HPLC-UV was used to compare the major constituents of two Pelargonium × hortorum cultivars and Pelargonium sidoides root extract. It revealed the presence of catechin and gallic acid in high concentrations and the absence of umckalin in P. × hortorum root extracts. The antibacterial activity of these extracts was screened against 19 Pseudomonas aeruginosa clinical isolates. P. × hortorum root extracts showed the lowest MIC values (512–1024 µg/mL). This activity was concluded to be attributable to the high concentrations of catechin and gallic acid. The anti-biofilm activity of catechin, gallic acid, and their combination was examined by a crystal violet assay. The combination reduced the percentage of strong and moderate biofilm-forming isolates from 52.63% to 5.26%. The impact on lasI and lasR genes expression using qRT-PCR and simultaneous docking against LasR protein was explored. The combination downregulated lasI and lasR gene expression in eight and six P. aeruginosa isolates, respectively, and showed the greatest docking score. Additionally, the in vivo protection capability of this combination in infected mice showed enhancement in the survival rate. Our study revealed the potential biofilm and quorum-sensing-inhibitory activity of the catechin and gallic acid combination as a novel alternative to inhibit bacterial pathogenicity.

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One of the global requirements for controlling the occurrence of resistance to antimicrobial drugs is to understanding the resistivity profile of various clinical isolates. Therefore, this study aimed to deliver the indication of different resistant profiles of clinically isolated Enterobacteriaceae from different sources of samples from Khartoum state, Sudan, and to determine the prevalence rate of extended-spectrum beta-lactamase (ESBL), multidrug-resistant (MDR), extensively drug-resistant (XDR), and pandrug-resistant (PDR) bacteria. A total of 144 Gram-negative bacteria were collected from different sources (vaginal swab, urine, catheter tip, sputum, blood, tracheal aspirate, pus, stool, pleural fluid, and throat swab). Samples were subcultured and identified according to their cultural characteristics and biochemical tests. Antimicrobial susceptibility test was performed for twenty-four antibiotics from eleven categories against all isolated Enterobacteriaceae according to the recommendation of Clinical and Laboratory Standards Institute (CLSI). The result showed that out of 144 isolates, Escherichia coli and Klebsiella pneumoniae were predominant isolates with the percentage of 47.9 and 25%, respectively. The prevalence of ESBL was higher in K. pneumonia (38.9%) than E. coli (34.8%). All isolated E. coli were sensitive to nitrofurantoin and tigecycline. There was a high prevalence of MDR Enterobacteriaceae, and only one isolate was XDR, while PDR was zero for all isolated bacteria. Active antimicrobial-resistant (AMR) observation through constant data sharing and management of all stakeholders is crucial to recognize and control the AMR global burden. Also, effective antibiotic stewardship procedures would be applied to limit the unreasonable expenditure of antibiotics in Sudan.

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