Ahmad S, Khan Z, Mustafa A S, Khan Z U
Department of Microbiology Faculty of Medicine, Kuwait University, PO Box 24923, Safat 13110, Kuwait.
Med Mycol. 2003 Dec;41(6):487-93. doi: 10.1080/1369378031000147458.
The incidence of Candida infections in intensive care units (ICU) is increasing. Although most cases of candidemia are caused by commensal strains colonizing the patients' own body sites, recent studies have suggested that the source of Candida infection can also be exogenous. This study was carried out to prospectively investigate the frequency of Candida colonization among patients and health care personnel of an ICU of a teaching hospital in Kuwait. A total of 57 patients and 45 nurses were investigated. Candida isolates were identified to the species level by the Vitek identification system. The typing of selected isolates was performed by randomly amplified polymorphic DNA (RAPD) using three different arbitrary primers (CARAPD1, AP3, CT5). Of the 526 samples collected from 57 patients, 180 (34%) yielded Candida species. These included 112 (62%) C. albicans, 37 (21%) C. glabrata, 15 (8%) C. parapsilosis, 11 (6%) C. tropicalis, 3 (2%) C. krusei and 2 (1%) C. lusitaniae isolates. Thirty-seven patients (65%) were colonized by Candida at some point of stay in the ICU. Seven (12%) patients yielded more than one Candida species from the sites/specimens tested. The frequency of Candida isolation was highest from oropharynx, followed by rectum, groin, urine and trachea. Twenty-five (6%) of the 448 swabs from the nurses yielded Candida and included C. albicans (n = 16), C. parapsilosis (n = 4) and C. famata (n = 5). While all the three primers yielded varying patterns in RAPD analyses for each Candida species, the results obtained by AP3 were most discriminatory. The data showed that the colonizing Candida isolates recovered from various body sites of the patients, as well as the nursing staff, were different. However, when RAPD profiles of three blood culture isolates from candidemic patients were analyzed, the DNA fingerprint produced by one C. parapsilosis blood culture isolate was similar to C. parapsilosis recovered from the hands of two nurses, suggesting exogenous acquisition of infection.
重症监护病房（ICU）中念珠菌感染的发生率正在上升。虽然大多数念珠菌血症病例是由定植于患者自身身体部位的共生菌株引起的，但最近的研究表明，念珠菌感染的来源也可能是外源性的。本研究旨在前瞻性调查科威特一家教学医院ICU患者和医护人员中念珠菌定植的频率。共调查了57例患者和45名护士。念珠菌分离株通过Vitek鉴定系统鉴定到种水平。使用三种不同的任意引物（CARAPD1、AP3、CT5）通过随机扩增多态性DNA（RAPD）对选定的分离株进行分型。从57例患者采集的526份样本中，180份（34%）培养出念珠菌属。其中包括112株（62%）白色念珠菌、37株（21%）光滑念珠菌、15株（8%）近平滑念珠菌、11株（6%）热带念珠菌、3株（2%）克柔念珠菌和2株（1%）葡萄牙念珠菌分离株。37例患者（65%）在ICU住院期间的某个时间点被念珠菌定植。7例（12%）患者从检测的部位/样本中分离出不止一种念珠菌。念珠菌分离频率最高的部位是口咽部，其次是直肠、腹股沟、尿液和气管。护士的448份拭子中有25份（6%）培养出念珠菌，包括白色念珠菌（n = 16）、近平滑念珠菌（n = 4）和法塔念珠菌（n = 5）。虽然所有三种引物在每种念珠菌的RAPD分析中都产生了不同的模式，但AP3获得的结果最具鉴别力。数据显示，从患者以及医护人员的不同身体部位分离出的定植念珠菌分离株是不同的。然而，当分析念珠菌血症患者的三份血培养分离株的RAPD图谱时，一株近平滑念珠菌血培养分离株产生的DNA指纹与从两名护士手上分离出的近平滑念珠菌相似，提示感染为外源性获得。
