Pathological Changes Induced by Systemic Bacterial Infections of Layer Hens Suffered from Respiratory Signs

Abstract

Aims: to determine pathological changes of systemic bacterial infections with respiratory signs involvement in layer hens. Methods: Sixty sample of internal viscera (liver, lung, kidney, trachea, ovary, oviduct) 10 sample for each of them, belong to layer chickens were collected aseptically from different flocks suffering from respiratory signs, nervous signs, diarrhea, depression, reluctant move-ment and ruffled feathers. Results: High rate of bacterial infection reported in liver, (43.48%), in which S. aureus recovered from (26.08%), E. coli (13.04%) then, Klebsiella (4.35%). The second affected organ was the ovary (21.74%), in which S. aureus represent (8.7%), E. coli (4.35%)then, Klebsiella (8.7%). Kidney involvement represent (17.39%), in which S. aureus recovered from (8.7%), E. coli (4.35%)then, Klebsiella (4. 35%).Infection of Oviduct was reported as forth level, (8.7%), in which S. aureus represent (4.35%) followed by E. coli(4.35%).Lung and trachea located at the fifth level according to the rate of infection, (4.35%) for each one , both of them were infected with S.aureus . S. aureus develop resistant to 3out of 5 antimicrobial agent used which represent 60% ,which mean that the multidrug resistant trait bearing S. aureus was present in 60% of isolates for third generation cephalosporins ,Cefixime 5mcg, second generation of quinolone antibiot-ics on the other hand S. aureus was sensitive to Doripenem 10μg and Tetracycline30mcg.On the other hand E.coli and Klebsiella develop resistant to 3out of 5 antimicrobial agent used which represent 60% ,which mean that the multidrug resistant trait bearing E.coli was present in 60% of isolates for third generation cephalosporins ,Cefixime 5mcg, second generation of quinolone antibiotics as well as for Doripenem. Histopathological examination for liver revealed slight dilatation of sinusoid with obvious dis-persed apoptotic cells scattered associated with congestion for blood vessels. Degenerative changes for renal tubules as well as interstitial chronic inflammatory cells infiltration which is typical pathology for pyelonephritis. The ovary shows different level of follicles develop-ment and typical pathology for serous cyst adenoma formation. Luteal cysts with haemor-rhages and typical appearance of histiocytes laden with iron formation also reported. Conclusion: Liver was the main target for infection followed by ovary. S. aureus was the prominent agent followed by E. coli. S. aureus and E. coli have multidrug resistant trait for antibiotics commonly used in poultry medicine. The pathological changes range from apoptot-ic changes in liver, to degenerative changes of renal tubules and typical pathology for pyelo-nephritis in kidney. While in the ovary typical pathology was the formation of serous cyst ad-enoma.