Sugarman B, Pesanti E
Rev Infect Dis. 1980 Mar-Apr;2(2):153-68. doi: 10.1093/clinids/2.2.153.
In two patients development of resistance to antibiotics by initially sensitive infecting organisms was associated with relapse or persistence of active infection. The first patient developed Staphylococcus epidermidis resistant to chloramphenicol during therapy with this agent for an infection that followed a cerebrospinal fluid shunt, and the second patient developed bacteremia due to ampicillin-resistant Salmonella during therapy with ampicillin. Treatment failure resulting from in vivo development of resistance to antimicrobial agents has been described for most of the major classes of antiinfective drugs and for numerous microorganisms. Although in many of these instances reinfection with a resistant organism cannot be excluded, there are many examples of apparent mutation or initial infection with both sensitive and resistant bacterial populations that is followed by selective multiplication of the resistant population or acquisition of resistance by an initially sensitive infecting organism. This phenomenon can be a cause of treatment failure and has appeared in patients in whom, by available tests, drug levels were found adequate. Isolation days after the institution of antimicrobial therapy of what appears to be the same organism as was initially recovered should prompt repeated sensitivity tests, at least to the agents being administered, if the patient's clinical course has not been one of satisfactory improvement.
在两名患者中，最初敏感的感染病原体对抗生素产生耐药性与活动性感染的复发或持续存在有关。第一名患者在使用氯霉素治疗因脑脊液分流术后感染期间，感染的表皮葡萄球菌对氯霉素产生了耐药性；第二名患者在使用氨苄西林治疗期间，因感染了对氨苄西林耐药的沙门氏菌而发生菌血症。对于大多数主要类别的抗感染药物以及众多微生物，都曾描述过因体内对抗菌药物产生耐药性而导致治疗失败的情况。尽管在许多此类病例中不能排除再次感染耐药病原体，但有许多明显的突变或最初感染时既有敏感菌又有耐药菌群体的例子，随后耐药菌群体选择性增殖或最初敏感的感染病原体获得耐药性。这种现象可能是治疗失败的原因，并且在通过现有检测发现药物水平足够的患者中也出现过。如果患者的临床病程没有出现令人满意的改善，那么在开始抗菌治疗数天后分离出看似与最初分离出的相同病原体时，应至少对正在使用的药物进行重复药敏试验。
