62 research outputs found
Halotolerant streptomycetes isolated from soil at Taif region, Kingdom of Saudi Arabia II: RAPD-PCR analysis and salt tolerance-gene isolation
The genus Streptomyces is represented in nature by the largest number of species and varieties among the family Streptomycetaceae. This study aimed at extracting the DNA of four halotolerant Streptomyces strains followed by determination of DNA fingerprinting of them using a molecular tool. A trail to isolate salt tolerance gene(s) from their DNA was also aimed. RAPD-PCR technique was applied using seven RAPD-PCR primers. Results show that a total 71 fragments (65 polymorphic and six monomorphic) were amplified from the DNA of the four identified Streptomyces strains. The fragments were divided into polymorphic and monomorphic fragments. Three primers named OPA11, OPB15 and OPC07 did not show any monomorphic fragments. A number of 43 (7, 7, 8, 2, 9, 6 and 4) representing 60.56% were considered as unique DNA markers, and were amplified using OPA11, OPB15, OPC07, OPC18, OPD04, OPE05 and OPO14, respectively. Data shows similarity matrix between the four identified Streptomycs strains based on RAPD-PCR analysis ranged from 21.8 to 40.0. Results show that the P5CR gene was detected in the DNA extracts of three species, namely, Streptomyces cirratus-02; Streptomyces rishiriensis-04; Streptomyces luteogriseus-08, while, mtlD gene was only found in the DNA extracts of S. cirratus-02.Keywords: Streptomyces, halotolerant, salt tolerance genes, RAPD-PCR, Taif, KSAAfrican Journal of Biotechnology Vol. 12(13), pp. 1452-145
Halotolerant streptomycetes isolated from soil at Taif region, Kingdom of Saudi Arabia (KSA) I: Purification, salt tolerance range, biological and molecular identification
This study focuses on isolation and purification of some halotolerant streptomycetes from soil and sea water of western region, KSA as a source of salt tolerance gene(s). A few numbers (32) of streptomycetes-like colonies (SLC) were isolated and purified from two regions. From Jeddah, a number of 22 out of the 32 SLC were obtained, distributed between the sea water 12 (54.55%) and sea sediment soil 6 (27.27%).From Taif-soil, only 10 SLC were isolated. Results show that 31 SLC were grown on 3.5% salt, while, in the presence of 7.0% salt, 2, 3, 18, and 4 showed abundant (+++), moderate (++), weak (+), and in doubt (±) growth, respectively. Only five SLC were not able to grow at 7% salt. At the level of 10.5% salt, the number of SLC was decreased up to 4 (2 (+++), 1 (++) and 1(+)). In either 14% or 21% salt, four isolates were varied in their ability in growth as moderate or weak growth was recorded. These isolates were considered as halotolerant as they were able to grow in either the presence or normal growth medium. The four isolates which tolerate 14% salt (isolates 4 and 6) and 21% salt (isolates 2 and 8) were completely identified. The streptomycete isolate 2 appeared to be related to Streptomyces cirratus. Comparing the cultural, morphological and physiological characteristics of Streptomyces isolate 4 and 6, they were very likely to be strains of S. rishiriensis and S. alboflavus, respectively. Streptomyces isolate 8 was identified as a strain of S. luteogriseus. The nucleotide sequences of 16S rRNA gene was partially determined using the DNA template of the Streptomyces isolate 8. Results show that a final sequence of about 1462 nts was obtained and compared with eight universal Streptomyces and bacterial strains. This isolate could be classified as a new species of gray Streptomyces, and it was suggested to be named a new halotolerant Streptomyces sp. TSA-KSA strain (GenBank AB731746).Keywords: Streptomyces, halotolerant, identification, 16S rRNA, Taif, Kingdom of Saudi Arabia (KSA)African Journal of Biotechnology Vol. 12(19), pp. 2565-257
Molecular studies on some soil-Streptomyces strains of western region, Kingdom of Saudi Arabia (KSA)
Random amplified polymorphic of DNA-polymerase chain reaction (RAPD-PCR) analysis of the DNA extracted from seven Streptomyces strains of western region, KSA was the aim of this study. Partial sequence of 16S rRNA gene of Streptomyces polychromogenes was also attempted. Results show that a total number of 240 amplified fragments were amplified using 10 RAPD-PCR primers (OPA11, OPB10, OPB15, OPC03, OPC07, OPC18, OPD05, OPE05, OPO14 and OPO17). A total number of 97, 73, 88, 79, 100, 108 and 82 fragments were amplified from the DNA extracts of S. polychromogenes, Streptomyces chattanoogensis, Streptomyces lucensis, Streptomyces antibioticus, Streptomyces violans, Streptomyces griseorubiginosus and Streptomyces violaceus, respectively. An obvious variation in the amplified fragments was recorded using the 10 RAPD-PCR primers (31, 27, 17, 19, 23, 29, 24, 26, 23 and 21 fragments for the primers, respectively). The highest similarity (66.7%) was found between S. lucensis and S. chattanoogensis; lowest similarity (35%) was recorded between the gray S. chattanoogensis and the red S. violaceus. The 