Antibiotic resistance to Propionobacterium acnes: worldwide scenario,diagnosis and management

Antibiotic resistance in cutaneous Propionobacterium is a global problem. As a general rule, resistance levels are high to macrolides, trimethoprim/sulfamethoxazole and clindamycin, while tetracyclines and levofloxacin have low resistance potential. Newer preparations like doxycycline MR and doxycycline 20 mg are subantimicrobial and may not lead to resistance. Sampling techniques are crucial to determine resistance. Genomic evaluation using 16S ribosomal RNA gene sequencing can be useful in diagnosing mutations and mapping phylotypes of Propionobacterium acnes. Resistance may lead to slow response and relapses. Apart from benzoyl peroxide, azelaic acid, topical dapsone, oral zinc and retinoids, novel molecules with little resistance potential include octadecenedioic acid, phytosphingosine, lauric acid, retapamulin, resveratrol, T-3912 and NB-003. The use of oral retinoids and non-antibiotics like zinc can prevent resistance and help reduce the dependence on antibiotics.     

Clostridium difficile PCR ribotypes in calves, Canada

We investigated Clostridium difficile in calves and the similarity between bovine and human C. difficile PCR ribotypes by conducting a case-control study of calves from 102 dairy farms in Canada. Fecal samples from 144 calves with diarrhea and 134 control calves were cultured for C. difficile and tested with an ELISA for C. difficile toxins A and B. C. difficile was isolated from 31 of 278 calves: 11 (7.6%) of 144 with diarrhea and 20 (14.9%) of 134 controls (p = 0.009). Toxins were detected in calf feces from 58 (56.8%) of 102 farms, 57 (39.6%) of 144 calves with diarrhea, and 28 (20.9%) of 134 controls (p = 0.0002). PCR ribotyping of 31 isolates showed 8 distinct patterns; 7 have been identified in humans, 2 of which have been associated with outbreaks of severe disease (PCR types 017 and 027). C. difficile may be associated with calf diarrhea, and cattle may be reservoirs of C. difficile for humans.     

甲磺酸左氧氟沙星中有机溶剂残留量的气相色谱法测定

目的:建立甲磺酸左氧氟沙星中有机溶剂残留量的测定方法。方法:采用毛细管气相色谱法,色谱柱为HP-5毛细管柱(30m×0.32mm×0.25μm),柱温均为50℃,FID检测器,以N,N-二甲基甲酰胺为溶剂,载气为N2,进样口温度200℃,检测器温度300℃,分流比80:1,进样量1μL。结果:2种有机溶剂分离完全,且线性关系良好,线性范围分别为乙醇125.2～2003.2mg/L,正丁醇125.2～2002.4mg/L,乙醇和正丁醇的线性相关系数分别为0.9998和0.9996,平均回收率分别为99.54%、101.11%,最低检测限分别为7.1ng、11ng。结论:该方法灵敏、准确、可靠,适用于甲磺酸左氧氟沙星中有机溶剂残留量的检测。     

左氧氟沙星治疗老年社区获得性肺炎临床观察

目的了解左氧氟沙星治疗老年社区获得性肺炎（CAP）的临床有效性和毒副作用。方法调查我院2006年5月～2008年5月治疗的老年CAP患者36例,全部病例应用左氧氟沙星,每日一次500mg静点,疗程5～14天。结果22例痰培养检出多药耐药的肺炎链球菌,8例检出铜绿假单胞菌,6例检出流感嗜血杆菌,临床有效率75．0％;细菌清除率82．1％;表现有腹泻、皮疹、肾损害各为2例,占16．7％。结论左氧氟沙星治疗老年CAP疗效好,毒副作用相对较低。     

Resistance to metronidazole, clarithromycin and levofloxacin of Helicobacter pylori before and after clarithromycin-based therapy in Taiwan

Background and Aim:  Clarithromycin-based triple therapy has been commonly applied as the first-line therapy for Helicobacter pylori eradication. Levofloxacin could serve as an alternative in either first-line or second-line regimens. This study surveyed the prevalence of levofloxacin resistance of H. pylori isolates in naive patients and in patients with a failed clarithromycin-based triple therapy.
Methods:  The study collected the H. pylori isolates from 180 naive patients and 47 patients with a failed clarithromycin-based triple therapy. Their in vitro antimicrobial resistance was determined by E -test.
Results:  The naive H. pylori isolates had resistance rates for amoxicillin, levofloxacin, clarithromycin and metronidazole of 0%, 9.4%, 10.6% and 26.7%, respectively. An evolutional increase of the primary levofloxacin resistance was observed in isolates collected after 2004, as compared to isolates collected before 2004 (16.3% vs 3.2%, P  = 0.003). There was no evolutional increment of the primary clarithromycin resistance. The clarithromycin resistance elevated significantly after a failed clarithromycin-based triple therapy (78.7% vs 10.6%, P  < 0.001). The post-treatment isolates remained to have a levofloxacin resistance rate of near 17%, but the levofloxacin-resistant isolates were correlated with a higher incidence of metronidazole resistance ( P  = 0.023). No strain was found to be resistant to amoxicillin even after eradication failure.
Conclusion:  The levofloxacin resistance of naive H. pylori remains less than 10% in Taiwan. With relatively lower resistance to levofloxacin than to metronidazole of the H. pylori isolates collected after a failed clarithromycin-based therapy, proton pump inhibitor–levofloxacin–amoxicillin may be an alternative choice to serve as the second-line therapy.     

