Saavedra S, Vera D, Ramírez-Ronda C H
Am J Med. 1986 Jun 30;80(6B):65-70. doi: 10.1016/0002-9343(86)90481-x.
Amikacin was instituted as the primary empiric aminoglycoside at the San Juan Veterans Administration Medical Center in January 1982; at that time, 16 percent of the strains at the hospital were gentamicin-resistant. A prospective surveillance study was designed to correlate detection of bacterial resistance with aminoglycoside use. In the current report, the baseline period, during which gentamicin was the first-line aminoglycoside, accounting for 61 percent of overall aminoglycoside use, is compared with the period from January 1982 to September 1985, during which the first-line aminoglycoside was amikacin, accounting for 85 percent of overall use. This study is ongoing. During the two periods, the patient population did not differ with regard to aminoglycoside therapy, indications, or overall aminoglycoside use (541 versus 680 patient days per month). Among the gram-negative bacilli isolated, the percent of strains resistant to amikacin was as follows: pre-baseline period/baseline period, 0.8/0.2 percent; amikacin-usage period, 3.6 percent. Resistance to gentamicin and tobramycin during the period of amikacin use decreased from 16 to 11 percent for gentamicin and from 17 to 11 percent for tobramycin. The decrease in resistance of the gram-negative bacilli to gentamicin varied among strains: the resistance of Escherichia coli decreased from 8 to 4 percent; that of Proteus mirabilis, from 12 to 5 percent; that of indole-positive Proteus, from 19 to 12 percent; that of Acinetobacter, from 57 to 23 percent; that of Citrobacter, from 15 to 7 percent; and that of Pseudomonas aeruginosa, from 24 to 16 percent. During the amikacin-usage period, amikacin resistance was unchanged for most strains, with the exception of P. aeruginosa, the resistance of which increased from 4.5 to 7.8 percent. Of the 4,795 strains isolated, 174 were resistant to amikacin; of these, 29 Pseudomonas strains were studied for all mechanisms of resistance. Changes in permeability were exhibited by 11 of the 29 strains; 14 strains exhibited the AAC(6')-I enzyme, 10 strains exhibited the APH(3')-II enzyme, and two strains exhibited ANT(2") in addition to some other unidentified mechanism. Multiple enzyme production was found in 15 of the strains. The use of amikacin as a first-line aminoglycoside is associated with a decrease in resistance to other aminoglycosides and a slight increase in overall resistance to amikacin among aerobic gram-negative bacilli. The usefulness of amikacin has not been affected at our institution.
1982年1月，阿米卡星成为圣胡安退伍军人管理局医疗中心主要的经验性氨基糖苷类药物；当时，该医院16%的菌株对庆大霉素耐药。一项前瞻性监测研究旨在将细菌耐药性的检测与氨基糖苷类药物的使用相关联。在本报告中，将以庆大霉素为一线氨基糖苷类药物（占氨基糖苷类药物总使用量的61%）的基线期与1982年1月至1985年9月期间（一线氨基糖苷类药物为阿米卡星，占总使用量的85%）进行比较。本研究正在进行中。在这两个时期，患者群体在氨基糖苷类药物治疗、适应证或氨基糖苷类药物总使用量方面没有差异（每月分别为541和680个患者日）。在分离出的革兰阴性杆菌中，对阿米卡星耐药的菌株百分比分别为：基线前期/基线期，0.8%/0.2%；阿米卡星使用期，3.6%。在阿米卡星使用期间，对庆大霉素和妥布霉素的耐药性从庆大霉素的16%降至11%，妥布霉素从17%降至11%。革兰阴性杆菌对庆大霉素的耐药性下降因菌株而异：大肠杆菌的耐药性从8%降至4%；奇异变形杆菌从12%降至5%；吲哚阳性变形杆菌从19%降至12%；不动杆菌从57%降至23%；柠檬酸杆菌从15%降至7%；铜绿假单胞菌从24%降至16%。在阿米卡星使用期间，除铜绿假单胞菌外，大多数菌株对阿米卡星的耐药性没有变化，铜绿假单胞菌的耐药性从4.5%增加到7.8%。在分离出的4795株菌株中，174株对阿米卡星耐药；其中，对29株铜绿假单胞菌菌株的所有耐药机制进行了研究。29株菌株中有11株表现出通透性变化；14株表现出AAC(6')-I酶，10株表现出APH(3')-II酶，2株除了一些其他未确定的机制外还表现出ANT(2")。15株菌株发现有多种酶产生。将阿米卡星用作一线氨基糖苷类药物与需氧革兰阴性杆菌对其他氨基糖苷类药物的耐药性降低以及对阿米卡星的总体耐药性略有增加有关。在我们机构，阿米卡星的有效性尚未受到影响。
