Showing 14 results for Colonization
Volume 3, Issue 2 (5-2017)
Abstract
Background: Accessory colonization factor is located immediately adjacent to and downstream of TCP cluster. These genes (acfA, B, C, D) are involved in bacterial colonization and pathogenesis. The aim of this study was to analyze the ACF cluster prevalence rate and gene content in clinical isolates of Vibrio cholerae.
Materials and Methods: All of the 21 V. cholerae isolates used in this study were collected during 2011-2012 outbreaks in Iran. All of the isolates were screened by biochemical tests and confirmed by specific PCR for 16srRNA-23srRNA intergenic space. The gene content of ACF cluster in the isolates was analyzed using 4 primer pairs with overlapping sequences and then subjected into Restriction Fragment Length Polymorphism (RFLP) assay.
Results: Among the 21 V. cholerae isolates, all of them (100%) were identified as V. cholerae O1 Inaba, 20 (95%) isolates were determined with El Tor biotype specificity, and 1 isolate (5%) appeared as Classical biotype. A total of 18 strains (85.8 %) contained a complete set of ACF-associated genes, 3 strains (14.2 %) were negative for ACF cluster, and all of the strains showed similar RFLP pattern to each other and to V. cholerae ATCC 14035.
Conclusion: The results showed that O1 Inaba was the dominant serotype and positive for ACF cluster in pathogenic V. cholerae isolates collected during 2011-2012 in Iran. The presence of some ACF negative strains with potentially pathogenic characteristics proposed that other colonization factors might have been involved in causing pathogenicity and diarrhea in these strains.
Volume 5, Issue 3 (12-2017)
Abstract
Abstract
The appearance of comparative literature in Algeria has been influenced by different risings and fallings after entering French men to Algeria in 1830, this country involved in the colonizing movements, at first, they tried to change people’s language and culture, hence most of comparative studies have been influenced by this condition, therefore, they were written in French. Finally, it was in 1962 that this country entered the political spring after people’s revolution, therefore, Arabic language entered comparative studies by re-examining Algeria in European works such as French and Germany people, there were found some universities in comparative literature and other literary branches and international conferences, in order to develop the comparative men in Algeria in developing comparative literature analysis in the survey of comparative literature in Algeria by classification of contemporary history into colonization and post-colonization. literature in Algeria by classification of contemporary history into colonization and post-colonization.
Keywords: Algeria, Comparative Literature, Colonization, Political Spring, French and Arabic Language.
Volume 12, Issue 2 (9-2023)
Abstract
Rhizoctonia root rot caused by Rhizoctonia solani is one of the critical factors influencing bean plants' yield. This study investigates the effects of some biofertilizers for controlling R. solani and their impact on the growth parameters of bean plants in the greenhouse. Biofertilizers, Funneliformis mosseae (F. mos), vermicompost (Verm), and mealworm frass (Meal), were used in a completely randomized design with five replications. Compared with diseased control, biofertilizers applied separately or in combination, reduced disease severity (except Meal) and disease incidence (except Verm). The combination of Meal + Verm had the best effect on both indices. All biofertilizer treatments increased the dry root weight (except Verm and F. mos + Meal + Verm), fresh root, and foliage weight. Also, root length, and dry foliage weight was increased only in combination treatments, and stem length in Meal + Verm and F. mos + Verm. The highest growth of foliage parameters, root length, and fresh and dry root weight was observed in Meal + Verm, F. mos + Verm, and F.mos + Meal, respectively. The highest mycorrhizal colonization was in F. mos and F. mos + Verm. Therefore, combinations of biofertilizers had better effects on the plant growth and inhibition of Rhizoctonia root rot. The tested biofertilizers and their combinations could be considered as promising tools for reducing the use of chemicals and enhancing sustainable agriculture and disease management. The appropriate timing and application rates for these biofertilizers must be determined accurately during field experiments.
Volume 13, Issue 4 (1-2011)
Abstract
Objective: Enterotoxigenic Escherichia coli is considered as the most important agent of children diarrhea and mortality in developing countries. This bacterium causes 300-600 thousands of deaths in the children under 5 years of age per year. With difficulties in treatment as well as its wide prevalence, designing an effective vaccine against this microorganism is the objective of world Health Organization (WHO). The CfaB protein as immunogen and major subunit of fimberia has a critical role in the bacterial attachment to small intestine epithelium and the produced antibody against this protein can prevent attachment of bacterium to epithelial surface. Hence, this molecule alone or with other virulent factors has been considered by many researchers in vaccine designing. In this study, expression of colonization factor B with the aim of studying the immunogenesity of this protein as a component of vaccine candidate was performed.
