The role of horizontal transfer in the evolution of a highly variable lipopolysaccharide biosynthesis locus in xanthomonads that infect rice, citrus and crucifers

<p>Abstract</p> <p>Background</p> <p>Lipopolysaccharide (LPS) is a pathogen associated molecular pattern (PAMP) of animal and plant pathogenic bacteria. Variation at the interstrain level is common in LPS biosynthetic gene clusters of animal pathogenic bacteria. This variation has been proposed to play a role in evading the host immune system. Even though LPS is a modulator of plant defense responses, reports of interstrain variation in LPS gene clusters of plant pathogenic bacteria are rare.</p> <p>Results</p> <p>In this study we report the complete sequence of a variant 19.9 kb LPS locus present in the BXO8 strain of <it>Xanthomonas oryzae </it>pv. <it>oryzae </it>(Xoo), the bacterial blight pathogen of rice. This region is completely different in size, number and organization of genes from the LPS locus present in most other strains of Xoo from India and Asia. Surprisingly, except for one ORF, all the other ORFs at the BXO8 LPS locus are orthologous to the genes present at this locus in a sequenced strain of <it>X. axonopodis </it>pv. <it>citri </it>(Xac; a pathogen of citrus plants). One end of the BXO8 LPS gene cluster, comprised of ten genes, is also present in the related rice pathogen, <it>X. oryzae </it>pv. <it>oryzicola </it>(Xoc). In Xoc, the remainder of the LPS gene cluster, consisting of seven genes, is novel and unrelated to LPS gene clusters of any of the sequenced xanthomonads. We also report substantial interstrain variation suggestive of very recent horizontal gene transfer (HGT) at the LPS biosynthetic locus of <it>Xanthomonas campestris </it>pv.<it> campestris </it>(Xcc), the black rot pathogen of crucifers.</p> <p>Conclusion</p> <p>Our analyses indicate that HGT has altered the LPS locus during the evolution of <it>Xanthomonas oryzae </it>pathovars and suggest that the ancestor of all <it>Xanthomonas oryzae </it>pathovars had an Xac type of LPS gene cluster. Our finding of interstrain variation in two major xanthomonad pathogens infecting different hosts suggests that the LPS locus in plant pathogenic bacteria, as in animal pathogens, is under intense diversifying selection.</p

Clinicoradiological correlation in birth asphyxia

Background: Hypoxic Ischemic Encephalopathy (HIE) is the most dreaded neurological disease of the new-born. Assessment of severity of HIE would help proper parent counseling and early institution of stimulation therapy for better development of the infant.Methods: This study was conducted between December 2012 and May 2014. 37 term neonates with perinatal asphyxia were the subjects. The cranial ultrasound, EEG and MRI findings of these babies are analysed and correlated with each other and with clinical staging and the neurological condition of the babies at discharge.Results: Among the 37 neonates, 21 were of HIE stage 2 and 16 were of stage 3. Sensitivity of EEG in detecting abnormality in the neurological condition according to our study is 76.9%, specificity 87.5%, positive predictive value 76.9%, negative predictive value 87.5%. Sensitivity of severe pattern of injury in MRI brain in detecting abnormality in neurological condition according to our study is 76.9%, specificity 91.6%, positive predictive value 83.3%, negative predictive value 88%. Involvement of both basal ganglia and cortex in MRI brain had statistically significant correlation with abnormal neurological condition at discharge in our study (P = 0.04).Conclusion: An abnormal EEG and MRI brain in a term new-born with Hypoxic Ischemic Encephalopathy (HIE) is associated with poor neurological outcome. Involvement of basal ganglia/thalamus and cortex together in the MRI are predictors of abnormal outcome.

