Characterization of Ornithobacterium rhinotracheale (ORT) Isolated from Chickens Raised in Northern Provinces of Vietnam

Abstract

    In this study, we investigated some characteristics of Ornithobacterium rhinotracheale - ORT. Tracheal swabs, lung and airsacculitis were collected from 60 chickens showing clinical signs including loss of condition, gasping respirations and coughing for bacterial isolation and identification. The collected samples were cultured on Columbia Blood Agar Basal medium supplementing with 5% sheep blood or rabbit blood and 5 μg/ml Gentamycin, incubated at 37°C and 5% CO₂ for 48 hours. Small colonies were observed with some characteristics such as gray to grayish color, non-hemolysis, gram (-) staining, various lengths and rod shape. 30/60 colonies showed negative results in reaction with Catalase and Indol, but positive results in reaction with Oxidase, and were unable to grow on MacConkey medium. ORT isolates were able to resolve fructose, galactose, glucose, lactose, maltose and urease, but could not resolve sucrose and nitrate. ORT isolated strains were confirmed by PCR, showing approximate 784 bp-length products. The isolates were highly susceptible to amoxicillin/clavulanic acid and ampicillin while they were resistant to erythromycin, gentamycin, enrofloxacin and norfloxacin.