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result(s) for
"RAPD"
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Increase of blaOXA-23-like in Acinetobacter baumannii at a tertiary care center in Lebanon between 2007 and 2013
2018
Introduction: The multi-drug resistant nature of Acinetobacter baumannii isolates have rendered many broad-spectrum antimicrobial agents ineffective against them. The purpose of this retrospective study is to define and compare the molecular characteristics of A. baumannii isolates from patients at a tertiary care center in Lebanon from two outbreaks, the first in 2007-2008, as part of a case-controlled study involving A. baumannii cases admitted to the ICU, and the second in 2013. Methodology: A total of 148 A. baumannii clinical isolates were collected from various clinical specimens during 2007-2008 and 2013. All A. baumannii isolates were screened for blaOXA-23-like and blaOXA-51-like genes of carbapenem resistance. Additionally, in an effort to assess the degree of the isolates’ genomic relatedness, random amplification of polymorphic DNA (RAPD) was performed. Results: There was an increase in the prevalence of blaOXA-23-like and blaOXA-51-like genes between the two time periods; however, only 22% isolate genomic relatedness was calculated between 2007-2008 and 2013. Taking 80% as a margin of compatibility, 31 distinct clusters containing 2 to 11 strains were observed when both time periods were analyzed. Conclusion: The presence of numerous clusters accompanied by a predominant increase in the prevalence of blaOXA-23-like between 2007 and 2013 suggests a horizontal transmission of the gene within various strains of the species, contributing to the persistent increase in carbapenem resistance over the years. Therefore, infection control measures are required with compliance among all healthcare workers.
Journal Article
Advances in Chemical and Biological Methods to Identify Microorganisms—From Past to Present
by
Alexandrino de Souza, Veruska Cintia
,
S. Kaushik, Karishma
,
Rodrigues, Célia F.
in
Biochemical tests
,
chromogenic media
,
Classification
2019
Fast detection and identification of microorganisms is a challenging and significant feature from industry to medicine. Standard approaches are known to be very time-consuming and labor-intensive (e.g., culture media and biochemical tests). Conversely, screening techniques demand a quick and low-cost grouping of bacterial/fungal isolates and current analysis call for broad reports of microorganisms, involving the application of molecular techniques (e.g., 16S ribosomal RNA gene sequencing based on polymerase chain reaction). The goal of this review is to present the past and the present methods of detection and identification of microorganisms, and to discuss their advantages and their limitations.
Journal Article
Genetic Similarity and Gene Flow in Freshwater Snail, Bulinus Globosus Populations from Selected Natural Habitats in Kano State (Nigeria)
2023
The population genetic structure of
, an important intermediate host snail for
, in Nigeria was studied using Random Amplified Polymorphic DNA Technique. The five primers amplified genomic DNA of
from three populations with one region and 999 permutations. With 79 loci, the % polymorphic bands for each primer across all population samples were 55.70% (River Karaye), 58.23% (River Bagwai) and 60.76% (River Kano). The mean heterozygosity was 0.175, 0.190 and 0.197 for snails caught in Karaye, Bagwai, and Kano respectively. The highest genetic distance (0.141) and identity (0.919) were observed between the populations of Bagwai, Kano, and Karaye and Bagwai. The variations within and among the snail populations were 76% and 4% respectively, while the UPGMA dendogram revealed no outliers. The gene pool of
was microgeographically fragmented.
