Rapid emergence of blaCTX-M among Enterobacteriaceae in US medical centers:: Molecular evaluation from the MYSTIC program (2007)
Rapid emergence of blaCTX-M among Enterobacteriaceae in US medical centers:: Molecular evaluation from the MYSTIC program (2007)
复制标题
DOI：
10.1089/mdr.2008.0827
复制
发表时间：
2008-09-01
影响因子：
2.6
通讯作者：
Jones, Ronald N.
中科院分区：
文献类型：
--
作者：
Castanheira, Mariana;Mendes, Rodrigo E.;Jones, Ronald N.
对2007年MYSTIC项目期间在美国医疗中心回收的220株显示不同β-内酰胺耐药谱的革兰氏阴性分离株进行了评价，以确定是否存在选定的β-内酰胺酶基因。CTX-M编码基因在美国被认为是罕见的，在38.8%（28/70;三个物种）的超广谱β-内酰胺酶阳性分离株中检测到，并在80.0%的参与医院中观察到。CTX-M-14和CTX-M-15在多个机构（分别为8个和9个医疗中心）中发现，CTX-M-3仅在一个分离株中检出。在9株肠杆菌科菌株中鉴定出OXA-2和-10，在6株和4株分离株中分别鉴定出质粒介导的AmpC酶CMY-2和FOX-5，显示阴性棒杆菌抑制。在30.0%（15/50）的碳青霉烯类耐药不动杆菌中检测到编码OXA-23和-24的基因。菌株回顾性采样显示，自2004年以来，MYSTIC项目分离株中存在这些OXA酶。在大多数碳青霉烯类耐药肠杆菌科（通常为肺炎克雷伯菌）中观察到KPC丝氨酸碳青霉烯酶，证实了纽约市地区的流行病问题。肠杆菌科菌株中β-内酰胺酶的产生和可转移的喹诺酮类耐药基因（qnr; 6.7%）的相关性高于先前的报道。这项研究说明了一些β-内酰胺酶的出现和快速传播，如CTX-M，广谱苯唑西林酶和丝氨酸碳青霉烯酶，这些酶影响了2007年参与MYSTIC计划的许多美国医院对革兰氏阴性菌感染的治疗。
A total of 220 gram-negative isolates showing distinct beta-lactam resistance profiles recovered in U.S. medical centers during the MYSTIC Program 2007 were evaluated to determine the presence of selected beta-lactamase genes. CTX-M-encoding genes, considered rare in the United States, were detected in 38.8% (28/70; three species) of the extended spectrum beta-lactamase-positive isolates and were observed in 80.0% of the participating hospitals. CTX-M-14 and -15 were found in multiple institutions (eight and nine medical centers, respectively), and CTX-M-3 was detected in only one isolate. The OXA-2 and -10 were identified in nine Enterobacteriaceae strains, and plasmid-mediated AmpC enzymes CMY-2 and FOX-5 were identified in six and four isolates, respectively, displaying negative clavulanate inhibition. Genes encoding OXA-23 and -24 were detected in 30.0% (15/50) of carbapenem-resistant Acinetobacter spp. strains. Retrospective sampling showed that these OXA enzymes were present since 2004 in the MYSTIC Program isolates. The KPC serine carbapenemases were observed in the majority of the carbapenem-resistant Enterobacteriaceae (usually Klebsiella pneumoniae), confirming an epidemic problem in the New York City area. The association of beta-lactamase production and transferable quinolone resistance genes (qnr; 6.7%) in Enterobacteriaceae strains was higher than previously reported. This study illustrates the emergence and rapid dissemination of some beta-lactamases, such as CTX-M, broad-spectrum oxacillinases, and serine carbapenemases, that compromised the treatment of gram-negative infections in numerous U.S. hospitals participating in the MYSTIC Program in 2007.