Emergence of carbapenem-resistant clinical Enterobacteriaceae isolates from a teaching hospital in Shanghai, China

Abstract

Carbapenems such as imipenem and meropenem are first-line agents for the treatment of serious nosocomial infections caused by multidrug-resistant clinical isolates of bacteria belonging to the family Enterobacteriaceae. However, resistance to carbapenems has increased dramatically among members of the family Enterobacteriaceae isolated from a teaching hospital in Shanghai, China. In the present study, we investigated the prevalence and molecular characteristics of carbapenemresistant clinical isolates of Enterobacteriaceae. None of the 77 clinical isolates collected from 2002 to 2009 were susceptible to ertapenem and only 6.5 % and 1.3 % of isolates were susceptible to imipenem and meropenem, respectively. Colistin and tigecycline were found to be the most active agents against carbapenem-resistant Enterobacteriaceae isolates, inhibiting 90 % of isolates at a concentration of 1 mg ml "1 and 4 mg ml , respectively. The results of PFGE analysis suggested that many of the KPC-2-producing isolates of Citrobacter freundii and Klebsiella pneumoniae were clonally related. Most of these isolates were isolated from the same ward, namely the neurosurgical ward, suggesting horizontal transfer of the KPC-2-encoding gene in these isolates. Of the 77 isolates, 84.4 % were found, by PCR, to be capable of carbapenemase production. SDS-PAGE analysis revealed that 75.3 % (58/77) of the isolates had lost at least one porin protein. Our results suggested that the prompt detection of carbapenemase-producing strains is critical for the containment of nosocomial transmission. As no novel antimicrobials have been identified for use in the treatment of these pan-drug-resistant isolates, further studies should focus on the rational use of available antibiotics, the implementation of active antibiotic resistance surveillance and the strict implementation of infection control measures to avoid the rapid spread or outbreak of carbapenemase-producing Enterobacteriaceae in health-care facilities. INTRODUCTIONCarbapenems such as imipenem and meropenem are firstline agents for the treatment of serious healthcare-associated infections caused by clinical multidrug-resistant Enterobacteriaceae (Brink et al., 2004). However, the phenomenon of carbapenem resistance is emerging in a wide variety of these species (Yigit et al., 2001). Carbapenemases have been widely detected in recent years and predominantly contribute to carbapenem resistance among members of the family Enterobacteriaceae including Klebsiella pneumoniae and Citrobacter freundii (Peleg & Hooper, 2010). Carbapenemases including KPC, VIM, IPM, SME and OXA belong to various families of b-lactamases (Queenan & Bush, 2007). Infections caused by carbapenem-resistant Enterobacteriaceae (CRE) have presented a great challenge to physicians in recent years (CDC, 2009;Munoz-Price & Quinn, 2009). In Shanghai, China, K. pneumoniae is the second most frequently isolated pathogen among Gram-negative bacilli according to the Shanghai Bacterial Resistance Surveillance Program (Zhu et al., 2006(Zhu et ...

Detection of the novel IMP-38 among carbapenemase-producing Enterobacteriaceae in a university hospital, China

“…A high prevalence rate of KPC-2 Enterobacteriaceae isolates has been reported in Zhejiang province, China, and sporadic reports have been made in Shanghai City, Jiangsu, and Jiangxi provinces [14][15][16]. In this study, four KPC-2-producing K. pneumoniae isolates with identical origination were detected.…”

Waging War Against Extended Spectrum Beta Lactamase and Metallobetalactamase Producing Pathogens- Novel Adjuvant Antimicrobial Agent Cse1034- An Extended Hope

“…BL+BLI (betalactamase and betalactamase inhibitor ally) are used for ESBL producing isolates, but carbapenems seemed to be the best options to treat patients with ESBL. Unfortunately, emergence of metallo-beta-lactamases restricted the use of carbapenems [2]. In India, the prevalence of MBLs range from 8% to 79% [3][4][5][6].…”

Outbreak of Klebsiella pneumoniae Carbapenemase-2-Producing K. pneumoniae Sequence Type 11 in Taiwan in 2011

“…Carbapenemases, however, are not the only mechanisms associated with resistance to carbapenems. For example, studies have shown that the combination of ESBL-AmpC hyperproduction with porin loss contributes to carbapenem nonsusceptibility (13,14,20,36,37).…”