The health benefits of antibiotics have been compromised in recent decades due to the rise of drug-resistant microbes, rendering many commonly used antibiotics increasingly ineffective and potentially hazardous. For treating Pseudomonas aeruginosa infections, evidence suggests that combined antibiotic therapy may be more effective than monotherapy.
This study aims to evaluate the antibiofilm and bactericidal effects of Conocarpus erectus plant extracts (CEP) against Pseudomonas aeruginosa, isolated from various hospitals and exhibiting multidrug resistance. Between September 2021 and January 2022, clinical specimens from 150 patients were collected. Out of these, 83 isolates grew on cetrimide culture medium after thorough cultivation on selective media, while the rest were identified using the VITEK 2 compact system.
Results revealed high resistance rates to Ceftriaxone (92.7%) and Amoxicillin-Clavulanic acid (89.2%), with Trimethoprim showing a resistance rate of 79.5%. To investigate the antibacterial properties of CEP, ten multidrug-resistant isolates were selected. Methanolic and aqueous extracts were prepared via Soxhlet extraction and maceration. Radical scavenging activity tests indicated that methanolic and aqueous CEP extracts (96.4% and 94.1% at 10mg/ml) outperformed artificial antioxidants like BHT (93.1%) and vitamin C (97.2%). The total phenolic content for aqueous and methanolic extracts was recorded at 51.6 mg/g and 65.6 mg/g, respectively. The methanolic extract exhibited superior bactericidal activity compared to the aqueous extract at a concentration of 100 mg/ml, with minimum inhibitory concentrations ranging from 8 to 32 mg/ml for methanolic CEP, while aqueous CEP ranged from 128 to 256 mg/ml. Checkerboard analysis revealed synergistic effects between methanolic CEP and Cefepime against several isolates.