Journal Article
Combining Ability Analysis and Marker-Based Prediction of Heterosis in Yield Reveal Prominent Heterotic Combinations from Diallel Population of Rice
by
Mohammad Sharif Raihan
,
Md. Mobinur Rahman
,
Shinya Oba
in
additive gene effects
,
Agricultural production
,
Agriculture
2022
Combining ability along with heterosis was elucidated in the 21 F1 hybrid population of rice derived from a 7 × 7 diallel mating design. Furthermore, to formulate a strategy for marker-based prediction of heterosis, the molecular genetic diversity (GD) was then surveyed among the seven parental lines with RAPD markers. Analysis of combining ability revealed significant GCA and SCA variances and the ratio between the aforesaid genetic parameter was more than unity for most of the traits signifying the preponderance of additive gene action. Hybrid combination Double Rice × Pokkali was the best specific combiner for the traits pollen fertility percentage (%), panicle length (cm), filled grains/panicle (no.) and grain yield/hill (g) while Muktagacha × BRRI dhan29 and Basmati × Double Rice were the best specific combiners for grain length (mm) and 1000-grain weight (g), respectively. Regarding the magnitude of heterosis, Double Rice × Pokkali exhibited maximum heterobeltiosis for panicle length (33.33%) and the number of filled grains/panicle (144.01%). Furthermore, Pokkali × Chinigura was verified for producing the highest heterobeltiosis for tillers/hill (173.17%), as well as grain yield/hill (71.05%). The heatmap relying on molecular genetic diversity exposed the highest genetic distance between Chinigura and Pokkali followed by Muktagacha and Pokkali. Unweighted neighbor-joining trees clustered the parental lines into three groups indicating the presence of considerable genetic diversity among those seven parental genotypes. A positive and significant correlation was explored between molecular GD with specific combining ability as well as heterosis for all of the traits revealing the huge potentiality of hybrid performance prediction using RAPD markers with the present set of individuals. Thus, exploration of definite genomic regions underlying the candidate genes for respective traits relying on such RAPD-generated data following an advanced molecular marker approach would pave the path of mining out yielder heterotic combinations.
Journal Article
Trends in plant research using molecular markers
by
Manzano-Agugliaro, Francisco
,
Mesa-Valle, Concepción
,
Garrido-Cardenas, Jose Antonio
in
Agriculture
,
Agronomy
,
Amplified fragment length polymorphism
2018
The evolution of the improvement in the feld of agronomy is fundamental for its adaptation to the new exigencies that the current world context raises. In addition, within these improvements, this article focuses on those related to the biotechnology sector. More specifcally, the use of DNA markers that allow the researcher to know the set of genes associated with a particular quantitative trait or QTL. The use of molecular markers is widely extended, including: restriction fragment length polymorphism, random-amplifed polymorphic DNA, amplifed fragment length polymorphism, microsatellites, and singlenucleotide polymorphisms. In addition to classical methodology, new approaches based on the next generation sequencing are proving to be fundamental. In this article, a historical review of the molecular markers traditionally used in plants, since its birth and how the new molecular tools facilitate the work of plant breeders is carried out. The evolution of the most studied cultures from the point of view of molecular markers is also reviewed and other parameters whose prior knowledge can facilitate the approach of researchers to this feld of research are analyzed. The bibliometric analysis of molecular markers in plants shows that top fve countries in this research are: US, China, India, France, and Germany, and from 2013, this research is led by China. On the other hand, the basic research using Arabidopsis is deeper in France and Germany, while other countries focused its eforts in their main crops as the US for wheat or maize, while China and India for wheat and rice.
Journal Article
Effect of Ancymidol and Phloroglucinol on the Number and the Quality of Shoots in the Micropropagation of Date Palm (Phoenix dactylifera L.)
2024
The disadvantages of practical date palm micropropagation are tissue browning, low callus proliferation rate, low multiplication efficiency, and vitrification. The aim of the study was to determine the effect of ancymidol (Ancy) and phloroglucinol (PG) on the growth and some biochemical components of the ‘Barhee’ date palm cultured
. The combination of 0.75 mg·l
Ancy and 50 mg·l
PG was found to be the most effective in terms of callus regeneration rate (89%) and number of shoots (14.3). A reduction in browning was observed in tissues cultured on media supplemented with 0.75 mg·l
Ancy in combination with 25 or 50 mg·l
PG. The medium supplemented with 0.75 mg·l
Ancy and 50 mg·l
PG eliminated shoot vitrification. Effective micropropagation was associated with increased carbohydrate and protein content. In this study, the genetic stability of plants obtained by micropropagation was confirmed by DNA-based RAPD fingerprinting. The results may indicate that the micropropagation protocol used in this study was suitable and applicable to the production of genetically stable date palm plants on a mass scale.