Materials and Methods: cfaB gene was amplified by PCR and cloned into pET28a and its expression was evaluated. Since there was no expression, which was due to presence of rare codon, the cfaB gene was again cloned into pET28a using codon bias in E.coli and subsequently expressed.
Results: Presence of a 20KD band on SDS-PAGE gel indicated the expression of CfaB protein, which was later confirmed by immunoblotting with anti-His tag and anti CfaB antibodies and purified on Ni-NTA column.
Conclusion: Codon optimization and expression in heterologous hosts is a useful approach for obtaining large quantities of recombinant protein.
Amir Roshan, Seyyed Ali Reza Hosseini Beheshti,
Volume 14, Issue 3 (5-2007)
Abstract
The problem of "alienation" and the "alienated man" is one of the most attractive features of the critique of modernity. Ali Shariati, the contemporary Iranian theorist who was highly concerned with the critique of both tradition and modernity, introduced the idea of a "third way". As the main cause for decadence, defining and defying alienation was at the core of Shariati's intellectual agenda. In this paper, we will explain his view on alienation and his recommended solution which invites peoples of the third world to return to their very identity. Then, some critical arguments raised by his critics will be explored and assessed.
Volume 14, Issue 4 (7-2012)
Abstract
The impact of land use intensity on the abundance and diversity of arbuscular mycorrhizal fungi (AMF) was investigated at six land use types viz., natural forest, grassland, acacia plantations, cardamom plantations, coffee plantations and paddy fields in the Niligiri Biosphere of the Western Ghats in South India. There was no significant difference in AMF root colonization in different land use types during pre-monsoon but there was a significant difference in AMF root infection ratings between different land use types during post-monsoon season, where it was higher in natural forests and grasslands. The AMF spore density and infective propagules were significantly higher in grasslands and acacia plantations compared to all other land use types during both seasons. Except for paddy fields, the spore density and number of infective propagules were higher in post-monsoon season compared to pre-monsoon season in other land use types. The numbers of AMF species identified were 56 during pre-monsoon and 67 species during post-monsoon season suggesting seasonal variations in diversity. During both seasons Glomus fasciculatum was recorded in maximum number of sampling points across the landscape followed by G. geosporum during pre-monsoon and G. mosseae during post-monsoon season. The species diversity was highest in natural forests and grasslands as compared to other land use types in both seasons. The species richness index for AMF was highest in natural forests and least in paddy fields during both study periods. The sand content, bulk density, total N, organic C, alkaline and acid phosphatases positively correlated with AMF activity while clay, silt, K, total P and available P were negatively correlated.
Volume 15, Issue 4 (2-2013)
Abstract
Objective: This study presents a simple method for isolation, expansion and purification of neonatal mouse spermatogonial stem cells. Methods: We used enzymatic digestion to isolate a cell suspension of spermatogonia and Sertoli cells from neonatal 2-day-old mice. The cells were cultured in DMEM/F12 that contained 10% serum for two weeks. Sertoli and spermatogonia cell characteristics were confirmed by examining for the presence of vimentin and PLZF proteins, respectively. To assess the rate of spermatogonia stem cell expansion, the area and number of colonies were measured during the two weeks of culture. At the end of the second week, we detected spermatogonia cell-specific expressions of the Stra8, Piwill2, DAZL, and Mvh genes. Results: Current results indicated that isolated Sertoli and spermatogonia cells were immunopositive for specific markers. During the culture period, a significant difference was seen in the number and area of spermatogonial stem cell colonies (PConclusion: Our study showed that co-culture of spermatogonia and Sertoli cells from same source provides a convenient and efficient environment. This co-culture, without the addition of external growth factors and chemical manipulations, can be used for proliferation of spermatogonia stem cells.
