In this study, Brucella abortus RB51 could be detected in the vaginal exudates of 5 out of 26 aborted cows following vaccination of three dairy cattle herds of 3810 animals including heifers and pregnant and non-pregnant cows by RB51 vaccine. Abortion associated with isolation of RB51 vaccinal strain from recently vaccinated cows in this study served as evidence that the vaccinal RB51 strain was the cause of abortion due to extensive bacterial multiplication and colonization in the uterus of vaccinated pregnant cows

In this study we used one reference Climson University (CU) strain and 3 virulent field strains isolated from naturally infected chicken and identified as P. Multocida. DNA was extracted from all strains and subjected to restriction endonuclease analysis, using EcoRI, HpaII and Hind III revealing that, great similarity between either the reference or local virulent field isolates. The obtained results indicated that the most differentiable restriction endonuclease enzyme was the Hind III, which showed different band patterns between different strains.

Twenty-five samples of canned fish (tuna and mackerel), frozen fish (mackerel and mazelli) as well as smoked fish (herring); five samples of each were randomly collected from different localities of Alexandria city. Collected samples were subjected to biogenic amine examination. Histamine and Tyramine were determined by HPLC. The highest average value (mg/100g) for histamine was 6.94 (canned tuna) and the lowest was 0.76 (Frozen Mazelli), the respective values for Tyramine were 1.63 (canned tuna) and 0.06 (frozen mazelli) mg/100g. For improvement the quality of raw fish (fresh sardine, 10 kg) during preparation the fresh sardine prior chilling or freezing was dipped into crude potato extract (as protease inhibitor) to reduce biogenic amines production. In order to test the effect of heat treatment on the concentration of the biogenic amines in fish (Frozen mackerel and sardine) were subjected to oven baking at 1506 C for 20 min. This showed high reduction in the percentage of biogenic amine production due to heat treatment. The public health significance of the biogenic amines as well as the suggested measures for improving the quality of produced products has been discussed

To analyze the major outer membrane proteins (OMPs) of the sensitive or resistant Pseudomonas aeruginosa strains, the OMPs were separated from the cellular elements by sarcosyl extraction method. OMPs profiles were conducted by SDSpolyacrylamide gel electrophoresis. Amoxicillin clavulanic acid (AMC) sensitive P. aeruginosa serotype K showed four protein bands; 35.713, 31.159, 26.107 and 22.869 KD. While AMC sensitive P. aeruginosa serotype H showed three bands of 35.713, 27.164 and 23.174 KD. Whereas AMC resistant P. aeruginosa serotype G, that was positive for the blaTEM gene by the PCR, modified its protein pattern. It has five protein bands of 52.142, 38.525, 30.690, 27.164 and 22.569 KD. These findings suggested that blaTEM gene and the outer membrane protein barrier are contributed to the resistance to amoxicillin clavulanic acid in P. aeruginosa. To determine a possible relationship between the resistance of P. aeruginosa and the production of antibodies against its outer membrane protein, antibodies against OMPs of AMC sensitive and resistant P. aeruginosa strains were prepared in mice and evaluated by ELISA. Our results showed that there was no association between immunogenicity of the outer membrane proteins and resistance of P. aeruginosa to antibiotics.

In the present study, 3 pooled proventricular homogenates were collected from 3 broiler flocks, of chicken 15 to 30 days old, from Monofia Governorate. The 3 flocks were suffered from low growth rate, poor feed conversion rate, uneven growth and increased mortalities. Necropsy of dead chickens revealed proventriculitis with increased proventriculus size. IBD viral antigen was detected in the pooled proventricular homogenate of each flock by AGPT using reference antibodies against IBDV and RT-PCR technique. No other viruses were detected; such as Reo virus, CAV, NDV, IBV and ALV-J. Further characterization of the IBDV isolates were conducted by RFLP assay on PCR products using MboI and BstOI restriction enzymes. Results demonstrate that the 3 IBDV isolates are identical in their RFLP pattern and related to the Del/E variant strain of IBDV.

