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Introduction. Black Leaf Streak Disease (BLSD) is regarded as the most economically important threat that the banana industry has to face. Effectively, this foliar disease affects leaf photosynthesis but, above all, reduces the greenlife of fruits, that cannot be exported in cases of severe infestation. Main characteristics of Black Leaf Streak Disease. More than 20 Mycosphaerella species have been described on bananas. Leaf spot diseases of bananas are caused by some species of this complex, of which M. fijiensis (BLSD) and M. musicola (Sigatoka disease) are the most important. M. fijiensis is an invasive species that has totally replaced M. musicola in most banana-exporting countries, which was conducive to increasing difficulties in banana leaf spot control. BLSD causes increasing difficulties for control. Since all banana cultivars grown in the banana industry are highly susceptible to BLSD, the control of this disease relies on aerial applications of fungicides according to either systematic frameworks (mostly contact fungicides) or forecasting strategies (mostly systemic fungicides). In a banana-exporting country where M. fijiensis has been reported, BLSD control becomes increasingly more difficult. This evolution is essentially due to the rapid emergence of fungicide resistance, and is conducive to a significant increase in the cost of disease control but, above all, to increasing negative environmental effects. Challenges for the banana industry. Because of the rapid adaptation of M. fijiensis, the banana industry must be prepared for significant evolution. We propose various parameters that should be monitored at different levels (disease assessment parameters, evaluation of chemical control efficiency, global evaluation of BLSD economic incidence) to rationalize such evolution. The modelization of BLSD effects on bunch mass and greenlife should enable defining acceptable disease thresholds and optimizing bunch weight and harvest stage according to agronomic practices. On the other hand, fungicide use is conducive to significant environmental impact and must be limited. Forecasting strategies should be used wherever systemic fungicides are still efficient. Finally, the predominance of a unique type of susceptible cultivar is unsustainable and the recourse to resistant varieties in an integrated strategy is undoubtedly the future of BLSD control. Introduction. La Maladie des Raies Noires (MRN) est la plus grande menace à laquelle est confrontée l’industrie de la banane. En effet, cette maladie foliaire affecte la photosynthèse des bananiers mais, surtout, elle entraine une réduction du potentiel de conservation des fruits qui ne peuvent être exportés lorsque les bananiers sont sévèrement atteints. Principales caractéristiques de la MRN. Plus de 20 espèces du genre Mycosphaerella ont été décrites sur le bananier, mais les cercosporioses des bananiers sont principalement le fait de deux espèces M. fijiensis (MRN) et M. musicola (maladie de Sigatoka). M. fijiensis est une espèce invasive qui a totalement remplacé M. musicola dans la plupart des pays exportateurs de bananes, ce qui s’est toujours traduit par un contrôle plus difficile de la cercosporiose. Des difficultés de contrôle croissantes. Comme toutes les variétés de bananes cultivées dans l’industrie de la banane sont très sensibles aux cercosporioses, le contrôle de la MRN repose sur l’application aérienne de fongicides soit selon des programmes systématiques (fongicides de contact), soit sur avertissement (fongicides systémiques). Dans les pays exportateurs de bananes où M. fijiensis a été détecté, le contrôle de la MRN est devenu de plus en plus difficile. Cette évolution a principalement été le fait de l’apparition de souches résistantes aux fongicides et s’est traduite par une augmentation du coût de la lutte et surtout par un accroissement des impacts environnementaux. Des défis pour l’industrie bananière. Comme M. fijiensis a des capacités d’adaptation très rapides, une des conditions de survie de l’industrie bananière est de se préparer à d’importantes mutations. Nous proposons une batterie d’indicateurs à différents niveaux (parcelle, efficacité globale de la lutte, incidence économique globale) afin d’objectiver ces évolutions. La modélisation des effets de la MRN sur le poids des régimes et la durée de conservation des fruits devrait permettre de définir des niveaux de maladie acceptables mais aussi d’optimiser le poids des régimes et le stade de récolte en fonction des pratiques agronomiques. Afin de limiter l’emploi des fongicides qui ont un impact environnemental important, les stratégies d’avertissement doivent être employées partout où les fongicides systémiques sont encore efficaces. Enfin, la prédominance de cultivars sensibles n’est pas durable et le futur de cette industrie passe probablement par l’incorporation dans les systèmes de culture de variétés résistantes. Introducción. La enfermedad de las rayas negras (ERN) es la amenaza más grande a la cual se enfrenta la industria de la banana. Efectivamente, dicha enfermedad foliar afecta la fotosíntesis de los bananos, pero, sobre todo, conlleva una reducción del potencial de conservación de los frutos que no pueden exportarse cuando los bananos están severamente afectados. Principales características de la ERN. Se describieron en el banano más de 20 especies del género Mycosphaerella, pero las cercosporiosis de los bananos son principalmente el resultado de dos especies M. fijiensis (ERN) y M. musicola (enfermedad de Sigatoka). M. fijiensis es una especie invasiva que remplazó totalmente a M. musicola en la mayor parte de los países exportadores de bananos, lo que siempre se tradujo por un control más difícil de la cercosporiosis. Dificultades de control crecientes. Dado a que todas las variedades de bananos cultivados en la industria de la banana son muy sensibles a las cercosporiosis, el control de la ERN se basa en la aplicación aérea de fungicidas, tanto según programas sistemáticos (fungicidas de contacto), como por prevención (fungicidas sistemáticos). En los países exportadores de bananos donde se detectó M. fijiensis, el control de la ERN se ha vuelto cada vez más difícil. Dicha evolución se debe principalmente a la aparición de cepas resistentes a los fungicidas y se tradujo por un aumento del coste de la lucha, pero sobre todo por un incremento de los impactos medioambientales. Desafíos para la industria bananera. Dado a que M. fijiensis posee capacidades de adaptación muy rápida, una de las condiciones de supervivencia de la industria bananera es la preparación a importantes mutaciones. Proponemos un conjunto de indicadores de diferentes niveles (parcela, eficacia general de la lucha, incidencia económica general) con el fin de objetivar estas evoluciones. La modelización de los efectos de la ERN en el peso de los regímenes y la duración de conservación de los frutos debería permitir definir los niveles de enfermedad aceptables. Debería asimismo permitir optimizar el peso de los regímenes y el estado de cosecha en función de las prácticas agronómicas. De modo a limitar el uso de los fungicidas que tienen un impacto medioambiental importante, las estrategias de prevención deben emplearse ahí donde los fungicidas sistemáticos aún son eficaces. Por último, el predominio de cultivares sensibles no es duradero y el futuro de esta industria pasa probablemente por la incorporación de variedades resistentes en los sistemas de cultivo.

