Fluoroquinolones are associated with delayed treatment and resistance in tuberculosis: a systematic review and meta-analysis

SummaryBackgroundCurrent guidelines for treating community-acquired pneumonia recommend the use of fluoroquinolones for high-risk patients. Previous studies have reported controversial results as to whether fluoroquinolones are associated with delayed diagnosis and treatment of pulmonary tuberculosis (TB) and the development of fluoroquinolone-resistant Mycobacterium tuberculosis. We performed a systematic review and meta-analysis to clarify these issues.MethodsThe following databases were searched through September 30, 2010: PubMed, EMBASE, CINAHL, Cochrane Library, Web of Science, BIOSIS Previews, and the ACP Journal Club. We considered studies that addressed the issues of delay in diagnosis and treatment of TB and the development of resistance.ResultsNine eligible studies (four for delays and five for resistance issues) were included in the meta-analysis from the 770 articles originally identified in the database search. The mean duration of delayed diagnosis and treatment of pulmonary TB in the fluoroquinolone prescription group was 19.03 days, significantly longer than that in the non-fluoroquinolone group (95% confidence interval (CI) 10.87 to 27.18, p<0.001). The pooled odds ratio of developing a fluoroquinolone-resistant M. tuberculosis strain was 2.70 (95% CI 1.30 to 5.60, p=0.008). No significant heterogeneity was found among studies in the meta-analysis.ConclusionsEmpirical fluoroquinolone prescriptions for pneumonia are associated with longer delays in diagnosis and treatment of pulmonary TB and a higher risk of developing fluoroquinolone-resistant M. tuberculosis

Deactivation of TBP contributes to SCA17 pathogenesis

Spinocerebellar ataxia type 17 (SCA17) is an autosomal dominant cerebellar ataxia caused by the expansion of polyglutamine (polyQ) within the TATA box-binding protein (TBP). Previous studies have shown that polyQexpanded TBP forms neurotoxic aggregates and alters downstream genes. However, how expanded polyQ tracts affect the function of TBP and the link between dysfunctional TBP and SCA17 is not clearly understood. In this study, we generated novel Drosophila models for SCA17 that recapitulate pathological features such as aggregate formation, mobility defects and premature death. In addition to forming neurotoxic aggregates, we determined that polyQ-expanded TBP reduces its own intrinsic DNA-binding and transcription abilities. Dysfunctional TBP also disrupts normal TBP function. Furthermore, heterozygous dTbp amorph mutant flies exhibited SCA17-like phenotypes and flies expressing polyQ-expanded TBP exhibited enhanced retinal degeneration, suggesting that loss of TBP function may contribute to SCA17 pathogenesis. We further determined that the downregulation of TBP activity enhances retinal degeneration in SCA3 and Huntington&apos;s disease fly models, indicating that the deactivation of TBP is likely to play a common role in polyQ-induced neurodegeneration

Case report: Infective endocarditis caused by Brevundimonas vesicularis

BACKGROUND: There are few reports in the literature of invasive infection caused by Brevundimonas vesicularis in patients without immunosuppression or other predisposing factors. The choice of antimicrobial therapy for bacteremia caused by the pathogen requires more case experience to be determined. CASE PRESENTATION: The case of a 40-year-old previously healthy man with subacute endocarditis proposed to be contributed from an occult dental abscess is described. The infection was found to be caused by B. vesicularis on blood culture results. The patient recovered without sequelae after treatment with ceftriaxone followed by subsequent ciprofloxacin therapy owing to an allergic reaction to ceftriaxone and treatment failure with ampicillin/sulbactam. CONCLUSION: To our knowledge, this is the first report of B. vesicularis as a cause of infective endocarditis. According to an overview of the literature and our experience, we suggest that third-generation cephalosporins, piperacillin/tazobactam, and ciprofloxacin are effective in treating invasive B. vesicularis infections, while the efficacy of ampicillin-sulbactam needs further evaluation

Methicillin-resistant Staphylococcus aureus and Acinetobacter baumannii on computer interface surfaces of hospital wards and association with clinical isolates

<p>Abstract</p> <p>Background</p> <p>Computer keyboards and mice are potential reservoirs of nosocomial pathogens, but routine disinfection for non-water-proof computer devices is a problem. With better hand hygiene compliance of health-care workers (HCWs), the impact of these potential sources of contamination on clinical infection needs to be clarified.</p> <p>Methods</p> <p>This study was conducted in a 1600-bed medical center of southern Taiwan with 47 wards and 282 computers. With education and monitoring program of hand hygiene for HCWs, the average compliance rate was 74% before our surveillance. We investigated the association of methicillin-resistant <it>Staphylococcus aureus </it>(MRSA), <it>Pseudomonas aeruginosa </it>and <it>Acinetobacter baumannii</it>, three leading hospital-acquired pathogens, from ward computer keyboards, mice and from clinical isolates in non-outbreak period by pulsed field gel electrophoresis and antibiogram.</p> <p>Results</p> <p>Our results revealed a 17.4% (49/282) contamination rate of these computer devices by <it>S. aureus</it>, <it>Acinetobacter </it>spp. or <it>Pseudomonas </it>spp. The contamination rates of MRSA and <it>A. baumannii </it>in the ward computers were 1.1% and 4.3%, respectively. No <it>P. aeruginosa </it>was isolated. All isolates from computers and clinical specimens at the same ward showed different pulsotypes. However, <it>A. baumannii </it>isolates on two ward computers had the same pulsotype.</p> <p>Conclusion</p> <p>With good hand hygiene compliance, we found relatively low contamination rates of MRSA, <it>P. aeruginosa </it>and <it>A. baumannii </it>on ward computer interface, and without further contribution to nosocomial infection. Our results suggested no necessity of routine culture surveillance in non-outbreak situation.</p