Volume 15, Issue 7 (12-2013)
Abstract
A greenhouse experiment was conducted to investigate the effects of mycorrhial fungus (Glomus mosseae) on cadmium (Cd) toxicity in pepper (Capsicum annuum L. cv. Zhongjiao 105) plants. Half of plants were inoculated with arbuscular mycorrhizal fungi (AMF). Cd was supplied in the form of cadmium chloride at 0.0, 0.1 and 0.5 mM through irrigation water in the soil. Mycorrhizal colonization was higher in the control than in cadmium-treated soil. Dry weights of root and shoot of mycorrhizal (M) plants were higher than non mycorrhizal (NM) ones in both control and cadmium treatments. Measurements of Cd concentration indicated that M plants immobilized more Cd in the root and partitioned less Cd to the shoots. Cd decreased the leaf chlorophyll content, total sugar and total protein contents, and the concentrations of phosphorous and magnesium. M plants had greater contents of chlorophyll, total sugar, total protein and P and Mg concentrations than NM plants. Moreover, increasing the Cd concentration caused an increase in malondialdehyde (MDA) content in leaves of pepper plants; however, M plants showed a lower MDA content than NM plants. Cd decreased the activity of superoxide dismutase (SOD) in leaves of NM and M plants, on the other hand, it increased the activity of peroxidase (POD) and ascorbate peroxidase (APX) in leaves of NM and M plants. APX was stimulated more than POD in M plants versus NM plants, suggesting that APX is a major player in H2O2-scavenging in M plants. The study suggests that mycorrhization with G. mosseae can be a suitable way to induce Cd-stress resistance in pepper plants.
Volume 16, Issue 2 (9-2013)
Abstract
Objective: This study presents an efficient, cost-effective method to improve proliferation and colonization of spermatogonial stem cells (SSCs) in vitro. Methods: Isolated SSCs from neonate mice were cultured in DMEM culture medium with 10% fetal bovine serum (FBS). In the first phase of the study, the temperature was controlled by low intensity pulsed ultrasound stimulation (LIPUS) of the plate that contained the culture medium. In the next phase, SSCs were stimulated by LIPUS with 200 mW/cm2 with 20% and 40% duty cycle for five days. Proliferation and colonization of SSCs were on the seventh day. Results: LIPUS treatment of mouse SSCs increased the proliferation rate and colonization of SSCs in the experimental groups compared to the control group. Average proliferation rate in the 20% duty cycle group was 1.46±0.06, in the 40% duty cycle group it was 2.00±0.1 and for the control group, it was 1.26±0.06. The average number of colonies in the 20% duty cycle group was 24±7.7, whereas the 40% duty cycle group had 62±1.4 colonies and the control group had an average of 19±5.5 colonies. Average colony diameters were as follows: 186.6±2.07 µm (20% duty cycle group), 185.3±4.4 µm (40% duty cycle group) and 190.0±2.0 µm (control group). Our results showed a significant increase in proliferation rate and number of colonies in the experimental groups compared to the control group (P<0.05), whereas no significant differences were observed between groups in colony diameters. Conclusion: These results suggested that LIPUS treatment can be an efficient, cost-effective method to improve proliferation and colonization of SSCs during in vitro culture.
Volume 20, Issue 3 (10-2017)
Abstract
Objective: The TcpA colonization factor of pili A and the cholera toxin are the most important pathogenesis factors of Vibrio cholera that have the ability to stimulate the immune system. The aim of this study is a bioinformatics analysis of the expression of CtxB-TcpA recombinant chimeric protein in E. coli, and production of antibody against it in mice.
Methods: We designed a gene cassette that contained the CtxB and TcpA genes, and a spacer linker by using bioinformatics. Characteristics that include the structure of the chimer protein and epitopes were studied. In order to build a gene cassette, TcpA and CtxB genes were proliferated and cloned in pET28a(+). CtxB-TcpA gene expression was induced by IPTG. The produced CtxB-TcpA recombinant protein was confirmed by SDS-PAGE and Western blot analyses. Antibody produced from mice serum was isolated and confirmed by ELISA.
Results: The codon adaptation index of the optimized gene was 0.9. The prevalence ratio codons increased to 74% through codon optimization. Enzyme analysis verified the chimeric gene CtxB-TcpA cloning in the pET28a (+) expression vector. A protein with a molecular weight of 35 kDa was seen on SDS-PAGE. Its reaction with anti-histidine antibodies was confirmed by Western blot. The purified protein was 33.100 mg/l. Immunization of mice induced a serum antibody response.
Conclusion: The chimeric protein can be considered a good candidate for effective immunity against cholera.
