Carbapenem susceptibilities of Gram-negative pathogens in intra-abdominal and urinary tract infections: updated report of SMART 2015 in China

Hui Zhang,Yizhao Ni ,Haishen Kong,Wenxiang Huang,Huayin Li,Bingdong Gui,Ziyong Sun,Yunsong Yu,Xiaofeng Jiang,Weiping Wang,Anhua Wu,R Badal ,Kang Liao,Qiwen Yang,Chunxia Yang,Yong Wang,Shufang Zhang,Bin Shu ,Qiong Duan,Yingchun Xu

doi:10.1186/s12879-018-3405-1

Abstract

BackgroundTo evaluate the susceptibility rates of aerobic and facultative Gram-negative bacterial isolates from Chinese intra-abdominal infections (IAI) and urinary tract infections (UTI) focusing on carbapenems and comparing their effectiveness between 2014 and 2015.MethodsA total of 2318 strains in 2015 (1483 from IAI and 835 from UTI) and 2374 strains in 2014 (1438 from IAI and 936 from UTI) were included in the analysis. Antimicrobial susceptibilities were determined at a central laboratory using CLSI broth microdilution and interpretive standards. Hospital acquired (HA) IAI and UTI were defined as isolates sampled > 48 h and community acquired (CA) as isolates sampled < 48 h after admission.ResultsThe main species derived from IAI and UTI in 2015 were Escherichia coli (50.86%) and Klebsiella pneumoniae (19.20%). Susceptibilities of Escherichia coli IAI and UTI strains to imipenem (IPM) and ertapenem (ETP) were > 90% in 2014 and 2015, while the susceptibilities to IPM and ETP of Klebsiella pneumoniae IAI strains were > 80% in 2014 but dropped to ≤80% in 2015 for UTI strains. Susceptibilities of IAI Enterobacteriaceae strains to IPM and ETP in 2015 were lowest in the colon and abscesses, and Enterobacteriaceae susceptibilities of UTI and IAI isolates to IPM and ETP were lowest in medical, pediatric and surgery intensive care units (ICUs) in 2015.ConclusionsIPM and ETP were effective in vitro against Enterobacteriaceae isolated from IAIs and UTIs in 2014 and 2015, but susceptibility to carbapenems in UTIs markedly decreased in 2015.

Highlights

To evaluate the susceptibility rates of aerobic and facultative Gram-negative bacterial isolates from Chinese intra-abdominal infections (IAI) and urinary tract infections (UTI) focusing on carbapenems and comparing their effectiveness between 2014 and 2015
Asia has been reported to have the world’s highest incidence of ESBL-producing E. coli, K. pneumoniae, Klebsiella oxytoca and Proteus mirabilis strains from IAIs and UTIs in 2011, reaching 40% to 45% [2], and a number of recent publications have noted that cephalosporins and fluoroquinolones were not suitable antibiotics for the empirical treatment of IAI and UTI in China [3, 4], Zhang et al BMC Infectious Diseases (2018) 18:493 underlining the importance of monitoring susceptibilities to alternative antibiotics such as the carbapenems
In the present study we developed organ-specific weighted incidence antibiograms (OSWIAs) to estimate the likelihood of an isolate from a specific organ being susceptible to a given antibiotic

Summary

Introduction

To evaluate the susceptibility rates of aerobic and facultative Gram-negative bacterial isolates from Chinese intra-abdominal infections (IAI) and urinary tract infections (UTI) focusing on carbapenems and comparing their effectiveness between 2014 and 2015. In a previous Chinese study it was reported that the incidence of Extended-Spectrum β-Lactamases (ESBL)-producing. Asia has been reported to have the world’s highest incidence of ESBL-producing E. coli, K. pneumoniae, Klebsiella oxytoca and Proteus mirabilis strains from IAIs and UTIs in 2011, reaching 40% to 45% [2], and a number of recent publications have noted that cephalosporins and fluoroquinolones were not suitable antibiotics for the empirical treatment of IAI and UTI in China [3, 4], Zhang et al BMC Infectious Diseases (2018) 18:493 underlining the importance of monitoring susceptibilities to alternative antibiotics such as the carbapenems. IAI and UTI derived isolates and their susceptibilities to carbapenems, cephalosporins, fluoroquinolones, broad-spectrum penicillins combined with β-lactamase inhibitors, and an aminoglycoside were compared in different infected organs. The distribution of Enterobacteriaceae and non-Enterobacteriaceae infections isolated from HA and CA IAIs and UTIs in different age subgroups as well as the susceptibility patterns of major pathogens in different medical departments were analyzed

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Discussion

Conclusion