Sepideh Ghasemshahi - Department of Microbiology, Payvand Clinical and Specialty Laboratory, Tehran, Iran
Mohammad Ahmadpor - Department of Microbiology, Payvand Clinical and Specialty Laboratory, Tehran, Iran
Azam Booskabadi - Department of Microbiology, Payvand Clinical and Specialty Laboratory, Tehran, Iran
Hadi Rezaei - Department of Microbiology, Payvand Clinical and Specialty Laboratory, Tehran, Iran
Behzad Poopak - Head of Payvand Clinical and Specialty Laboratory, Tehran, Iran
Mojdeh Hakemi-Vala - Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences (SBMU), Tehran, Iran

Background and Objective: Increasing of resistant bacteria is a major concern globally. The emergence of XDR gram-negative bacteria is a more serious problem due to treatment limitations. This study aimed to evaluate the frequency of extensively drug-resistant (XDR) gram-negative bacterial isolates in different clinical samples from Payvand Clinical and Specialty Laboratory, Tehran, Iran, for ۶ months by VITEK ۲ system. Materials and Methods: During March ۲۰۲۰-September ۲۰۲۰, different clinical samples were collected from patients referred to Payvand Clinical and Specialty Laboratory. Bacterial identification and antimicrobial susceptibility test (AST) were performed applying an automated VITEK ۲ system. The frequency of identified bacteria, their resistance to common antibiotics and also XDR bacteria were calculated and reported, respectively. Results: Overall, ۴۱۲۵ urine specimens, ۳۴ sputum samples, and ۱ tracheal aspirate tube were submitted to Payvand Laboratory during ۶ months. Of them, ۴۸۶ urine, ۳۲ sputum, and a tracheal aspirate tube samples were culture positive. Gram-negative isolated bacteria were included in this study. Based on AST, ۶۳.۳% of the isolated Klebsiella pneumoniae, ۱۰۰% of Pseudomonas aeruginosa, and all Acinetobacter baumannii isolates were susceptible to amikacin and colistin. Totally, ۳۱ XDR gram-negative bacteria, including: K. pneumonia (ssp. pneumonia (n=۲۰), and ozaenae (n=۲), Escherichia coli (n=۳), P. aeruginosa (n=۵), and A. baumannii (n=۱) were identified from ۱۸ urine samples, ۱۲ sputum specimens, and a tracheal aspirate tube.  Conclusion: The rate of XDR bacteria was high in the investigated laboratory in this study. Therefore, accurate screening and antimicrobial stewardship is recommended in different medical centers of Iran.

Automation, Drug resistance, Gram negative bacteria, antibiotics, اتوماسیون, مقاومت دارویی, باکتری های گرم منفی, آنتی بیوتیک ها