patients.