The study was aimed at the assessment whether foodstuffs contaminated with Bacillus cereus may concurrently be vectors of spreading resistance. The contamination of foodstuffs with B. cereus strains was found in 31 % of dairy and in 28 % of meat products tested. Only one product from skimmed milk was contaminated. High-fat milk products that were heat-treated during the technological process (87 samples), as well as heat-treated meat products (65 samples), were contaminated significantly frequently (63 % and 48 % of the samples, respectively, P0.01). Almost all B. cereus isolates displayed low susceptibility to ampicillin, cephalothin, and to oxacillin. Except for streptomycin (STR) resistance, resistance to other 8 antimicrobial agents occurred sporadically. The STR resistant isolates came particularly from spreading butter (8 samples, P0.05). It was established that the same samples were contaminated with two subpopulations of B. cereus with different STR resistances. The frequent occurrence of B. cereus in foodstuffs with either fat content and/or subject to heat treatment in processing makes these products risky. However, our study did not confirm that foodstuffs contaminated with B. cereus were concurrently vectors of transmissible resistance genes.

Eutypa lata and Phaeomoniella chlamydospora are important fungal grapevine trunk disease pathogens. Studies of their epidemiology and disease progression are hampered by the slow growth rates of the fungi and a lack of molecular tools. A protoplast-based transformation system was developed using hygromycin resistance as a positive selectable marker. The system was used to introduce a green fluorescent protein reporter gene that was expressed in the hyphae of both species. The reporter strains will be useful tools for further epidemiological studies. Furthermore, the transformation system will allow for genetic dissection of candidate pathogenicity or virulence genes by targeted replacement or disruption, in order to discern the rate of these genes in the disease process [Eutypa lata e Phaeomoniella chlamydospora sono funghi patogeni importanti agenti di malattie del tronco della vite. Gli studi sulla loro epidemiologia e sulla progressione della malattia sono ostacolati dalla lenta crescita di questi funghi e dalla mancanza di strumenti molecolari. E' stato sviluppato un sistema di trasformazione basato su protoplasti utilizzando la resistenza all'igromicina come marcatore positivo selezionabile. Il sistema è stato utilizzato per introdurre il gene reporter di una proteina fluorescente verde, che veniva espressa nelle ife di ambedue le specie. Questi ceppi reporter costituiranno strumenti utili per ulteriori studi di carattere epidemiologico. Inoltre, il sistema di trasformazione consentirà la discriminazione genetica della patogenicità candidata o dei geni della virulenza mediante sostituzione o rottura mirata, allo scopo di distinguere il livello di importanza di questi geni nel processo patologico.]