Journal Article
regulatory effect of melatonin on physiological, biochemical and molecular parameters in cold-stressed wheat seedlings
by
Erdal, Serkan
,
Genisel, Mucip
,
Demir, Yavuz
in
Agriculture
,
antioxidant activity
,
Antioxidants
2014
We investigated the possible mediatory role of melatonin in protecting wheat plants from cold stress. Ten-day-old wheat seedlings were pretreated with 1 mmol l⁻¹ melatonin for 12 h and subsequently exposed to stress conditions at 5/2 °C (day/night) for 3 days. Cold stress caused serious reductions in leaf surface area, water content, and photosynthetic pigment content, whereas melatonin application attenuated these reductions. Accumulation of reactive oxygen species (ROS), including superoxide and hydrogen peroxide, was very high in cold-stressed plants and caused lipid peroxidation in membranes. Concomitantly, ROS damaged the DNA profile and negatively influenced expression and/or activity of many enzymes, including RuBisCo. When compared to controls, cold-stressed plants had higher activities of the antioxidant enzymes superoxide dismutase, guaicol peroxidase, ascorbate peroxidase, and glutathione reductase and higher levels of the antioxidant compounds total ascorbate, reduced ascorbate, total glutathione, reduced glutathione, and phenolic substances; however, this elevation could not cope with the destructive effects of cold stress. Melatonin-pretreated plants exhibited greater increases in these parameters comparison with untreated cold-stressed plants. Isozyme bands monitored in native gel and RuBisCo expression supported these changes. Also, due to the cold-induced increase in dehydroascorbate and oxidized glutathione, the corrupted redox status in the cell was ameliorated by melatonin application. Similarly, levels of the osmoprotectants total soluble protein, carbohydrate, and proline were also increased by cold stress; however, melatonin-applied seedlings had a higher content of these solutes in comparison to untreated cold-stressed plants. We suggest that melatonin can improve plant resistance to cold stress in wheat seedlings by directly scavenging ROS and by modulating redox balance and other defence mechanisms.
Journal Article
Antibiogram, Prevalence of OXA Carbapenemase Encoding Genes, and RAPD-Genotyping of Multidrug-Resistant Acinetobacter baumannii Incriminated in Hidden Community-Acquired Infections
by
Metwally, Lobna
,
Hetta, Helal F.
,
El-Taher, Ayat
in
Acinetobacter baumannii
,
antibiogram
,
carbapenemase encoding genes
2020
Acinetobacter spp. has gained fame from their ability to resist difficult conditions and their constant development of antimicrobial resistance. This study aimed to investigate the prevalence, susceptibility testing, OXA carbapenemase-encoding genes, and RAPD-genotyping of multidrug resistant Acinetobacter baumannii incriminated in hidden community-acquired infections in Egypt. The antimicrobial susceptibility testing was assessed phenotypically using Kirby–Bauer disk diffusion method. Also, Modified-Hodge test (MHT) was carried out to detect the carbapenemases production. Multiplex-PCR was used to detect the carbapenemase-encoding genes. Furthermore, the genetic relationship among the isolated strains was investigated using RAPD fingerprinting. The bacteriological examination revealed that, out of 200 Gram-negative non-fermentative isolates, 44 (22%) were identified phenotypically and biochemically as Acinetobacter spp. and 23 (11.5%) were molecularly confirmed as A.baumannii. The retrieved A.baumannii strains were isolated from urine (69%), sputum (22%), and cerebrospinal fluid (csf) (9%). The isolated A. baumannii strains exhibited multidrug resistance and the production rates of carbapenemases were 56.5, 60.9, and 78.3% with meropenem, imipenem, and ertapenem disks, respectively. The blaOXA-24-like genes were the most predominant among the tested strains (65.2%), followed by blaOXA-23 (30.4%) and blaOXA-58 (17.4%), in addition, the examined strains are harbored IMP, VIM, and NDM genes with prevalence of 60.9, 43.5, and 13%, respectively, while KPC and GES genes were not detected. RAPD-PCR revealed that the examined strains are clustered into 11 different genotypes at ≥90% similarity. Briefly, to the best of our knowledge, this study is the first report concerning community-associated A. baumannii infections in Egypt. The high prevalence of hidden multidrug-resistant (MDR) and extensively drug-resistant (XDR) A.baumannii strains associated with non-hospitalized patients raises an alarm for healthcare authorities to set strict standards to control the spread of such pathogens with high rates of morbidity and mortality.
Journal Article