Characterization of New Races of Xanthomonas oryzae pv. oryzae in Mali Informs Resistance Gene Deployment.

Bacterial leaf blight caused by Xanthomonas oryzae pv. oryzae represents a severe threat to rice cultivation in Mali. Characterizing the pathotypic diversity of bacterial populations is key to the management of pathogen-resistant varieties. Forty-one X. oryzae pv. oryzae isolates were collected between 2010 and 2013 in the major rice growing regions in Mali. All isolates were virulent on the susceptible rice variety Azucena; evaluation of the isolates on 12 near isogenic rice lines, each carrying a single resistance gene, identified six new races (A4 to A9) and confirmed race A3 that was previously reported in Mali. Races A5 and A6, isolated in Office du Niger and Sélingué, were the most prevalent races in Mali. Race A9 was the most virulent, circumventing all of the resistance genes tested. Xa3 controlled six of seven races (i.e., 89% of the isolates tested). The expansion of race A9 represents a major risk to rice cultivation and highlights the urgent need to identify a local source of resistance. We selected 14 isolates of X. oryzae pv. oryzae representative of the most prevalent races to evaluate 29 rice varieties grown by farmers in Mali. Six isolates showed a high level of resistance to X. oryzae pv. oryzae and were then screened with a larger collection of isolates. Based on the interactions among the six varieties and the X. oryzae pv. oryzae isolates, we characterized eight different pathotypes (P1 to P8). Two rice varieties, SK20-28 and Gigante, effectively controlled all of the isolates tested. The low association observed among races and pathotypes of X. oryzae pv. oryzae suggests that the resistance observed in the local rice varieties does not simply rely on single known Xa genes. X. oryzae pv. oryzae is pathogenically and geographically diverse. Both the races of X. oryzae pv. oryzae characterized in this study and the identification of sources of resistance in local rice varieties provide useful information to inform the design of effective breeding programs for resistance to bacterial leaf blight in Mali.

Supervised short-stretch compression therapy in mixed leg ulcers.

OBJECTIVES: This study was conducted to determine hemodynamic and clinical tolerance under short-stretch compression therapy in elderly patients suffering from mixed-etiology leg ulcers. DESIGN: Transversal observational study conducted in 25 hospitalized patients with a moderate peripheral arterial occlusive disease defined as an ankle-brachial pressure index>0.5, an ankle pressure of>70mmHg and a toe cuff pressure (TP)>50mmHg. MATERIAL AND METHODS: Short-stretch bandages were applied daily with pressures from 20 to 30mmHg. Ankle-brachial pressure, great toe laser Doppler flowmetry (LDF) and transcutaneous oxygen pressure (TcPO2) on dorsum of the foot were measured at baseline and after its removal at 24hours. Great toe LDF was also measured at 10minutes after bandage application. Compression pressure (CP) was measured with a sub-bandage device at baseline, at 10minutes and before bandage removal at 24hours. Clinical tolerance was evaluated taking into account the patient's pain and skin tolerance. RESULTS: Mean age of patients was 80±15 years. Median duration of ulcers was 18 months. Hypertension was highly prevalent. One third of patients had diabetes. Toe pressure index and TcPO2 values did not significantly change under compression therapy (P=0.51 and P=0.09, respectively) whereas CP decreased significantly during 24hours. The loss of CP was significant 10minutes after bandage application (P<0.001). Nearly all ulcers were painful prior to placement of compression therapy and required level 1 analgesics. One patient required level 2 analgesic for pain relief. No increase in pain and no ischemic skin damage occurred under compression therapy. CONCLUSIONS: In elderly patients with mixed leg ulcers and with an absolute TP>50mmHg, short-stretch compression of up to 30mmHg does not adversely affect arterial flow and appears clinically well tolerated. Such bandages with appropriate levels of compression may aid ulcer healing by treating the venous part of the disease.

[Amoebic liver abscess in general surgery at the Gabriel Touré teaching hospital, Bamako, Mali]. / Abces amibien du foie en chirurgie generale du CHU gabriel toure, Bamako, Mali.

The objectives were to determine the frequency, and to describe the clinical and therapeutic aspects of amoebic liver abscess. This was a retrospective study in the general surgery department of the Gabriel Touré teaching hospital from 1 January 2004 to December 2008. Included in this study, were all patients hospitalized and treated for amoebic liver abscess. We collected 53 cases a frequency of 1.3%. This was 45 men (84.9%) and 8 women (15.1%). The sex ratio was 5.6. The average age was 39.5 years. The average consultation time was 3 weeks. The signs observed were fever 96.2% (51 cases), the hepatalgia 94.3% (50 case), hepatomegaly 90.6% (48 cases) and anorexia 88.7% (47 cases). Collections of objectified abscess in abdominal ultrasound were located in the right lobe in 79.2% (42 cases), unique in 92.5% (49 cases) and 100 mm in diameter on average. Pulmonary radiography found an elevation of the right diaphragmatic dome 66.7% (14 cases). Amoebic serology was performed in 60.4% of cases, was negative in 2 cases (6.2%). Medical treatment alone was effective in the majority of cases - 62.7% (32 cases), an ultrasound-guided paracentesis associated with medical treatment was required in 31.4% (16 cases). Surgical methods were very rarely recommended 5.9 % (3 cases). The average amount of pus was 637.6ml. Average duration of treatment was 11 days. We recorded three deaths, including one due to a sepsis on peritonitis from ruptured liver abscess and 2 cases due to HIV. CONCLUSION: The amoebic liver abscess is uncommon in our service. Negative serology does not exclude the diagnosis. Medical treatment is usually curative in the absence of complications.

Les objectifs étaient de déterminer la fréquence, de décrire les aspects cliniques et thérapeutiques de l'abcès amibien du foie.Il s'agissait d'une étude rétrospective réalisée dans le service de chirurgie générale du CHU Gabriel Touré du 1er Janvier 2004 au Décembre 2008. Ont été inclus dans cette étude tous les patients hospitalisés et traités pour abcès amibien du foie. Nous avons colligé 53 dossiers soit une fréquence de 1,3%. Il s'agissait de 45hommes (84,9%) et 8femmes (15,1%). Le sex-ratio a été de 5.6 et la moyenne d'âge 39.5 ans. Le délai moyen de consultation a été de 3 semaines. Les signes observés ont été la fièvre 96.2% (51cas), l'hépatalgie 94.3%(50cas), l'hépatomégalie 90.6% (48cas) et l'anorexie 88.7%(47cas). Les collections d'abcès objectivées à l'échographie abdominale étaient localisées dans le lobe droit dans 79.2%(42cas), uniques dans 92.5%(49cas) et de 100 mm de diamètre en moyenne. La radiographie pulmonaire de face a retrouvé une surélévation de la coupole diaphragmatique droite 66,7% (14cas). La sérologie amibienne effectuée dans 60.4% des cas, a été négative dans 2 cas (6.2%). Le traitement médical seul a été efficace dans la majorité des 62.7% (32cas), une ponction évacuatrice échoguidée associé au traitement médical a été nécessaire dans 31,4% (16 cas). Les méthodes chirurgicales ont été très peu recommandées 5,9%(3cas). La quantité moyenne de pus a été de 637.6ml. La durée Moyenne de traitement a été de 11 jours. Nous avons enregistré 3 décès dont l'un suite à une septicémie sur péritonite par rupture d'abcès du foie et les 2cas sur terrain VIH. CONCLUSION: L'abcès amibien du foie est peu fréquent dans notre service. La négativité de la sérologie n'exclut pas le diagnostic. Le traitement médical est habituellement curatif en l'absence de complication.