Strategic measures for the control of surging antimicrobial resistance in Hong Kong and mainland of China

Cheng, Vincent CC; Wong, Sally CY; Ho, Pak-Leung; Yuen, Kwok-Yung

The burden of antibiotic resistance is serious in mainland China. According to data from the Shanghai Bacterial Resistance Surveillance Project involving 23 hospitals since 1989, and CHINET, a national bacterial resistance surveillance project in China involving 15 tertiary hospitals (13 university hospitals and 2 children's hospitals) since 2005, the prevalence of MRSA has gradually increased from less than 10% in the 1980s to 50%-70% in the 2000s, while the prevalence of ESBL-producing E. coli has increased from 30% in 2000 to 60% in 2012. The CTX-M genotype constituted 98.1% of the 158 strains of ESBL-producing E. coli being tested. 12 Enterobacteriaceae with decreased susceptibility to carbapenems were also observed in mainland China. Of the 49 Enterobacteriaceae isolates with decreased susceptibility to carbapenems collected from 2004 to 2008 in 16 teaching hospitals, CPE was noted in 33% (16/49) , Klebsiella pneumoniae carbapenemase (KPC-2) was found in six isolates, and imipenemase-4 (IMP-4) and imipenemase-8 (IMP-8) were identified in eight and two strains, respectively. 13 The dissemination of CTX-M and carbapenemase-type resistance involves both the expansion of successful clones and acquisition of resistance plasmids. Clonal expansion is the main mechanism for KPC dissemination, especially in healthcare settings. Qi et al reported that K. pneumoniae ST11 (a variant of the pandemic ST258 clone) was the dominant KPC-producing clone among 95 isolates from 15 hospitals in nine cities covering five provinces in China during 2006-2009. 14 In contrast, transmissible plasmids or transposons with integrons are the main vehicles through which the New Delhi metallo-b-lactamase (NDM) and IMP-type of genes spread in the community and hospitals. [15] [16] [17] [18] In China, self-transmissible IncX3 plasmids seem to be a common vehicle mediating the spread of NDM-1. IncX3 plasmids carrying NDM-1 have been detected in patients with epidemiological links to Guangzhou, Hunan, Haifeng and Dongguan 19 and have been reported to cause nosocomial outbreaks in a Beijing hospital. 20 IncX3 plasmids carrying NDM have also been reported from India and the United Arab Emirates. Of the .35 different IMP alleles, IMP-4 occurred most frequently among isolates from China, and the gene was often carried on broad hostrange plasmids, such as IncN and IncA/C groups, with the ability to shuttle into and out of Enterobacteriaceae, P. aeruginosa and A. baumannii. 17, 18, 21 Among non-glucose fermenters, the prevalence of carbapenem-resistant P. aeruginosa was found to be 29% in 2011. The proportion of CRAB also increased from 50% to 60% from 2009 to 2011, and OXA-23 was the most prevalent plasmid-encoded carbapenemase among CRAB isolates in China, which were found in 97.7% (216/221) of imipenem-resistant clinical isolates collected from 11 teaching hospitals. 22 Moreover, NDM-1-producing A. baumannii has recently been reported in four different provinces in mainland China. 22 MORTALITY RELATED TO MULTIDRUG-RESISTANT ORGANISMS Resistance against commonly used antibiotics in pathogens isolated from invasive infections is associated with increased morbidity and mortality. [23] [24] [25] In community-acquired infections, mortality from invasive pneumococcal pneumonia was significantly associated with penicillin minimum inhibitory concentrations of 4.0 mg/L or higher and cefotaxime minimum inhibitory concentration of 2.0 mg/L or higher, as shown in a cohort of 5837 ca