The objective of this study was to establish a repeatable, standardized laboratory procedure for monitoring the development of antimicrobial resistance in bacteria isolated from animals and food of animal origin in South Africa, with reagents prepared in-house. The emergence of resistance and the spread of resistant bacteria can be limited by implementing a veterinary antimicrobial drug policy, in which inter alia systematic monitoring and prudent use play essential roles. The bacteria included in this study represented three different categories, namely zoonotic bacteria (Salmonella), indicator bacteria (Escherichia coli, Enterococcus faecalis and Enterococcus faecium) and veterinary pathogens (Mannheimia haemolytica). Thirty isolates of each species were collected with the aim of standardizing the laboratory methodology for a future national veterinary surveillance and monitoring programme. Susceptibility to ten selected antimicrobial drugs was determined by means of minimum inhibitory concentrations (MICs) using the microdilution method. The method according to the National Committee for Clinical Laboratory Standards was used as the standard. Multi-well plates containing varying dilutions of antimicrobial drugs and prepared in-house for MIC determinations, yielded repeatable results. Storage of plates for 2 months at -70 oC did not influence results meaningfully. Within this limited sample of bacteria, MIC results did not indicate meaningful resistance against any of the ten selected antimicrobial drugs. The findings of the study will be used to establish a national veterinary antimicrobial resistance surveillance and monitoring programme in South Africa. To allow for international comparison of data, harmonisation of the surveillance and monitoring programme in accordance with global trends is encouraged. Ideally it should be combined with a programme monitoring the quantities of antimicrobial drugs used. The aim is to contribute to slowing down the emergence of resistance and the problems associated with this phenomenon by means of the rational use of antimicrobial drugs.

Phomopsis viticola (Sacc.) Sacc. is the phytopathogenic fungus causing a severe disease of grapevine known as Phomopsis cane and leaf spot. Protoplasts from mycelium of P. viticola were successfully transformed with plasmids carrying either the bacterial hph gene, conferring resistance to hygromycin B (pAN7-1, pOHT, pOHT-AMA1), or the Bml sup (r) gene from Neurospora crassa, causing resistance to benzimidazole fungicides (pBT6). Up to more than 300 transformants per microng of plasmid DNA were obtained with the hph marker gene. The highest effectiveness was obtained with pOHT, whereas pBT6 yielded around 25 transformants per microng of plasmid DNA. Southern blot analysis showed the occurrence of multiple integration events in the fungal genome of all tested plasmids. Experiments of co-transformation with pOHT and pBT6 were successful and about 70% of transformants were resistant to both hygromycin B and benomyl. The Instant Gene Bank technique and mutagenesis through Restriction Enzyme Mediated Integration (REMI) were attempted. As reported for other phytopathogenic fungi, the REMI technique proved to be a powerful method for obtaining mutant strains with variation in phenotypic traits [Phomopsis viticola (Sacc.) Sacc. e' il fungo fitopatogeno agente di una malattia grave della vite denominata escoriosi. Protoplasmi derivanti dal micelio di P. viticola sono stati trasformati con plasmidi portanti sia il gene batterico hph, che conferisce la resistenza all'igromicina B (pAN7-1, pOHT, pOHT-AMA1), sia il gene Bml sup (r) di Neurospora crassa, che causa la resistenza ai fungicidi benzimidazolici (pBT6). Con il gene marcatore hph sono stati ottenuti fino a piu' di 300 trasformanti per microng di DNA plasmidiale. La maggiore efficienza e' stata ottenuta con pOHT, mentre pBT6 produceva circa 25 trasformanti per microng di DNA plasmidiale. L'analisi Southern blot ha evidenziato il verificarsi di eventi di integrazione multipla di tutti i plasmidi sperimentati nel genoma del fungo. Esperimenti di co-trasformazione con pOHT e pBT6 hanno avuto successo e circa il 70% dei trasformanti e' risultato resistente sia all'igromicina B, sia al benomyl. Sono state provate la tecnica dell'Instant Gene Bank e la mutagenesi attraverso l'integrazione mediata da enzimi di restrizione (REMI). Come riportato per altri funghi fitopatogeni, la tecnica REMI si e' dimostrata un metodo efficace per ottenere ceppi mutanti con variazione dei caratteri fenotipici]

