Antimicrobial Resistance,Virulence Factor-Encoding Genes,and Biofilm-Forming Ability of Community-Associated Uropathogenic Escherichia Coli in Western Saudi Arabia

To explore the prevalence of multidrug-resistant community-associated uropathogenic Escherichia coli (UPEC) and their virulence factors in Western Saudi Arabia. A total of 1,000 urine samples were examined for the presence of E. coli by selective plating on MacConkey, CLED, and sheep blood agar. Antimicrobial susceptibility patterns were determined using Vitek^® 2 Compact (MIC) and the disc diffusion method with Mueller-Hinton agar. Genes encoding virulence factors (kpsMTII, traT, sat, csgA, vat, and iutA) were detected by PCR. The overall prevalence of UTI-associated E. coli was low, and a higher prevalence was detected in samples of female origin. Many of the isolates exhibited resistance to norfloxacin, and 60% of the isolates showed resistance to ampicillin. No resistance to imipenem, meropenem, or ertapenem was detected. In general, half of the isolates showed multiple resistance patterns. UPEC exhibited a weak ability to form biofilms, where no correlation was observed between multidrug resistance and biofilm-forming ability. All uropathogenic E. coli isolates carried the kpsMTII, iutA, traT, and csgA genes, whereas the low number of the isolates harbored the sat and vat genes. The diversity of virulence factors harbored by community-associated UPEC may render them more virulent and further explain the recurrence/relapse cases among community-associated UITs. To the best of our knowledge, this study constitutes the first exploration of virulence, biofilm-forming ability, and its association with multidrug resistance among UPEC isolates in Saudi Arabia. Further investigations are needed to elucidate the epidemiology of community-associated UPEC in Saudi Arabia. Open in a separate window     

Vitamin C-Gehalt Eisen-Bzw. Magnesium-Frei Gezogener Pflanzen

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Comprehensive Suppression of All Apoptosis-Induced Proliferation Pathways as a Proposed Approach to Colorectal Cancer Prevention and Therapy

Mutations in the WNT/beta-catenin pathway are present in the majority of all sporadic colorectal cancers (CRCs), and histone deacetylase inhibitors induce apoptosis in CRC cells with such mutations. This apoptosis is counteracted by (1) the signaling heterogeneity of CRC cell populations, and (2) the survival pathways induced by mitogens secreted from apoptotic cells. The phenomena of signaling heterogeneity and apoptosis-induced survival constitute the immediate mechanisms of resistance to histone deacetylase inhibitors, and probably other chemotherapeutic agents. We explored the strategy of augmenting CRC cell death by inhibiting all survival pathways induced by the pro-apoptotic agent LBH589, a histone deacetylase inhibitor: AKT, JAK/STAT, and ERK signaling. The apoptosis-enhancing ability of a cocktail of synthetic inhibitors of proliferation was compared to the effects of the natural product propolis. We utilized colorectal adenoma, drug-sensitive and drug-resistant colorectal carcinoma cells to evaluate the apoptotic potential of the combination treatments. The results suggest that an effective approach to CRC combination therapy is to combine apoptosis-inducing drugs (e.g., histone deacetylase inhibitors, such as LBH589) with agents that suppress all compensatory survival pathways induced during apoptosis (such as the cocktail of inhibitors of apoptosis-associated proliferation). The same paradigm can be applied to a CRC prevention approach, as the apoptotic effect of butyrate, a diet-derived histone deacetylase inhibitor, is augmented by other dietary agents that modulate survival pathways (e.g., propolis and coffee extract). Thus, dietary supplements composed by fermentable fiber, propolis, and coffee extract may effectively counteract neoplastic growth in the colon.     

Seasonal rhythm of physiological indexes,liver protein level,and biotransformation biomarkers in Zosterisessor ophiocephalus and Gobius niger from a low contaminated lagoon (Ghar El Melh lagoon,Tunisia)

This study assessed seasonal variation of total liver proteins level (LPLs) and biotransformation biomarkers in two fish species, G. niger and Z. ophiocephalus, during a one year-survey in the low contaminated Ghar-El-Melh lagoon, Tunisia. Analyzed biomarkers were compared with physiological indexes such as the condition index, hepato-somatic index, and gonado-somatic index and environmental parameters. A significant annual rhythms of glutathione-S-transferase and ethoxyresorufin-O-deethylase activities were validated by cosinor. The highest peak (acrophase) of activities occurred in summer likely related to the elevated seawater temperature. Midline Estimating Statistic of Rhythm and amplitudes were higher in Z. ophiocephalus than in G. niger. The results showed, as well, an acrophase of (LPLs) in spring coinciding with reproductive period in Z. ophiocephalus and beginning of reproductive period in G. niger. This study established a baseline for the selected enzymatic activities in gobies, which required information for a correct interpretation of biomarker responses in environmental monitoring.     

