Increased resistance rate to ceftazidime among blood culture isolates of ESBL-producing Escherichia coli in a university-affiliated hospital of China
The Journal of Antibiotics advance online publication, September 30 2015. doi:10.1038/ja.2015.100
Authors: Xiao-Yan Yuan, Dong-Ying Yu, Xue-Hong Qu, Xin-Qiang Xiao, Bo Bi, Sheng-Bo Sun, Ai-Ying Chang & Qi-bo Zhang
Non-antibiotic 12-membered macrolides: design, synthesis and biological evaluation in a cigarette-smoking model
The Journal of Antibiotics advance online publication, September 30 2015. doi:10.1038/ja.2015.91
Authors: Akihiro Sugawara, Hideaki Shima, Akito Sueki, Tomoyasu Hirose, Hidehito Matsui, Hayato Nakano, Hideaki Hanaki, Kiyoko S Akagawa, Satoshi Ōmura & Toshiaki Sunazuka
Streptanoate, a new anticancer butanoate from Streptomyces sp. DC3
The Journal of Antibiotics advance online publication, September 16 2015. doi:10.1038/ja.2015.95
Authors: Saisattha Noomnual, Nopporn Thasana, Pareenart Sungkeeree, Skorn Mongkolsuk & Suvit Loprasert
New cytotoxic spectinabilin derivative from ant-associated Streptomyces sp. 1H-GS5
The Journal of Antibiotics advance online publication, September 16 2015. doi:10.1038/ja.2015.99
Authors: Shuang-he Liu, Mei-dong Xu, Hui Zhang, Huan Qi, Ji Zhang, Chong-xi Liu, Ji-dong Wang, Wen-sheng Xiang & Xiang-jing Wang
Teixobactin is a recently described antibiotic of a new class produced by a hitherto undescribed soil microorganism (provisionally named Eleftheria terrae). It was isolated with a new tool, the iChip, that allowed the environmental bacterium to grow and for the antibiotic it produced to be isolated and subsequently identified. Teixobactin has activity against Gram-positive (but not Gram-negative) organisms and mycobacteria and a novel mode of action inhibiting peptidoglycan biosynthesis. In vitro no teixobactin-resistant Staphylococcus aureus or Mycobacterium tuberculosis were selected. In experimental infections of MRSA and Streptococcus pneumoniae in mice, teixobactin was effective at reducing the bacterial load. Although teixobactin is at an early stage of development and there are no guarantees it will make it to market, the use of the iChip will hopefully result in the discovery of further potential new antibiotics.
Mupirocin 2% ointment is used either alone or with skin antiseptics as part of a comprehensive MRSA decolonization strategy. Increased mupirocin use predisposes to mupirocin resistance, which is significantly associated with persistent MRSA carriage. Mupirocin resistance as high as 81% has been reported. There is a strong association between previous mupirocin exposure and both low-level and high-level mupirocin resistance. High-level mupirocin resistance (mupA carriage) is also linked to MDR. Among MRSA isolates, the presence of the qacA and/or qacB gene, encoding resistance to chlorhexidine, ranges from 65% to 91%, which, along with mupirocin resistance, is associated with failed decolonization. This is of significant concern for patient care and infection prevention and control strategies as both these agents are used concurrently for decolonization. Increasing bacterial resistance necessitates the discovery or development of new antimicrobial therapies. These include, for example, polyhexanide, lysostaphin, ethanol, omiganan pentahydrochloride, tea tree oil, probiotics, bacteriophages and honey. However, few of these have been evaluated fully or extensively tested in clinical trials and this is required to in part address the implications of mupirocin resistance.
The NNRTI efavirenz has long been one of the most frequently employed antiretroviral drugs in the multidrug regimens used to treat HIV infection, in accordance with its well-demonstrated antiretroviral efficacy and favourable pharmacokinetics. However, growing concern about its adverse effects has sometimes led to efavirenz being replaced by other drugs in the initial treatment selection or to switching of therapy to efavirenz-free regimens in experienced patients. Neurological and neuropsychiatric reactions are the manifestations most frequently experienced by efavirenz-treated patients and range from transitory effects, such as nightmares, dizziness, insomnia, nervousness and lack of concentration, to more severe symptoms including depression, suicidal ideation or even psychosis. In addition, efavirenz has recently been associated with mild/moderate neurocognitive impairment, which is of specific relevance given that half of the patients receiving ART eventually suffer some form of HIV-associated neurocognitive disorder. The mechanisms responsible for efavirenz-induced neurotoxicity are unclear, although growing evidence points to disturbances in brain mitochondrial function and bioenergetics. This review offers a comprehensive overview of the current evidence on the interaction that efavirenz displays with the CNS, including the penetration and concentration of the drug in the brain. We discuss the prevalence, types and specificities of its side effects and recently uncovered cellular mechanisms that may be involved in their development.
