Development of a DNA damage-induced senescence model in osteoarthritic chondrocytes

Senescent cells (SnCs) have been described to accumulate in osteoarthritis (OA) joint tissues in response to injury, thereby participating in OA development and progression. However, clinical therapeutic approaches targeting SnCs using senolysis, although promising in preclinical OA models, have not yet proven their efficacy in patients with knee OA. This pitfall may be due to the lack of understanding of the mechanisms underlying chondrocyte senescence. Therefore, our study aimed to generate models of chondrocyte senescence. This study used etoposide, to induce DNA damage-related senescence or chronic exposure to IL-1β to entail inflammation-related senescence in human OA chondrocytes. Several hallmarks of cellular senescence, such as cell cycle arrest, expression of cyclin-dependent kinase inhibitors, DNA damages, and senescence-associated secretory profile were evaluated. Chronic exposure to IL-1β induces only partial expression of senescence markers and does not allow us to conclude on its ability to induce senescence in chondrocytes. On the other hand, etoposide treatment reliably induces DNA damage-related senescence in human articular chondrocytes evidenced by loss of proliferative capacity, DNA damage accumulation, and expression of some SASP components. Etoposide-induced senescence model may help investigate the initiation of cellular senescence in chondrocytes, and provide a useful model to develop therapeutic approaches to target senescence in OA.

Silanization of Chitosan and Hydrogel Preparation for Skeletal Tissue Engineering

Tissue engineering is a multidisciplinary field that relies on the development of customized biomaterial to support cell growth, differentiation and matrix production. Toward that goal, we designed the grafting of silane groups onto the chitosan backbone (Si-chito) for the preparation of in situ setting hydrogels in association with silanized hydroxypropyl methylcellulose (Si-HPMC). Once functionalized, the chitosan was characterized, and the presence of silane groups and its ability to gel were demonstrated by rheology that strongly suggests the presence of silane groups. Throughout physicochemical investigations, the Si-HPMC hydrogels containing Si-chito were found to be stiffer with an injection force unmodified. The presence of chitosan within the hydrogel has demonstrated a higher adhesion of the hydrogel onto the surface of tissues. The results of cell viability assays indicated that there was no cytotoxicity of Si-chito hydrogels in 2D and 3D culture of human SW1353 cells and human adipose stromal cells, respectively. Moreover, Si-chito allows the transplantation of human nasal chondrocytes in the subcutis of nude mice while maintaining their viability and extracellular matrix secretory activity. To conclude, Si-chito mixed with Si-HPMC is an injectable, self-setting and cytocompatible hydrogel able to support the in vitro and in vivo viability and activity of hASC.

A Self-Setting Hydrogel of Silylated Chitosan and Cellulose for the Repair of Osteochondral Defects: From in vitro Characterization to Preclinical Evaluation in Dogs

Articular cartilage (AC) may be affected by many injuries including traumatic lesions that predispose to osteoarthritis. Currently there is no efficient cure for cartilage lesions. In that respect, new strategies for regenerating AC are contemplated with interest. In this context, we aim to develop and characterize an injectable, self-hardening, mechanically reinforced hydrogel (Si-HPCH) composed of silanised hydroxypropymethyl cellulose (Si-HPMC) mixed with silanised chitosan. The in vitro cytocompatibility of Si-HPCH was tested using human adipose stromal cells (hASC). In vivo, we first mixed Si-HPCH with hASC to observe cell viability after implantation in nude mice subcutis. Si-HPCH associated or not with canine ASC (cASC), was then tested for the repair of osteochondral defects in canine femoral condyles. Our data demonstrated that Si-HPCH supports hASC viability in culture. Moreover, Si-HPCH allows the transplantation of hASC in the subcutis of nude mice while maintaining their viability and secretory activity. In the canine osteochondral defect model, while the empty defects were only partially filled with a fibrous tissue, defects filled with Si-HPCH with or without cASC, revealed a significant osteochondral regeneration. To conclude, Si-HPCH is an injectable, self-setting and cytocompatible hydrogel able to support the in vitro and in vivo viability and activity of hASC as well as the regeneration of osteochondral defects in dogs when implanted alone or with ASC.

Preliminary evaluation of an osteochondral autograft, a prosthetic implant, and a biphasic absorbable implant for osteochondral reconstruction in a sheep model

OBJECTIVE

To determine the ability of three implants to enhance the healing of osteochondral defects: (1) a biphasic construct composed of calcium phosphate (CaP) and chitosan/cellulosic polymer, (2) a titanium-polyurethane implant, and (3) an osteochondral autograft.

STUDY DESIGN

Experimental study.

ANIMALS

Ten adult female sheep.

METHODS

In five sheep, an 8-mm diameter osteochondral defect was created on the medial femoral condyle of a stifle and filled with a synthetic titanium-polyurethane implant. In five sheep, a similar defect was filled with an osteochondral autograft, and the donor site was filled with a biphasic construct combining CaP granules and a chitosan/cellulosic polymer. Sheep were monitored daily for lameness. Stifle radiographs and MRI were evaluated at 20 weeks, prior to animals being humanely killed. Surgical sites were evaluated with histology, microcomputed tomography, and scanning electron microscopy.

RESULTS

Clinical outcomes were satisfactory regardless of the tested biomaterials. All implants appeared in place on imaging studies. Osteointegration of prosthetic implants varied between sites, with limited ingrowth of new bone into the titanium structure. Autografts and biphasic constructs were consistently well integrated in subchondral bone. All autografts except one contained a cartilage surface, and all biphasic constructs except one partially restored hyaline cartilage surface.

CONCLUSION

Biphasic constructs supported hyaline cartilage and subchondral bone regeneration, although restoration of the articular cartilage was incomplete.

CLINICAL IMPACT

Biphasic constructs may provide an alternative treatment for osteochondral defects, offering a less invasive approach compared with autologous grafts and eliminating the requirement for a prosthetic implant.

Dosimetric and microdosimetric analyses for blood exposed to reactor-derived thermal neutrons

Thermal neutrons are found in reactor, radiotherapy, aircraft, and space environments. The purpose of this study was to characterise the dosimetry and microdosimetry of thermal neutron exposures, using three simulation codes, as a precursor to quantitative radiobiological studies using blood samples. An irradiation line was designed employing a pyrolytic graphite crystal or-alternatively-a super mirror to expose blood samples to thermal neutrons from the National Research Universal reactor to determine radiobiological parameters. The crystal was used when assessing the relative biological effectiveness for dicentric chromosome aberrations, and other biomarkers, in lymphocytes over a low absorbed dose range of 1.2-14 mGy. Higher exposures using a super mirror will allow the additional quantification of mitochondrial responses. The physical size of the thermal neutron fields and their respective wavelength distribution was determined using the McStas Monte Carlo code. Spinning the blood samples produced a spatially uniform absorbed dose as determined from Monte Carlo N-Particle version 6 simulations. The major part (71%) of the total absorbed dose to blood was determined to be from the ¹⁴N(n,p)¹⁴C reaction and the remainder from the ¹H(n,γ)²H reaction. Previous radiobiological experiments at Canadian Nuclear Laboratories involving thermal neutron irradiation of blood yielded a relative biological effectiveness of 26 ± 7. Using the Particle and Heavy Ion Transport Code System, a similar value of ∼19 for the quality factor of thermal neutrons initiating the ¹⁴N(n,p)¹⁴C reaction in soft tissue was determined by microdosimetric simulations. This calculated quality factor is of similar high value to the experimentally-derived relative biological effectiveness, and indicates the potential of thermal neutrons to induce deleterious health effects in superficial organs such as cataracts of the eye lens.

