Enzymes expression of antioxidant protective function of microorganisms in process of develop antibiotic resistance

Abstract

Antibiotic resistance is one of the biggest threats in veterinary medicine that prevents effective treat animals with bacterial etiology diseases. The aim of the study was to research E.coli resistance to antimicrobial therapy. A different strain of E. coli 866 which is stable to complex antibiotic was used in the research. Primary cell cultures and cell cultures after 40 and 60 passages were used. Bacterial strains were cultured in pepted meat broth with growing concentration of bacteriostatic agents of Apramycin, Cefotaksim and .drug K‐2 is based on mixing of this two antibiotics. Threshold cycle is defined with software Rotor‐Gene 6000 (Australia). We have analyzed the relative level of gene expression with 2‐ΔΔCt method. Control group is primary cell cultures. Using of Cefotaksim after 40 passages gives results of insignificant decrease of peroxidase transcripts (0,33), small rise of catalase level (1,92) and iron superoxide dismutase (SOD Fe) (1,93) and strong growth of copper‐zinc superoxide dismutase (SOD) level (141,04). But after 60 passages we can see regress of peroxidase level (0,000019), catalase (0,0065) and copper‐zinc superoxide dismutase (SOD) level (0,0002). While level iron superoxide dismutase (SOD Fe) was high (3,61).Using of Apramycin for E. coli 866 after 40 passages gives results of notable fall of peroxidase level (0,000021), growth of catalase level (3,081), iron superoxide dismutase (SOD Fe) (1,14) and copper‐zinc superoxide dismutase (SOD) level (1,8). But after 60 passages we can see stable level of peroxidase (0,87) in relative to 40 passages. Decrease of catalase level (0,59), rise of copper‐zinc superoxide dismutase (SOD) level (2,58) and strong rise of iron superoxide dismutase (SOD Fe) (155,42).Study results of using K‐2 (complex of Apramycin and Cefotaksim) for E.coli 866 after 40 passages is significant growth of iron superoxide dismutase (SOD Fe) (113,77) and not so high rise of copper‐zinc superoxide dismutase (SOD) level (1,8).In the study of gene expression patterns of E.coli in process of develop antibiotic resistance by bacterial culture in MPB with growing concentration of bacteriostatic drugs during 60 passages appears changes of catalytic antioxidants in transcript representation. In conclusion superoxide dismutase (SOD) has the most visible changes. Relative level of gene expression of copper‐zinc superoxide dismutase is 141,04 with Cefotaksim after 40 passages and 155,42 with Apramycin after 60 passages. Relative level of iron superoxide dismutase (SOD Fe) is 113,77 and zinc superoxide dismutase (SOD Zn) – 88,035.Gene’s changes of catalytic antioxidant occur due to high survival by enzymes on antibiotic effects because of strong SOD antioxidant defense. Using of K‐2 leads to decrease the level of antibiotic resistance of E.coli 866.