Diagnosis of Ornithobacterium rhinotracheale infection in chickens by ELISA.

Specific Ornithobacterium rhinotracheale (ORT) antibodies were determined in serum samples of 24 clinically infected broiler flocks of different ages (1-42 d) and 11 broiler-breeding flocks (at ages between 26-56 w) by ELISA. Two commercially available kits were separately assessed. The BioCheck ELISA kit was used for testing 363 serum samples representing 12 broiler flocks, where 74 samples (20.3 %) were found to be positive and 49 (13.5 %) were suspected. The IDEXX ELISA kit was used for testing 148 serum samples representing different 12 broiler flocks, where 115 samples (77.7 %) were positive. Testing of additional 70 serum samples from 5 broiler- breeder flocks, associated with drop in egg production (1-4.5 %) at different ages, by BioCheck ELISA kit revealed that 78.5 % of the samples were positive and 21.4% were suspected. On the other hand, 338 serum samples representing 6 broiler-breeder flocks, associated also with egg drop, showed a 84.6 % rate of positive reaction, when tested by IDEXX ELISA kit. Positive serology correlated well with the clinical manifestations and isolation of the organism, which substantiates the reliability of the used kits in diagnosis of the disease.

Interaction of oligodeoxynucleotides with mycobacteria: implications for new therapeutic strategies.

The use of synthetic oligonucleotides (ONs) to systematically address new pharmacologic targets in mycobacteria would enhance the introduction of new molecular targets for drug intervention. Oligonucleotides' mechanism of action allows researchers to pursue the importance of particular proteins without the requirement of having purified samples. For this approach to be effective, mycobacteria must be able to transport ONs to their cytoplasm, and if this is not the case, the agents must be otherwise delivered. In this report, we characterize the ability of phosphorothioate (PS) and phosphorodiester (PD) ONs to interact with both Mycobacterium smegmatis and Mycobacterium tuberculosis. In addition, the use of delivery enhancer compounds, ethambutol and PAMAM dendrimer, was evaluated on the ON-mycobacteria interaction. ON interaction was demonstrated to be concentration-dependent, suggesting a possibly active component of the oligonucleotide and bacteria interaction. ON interaction could be increased by the coincubation of the bacteria with the delivery adjuvants. Treatment with ethambutol or dendrimers (fourth generation) was demonstrated to increase ON interaction with both species of mycobacteria although not to the same extent. The results of these preliminary experiments indicate that through use of the proper delivery adjuvant, ON interactions with mycobacteria can be increased. These findings may have implications for probing future antimycobacterial therapeutic targets.