Kang LİAO, Yili CHEN, Han HUANG, Penghao GUO, Dongmei CHEN, Min LİU, Yan ZENG

Molecular characteristics of carbapenem-resistant Enterobacteriaceae isolates from a Chinese Tertiary Hospital

ET Amaç: Bu çalışmada Çin’in Guangdong bölgesinde bulunan bir eğitim hastanesinde, Ocak 2008 ile Aralık 2011 tarihleri arasında dönemde izole edilen karbapenem dirençli Enterobacteriaceae (CRE), kökenlerinin moleküler özelliklerini incelemesi amaçlanmıştır.Yöntemler: Çalışma döneminde 3286 suştan toplam 28 (% 0,9) CRE izolatı ayrıştırıldı ve çalışmaya alındı. Antimikrobiyal duyarlılık testleri, Modifiye Hodge (MHT) testi ve genotip incelenmesinde Pulsed-field jel elektroforez kullanıldı. Genişletilmiş spektrumlu β-laktamaz (GSBL) ve karbapenemaz genlerinin varlığı, gen amplifikasyonu ve dizi analizi kullanılarak tespit edildi. Bakterilerin Dış zar porini (OMP) genleri (OmpK35 / OmpK36 K. pneumoniae, E. cloacae için OMPC / OmpF) incelendi.Bulgular: MHT ile 28 kökenin yedisi (% 25,0) dirençli Enterobacteriaceae olarak tanımlandı. PCR ve dizi analizi gibi moleküler yöntemlerle kökenlerden 15’inin (% 53,6) GSBL pozitif olduğu, altısının AmpC (% 21,4), beşinin IMP-4 (% 17,9) ve dokuzunun en az iki farklı sınıf dirence sahip olduğu görülmüştür. Özel olarak, yedi MHT pozitif kökenin beşinin (% 71,4) karbapenemaz kodlayan genlerinin IMP-4 üretimine bağlı iken PFGE analizinde bir K. pneumoniae dışında hemen hemen tüm CRE kökenlerinin, OMPC ve / veya ompF içinde OmpK35 ve / veya OmpK36 kaybı gen ifade kaybı gözlendi. PFGE analizi genomik değişkenlik gösterdi.Sonuç: Enterobacteriaceae karbapenem direnci bu organizmalarda gözlenen OMP’lerin kayb sonucu oluşan porin’e değişimi ve β-laktamazların kombine etkisi nedeniyle oluşmaktadır. CRE yayılımı ve enfeksiyonlar hem anlamlı acil halk sağlığı hedefleri haline gelmiştir önlemek için

Anahtar Kelimeler:

Moleküler özellikler, karbapenem dirençli, Enterobacteriaceae, IMP-4

Molecular characteristics of carbapenem-resistant Enterobacteriaceae isolates from a Chinese Tertiary Hospital

Objective: The aim of this study was to investigate the molecular characteristics of carbapenem-resistant Enterobacteriaceae (CRE) isolates from a teaching hospital in Guangdong, China, during the period between January 2008 and December 2011. Methods: A total of 28 (0.9%) CRE isolates were collected among 3286 isolates. Antimicrobial susceptibility testing, Modified Hodge Test (MHT) and genotyping by pulsed-field gel electrophoresis were performed. Extended-spectrum β-lactamase (ESBL) and carbapenemase genes were detected using gene amplification and sequencing. Outer membrane porin (OMP) genes (OmpK35/OmpK36 for K. pneumoniae, OmpC/OmpF for E. cloacae were examined. Results: Seven (25.0%) isolates of the 28 carbapenem resistant Enterobacteriaceae had a positive MHT. PCR and sequencing analysis revealed that 19 of the 28 isolates were molecularly confirmed to harbor ESBLs (15 isolates, 53.6%), AmpC (6 isolates, 21.4%), or IMP-4 (five isolates, 17.9%), and nine (32.1%) isolates of the 28 isolates possessed at least two different classes of β-lactamases. Specially, five (71.4%) of seven MHT-positive CRE isolates is due to the production of the carbapenemase-encoding gene IMP-4. Almost all of the CRE isolates in the present study loss gene expressions of OmpK35 and/or OmpK36 in K. pneumoniae, OmpC and/or OmpF in E. cloacae, except for one K. pneumoniae. PFGE analysis demonstrated genomic variability. Conclusion: Carbapenem resistance in Enterobacteriaceae is due to the combined effect of β- lactamases with porin impermeability caused by loss of OMPs observed in these organisms. To prevent both CRE transmission and infections has become significantly urgent public health objectives.

Keywords:

Molecular characteristics, Carbapenem-resistant, Enterobacteriaceae, IMP-4.,

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Brink AJ, Feldman C, Grolman DC, et al. Appropriate use of the carbapenems. S Afr Med J 2004; 94:857-861.
Rhomberg P R, Jones R N. Summary trends for the Me- ropenem Yearly Susceptibility Test Information Collection Program: a 10-year experience in the United States (1999- 2008). Diagn Microbiol Infect Dis 2009; 65:414-426.
Hidron AI, Edwards JR, Patel J, et al. NHSN annual update: antimicrobial-resistant pathogens associated with health- care-associated infections: annual summary of data reported to the National Healthcare Safety Network at the Centers for Disease Control and Prevention, 2006-2007. Infect Control Hosp Epidemiol 2008; 29:996-1011.
Livermore DM, Woodford N. The beta-lactamase threat in En- terobacteriaceae, Pseudomonas and Acinetobacter. Trends Microbiol 2006; 14:413-420.
Nordmann P, Naas T, Poirel L. Global spread of Carbapene- mase-producing Enterobacteriaceae. Emerg Infect Dis 2011; 17:1791-1798.
Doumith M, Ellington M J, Livermore D M, et al. Molecular mechanisms disrupting porin expression in ertapenem-resis- tant Klebsiella and Enterobacter spp. clinical isolates from the UK. J Antimicrob Chemother 2009; 63:659-667.
Kim S Y, Park Y J, Yu J K, et al. Prevalence and mechanisms of decreased susceptibility to carbapenems in Klebsiella pneu- moniae isolates. Diagn Microbiol Infect Dis 2007; 57:85-91.
Wang X D, Cai J C, Zhou H W, et al. Reduced susceptibility to carbapenems in Klebsiella pneumoniae clinical isolates associated with plasmid-mediated beta-lactamase produc- tion and OmpK36 porin deficiency. J Med Microbiol 2009; 58:1196-1202.
Cai J C, Zhou H W, Zhang R, et al. Emergence of Serratia marcescens, Klebsiella pneumoniae, and Escherichia coli Isolates possessing the plasmid-mediated carbapenem- hydrolyzing beta-lactamase KPC-2 in intensive care units of a Chinese hospital. Antimicrob Agents Chemother 2008; 52:2014-2018.
Yu F, Ying Q, Chen C, et al. Outbreak of pulmonary infec- tion caused by Klebsiella pneumoniae isolates harbouring blaIMP-4 and blaDHA-1 in a neonatal intensive care unit in China. J Med Microbiol 2012; 61:984-989.
Wei Z, Yu T, Qi Y, et al. Coexistence of plasmid-mediated KPC-2 and IMP-4 carbapenemases in isolates of Kleb- siella pneumoniae from China. J Antimicrob Chemother 2011;66:2670-2671.
Yan J J, Ko W C, Wu H M, et al. Complexity of Klebsiella pneumoniae isolates resistant to both cephamycins and extended-spectrum cephalosporins at a teaching hospital in Taiwan. J Clin Microbiol 2004;42:5337-5340.
Yigit H, Queenan A M, Anderson G J, et al. Novel carbape- nem-hydrolyzing beta-lactamase, KPC-1, from a carbape- nem-resistant strain of Klebsiella pneumoniae. Antimicrob Agents Chemother 2001;45:1151-1161.
Queenan A M, Bush K. Carbapenemases: the versatile beta- lactamases. Clin Microbiol Rev 2007; 20:440-458.
Poirel L, Benouda A, Hays C, et al. Emergence of NDM- 1-producing Klebsiella pneumoniae in Morocco. J Antimicrob Chemother 2011;66:2781-2783.
Dai W, Sun S, Yang P, et al. Characterization of carbapen- emases, extended spectrum beta-lactamases and molecular epidemiology of carbapenem-non-susceptible Enterobacter cloacae in a Chinese hospital in Chongqing]. Infect Genet Evol 2013; 14:1-7.
Hidron A I, Edwards J R, Patel J, et al. NHSN annual update: antimicrobial-resistant pathogens associated with health- care-associated infections: annual summary of data reported to the National Healthcare Safety Network at the Centers for Disease Control and Prevention, 2006-2007. Infect Control Hosp Epidemiol 2008; 29:996-1011.
Patel G, Huprikar S, Factor S H, et al. Outcomes of carbape- nem-resistant Klebsiella pneumoniae infection and the im- pact of antimicrobial and adjunctive therapies. Infect Control Hosp Epidemiol 2008;29:1099-1106.
Gupta N, Limbago B M, Patel J B, et al. Carbapenem-resis- tant Enterobacteriaceae: epidemiology and prevention. Clin Infect Dis 2011;53:60-67.
Hirsch E B, Tam V H. Detection and treatment options for Klebsiella pneumoniae carbapenemases (KPCs): an emerg- ing cause of multidrug-resistant infection. J Antimicrob Che- mother 2010;65:1119-1125.
Balm M N, Ngan G, Jureen R, et al. Molecular characteriza- tion of newly emerged blaKPC-2-producing Klebsiella pneu- moniae in Singapore. J Clin Microbiol 2012;50:475-476.
Hu F, Chen S, Xu X, et al. Emergence of carbapenem-resis- tant clinical Enterobacteriaceae isolates from a teaching hos- pital in Shanghai, China. J Med Microbiol 2012;61:132-136.
Nordmann P, Poirel L, Carrer A, et al. How to detect NDM-1 producers. J Clin Microbiol 2011;49:718-721.
Cornaglia G, Giamarellou H, Rossolini G M. Metallo-beta- lactamases: a last frontier for beta-lactams? Lancet Infect Dis 2011;11:381-393.
Yan J J, Ko W C, Chuang C L, et al. Metallo-beta-lactamase- producing Enterobacteriaceae isolates in a university hospi- tal in Taiwan: prevalence of IMP-8 in Enterobacter cloacae and first identification of VIM-2 in Citrobacter freundii. J Anti- microb Chemother 2002;50:503-511.
Kumarasamy K K, Toleman M A, Walsh T R, et al. Emer- gence of a new antibiotic resistance mechanism in India, Pakistan, and the UK: a molecular, biological, and epidemio- logical study. Lancet Infect Dis 2010;10:597-602.
Rolain J M, Parola P, Cornaglia G. New Delhi metallo-beta- lactamase (NDM-1): towards a new pandemia? Clin Micro- biol Infect 2010;16:1699-1701.
Doumith M, Ellington M J, Livermore D M, et al. Molecular mechanisms disrupting porin expression in ertapenem-resis- tant Klebsiella and Enterobacter spp. clinical isolates from the UK. J Antimicrob Chemother 2009;63:659-667.