Down-regulation of abaI, abaR, Bap and OmpA genes in Acinetobacter baumannii by ethanol extract of Glycyrrhiza glabra after toxicity assessment.

Acinetobacter baumannii is a pathogen that has caused rising concerns within healthcare facilities in recent years. As antibiotic overuse and resistance rise, natural remedies with the potential have received attention as antibiotics that might have fewer side effects and lower resistance. Glycyrrhiza glabra was used to investigate its effects on A. baumannii's quorum sensing and biofilm production abilities. In this study, the toxicity assessment of Glycyrrhiza glabra L. extract on rats, the phytochemical analysis and the quantitative measurement for the association of the biofilm reduction with the active components in the plant was determined. The results indicated ciprofloxacin and gentamicin were the most effective antibiotics and that various capabilities of biofilm-productions were demonstrated, only four percent of the samples established robust biofilm, while 40% to 56% demonstrated weak to moderate biofilm production, respectively. Phytochemical qualitative testing of ethanol leaf extracts from Glycyrrhiza glabra showed the existence of flavonoids, alkaloids, phenolic, tannic acid, and terpenoids, but no saponins. Assessment of toxicity revealed a low hazard, with an LD50 of 4.95 g/Kg. Our results showed that the extract's SICs elucidated a substantial quantitative decrease in biofilm production by the bacterial isolates, including the reference ATCC strain, which is known to be a potent biofilm producer. As a conclusion, biofilm creation in Acinetobacter baumannii has been shown to be greatly reduced by G. glabra extract.

Quercus infectoria gall extracts reduce quorum sensing-controlled virulence factors production and biofilm formation in Pseudomonas aeruginosa recovered from burn wounds.

BACKGROUND: Quercus gall extracts' ability to kill pathogens in vitro and even removal of chronic drug-resistant infections has been reported by several studies. The current investigation is focused on the action of extracts of Quercus infectoria gall in their sub-inhibitory concentrations on the corresponding bacterial behaviours instead of killing them. METHODS: The effect of gall extracts on the quorum sensing (QS) associated virulence of multiple drug resistant Pseudomonas aeruginosa recovered from burns wounds was studied. The influence of different extracts on the production of bacterial virulence and biofilm, and expression of the genes encoding quorum sensing and exotoxin A were investigated. Quorum sensing is a crucial regulator of virulence and biofilm development in Pseudomonas aeruginosa and other medical related microbes. RESULTS: Experiments to characterise and quantify Q. infectoria gall extracts impact on the quorum sensing networks of P.aeruginosa revealed that the expression of las, rhl, and exotoxin A (ETA) genes levels including the associated virulence were reduced by the extracts at their subinhibitory concentrations. CONCLUSIONS: The obtained results indicated that extracts of Q. infectoria galls fight infections either by their inhibitory constituents, which vigorously eradicate cells or by disruption of the pathogens quorum sensing system through weakening the virulence and bacterial coordination.