Tag Archives: Pseudomonas aeruginosa

Expression of LasR and LasI genes in quorum sensing system under the influence of iron oxide nanoparticles modified with silver surface structure in the clinical strain of Pseudomonas aeruginosa (Published)

This study was an attempt to examine expression of LasR and LasI genes in quorum sensing system under the influence of iron oxide nanoparticles modified with silver surface structure in the clinical strain of Pseudomonas aeruginosa. The participants of this study 51 samples of Pseudomonas aeruginosa bacteria (samples from different sources) such as Wounds, blood, urine and sputum (from Milad Hospital) in January 2019 to May 2020. The steady development of antibiotic resistance in various bacteria poses a high-risk threat to the health of the global community. Activation of quorum sensing signaling and biofilm formation leads to antimicrobial resistance of pathogens, thus increasing the difficulty in treating bacterial diseases. In this study, 50 clinical samples of patients were prepared in Milad Hospital, Tehran. By confirmatory and differential tests, these samples were confirmed as strains of Pseudomonas aeruginosa. After obtaining the MIC of iron oxide nanoparticles, this concentration (MIC = 0.512) of the nanoparticles was applied to the bacteria. The effect of iron-oxide surface nanoparticles on bacterial pathogens and genes affecting it (LasI and LasR) was investigated. Therefore, in this study, the expression of LasR and LasI genes in quorum sensing system under the influence of iron oxide nanoparticles modified surface structure with silver was investigated in the clinical strain of Pseudomonas aeruginosa.The analysis of data revealed that In microbiological (phenotypic) studies, the effect of iron oxide nanoparticles on surface structure modified with silver led to the lack of growth of Pseudomonas aeruginosa. The expression of LasR and LasI genes was significantly reduced under the influence of iron oxide nanoparticles modified surface structure with silver.In this study,  the fidings that iron oxide nanoparticles modified by surface structure can be effective on preventing pathogens by Pseudomonas aeruginosa. Also, surface iron oxide modified silver nanoparticles have antimicrobial properties in inhibiting bacterial growth there are various that are applied through different mechanisms. Decreased expression of LasR and LasI genes causes our nanoparticles to inhibit the quorum sensing system. Therefore, this study proposes to investigate the synergistic effect of iron oxide nanoparticles with antibiotics and other genes from the quorum sensing system.

Citation: Mohammad Ali Zamirian1, Shohreh Zare Kariz (2022) Expression of LasR and LasI genes in quorum sensing system under the influence of iron oxide nanoparticles modified with silver surface structure in the clinical strain of Pseudomonas aeruginosa, European Journal of Biology and Medical Science Research, Vol.10, No.2, pp.45-61

 

Keywords: Biofilm, Iron oxide nanoparticles Modified surface structure with silver, LasI gene, LasR gene, Pseudomonas aeruginosa, Quorum Sensing

Antibacterial Effect of Gongronema Latifolium Leaf Extracts On Selected Gram Positive and Negative Clinical Bacterial Isolates (Published)

This work was aimed at assaying the in-vitro effect of aqueous and ethanolic leaf extracts of Gongronema latifolium on Pseudomonas aeruginosa, Staphylococcus aureus, Klebsiella pneumoniae and Escherichia coli. Six (6) milimetre sterile discs were impregnated with the aqueous and ethanolic extracts at different concentrations ranging from 6.25mg/mL to 100mg/mL. The test organisms were spread evenly on Mueller Hinton agar plate and the discs were aseptically placed on them. The sensitivity plates were incubated at 37ºC for 24 hours. All the test organisms showed sensitivity to both aqueous and ethanolic leaf extracts of Gongronema latifolium. The zones of inhibition were concentration dependent, ranging from 2.0mm to 10.8mm for aqueous extract and 2.0mm to 8.3mm for the ethanolic extract. Comparison of the zones of inhibition produced by the two extracts showed that there is no statistical difference (P > 0.05) between aqueous and ethanolic extracts. Staphylococcus aureus, Escherichia coli and Klebsiella pneumoniae had Minimum inhibitory concentration (MIC) of 6.25mg/mL, while Pseudomonas aeruginosa had MIC of 25mg/mL for the aqueous extract. The MIC was 3.125mg/mL, 6.25mg/mL, 6.25mg/mL and 25mg/mL for S. aureus, E. coli, K. pneumoniae and P. aeruginosa, respectively for the ethanolic extract. Gongronema latifolium extracts were also bactericidal in action. S. aureus, E. coli and P. aeruginosa all had Minimum bactericidal concentration (MBC) of 6.25mg/mL, while K. pneumoniae had MBC of 25mg/mL for the aqueous extract, while for the ethanolic extract, S. aureus, E. coli, K. pneumoniae and P. aeruginosa had MBC of 12.5mg/mL, 12.5mg/mL, 6.25mg/mL and 3.125mg/mL respectively. The data obtained from the study indicated that both the aqueous and ethanolic leaf extracts of Gongronema latifolium possess antibacterial properties. Therefore, the pharmaceutical industries should consider its usage for the production of novel antibiotics.

Keywords: : Antibiotic, Plants, Pseudomonas aeruginosa, Resistance, medicinal

Phyto-Microbial Degradation of Glyphosate in Riyadh Area (Review Completed - Accepted)

Greenhouse studies were conducted to determine the ability of plant Amaranth, Amaranthus caudate and two isolated bacterial strains from rhizosphere region for cleaning up glyphosate residues in soil and plants. The analytical study of the biodegradation of glyphosate was carried out in the laboratory conditions. Amaranth, Amaranthus caudate and two isolated bacterial strains namely Pseudomonas aeruginosa and Bacillus megaterium could degrade glyphosate in 5 days. These results suggested that phytoremediation could accelerate the degradation of glyphosate residues in plants and in rhizosphere region as well. Glyphosate had strong effect on bacterial DNA where many DNA bands were affected. This could be explained that the effect of herbicide glyphosate on the protein profile may reflex somehow DNA mutation occurred during the assimilation of those toxic compounds. Therefore, the alteration occurred in both DNA and protein profiles is considered a degree of tolerance that lead to DNA mutation to cope with the assimilation of this compound. Therefore, the phytoremediation way could be a promising tool in program is to protect public health and the environment by ensuring the safety and availability of herbicides and pesticide alternatives.

Keywords: Amaranthus caudate, Bacillus megaterium, Glyphosate, Phytoremediation, Pseudomonas aeruginosa