Volume 4, Issue 1

  • 2019, August

    original research

    Self-Adjuvanting Peptide Vaccines Against Cervical CancerOpen Access

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    Abstract [+]

    Background

    Cervical cancer is a common cause of cancer-related deaths in women worldwide, with a fatality rate second only to breast cancer. Human papillomaviruses (HPVs) are the main causative agents of cervical cancer, and are therefore obvious targets for vaccine development. Although two prophylactic HPV vaccines have been commercialized, therapeutic vaccines against HPVs have not been developed yet. Current vaccine technologies emphasize the power of small particles in targeting immune cells, and particles of 20-50 nm have been reported to induce optimal immune responses against a variety of pathogens and cancers.

    Methods

    We synthesized new nanoparticle-based vaccines against cervical cancer by using antigenic 8Qmin peptide epitope derived from HPV-16 E7 protein, a hydrophilic poly-(L-glutamic acid) (PGA) linker, and an 8-arm poly (tert-butyl acrylate) dendrimer-based delivery system (D8).

    Results

    Four different peptides containing 8Qmin and PGA of different lengths were successfully synthesized with high yield and purity. These were then conjugated to alkyne-functionalized D8 by copper-catalyzed alkyne-azide cycloaddition “click” reaction. The conjugates self-assembled into nanoparticles, with decreased particle size corresponding to a greater number of Glu units. The four vaccine candidates were tested in C57 black 6 (C57BL/6) mice bearing well-established (7-day-old) tumors to examine their therapeutic effects.

    Conclusion

    Interestingly, only one conjugate delayed tumor growth, and montanide adjuvanted antigen, used as a positive control, failed to demonstrate any therapeutic effect.

    Keywords

    Peptide-based subunit vaccine; Human papillomavirus; Polyglutamic acid; Therapeutic cancer vaccine; Polymer-peptide conjugate; Self-adjuvanting; Cervical cancer.


  • 2019, December

    original research

    Analysis of Antibiotic Resistance of the Probiotic Bacteria Found in Commercial Food ProductsOpen Access

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    Abstract [+]

    Aim

    The Lactobacillus is an industrially-important group of probiotic organisms that plays an important role in human health by inhibiting harmful and pathogenic bacterial growth, boosting immune function, and increasing resistance to infection. The aim of this study was to identify the probiotic bacteria Lactobacillus based on their phenotypic features and genotypic features. This study also shows the importance of probiotic bacterium, and the effects of their antibiotic resistance to human.

    Method

    Six different brands were cultured on man, rogosa and sharpe (MRS) agar. The identity of the culture was based on the characteristics of the strains of Lactobacillus spp. which was characterized using their phenotypic features (cell morphology, Gram’s staining tests which are specific for Lactobacillus genus). The bacterial deoxyribonucleic acid (DNA) was extracted by two different methods, boiled cell method and cetyl trimethylammonium bromide (CTAB) method. Furthermore, the extracted DNA yields were compared to determine which gives the best yield. The bacterial genus was detected with using genus specific primers, specific to the Lactobacillus. All the isolates were further subjected to antibiotic resistance test using disc diffusion method against a total of 4 antibiotics (Erythromycin, Tetracycline, Vancomycin and Ampicillin) and the antibiotic resistant genes of tet(M) & erm(B), were analyzed by polymerase chain reaction (PCR).

    Results

    Five isolates out of six samples (A to E) were found to exhibit multiple resistance against some of the most commonly used antibiotics. The isolates showed resistance toward tetracycline, erythromycin & vancomycin. Besides that, the isolates displayed a low-level of resistance toward ampicillin.

    Conclusion

    This study proves that antibiotic resistance is present in different species of probiotic strains, which may pose a food safety concern.

    Keywords

    Lactobacillus; Probiotics; Antibiotics; Tetracycline; Vancomycin; Erythromycin; Ampicillin; Antibiotic resistance.