Detection of macrolide and disinfectant resistance genes in clinical Staphylococcus aureus and coagulase-negative staphylococci

<p>Abstract</p> <p>Background</p> <p><it>Staphylococcus aureus </it>and Coagulase-negative staphylococci (CoNS) are a major source of infections associated with indwelling medical devices. Many antiseptic agents are used in hygienic handwash to prevent nosocomial infections by Staphylococci. Our aim was to determine the antibiotic susceptibility and resistance to quaternary ammonium compound of 46 <it>S. aureus </it>strains and 71 CoNS.</p> <p>Methods</p> <p><it>S. aureus </it>(n = 46) isolated from auricular infection and CoNS (n = 71), 22 of the strains isolated from dialysis fluids and 49 of the strains isolated from needles cultures were investigated. Erythromycin resistance genes (<it>erm</it>A, <it>erm</it>B, <it>erm</it>C, <it>msr</it>A and <it>mef</it>) were analysed by multiplex PCR and disinfectant-resistant genes (<it>qac</it>A, <it>qac</it>B, and <it>qac</it>C) were studied by PCR-RFLP.</p> <p>Results</p> <p>The frequency of erythromycin resistance genes in <it>S. aureus </it>was: <it>erm</it>A+ 7.7%, <it>erm</it>B+ 13.7%, <it>erm</it>C+ 6% and <it>msr</it>A+ 10.2%. In addition, the number of positive isolates in CoNS was respectively <it>erm</it>A+ (9.4%), <it>erm</it>B+ (11.1%), <it>erm</it>C+ (27.4%), and <it>msr</it>A+ (41%). The MIC analyses revealed that 88 isolates (74%) were resistant to quaternary ammonium compound-based disinfectant benzalkonium chloride (BC). 56% of the BC-resistant staphylococcus isolates have at least one of the three resistant disinfectants genes (<it>qac</it>A, <it>qac</it>B and <it>qac</it>C). Nine strains (7.7%) among the CoNS species and two <it>S. aureus </it>strains (2%) harboured the three-<it>qac </it>genes. In addition, the <it>qac</it>C were detected in 41 strains.</p> <p>Conclusions</p> <p>Multi-resistant strains towards macrolide and disinfectant were recorded. The investigation of antibiotics and antiseptic-resistant CoNS may provide crucial information on the control of nosocomial infections.</p

Obesity resistance and increased energy expenditure by white adipose tissue browning in Oga +/- mice.

Aims/hypothesis O-GlcNAcylation plays a role as a metabolic sensor regulating cellular signalling, transcription and metabolism. Transcription factors and signalling pathways related to metabolism are modulated by N-acetyl-glucosamine (O-GlcNAc) modification. Aberrant regulation of O-GlcNAcylation is closely linked to insulin resistance, type 2 diabetes and obesity. Current evidence shows that increased O-GlcNAcylation negatively regulates insulin signalling, which is associated with insulin resistance and type 2 diabetes. Here, we aimed to evaluate the effects of Oga (also known as Mgea5) haploinsufficiency, which causes hyper-O-GlcNAcylation, on metabolism. Methods We examined whether Oga +/- mice developed insulin resistance. Metabolic variables were determined including body weight, glucose and insulin tolerance, metabolic rate and thermogenesis. Results Oga deficiency does not affect insulin signalling even at hyper-O-GlcNAc levels. Oga +/- mice are lean with reduced fat mass and improved glucose tolerance. Furthermore, Oga +/- mice resist high-fat diet-induced obesity with ameliorated hepatic steatosis and improved glucose metabolism. Oga haploinsufficiency potentiates energy expenditure through the enhancement of brown adipocyte differentiation from the stromal vascular fraction of subcutaneous white adipose tissue (WAT). Conclusions/interpretation Our observations suggest that O-GlcNAcase (OGA) is essential for energy metabolism via regulation of the thermogenic WAT program.close0

A 28 nt long synthetic 5^′UTR (synJ) as an enhancer of transgene expression in dicotyledonous plants

<p>Abstract</p> <p>Background</p> <p>A high level of transgene expression is required, in several applications of transgenic technology. While use of strong promoters has been the main focus in such instances, 5^′UTRs have also been shown to enhance transgene expression. Here, we present a 28 nt long synthetic 5^′UTR (synJ), which enhances gene expression in tobacco and cotton.</p> <p>Results</p> <p>The influence of synJ on transgene expression was studied in callus cultures of cotton and different tissues of transgenic tobacco plants. The study was based on comparing the expression of reporter gene <it>gus</it> and <it>gfp</it>, with and without synJ as its 5^′UTR. Mutations in synJ were also analyzed to identify the region important for enhancement. synJ, enhances gene expression by 10 to 50 fold in tobacco and cotton depending upon the tissue studied. This finding is based on the experiments comparing the expression of <it>gus</it> gene, encoding the synJ as 5^′UTR under the control of 35S promoter with expression cassettes based on vectors like pBI121 or pRT100. Further, the enhancement was in most cases equivalent to that observed with the viral leader sequences known to enhance translation like Ω and AMV. In case of transformed cotton callus as well as in the roots of tobacco transgenic plants, the up-regulation mediated by synJ was much higher than that observed in the presence of both Ω as well as AMV. The enhancement mediated by synJ was found to be at the post-transcriptional level. The study also demonstrates the importance of a 5^′UTR in realizing the full potential of the promoter strength. synJ has been utilized to design four cloning vectors: pGEN01, pBGEN02, pBGEN02-<it>hpt</it> and pBGEN02-<it>ALS</it>^<it>dm</it> each of which can be used for cloning the desired transgene and achieving high level of expression in the resulting transgenic plants.</p> <p>Conclusions</p> <p>synJ, a synthetic 5^′UTR, can enhance transgene expression under a strong promoter like 35S as well as under a weak promoter like nos in dicotyledonous plants. synJ can be incorporated as the 5^′UTR of transgenes, especially in cases where high levels of expression is required. A set of vectors has also been designed to facilitate this process.</p