Confirmation report of Bacterial Leaf Streak disease of rice caused by Xanthomonas oryzae pv. oryzicola in Senegal.

Xanthomonas oryzae pv. X. oryzicola (Xoc), the causal agent of Bacterial Leaf Streak (BLS), is considered as one of the most important emerging pathogens of rice in Africa. This disease is estimated as responsible of 20 to 30% yield loss (Sileshi et Gebeyehu 2021) and has been characterized in several west African countries including Mali and Burkina Faso since 2003 and more recently in Ivory Coast (Wonni et al. 2014, Diallo et al. 2021). Presence of BLS symptoms in Senegal were reported by Trinh in 1980 but, to our knowledge, BLS occurrence has never been validated further and no strain of Xoc have ever been isolated from Senegalese rice fields. Xoc is transmitted by seeds which contribute to its spread through the rice trade (Sileshi et Gebeyehu 2021). To confirm Trinh's observations, we surveyed rice fields between 2014 and 2016 in eight different regions where rice is produced in Senegal. Typical disease symptoms characterized by yellow-brown to black translucent leaf streaks sometimes along with exudates, were detected in fields of several regions and collected. Leaf pieces were successively sanitized, rinsed in sterile water, and symptomatic fragments were ground using the Qiagen Tissue Lyser System (QIAGEN, Courtaboeuf, France). The leaf powder was diluted in 1.5 ml of sterile water and incubated for 30 minutes at room temperature. Ten µl of the suspension was streaked on semi-selective PSA medium and incubated at 28°C for 3 to 7 days. Characteristic round, convex, mucous, straw-yellow Xoc candidate colonies were purified from six individual leaf samples from three distinct sites in the northern Senegal River Valley. To confirm their identity, isolated strains were tested for pathogenicity and molecular characterization. All isolates were subjected to the multiplex PCR developed for the identification of X. oryzae pathovars (Lang et al., 2010) and revealed the same PCR profile (two amplicons of 324 and 691 base pairs) similar to that of the Xoc reference strain BLS256. Leaves of 5-week-old plants of O. sativa cv. Kitaake were infiltrated with a needleless syringe containing a bacterial suspension set at an optical density of 0.5. Upon seven days of incubation under greenhouse conditions (27 ± 1°C with a 12-hour photoperiod), all infiltrated spots (2 spots on 3 plants per isolate) developed water-soaked lesions similar to those caused by control strain BLS256, except when leaves were infiltrated with water. Symptomatic leaf tissues were ground and plated on PSA medium, resulting in colonies with typical Xanthomonas morphology that were diagnosed as Xoc by multiplex PCR typing, thus fulfilling Koch's postulate. At last, four of the isolates were subjected to gyrB sequencing upon PCR amplification using the universal primers XgyrB1F and XgyrB1R (Young et al., 2008). Analysis of 780bp partial gyrB sequences of strains S18-3-4, S23-1-12, S52-1-4 and S52-1-10 highlighted 100% identity with the gyrB sequence of strain BLS256 (Acc. No. CP003057). To our knowledge, this is the first report of BLS in Senegal which is supported by molecular characterization methods. This study validates the presence of BLS in Senegal and will serve as a basis for future efforts of rice breeding for locally adapted resistance. More studies are needed to clarify the spatial distribution and prevalence of BLS in Senegal as rice cultivation is expanding rapidly in the country.

QSIRS Can Improve Accuracy of QSOFA and SIRS in Prediction of Mortality in Surgical Emergencies.

