23 We characterized carbapenem resistance mechanisms among 12 Klebsiella 24 pneumoniae carbapenemase-producing K. pneumoniae (KPC-Kp) clinical isolates, and 25 evaluated their effects on the activity of 2and 3-drug combinations of colistin, 26 doripenem and ertapenem. All isolates were resistant to ertapenem and doripenem; 27 75% (9/12) were resistant to colistin. Isolates belonged to ST258 clo...

Carbapenem-resistant Enterobacteriaceae (CRE) has increasingly spread worldwide in the past decade. The prevalence and characteristics of CRE in Thailand are unknown. In this study, we conducted a 2-year surveillance of CRE among 12,741 clinical isolates of Enterobacteriaceae at the largest university hospital in Thailand with molecular characterization of beta-lactamase (bla) genes, including ...

Phagocytosis is a key process of the immune system. The human pathogen Klebsiella pneumoniae is a well known example of a pathogen highly resistant to phagocytosis. A wealth of evidence demonstrates that the capsule polysaccharide (CPS) plays a crucial role in resistance to phagocytosis. The amoeba Dictyostelium discoideum shares with mammalian macrophages the ability to phagocytose and kill ba...

We investigated the occurrence and genetic basis of AmpC β-lactamase (AmpC)-mediated antibiotic resistance, by examining Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis isolates at a university hospital, from 2007 to 2010. The ampC genes were detected by multiplex AmpC PCR, and AmpC-positive strains were subjected to DNA sequencing. Extended-spectrum β-lactamase (ESBL) production...

A Klebsiella pneumoniae isolate showing moderate to high-level imipenem and meropenem resistance was investigated. The MICs of both drugs were 16 microg/ml. The beta-lactamase activity against imipenem and meropenem was inhibited in the presence of clavulanic acid. The strain was also resistant to extended-spectrum cephalosporins and aztreonam. Isoelectric focusing studies demonstrated three be...

Despite worldwide dissemination of New Delhi metallo-β-lactamase1 (blaNDM-1), outbreaks remain uncommon in China. In this study, we describe the characteristics of the outbreak-related blaNDM-1-producing K. pneumonia isolates in a neonatal unit in Shandong province, China. We recovered 21 non-repetitive carbapenem-resistant K. pneumoniae isolates with a positively modified Hodge test (MHT) or E...

Susceptibility results with low reproducibility by the same or different methods have been observed for metallo-beta-lactamase (MBL)-producing Enterobacteriaceae. Eighteen VIM-1-producing Klebsiella pneumoniae isolates (one per patient) belonging to a single epidemic clone in our hospital (2005 to 2008) but with different susceptibilities to carbapenems were studied. Imipenem MICs ranged from 8...

We characterized carbapenem resistance mechanisms among 12 Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae (referred to here as KPC K. pneumoniae) clinical isolates and evaluated their effects on the activity of 2- and 3-drug combinations of colistin, doripenem, and ertapenem. All isolates were resistant to ertapenem and doripenem; 75% (9/12) were resistant to colistin. Isolat...

OBJECTIVES The aim of this study was to investigate relatedness and molecular mechanism(s) of ertapenem resistance in clinical isolates of Klebsiella spp. (n = 28) and Enterobacter spp. (n = 27) referred from multiple hospitals to the UK national reference laboratory. METHODS Investigations included genotyping by PFGE, resistance gene analysis by PCR and antimicrobial susceptibility testing w...

We measured in vitro activity of plazomicin, a next-generation aminoglycoside, and other aminoglycosides against 50 carbapenem-resistant Klebsiella pneumoniae strains from two centers and correlated the results with the presence of various aminoglycoside-modifying enzymes (AMEs). Ninety-four percent of strains were sequence type 258 (ST258) clones, which exhibited 5 ompK36 genotypes; 80% and 10...