Performance comparison of BD Phoenix CPO detect panel with Cepheid Xpert Carba-R assay for the detection of carbapenemase-producing Klebsiella pneumoniae isolates.

BACKGROUND: We aimed to compare the performance of carbapenemase classification in carbapenem-resistant Klebsiella pneumoniae (CRKP) obtained using the BD Phoenix CPO Detect panel (CPO panel) and Cepheid Xpert Carba-R assays. We analyzed 55 CRKP strains from clinical specimens collected between November 2020 and November 2022. The CPO panel was used to detect both antibiotic susceptibility and phenotypic carbapenemase classes, while Xpert Carba-R was employed to identify KPC, NDM, VIM, OXA-48, and IMP genes. Due to the limited availability of molecular kits, we arbitrarily selected 55 isolates, identified as carbapenemase-producing according to the CPO panel and with meropenem minimum inhibitory concentration values > 8 mg/L. RESULTS: According to the Xpert Carba-R assay, 16 of the 55 isolates (29.1%) were categorised as Ambler Class A (11 of which matched CPO panel Class A identification); three isolates (5.5%) were identified as Class B and 27 isolates (49.1%) as Class D (in both cases consistent with CPO panel B and D classifications). A further eight isolates (14.5%) exhibited multiple carbapenemase enzymes and were designated as dual-carbapenemase producers, while one isolate (1.8%) was identified as a non-carbapenemase-producer. The CPO panel demonstrated positive and negative percent agreements of 100% and 85.7% for Ambler Class A, 100% and 100% for Class B, and 96.4% and 100% for Class D carbapenemase detection, respectively. CONCLUSION: While the CPO panel's phenotypic performance was satisfactory in detecting Class B and D carbapenemases, additional confirmatory testing may be necessary for Class A carbapenemases as part of routine laboratory procedures.

Evaluation of antioxidant films of chitosan with Aquilaria agallocha extract as packaging material.

In this study, the bark of the Aquilaria agallocha was extracted, and the phenolic content of A. agallocha extract was determined using high-performance liquid chromatography-diode array detector. The A. agallocha extract-chitosan edible films were prepared by using a different amount of A. agallocha extract (0, 1, 4, and 8 mL) and chitosan solution. Some physical properties of A. agallocha extract-chitosan edible films, water vapor permeability, solubility, swelling ratio, humidity ratio, thickness, scanning electron microscopy, and Fourier transform infrared spectroscopy analysis were investigated. The antibacterial activities, total phenolic content, and antioxidant capacity analysis of the A. agallocha extract-chitosan edible films were performed. The total phenolic content (0, 1, 4, and 8 mL of A. agallocha extract-chitosan edible films 0.92 ± 0.09, 1.34 ± 0.04, 2.94 ± 0.10, and 4.62 ± 0.10 mg gallic acid equivalent (GAE)/g film, respectively) and antioxidant capacity (0, 1, 4, and 8 mL of A. agallocha extract-chitosan edible films 52.61 ± 2.85, 104.28 ± 4.78, 304.30 ± 18.23, and 592.11 ± 0.67 mg Trolox equivalent (TE)/g film, respectively) of A. agallocha extract-chitosan edible films increased with the increase in the amount of extract. At the same time, the increase in the amount of antioxidant capacity improved the physical features of the films. The results of the antibacterial activity studies showed that all of the A. agallocha extract-chitosan edible films prevented bacterial growth from Escherichia coli and Staphylococcus aureus considering controlling group. PRACTICAL APPLICATIONS: To investigate the activity of antioxidant extract-biodegradable film, the A. agallocha extract-chitosan edible film had prepared. The results showed that A. agallocha extract-chitosan edible film was antioxidant and antibacterial properties and was used as food packaging material successfully.