Clinical Application of a Chromogenic Substrate Method for Determination of Factor VIII Activity

A chromogenic substrate kit for the determination of factor VIII activity (COATEST® Factor VIII) has been evaluated in five different laboratories, one of them using a semi-automated procedure. This chromogenic method was compared to one-stage clotting assays for factor VIII determination in plasmas from healthy subjects, carriers of hemophilia A, severe, mild and moderate hemophilia A as well as von Willebrand’s patients. In all these cases, a high correlation between these two methods was obtained (r = 0.96-0.99, n = 385) with a good agreement of the assigned potencies at all levels of factor VIII. A good correlation (r = 0.94) was also obtained for the levels of factor VIII after infusion of concentrates in six severe hemophiliacs or after administration of DDAVP to von Willebrand’s patients.

The chromogenic method is insensitive to preactivation of factor VIII by thrombin, thus yielding valid potency assignments also in these situations.

The precision was higher with the chromogenic method than with the one-stage clotting assays (C.V. = 2-5% vs 4-15%). Altogether, the new chromogenic substrate method has proven itself suitable for determination of factor VIII in plasma and concentrates.

An Enzyme Immunoassay (ELISA) for the Quantitation of Human Factor VII

A new solid phase enzyme-linked immunosorbent assay (ELISA) was developed for the quantitation of human Factor VII antigen (F VII Ag), using a monospecific rabbit anti-F VII antiserum. Anti-F VII F(ab′)2 fragments were adsorbed to polystyrene plates. The binding of serial dilutions of control or test plasma, containing F VII, was detected by incubation with peroxidase-labeled anti- FV II IgG followed by the addition of hydrogen peroxyde and O-phenylenediamine. This ELISA is specific, sensitive (detection limit: 0.05%) and accurate (coefficient of variation: 1.5-4% for within- and 1.6-9% for between-assays). F VII coagulant activity (F VII C) and F VII Ag were determined in large populations of controls and patients. In normal plasma (n = 38), F VII Ag ranged from 83 to 117% and the correlation coefficient between F VII Ag and F VII C was 0.94. In patients with severe (F VII C inf. 1%) congenital F VII deficiency (n = 5), F VII Ag was undetectable in two cases (inf. 0.05%) and markedly reduced (0.35 to 5.6%) in the three other cases. In patients with liver cirrhosis (n = 15), F VII Ag ranged from 21 to 59% and was in good correlation with F VII C (r = 0.84). In dicoumarol treated patients (n = 15), the levels of F VII Ag ranged from 51% to 79% and a poor correlation (r = 0.52) with F VIIC was observed. In “compensated” DIC (n = 5), levels of F VII Ag varied from 60 to 186%, with significantly higher F VII C levels (from 143 to 189%). In contrast, in “decompensated” DIC (n = 7), low F VII Ag and F VII C levels were observed (from 7 to 27%). In patients with deep-vein thrombosis (n = 25), high levels of F VII Ag (from 102 to 136%) and F VII C (from 110 to 150%) were demonstrated. In surgical patients, no significant difference was observed before and one day after intervention.

Homozygous Variant of Antithrombin III : AT III Fontainebleau

A qualitative defect of antithrombin III (AT III) was demonstrated in four members of a large Tunisian family by the discrepancy between a normal amount of antigen and decreased or absent heparin cofactor activity. The propositus, a 3-year-old girl, died from massive intracardiac thrombosis despite oral anticoagulant therapy. Heparin cofactor activity measured in the presence of thrombin or F. Xa was undetectable in her plasma. Anti-F. Xa activity was also absent when using low molecular weight heparin or a synthetic pentasaccharide, representing the binding site to AT III. The lack of affinity of the propositus AT III for heparin was demonstrated by two-dimensional immunoelectrophoresis and chromatography on heparin-Sepha-rose. The parents, first cousins, and the sister of the propositus also demonstrated a qualitative abnormality of AT III, with levels of heparin cofactor activity close to 50% of the normal range. Our data support the view that the abnormal protein was present at the heterozygous state in the parents and sister and at the homozygous state in the propositus. None of the affected family members had thrombotic episodes, except for the propositus. The name of AT III Fontainebleau is proposed for this variant.

Multicenter Comparison of Five Functional and Two Immunological Assays for Protein C

Five functional assays and two immunoassays for protein C (PC) were evaluated in parallel for the same plasma samples collected from healthy subjects, patients with congenital and acquired PC deficiencies or patients with conditions associated with high PC levels. For 7 patients starting warfarin therapy and for 15 patients during stabilized warfarin therapy, there were significant between-assay differences. For these groups immunoassays gave higher values than most functional assays and the latter also gave varied results, probably depending on their respective capacity for recognizing acarboxylated PC. On the other hand, there were no significant between-assay differences nor discrepancies between PC activity and antigen levels for healthy subjects (n = 39), patients with congenital PC deficiency (n = 10), myocardial infarction (n = 25), chronic liver disease (n = 19), disseminated intravascular coagulation (n = 35), in the post-operative period (n = 20) or in women taking oral contraceptives (n = 20). This comparison of PC assays indicates that PC levels measured by different functional or immunological assays are very close in the majority of clinical conditions, but not for patients on oral anticoagulants.

A Cellulose/Laponite Interpenetrated Polymer Network (IPN) Hydrogel: Controllable Double-Network Structure with High Modulus

Laponite XLS™, which is a synthetic clay of nanometric dimensions containing a peptizing agent, has been associated with silanized hydroxypropylmethylcellulose (Si-HPMC) to form, after crosslinking, a novel composite hydrogel. Different protocols of sample preparation were used, leading to different morphologies. A key result was that the storage modulus of Si-HPMC/XLS composite hydrogel could be increased ten times when compared to that of pure Si-HPMC hydrogel using 2 wt % of Laponite. The viscoelastic properties of the composite formulations indicated that chemical and physical network structures co-existed in the Si-HPMC/XLS composite hydrogel. Images that were obtained from confocal laser scanning microscopy using labelled Laponite XLS in the composite hydrogels show two co-continuous areas: red light area and dark area. The tracking of fluorescent microspheres motions in the composite formulations revealed that the red-light area was a dense structure, whereas the dark area was rather loose without aggregated Laponite. This novel special double-network structure facilitates the composite hydrogel to be an adapted biomaterial for specific tissue engineering. Unfortunately, cytotoxicity’s assays suggested that XLS Laponites are cytotoxic at low concentration. This study validates that the hybrid interpenetrated network IPN hydrogel has a high modulus that has adapted for tissue engineering, but the cell’s internalization of Laponites has to be controlled.

