Studies of pathological alterations in fishes due to infection by some bacterial diseases of fayom province egypt

The present study dealt with two major aspects, the first one was the incidence percentages of variousisolates of micro-organisms in different kinds of fishand histopathological changes of the different organs of spontaneous infected fish, while the second wasconcerned with experiillental infection of the most predominill1t species in Anguilla Species to study theclinico ~~d histopathological pictures produced by such micro-organisms.The inCidence of bacterial pathogens varied according to t he kind of fish from 25.58 % in Bagrusb?,yadto 72.73 % in Mugil cephalus. Carp , Clarias,Tilapia, Anguilla, Mugil capitis and SOlea species gave isolation rate reached 66.67 % , 63.64 % 62.96 %,61. 54 % , 55.56 % and 52.94 % respectively. Generally 115 fish were posi ti ve for bacterial iSOlation outof the total 183 examined fish 62.86 %.Str. faeCalis, and Aerollionas hydr0phila were the most predominant pathogenic iSOlates 12.18 % and 7.82 %respecti ve.Ly , other bacteria recOvered in relati vely