Isolation of Thermoalkalophilic-?-amylase Producing Bacteria and Optimization of Potato Waste Water Medium for Enhancement of ?-amylase Production

Sixty one thermoalkalophilic bacteria were isolated from soil samples in Saudi Arabia’s southern region. Isolate TA-38, obtained from the Tanomah region, showed the best performance for enzyme production and was submitted for further study. It was identified as Bacillus axarquiensis based on 16S rRNA gene sequencing studies. The feasibility of using potato waste water as a simple and cheap medium for the production of ?-amylase was evaluated compared with starch broth medium. The production of ?-amylase in the potato waste water medium was only 13.8% less than that of the starch medium. Maximum enzyme production was achieved after 48 hours of cultivation at the beginning of the stationary phase at pH 10.0 and 50 0C. The appropriate addition of starch; nitrogen; phosphate; and calcium to potato waste water significantly enhanced the production of ?-amylase. The enzyme production reached a maximum of 64.5 Uml-1 with the potato wastewater adding with 0.5 % starch; 0.4 % yeast extract; 0.04% CaCl2-2H2O and 0.05 % KH2PO4.  The optimization of the potato waste water medium led to an approximately 4.02 fold increase in the production of ?-amylase compared to starch broth medium. Data indicated that the potato waste water contained substrates which could be used by bacterial isolate for the production of ?-amylase production and the developed procedure was cost effective since it requires only a slightly addition of nutrients to the medium. Keywords: Isolation; ?-amylase; 16S rRNA; Production; Potato waste water; Thermoalkaliphilic bacteria

Extreme genetic fragility of the HIV-1 capsid

Genetic robustness, or fragility, is defined as the ability, or lack thereof, of a biological entity to maintain function in the face of mutations. Viruses that replicate via RNA intermediates exhibit high mutation rates, and robustness should be particularly advantageous to them. The capsid (CA) domain of the HIV-1 Gag protein is under strong pressure to conserve functional roles in viral assembly, maturation, uncoating, and nuclear import. However, CA is also under strong immunological pressure to diversify. Therefore, it would be particularly advantageous for CA to evolve genetic robustness. To measure the genetic robustness of HIV-1 CA, we generated a library of single amino acid substitution mutants, encompassing almost half the residues in CA. Strikingly, we found HIV-1 CA to be the most genetically fragile protein that has been analyzed using such an approach, with 70% of mutations yielding replication-defective viruses. Although CA participates in several steps in HIV-1 replication, analysis of conditionally (temperature sensitive) and constitutively non-viable mutants revealed that the biological basis for its genetic fragility was primarily the need to coordinate the accurate and efficient assembly of mature virions. All mutations that exist in naturally occurring HIV-1 subtype B populations at a frequency >3%, and were also present in the mutant library, had fitness levels that were >40% of WT. However, a substantial fraction of mutations with high fitness did not occur in natural populations, suggesting another form of selection pressure limiting variation in vivo. Additionally, known protective CTL epitopes occurred preferentially in domains of the HIV-1 CA that were even more genetically fragile than HIV-1 CA as a whole. The extreme genetic fragility of HIV-1 CA may be one reason why cell-mediated immune responses to Gag correlate with better prognosis in HIV-1 infection, and suggests that CA is a good target for therapy and vaccination strategies

Allergen Immunotherapy in Children User’s Guide

Allergen immunotherapy is a cornerstone in the treatment of allergic children. The clinical efficiency relies on a well-defined immunologic mechanism promoting regulatory T cells and downplaying the immune response induced by allergens. Clinical indications have been well documented for respiratory allergy in the presence of rhinitis and/or allergic asthma, to pollens and dust mites. Patients who have had an anaphylactic reaction to hymenoptera venom are also good candidates for allergen immunotherapy. Administration of allergen is currently mostly either by subcutaneous injections or by sublingual administration. Both methods have been extensively studied and have pros and cons. Specifically in children, the choice of the method of administration according to the patient's profile is important. Although allergen immunotherapy is widely used, there is a need for improvement. More particularly, biomarkers for prediction of the success of the treatments are needed. The strength and efficiency of the immune response may also be boosted by the use of better adjuvants. Finally, novel formulations might be more efficient and might improve the patient's adherence to the treatment. This user's guide reviews current knowledge and aims to provide clinical guidance to healthcare professionals taking care of children undergoing allergen immunotherapy

How safe are the biologicals in treating asthma and rhinitis?

