Studies On Drug Resistance And Resistant Genes Of Gallibacterium Anatis Strains Isolated From Chickens In Different Localities

Gallibacterium anatis disease is mainly caused by Gallibacterium anatis resided in the upper respiratory and the lower genital tracts, but pathogenicity mechanism of Gallibacterium anatis has not been researched clearly. This research investigated in resistance of Gallibacterium anatis firstly, then plasmid-mediated resistant gene of Streptomycin and Sulfamethoxazole, cloning and sequence analysis of resistant gene of. Fluoroquinolones were researched. In order to investigate the resistance and resistant genes of this kind of bacteria conveniently, PCR method detecting resistant genes of Streptomycin and Sulfamethoxazole were researched.By the analysis of resistance results, Gallibacterium anatis strains are especially sensitive to Cefoperazone, Ceftriaxone and Cefepime; Gallibacterium anatis strains are also sensitive to Ampicillin, Cidomycin, Cyclomycin and Deoxycycline; Gallibacterium anatis strains are very resistant to Streptomycin, Sulfasulfonamide, Ciprofloxacin, Norfloxacin, Ofloxacin and Clindamycin. Primers were designed based on resistant genes of Streptomycin in Genbank, StrA, StrB and aadA were amplified from plasmid of Gallibacterium anatis. Primers were designed based on resistant genes of Sulfasulfonamide in Genbank, SulI and SulII were amplified from plasmid of Gallibacterium anatis. this result indicate that the resistance to Streptomycin and Sulfasulfonamide in Gallibacterium anatis is concerned with resistant genes of Streptomycin and Sulfasulfonamide, serious resistance to them in Gallibacterium anatis was caused through transmission of resistant plasmid probably.The nucleotide sequences of the quinolone resistance-determining regions of the gyrA and parC genes were amplified in Gallibacterium anatis through degenerate primers used in Haemophilus and Pasteurella successfully. Through analysis of nucleotide and amino acid sequence of the two genes, the results indicate Gallibacterium anatis is a genus with Pasteurella, and through nucleotide and amino acid sequence analysis of QRDR of Gallibacterium anatis,the results indicate that the resistance of many stains to fluoroquinolone was caused by mutations in gyrA and parC ,The mutations of GyrA were a serine to Phe or Tyr, The mutations of parC were a serine to Ile.In order to detect resistant genes of Streptomycin and Sulfamethoxazole quickly ,triplex PCR method that detect resistant genes StrA, StrB and aadA was established ,and duplex PCR method that detect resistant genes SulI and SulII was also established. Specificit , sensitivity , reproducibility and application experiments indicate the established two PCR methods were quick, sensitive and specific,it provide quick methods to detect resistance and resistant genes of Streptomycin and Sulfamethoxazole of Gallibacterium anatis ,it also provide new ways to resistant molecular epidemiology about Sulfamethoxazole of Gallibacterium anatis .