Nuclear factor erythroid 2-related factor 2 (Nrf2) is a key transcriptional regulator for the protection of cells against oxidative and xenobiotic stresses. Recent studies have demonstrated that high constitutive expression of Nrf2 is observed in many types of cancer cells showing resistance to anti-cancer drugs, suggesting that the suppression of overexpressed Nrf2 could be an attractive therapeutic strategy to overcome cancer drug resistance. In the present study, we aimed to find small molecule compounds that enhance the sensitivity of tumor cells to cisplatin induced cytotoxicity by suppressing Nrf2-mediated defense mechanism. A549 lung cancer cells were shown to be more resistant to the anti-cancer drug cisplatin than HEK293 cells, with higher Nrf2 signaling activity; constitutively high amounts of Nrf2-downstream target proteins were observed in A549 cells. Among the three chalcone derivatives 4-methoxy-chalcone (4-MC), hesperidin methylchalcone, and neohesperidin dihydrochalcone, 4-MC was found to suppress transcriptional activity of Nrf2 in A549 cells but to activate it in HEK293 cells. 4-MC was also shown to down-regulate expression of Nrf2 and the downstream phase II detoxifying enzyme NQO1 in A549 cells. The PI3K/Akt pathway was found to be involved in the 4- MC-induced inhibition of Nrf2/ARE activity in A549 cells. This inhibition of Nrf2 signaling results in the accelerated generation of reactive oxygen species and exacerbation of cytotoxicity in cisplatin-treated A549 cells. Taken together, these results suggest that the small molecule compound 4-MC could be used to enhance the sensitivity of tumor cells to the therapeutic effect of cisplatin through the regulation of Nrf2/ARE signaling.

This review examines potential impacts of transgenic cultivars on insect population dynamics and evolution. Experience with classically bred, insecticidal cultivars has demonstrated that a solid understanding of both the target insect's ecology and the cultivar's performance under varied field conditions will be essential for predicting area-wide effects of transgenic cultivars on pest and natural enemy dynamics. This experience has also demonstrated the evolutionary capacity of pests for adaptive response to insecticidal traits in crops. Biochemical and genetic studies of insect adaptation to the Bacillus thuringiensis (Bt) toxins expressed by currently marketed transgenic cultivars indicate a high risk for rapid adaptation if these cultivars are misused. Theoretical and practical issues involved in implementing strategies to delay pest adaptation to insecticidal cultivars are reviewed. Emphasis is placed on examining the \"high dose\"/refuge strategy that has become the goal of industry and regulatory authorities.

A total of 669 individual cow milk samples originating from asymptomatic cows from 16 dairy farms were examined for the presence of microorganisms with the potential to cause mastitis. Coagulase-negative staphylococci clearly predominated (53.5% positive samples) followed by streptococci and enterococci (both occurring in 16.1% samples). Among streptococci, so-called mastitis streptococci (S. uberis, S. dysgalactiae and S. agalactiae) prevailed (11.7% positive samples). Enterobacteriaceae were found in 10.0% samples, most of which (6.6% samples) were positive for Escherichia coli. Yeasts (mainly Candida spp.) were found in 8.2% samples. One of the major mastitis pathogens, Staphylococcus aureus subsp. aureus, was isolated from 9.0% of samples. S. aureus isolates were further characterised in terms of their capability to form biofilm, antimicrobial susceptibility and clonality (PFGE). All S. aureus isolates were capable of biofilm formation and were generally susceptible to the majority of tested antibiotics. The exception was ampicillin, resistance to which was observed in 27.7% isolates. Therefore, the relatively frequent occurrence of S. aureus could be attributed to persistent intramammary infections due to biofilm formation rather than low efficacy of particular antibiotics. PFGE analysis revealed clonal spread of certain S. aureus isolates within and between farms indicating that certain lineages of S. aureus mastitis strains are particularly successful.

Insecticide research led to the first \"complete\" victories in combatting pests almost 50 years ago with the chlorinated hydrocarbons followed quickly by the organophosphates, methylcarbamates, and pyrethroids-all neuroactive chemicals. This Golden Age of Discovery was the source of most of our current insecticides. The challenge then became health and the environment, a Golden Age met with selective and degradable compounds. Next the focus shifted to resistance, novel biochemical targets, and new chemical approaches for pest control. The current Golden Age of Genetic Engineering has curtailed, but is unlikely to eliminate, chemical use on major crops. Insecticide research, having passed through several Golden Ages, is now in a renaissance of integrating chemicals and biologicals for sustainable pest control with human safety.