16S rRNA gene was isolated via PCR from the DNA of S. polychromogenes (1) and sequenced. Fragments of 1003 and 837 nts were amplified using the forward and reverse primers, respectively. On matching, a final sequence of about 1452 nts (GenBank: JQ962978.1) was obtained and compared with five universal Streptomyces strains and four bacterial clones. The percent identities between the isolate of this study and the compared bacterial strains was lowest (79.1%) compared to HQ844464.1 and highest (98.3%) compared to EU520331.1. Based on the phenotypic and genotypic (16S rRNA gene) features, the strain could be classified as a new strain of S. polychromogenes.Keywords: Identification, Streptomyces, RAPD-PCR, 16S rRNA gene, KSAAfrican Journal of Biotechnology Vol. 12(19), pp. 2558-256
Streptomyces noboritoensis isolated from rhizosphere soil and its use in controlling banana-tissue culture contaminants
In this study, the role of Streptomyces noboritoensis (14) isolated from the rhizosphere of banana plant and having antagonistic activity against the bacterial- and fungal-tissue culture contaminants was determined in vitro. Results show that the filtrate was more effective against the fungal-tissue culture contaminants than the bacterial-tissue culture contaminants. This was indicated when jars were fungifree and bacteria-free after one month and 21 days from incubation, respectively. Results of in vitro application show that the filtrate of S. noboritoensis (14) as a bio-control agent could be used for controlling the contaminants in banana. Data showed that treatment F (sterilized shoots treated with Streptomyces filtrate and cultivated on Streptomyces-inoculated medium) was the most effective followed by treatment E (sterilized shoots untreated with Streptomyces filtrate and cultivated on Streptomyces-inoculated medium). Therefore, the study suggests conducting further studies towards the use of streptomycetes in the biological control in a large scale production.Keywords: Streptomyces, tissue culture contaminants, antagonistic activities, bio-controlAfrican Journal of Biotechnology Vol. 12(20), pp. 2908-291
Taxonomy of Streptomyces strains isolated from rhizospheres of various plant species grown in Taif region, KSA, having antagonistic activities against some microbial tissue culture contaminants
This work was designed to identify and taxonomically classify Streptomyces strains isolated from the rhizospheres of various plant species; banana, rose, pomegranate and grape plants, having antagonistic activity against some microbial (bacteria and fungi) tissue culture contaminants. Streptomyces strains with the most potent antagonistic traits were identified using sequencing of 16S rRNA gene amplicons generated by PCR of DNA and blasting the sequences into GenBank. The Streptomyces isolates had antagonism against five identified fungi (Aspergillus fumigates, Aspergillus flavus, Aspergillus nidulans (1), Aspergillus nidulans (2), Cladosporium herbarum) and against five out of the 11 Gram positive bacilli bacterial contaminants. The three selected Streptomyces isolates (14, 15 and 17) were identified as strains of Streptomyces noboritoensis, Streptomyces albolongus and Streptomyces griseorubiginosus, respectively. Isolate 14 for which 1443 nucleotides were obtained was compared with eight universal Streptomyces strains and was classified as a new species of gray Streptomyces, to be named Streptomyces noboritoensis SSMA2-KSA strain. This study recommends conducting further studies on the use of streptomycetes in the biological control in a large scale production.Keywords: Taxonomy, Streptomyces, microbial tissue culture contaminants, antagonistic activities, 16S rRNAAfrican Journal of Biotechnology Vol. 12(14), pp. 1657-166
Virological and clinical characteristics of hepatitis delta virus in South Asia
<p>Abstract</p> <p>Background & Aims</p> <p>There is a paucity of data on the impact of hepatitis D virus (HDV) in patients with hepatitis B virus (HBV) infection from South Asia. We studied the impact of HDV co-infection on virological and clinical characteristics.</p> <p>Methods</p> <p>We collected data of 480 patients with HBsAg positive and a detectable HBV DNA PCR, who presented to the Aga Khan University, Karachi and Isra University in Hyderabad, Pakistan in the last 5 years. HDV co-infection was diagnosed on the basis of anti-HDV. ALT, HBeAg, HBeAb and HBV DNA PCR quantitative levels were checked in all patients. We divided all patients into two groups based on anti-HDV, and compared their biochemical, serological & virological labs and clinical spectrum. Clinical spectrum of disease included asymptomatic carrier (AC), chronic active hepatitis (CAH), immuno-tolerant phase (IP), and compensated cirrhosis (CC).