Priming-induced changes in germination,morpho-physiological and leaf biochemical responses of fenugreek (Trigonella foenum-graecum) under salt stress

Abstract

Seed priming is a simple biotechnological tool which is potentially able to promote seed germination and invigoration as well as seedlings establishment and stress tolerance. In this study, the effects of seed pre-treatment with water (hydro-priming), 100 (HP-NaCl₁₀₀) and 200?mM (HP-NaCl₂₀₀) NaCl (halo-priming) for 6?h on some physiological and biochemical parameters of fenugreek was investigated under saline conditions (100?mM NaCl). For the three priming treatments, no significant changes in the final germination percentage were observed. However, a decrease in seed germination time was observed in hydro- and halo-primed (HP-NaCl₂₀₀) seeds. Salt stress (100?mM NaCl) reduced growth (shoot and root dry weight), pigment content, disturbed the ionic balance and enhanced malondialdehyde content. Salinity-induced changes in lipid metabolism towards synthesis/accumulation of saturated and monounsaturated fatty acids were observed in stressed plants. Seed priming ameliorated the negative effects of NaCl, ensuring significant amelioration on growth, pigment content, increased the activity of catalase and glutathione peroxidase and enhanced the synthesis of very long chain n-alkanes. Taken together, these data provide compelling evidence that priming is an effective alternative that can be used to promote germination and improves establishment and acclimation of fenugreek seedlings under saline conditions.     

Subject-specific body segment parameters' estimation using biplanar X-rays: a feasibility study

In order to improve the reliability of children's models, the aim of this study was to determine the subject-specific masses and 3D locations of the centres of mass (CoM) of body segments using biplanar X-rays. Previous methods, validated on upper leg segments, were applied to the whole body. Six children and six adults were studied. The low-dose X-ray system EOS(?) was used to simultaneously get head-to-foot biplanar X-rays in the upright position. Specific methods were used to get 3D reconstructions of bones and body shape. The densities from the literature were used to define the masses. To assess the accuracy of the reconstructions, a force plate was used to compare the mass and the projection of the CoM. A mean distance of 4.5?mm between the measured and the calculated projections of the CoM was found. The mean error between the estimated and the actual body mass was 2.6%. Such a method will be useful in obtaining the body segment parameters in children, hard to obtain using direct measurement techniques.     

Sperm chromatin acquires an activity that induces microtubule assembly during residence in the cytoplasm of metaphase oocytes of the mouse

Evidence from several cell types indicates that chromatin can induce microtubule assembly in its vicinity. To determine whether this activity is present in sperm chromatin, whose biochemical composition differs from somatic chromatin, mouse oocytes that were undergoing meiotic maturation were inseminated. Maturing oocytes are not activated by sperm penetration but remain arrested at metaphase. The sperm chromatin within the oocyte cytoplasm initially became dispersed and later, under the influence of oocyte cytoplasmic factors, recondensed into a small mass of individual chromosomes. When inseminated oocytes were processed for immunofluorescence using an anti--tubulin antibody, microtubules were never associated with dispersed sperm chromatin, although the chromosomes of the oocyte were arranged on a spindle. In contrast, microtubules were associated with the majority of sperm nuclei that had become recondensed, and were frequently arranged into a spindle-like structure. When oocytes had been penetrated by more than three sperm, most sperm nuclei remained at the dispersed chromatin stage and these were never associated with microtubules. Exposure of polyspermic oocytes to taxol, which promotes microtubule assembly, failed to induce microtubule assembly around dispersed sperm chromatin. Exposure of monospermic oocytes to nocodazole, which inhibits tubulin polymerization, prevented resolution of the recondensed sperm chromatin into individual chromosomes. These results suggest that sperm chromatin lacks an activity that can induce local microtubule assembly, and that it acquires this activity once modified by oocyte cytoplasmic factors.