Nationwide spread of Klebsiella pneumoniae carbapenemase-2-producing K. pneumoniae sequence type 11 in Taiwan

摘要

Since the past decade, carbapenem-resistant Enter-obacteriaceae isolates, particularly Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae and New Delhi metallo-p-lactamase-1 (NDM-1)-producing Enter-obacteriaceae, have emerged in health care settings of many countries. Apart from NDM, which is endemic in the Indian subcontinent, KPC was first reported among K. pneumoniae in the United States in 2001 and has also been proven to possess great potential for intra- and interhospital dissemination worldwide. The first clinical KPC-producing K. pneumoniae isolate in Taiwan was obtained in 2010 from a patient with bacteremia who had just returned from Zhejiang Province, the epicenter of the KPC-2 endemic in China.4 For most clinical laboratories, however, it is difficult to judge the existence of carbape-nemases in Enterobacteriaceae through minimum inhibitory concentration (MIC) levels against carbapenem agents alone. In 2009, by means of the modified Hodge test, no ertapenem-nonsusceptible (NS; MIC > 0.25 (mug/mL) Enterobacteriaceae isolates of class A carbapenemase production were detected in intensive care units in Taiwan. However, using the MIC breakpoints recommended by the Clinical and Laboratory Standards Institute (CLSI) in 2011, we found alarmingly high rates of nonsusceptibility of Enterobacter cloacae and K. pneumoniae to ertapenem (40.5% and 24.5%, respectively). Subsequently, using the polymerase chain reaction method and electrophoresis analysis, two nationwide surveys in Taiwan investigated the 2011 prevalence rates of Enterobacteriaceae carriers of carbapenemases (class A, class B) and elucidated the main resistance mechanisms of carbapenem-NS Enterobacteriaceae isolates collected in 2010 and 2012, respectively.