Affected 100 flocks revealed chronic whitish diarrhea. Consistent gross pathological lesions recorded were congestion and consolidation of lungs, hemorrhages in trachea, congestion and hemorrhages in liver, splenomegaly and necrotic foci on the kidneys, mortality in various flocks ranged from 3.7 -15% detailed isolation and biochemical studies revealed that Ornithobacterium Rhinotracheale was responsible for this wide spread respiratory problem. Five ORT isolate positive PCR implications were pre elicited to be the size of 784 bpfinally it was confirmed that sequence analysis of 16 sr RNA and ORT isolates from Gen bank with identified from 94% to 98%. Antibacterial sensitivity revealed that most of the isolates were sensitive to lincospectin (lincomycin + spectinomycin) and doxycycline. Many of the isolates showed resistance to kanamycin, norfloxacin, enrofloxacin, tetracycline and chloramphenicol. Experimental infection of broiler orally with ORT evoked respiratory signs with mortality reached 20% lesions of moderated saculitis mild tracheitis and unilateral pneumonia were recorded during the observation period. On other hand of broiler infected with ORT revealed that the infected and treated broiler were lower significance than infected and treated with lincospectin. The microscopical examination revealed pathological changes can be seen in lung, trachea, liver, spleen and brain.

The microorganisms which present on the clay soils, were studied. The result recorded that bacteria isolated from clay soils were identified Bacillus thuringiensis, E. coli, Pseudomonas, Klebsiella and Shigella. The B. thuringiensis is the highest bacteria causing mortality reached 100% to house fly and mosquitoes, while other bacteria causing 30%, zero%, zero% and zero% mortality for E. coli, Klebsiella, Pseudomonas and Shigellarespectively. Most strain of Bacillus thuringiensis isolates produce a typical crystal often heterogenous in size and shape. Extraction of total DNA from B. thuringiensis isolate for PCR analysis was done. All B. thuringiensis isolate were characterized by PCR. Parasporal bodies of B. thuringiensis isolates had biological activity when assayed againsthouse fly and mosquitoes. Field application of B. thuringiensis as toxic spray on poultry houses by using 2 x 10 3 c.f.u/m showed that mortality of mosquitoes reached 100% after 4 days. It can be concluded that Bacillus thuringiensis (BT) are bacteriocidal causing mortality reached to 100% after 4 days post-treatment with concentration of 2 x 10 3 cfu/ml. respectively. Most strain of Bacillus thuringiensis isolates produce a typical crystal