| In order to clarify the incidence of Swine colibacillosis and the serotypes, drug resistance, resistant gene of pathogenic porcine Escherichia coli in Hulunbeir area, 8 large scale pig farms were subjected to an incidence investigation of Swine colibacillosis. 108 strains of pathogenic porcine Escherichia coli were isolated and identified serotypes identifications. Addition, 18 kinds of antimicrobial was subjected to the drug sensitive test. A total of 10 kinds of resistance genes and class I integron of tetracyclines, macrolides and beta lactams from samples after incubation of the total bacteria and isolation and identification of 108 strains of pathogenic Escherichia coli was detected by the PCR method. At the same time, the micro ecological preparation EM original dew were adopted to the preventive test of piglet diarrhea and the Amikacin sulfate injection and Ciprofloxacin Lactate injection were adopted to the treatment test of artificial induced swine Escherichia coli. The main results are as follows.(1) 8 large scale pig farms in Hulunbeir area were subjected to Escherichia coli disease incidence survey by field investigation, access to information, pathological examination, and laboratory diagnosis. The results showed that the average incidence rate was 39.54% and the average mortality rate was 16.89%. The incidence of yellow and white scour of newborn piglets is primary(2) 108 strains of E.coli were isolated and identified of 136 samples form 8 large scale pig farms in Hulunbeir area. The isolated strains were adopted plate agglutination test and carried out on standard anti O antigen serum type test. The results showed that the unidentified serotypes were strains 11 and the 97 strains were identified as 8 different dominant serotypes were O8, O9, O60, O64, O115, O139, O149, O157, in which O8, O9, O149, O157.(3) 108 strains of E.coli isolated and identified were determined by the minimum inhibitory concentration of 18 antimicrobial agents by MH broth microdilution method refer to the CLSI standard and were analyzed drug resistance rate and multi drug resistance. The result showed that ampicillin, Pi La Shilling, tetracycline, nitrofurantoin, aztreonam the highest resistant rate, were all above 80%, and Amikacin, cefoxitin and cefotaxime, the lowest resistance rates were lower, in 6%. The isolates showed different degrees of resistance spectrum, which contain a total of 14 kinds of drug resistance spectrum. The least resistant isolates resistant to 3 kinds of antibacterial drugs, accounted for 1.9% and most of the resistant isolates resistant to 18 kinds of antibacterial drugs, accounted for 3.7%.(4) The tetracycline resistance genes, the macrolide resistance genes, and the beta lactam resistance genes from 136 samples after incubation of the total bacteria and isolation and identification of 108 strains of pathogenic Escherichia coli were detected by the PCR method. The results showed that the total bacterial genomic DNA samples was detected for tet A resistance gene, tet B, tet C, ermB, ermF, bla CTX-M, bla TEM and the detection rates were 97.06%, 94.12%, 85.29%, 22.06%, 20.59%, 56.62%, 92.65%. Pathogenic Escherichia coli isolates were tet A, tet B, erm B, bla CTX-M, bla TEM and the detection rates were 92.6%, 64.81%, 4.63%, 43.52%, 88.89%.(5) The class I integron of tetracyclines from 136 samples after incubation of the total bacteria and isolation and identification of 108 strains of pathogenic Escherichia coli was detected by the PCR technology. The results showed that detection rate of Int I in the total bacteria of 136 samples was 95.59%, and the detection rate of Int I in the disease of Escherichia coli isolates was 80.56%.(6) 40 healthy crossbred piglets with similar age and body weight were randomly divided into the group A(control group, n=20) and group B(experimental group, n=20). The piglets in group A were subjected to the normal management, and the piglets in group A were subjected to administration of oral 1:5 dilution with EM original dew. Continuous test of 35 d, in which daily records of A and B group of diarrhea, feed consumption and body weight. The results showed that diarrhea rate of B group was significantly lower than that of A group(P < 0.05) during 1 ~ 21 d of lactation. The difference of daily weight gain between group A and group B was significant(P < 0.05), the diarrhea rate and the feed to gain ratio of group B was lower than that in A group(P < 0.05) The results indicated that The micro ecological preparation EM original dew possess obvious effect to prevention of piglet diarrhea and improve the utilization rate of feed.(7) 40 healthy crossbred piglets with similar age and body weight were randomly and evenly divided into groups A,B, C and D, in which group A was the control group. Take the artificial induced by Escherichia coli infection of B, C, D, in which C, D two groups were treated with Amikacin sulfate injection and Ciprofloxacin Lactate injection treatment trials. Amikacin and ciprofloxacin lactate acid according per kilogram of body weight, 7.5 mg and 2.5 mg intramuscular injection administration respectively, and the treatment time interval of 0 h, 12 h 36 h, 60 h. Group B was control group only by artificial infection of swine Escherichia coli infection without treatment. The results indicated that Amikacin sulfate injection and Ciprofloxacin Lactate injection significantly improved artificial induced Escherichia coli disease.To sum up, 8 kinds of different serotypes including O8, O9, O149 and O157 were found in 108 strains of E.coli were isolated and identified of 136 intestinal contents form 8 large scale pig farms in Hulunbeir area. The isolated strains to 18 antimicrobial agents have different resistance and exists multiple drug resistance. A variety of resistance genes and class I integron of tetracyclines was detected from 136 samples after incubation of the total bacteria and isolation and identification of 108 strains of pathogenic Escherichia coli. The micro ecological preparation EM original dew was applied to perform the prevention trials of piglet diarrhea, and the results showed that the EM original dew can be effective in preventing diarrhea. Amikacin sulfate and ciprofloxacin against Escherichia coli disease curative effect significantly. This research provides a reference for veterinary clinical prevention and treatment of Colibacillosis in pigs. |
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