Section of Infectious Diseases, University of Chicago, Chicago, IL, USA.
J Antimicrob Chemother. 2009 Dec;64(6):1291-8. doi: 10.1093/jac/dkp349. Epub 2009 Sep 24.
To compare the proportion of antimicrobial-resistant strains among bacterial isolates from younger and older hospital patients and to quantify changes in the proportion of antimicrobial-resistant strains in both groups over time.
A retrospective analysis of microbiology data from two centres in Maryland and Chicago was performed. Adult hospital inpatients with positive clinical cultures for specific antimicrobial-resistant bacterial pathogens between 1999 and 2005 (55 427 isolates) were included. The proportions of isolates not susceptible to specific antimicrobial agents were compared between patients > or =65 and <65 years. Additional analyses examined temporal trends in the frequency of resistance and the frequency of resistance among the oldest patients (> or =80 years), in bacteria isolated from blood cultures and in bacteria obtained from intensive care unit patients.
Heterogeneity was observed in the frequency of resistance among different bacteria between older and younger patients, between the two centres and over the study period. Staphylococcus aureus isolates were more likely to be resistant to methicillin when obtained from older patients at Chicago (50.9% versus 40.9%; P < 0.001). In contrast, younger patients yielded a greater proportion of enterococci resistant to vancomycin at Maryland (19.4% versus 16.5%; P = 0.009). Results were variable when resistance to fluoroquinolones, cephalosporins and imipenem were compared for Pseudomonas aeruginosa, Escherichia coli and Klebsiella spp.
Overall, advanced patient age was not uniformly associated with a greater likelihood of antimicrobial resistance among all bacterial pathogens. Moreover, the frequency of resistance in older and younger patients varied considerably at the two sites over the study period. Variability in the frequency of resistance precludes simplistic conclusions regarding the relationship between age and resistance.
比较年轻和年老住院患者分离的细菌中抗微生物药物耐药株的比例，并定量评估两组患者中耐药株比例随时间的变化。
对马里兰州和芝加哥两个中心的微生物学数据进行回顾性分析。纳入 1999 年至 2005 年间具有特定抗微生物药物耐药菌阳性临床培养的成年住院患者（55 427 株分离株）。比较年龄≥65 岁和＜65 岁患者中对特定抗微生物药物不敏感的分离株比例。另外的分析还检测了耐药频率和最年长患者（≥80 岁）中耐药频率的时间趋势，以及血培养分离的细菌和重症监护病房患者获得的细菌中的耐药频率。
在不同细菌中，老年和年轻患者之间、两个中心之间以及研究期间，耐药频率存在差异。在芝加哥，从老年患者中分离的金黄色葡萄球菌对甲氧西林的耐药率更高（50.9%对 40.9%；P＜0.001）。相比之下，在马里兰州，年轻患者分离的粪肠球菌对万古霉素的耐药率更高（19.4%对 16.5%；P=0.009）。比较铜绿假单胞菌、大肠埃希菌和克雷伯菌对氟喹诺酮类、头孢菌素类和亚胺培南的耐药率时，结果也各不相同。
总体而言，患者年龄的增加并不总是与所有细菌病原体抗微生物药物耐药的可能性增加相关。此外，在研究期间，两个地点的老年和年轻患者的耐药率差异很大。耐药频率的差异使得关于年龄与耐药之间关系的结论变得复杂。