顶空毛细管气相法测定盐酸左氧氟沙星中有机溶剂的残留量

目的测定盐酸左氧氟沙星中有机溶剂的残留量。方法采用顶空进样程序升温法,FID检测器,色谱柱为HP-5毛细管柱（30m×0.32mm,0.25μm）。结果乙醇和N,N-二甲基甲酰胺（DMF）的线性相关系数分别为0.9996和0.9994,平均加样回收率为99.57%和98.89%,RSD为2.5%和1.1%（n=5）。结论所用方法简便、准确,灵敏度高,适用于盐酸左氧氟沙星中有机溶剂残留量的测定。     

Novel mucoadhesive polysaccharide isolated from Bletilla striata improves the intraocular penetration and efficacy of levofloxacin in the topical treatment of experimental bacterial keratitis

Objectives The objective of the present study was to evaluate a novel mucoadhesive polymer extracted from Bletilla striata for ocular delivery of 0.5% levofloxacin in rabbits, and to determine its improved efficacy against experimental keratitis. Methods B. striata polysaccharide (BsP) was subjected to cell cytotoxicity and ferning tests. The pharmacokinetics and bioavailability of topically applied 0.5% levofloxacin‐BsP eye drops was investigated and compared with 0.5% levofloxacin eye drops (Cravit). Experimental Staphylococcus aureus keratitis was induced and treated with levofloxacin or levofloxacin‐BsP eye drops. Key findings BsP markedly increased the proliferative capacity of a human corneal endothelial cell line. The ferning test showed that BsP exhibited optimal performance as a tear fluid. The polysaccharides significantly increased intra‐aqueous penetration and corneal accumulation in rabbits. Treatment with levofloxacin‐BsP reduced the number of organisms more significantly than eye drops containing levofloxacin alone. Conclusions BsP appears to be a promising candidate as a vehicle for topical ophthalmic drug delivery, especially for antibiotics.     

不同海水浸泡时间对左氧氟沙星在腹部开放伤比格犬体内的药动学影响

目的建立腹部开放性创伤合并海水浸泡比格犬动物模型,研究左氧氟沙星（LVFX）在腹部开放性损伤合并海水浸泡比格犬与正常比格犬中的药动学变化。方法 12只比格犬随机分为3组,每组4只。A组为正常对照组,B组为腹部开放性创伤合并海水浸泡45 min组,C组为腹部开放性创伤合并海水浸泡90 min组。3组动物给药方案为：静脉输注LVFX25 mg/kg,60 min输注完毕。实验进程中监测实验动物体温。采用HPLC测定LVFX浓度;3P97计算药动学参数。结果腹部开放性创伤合并海水浸泡比格犬在浸泡过程中和出水后体温显著下降,且随浸泡时间增加而下降幅度增加。LVFX在比格犬体内呈二室模型,A、B和C组药动学参数分别为：Cmax（30.05±1.75）、（36.10±4.74）和（42.34±4.19）mg/L,t1/2β（8.23±0.65）、（11.02±0.54）和（13.19±3.87）h,AUC（247.00±14.10）、（345.22±56.68）和（417.79±83.32）mgoh/L,Vc（6.97±2.02）、（6.68±1.67）和（7.82±1.62）L,ClS（1.20±0.15）、（1.06±0.12）和（0.92±0.15）L/h。与A组比较,B组t1/2β和AUC显著增加（P〈0.05）;C组t1/2β、Cmax和AUC（t1/2β,P〈0.01;Cmax,AUC,P〈0.05）显著增加。与B组比较,C组t1/2β（P〈0.05）差异明显。结论腹部开放性创伤合并海水浸泡比格犬体内LVFX代谢消除随浸泡时间延长而明显减慢,其机制可能与浸泡导致的低体温状况有关。     

MP-376 (Aeroquin) for chronic Pseudomonas aeruginosa infections

Introduction: The chronic airway infection with Pseudomonas aeruginosa (PA) is a risk factor for rapid disease progression in various chronic pulmonary diseases including cystic fibrosis or chronic obstructive pulmonary disease. Inhaled antibiotics are able to treat effectively such chronic airway infections, and MP-376 is currently in late-stage clinical development for such an indication.

Areas covered: Review of the existing preclinical and clinical data on MP-376, with a focus on the efficacy and safety of the compound on chronic airways infections due to PA.

Expert opinion: Chronic airways infection with PA represents a therapeutic challenge because of its own complex mechanisms of defense, because of the rapid development of antibiotic resistance and by the fact that systemic antibiotics are not always able to achieve appropriate concentrations at lung level. Inhaled antibiotics (tobramycin, aztreonam, etc.) represent optimal alternatives to their systemic homologs due to their better penetrability in the lungs and due to the lower systemic exposure. Inhaled levofloxacin which is currently investigated for chronic airways infection might be another possible antipseudomonal inhaled therapy.