Education and Consumer Informatics

Objectives: To evaluate the extent to which the Internet is accessed for health information and perceived as useful to varying groups classified primarily according to age.

Method: Synopsis of the articles on education and consumer health informatics selected for the IMIA Yearbook of Medical Informatics 2010.

Results: A growing number of individuals are actively seeking health information through a varying selection of resources. The Internet is now seen as a major source of health information alongside with books and other means of paper-based literature. However, it is not clear how the Internet is perceived by varied groups such as those coming from differing age groups.

Conclusion: The papers selected attempt to obtain a better understanding about how the public perceives and uses the Internet as an information gathering tool—especially for health information. The papers also explore into how the Internet is used by different groups of people. As all online health information is not of uniform quality, it is important to access and rely on quality medical information. This issue is also dealt with, where the popularity of Wikipedia is measured with the popularity of reliable web sources such as Medline Plus and NHS Direct.

A Humanist’s Legacy in Medical Informatics: Visions and Accomplishments of Professor Jean-Raoul Scherrer

Objective: To report about the work of Prof. Jean-Raoul Scherrer, and show how his humanist vision, his medical skills and his scientific background have enabled and shaped the development of medical informatics over the last 30 years.

Results: Starting with the mainframe-based patient-centered hospital information system DIOGENE in the 70s, Prof. Scherrer developed, implemented and evolved innovative concepts of man-machine interfaces, distributed and federated environments, leading the way with information systems that obstinately focused on the support of care providers and patients. Through a rigorous design of terminologies and ontologies, the DIOGENE data would then serve as a basis for the development of clinical research, data mining, and lead to innovative natural language processing techniques. In parallel, Prof. Scherrer supported the development of medical image management, ranging from a distributed picture archiving and communication systems (PACS) to molecular imaging of protein electrophoreses. Recognizing the need for improving the quality and trustworthiness of medical information on the Web, Prof. Scherrer created the Health-On-the-Net (HON) foundation.

Conclusions: These achievements, made possible thanks to his visionary mind, deep humanism, creativity, generosity and determination, have made of Prof. Scherrer a true pioneer and leader of the human-centered, patient-oriented application of information technology for improving healthcare.

Laponite nanoparticle-associated silated hydroxypropylmethyl cellulose as an injectable reinforced interpenetrating network hydrogel for cartilage tissue engineering

Articular cartilage is a connective tissue which does not spontaneously heal. To address this issue, biomaterial-assisted cell therapy has been researched with promising advances. The lack of strong mechanical properties is still a concern despite significant progress in three-dimensional scaffolds. This article's objective was to develop a composite hydrogel using a small amount of nano-reinforcement clay known as laponites. These laponites were capable of self-setting within the gel structure of the silated hydroxypropylmethyl cellulose (Si-HPMC) hydrogel. Laponites (XLG) were mixed with Si-HPMC to prepare composite hydrogels leading to the development of a hybrid interpenetrating network. This interpenetrating network increases the mechanical properties of the hydrogel. The in vitro investigations showed no side effects from the XLG regarding cytocompatibility or oxygen diffusion within the composite after cross-linking. The ability of the hybrid scaffold containing the composite hydrogel and chondrogenic cells to form a cartilaginous tissue in vivo was investigated during a 6-week implantation in subcutaneous pockets of nude mice. Histological analysis of the composite constructs revealed the formation of a cartilage-like tissue with an extracellular matrix containing glycosaminoglycans and collagens. Overall, this new hybrid construct demonstrates an interpenetrating network which enhances the hydrogel mechanical properties without interfering with its cytocompatibility, oxygen diffusion, or the ability of chondrogenic cells to self-organize in the cluster and produce extracellular matrix components. This composite hydrogel may be of relevance for the treatment of cartilage defects in a large animal model of articular cartilage defects.

STATEMENT OF SIGNIFICANCE

Articular cartilage is a tissue that fails to heal spontaneously. To address this clinically relevant issue, biomaterial-assisted cell therapy is considered promising but often lacks adequate mechanical properties. Our objective was to develop a composite hydrogel using a small amount of nano reinforcement (laponite) capable of gelling within polysaccharide based self-crosslinking hydrogel. This new hybrid construct demonstrates an interpenetrating network (IPN) which enhances the hydrogel mechanical properties without interfering with its cytocompatibility, O₂ diffusion and the ability of chondrogenic cells to self-organize in cluster and produce extracellular matrix components. This composite hydrogel may be of relevance for the treatment of cartilage defects and will now be considered in a large animal model of articular cartilage defects.

[Cancer plans apply to surgical treatment of prostate cancer: A geographically isolated center balance]

INTRODUCTION

Since 2003, fight against cancer was structured by 3 national cancer programs (CP). The objective of this study is to evaluate the application of these measures in the case of surgical prostate cancer (PCa) treatment in a geographically isolated center.

MATERIAL

Monocentric retrospective study carried in a 100-bed clinic located 2hours away from a Cancer Regional Reference Center. Between August 2009 and December 2014, 251 consecutive patients were treated by total laparoscopic prostatectomy (TLP). Fifty-seven patients (22.7 %) received a secondary treatment after TLP. The study focused on the delay between prostate biopsies and PTL, the traceability of AD elements, the return of active patients, inclusion in clinical trials (GETUG 17, GETUG 20 and GETUG 22). Data were collected in September 2016. The follow-up defined by the time between the date of the last visit and the prostate biopsy allows a median follow-up of 43.1 months (2.4-80.5).

RESULTS

All elements of the CAP are totally gathered on 45 % of the patients (113/251). Thirty-four (13.5 %) patients were active at the time of the intervention. Thirty-one (91.2 %) will return to an identical activity after a median work stoppage of 1.7 month (0.25-6). Fourteen percent (35/251) of the patients are eligible to a clinical trial. Seventeen percent (6/35) of them were proposed to one of a trial after multidisciplinary meeting and 5.7 % (2/35) are eventually included in one trial.

CONCLUSION

CP define a course of high quality care. A better transparency of the founding of the enforceable measures and a better consideration for the local specificities should facilitate their application. The TLP treat the PCa with the reasonable objective of a return to an identical professional activity. The multidisciplinary meeting does not guarantee the participation to clinical trial, which depends mainly on distance from the Cancer Regional Reference Center and the vigilance of the Urologist.

LEVEL OF EVIDENCE

4.

