Ashour Hossam M, el-Sharif Amany
Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University, Kasr El-Aini St, Cairo, Egypt 11562.
J Clin Oncol. 2007 Dec 20;25(36):5763-9. doi: 10.1200/JCO.2007.14.0947.
Cancer patients are particularly susceptible to nosocomial infections because of their compromised immune system, and because of the nature of treatment practices they experience. Recently, a shift of the microbial spectrum of cancer patients from gram-negative to gram-positive has been demonstrated. This study analyzed the distribution and the antimicrobial resistance of gram-positive bacteria isolated from cancer patients in Egypt.
We examined the microbial spectrum of gram-positive bacteria in patients with hematologic malignancies and solid tumors. In addition, we also studied the antimicrobial resistance of pathogens accounting for the majority of gram-positive infections in these cancer patients.
Most of gram-positive isolates from urinary tract (100%), respiratory tract (89.7%), and bloodstream infections (BSIs; 65.5%) were obtained from leukemic patients. All gram-positive isolates from skin infections were isolated from solid-tumor patients. In both leukemic and solid-tumor patients, gram-positive bacteria causing nosocomial BSI were mainly Coagulase-negative staphylococcus (CNS) and S. aureus, whereas gram-positive bacteria causing nosocomial RTI were mainly alpha-hemolytic streptococci and CNS. Gram-positive bacteria were not isolated from GI tract infections. S. aureus, CNS, and alpha-hemolytic streptococci demonstrated methicillin resistance (81.5%, 92.3%, and 90% resistance, respectively). S. aureus and CNS were susceptible to linezolid (15.4% and 0% resistance, respectively), and vancomycin (15.5% and 11% resistance, respectively).
This is the first study to report the emergence of vancomycin- and linezolid-resistant S. aureus in Egypt. Newer generation quinolones (moxifloxacin and gatifloxacin) were more active than older quinolones (ciprofloxacin and ofloxacin) against S. aureus and CNS, suggesting the use of newer generation quinolones in the prophylaxis of cancer patients.
癌症患者因其免疫系统受损以及所经历的治疗方式的性质，特别容易发生医院感染。最近，已证实癌症患者的微生物谱从革兰氏阴性菌向革兰氏阳性菌转变。本研究分析了从埃及癌症患者中分离出的革兰氏阳性菌的分布及抗菌药物耐药性。
我们检查了血液系统恶性肿瘤和实体瘤患者中革兰氏阳性菌的微生物谱。此外，我们还研究了这些癌症患者中导致大多数革兰氏阳性菌感染的病原体的抗菌药物耐药性。
大多数来自泌尿系统（100%）、呼吸道（89.7%）和血流感染（BSIs；65.5%）的革兰氏阳性分离株来自白血病患者。所有来自皮肤感染的革兰氏阳性分离株均来自实体瘤患者。在白血病和实体瘤患者中，导致医院血流感染的革兰氏阳性菌主要是凝固酶阴性葡萄球菌（CNS）和金黄色葡萄球菌，而导致医院呼吸道感染的革兰氏阳性菌主要是甲型溶血性链球菌和CNS。未从胃肠道感染中分离出革兰氏阳性菌。金黄色葡萄球菌、CNS和甲型溶血性链球菌表现出耐甲氧西林（分别为81.5%、92.3%和90%耐药）。金黄色葡萄球菌和CNS对利奈唑胺敏感（分别为15.4%和0%耐药），对万古霉素敏感（分别为15.5%和11%耐药）。
这是埃及首次报道出现耐万古霉素和耐利奈唑胺的金黄色葡萄球菌。新一代喹诺酮类药物（莫西沙星和加替沙星）对金黄色葡萄球菌和CNS的活性高于旧一代喹诺酮类药物（环丙沙星和氧氟沙星），提示在癌症患者的预防中使用新一代喹诺酮类药物。
