ABSTRACT
This study was carried out on 120 sheep clinically have respiratory disorder and were slaughtered in different abattoirs and private farms in Gharbia governorate. Samples were taken from nasal discharges, tracheal swabs, lung tissue and lung abscess. Bacteriological examination revealed that 103, 36, 56 and 19 positive for bacterial growth with percentages [85.83%] [30.0%], [46.66%] and [51.83%] respectively from previously affected sites of sampels. In total out of 259 bacterial isolates. Concerning G+ve bacteria, Staphylococcus aureus was 51 [19.6%], Streptococcus pneumonae 14 [5.4%], Corynebacterium pyogens 9 [3.5%], Streptococcus pyogens 8 [3.1%], Micrococcus luteus 5 [1.9%], Staphylococcus epidermidis 4 [1.5%], Enterococcus fecalis 3 [1.1%] and Streptococcus durans. 2 [0.8%] while the G-ve bacteria were identefied as E.coli 63 [24.3%], Pasteurella multocida 43 [16.6%], Klbsiella pneumonae 25 [9.7%], Mannheimia heamolytica 13 [5.1%], Proteus. vulgaris 9 [3.4%], Pseudomonos aeruginosa 5 [1.9%], Citrobacter. spps 11 [1.5%] and Enterobacter aerogens. 1 [0.4%], some samples give 38 mixed infection with a percentage of [7.91%] the mixed organisms were 8 [15%], 5 [1.1%] 9 [7.5%] and 6 [5%] respectively from the different examined collected sampels. The serological identification of PasteureIIa. multocida revealed that 27 [62.6%] were had capsular serotyped A, out of 43 samples +ve of Past. multocida, The Pathogenicity test for recovered Past. multocida isolates in mice indicated that most isolates were pathogenic [60 - 100%]. Sensitivity test revealed that the most isolates were highly sensitive to Enrofloxacin, and Gentamicin, and were resistant to Streptomycin and Ampicillin