| Summary: | 碩士 === 國立嘉義大學 === 獸醫學系研究所 === 104 === Gallibacterium anatis is a relatively new genus of the family Pasteurellaceae. Existing clinical datas and recent experimental studies suggest that Gallibacterium anatis could cause lesions in the reproductive organs. Infected chickens can also show clinical symptoms such as depression, higher mortality in pullets, drop in egg production and deterioration of semen quality. Previous study showed that prevalence of Gallibacterium anatis in Denmark was up to 96 %. Researches from Europe and Asia also pointed that the frequency of treatment failure in relation to Gallibacterium flock infections seems to be a recurrent problem. To investigate the prevalence of Gallibacterium anatis in the southwestern part of Taiwan, we collected the laryngotracheal and cloacal swabs and used PCR technique to check the pooling samples from 77 flocks of healthy chickens. The result indicated the positive rate of Gallibacterium anatis was 53.25 % (41/77). There were no statistical significance in different species, age, area and production system. To assess the antimicrobial resistance, we collected 141 Gallibacterium anatis isolates to conduct antimicrobial susceptibility testing by disk diffusion method, disinfectant susceptibility testing by pour plate, and detected the tetracycline resistance genes and pathogenic genes. The results demonstrated high resistance to nalidixic acid (99.29 %), oxytetracycline (97.87 %), sulphamethoxazole/trimethoprim (97.16 %), tetracycline (90.78 %), amoxicillin (90.07 %), enrofloxacin (89.36 %), flumequine (88.65 %), streptomycin (87.23 %), tilmicosin (87.23 %) and doxycycline (83.69 %). Multidrug resistance was observed for 99.29 % of all isolates. Genotyping of tetracycline resistance determinants was performed with primers specific for tet(A, B, C, D, E, H, K, L, M, O). Strains positive for tet(B), tet(C), tet(K), tet(L) and tet(M) were identified. Tet(B) was the most common determinant identified. The result of pathogenic genes detection showed all of the isolates had gtxA gene, and 48.23 % isolates had FlfA gene. Except chloramide, Gallibacterium anatis was susceptible to disinfectant such as alcohol, iodine, glutaraldehyde, saponated cresol, ammonium bromide, sodium hydroxide and potassium hydrogen sulphate.
We suggested that Gallibacterium anatis does exist in Taiwan for a period of time and have a broad range of antimicrobial resistance. It’s not clear if Gallibacterium anatis really plays a role in Taiwan poultry industry, but we can still prevent and control the bacteria by cleaning, disinfection and biosecurity method.
|
|---|
