Search results for "RESISTANCE"
showing 10 items of 3641 documents
Occurrence of Drug-Resistant Bacteria in Two European Eel Farms
2005
ABSTRACT The occurrence of strains that are resistant to oxolinic acid, oxytetracycline, sulfamethoxazole-trimethoprim, and nitrofurantoin among heterotrophic bacteria, including human and fish pathogens, in two freshwater eel farms was investigated. High levels of individual- and multiple-drug-resistant bacteria were detected, although sampling events were not correlated with clinical outbreaks and drug therapy.
Esterase isoenzymes and insecticide resistance in Frankliniella occidentalis populations from the south-east region of Spain.
2008
BACKGROUND:Frankliniella occidentalis (Pergande) is among the most important crop pests in the south-east region of Spain; its increasing resistance to insecticides constitutes a serious problem, and understanding the mechanisms involved is therefore of great interest. To this end, F. occidentalis populations, collected from the field at different locations in south-east Spain, were studied in terms of total esterase activity and esterase isoenzyme pattern. RESULTS: Individual thrips extracts were analysed by native polyacrylamide gel electrophoresis (PAGE) and stained for esterase activity with the model substrate α-naphthyl acetate. Significant correlations were found between resistance t…
Extended-Spectrum ß-Lactamase, AmpC-Producing, and Fluoroquinolone-Resistant Escherichia coli in Retail Broiler Chicken Meat, Italy.
2015
Background: Globally, antimicrobial drug-resistant Escherichia coli is among the most common etiological agents of invasive disease in humans. In Europe, increasing proportions of infections due to third-generation cephalosporins and/or fluoroquinolone-resistant extraintestinal pathogenic E. coli (ExPEC) strains are reported. E. coli from poultry are those more closely linked to human E. coli, but lack of reliable data makes it difficult to assess the attributable risk of different food sources. In the present study, our objective was to investigate the antimicrobial resistance profile, phylogenetic background, and virulence factors of E. coli isolates from broiler chicken meat sold at reta…
The effect of metals on condition and pathologies of European eel (Anguilla anguilla): in situ and laboratory experiments.
2011
Forty-nine wild eels (Anguilla anguilla) caught in the Albufera Lake (Spain), measuring 24.0-75.0 cm in length and 25.0-637.7 g in weight, were examined for metals (Cd, Co, Cr, Cu, Fe, Hg, Mn, Pb, Se and Zn), condition (CI and HSI indices), as well as for diseases (Anguillicola infestation; bacterial infections). Total metal load significantly increased in eel liver tissue parallel to total length and body weight (log), while silvering females (W(B) > 200 g; L ≥ 500 mm) exhibited the highest amounts of Co, Cu, Hg, Se and Zn. Diverse effects may be expected in these big eels due to long-term metal exposure. In fact, IMBI (individual mean (multi-metal) bioaccumulation index) and copper load (…
European Sea Bass (Dicentrarchus labrax) immune status and disease resistance are impaired by arginine dietary supplementation
2015
Infectious diseases and fish feeds management are probably the major expenses in the aquaculture business. Hence, it is a priority to define sustainable strategies which simultaneously avoid therapeutic procedures and reinforce fish immunity. Currently, one preferred approach is the use of immunostimulants which can be supplemented to the fish diets. Arginine is a versatile amino acid with important mechanisms closely related to the immune response. Aiming at finding out how arginine affects the innate immune status or improve disease resistance of European seabass (Dicentrarchus labrax) against vibriosis, fish were fed two arginine-supplemented diets (1% and 2% arginine supplementation). A…
Molecular docking and pharmacogenomics of vinca alkaloids and their monomeric precursors, vindoline and catharanthine.
2011
International audience; Vinblastine and vincristine are dimeric indole alkaloids derived from (formerly: ). Their monomeric precursor molecules are vindoline and catharanthine. While vinblastine and vincristine are well-known mitotic spindle poisons, not much is known about vindoline and catharanthine. Vindoline and catharanthine showed weak cytotoxicity, while vinblastine, vincristine, and the semisynthetic vindesine and vinorelbine revealed high cytotoxicity towards cancer cells. This may reflect a general biological principle of poisonous plants. Highly toxic compounds are not only active towards predators, but also towards plant tissues. Hence, plants need mechanisms to protect themselv…
Effects of Tumor Necrosis Factor-Alpha on Growth and Doxorubicin Sensitivity of Multidrug Resistant Tumor Cell Lines
1993
Biological agents might offer various therapeutic opportunities in the treatment of cancer, including a direct and/or host- mediated antiproliferative effect as well as the possibility to favourably modulate tumor sensitivity to antineoplastic drugs (Alexander et al., 1987; Kikuchi et al., 1992; Wadler and Schwartz, 1990). However, information on their activity on chemoresistant tumors is still scanty (Billi et al., 1991; Bonavida et al., 1989; D’Alessandro, 1993; Fruehauf et al., 1991; Liddill et al., 1988; Mihich and Ehrke, 1991). Here we have focused on tumor necrosis-alpha (TNF-α) and studied its in vitro effects on the growth of two tumor cell lines, the mouse B16 melanoma and Friend e…
The evolution of collective infectious units in viruses
2019
Viruses frequently spread among cells or hosts in groups, with multiple viral genomes inside the same infectious unit. These collective infectious units can consist of multiple viral genomes inside the same virion, or multiple virions inside a larger structure such as a vesicle. Collective infectious units deliver multiple viral genomes to the same cell simultaneously, which can have important implications for viral pathogenesis, antiviral resistance, and social evolution. However, little is known about why some viruses transmit in collective infectious units, whereas others do not. We used a simple evolutionary approach to model the potential costs and benefits of transmitting in a collect…
Sortase A: An ideal target for anti-virulence drug development
2014
Sortase A is a membrane enzyme responsible for the anchoring of surface-exposed proteins to the cell wall envelope of Gram-positive bacteria. As a well-studied member of the sortase subfamily catalysing the cell wall anchoring of important virulence factors to the surface of staphylococci, enterococci and streptococci, sortase A plays a critical role in Gram-positive bacterial pathogenesis. It is thus considered a promising target for the development of new anti-infective drugs that aim to interfere with important Gram-positive virulence mechanisms, such as adhesion to host tissues, evasion of host defences, and bio fi lm formation. The additional properties of sortase A as an enzyme that i…
Virus-Host Coevolution as a Tool for Controlling Bacterial Resistance to Phage Therapy
2019
Bacterial resistance to antibiotics is a global public health concern. New treatments are needed to combat resistant strains, among which phage therapy is a promising option. Probably the main advantages of phage therapy are its high specificity as well as rapid viral adaptability, which in principle allows using phage evolution to overcome resistance. Here, we have performed serial coevolution passages between Escherichia coli and its phage T7 to investigate the ability of coevolved phages to reduce the emergence of resistances. We find that the initial bacterial population is less likely to undergo resistance when challenged with experimentally coevolved phages than when challenged with t…