Evaluation of amitraz against ticks and mites infestation in cattle and sheep in comparison with diazinon and deltamethrin was performed. Amitraz showed over 95 % inhibition of oviposition and hatching of laid eggs at dilution of 1:500 while diazinon and deltamethrin produced around 90 % inhibition of oviposition at the same dilution. Fed ticks were more susceptible for all tested acaricides than the unfed ticks, where amitraz reached its full effectiveness (100 % kill of fed and unfed) 2 weeks after application while diazinon and deltamethrin produced over 90 % at the same dilution. Spraying application of amitraz 12.5 % resulted in 100 % tick control by day 5 and the effect was maintained for further 28 days whereas diazinon and deltamethrin were fully effective by days 9 and 13, respectively and their efficacy were maintained for 16 and 20 days, respectively. Spraying application of amitraz 12.5 % produced 100 % efficacy as no live mites were found on day 17 and maintained in full effectiveness till day 33 where respraying was needed. In conclusion, amitraz produced rapid detachment of ticks from animals; its residual effect was long and protected animals from re-infestation for 29 days and was able to eradicate psoroptes mite infestation in sheep.

The development of thyroid glands of New-Zeland rabbits was studied in 28 fetuses (10-30 days) and 28 rabbits (3 days-5 years). The thyroid premordia appeared at the 12th day of gestation as 2 masses of cords and clumps of cells. The gland assumed the bilobed form with a narrow isthmus in between at the 18th day. Small primitive follicles with narrow empty lumina appeared in 14-day-old fetuses. True follicles were recorded in 20-22 days old fetuses while colloid was seen in the lumina of the central follicles at the 24th day. Light (C- or Parafollicular) cells were seen for the first time at the 12th day. With development of the follicles, C-cells appeared between the follicular cells and some of them come in contact with colloid. The ultimobranchial body (UBB) was observed in 20 days old fetuses close to the thyroid anlage and entered into its tissue at the 22nd day. Later on, it gave thyroid-like follicles or ultimobranchial cysts. With the electron microscope (EM) follicular cells of earlydeveloping fetuses were not yet differentiated. They contained few ill-developed rough endoplasmic reticulum (rER) and mitochondria. The organelles became well developed and the cells started to secrete colloid in full term fetuses. The maximum rate of secretory activity was achieved in the glands of adult rabbits. Changes in the thyroid glands during the postnatal life up to 5 years of age (age of senility) were followed up and described.

In this study, two methods for determination of formalin amount were applied on samples of inactivated vaccines representing local or foreign companies. The first method; matching method was conducted by using phenyl hydrazine while in the other method is; spectrophotometry phloroglucinol was used. Spectrophotometrical method was found more sensitive and more accurate than the matching one. At the same time, the spectrophotometry method could be used for determination of formalin in all inactivated vaccines either bacterial or viral vaccines.

The present study was designed in a trial to use serum replacement instead of the newborn calf serum in propagation of BHK-21 cell cultures with subsequent reducing the cost of foot and mouth disease (FMD) vaccine production. Two batches of BHK-21 cell culture were prepared where the medium of the first batch was supplemented with newborn calf serum while the medium of the second batch was supplemented with serum replacement. FMD virus was propagated 7 passages using BHK-21 cell culture. Both virus titration and complement fixation titer (CF) revealed that propagation of FMD virus in cell cultures supplemented with newborn calf serum yields a titre higher than that in case of cells supplemented with serum replacement. Also two batches of FMD inactivated vaccine were prepared from the virus propagated in the two-mentioned cell culture batches. Two groups of susceptible calves were vaccinated with these vaccines. Both of virus neutralization test (VNT) and enzyme linked immunosorbent assay (ELISA) revealed that higher antibody levels were induced in calves vaccinated with the vaccine prepared from cells supplemented with calf serum than those vaccinated with vaccine prepared from cells grown with serum replacement. BHK-21 cell culture supplement with newborn calf serum is most susceptible for FMD virus propagation yielding higher titer of the virus. Moreover, the growth pattern of the used cell culture was much better when the newborn calf serum was used.

In this study field application of RB51 vaccine combined with the policy of test and slaughter as well as application of hygienic measures for control of bovine brucellosis were carried out and evaluated in a dairy herd of cattle for two years. Serological examination of 1280 cattle using tube agglutination, buffered acidified plate antigen, Rose Bengal plate antigen and Rivanol tests revealed 240 (18.75%) positive animals with a previous history of abortion of 12 cows. Brucella melitensis biovar 3 could be isolated from tissue specimens of slaughtered cows. Animals that tested negative in the first examination were vaccinated with RB 51 vaccine with periodical examination every three weeks and slaughtering of positive cases. New positive cows continued to develop up to the 5th examination then three successive sero-negative tests were obtained with release of the farm from quarantine. Examination of animals 6,12,18 and 24 months post release of quarantine revealed 2, 3, 0 and one positive cases respectively the matter which clarified that the control of the outbreak using RB51 vaccine associated with policy of test and slaughter and application of hygienic measures showed some limitations.