Variation suggestive of horizontal gene transfer at a lipopolysaccharide (lps) biosynthetic locus in Xanthomonas oryzae pv. oryzae, the bacterial leaf blight pathogen of rice

BACKGROUND: In animal pathogenic bacteria, horizontal gene transfer events (HGT) have been frequently observed in genomic regions that encode functions involved in biosynthesis of the outer membrane located lipopolysaccharide (LPS). As a result, different strains of the same pathogen can have substantially different lps biosynthetic gene clusters. Since LPS is highly antigenic, the variation at lps loci is attributed to be of advantage in evading the host immune system. Although LPS has been suggested as a potentiator of plant defense responses, interstrain variation at lps biosynthetic gene clusters has not been reported for any plant pathogenic bacterium. RESULTS: We report here the complete sequence of a 12.2 kb virulence locus of Xanthomonas oryzae pv. oryzae (Xoo) encoding six genes whose products are homologous to functions involved in LPS biosynthesis and transport. All six open reading frames (ORFs) have atypical G+C content and altered codon usage, which are the hallmarks of genomic islands that are acquired by horizontal gene transfer. The lps locus is flanked by highly conserved genes, metB and etfA, respectively encoding cystathionine gamma lyase and electron transport flavoprotein. Interestingly, two different sets of lps genes are present at this locus in the plant pathogens, Xanthomonas campestris pv. campestris (Xcc) and Xanthomonas axonopodis pv. citri (Xac). The genomic island is present in a number of Xoo strains from India and other Asian countries but is not present in two strains, one from India (BXO8) and another from Nepal (Nepal624) as well as the closely related rice pathogen, Xanthomonas oryzae pv. oryzicola (Xoor). TAIL-PCR analysis indicates that sequences related to Xac are present at the lps locus in both BXO8 and Nepal624. The Xoor strain has a hybrid lps gene cluster, with sequences at the metB and etfA ends, being most closely related to sequences from Xac and the tomato pathogen, Pseudomonas syringae pv. tomato respectively. CONCLUSION: This is the first report of hypervariation at an lps locus between different strains of a plant pathogenic bacterium. Our results indicate that multiple HGT events have occurred at this locus in the xanthomonad group of plant pathogens

Quantitative Digital Subtraction Radiography (DSR) as an approach for evaluating crestal alveolar bone density changes around teeth following orthodontic tooth movement.

Aim: The aim of the present study was to retrospectively evaluate changes in bone density using DSR&nbsp; at the crestal and subcrestal regions of interproximal bone around posterior teeth (premolars and molars) before and after&nbsp; orthodontic treatment using digital OPGs. Materials &amp; Method : A total of 14 Pre and Post operative digital image pairs were obtained from the department of Orthodontics and 28 regions were sampled and analyzed. The selected patients were in the age group of 13-18 years. The mean duration of orthodontic treatment was 1.5 years. All pre and post operative radiographs were assessed at baseline and after completion of orthodontic treatment using DSR. All subtracted images were subsequently imported into The Image Tool&reg; software to calculate the average density of Gray levels&nbsp; in the areas that showed changes in subtraction. Results: Out of 28 test regions 23 regions (82.14%) showed an increase in bone density whereas 5 regions (17.85%) showed a decrease in bone density. The mean bone density of the&nbsp; ROIs was 151.18 (gray level = 151.18 &plusmn; 19.97 SD). A one sample t test for statistical significance was carried out. The difference of the Mean values was found to be 23.18. The obtained p value was &lt;0.001 at 95% confidence interval (15.44 to 30.92) Conclusion: In the present study, we have found that 23 out of 28 regions&nbsp; (82.14%) showed significant increase in bone density whereas 5 regions (17.85%) showed a decrease in bone density. DSR is a valuable tool to assess subtle radiographic changes that occur in the alveolar bone during and after orthodontic therapy and can be used to monitor the bony changes over treatment period

