Small P M, Shafer R W, Hopewell P C, Singh S P, Murphy M J, Desmond E, Sierra M F, Schoolnik G K
Department of Medicine, Stanford University, Calif.
N Engl J Med. 1993 Apr 22;328(16):1137-44. doi: 10.1056/NEJM199304223281601.
In the United States there have been recent outbreaks of multidrug-resistant tuberculosis. These outbreaks have primarily involved persons infected with the human immunodeficiency virus (HIV).
We collected clinical information on 17 patients seen at a New York City hospital who had repeatedly positive cultures for Mycobacterium tuberculosis. Analysis of restriction-fragment--length polymorphisms (RFLPs) was performed on serial isolates of M. tuberculosis obtained from these patients.
Six patients had isolates that remained drug-susceptible, and the RFLP patterns of these isolates did not change over time. Eleven patients had isolates that became resistant to antimicrobial agents. The RFLP patterns of the isolates from six of these patients remained essentially unchanged (two strains showed one additional band) despite the development of drug resistance. In five other patients, however, the RFLP patterns of the isolates changed dramatically at the time that drug resistance was detected. The change in the RFLP pattern of the isolate from one patient appeared to be the result of contamination during processing in the laboratory. In the remaining four patients, all of whom had advanced HIV disease, the clinical and microbiologic evidence was consistent with the presence of active tuberculosis caused by a new strain of M. tuberculosis.
Resistance to antituberculous drugs can develop not only in the strain that caused the initial disease, but also as a result of reinfection with a new strain of M. tuberculosis that is drug-resistant. Exogenous reinfection with multidrug-resistant M. tuberculosis can occur either during therapy for the original infection or after therapy has been completed.
在美国，近期出现了耐多药结核病的暴发。这些暴发主要涉及感染人类免疫缺陷病毒（HIV）的人群。
我们收集了纽约市一家医院诊治的17例结核分枝杆菌培养多次呈阳性患者的临床信息。对从这些患者获得的结核分枝杆菌系列分离株进行了限制性片段长度多态性（RFLP）分析。
6例患者的分离株仍对药物敏感，且这些分离株的RFLP模式未随时间变化。11例患者的分离株对抗菌药物产生了耐药性。其中6例患者的分离株尽管出现了耐药性，但其RFLP模式基本未变（2株显示有一条额外条带）。然而，在其他5例患者中，分离株的RFLP模式在检测到耐药性时发生了显著变化。1例患者分离株RFLP模式的改变似乎是实验室处理过程中污染所致。在其余4例均患有晚期HIV疾病的患者中，临床和微生物学证据均支持存在由一株新的结核分枝杆菌引起的活动性结核病。
耐抗结核药物的情况不仅可在引起初始疾病的菌株中出现，也可因再次感染一株耐药的新结核分枝杆菌菌株所致。耐多药结核分枝杆菌的外源性再次感染可发生在原感染治疗期间或治疗完成之后。
