Showing 5 results for Shigella
Seyed Mojtaba Moosavian, Amir Siahpoosh, Effat Abbasi, Heidar Darabifar,
Volume 13, Issue 1 (4-2010)
Abstract
Background: Albizzia lebbeck is used for the treatment of diarrhea and dysentery. In this study the efficacy of hydro-ethanolic extract of this plant on enteric gram-negative and aerobic gram-positive bacillis was determined. Materials and Methods: In this experimental-clinical trial, cold maceration method by ethanol was used for extraction of Albizzia lebbeck fruit, seed, flower and leaves. Then its polyphenolic components were separated by ethyl acetate. After concentrating the different extracts through disk diffusion and tube dilution, the effect of minimal inhibitory concentration (MIC) and minimal bacteriocidal concentration (MBC) of their antibacterial component on shigella dysenteriae, proteus mirabilis, escherchia coli, bacillus cereus and bacillus anthracis were evaluated. Also, the antibacterial effects of Albizzia lebbeck extracts together and in combination with some antibiotics, were compared through variance analysis. Results: Different extracts of Albizzia lebbeck just had similar and positive effects on shigella dysenteriae, bacillus cereus, and bacillus anthracis. However, the hydro-ethanolic fruit extract was more effective than the falavnoid fruit, flower and leave extracts. MIC and MBC results for antibacterial material on the three aforementioned bacterias were 0.125 and 0.25 gram/ml, respectively while the effects of the polyphenolic components of this plant's fruit were similar to its hydro-ethanolic extracts. Conclusion: Through the identification of different components of Albizzia lebbeck and the attainment of new formulations of these components, the grounds will be provided for its application on treatment of patients with inflammatory diseases and asthma, and on improvement of their immune system.
Sayed Mostafa Hosseini, Mojtaba Saadati, Mohammad Bagher Yakhchali, Bahar Nayeri Fasaei , Hoora Ahmadydanesh, Morteza Mirzaei, Kamal Baghery, Mokhtar Zare,
Volume 15, Issue 2 (6-2012)
Abstract
Background: Live attenuated Shigella vaccines have shown promise in inducing protective immune responses in human clinical trials. The aim of this study was to design and construct pDS132::∆icsA as a suicide plasmid for targeted deletion of a region of icsA gene in Shigella. Materials and Methods: In this experimental study, species and serotypes of Shigella isolated from diarrhea samples of children at Firozabadi and Milad Hospitals of Tehran were confirmed by using serological and PCR tests. Identification primers of icsA gene were designed and then cloned to the pGEM-5zf vector and sequenced. According to icsA restriction enzyme map, 1751 bp of icsA gene was deleted by HincП restriction enzyme and the ∆icsA was constructed successfully. The pGEM∆icsA vector was digested by use of SphI and SalI enzymes and was then cloned to a suicide vector (pSD132). Precision of the process was confirmed by phenotype and genotype tests. Results: The Shigella dysenteriae type 1 strain was verified by serological tests and PCR. Sequence of the icsA gene in the native strain was identical to the strains submitted in the gene-bank database. Since the pDS132::∆icsA contains 1484 bp derived from icsA gene, it can be used to disrupt icsA gene as a specific suicide vector. Conclusion: Application of suicide systems facilitated mutant construction in more specific and effective methods in comparison with the other primary techniques such as serial passage.
Hosein Honari, Iman Amlashi, Mohammad Ebrahim Minaee, Sadegh Safaee,
Volume 16, Issue 4 (7-2013)
Abstract
Background: Shigellosis is a major global issue of human health. To date, no effective vaccine has been found against Shigella. One of the major virulent factors in Shigella dysenteriae type 1 is Shigella enterotoxin or STx. STxB has immunogenic, adjuvant, or carrier properties. Vaccine candidate antigens can be coupled with this adjuvant for production of an appropriate vaccine. IpaD has a key role in invasion, virulence, and infection by Shigella.