Adaptation of genetically monomorphic bacteria: evolution of copper resistance through multiple horizontal gene transfers of complex and versatile mobile genetic elements

Copper-based antimicrobial compounds are widely used to control plant bacterial pathogens. Pathogens have adapted in response to this selective pressure. Xanthomonas citri pv. citri, a major citrus pathogen causing Asiatic citrus canker, was first reported to carry plasmid-encoded copper resistance in Argentina. This phenotype was conferred by the copLAB gene system. The emergence of resistant strains has since been reported in Réunion and Martinique. Using microsatellite-based genotyping and copLAB PCR, we demonstrated that the genetic structure of the copper-resistant strains from these three regions was made up of two distant clusters and varied for the detection of copLAB amplicons. In order to investigate this pattern more closely, we sequenced six copper-resistant X. citri pv. citri strains from Argentina, Martinique and Réunion, together with reference copper-resistant Xanthomonas and Stenotrophomonas strains using long-read sequencing technology. Genes involved in copper resistance were found to be strain dependent with the novel identification in X. citri pv. citri of copABCD and a cus heavy metal efflux resistance-nodulation-division system. The genes providing the adaptive trait were part of a mobile genetic element similar to Tn3-like transposons and included in a conjugative plasmid. This indicates the system's great versatility. The mining of all available bacterial genomes suggested that, within the bacterial community, the spread of copper resistance associated with mobile elements and their plasmid environments was primarily restricted to the Xanthomonadaceae family.

Comparison of ActiGraph GT3X+ and Actical accelerometer data in 9-11-year-old Canadian children

Accelerometry is the gold standard for field-based physical activity assessment in children; however, the plethora of devices, data reduction procedures, and cut-points available limits comparability between studies. This study aimed to compare physical activity variables from the ActiGraph GT3X+ and Actical accelerometers in children under free-living conditions. A cross-sectional study of 379 children aged 9-11 years from Ottawa (Canada) was conducted. Children wore the ActiGraph GT3X+ and Actical accelerometers on the hip simultaneously for 7 consecutive days (24-h protocol). Moderate-to-vigorous (MVPA), vigorous (VPA), moderate (MPA), and light (LPA) physical activity, as well as sedentary time, (SED) were derived using established data reduction protocols. Excellent agreement between devices was observed for MVPA (ICC = 0.73-0.80), with fair to good agreement for MPA, LPA and SED, and poor agreement for VPA. Bland-Altman plots showed excellent agreement for MVPA, LPA, and SED, adequate agreement for MPA, and poor agreement for VPA. MVPA derived from the Actical was 11.7% lower than the ActiGraph GT3X+. The ActiGraph GT3X+ and Actical are comparable for measuring children's MVPA. However, comparison between devices for VPA, MPA, LPA, and SED are highly dependent on data reduction procedures and cut-points, and should be interpreted with caution.

Natural Infection of Cashew (Anacardium occidentale) by Xanthomonas citri pv. mangiferaeindicae in Burkina Faso

Xanthomonas citri pv. mangiferaeindicae is the causal agent of bacterial canker of mango (Mangifera indica, Anacardiaceae), a disease of international importance. Since the original description of the bacterium in the 1940s, the status of cashew (Anacardium occidentale, Anacardiaceae) as a host species has been unclear. Here, we report the first outbreak of a cashew bacterial disease in Burkina Faso (Western Africa) where X. citri pv. mangiferaeindicae recently emerged on mango. A comprehensive molecular characterization, based on multilocus sequence analysis, supplemented with pathogenicity assays of isolates obtained during the outbreak, indicated that the causal agent on cashew in Burkina Faso is X. citri pv. mangiferaeindicae and not X. citri pv. anacardii, which was previously reported as the causal agent of a cashew bacterial leaf spot in Brazil. Pathogenicity data supported by population biology in Burkina Faso suggest a lack of host specialization. Therefore, the inoculum from each crop is potentially harmful to both host species. Symptoms induced on cashew leaves and fruit by X. citri pv. mangiferaeindicae and nonpigmented strains of X. citri pv. anacardii are similar, although the causative bacteria are genetically different. Thus, xanthomonads pathogenic on cashew may represent a new example of pathological convergence in this bacterial genus.

First Report of Xanthomonas citri pv. mangiferaeindicae Causing Mango Bacterial Canker on Mangifera indica in Ivory Coast

Xanthomonas citri pv. mangiferaeindicae causing bacterial canker (or black spot) is a major mango (Mangifera indica L.) pathogen in tropical and subtropical areas (3). The bacterium infects a wide range of mango cultivars, and induces raised, angular, black leaf lesions, sometimes with a yellow chlorotic halo. Fruit symptoms first appear as small water-soaked spots on the lenticels turning into star-shaped, erumpent lesions, which exude an infectious gum, yielding tear-stain patterns. Severe infections cause severe defoliation and/or premature fruit drop. Twig cankers are potential sources of inoculum and weaken branch resistance to winds. Drastic yield losses have been reported at grove scale for susceptible cultivars (3). Mango leaves showing typical angular, black, raised leaf lesions were first observed and collected in April 2014 from trees cv. Kent in five localities of the Korhogo province of Ivory Coast (i.e., the major commercial mango-growing area in this country). Non-pigmented Xanthomonas-like colonies were isolated on KC semi-selective medium (4). Five strains (LL60-1, LL61-1, LL62-1, LL63-1, and LL64-1), one from each locality, were compared by multilocus sequence analysis (MLSA) to the type strain of X. citri and the pathotype strain of several X. citri pathovars, including pvs. anacardii and mangiferaeindicae. This assay targeted the atpD, dnaK, efp, and gyrB genes, as described previously (2). Nucleotide sequences were 100% identical to those of the pathotype strain of X. citri pv. mangiferaeindicae whatever the gene assayed, but differed from any other assayed X. citri pathovar. Leaves of mango cv. Maison Rouge from the youngest vegetative flush were infiltrated (10 inoculation sites/leaf for three replicate leaves on different plants/bacterial strain) as detailed previously (1) with the same five strains. Bacterial suspensions (~1 × 10⁵ cfu/ml) were prepared in 10 mM Tris buffer (pH 7.2) from 16-h-old cultures on YPGA (7 g yeast, 7 g peptone, 7 g glucose, and 18 g agar/liter, pH 7.2). The negative control treatment consisted of three leaves infiltrated with sterile Tris buffer (10 sites/leaf). Plants were incubated in a growth chamber at 30 ± 1°C by day and 26 ± 1°C by night (12-h day/night cycle) at 80 ± 5% RH. All leaves inoculated with the strains from Ivory Coast showed typical symptoms of bacterial canker a week after inoculation. No lesions were recorded from the negative controls. The pathogen was recovered at high population densities (>1 × 10⁶ cfu/lesion) from leaf lesions, typical of a compatible interaction (1) and isolated colonies were identified as the target by atpD sequencing (2). Koch's postulates have therefore been fully verified. This is the first report of the disease in Ivory Coast, a country which has been an internationally significant mango exporter (up to 15,000 tons per year) over the last two decades. A high disease incidence and severity were observed, outlining the need for implementing integrated pest management in mango groves and the production of disease-free nursery stock. This report further expands the distribution of the pathogen in West Africa after its first description from Ghana in 2011 (5) and subsequently in other neighboring countries. References: (1) N. Ah-You et al. Phytopathology 97:1568, 2007. (2) L. Bui Thi Ngoc et al. Int. J. Syst. Evol. Microbiol. 60:515, 2010. (3) L. Gagnevin and O. Pruvost. Plant Dis. 85:928, 2001. (4) O. Pruvost et al. J. Appl. Microbiol. 99:803, 2005. (5) O. Pruvost et al. Plant Dis. 95:774, 2011.

