ackground（背景）
The increasing prevalence of resistance to established antibiotics among key bacterial respiratory tract pathogens, such as Streptococcus pneumoniae, is a major healthcare problem in the USA. （在美国，呼吸道致病菌如肺炎链球菌对目前的抗生素日益增加的耐药性已经成为一个主要的医疗问题。）The PROTEKT US study is a longitudinal surveillance study designed to monitor the susceptibility of key respiratory tract pathogens in the USA to a range of commonly used antimicrobials. （PROTEKT是一项长期的研究，旨在监测重要呼吸道致病菌对目前广泛使用的抗生素的敏感性。）Here, we assess the geographic and temporal trends in antibacterial resistance of S. （这里，我们对其耐药性趋势进行了初步的地区之间的评估。）pneumoniae isolates from patients with community-acquired respiratory tract infections collected between Year 1 (2000-2001) and Year 4 (2003-2004) of PROTEKT US. （我们收集了2000-2001和2003-2004的社区获得性呼吸道感染的肺炎链球菌样本。）
Methods（方法）
Antibacterial minimum inhibitory concentrations were determined centrally using the Clinical and Laboratory Standards Institute (CLSI) broth microdilution method;（遵循CLSI的标准用微量稀释法测定菌株的最小抑菌浓度。） susceptibility was defined according to CLSI interpretive criteria. （药敏数据按照CLSI的标准进行解释。）Macrolide resistance genotypes were determined by polymerase chain reaction.（用PCR分析菌株对大环内酯类抗生素耐药的基因型。）
Results（结果）
A total of 39,495 S. pneumoniae isolates were collected during 2000-2004. （2000-2004期间共收集了39495株肺链。）The percentage of isolates resistant to erythromycin, penicillin, levofloxacin, and telithromycin were 29.3 %, 21.2 %, 0.9 %, and 0.02 %, respectively, over the 4 years, with marked regional variability. （4年间总的耐药率分别是红霉素29.3%,青霉素21.2%,左氧氟沙星0.9%,泰里霉素0.02%,但地区差异很大。 ）The proportion of isolates exhibiting multidrug resistance (includes isolates known as penicillin-resistant S. pneumoniae and isolates resistant to >/=2 of the following antibiotics: penicillin; second-generation cephalosporins, e.g. cefuroxime; macrolides; tetracyclines; and trimethoprim-sulfamethoxazole) remained stable at ~30% over the study period.（多重耐药率保持稳定在30%左右，包括对青霉素耐药、对下列两种或更多的抗生素耐药：二代头孢、头孢呋辛，大环内酯类、四环素类，复方新诺明。） Overall mef(A) was the most common macrolide resistance mechanism. （总体上mefA耐药基因是最常见的大环内酯类耐药机制。）The proportion of mef(A) isolates decreased from 68.8% to 62.3% between Year 1 and Year 4, while the percentage of isolates carrying both erm(B) and mef(A) increased from 9.7% to 18.4%.（mefA的分离率由68.8%下降至62.3%，而同时携带ermB和mefA的分离率却由9.7%上升至18.4%） Over 99% of the erm(B)+mef(A)-positive isolates collected over Years 1-4 exhibited multidrug resistance.(99%的同时携带ermB和mefA的肺链表现为多重耐药性。) Higher than previously reported levels of macrolide resistance were found for mef(A)-positive isolates. （mefA阳性的菌株对大环内酯类耐药水平比先前报道的要高。）
Conclusions（结论）
Over the first 4 years of PROTEKT US, penicillin and erythromycin resistance among pneumococcal isolates has remained high.（PROTEKT头4年的研究中，青霉素和红霉素的耐药率仍然很高。） Although macrolide resistance rates have stabilized, the prevalence of clonal isolates, with a combined erm(B) and mef(A) genotype together with high-level macrolide and multidrug resistance, is increasing, and their spread may have serious health implications. （虽然大环内酯类耐药率保持稳定，但同时携带ermB和mefA基因型又对大环内酯类高水平耐药且合并多重耐药的菌株在增加，其克隆传播可能会带来非常严重的健康问题。）Telithromycin and levofloxacin both showed potent in vitro activity against S. pneumoniae isolates irrespective of macrolide resistance genotype.（泰利霉素和左氧氟沙星都对肺链有潜在的体外活性，不管其是否存在大环内酯类耐药基因。）
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发表于 2008-2-19 16:42
发表于 2008-2-21 10:20