Journal of Applied Biotechnology Reports
Volume:2 Issue: 1, Winter 2015

Lateral flow assay، a simple and rapid test to detect various agents; have found many applications in different fields. One of the most important issues in the construction of a Lateral Flow assay is the increasing of its sensitivity and efficiency by processing of analytical layer. This study، aimed to investigate the performance of، Nellulose، Nitrocellulose، Nylon and PVD as different analyticallayer in morphine Lateral flow strip as a model. Cyanogens bromide، acetonitrile، methanol and specific polymers were used to activate cellulose، nitrocellulose، PVDF and nylon respectively. BSA-morphine and anti morphine polyclonal antibodies were immobilized orderly in test and control bands different concentrations of morphine were prepared as sample solution. Results showed that activated supports have better detection level in comparison with control strips. Among activated supports nitrocellulose showed more reliable results rather than others and introduced as a suitable support for construction of analytical layer and antibody immobilization. Nylon and PVDF supports due to its hydrophobic nature and cellulose due to high capillary property and non-uniform texture showed inappropriate results. Using proper supports for design of lateral flow strips can improve the sensitivity and detection level of this system.

Staphylococcus aureus is a hazard to human health since they can cause a wide variety of hospital-associated infections ranging from minor skin infections to post-operative wound infections and food poisoning which produces many different virulence factors, including enterotoxins (SEs). Although studies have been done regarding the difference between virulence factors of sensitive strains and resistant to antibiotics, the aim of this study was to investigate this topic in different patients. This cross-sectional study was performed on 100 patients admitted to a hospital in Tehran. After preparing of wounds samples, antibiogram study was done by disc diffusion method and prevalence of staphylococcal enterotoxin type B or seb gene was confirmed by Polymerase Chain Reaction. Data was analyzed using SPSS 17 software. Results showed that the highest percentage of isolates with positive seb gene is about 7% which related to amoxicillin (6.6%), penicilline and cotrimoxazole (6.5%). More than 90% of isolate are resistant to amoxicillin, penicillin and cotrimoxazol. According to results, a significant relationship between seb gene and resistance to related antibiotics was not observed.

Magnetite (Fe3O4 and NiO) nanoparticles with a size range of 40–60 nm were prepared by sol-gel technique in nano and micro reverse micelles (water- in-oil). The surface properties, size, morphology and crystallographic structure of Fe3O4 and NiO particles are characterized by means of X-ray diffraction, transmission electron microscope and scanning electron microscope which will give much valuable information about these materials. In addition, synthesis of nanoparticles can be easily implemented because it is simple and environmentally friendly.

Enterococcus and lactococcus are Gram-positive cocci that often occur in pairs (diplococci) or short chains, and are difficult to differentiate from streptococci on physical characteristics alone. Enterococcus faecium because have concern antibiotic resistant, consider difficult as probiotic. The results of an assay show that a probiotic E. faecium strain might be a potential recipient of Vancomycin resistance genes. For analysis of this concept, 13 samples of traditional cheeses were collected from different areas in Khorramabad city and identified with using phenotypic methods, and then the bacteriocin was extract from indentified bacteria. Agar diffusion method was used to assay the antimicrobial activities of bacteriocin produced by isolated bacteria against Pseudomonas aeruginosa, Proteus vulgaris, Staphylococcus aureus, E. coli, Bacillus cereus and Bacillus subtilis. On the other hand, antibiotic resistance of these bacteria was test using antibiogram method. The results showed that some of bacteria such as P. aeruginosa, S. aureus, and E. coli are intermediately resistance while P. vulgaris was completely sensitive and B. cereus and B. subtilis were resistant. Also, the Enterococcus faecium was resistant to kanamycin and trimethoprim antibiotics and intermediatly to clindamycin and tetracycline, and sensitive to amoxicillin and erythromycin. Lactococcus lactis was sensitive to trimethoprin, amoxicillin, tetracycline, and erythromycin while was resistant to kanamycin and clindamycin. In this study both bacteria enterococcus faecium and lactococcus lactis had an inhibitory effect on pathogenic bacteria and, these bacteria also have an appropriate antibiotic resistance to most antibiotics.