Enterotoxigenic Escherichia coli K99 is one of the dominant pathogens associated with diarrhea of calves. Immunoglobulin Y (IgY), has been used as an inexpensive alternative to antibiotics for the prevention and therapy of several bacterial infections. The study aimed to prepare IgY antibodies against E. coli K99 and to investigate its in vitro effectiveness. E. coli K99 was grown in the tryptic soy broth, and the bacterial sus-pension was inactivated by formaldehyde. Thirty White Leghorn hens allocated to control and treatment groups. 1 mL of the prepared bacterial suspension or sterilized physiological serum emulsified with Freund’ s complete adjuvant was injected at two weeks interval to the hens in treated or control group. The total IgY was purified with polyethylene glycol (PEG) 6000 from EGG YOLKs (EY). Purified IgY fractions were processed for protein concentrations by Bradford assay. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis was used to analyze purified IgY fractions. An indirect enzyme-linked immunosorbent as-say (ELISA) method was used to measure the specific IgY titers in serum and EY. The ability of non-specific and anti-E. coli K99 IgY antibody at 100 and 200 mg/mL concentration was evaluated by growth inhibition assay in vitro. According to the ELISA data, total IgY concentration in serum and EY of control was relatively constant, while increased in the treatment group (P<0. 05). The level of binding activity of specific IgY in serum and EY increased in immunized hens (P<0. 05). Specific IgY had the highest activity for bacterial inhibiting growth at the level of 200 mg/mL. These results suggested the prepared IgY antibod-ies could inhibit E. coli K99 in vitro growth.

Oxidative damage to membrane lipid is one of the prime events occurring in aging and other undesirable physiological processes. In this study experiments were performed on liposomes (prepared either from crude erythrocyte PHOSPHOLIPIDS or purified EGG YOLK phosphatidylcholine) as models of lipid bilayer portion of biomembranes. The effects of β-carotene, and phospholipid composition on peroxidation process, initiated by Fe2+, were studied. It was found that β-carotene does not show any noticeable antioxidant effect on the peroxidation process initiated by Fe2+ in liposomes prepared from erythrocyte phosphatides, whereas it effectively suppressed the same process in EGG YOLK phosphatidylcholine (EYPC). It is concluded that the anti-/pro-oxidant activity of β–carotene is also dependent on the membrane lipid composition and this may provide an explanation about the conflicting reports on its role in ordinary or promoted oxidation experiments.

This study was conducted to assess the physical and morphological characteristics of fresh, pre-freeze and post-thaw black Bengal buck (Capra hircus) semen processed in Tris-EGG YOLK-citrate-fructose-glycerol (TEYCFG) extender containing 4 different concentrations (2.5, 5, 7.5 and 10%) of EGG-YOLK. Ejaculates were collected once a week for eight weeks from six mature bucks (48 ejaculates) using an artificial vagina. It was found that a general decrease in values of pre-freeze and post-thaw semen parameters such as progressive sperm motility (%), live sperm (%), acrosomal integrity (%) and positive sperm (%) in the hypo-osmotic swelling (HOS) test, but an over-all increase in abnormal spermatozoa compared to fresh semen for extenders containing different concentrations of EGG-YOLK. Best values for all the semen parameters were obtained using extender with 2.5% EGG-YOLK. Of all EGG-YOLK concentrations, the 10% EGG-YOLK supplement caused the highest percentage of abnormal sperm, which was significant (P<0.05), compared to 2.5% and 5% EGG-YOLK containing extenders, but non-significantly (P>0.05) different compared with 7.5% EGG-YOLK containing extender. Only progressive motility was significantly different (P<0.05) within extenders containing 2.5%, 5%, 7.5% and 10% EGG-YOLK. We conclude that Black Bengal buck semen can be cryopreserved effectively with tris-EGG YOLK-citrate-fructose-glycerol extender containing 2.5% EGG YOLK (V/V).

Background: Cryptosporidium parvum is a parasitic protozoan that functions as important causative agent of diarrhea in human and animals. The host's immune response to surface antigens of C. parvum has been previously demonstrated. In this respect, the role of humoral immunity in the development of host protective immunity against this protozoon has been well demonstrated. Methods: The effect of specific chicken EGG YOLK antibody (IgY) against recombinant C. parvum P23 was examined. IgY sample was prepared from EGGs of chickens immunized with recombinant C. parvum protein p23 and analyzed with C. parvum lysate and recombinant P23. Results: The anti P23 specific IgY was recognized a protein band with approximately 23 kDa in lysates prepared from the C. parvum oocysts. Also dot blot analysis of recombinant P23 showed that it could be recognized by the anti P23 specific IgY up to 1/1000 dilution of antibody. But the best antibody dilution for immunological studies was determined as 1:200.Conclusion: Since P23 is an immunodominant surface glycoprotein expressed in the early phase of infection, specific IgY against recombinant p23 could be recommended as a favorable candidate for passive immunization against C. parvum infection in human and animals.