Author(s)

Sumon Kumar Das^1,2, Afzal Sheikh^3,4*, Nikhat Ara², Suma Mita Biswas², Abhinandan Chowdhury¹, Fatimah Az Zahra¹, Chaman Ara Keya^1*

¹Department of Biochemistry & Microbiology, North South University, Dhaka, Bangladesh.
²Department of Microbiology & Immunology, Evercare Hospital, Dhaka, Bangladesh.
³Department of Biochemistry and Molecular Biology, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Dhaka, Bangladesh.
⁴Institute of Food Safety and Processing (IFSP), Bangabandhu Sheikh Mujibur Rahman Agricultural University, Dhaka, Bangladesh.

Objective: Increasing the emergence of Metallo-β-lactamase (MBL) producing gram-negative bacteria and their dexterous horizontal transmission demands rapid and accurate detection. This study was conducted to determine a suitable method to promptly detect MBL-producing gram-negative bacteria. Methods: A total of 103 gram-negative bacteria were identified from various clinical samples at a tertiary care hospital in Dhaka city. MBL producers were detected by two phenotypic methods, the Disk Potentiation Test (DPT) and the Double Disk Synergy Test (DDST) based on β-lactam chelator combinations where EDTA/SMA has been used as an inhibitor and Imipenem, Ceftazidime as substrates. Results: 103 isolates which were identified as Escherichia coli spp, Klebsiella spp, Pseudomonas spp, Acinetobacter spp, Proteus spp, Providencia spp were found to be multidrug-resistant in antibiogram test. Isolates showed complete resistance (100%) to Imipenem, Meropenem, and Amoxiclav. The highest carbapenem-resistant etiological agents were Acinetobacter spp 40 (38.8%) followed by Pseudomonas spp 27 (26.2%), Klebsiella spp 26 (25.2%), Escherichia coli 8 (7.8%), Proteus spp 1 (1%) and Providencia spp 1 (1%). DPT method detected significantly (p = 0.000009) a higher number of MBL-producers (Imipenem with 0.5 M EDTA n = 61, 59.2% & Ceftazidime with 0.5 M EDTA n = 56, 54.4%) compared to the DDST method (Imipenem -0.5 M EDTA n = 43, 41.7%, Imipenem – SMA n = 38, 36.9% & Ceftazidime -0.5 M EDTA n = 15, 14.6%). Conclusion: Pieces of evidence suggest that DPT is a more sensitive method than DDST and could be recommended for identifying MBL-producing bacteria in Bangladeshi hospitals for the proper management of patients, to reduce time constraints and treatment costs.

Disk Potentiation Test (DPT), Double Disk Synergy Test (DDST), Metallo-β-Lactamase (MBL), Sodium Mercaptoacetate (SMA), and Ethylenediaminetetraacetic Acid (EDTA)

Das, S. , Sheikh, A. , Ara, N. , Biswas, S. , Chowdhury, A. , Zahra, F. and Keya, C. (2023) Evaluation of Disk Potentiation Test (DPT) and Double Disk Synergy Test (DDST) for The Detection of Metallo-β-Lactamases (MBLs) in Clinical Isolates of Bangladesh. Advances in Infectious Diseases, 13, 609-626. doi: 10.4236/aid.2023.134050.