Commercial identification systems often fail to identify Providencia stuartii.

Area of Science:

• Clinical Microbiology
• Bacterial Identification
• Diagnostic Systems Evaluation

Background:

• Accurate identification of bacterial pathogens is crucial for effective patient treatment.
• Providencia species are increasingly recognized in clinical settings.
• Evaluation of commercial identification systems is essential for clinical laboratories.

Purpose of the Study:

• To assess the performance of widely used commercial identification systems in Europe for Providencia species.
• To compare the accuracy of manual and automated systems in identifying Providencia strains.
• To determine the necessity of supplementary tests for reliable Providencia identification.

Main Methods:

• Testing of 145 clinical isolates of Providencia strains.
• Evaluation of two manual systems (API 20E, Enterotube II) and three automated systems (Cobas-Bact, Sceptor System, Titertek-Enterobac-Rapid Automated System).
• Analysis of identification accuracy and misidentification rates for each system.

Main Results:

• P. alcalifaciens and P. rettgeri were accurately identified by all tested systems.
• P. stuartii identification without supplementary tests varied significantly by system (42.5% to 71.2%).
• Misidentification rates for P. stuartii were substantial with some systems, necessitating further testing.

Conclusions:

• Commercial identification systems exhibit limitations in accurately identifying Providencia stuartii.
• Supplementary conventional tube tests are recommended for reliable differentiation of P. stuartii from other Proteeae tribe members.
• Laboratories should be aware of system-specific performance variations for Providencia identification.