Journal of Clinical Care and Skills

en Isolation and Identification of Proteus mirabilis from clinical samples Using the VITEK-2 Automated System: A Phenotypic Evaluation Health Care Delivery Health Care Delivery پژوهشی اصيل Original Research Background: Proteus mirabilis is a clinically important Gram-negative opportunistic pathogen and a frequent cause of urinary tract infections, particularly in patients with indwelling urinary catheters. Reliable phenotypic identification is essential because several members of the genus Proteus share overlapping biochemical characteristics. The VITEK 2 automated system provides species identification through a standardized panel of biochemical reactions and a database-assisted interpretation. Objective: This study aimed to systematically characterize the phenotypic profile of clinical P. mirabilis isolates identified by the VITEK 2 GN card and determine the consistency and intra-species variability of the biochemical reactions underlying their identification. Materials and Methods: Over 150 urine samples twenty-three clinical Gram-negative isolates were identified using the VITEK 2 GN card. Identification probability, bionumbers, analysis time, and binary results of 47 biochemical reactions were obtained from the instrument reports. The isolates identified as P. mirabilis were further evaluated based on their individual biochemical profiles to determine the consistency and variability of the detected reactions. Results: VITEK 2 identified 18/23 isolates (78.3%) with probabilities ≥90%, while 5/23 (21.7%) were reported as “Unidentified Organism.” P. mirabilis was the most frequent identification (9/23, 39.1%); eight isolates showed 99% probability and one 96%, with a mean analysis time of 3.84 h. All P. mirabilis isolates were positive for H₂S, D-glucose, D-trehalose, phosphatase, coumarate, and O/129 resistance. ODC was positive in 8/9 (88.9%), whereas LDC was negative in all isolates. Urease and γ-glutamyl transferase were positive in 7/9 (77.8%) and 8/9 (88.9%), respectively, while tyrosine arylamidase and citrate utilization showed greater variability. Nine distinct bionumbers indicated limited biochemical variation among the isolates. Conclusion: The VITEK 2 GN card provided high-confidence identification of P. mirabilis and showed a consistent biochemical profile across the isolates. The ODC⁺/LDC⁻ pattern was a useful phenotypic feature, while variations in selected biochemical reactions indicated limited intra-species variability. Proteus mirabilis, VITEK 2, phenotypic identification, biochemical profile, GN card, ornithine decarboxylase. 1001 1008 http://jccs.yums.ac.ir/browse.php?a_code=A-10-437-1&slc_lang=en&sid=1 Hussain A. Naser 10031947532846006729 10031947532846006729 No Fatima B. Al-semaiil 10031947532846006730 10031947532846006730 No Manal D. Mohammed 10031947532846006731 10031947532846006731 No Basil A. Abbas basilabbas63@gmail.com 10031947532846006732 10031947532846006732 Yes