Background The quick sequential organ failure assessment (QSOFA) score and the systemic inflammatory response syndrome (SIRS) criteria were developed to predict the risk of sepsis and death in patients received in emergency. To improve sensitivity in predicting death, the association of the two scores was proposed under the term QSIRS (QSOFA + SIRS). Our aim was to determine the accuracy of QSOFA, SIRS, and QSIRS in prediction of mortality in surgical emergencies, and to compare these scores. Patients and Methods This is a prospective study over a period of 1 year. Patients older than 15 years who presented a digestive surgical emergency (bowel obstruction, peritonitis, appendicitis, strangulated hernia) were included. For each score, the specificity, the sensitivity, the positive predictive value, the negative predictive value, and areas under the receiver operating characteristic (ROC) curve (AUC) were compared. Results One hundred and eighteen patients were included and 11 deaths were recorded (9.3%). There was a statistically significant relationship between each score and death (QSOFA p = 0.01, SIRS p = 0.003, and QSIRS p = 0.004). The realization of the ROC curve found a higher AUC for QSIRS (0.845 [0.767-0.905]) compared with QSOFA (0.783 [0.698-0.854]) and SIRS (0.737 [0.648-0.813]). QSIRS (90.9%) had a higher sensitivity compared with the two other scores alone (SIRS = 81.9% and QSOFA = 36.3%). Conclusion Our study found that QSIRS improves the ability to predict death in digestive surgical emergencies.

Doxorubicin (DOX) Gadolinium-Gold-Complex: A New Way to Tune Hybrid Nanorods as Theranostic Agent.

INTRODUCTION: In this paper, we have designed and formulated, a novel synthesis of doxorubicin (DOX) loaded bimetallic gold nanorods in which gold salt (HAuCl4) is chelated with anthracycline (DOX), diacid polyethylene-glycol (PEG-COOH) and gadolinium salt (GdCl3 * 6 H2O) to form DOX IN-Gd-AuNRs compared with DOX ON-Gd-AuNRs in which the drug was grafted onto the bimetallic pegylated nanoparticle surface by electrostatic adsorption. MATERIAL AND METHOD: The physical and chemical evaluation was performed by spectroscopic analytical techniques (Raman spectroscopy, UV-Visible and transmission electron microscopy (TEM)). Magnetic features at 7T were also measured. Photothermal abilities were assessed. Cytotoxicity studies on MIA PaCa-2, human pancreatic carcinoma and TIB-75 hepatocytes cell lines were carried out to evaluate their biocompatibility and showed a 320 fold higher efficiency for DOX after encapsulation. RESULTS: Exhaustive physicochemical characterization studies were conducted showing a mid size of 20 to 40 nm diameters obtained with low polydispersity, efficient synthesis using seed mediated synthesis with chelation reaction with high scale-up, long duration stability, specific doxorubicin release with acidic pH, strong photothermal abilities at 808 nm in the NIR transparency window, strong magnetic r1 relaxivities for positive MRI, well adapted for image guided therapy and therapeutical purpose in biological tissues. CONCLUSION: In this paper, we have developed a novel theranostic nanoparticle composed of gadolinium complexes to gold ions, with a PEG biopolymer matrix conjugated with antitumoral doxorubicin, providing multifunctional therapeutic features. Particularly, these nano conjugates enhanced the cytotoxicity toward tumoral MIAPaCa-2 cells by a factor of 320 compared to doxorubicin alone. Moreover, MRI T1 features at 7T enables interesting positive contrast for bioimaging and their adapted size for potential passive targeting to tumors by Enhanced Permeability Retention. Given these encouraging antitumoral and imaging properties, this bimetallic theranostic nanomaterial system represents a veritable promise as a therapeutic entity in the field of medicinal applications.

The role of international partnerships in improving urethral reconstruction in low- and middle-income countries.

