Epidemiologic Study on Ceftazidime-resistant Pseudomonas aeruginosa Infections in an Infensive Care Burn Unit

對多種藥物具抗藥性之綠膿桿菌長期 存在於燒燙傷病人身上，在過去之文獻尚 未看到，由本院近年在加護病房3 個燒燙 傷病患身上可分離出39 株此類細菌。我們 以各種不同方法如血清型、抗藥型和基因 型做這些細菌之分型發現有一菌株，屬於 綠膿桿菌04 造成群突發，由此菌株長期存 活於此3 病患之身上（血液、導管、傷口、 痰等檢體），此3 個病患在住院期間長期 接受抗生素治療，呼吸器和各種導管，和 過去幾年分離之菌株比較，我們發現此一 引起群突發之菌株在1996 年即在該加護病 房內分離出。Long-term colonization of various body sites with subsequent severe infections in burn patients by a multidrug-resistant Pseudomonas aeruginosa clone (resistant to piperacillin, cefoperazone, ceftazidime, aztreonam, imipenem, cefepime, cefpirome, ofloxacin, ciprofloxacin, minocycline, and aminoglycosides) has not been previously reported. Thirty-nine isolates of multidrugresistant P. aeruginosa (resistant to ceftazidime and at least three of the agents listed above) recovered from various clinical samples of three patients in an intensive care burn unit, and seven preserved isolates recovered from six patients in other medical wards at National Taiwan University Hospital were studied for their epidemiological relatedness. The epidemic could be attributed to a multidrug-resistant P. aeruginosa clone belonging to serogroup O:F (serogroup O:4) by means of antimicrobial susceptibility, O-serogrouping, and random amplified polymorphic DNA (RAPD) patterns generated by arbitrarily primed PCR (APPCR) of the isolates. The epidemic strain persisted in the three patients for weeks to months; in the meanwhile these patients had received multiple antimicrobial agents for management of intervenient episodes of invasive infections (bacteremia, ventilatorassociated pneumonia, and/or catheter-related sepsis) caused by this strain, as well as concomitant infections due to other organisms. The strain had been isolated only once previously from a burn patient of the unit in December 1996. The present study describing a small outbreak due to P. aeruginosa documents that a single clone of multidrug-resistant P. aeruginosa can cause long-term persistence in different body sites of burn patients and subsequently result in various severe infections