The evaluation of pesticides on opportunistic in pseudomonas aeruginosa and its antibiotic resistance

Abstract

Nowadays, researchers have pay attention to the various effects of micro-pollutants in the environment. In the present thesis, I focused on the effect of pesticides on the growth and antibiotic resistance profile of Pseudomonas aeruginosa, an emerging opportunistic pathogen microorganism. Method: 5 ppm concentrations of three pesticides (glyphosate, S-metolachlor, and terbuthylazine) were used for the treatment of 5 clinical and environmental strains of P. aeruginosa. Optical density of the treated bacterial cultures was detected after 1, 3, 24, 48, and 120 h to determine growth curves. Antibiotic resistance against 10 chosen agents was tested by MIC test strips (Liofilchem) containing a quantitative gradient of antibacterial drugs. Pesticide degradation rate of the examined strains was determined by gas chromatography. Results: Glyphosate and S-metolachlor both could be utilized as nutrients by the examined strains; therefore in the examined concentration they did not inhibit the growth of P. aeruginosa irrespectively to the origin of the strain (clinical or non-clinical). By contrast, terbuthylazine might have a negative effect on P. aeruginosa and limits its growth, but the differences were not significant. P. aeruginosa strains could degrade the S-metolachlor around 34-54% and terbuthylazine around 21-54% in 5 days. In addition, glyphosate caused a significant increase of MIC values on cefepime and ticarcillin and decreased the MIC values on tigecycline. S-metholachlor and terbutylazine have slightly increased the resistance of P. aeruginosa to ticarcillin, too but no other changes were observed.

Nowadays, researchers have pay attention to the various effects of micro-pollutants in the environment. In the present thesis, I focused on the effect of pesticides on the growth and antibiotic resistance profile of Pseudomonas aeruginosa, an emerging opportunistic pathogen microorganism. Method: 5 ppm concentrations of three pesticides (glyphosate, S-metolachlor, and terbuthylazine) were used for the treatment of 5 clinical and environmental strains of P. aeruginosa. Optical density of the treated bacterial cultures was detected after 1, 3, 24, 48, and 120 h to determine growth curves. Antibiotic resistance against 10 chosen agents was tested by MIC test strips (Liofilchem) containing a quantitative gradient of antibacterial drugs. Pesticide degradation rate of the examined strains was determined by gas chromatography. Results: Glyphosate and S-metolachlor both could be utilized as nutrients by the examined strains; therefore in the examined concentration they did not inhibit the growth of P. aeruginosa irrespectively to the origin of the strain (clinical or non-clinical). By contrast, terbuthylazine might have a negative effect on P. aeruginosa and limits its growth, but the differences were not significant. P. aeruginosa strains could degrade the S-metolachlor around 34-54% and terbuthylazine around 21-54% in 5 days. In addition, glyphosate caused a significant increase of MIC values on cefepime and ticarcillin and decreased the MIC values on tigecycline. S-metholachlor and terbutylazine have slightly increased the resistance of P. aeruginosa to ticarcillin, too but no other changes were observed.