First Report of Xanthomonas citri pv. citri Pathotype A Causing Asiatic Citrus Canker in Grande Comore and Anjouan

The causal agent of Asiatic citrus canker, Xanthomonas citri pv. citri, is a bacterium of major economic importance in tropical and subtropical citrus-producing areas. X. citri pv. citri pathotype A can cause severe infection in a wide range of citrus species and induces erumpent, callus-like lesions with water-soaked margins evolving to corky cankers and leading to premature fruit, leaf drop, and twig dieback on susceptible cultivars. This quarantine organism can strongly impact citrus markets so it has consequently been subjected to eradication efforts and international quarantine regulations. Asiatic citrus canker occurs on most islands in the Southwest Indian Ocean region including the Mascarene and Seychelles archipelagos. In the Comoros archipelago, the disease was observed for the first time in Mohéli island in 1966 (2), but had not yet been reported in neighboring islands, Grande Comore and Anjouan. In September 2013, leaves of key lime (Citrus aurantifolia) and sweet orange (C. sinensis) showing symptoms of citrus canker were collected from Anjouan, Grande Comore, and Mohéli. Nine Xanthomonas-like strains (three from each of the three islands) were isolated using KC semi-selective medium (5) from diseased samples (LK126-3, LK127-7, LK128-2, LK131-10, LK137-1, LK141-3, LK144-5, LK145-5, LK146-2). Based on a specific PCR assay with 4/7 primers (4), all Xanthomonas-like strains were tentatively identified as X. citri pv. citri. All strains produced a 468-bp amplicon similar to X. citri pv. citri strain IAPAR 306 used as a positive control. Negative control reactions with sterile tris buffer did not produce amplicons. Multilocus sequence analysis (MLSA) targeting six housekeeping genes (atpD, dnaK, efp, gltA, gyrB, and lepA) (1,3) fully identified all strains from the Comoros as X. citri pv. citri. More specifically, eight strains were identified as sequence type ST2 composed of pathotype A strains of X. citri pv. citri (3) (including all strains from the Southwest Indian Ocean region) while one of them (LK141-3 from Mohéli) was identified as a new sequence type based on a non-synonymous single nucleotide polymorphism in gyrB (accession KJ941208). All strains were inoculated by a detached leaf assay (3) onto Mexican lime SRA 140 (C. aurantifolia), Tahiti lime SRA 58 (C. latifolia), sweet orange New Hall Navel SRA 343 (C. sinensis), grapefruit Henderson SRA 336 (C. paradisi), and Ortanique tangor SRA 110 (C. reticulata × C. sinensis). All citrus species inoculated produced typical erumpent, callus-like tissue at wound sites. Xanthomonas-like yellow colonies were re-isolated from lesions produced on Mexican lime. Boiled bacterial suspensions were assayed by PCR with 4/7 primers (4) and produced the expected amplicon, fulfilling Koch's postulates. No lesions developed on the negative control consisting of inoculations with sterile tris buffer. This is the first report of X. citri pv. citri-A causing Asiatic citrus canker in Grande Comore and Anjouan islands confirming the wide distribution of the pathogen in Southwest Indian Ocean islands. Canker-free nurseries and grove sanitation should be implemented to decrease the prevalence of Asiatic canker in the Comoros. References: (1) N. F. Almeida et al. Phytopathology 100:208, 2010. (2) J. Brun. Fruits 26:533, 1971. (3) L. Bui Thi Ngoc et al. Int. J. Syst. Evol. Microbiol. 60:515, 2010. (4) J. S. Hartung et al. Phytopathology 86:95, 1996. (5) O. Pruvost et al. J. Appl. Microbiol. 99:803, 2005.

First Report of Xanthomonas citri pv. citri Causing Asiatic Citrus Canker in Burkina Faso

Citrus canker, caused by Xanthomonas citri pv. citri, is a bacterial disease of economic importance in tropical and sub-tropical citrus-producing areas (EPPO-PQR online database). X. citri pv. citri causes severe infection in a wide range of citrus species, and induces erumpent, callus-like lesions with water-soaked margins leading to premature fruit drop and twig dieback. It has consequently been subjected to eradication efforts and international regulations. It was first described on the African continent in South Africa at the beginning of the 20th century, from which it was eventually eradicated. Since 2006, several outbreaks caused by phylogenetically diverse strains of X. citri pv. citri have been reported from several African countries (Ethiopia, Mali, Senegal, and Somalia). In July 2011, citrus canker in Burkina Faso was suspected in the area adjacent to the Sikassso Province of Mali where X. citri pv. citri has been confirmed. In November and December 2012, leaves of clementine (Citrus clementina), lemon (C. limon), Volkamer lemon (C. volkameriana), sweet orange (C. sinensis), tangelo (C. paradisi× C. reticulata), and mandarin (C. reticulata) were collected from orchards with trees showing symptoms of citrus canker in the Comoé, Houet, and Kénédougou provinces of Burkina Faso. Isolations performed using KC semi-selective medium (4) recovered 45 Xanthomonas-like strains. All Xanthomonas-like strains were tentatively identified as X. citri pv. citri by PCR (4/7 primers) using IAPAR 306 and sterile distilled water as the positive and negative controls, respectively (3). Among these, two strains (LK4-4 and LK4-5) produced a 'fuscans'-like brown diffusible pigment, a phenotype never reported previously for X. citri pv. citri. MultiLocus Sequence Analysis targeting six housekeeping genes (atpD, dnaK, efp, gltA, gyrB, and lepA) (1,2) fully identified seven strains from Burkina Faso (LJ301-1, LJ303-1, LK1-1, LK2-6, LK4-3, LK4-4, and LK4-5) as X. citri pv. citri (and not to any other Xanthomonas pathovars pathogenic to citrus or host range-restricted pathotypes of pathovar citri), and more specifically as sequence type ST2 which is composed mostly of pathotype A strains of X. citri pv. citri (2). The same seven strains were inoculated to at least four leaves of each of grapefruit cv. Henderson, Mexican lime SRA 140 (C. aurantifolia), Tahiti lime SRA 58 (C. latifolia), and sweet orange cv. Washington Navel, using a detached leaf assay (2). All strains developed typical erumpent, callus-like tissue at wound sites on all citrus species inoculated. No lesions developed on the negative control (sterile 10 mM tris buffer). Koch's postulate was fulfilled after reisolation of Xanthomonas-like yellow colonies from symptoms on Mexican lime produced by the seven strains. Boiled bacterial suspensions were assayed by PCR with 4/7 primers (3) and produced the expected 468-bp amplicon in contrast with the PCR negative control. To our knowledge, this is the first report of X. citri pv. citri in Burkina Faso. Citrus canker-free nurseries and grove sanitation should be implemented for reducing the prevalence of Asiatic canker in Burkina Faso and a thorough survey of citrus nurseries and groves in the region should be conducted. References: (1) N. F. Almeida et al. Phytopathology 100:208, 2010. (2) L. Bui Thi Ngoc et al. Int. J. Syst. Evol. Microbiol. 60:515, 2010. (3) J. S. Hartung et al. Phytopathology 86:95, 1996. (4) O. Pruvost et al. J. Appl. Microbiol. 99:803, 2005.