A number of biological agents are available or being investigated for the treatment of asthma and rhinitis. The safety profiles of these biologic agents, which may modify allergic and immunological diseases, are still being elucidated. Subcutaneous allergen immunotherapy, the oldest biologic agent in current use, has the highest of frequency of the most serious and life-threatening reaction, anaphylaxis. It is also one of the only disease modifying interventions for allergic rhinitis and asthma. Efforts to seek safer and more effective allergen immunotherapy treatment have led to investigations of alternate routes of delivery and modified immunotherapy formulations. Sublingual immunotherapy appears to be associated with a lower, but not zero, risk of anaphylaxis. No fatalities have been reported to date with sublingual immunotherapy. Immunotherapy with modified formulations containing Th1 adjuvants, DNA sequences containing a CpG motif (CpG) and 3-deacylated monophospholipid A, appears to provide the benefits of subcutaneous immunotherapy with a single course of 4 to 6 preseasonal injections. There were no serious treatment-related adverse events or anaphylaxis in the clinical trials of these two immunotherapy adjuvants. Omalizumab, a monoclonal antibody against IgE, has been associated with a small risk of anaphylaxis, affecting 0.09% to 0.2% of patients. It may also be associated with a higher risk of geohelminth infection in patients at high risk for parasitic infections but it does not appear to affect the response to treatment or severity of the infection

Sublingual immunotherapy in children with allergic rhinoconjunctivitis mono-sensitized to house-dust-mites: a double-blind-placebo-controlled randomised trial.

Background Although sublingual immunotherapy (SLIT) has been demonstrated to be a safe and efficient treatment in children with seasonal allergic rhinitis (AR), there is little evidence on the efficacy of SLIT with house-dust-mite (HDM) extract in children with isolated perennial AR. Objectives We sought to assess the clinical efficacy and safety of HDM-SLIT in children with isolated allergic rhinitis-conjunctivitis mono-sensitized to HDM without asthma symptoms. Methods Twenty-two children (aged 5-10 years) with perennial AR and conjunctivitis symptoms mono-sensitized to Dermatophagoides pteronyssinus and Dermatophagoides farinae were enrolled. During a 2 months run-in period, symptom and medication scores, lung functions, bronchial hyperreactivity, nasal provocation and skin prick tests were evaluated. Subjects were randomized to active or placebo using a double-blind method. A total of eighteen subjects were randomised to receive either active SLIT or placebo for 12 months. Daily symptom and medication scores, baseline lung functions, bronchial hyperreactivity, nasal provocation and skin prick tests were recorded and re-evaluated at the end of treatment. Results After one year of treatment, no significant differences were detected in the between groups and within group comparisons based on total rhinitis symptom/medication scores (p > 0.05). Skin reactivity to Dermatophagoides pteronyssinus was significantly reduced in HDM-SLIT compared to placebo group (p = 0.018). A significant reduction in nasal sensitivity was observed in SLIT group after one year treatment when compared to baseline (p = 0.04). Total conjunctivitis symptoms were reduced significantly in both active and lacebo group at the end of treatment compared to baseline. The proportion of patients with non-specific bronchial hyperreactivity increased to almost 3-fold in placebo group compared to baseline. Conclusion HDM-SLIT was not superior to placebo in reducing isolated rhinoconjunctivitis symptoms within 12 months of treatment. However, HDM-SLIT has a modulating effect on allergen-specific nasal and skin reactivity in isolated perennial AR children. Clinical Trial Registration The trial was registered at Anzctr.org.au number, ACTRN12613000315718. © 2013 Elsevier Ltd. All rights reserved