The Effect Of MSS On The Expression Of Resistant E. Coli AcrA MRNA And Biochemical Indicators In Infected Mice

The 15 strains of E.coli were suspected from the urine of patients, two isolates serotype were identified via culture and biochemical identify, serotype 2751:O148+O1; 2952 serotypes:O142+O26+ O13 separately. It was discovered that two E. coli strains were multiple drug resistant.Extraction MSS and MTYS, the resistances were measured using by tube dilution method, plate drilling method and so on, and chosen the best antibacterial prescription medicine after evaluated the MIC of resistant and standards strains (ATCC25922) of E.coli. The dosage of medicine prescription and toxic on E.coli were definited of mice.The 100 healthy mice are randomly divided into 5 groups:healthy group (A group), challeng group I (B group), challeng group II (C group), treatment group I (D group), treatment groupâ…¡(E group), all group were intraperitoneal injected 0.2ml bacterium fluid (about bacteria 1.6×10 CFU) except A group were intraperitoneal injected physiological saline. Since the 1st day of modeling, A, B and C group were irrigated 0.5mL physiological saline at 10 am for 7d, while D and E group were 0.5 mL MSS (1g/ml). In the 8th morning, all the mice were dissected to extract blood and detect biochemical indicators. While inoculated to the agar plates with the liver tissue, pick a single colony inoculated with E.c broth, determinate the range of antimicrobial susceptibility and separated drug-resistant E.coli after cultured 16-24h.The biochemical indicators had significant affect for mice infected resistant E.coli by MSS artificially: (1) MSS could promote the development of the immune organs--Spleen, liver and intestine, and enhance immunity; (2) The contents of ALT, AST, GLU could reduced obviously, and the contents of AMY, ALP and Ca were advanced obviously by MSS in serum, which could protect the liver and bravery, maintain balanced action; (3) MSS could reduce the damage to the kidney for various factors, enhance food intake and regulate microcirculation.MICs of isolated E. coli were detected, plasmids were extracted, acrA primers of efflux pump were designed according to the complete genome sequences of GeneBank(NC₀00913), and amplified by PCR and then sequenced. The fluorescent probe and small fragments of acrA were designed and cloned into pGM-T vector separately, which were transformed into DH5a. The positive clone recombinant plasmid were screened by X-gal and IPTG, identified by PCR and then as the standard of fluorescence quantitative. The total RNA were extracted and amplified by RT-PCR. The expression level of acrA in mRNA was detected by real-time fluorescence quantitative PCR. Results:(1) The gene of acrA was no mutations. (2) The expression (2751) of acrA in mRNA amount is 1016, higher than 2952. The expression of different resistant strains was different and each strain was higher than ATCC25922. The difference was very significant (p≤0.01). Conclusion:The expression of acrA mRNA was reduced by modified MSS and it had a high correlation with resistance.The results showed that MSS played a certain role in resistance and reversing for multi-resistant E. coli, and had a certain protective effect for animals and popularize value in clinic.