Nanocomposite hydrogels for cartilage tissue engineering: mesoporous silica nanofibers interlinked with siloxane derived polysaccharide

Injectable materials for mini-invasive surgery of cartilage are synthesized and thoroughly studied. The concept of these hybrid materials is based on providing high enough mechanical performances along with a good medium for chondrocytes proliferation. The unusual nanocomposite hydrogels presented herein are based on siloxane derived hydroxypropylmethylcellulose (Si-HPMC) interlinked with mesoporous silica nanofibers. The mandatory homogeneity of the nanocomposites is checked by fluorescent methods, which show that the silica nanofibres dispersion is realized down to nanometric scale, suggesting an efficient immobilization of the silica nanofibres onto the Si-HPMC scaffold. Such dispersion and immobilization are reached thanks to the chemical affinity between the hydrophilic silica nanofibers and the pendant silanolate groups of the Si-HPMC chains. Tuning the amount of nanocharges allows tuning the resulting mechanical features of these injectable biocompatible hybrid hydrogels. hASC stem cells and SW1353 chondrocytic cells viability is checked within the nanocomposite hydrogels up to 3 wt% of silica nanofibers.

First Report of Xanthomonas citri pv. citri-A Causing Asiatic Citrus Canker in Mayotte

Asiatic citrus canker, caused by Xanthomonas citri pv. citri, is a bacterial disease of major economic importance in tropical and subtropical citrus-producing areas. X. citri pv. citri pathotype A can cause severe infection in a wide range of citrus species and induces erumpent, callus-like lesions with water-soaked margins evolving to corky cankers and leading to premature fruit and leaf drop and twig dieback on susceptible/very susceptible cultivars. A chlorotic halo is typically visible around canker lesions on leaves and young fruit, but not on mature fruit and twigs. This quarantine organism can strongly impact both national and international citrus markets. Long distance dispersal is mainly through infected propagative material. Asiatic citrus canker occurs on most islands in the Southwest Indian Ocean region (Comoros, Mauritius, Reunion, Rodrigues, and Seychelles islands), but was not yet reported in Mayotte (EPPO-PQR available at http://www.eppo.int ). In May 2012, typical canker-like symptoms were observed on sweet orange (Citrus sinensis) groves on Mtsamboro islet and soon after on the main island of Mayotte, mostly on sweet oranges, but also on Tahiti limes (C. latifolia) and mandarins (C. reticulata). Eighty-one Xanthomonas-like strains were isolated using KC semi-selective medium (4) from disease samples collected from both commercial groves and nurseries on different Citrus species located all over the island. Sixteen Xanthomonas-like isolates were tentatively identified as X. citri pv. citri based on a specific PCR assay with 4/7 primers (3). All strains but the negative control, sterile water, produced an amplicon of the expected size similar to X. citri pv. citri strain IAPAR 306 used as positive control. Multilocus sequence analysis targeting six housekeeping genes (atpD, dnaK, efp, gltA, gyrB, and lepA) (1,2) fully identified three strains from Mayotte (LJ225-3, LJ228-1, and LJ229-11) as X. citri pv. citri (and not other xanthomonad pathovars pathogenic to citrus or host range-restricted pathotypes of pathovar citri), and more specifically as sequence type ST2 composed of pathotype A strains of X. citri pv. citri (2) (including all strains from the Southwest Indian Ocean region). Eight strains were inoculated by a detached leaf assay (2) to Mexican lime SRA 140 (C. aurantifolia), Tahiti lime SRA 58, sweet orange cv. Washington Navel, alemow SRA 779 (C. macrophylla), and tangor cv. Ortanique (C. reticulata × C. sinensis) and developed typical erumpent, callus-like tissue at wound sites for all Citrus species, fulfilling Koch's postulates. Xanthomonas-like yellow colonies were reisolated from symptoms produced by the eight strains inoculated on Mexican lime. Boiled bacterial suspensions were assayed by PCR with 4/7 primers (3) and produced the expected 468-bp amplicon in contrast with the negative control (sterile water). No lesions developed on the negative control consisting of inoculations by 10 mM tris buffer (pH 7.2). Citrus canker-free nurseries and grove sanitation should be implemented for decreasing the prevalence of Asiatic canker in this island territory. References: (1) N. F. Almeida et al. Phytopathology 100:208, 2010. (2) L. Bui Thi Ngoc et al. Int. J. Syst. Evol. Microbiol. 60:515, 2010. (3) J. S. Hartung et al. Phytopathology 86:95, 1996. (4) O. Pruvost et al. J. Appl. Microbiol. 99:803, 2005.

First Report of Sequence Type 1, Pathotype A Xanthomonas citri pv. citri from Lime and Lemon Fruit Originating from Bangladesh

Asiatic canker caused by Xanthomonas citri pv. citri, a quarantine pest in several countries (including the European Union), strongly impacts both national citrus markets in tropical and subtropical areas and international trade. This bacterium induces erumpent, callus-like lesions often with a water-soaked margin in a wide range of citrus species causing premature fruit drop and twig dieback. Long distance dispersal is mainly through infected propagative material and the role of fruit is still debated. During inspection of imported limes (C. aurantifolia) and lemons (C. limon) from Bangladesh from 2006 to 2009, canker-like infected fruits were intercepted by the UK plant health service. Typical corky lesions were surface sterilized and comminuted in 0.1% peptone solution. Suspensions were plated onto nutrient dextrose (ND) and yeast dextrose chalk (YDC) plates for bacterial isolation. After incubation for 3 to 7 days at 25°C, typical Xanthomonas-like yellow colonies were purified for identification. Identification of 18 isolates as Xanthomonas was carried out initially by fatty acid methyl ester (FAME) analysis. Identification at the species level (X. citri) was completed by sequencing of the gyrase B gene (4). PCR (3) was used to confirm the identity of these isolates using X. citri pv. citri CFBP 2525 as the positive control and distilled water as the negative control. The expected DNA fragment was only obtained from all of the bacterial isolates using primer pair 4/7 (3). Multilocus sequence analysis (MLSA) of four housekeeping genes (atpD, dnaK, efp, and gyrB) identified isolates from Bangladesh as two sequence types of X. citri pv. citri, ST1 (n = 5; GenBank Accession Nos. FJ376118, FJ376168, FJ376216, and FJ376251) and ST2 (n = 13; EU333904, EU333907, EU333910, and FJ376357), but not as any other xanthomonad pathogenic to citrus (2). Amplified fragment length polymorphism (AFLP) analysis of all X. citri pv. citri isolates from Bangladesh and additional reference isolates from pathotype A, A*, A^w and X. citri pv. aurantifolii (2) using Sac I/Msp I and four primer pairs (unlabelled MspI + 1 (A, C, T, or G) primers and 5'-labeled - SacI + C primer for the selective amplification step) confirmed identification as X. citri pv. citri. All five ST1 isolates grouped as a single cluster by AFLP, although not strongly supported by bootstrap analysis. Evolutionary genome divergences (EGD) computed from AFLP data ranged from 0.0000 to 0.0097 (median EGD 0.0055) suggested a relatively wide diversity within isolates originating from Bangladesh (median EGD from a worldwide pathotype A collection [n = 73] 0.0028) (2). When inoculated to Mexican lime SRA 140 and grapefruit cv. Duncan using a detached leaf assay (2), all the Bangladesh isolates produced typical extensive canker lesions on both species whereas the negative control (10 mM Tris buffer pH 7.2) did not, and Koch's postulates were fulfilled. To our knowledge, this is the first report of pathotype A assigned to ST1 by MLSA. All strains previously assigned to ST1 displayed a narrow host range (pathotype A*) (2). Our results further identify the Indian subcontinent as an area of relatively wide genetic diversity of X. citri pv. citri (1). References: (1) L. Bui Thi Ngoc et al. Appl. Environ. Microbiol. 75:1173, 2009. (2) L. Bui Thi Ngoc et al. Int. J. Syst. Evol. Microbiol. 60:515, 2010. (3) J. S. Hartung et al. Phytopathology 86:95, 1996. (4) N. Parkinson et al. Int. J. Syst. Evol. Microbiol. 57:2881, 2007.

