Introduction: Extended spectrum β-lactamases (ESBLs) are enzymes that degrade β-lactam antibiotics and have been reported to be an important cause of nosocomial infection in worldwide. Methods: During 2009, 659 enterobacteria strains were isolated from different clinical specimens and tested for ESBL production. The disk approximation test, combined disk method and addition of clavulanic acid w...

A new method for multilocus enzyme electrophoresis, based on electrophoretic transfers to nitrocellulose after polyacrylamide-agarose gel electrophoresis was explored. Electrophoretic separation was performed on 1-mm-thick slab gels with 6-mul samples of bacterial extracts and was followed by serial 5-min consecutive transfers. The transferability of 19 metabolic enzymes of Klebsiella strains w...

The capsular polysaccharide (CPS) plays important role in Klebsiella spp pathogenesis. Capsular types K1 and K2 of Klebsiella pneumoniae are considered most virulent for humans. The capsule biosynthesis region flanking genes galF and gnd from clinical isolates and reference strains of K. pneumoniae were screened for polymorphism. Nucleotide sequence analysis of galF and gnd revealed a high hete...

BACKGROUND Extended-spectrum β-lactamases (ESBLs) is one of the most important mechanisms of resistance to β-lactams especially among Enterobacteriaceae family including Klebsiella spp. Different types of extended-spectrum β-lactamases including CTX-M-type and PER enzymes are identified among gram negative bacteria. OBJECTIVES The current study aimed to determine the prevalence of CTX-M-type ...

To investigate the occurrence of different Klebsiella spp. in aquatic environments, a total of 208 samples of natural surface waters was examined. From half (53%) of these samples, 123 Klebsiella strains were isolated, the most common species being Klebsiella pneumoniae. A comparison of these isolates to a group of 207 clinical K. pneumoniae isolates demonstrated that water isolates of K. pneum...

Cefatrizine, a new orally administered cephalosporin, was tested against 400 clinical isolates. Cefatrizine had excellent activity against gram-positive cocci, inhibiting all except enterococci at minimal inhibitory concentrations below 1 mug/ml. Cefatrizine inhibited the majority of Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, and Salmonella at concentrations below 12.5 mug/ml. ...

A new phosphonopeptide, alafosfalin, was evaluated for in vitro antibacterial activity and for synergism with /3-lactams, using 475 Japanese clinical isolates from urinary tract infections. Alafosfalin was found to be highly active against Escherichia coli and moderately active against Serratia, Klebsiella, Enterobacter, and Citrobacter, but less active against gram-positive organisms than were...

Vaborbactam (formerly RPX7009) is a new β-lactamase inhibitor based on a cyclic boronic acid pharmacophore with potent inhibitory activity against Klebsiella pneumoniaecarbapenemases (KPC). It has been developed in combination with meropenem. The objective of these studies was to identify the concentrations of both agents associated with the selection or prevention of single-step mutations lead...

A "high risk" clone of carbapenem-resistant Klebsiella pneumoniae (CRKP) identified by multilocus sequence typing (MLST) as sequence type (ST) 258 has disseminated worldwide. As the molecular epidemiology of the CRE pandemic continues to evolve, the clinical impact of non-ST258 strains is less well defined. We conducted an epidemiological investigation of CRKP based on strains MLST. Among 68 CR...

Multiplex-PCR assay for identification of Klebsiella pneumoniae isolates carrying gene clusters for biosynthesis of capsular polysaccharide (CPS) types K1 and K2 was developed. Genes wzc and orf10 of the cps cluster were applied as K1 and K2 specific markers respectively. The assay specificity was confirmed using 147 isolates of Klebsiella spp. including 77 K-antigen reference strains. The mult...