Study on Nano Mechanical Properties of Softwood cell Walls by Nanoindentation

隨著科技的進步，材料科學研究的方向已從大尺度往微觀科技發展，原子力顯微鏡（Atomic force microscopy, AFM）以原子間凡得瓦力（Van der Waals force）為探測媒介，可運用於奈米壓痕技術（nanoindentation），對材料的力學性質與結構做深入分析，進而了解材料的表面性質，並結合奈米壓痕之力學特性，對材料做出最佳的研究與應用，在學術與工業應用上皆具發展潛力。 本研究透過奈米壓痕測試與AFM原子力顯微鏡進行觀測，對臺灣針葉樹種的細胞壁S2層進行奈米性質研究，配合木材之生理特質如木質素與微纖維傾斜角（microfibril angle，MFA）進行比較；結果顯示，木材微觀春秋材力學性質特性存在著很高的變異性，受木材組成分與生理結構微妙變化的影響，亦可能因為壓痕試驗參數設定的影響造成塑性變形；而木材的彈性係數性質與理論模型與考量探針幾何效應所推算的趨勢相近，可以推論出，在微觀尺度下，木材的彈性係數性質和巨觀性質相同，隨MFA增加而降低，但由於尺度細微，所以趨勢緩和許多；此外，木材微觀硬度大致隨MFA增加而降低，但仍有偏離趨勢的樣本點，考量木材為非均質的生物性材料，可以推論木材之微觀硬度是同時受到基質與纖維，再加上非均質性材料特性共同影響的力學性質。 由實驗的結果可以了解，木材在微觀尺度下的性質量測需考量的變因較巨觀量測複雜許多，也不如巨觀性質有較為一致的結果，故木材的微觀性質日後仍有很大的研究潛力。With the progress of technology, the trend of material science has shifted from macro-scale to micro-scale study. Atomic force microscopy (AFM), which probes via the Van der Waals force between atoms, can be applied in nanoindentation technology and have detailed analysis of the mechanical properties and the structure of materials. With the understanding of the surface properties and nanoindentation mechanics, we can make the best use of materials in academic research and industrial applications. It has large potential in both two fields. The S2 cell wall layer of common softwood species in Taiwan are studied through nanoindentation in our study. The micro-mechanics and biological properties such as lignin content and microfibril angles (MFA) are studied. The results indicate that there are high variability of the mechanical properties between early and latewood in micro-scale. It is affected by the differences of wood components and structures. Some plastic deformations may also exist due to the effect of indentation loading parameters. The trend of elastic modulus is close to the model calculation and the consideration of the geometry of indentation probes. It decreases with the increase of MFA, but shows a more gentle curve than macro study due to micro-scale observations. Furthermore, the hardness in micro scale is generally decrease with the increasing MFA, but some deviating samples exist. Considering the material properties of wood, we can infer that the micro hardness is affected by matrix, structure, and the inhomogenerous nature of wood. From the results of our study, the mechanical properties of wood in micro scale are much more complex than macro ones. And there is also high variability exist. The study on the mechanical properties of wood in micro scale still has large potential in the future. Our study provides a preliminary research on the material preparation and mechanical properties for the nanoindentation of Taiwanese tree species, which serves as references of further researches in the future

Hemorrhagic Bullae Caused by Bacteroides fragilis in a Patient with Intra-abdominal Infection

Skin manifestations due to intra-abdominal infection are uncommon but could be a warning sign of severe infection. We report a 58-year-old uremic female who had acute cholecystitis and pneumatosis intestinalis. She developed periumbilical hemorrhagic bullae and finally had a fatal outcome with medical therapy. Severe intra-abdominal infection such as pneumatosis intestinalis should be suspected when periumbilical bullae increase in size

Gemifloxacin, a Fluoroquinolone Antimicrobial Drug, Inhibits Migration and Invasion of Human Colon Cancer Cells

Gemifloxacin (GMF) is an orally administered broad-spectrum fluoroquinolone antimicrobial agent used to treat acute bacterial exacerbation of pneumonia and bronchitis. Although fluoroquinolone antibiotics have also been found to have anti-inflammatory and anticancer effects, studies on the effect of GMF on treating colon cancer have been relatively rare. To the best of our knowledge, this is the first report to describe the antimetastasis activities of GMF in colon cancer and the possible mechanisms involved. Results have shown that GMF inhibits the migration and invasion of colon cancer SW620 and LoVo cells and causes epithelial mesenchymal transition (EMT). In addition, GMF suppresses the activation of NF-κB and cell migration and invasion induced by TNF-α and inhibits the TAK1/TAB2 interaction, resulting in decreased IκB phosphorylation and NF-κB nuclear translocation in SW620 cells. Furthermore, Snail, a critical transcriptional factor of EMT, was downregulated after GMF treatment. Overexpression of Snail by cDNA transfection significantly decreases the inhibitory effect of GMF on EMT and cell migration and invasion. In conclusion, GMF may be a novel anticancer agent for the treatment of metastasis in colon cancer

Cat Scratch Disease from a Domestic Dog

Cat scratch disease (CSD), caused by Bartonella henselae, is a zoonosis and characterized by self-limited lymphadenopathy. It is transmitted commonly by scratch or bite from cats or kitten. We report an unusual case of CSD caused by a domestic dog scratch that we believe is the first report in Taiwan. A 23-year-old healthy woman developed cervical lymphadenopathy, mild fever, headache, and malaise 3 days after dog scratch. Her symptoms improved after azithromycin treatment. Serology proved B. henselae infection. The owners of a domestic dog might be at risk of “cat” scratch disease. [J Formos Med Assoc 2007;106 (2 Suppl):S65-S68