Epidemiological studies on bovine mastitis in Egypt / Mohamed Fahmy Elsayed Morsy Azooz ; Supervised Hassan Mohamed Youssef , Safaa Aboelenin Elweakeel

Thesis (Ph.D.) - Cairo University - Faculty of Veterinary Medicine- Department of Internal Medicine and Infectious Diseases

The main aim of this study is to investigate and understand the molecular epidemiology of the most common pathogens (E coli, Staphylococcus aureus, Streptococcus uberis and staphylococcus haemolyticus) causing bovine mastitis in Egypt dairies, quantify and determine the prevalence of Salmonella Typhimurium and Staphylococcus aureus in the BTM, identifying the most important risk factors affecting the level of Staphylococcus aureus, Salmonella Typhimurium , SPC and SCC, in BTM in cattle Dairies, apply bioinformatics approach to explore more information about E coli TraT, Staphylococcus aureus hlg, Streptococcus uberis 16SrRNA, Staphylococcus haemolyticus tuf and Salmonella Typhimurium SopB proteins , applying Insilco analyses and computational approach for designing of TraT hlg , SopB B and T cells peptide based vaccines for controlling of Staphylococcus aureus, E coli mastitis and Salmonella Typhimurium infection in Cattle dairies and at last quantify and assess the annual herd economic losses caused by bovine clinical and SCM within the given large Egyptian dairy herds. The cow level prevalence of cattle mastitis was 57.1% (240/420). The cow level prevalence of clinical mastitis were (19%) (80/420). The cow level prevalence of sub-clinical mastitis based on CMT and SCC were (25.5%) (107/420) (160/420) 38% respectively. Out of 220 (160 sub-clinical and 60 active clinical mastitis) positive milk samples were collected from 20 cattle dairy farms 11, 18, 40 and 19 locally field isolates were detected and confirmed phenotypic by culturing, gram staining, biochemical and molecular identification to be in overall cow level prevalence of Staphylococcus aureus 11 (5%), Staphylococcus haemolyticus 18 (8.1%), E coli 40 (18.1%) and Streptococcus uberis 19 (8.6%). PCR identification of hlg gene of Staphylococcus aureus, E coli TraT, Streptococcus uberis 16SrRNA, Staphylococcus haemolyticus tuf genes isolates revealed TraT gene was found in all forty (100%) E coli isolates, (tuf) virulence gene was found in all (18) Staphylococcus haemolyticus isolates (100%). (hlg) gene was found in 11 (42.3%) Staphylococcus aureus isolates and (16SrRNA) gene was conserved in all Streptococcus uberis isolates

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