Bronchogenic cyst of the tongue in an infant

Bronchogenic cyst of the tongue is rare. We report the case of a 17-month baby who has a lingual lesion. MRI shows a well-defined cystic lesion. Treatment consisted of a complete resection and histology found a pseudostratified respiratory type epithelium. Only 10 pediatric cases of bronchogenic cyst of the tongue have been reported in the literature. MRI is the imaging modality of choice and treatment is always surgical. The final diagnosis is made by histology.

Assessing the potential clinical utility of transplantations of neural and mesenchymal stem cells for treating neurodegenerative diseases

Treatments for neurodegenerative diseases have little impact on the long-term patient health. However, cellular transplants of neuroblasts derived from the aborted embryonic brain tissue in animal models of neurodegenerative disorders and in patients have demonstrated survival and functionality in the brain. However, ethical and functional problems due to the use of this fetal tissue stopped most of the clinical trials. Therefore, new cell sources were needed, and scientists focused on neural (NSCs) and mesenchymal stem cells (MSCs). When transplanted in the brain of animals with Parkinson's or Huntington's disease, NSCs and MSCs were able to induce partial functional recovery by promoting neuroprotection and immunomodulation. MSCs are more readily accessible than NSCs due to sources such as the bone marrow. However, MSCs are not capable of differentiating into neurons in vivo where NSCs are. Thus, transplantation of NSCs and MSCs is interesting for brain regenerative medicine. In this chapter, we detail the methods for NSCs and MSCs isolation as well as the transplantation procedures used to treat rodent models of neurodegenerative damage.

First Report in Mali of Xanthomonas citri pv. mangiferaeindicae Causing Mango Bacterial Canker on Mangifera indica

Bacterial canker (or black spot) of mango caused by Xanthomonas citri pv. mangiferaeindicae is an important disease in tropical and subtropical areas (1). X. citri pv. mangiferaeindicae can cause severe infection in a wide range of mango cultivars and induces raised, angular, black leaf lesions, sometimes with a chlorotic halo. Severe leaf infection may result in abscission. Fruit symptoms appear as small, water-soaked spots on the lenticels that later become star shaped, erumpent, and exude an infectious gum. Often, a "tear stain" infection pattern is observed on the fruit. Severe fruit infections cause premature drop. Twig cankers are potential sources of inoculum and weaken branch resistance to winds. Yield loss up to 85% has been reported at grove scale for susceptible cultivars (1). Suspected leaf lesions of bacterial canker were collected in July 2010 from mango trees in four, six, and three localities of the Koulikoro, Sikasso, and Bougouni provinces of Mali, respectively (i.e., the major mango-growing areas in this country). Nonpigmented Xanthomonas-like colonies were isolated on KC semiselective medium (3). Twenty-two strains from Mali were identified as X. citri pv. mangiferaeindicae based on IS1595-ligation-mediated PCR (4) and they produced fingerprints fully identical to that of strains isolated from Ghana and Burkina Faso. Five Malian strains (LH409, LH410, LH414, LH415-3, and LH418) were compared by multilocus sequence analysis (MLSA) to the type strain of X. citri and the pathotype strain of several X. citri pathovars, including pvs. anacardii and mangiferaeindicae. This assay targeted the atpD, dnaK, efp, and gyrB genes, as described previously (2). Nucleotide sequences were 100% identical to those of the pathotype strain of X. citri pv. mangiferaeindicae whatever the gene assayed, but differed from any other assayed X. citri pathovar. Leaves of mango cv. Maison Rouge from the youngest vegetative flush were infiltrated (10 inoculation sites per leaf for three replicate leaves on different plants per bacterial strain) with the same five strains from Mali. Bacterial suspensions (~1 × 10⁵ CFU/ml) were prepared in 10 mM Tris buffer (pH 7.2) from 16-h-old cultures on YPGA (7 g of yeast, 7 g of peptone, 7 g of glucose, and 18 g of agar/liter, pH 7.2). The negative control treatment consisted of three leaves infiltrated with sterile Tris buffer (10 sites per leaf). Plants were incubated in a growth chamber at 30 ± 1°C by day and 26 ± 1°C by night (12-h/12-h day/night cycle) at 80 ± 5% relative humidity. All leaves inoculated with the Malian strains showed typical symptoms of bacterial canker a week after inoculation. No lesions were recorded from the negative controls. One month after inoculation, mean X. citri pv. mangiferaeindicae population sizes ranging from 5 × 10⁶ to 1 × 10⁷ CFU/lesion were recovered from leaf lesions, typical of a compatible interaction (1). To our knowledge, this is the first report of the disease in Mali. Investigations from local growers suggest that the disease may have been present for some years in Mali but likely less than a decade. A high disease incidence and severity were observed, suggesting the suitability of environmental conditions in this region for the development of mango bacterial canker. References: (1) N. Ah-You et al. Phytopathology 97:1568, 2007. (2) L. Bui Thi Ngoc et al. Int. J. Syst. Evol. Microbiol. 60:515, 2010. (3) O. Pruvost et al. J. Appl. Microbiol. 99:803, 2005. (4) O. Pruvost et al. Phytopathology 101:887, 2011.

Personal health and consumer informatics

OBJECTIVES

To summarize current outstanding research in the field of Personal Health and Consumers Informatics.

METHODS

A selection of excellent research articles published in 2011 in the field of Personal Health Informatics and Consumer Informatics.

RESULTS AND CONCLUSIONS

This selection of articles shows that Personal Health Informatics is changing. Indeed, the different solutions tended to the doctors and their interaction, but also tended to the patient in order for him to be more active in his own medical healthcare. The consumer section highlights the development of the social network and the possible limitations.

