Determination of contamination with Clostridium botulinum in two species of processed and non prosecced fish

Background and Objective: The Clostridium botulinum is one of the most important causative of food poisoning. Spores of Clostridium botulinum spread out in the soil, the sea sediments, the marine environments and the marine animals. In recent years use of the marine food products like as fish and cultured fish are elevated. The aim of this study was done to compare between processing and non processing fish infected by predominant type of Clostridium botulinum. Materials and Methods: This descriptive study was done on the 146 samples of fish in two species of processed and non prosecced that collected from Gilan province in Iran during 2008. These samples included the Liza auratus Fish (45 processed fish and 28 non processed fish) and the Salmo Trutta caspius Fish (34 processing fish and 39 non processing fish). The samples examined according to the APHA2000 and FDA2003 protocols. Data Analyzed with SPSS-13 and Chi-Square test. Results: 16 (11%) of samples (13% of the processed fish and 7.5% of non processed fish) were confirmed that infected by Clostridium botulinum. Also the dominant type of exotoxin was Type E. The Type E exotoxin was determined from 11 of the samples (6 processed fish and 5 non processed fish). Conclusion: This study showed that fish are infected by Clostridium botulinum special the type E. also use of fish in bad preparation (half cooking and add material in its stomach) may cause the food poisoning

Prevalency of imipenem-resistant bacterial strains isolated from hospital and accuracy of Iranian imipenem disc product

Background and Objective: Bacterial resistance to Imipenem is increased in bacterial infections in Iran. In regard to the importance of Imipenem in the treatment of nosocomial infections and the key role of disc diffusion method as a major antibiotic susceptibility testing assay, this study was done to determine the prevalency of imipenem-resistant bacterial strains isolated from hospital and accuracy of Iranian imipenem disc product. Methods: In this descriptive-analytic study, 241 bacteria were isolated from patients in different wards of the Baqyatallah hospital in Tehran, Iran during 2013-14. After streaking of the organisms, identification was performed by all conventional biochemical tests. The bacterial resistance to imipenem was determined by disk diffusion method using Iranian and Mast imipenem discs. True imipenem-resistant isolates were examined for susceptibility to six different antibiotic including Ciprofloxacin, Gentamicin, Cephalexin, Azitromysin, Tetracycline and Ceftazidim, using disk diffusion method. Results: The most prevalent isolates organisms were gram-negative bacilli (Klebsiella, Escherichia coli, and Pseudomonas aeruginosa, respectively). The common clinical source was urine and wound samples, respectively. Resistant to Imipenem was 68 (25.7 %) and 19 (7.8 %) based on the results of Iranian and Mast Imipenem discs, respectively. False results for Iranian Imipenem discs was higher than Mast Imipenem discs (P<0.05). Among the 19 true Imipenem resistant isolates, 17 micro organisms were Pseudomonas aeruginosa. 57% of isolated resistant to Imipenem were isolated from ICU ward. The most resistance was seen to Gentamicin (84%) and the lowest was seen to Ciprofloxacin (63%). 84% of isolated samples were multi drug resistance. Conclusion: Although a small percentage of the isolates obtained as important nosocomial pathogens were resistant to Imipenem, but the rate of multiple resistance and high rate of isolates obtained from ICU was noticeable

Evaluation of the Expression of Recombinant Type A Botulinum Neurotoxin Light Chain Loaded onto a Cell-Penetrating Peptide

BACKGROUND AND OBJECTIVE: Botulinum toxin type A (BoNT/A) is widely used in the treatment of some muscle contraction disorders through injection. This study aimed to produce recombinant protein through covalent bonding of the light chain of BoNT/A to the peptide TAT (47-57), and to create an optimized condition for expression and purification of the protein. METHODS: In this preliminary study, the nucleotide sequences of the light chain of BoNT/A and TAT peptide were obtained from Gen Bank, and genetic structures containing these sequences were designed and engineered. After cloning into the BL21 (DE3) E. coli vector, expression was induced by IPTG. Thereafter, optimum thermal condition and IPTG concentration for maximum expression were determined based on the difference in the intensity of staining between the bands on SDS-PAGE protein gel. The recombinant protein was purified through nickel column chromatography (Ni-NTA). FINDINGS: The produced chimeric protein is insoluble in normal conditions (1 mM IPTG and at 37˚ C). Through optimization of expression conditions (0.5 mM IPTG and at 18˚ C) 60% of the chimeric protein was produced as solution. CONCLUSION: Based on our results, through expressing the recombinant protein as a solution, the protein maintained its proper folding and function. Hence, the use of denaturation compounds for solution making and destabilization of folded protein structures is not required