The Antibiotic Sensitivity And Resistence Gene Of Riemerella Anatipestifer

The Riemerella anatipestifer infection is a contagious infectious disease, which mainly aggrieve ducks, turkeys and wild birds. Sometimes, it is also named as New duck syndrome, Anatipetifer syndrome, Infectious serositis , Pasteurella anatipestifer infection and so on.This disease always bring inflammation to the heart, liver, ballonet, brain and faltopian tube. It is a major disease confronting the duck industry all over the world, and it usually brings lots of economic losses to the duck industry because of high mortality and loss of weight. Usually, using antibiotics correctly is an effective way to cure this disease, but the RA come into being resistance to various antibiotics easily and quickly, so it is very important to investigate the drug-sensitivity and resistence gene.In this research, 22 strains of RA were isolated from sick ducks in Zhejiang province. Based on the results of the drug sensitivity test, the gene cassette-integron were examined by PCR to explain the producing and spread of drug-resistence on molecular level.22 strains of RA were identified by micro-morphology and biochemiscal characteristic assays. Their serotypes were identified also. 4 strains belong to serotype I, 14 strains belong to serotype II, only one strain belongs to serotype X and three strains belong to serotype XI. Based on this result, the serotype II play an important role in Zhejiang province.We did the drug-sensitivity test by Kirby-Baure method, and we find that the strains are sensitive to CMP,ERY,TET, resistant to KAN,AKN,P-G,NEO. Many strains isolated are resistant to more than four antibiotics.Design specific primers based on the known sequences of class I integron, investigate the distribution of the class I integron and the characterization of the resistance genes in 22 clinical Riemerella anatipestifers by PCR method. The PCR products were cloned and sequenced. From the analysis of these sequences, 22 strains of RA (100%) are positive for intI1 gene. Further more, the strains were amplified with primers of 5'CS and 3'CS which were set for amplifying the region of antibiotics resistance genes. Among 22 RA strains, an amplicon of 1048bp (In I-A) was yielded in only one strain, an amplicon of 2352bp (In I-B) was yielded in 21 strains. Sequencing data revealed that In I-A harbored aadA5 gene, In I-B harbored genes of aac6-II,catB3 and aadA1. The aadA5,aac6-II and aadA1 showing aminoglycoside resistance, catB3 conferring chloramphenicol resistance.