Molecular screening of gastric Helicobacter pullorum recovered from different avian species in Egypt.

Helicobacter pullorum (H. pullorum) is a bacterium that colonizes the intestines of poultry and causes gastroenteritis. Because these species are known as human and/or animal pathogens, identification of H. pullorum is becoming increasingly necessary. The bacterium has been linked to colitis and hepatitis in humans after being transmitted by infected meat consumption. Misdiagnosis of other enteric zoonotic pathogens such as Campylobacter and other Helicobacter species makes the diagnosis of H. pullorum extremely difficult. This study focused on the molecular detection of H. pullorum from the stomach (proventriculus and gizzard) of different avian species as new target organs for detection and transmission between avian species. Proventriculus and gizzards were obtained from 40 freshly dead chickens and resident wild birds (n=40). Diarrhea was found in the farms that were surveyed. DNA was extracted from all collected samples to conduct PCR amplification. The samples were screened for Helicobacter genus-specific 16s using C97 and C05 primers. To confirm the existence of H. pullorum, the positive samples were sequenced. H. pullorum was recorded in two out of 40 chicken samples. In addition, H. pullorum was recorded in one out of 40 resident wild birds. The 16S rRNA gene sequence for Helicobacter genus-specific in poultry and wild birds showed a 100% homology. In conclusion, broiler chickens and resident wild birds are possible reservoirs for H. pullorum, according to this report, and possibly act as a source of infection for humans via the food supply.

Cationic colloidal silica membrane perturbation as a means of examining changes at the sinusoidal surface during liver regeneration.

By employing the cationic colloidal silica membrane density perturbation technique, we examined growth factor receptor and extracellular matrix (ECM) changes at the sinusoidal surface during rat liver regeneration 72 hours after 70% partial hepatectomy (PHx). At this time after PHx, hepatocyte division has mostly subsided, while sinusoidal endothelial cell (SEC) proliferation is initiating, resulting in avascular hepatocyte islands. Because of the discontinuous nature of the surface of liver SEC, ECM proteins underlying the SEC, as well as SEC luminal membrane proteins, are available to absorption to the charged silica beads when the liver is perfused with the colloid. Subsequent liver homogenization and density centrifugation yield two separate fractions, enriched in SECs as well as hepatocyte basolateral membrane-specific proteins up to 50-fold over whole liver lysates. This technique facilitates examination of changes in protein composition that influence or occur as a result of SEC mitogenesis and migration during regeneration of the liver. When ECM and receptor proteins from SEC-enriched fractions were examined by Western immunoblotting, urokinase plasminogen activator receptor, fibronectin, and plasmin increased at the SEC surface 72 hours after PHx. Epidermal growth factor receptor, plasminogen, SPARC (secreted protein, acidic and rich in cysteine, also called osteonectin or BM40), and collagen IV decreased, and fibrinogen subunits and c-Met expression remained constant 72 hours after PHx when compared to control liver. These results display the usefulness of the cationic colloidal silica membrane isolation protocol. They also show considerable modulation of surface components that may regulate angiogenic processes at the end stage of liver regeneration during the reformation of sinusoids.

Production of gentamicins by Micromonospora purpurea.

The natural medium contained the following ingredients (g/l): glucose 8.0, or black strap molasses (treated with 0.2--0.3 g/l EDTA) 12.0, fodder yeast (50.0% total nitrogen) 2.0, or folder yeast (40.0% total nitrogen) 6.0, or yeast extract 8.0, or tryptone 8.0, and CaCO3 1.0. Treated black strap molasses with EDTA and fodder yeast proved to be effective in the fermentative production of gentamicins. The most suitable chelating agent was EDTA in the form of disodium for the treatment of Komombo molasses in a concentration of 0.2--0.3 g/l, while potassium ferrocyanide and methylene blue had depressing effects on the production of gentamicins. The most effective carbon source, present in Egyptian black strap molasses, was glucose. Addition of glucose to the medium was preferable at the beginning of the fermentation process. Trace elements present in molasses were very essential for the microbial growth and biosynthesis of gentamicins as proved when molasses ash was added to the natural medium. Organic nitrogen sources were more suitable than inorganic nitrogen sources for the production of gentamicins by Micromonospora purpurea. The microorganism utilized the synthetic medium, but the antibiotic yields were less than those produced in the natural medium. The synthetic medium exhibited stimulatory effects of certain amino acids, organic acids, vitamins, and purine and pyrimidine bases on the fermentative production of gentamicins. Therefore, the ingredients increasing yields of gentamicins were mainly phenylalanine, iso-leucine, lysine, methionine, leucine, arginine, glycine, beta-alanine, cystine, tryptophan, malic acid, maleic acid, cobalamin, folic acid, riboflavin, vitamin B1, vitamin B6, biotin, nicotinamide, uracil, adenine, guanine, and adenosine. Trace elements (Co, Mo, Fe, Cu, Zn, and Mn) exhibited their important role on the biosynthesis and production of gentamicins by Micromonospora purpurea.

Mode of action of gentamicin antibiotics produced by Micromonospora purpurea.

Gentamicin antibiotics were produced fermentatively by Micromonospora purpurea. They were separated into gentamicin C1, C1a and C2 by paper chromatographic technique, using chloroform, methanol, and 17.0% of NH4OH (2: 1: 1 v/v) as developing solvent. The different antibiotics showed variable antimicrobial activities. The gentamicin antibiotics inhibited the biosynthesis of DNA and RNA of the proteins, present in the cells of Staphylococcus aureus.