PURPOSE: To explore the impact of education and training in international surgical partnerships on outcomes of urethral stricture disease in low- and middle-income countries. To encourage data collection and outcomes assessments to promote evidence-based and safe surgical care. METHODS: Qualitative data were collected through observation of a reconstructive surgical workshop held by IVUmed at a host site in Dakar, Senegal. Quantitative data were collected through a retrospective review of 11 years of hospital data to assess surgical outcomes of urethral stricture disease before and after IVUmed started reconstructive workshops at the site. RESULTS: In the 11-year study period, 569 patients underwent 774 surgical procedures for urethral strictures. The numbers and types of urethroplasty techniques increased after IVUmed started its workshops. The average number of urethroplasties increased from 10 to 18.75/year. There was a statistically significant improvement in the mean success rate of urethroplasties from 12.7% before to 29% after the workshops. Anastomotic urethroplasty success rates doubled from 16.7 to 35.1%, but this was not statistically significant (p = 0.07). The improved success rate was sustained in cases performed without an IVUmed provider. CONCLUSIONS: Urethral stricture disease treatment in low- and middle-income countries is fraught with challenges due to complex presentations and limited subspecialty training. Improper preoperative management, lack of specialty instruments, and suboptimal wound care all contribute to poor outcomes. International surgical groups like IVUmed who employ the "teach-the-teacher" model enhance local practitioner expertise and independence leading to long-term improvements in patient outcomes. Tailoring practice guidelines to the local resource framework and encouraging data collection and outcomes assessment are vital components of providing responsible care and should be encouraged.

Identification of genes and pathways associated with aluminum stress and tolerance using transcriptome profiling of wheat near-isogenic lines.

BACKGROUND: Aluminum is considered the most limiting factor for plant productivity in acidic soils, which cover large areas of the world's potential arable lands. The inhibition of root growth is recognized as the primary effect of Al toxicity. To identify genes associated with Al stress and tolerance, transcriptome analyses of four different wheat lines (2 Al-tolerant and 2 Al sensitive) that differ in their response to Al were performed. RESULTS: Microarray expression profiling revealed that 83 candidate genes are associated with Al stress and 25 are associated with tolerance. The stress-associated genes include important enzymes such as pyruvate dehydrogenase, alternative oxidase, and galactonolactone oxidase, ABC transporter and ascorbate oxido-reducatase. The Al tolerance-associated genes include the ALMT-1 malate transporter, glutathione S-transferase, germin/oxalate oxidase, fructose 1,6-bisphosphatase, cysteine-rich proteins, cytochrome P450 monooxygenase, cellulose synthase, zinc finger transcription factor, disease resistance response protein and F-box containing domain protein. CONCLUSION: In this survey, we identified stress- and tolerance-associated genes that may be involved in the detoxification of Al and reactive oxygen species. Alternative pathways could help maintain the supply of important metabolites (H2O2, ascorbate, NADH, and phosphate) needed for Al tolerance and root growth. The Al tolerance-associated genes may be key factors that regulate these pathways.

TaVRT2 represses transcription of the wheat vernalization gene TaVRN1.

In wheat, VRN1/TaVRN1 and VRN2/TaVRN2 determine the growth habit and flowering time. In addition, the MADS box transcription factor VEGETATIVE TO REPRODUCTIVE TRANSITION 2 (TaVRT2) is also associated with the vernalization response in a manner similar to TaVRN2. However, the molecular relationship between these three genes and their products is unknown. Using transient expression assays in Nicotiana benthamiana, we show that TaVRT2 acts as a repressor of TaVRN1 transcription. TaVRT2 binds the CArG motif in the TaVRN1 promoter and represses its activity in vivo. In contrast, TaVRN2 does not bind the TaVRN1 promoter and has no direct effect on its activity, but it can enhance the repression effect of TaVRT2. This suggests that a repressor complex regulates the expression of TaVRN1. In winter wheat, TaVRT2, TaVRN2 and TaVRN1 transcripts accumulate in the shoot apical meristem and young leaves, and temporal expression is consistent with TaVRT2 and TaVRN2 being repressors of floral transition, whereas TaVRN1 is an activator. Non-vernalized spring wheat grown under a short-day photoperiod accumulates TaVRT2 and shows a delay in flowering, suggesting that TaVRT2 is regulated independently by photoperiod and low temperature. The data presented suggest that TaVRT2, in association with TaVRN2, represses the transcription of TaVRN1.