</p> <p>Results</p> <p>HDV co-infection was found in 169 (35.2%). There were 164 (34.6%) HBeAg positive and 316 (65.4%) HBeAg negative patients. Mean ALT level was 66 ± 73 IU. 233 (48.5%) had raised ALT. HBV DNA level was ℠10e5 in 103(21.5%) patients. Overall, among HBV/HDV co-infection, 146/169 (86.4%) had suppressed HBV DNA PCR as compared to 231/311 (74.3%) patients with HBV mono-infection; p-value = 0.002. Among HBeAg negative patients 71/128(55.5%) had raised ALT levels among HBV/HDV co-infection as compared to 71/188 (37.8%) with HBV mono-infection (p-value = 0.002); levels of HBV DNA were equal in two groups; there were 27/128 (21%) patients with CC among HBV/HDV co-infection as compared to 23 (12%) in HBV mono-infection (p-value = 0.009); there were less AC (p-value = 0.009) and more CAH (p-value = 0.009) among HBV/HDV co-infection patients. Among HBeAg positive patients, serum ALT, HBV DNA levels and the spectrum of HBV were similar in the two groups.</p> <p>Conclusions</p> <p>HBV/HDV co-infection results in the suppression of HBV DNA. A fair proportion of HBV/HDV co-infected patients with HBeAg negative have active hepatitis B infection and cirrhosis as compared to those with mono-infection.</p
IL-17RA Signaling Amplifies Antibody-Induced Arthritis
Objective: To investigate the role of IL-17RA signaling in the effector phase of inflammatory arthritis using the K/BxN serumtransfer model. Methods: Wild-type and Il17ra 2/2 mice were injected with serum isolated from arthritic K/BxN mice and their clinical score was recorded daily. Mice were also harvested on days 12 and 21 and ankles were analyzed for cytokine and chemokine mRNA expression by qPCR on day 12 and for bone and cartilage erosions by histology on day 21, respectively. The induction of cytokine and chemokine expression levels by IL-17A in synovial-like fibroblasts was also analyzed using qPCR. Results: Il17ra 2/2 mice were partially protected from clinical signs of arthritis and had markedly fewer cartilage and bone erosions. The expression of several pro-inflammatory mediators, including the chemokines KC/CXCL1, MIP-2/CXCL2, LIX/ CXCL5 MIP-1c/CCL9, MCP-3/CCL7, MIP-3a/CCL20, the cytokines IL-1b, IL-6, RANKL and the matrix metalloproteinases MMP2, MMP3, and MMP13 were decreased in the ankles of Il17ra 2/2 mice compared to wild-type mice. Many of these proinflammatory genes attenuated in the ankles of Il17ra 2/2 mice were shown to be directly induced by IL-17A in synovial fibroblasts in vitro. Conclusions: IL-17RA signaling plays a role as an amplifier of the effector phase of inflammatory arthritis. This effect is likel
The Experience of Quality in Higher Education in the United Arab Emirates: In Times of Rapid Change and Complexities
In less than five decades, from offering formal education only in a few schools to a small tribal community to providing a selection of three public and approximately 100 private higher education institutions to the citizens of seven emirates creates a unique context in the United Arab Emirates (UAE). It is an evolution that corresponds with its remarkable economic growth. Quality assurance of diverse higher educational institutions requires complex schemes to ensure their fitness for purpose, while perhaps development and enhancement aspects need time to mature. The quality of the education is especially important because the UAE yearns for the diversified and knowledge-based economy; one that is led by its own citizens whose contribution to the workforce is currently less than 10%. This chapter highlights contextual complexities in the UAE that might have direct and/or indirect impacts on the quality experiences in the higher education sector, with proposed recommendations
FĂȘnomeno de Raynaud grave associado a terapia com interferon-beta para esclerose mĂșltipla: relato de caso
Clinical approach for the classification of congenital uterine malformations
A more objective, accurate and non-invasive estimation of uterine morphology is nowadays feasible based on the use of modern imaging techniques. The validity of the current classification systems in effective categorization of the female genital malformations has been already challenged. A new clinical approach for the classification of uterine anomalies is proposed. Deviation from normal uterine anatomy is the basic characteristic used in analogy to the American Fertility Society classification. The embryological origin of the anomalies is used as a secondary parameter. Uterine anomalies are classified into the following classes: 0, normal uterus; I, dysmorphic uterus; II, septate uterus (absorption defect); III, dysfused uterus (fusion defect); IV, unilateral formed uterus (formation defect); V, aplastic or dysplastic uterus (formation defect); VI, for still unclassified cases. A subdivision of these main classes to further anatomical varieties with clinical significance is also presented. The new proposal has been designed taking into account the experience gained from the use of the currently available classification systems and intending to be as simple as possible, clear enough and accurate as well as open for further development. This proposal could be used as a starting point for a working group of experts in the field
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