Biotechnology and Genetic Engineering

Background: Practical challenges and translational issues have affected the widespread implementation of pharmacogenomics and personalized medicine. There are significant barriers to the translation of personalized medicine from research labs to practical application in a healthcare setting. Methods: The information in this review paper was collected via search engines and Pub-Med using the following search entries " pharmacogenomics " , " personalized medicine " , " translational issues ". Articles and papers published from 2010 onwards were included. Results: The gathered data presented in this paper illustrate the main challenges and trans-lational issues in the field of pharmacogenomics and personalized medicine. Conclusion: Costs in the drug discovery process and the implementation of personalized medical approaches are the main barriers to the translation of pharmacogenomics from laboratory to clinic. The lack of a unified system as well as the requirement for expert analysis of data is additional barriers.

In addition to its nutritional and therapeutic properties, camel milk has the ability to suppress the growth of a wide range of foodborne pathogens, but there is a lack of information regarding the behavior of these pathogens in products such as yogurt produced from camel milk. The objective of the current study was to investigate the behavior of Listeria monocytogenes and Escherichia coli O157:H7 during manufacture and storage of camel yogurt. Camel milk inoculated with L. monocytogenes and E. coli O157:H7 was fermented at 43°C for 5 h using freeze-dried lactic acid bacteria (LAB) starter cultures (Streptococcus thermophilus and Lactobacillus bulgaricus) and stored at 4 or 10°C for 14 d. Camel milk inoculated with L. monocytogenes and E. coli O157:H7 without starter culture was also prepared. During fermentation, the numbers of L. monocytogenes and E. coli O157:H7 increased 0.3 and 1.6 log cfu/mL, respectively, in the presence of LAB, and by 0.3 and 2.7 log cfu/mL in the absence of LAB. During storage at 4 or 10°C, L. monocytogenes increased 0.8 to 1.2 log cfu/mL by 14 d in camel milk without LAB, but in the presence of LAB, the numbers of L. monocytogenes were reduced by 1.2 to 1.7 log cfu/mL by 14 d. Further, E. coli O157:H7 numbers in camel milk were reduced by 3.4 to 3.5 log cfu/mL in the absence of LAB, but E. coli O157:H7 was not detected (6.3 log cfu/mL reduction) by 7 d in camel yogurt made with LAB and stored at either temperature. Although camel milk contains high concentrations of natural antimicrobials, L. monocytogenes was able to tolerate these compounds in camel yogurt stored at refrigerator temperatures. Therefore, appropriate care should be taken during production of yogurt from camel milk to minimize the potential for postprocess contamination by this and other foodborne pathogens.

The 104-kDa Listeria adhesion protein (LAP) in Listeria monocytogenes is involved in binding to various mammalian cell lines. However, the receptor that interacts with LAP in eukaryotic cells is unknown. In this study, scanning immunoelectron microscopy qualitatively demonstrated greater binding capacity of wild-type (WT) L. monocytogenes strain (F4244) than a LAP-deficient mutant strain (KB208) to Caco-2 cells. The goal of this study was identification of the host cell receptor for LAP. Using a Western blot ligand overlay assay, we identified a protein of 58 kDa to be the putative receptor for LAP from Caco-2 cells. N-terminal sequencing and subsequent database search identified this protein as heat shock protein 60 (Hsp60). Modified immunoseparation with protein A-Sepharose beads bound to the LAP-specific monoclonal antibody H7 (MAb-H7) and a sequential incubation with LAP preparation and Caco-2 lysate confirmed the receptor to be the same 58-kDa protein. Western blot analysis with anti-Hsp60 MAb of whole-cell adhesion between Caco-2 and WT also revealed the receptor protein to be a 58-kDa protein, thus corroborating the identification of Hsp60 as a host cell receptor for LAP. Furthermore, the anti-Hsp60 antibody also caused approximately 74% reduction in binding of L. monocytogenes WT to Caco-2 cells, whereas a control antibody, C11E9, had no effect on binding. The adhesion mechanism of L. monocytogenes to eukaryotic cells is a complex process, and identification of Hsp60 as a receptor for LAP adds to the list of previously discovered ligand-receptor modules that are essential to achieve successful adhesion.

The effect of non-reducing sugars (sucrose, lactose and trehalose), complex carbohydrates (cyclodextrin and dextran), infant formula or egg yolk on the stability of purified chicken IgY was evaluated under different conditions. Regardless of the protectant that was used, about 20% of the activity of IgY was lost during freeze-drying except in the presence of infant formula where the loss of IgY activity was approximately 75%. The lowest loss of activity (10%) was observed when no protectant was used. Trehalose was the best protectant followed by cyclodextrin and infant formula when IgY was stored for 6 or 14 weeks at different temperatures. Sucrose, lactose and dextran were not effective as protectants under these conditions. IgY activity was completely lost after pepsin treatment in the presence of sugars or complex carbohydrates while 34 and 40% of its activity was recovered when treated in the presence of infant formula and egg yolk, respectively. IgY was fairly stable after trypsin treatment with the recovery of residual activity being between 75-100% depending on the protectant. Finally, the effect of heat treatment on the stability of aqueous solutions of IgY was evaluated. IgY was stable at 50, 60 or 70°C while complete loss of IgY activity was observed at 80 and 90°C in the presence of all protectants except infant formula and egg yolk were about 5% residual activity was observed. These results demonstrate that the addition of different compounds to IgY during freeze-drying or storage at different temperatures or subjecting them to enzyme treatments provided varying and in most cases considerable protection against loss of biological activity.

Inhalation of olive pollen is a major cause of allergic respiratory diseases in Mediterranean region. Using bags attached to the branches, pollens were collected from 36 olive cultivars grown in Jordan just before bloom. Proteins were extracted from pollens and analysed by SDS-PAGE and immunoblotting using antisera collected from patients with history of olive pollen-allergy. Immunoblot results showed that 25

A conductometric immunosensor was developed for the detection of one of the most common foodborne pathogens, Escherichia coli O157:H7 (E. coli O157:H7), by conductometric sensing. The sensor was built based on a polyaniline/zinc oxide (PANI/ZnO) nanocomposite film spin-coated on a gold electrode. Then, it was modified with a monoclonal anti-E. coli O157:H7 antibody as a biorecognition element. The fabricated nanostructured sensor was able to quantify the pathogens under optimal detection conditions, within 30 min, and showed a good detection range from 101 to 104 CFU/mL for E. coli O157:H7 and a minimum detection limit of 4.8 CFU/mL in 0.1% peptone water. The sensor efficiency for detecting bacteria in food matrices was tested in ultra-heat-treated (UHT) skim milk. E. coli O157:H7 was detected at concentrations of 101 to 104 CFU/mL with a minimum detection limit of 13.9 CFU/mL. The novel sensor was simple, fast, highly sensitive with excellent specificity, and it had the potential f...