A Six-Month Survey of the Frequency of Extensively Drug-resistant Gram-Negative Bacteria by VITEK ۲ System in ۲۰۲۰

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.

Keywords:

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