Review Paper on NEO News Recommender Junction

Neo News Recommender Junction refers to the branch of data mining that deals with the techniques devoted to the decrease of human endeavors and association in accomplishing assignments. The primary target of Neo News Recommender Junction (NNRJ) is to prescribe news to a user based on user’s past history access through building application and website. Online news reading has turned out to be exceptionally prominent as the web gives access to news articles from a huge number of sources the world over. A key test of news sites is to help clients discover the articles that are intriguing to peruse. In this paper, we display our research on creating customized news proposal framework. For user’s who are signed in and have unequivocally empowered web history, the recommendation framework constructs profiles of users interests based on their past search behavior. To see how users news interest change after some time, we combine the information filtering mechanism using learned user profiles with an existing collaborative filtering mechanism to generate personalized news recommendations. Investigates the live activity of News site exhibited that the joined strategy enhances the nature of news proposal and expands the movement to the site

Statistical experiment analysis of wear and mechanical behaviour of abaca/sisal fiber-based hybrid composites under liquid nitrogen environment

Ice accretion on various onshore and offshore infrastructures imparts hazardous effects sometimes beyond repair, which may be life-threatening. Therefore, it has become necessary to look for ways to detect and mitigate ice. Some ice mitigation techniques have been tested or in use in aviation and railway sectors, however, their applicability to other sectors/systems is still in the research phase. To make such systems autonomous, ice protection systems need to be accompanied by reliable ice detection systems, which include electronic, mechatronics, mechanical, and optical techniques. Comparing the benefits and limitations of all available methodologies, Infrared Thermography (IRT) appears to be one of the useful, non-destructive, and emerging techniques as it offers wide area monitoring instead of just point-based ice monitoring. This paper reviews the applications of IRT in the field of icing on various subject areas to provide valuable insights into the existing development of an intelligent and autonomous ice mitigation system for general applications

Plasma cell gingivitis: A unique gingival lesion of unknown etiology

Gingival overgrowth is a common feature of gingival diseases, and it represents an exuberant response of the tissues to a variety of systemic and local factors. Plasma cell gingivitis (PCG), an uncommon, non-malignant lesion, is often characterized by an off ending allergen which causes a dense infi ltration of plasma cells in connective tissue. Soft tissue biopsy of affected and normal tissues is necessary for confi rmatory diagnosis.The significance of this lesion is that it may cause severe gingival infl ammation, discomfort, and bleeding with minimal trauma and may resemble more serious conditions. Here is a case of a 34-year-old female patient who presented with a solitary diff use gingival enlargement in mandibular anterior region. Overgrowth was multilobular, erythematous smooth and glossy in appearance, semicircular, non-tender with a sessile base which first gave the impression of pyogenic granuloma. The overgrowth was surgically excised and subjected to a histopathological examination that revealed a predominant plasma cell infi ltrate admixed with few neutrophils, lymphocytes, and eosinophil suggestive of PCG. The patient has been kept on follow-up and post-operatively there has been no recurrence of the lesion until date

Awareness, Knowledge, and Attitude of Saudi Students towards Basic Life Support: A Cross-Sectional Study

Objective: To evaluate the knowledge and attitude in relation to basic life support (BLS) and cardiopulmonary resuscitation (CPR) skills among the dental undergraduates and interns in Sakaka, Saudi Arabia. Material and Methods: This cross-sectional study was undertaken between October 2019 and December 2019 in Sakaka, Saudi Arabia. One hundred and eighty randomly selected dental students aged over 18 years participated in the study. Their knowledge and attitude towards BLS were gathered through a questionnaire. Results: A total of 158 (out of 180) UG students and interns participated in this study, making the responses of 87.8%. The mean age of the participants was 24.6 years. The samples comprised 86 (54.4%) males and 72 (45.6%) females. The assessments showed that overall the participants had average knowledge towards BLS and CPR, with males responding significantly better than the females (p˂0.05). Furthermore, as students climb the academic ladder, their knowledge regarding BLS and CPR tends to rise. Also, their attitude was positive, and they were willing to receive CPR training. Conclusion: Attitude toward acquiring knowledge about CPR was very positive. However, their knowledge about the topic was average. Students should understand the importance of such skills and efficiently involve in these life-saving procedures