First Report in Burkina Faso of Xanthomonas citri pv. mangiferaeindicae Causing Bacterial Canker on Mangifera indica

Bacterial canker of mango (or bacterial black spot) caused by Xanthomonas citri pv. mangiferaeindicae, is an economically important disease in tropical and subtropical areas (1). X. citri pv. mangiferaeindicae can cause severe infection on a wide range of mango cultivars and induces raised, angular, black leaf lesions, sometimes with a chlorotic halo. Fruit symptoms are black, star shaped, erumpent, and exude an infectious gum. A survey was conducted in Burkina Faso in May 2010 because budwood putatively associated with an outbreak of bacterial canker in Ghana had originated from Burkina Faso (3). Leaves and twigs with suspected bacterial canker lesions were collected from mango trees of the cvs. Amélie, Brooks, and Kent and from seedlings at five localities in Comoe and Houet provinces. Severe infections were observed on the sampled trees in Burkina Faso and leaf symptoms were typical of bacterial canker. Leaves were surface sterilized for 15 to 30 s with 70% ethanol, and nonpigmented, Xanthomonas-like bacterial colonies were isolated on KC semiselective agar medium (1). On the basis of an IS1595-ligation mediated PCR assay, 18 strains from Burkina Faso produced identical fingerprints and were identified as X. citri pv. mangiferaeindicae (4). The haplotype for strains from Burkina Faso was identical to that reported from Ghana (3). Three strains from Burkina Faso (LH127-2, LH130-1, and LH131-1) were compared by multilocus sequence analysis (MLSA) with the type strain of X. citri and the pathotype strain of several X. citri pathovars, including pvs. anacardii and mangiferaeindicae, targeting the atpD, dnaK, efp, and gyrB genes (2). Nucleotide sequences were 100% identical to those of the pathotype strain of X. citri pv. mangiferaeindicae, regardless of the gene assayed, but differed from any other X. citri pathovar assayed. Leaves of mango cv. Maison Rouge, taken from the youngest vegetative flush, were infiltrated (10 inoculation sites per leaf for three replicate leaves on different plants per bacterial strain) with the same three strains from Burkina Faso. Bacterial suspensions (approximately 1 × 10⁵ CFU/ml) were prepared in 10 mM Tris buffer (pH 7.2) from 16-h-old solid cultures on YPG agar (7 g of yeast, 7 g of peptone, 7 g of glucose, and 18 g of agar per liter, pH 7.2). The negative control treatment consisted of three leaves infiltrated with sterile Tris buffer (10 sites per leaf). Plants were incubated in a growth chamber at 30 ± 1°C by day and 26 ± 1°C by night (12-h/12-h day/night cycle) at 80 ± 5% relative humidity. Typical symptoms of bacterial canker were observed for all assayed strains 1 week after inoculation; no symptoms were observed from negative control leaves. One month after inoculation, mean X. citri pv. mangiferaeindicae populations ranging from 2 × 10⁷ to 8 × 10⁷ CFU/leaf lesion were recovered, which was typical of a compatible interaction (1). The origin of inoculum associated with the bacterial canker outbreak in Burkina Faso is unknown. This report documents severe infections in Burkina Faso (including premature fruit drop due to severe fruit infections) and confirms the presence of bacterial canker in western Africa. A more extensive survey for the disease should be conducted in this region. References: (1) N. Ah-You et al. Phytopathology 97:1568, 2007. (2) L. Bui Thi Ngoc et al. Int. J. Syst. Evol. Microbiol. 60:515, 2010. (3) O. Pruvost et al. Plant Dis. 95:774, 2011. (4) O. Pruvost et al. Phytopathology 101:887, 2011.

First Report of Xanthomonas citri pv. citri Pathotype A Causing Asiatic Citrus Canker on Grapefruit and Mexican Lime in Senegal

In February 2010, grapefruit (Citrus paradisi) and Mexican lime (C. aurantifolia) leaves with erumpent callus-like lesions were collected in Senegal in the Sebikotane area between Dakar and Thies. Similar symptoms have been observed by local farmers since 2008, and lesions were morphologically similar to those of citrus canker caused by Xanthomonas citri pv. citri (Asiatic canker) and X. citri pv. aurantifolii (South American canker). Lesions were primarily reported from grapefruit (cv. Shambar), which is the most frequent citrus species produced in this area, and Mexican lime, which is also commonly grown. Both species are very susceptible to X. citri pv. citri pathotype A, and Mexican lime is susceptible to X. citri pv. citri pathotype A* and X. citri pv. aurantifolii (4). Fifteen Xanthomonas-like strains were isolated from disease samples using KC semiselective medium (3). PCR with primer pair 4/7 (2) revealed that all the Senegalese strains and the X. citri pv. citri strain CFBP 2525 from New Zealand, used as a positive control, generated the expected DNA fragment, whereas no fragment was observed for negative controls (distilled water instead of the template). Insertion sequence ligation-mediated (IS-LM)-PCR analysis (1) of X. citri pv. citri strains from Senegal and reference strains of X. citri pv. citri pathotypes A and A* (1), with MspI and four primer pairs (unlabelled MspI primer and four 5'-labelled insertion sequence-specific primers targeting three IS elements), indicated that the strains from Senegal were related to X. citri pv. citri but not to pv. aurantifolii. They were closely related to X. citri pv. citri pathotype A strains, with a broad host range, present in the Indian subcontinent and Mali (C. Vernière, unpublished data). Multilocus sequence analysis of four partial housekeeping gene sequences (atpD, dnaK, efp, and gyrB) confirmed that four Senegalese strains were not related to X. citri pv. aurantifolii and showed a full sequence identity to X. citri pv. citri sequence type ST3 (2), fully consistent with IS-LM-PCR. Using a detached leaf assay (4), Duncan grapefruit, Pineapple sweet orange, and Mexican lime leaves inoculated with all strains from Senegal developed typical erumpent, callus-like tissue at wound sites 2 weeks after the inoculations. Xanthomonas-like colonies were reisolated and PCR amplification with the primer pair 4/7 produced the same 468-nt DNA fragment. This represents the fourth outbreak of citrus canker reported from Africa within the last 5 years, the other documented reports were from Ethiopia (2007) and Mali and Somalia (2008). High disease prevalence was observed in Senegal with incidence exceeding 90% in the orchards where lime and grapefruit were infected for 3 years, indicating the suitability of environmental conditions in this region for the development of Asiatic citrus canker. The origin of the inoculum associated with the reported canker outbreak in Senegal is currently unknown and the precise distribution of the pathogen needs to be thoroughly assessed. To our knowledge, this is the first documented report of the presence of Asiatic citrus canker in Senegal and this occurrence increases the threat to citriculture in West Africa. References: (1) L. Bui Thi Ngoc et al. FEMS Microbiol. Lett. 288:33, 2008. (2) L. Bui Thi Ngoc et al. Int. J. Syst. Evol. Microbiol. 60:515, 2010. (3) O. Pruvost et al. J. Appl. Microbiol. 99:803, 2005. (4) C. Vernière et al. Eur. J. Plant Pathol. 104:477, 1998.