Volume 21, Issue 1 (1-2019)
Abstract
Cultivars of Cucumis melo L. are important economic crops planted in both saline and non-saline soils in Iran. Root rot on C. melo caused by Phytophthora melonis is one of the most devastating soil-borne diseases causing great loss. C. melo crops cultivated in saline soil adjacent to Maharloo Lake (salt lake) in Fars Province have been associated with diseases caused by Phytophthora species for many years. In this study, effect of salinity on Phytophthora root rot on C. melo under hydroponic system was investigated: Four-week-old plants of three cultivars, namely, Shahde-Shiraz, Dastanbo-Khorasan, and Kharbozeh-Mashhad grown in Nukaya solution were subjected to salinity stress for one week. A week later, all plants were inoculated with zoospore suspension of P. melonios. After 48 hours, inoculated solution was replaced by fresh nutrient solution and post-inoculation salt-stressed treatment was applied to some plants. Based on shoot dry weight and concentration of Na+, K+, and Cl-, cultivars Shahde-Shiraz and Dastanbo-Khorasan were sensitive and resistant to salinity and also with the highest and lowest colonization of roots by P. melonis, respectively. Interaction of salinity and infection by P. melonis reduced shoot dry weight in the salt-tolerant cultivar more than salt-sensitive plants. Salinity increased root colonization by P. melonis compared to non-saline condition. The increase in root colonization due to salinity was not significantly different in Shahde-Shiraz and Kharbozeh-Mashhad cultivars. In Dastanbo-Khorasan, due to its higher resistance to P. melonis, salinity resulted in significant increase in root colonization, indicating reduction of root resistance due to salinity stress.
Mehrdad Ramzan-Nia,
Volume 21, Issue 4 (10-2014)
Abstract
The importance or centrality of Persian histories (whether imperial, regional or universal) can be gauged from the deep reliance placed by British historians on them for their own understanding of India’s past. The examples are numerous: Dow, Erskine, Elliot and Dowson explored Persian sources for their writings. Stewart also based his History of Bengal mainly on Persian materials; Mill did not know Persian and so wrote his History of India from Persian sources translated into English. Marshman used published English translations of Persian texts in the compilation of his History of Bengal. Hunter also depended for his understanding of the insight into the history of Muslim rule in Bengal on Persian source materials translated for him into English. Elphinstone, Thomas, Wheeler, Keene, Blochmann and Berveridge were all good Persian scholars and used, in addition to Persian sources, coins, inscriptions and archaeological finding for their writings can be fitted with this group. The recent work of Kumkum Chatterjee alerts us to the twin activities of British scholars and historians: translating Persian histories, as well as writing new histories of India based on the already established Persian model. The former indicates a serious engagement of colonial scholars with older models of history writing (as the appreciation heaped on the A’in as a historical source in the preface to its published edition indicates); the latter proves the adage that imitation was indeed, in this context, a form of flattery, however unintended.
Volume 24, Issue 4 (7-2022)
Abstract
Biofilm formation and rhizosphere colonization of the plants are the main infrastructures for the biological control of the plant diseases. Bacteria accumulation in the protective layer, which results from their self-production of Exopolysaccharides (EPS), is called the biofilm. The formation of these complex structures originates from the multicellular behaviors of bacteria. Various elements can play a role in these mechanisms. In this study, we examined biofilm formation, root colonization, and salt tolerance to four concentrations of NaCl in the strains of Bacillus velezensis (Q12, US1, and UR1). The results showed that the biofilm strength plays an important role in the efficiency of tomato root colonization. Furthermore, UR1 that had defects in producing the surfactin, iturin, and fengycin using Ultrahigh-Performance Liquid Chromatography-High Resolution Electrospray Ionization Mass Spectrometry (UHPLC-HRESIMS), was incapable of tolerance to salinity, biofilm formation, competition, and rhizosphere colonization. Confocal Laser Scanning Microscopy (CLSM) studies showed that strains US1 and Q12 differed in the biofilm strength, the position of the bacteria that are located laterally, polar, or both, and root colonization. Q12 was introduced as the best strain in all these experiments. Also, based on the findings of this and previous studies, the possibility to create the subpopulations influenced by genetic diversity in Bacillus velezensis strains during biofilm formation is suggested.
Iran Maria Maleki, Iran Behzad Pourgharib,
Volume 30, Issue 4 (10-2023)
Abstract
In Postcolonialism the issue of the influential power of dominant hegemony over the resultants of cultural confrontation between colonized and colonizer is preponderantly under scrutiny. Frantz Fanon is an influential figure in building upon this conceptual framework; whose oeuvre is bestrewed with postulations regarding the consequences of colonization and racism on the identity, experience, and the psyche of colored people. By utilizing Fanon’s thought, this paper intends to analyze different aspects of the black experience, such as alienation, inferiority, and assimilation in Edward P. Jones’s Pulitzer-winning novel, The Known World (2003). Throughout the novel, the conduct of free or bonded black characters within the institution of slavery reflects that of the white culture, and Fanon’s ideas are called upon to investigate the origin and possible consequence and implications of such behaviors.