Detection of Carbapenemase Producers and Inhibitory Activity of Pediococcus pentosaceus YTPP 02 against Carbapenemase-Producing Bacteria

Carbapenem resistance caused by carbapenemase enzymes is of serious public health concerns globally, resulting in limited options for effective treatment. Rapid detection and exploring new agents are urgently required. This study aims to detect carbapenemase producers and to investigate the antibacterial potential of Pediococcus pentosaceus YTPP 02 against carbapenemase-producing Acinetobacter baumannii and Klebsiella pneumoniae. The carbapenemase producers were detected by a Nitro-beta test (NBT), a novel and rapid method, as well as by a combined disc with resazurin assay (CRA), and multiplex PCR. P. pentosaceus was isolated from pickled white radish on the MRS agar + 1 % CaCO3. The 16s rDNA-based PCR and sequencing were used for species identification. The agar overlay assay, agar well technique, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were employed to determine antibacterial activity of P. pentosaceus. The NBT successfully detected carbapenemase in all 5 clinical isolates within 20 min, and they all were positive for metallo-β-lactamases in CRA techniques within 7 h. The multiplex PCR detected VIM in A. baumannii BUU 62715, co-presence of NDM and OXA-48 like genes in both K. pneumoniae strains and NDM in A. baumannii BUU 60056 and 30899. Both A. baumannii and K. pneumoniae isolates were resistant to carbapenems. The 16s rDNA sequencing indicated P. pentosaceus. This bacterium exhibited Gram-positive cocci in pairs and quadruplets. P. pentosaceus YTPP 02 showed antibacterial activity against A. baumannii BUU 62715 and K. pneumoniae BUU 10624, with an inhibition diameter of 19 mm. The cell-free supernatant demonstrated promising antibacterial activity against A. baumannii isolates, with inhibition zones ranging from 15.3 - 18.5 mm, and a MIC of 62.5 mg/mL. P. pentosaceus YTPP 02 showed promising antibacterial activity against carbapenemase-producing bacteria. This could be a good candidate for further study and development as a new agent for carbapenem-resistant bacteria. HIGHLIGHTS A Nitro-beta test was able to detect carbapenemase producers within 20 min. A combined disc with a resazurin chromogenic agar plate identified metallo-β-lactamases within 7 h. Multiplex PCR confirmed the presence of carbapenemase-encoding genes in clinical isolates. pentosaceus inhibited the growth of carbapenemase-producing A. baumannii and K. pneumoniae. GRAPHICAL ABSTRACT