The Isolation, Identification, Molecular Typing And Virulence Genes Detection Of Lung Pathogenic Escherichia Coli In Musk Deers

To isolate and identify lung pathogenic Escherichia coli from forest musk deer,94lung samples were collected and plated onto EMB agar media. Bacterial culture, biochemical assays,16S rRNA PCR and pathogenic test were used to identify isolates.30lung pathogenic Escherichia coli in forest musk deer were isolated and identified. All of the30isolates could cause mice dead. The death rate of mice was100%. According to the judging standard of Clinical and Laboratory Standwrds Instituet (CLSI), drugs resistance of30pathogenic isolates were tested using20common antibiotics. The results showed that30isolates had different antibiotic resistance. The highest resistance rate of5drugs was over93%, which were amoxicillin, tetracycline, sulfafurazol, ampicillin, and amoxicillin and clavulanate potassium. Antibiotic resistance to paediatric compound sulfamethoxazole tablets and streptomycin was up to80%. Antibiotic resistance to ampicillin/sulbactam, inlidixicacid, ciprofloxacin and gentamicin was up to50%. This study would provide methods for quickly identification of Escherichia coli and provide the basis for clinical medication.In order to research the genotype defferences of pathogenic Escherichia coli isolated in musk deers, both ERIC-PCR and PFGE were performed. The results showed that the homology of some isolates was poor by ERIC-PCR, while they were high by PFGE. For instance, the homology rate was38.2%of M.D.E.coli-2and M.D.E.coli-1by ERIC-PCR, but the rate was very high by PFGE. Comparing with two methods, ERIC-PCR electrophoresis pattern contained less band types and low resolution. However PFGE contained more band types. So PFGE was more suitable for the bacteria classification than ERIC-PCR. For exploring pathogenesis of30lung pathogenic Escherichia coli in forest musk deer,15pairs of virulence factors primers including adhesins(afa/drab, iha and sfa/focCD), iron acquisition (sitD ep.a, sitD chr. and iucDa), serum resistance (neuC, ompA, cvi/cva, traTa and issa) and toxins (sat and vat, astA, and cnfl/2) were chosen to detect virulence factors of isolates. Results showed that among the30lung pathogenic Escherichia coli in forest musk deer, ompA positive rate (80%) was higher than other genes, such as astA (43.33%) sat (36.67%), vat、traTa and issA (26.67%), vat (26.67%) and iucD (23.33%). While no Cnf1/2neuC, sitD ep.a, sfa/focCD, afa/drab, iha and sitD chr. cvi/cva were detected. Researches on virulence factors detection of lung pathogenic Escherichia coli in forest musk deer could establish some foundation for exploring pathogenesis of pneumonia in forest musk deer, and would provide basis on disease prevention.