Materials and Methods: In this study, the gene sequences of STXB and ipaD were obtained from gene bank and corresponding genes were prepared as synthetic construct and then transferred to E. coli BL21DE3. By PCR amplification and enzymatic digestion, protein expression levels were assessed. Its protein expression was confirmed by Western blot technique. After extraction by affinity chromatography, the recombinant protein was injected four times to guinea pigs. The pigs were, then, challenged by Shigella felexneri 2a and active toxin of E. coli O157:H7.
Results: The results showed that groups of guinea pigs challenged with 28×LD50 of toxin completely survived. Furthermore, guinea pigs were challenged by inducing Shigella felexneri 2a in their eyes. The results showed that the control pigs got cataracts, whereas the immune pigs were in health.
Conclusion: The findings of this study suggest that this recombinant protein is a good candidate for production of a recombinant vaccine against Shigella family.
Mohammad Reza Hashemzadeh, Mojtaba Saadati, Mohamadreza Baghaban Eslaminejad, Reza Aflatoonian, Mokhtar Zarea,
Volume 18, Issue 3 (6-2015)
Abstract
Background: Shigella is the causative agent of human shigellosis and its lipopolysaccharide is detected by TLR4. TLR4 belongs to Toll-like receptors family and many immunological pathways are triggered when these receptors are stimulated. Many researches showed increasing in TLR4 expression in mesenchymal stem cells through lipopolysaccharide treatment. The main goal of this study is detecting the optimum lipopolysaccharide between shigella strains through stimulation of immune system for vaccine studies.
Materials and Methods: In this experimental study human bone marrow derived mesenchymal stem cells were treated with three distinct concentrations (0.1, 0.01, and 0.001) of shigella (S. flexneri, S. dysenteriae, S. sonnei) extract containing lipopolysaccharide. Then TLR4 expression in mRNA level was investigated by RT-PCR and Q-PCR. The cells treated with phosphate buffered saline have been considered as a control group.
Results: Expression of TLR4 was shown in all of case groups except treatment with concentration 0.001 of extracts from sonnei and dysenteriae and also control group. The variations in the expression of TLR4 was dose-dependent in all of case groups. The maximum expression of TLR4 related to treatment with extract from shigella flexneri strain and the minimum expression related to treatment with shigella sonnei extract. The use of lipopolysaccharide from E. coli as a positive control indicated that lipopolysaccharide in shigella extracts is responsible for the increased expression of TLR4.
Conclusion: The TLR4 expression level was increasesed by S. flexneri extract, so it could be recommended for increasing vaccine efficiency.
Elnaz Abbasi, Javad Javaheri, Hamid Momeni, Ehsanollah Ghaznavi-Rad,
Volume 22, Issue 2 (6-2019)
Abstract
Background and Aim: Shigella species are one of the main causes of dysentery. This study aimed to determine the frequency and antibiotic resistance patterns of Shigella species isolated from infectious diarrhea samples in khomein, Iran.
Materials and Methods: A total of 54 infectious diarrhea samples obtained from patients were included in this descriptive cross-sectional study from June 2017 through November 2018. The infectious diarrhea samples were cultured to XLD, MacConkey agar and GN Broth. The phenotypic antibiotic resistance profiles were determined.
Ethical Considerations: This study with research ethics code IR.ARAKMU.REC.1396.307 has been approved by research ethics committee at Arak University of Medical Sciences.
Findings: Out of 54 infectious diarrhea samples, 11 (20.3%) with Shigella spp were identified using culture media. S. sonnei 9(81.8%) and S. flexneri 2(18.1%) were the single species found. The highest antibiotic resistance rates were found for cotrimoxazole 11(100%), ampicillin 10(90.9%), cefixime, cefotaxime and ceftriaxone 9(81.8%). In this study, 8 (72.7%) of the isolates were ESBL and 1 (9%) were AmpC positive.
Conclusion: This study showed that Shigell spp are the main bacterial agent causing dysentery in infectious diarrhea samples in khomein, Iran. This should be taken into consideration by infectious specialists especially during empirical treatment.
