A study was designed to describe the molecular epidemiology of CTX-M-producing Escherichia coli over a 6-year period (2000 to 2005) in a large well-defined Canadian region with a centralized laboratory system. Molecular characterization was done by isoelectric focusing, PCR, and automated sequencing, while genetic relatedness was determined by pulsed-field gel electrophoresis with XbaI. Of the ...

OBJECTIVES To characterize a novel CTX-M chimera, CTX-M-137, from Escherichia coli clinical isolates in China. METHODS Isolates were collected from five hospitals between 22 February 2009 and 20 December 2011. Resistance genes were investigated by PCR. blaCTX-M-137 was cloned and purified for kinetic measurements. Conjugation experiments, S1-PFGE and Southern blotting were performed to study ...

INTRODUCTION Despite declining risk of vertical HIV transmission, prophylactic cotrimoxazole (CTX) remains widely used to reduce morbidity and mortality in the event of HIV infection among exposed infants, with an inherent risk of conferring commensal antimicrobial resistance. Using data from a randomized, placebo-controlled trial of infant CTX prophylaxis, we sought to quantify emergence of an...

Resistance of mouse M5076 (M5) ovarian reticular cell sarcoma to cyclophosphamide (CTX) was obtained in vivo by repeated drug treatment followed by transplantation of the regrowing tumor. After 16 passages, we obtained an M5 subline resistant to CTX (M5-CTX-16R). Median survival times were approximately 29 and 39 days for M5 and M5-CTX-16R, respectively. Survival of M5-bearing mice given a sing...

The conotoxin-like (ctx) gene encodes a small cysteine-rich polypeptide in various baculoviruses. Previous research has demonstrated that the product of the ctx gene could be purified from insect cells infected by Autographa californica nuclear polyhedrosis virus (AcMNPV), but its function was unknown. In this paper, we compared the conserved cysteine motif structure (CX3GX2CX5CCX3CX6C) of the ...

Background: A novel drug delivery system using poly (ε-caprolactone) - poly (ethylene glycol) -poly (ε-caprolactone) (PCL-PEG-PCL) was established in this study. Methods: Ceftriaxone (CTX) was encapsulated within PCL-PEG-PCL nanoparticles by a double emulsion technique (w/o/w), leading to creation of ceftriaxone-loaded PCL-PEG-PCL (CTX/PCL-PEG-PCL) polymersomes. The resulting polymersomes...

The main aim of this study was to understand the relationship between the drug-resistant characteristics of Klebsiella pneumoniae and CTX-M-type extended spectrum β-lactamases (ESBLs), and to detect the distributions of CTX-M-type ESBLs in clinically isolated strains. CTX-M ESBL genes isolated from the clinical samples were amplified by polymerase chain reaction and identified by sequence analy...

The detection rate of CTX-M-type β-lactamase-producing Enterobacteriaceae in Japan has significantly increased. Nursing homes may be a reservoir of antibiotic-resistant bacteria. Therefore, we determined the prevalence of, and risk factors associated with, fecal carriage of CTX-M-type β-lactamase-producing Enterobacteriaceae among nursing home residents. A total of 225 stool samples were collec...

A variety of CTX-M-type extended-spectrum β-lactamases (ESBLs), including hybrid ones, have been reported in China that are uncommon elsewhere. To better characterize the substrate profiles and enzymatic mechanisms of these enzymes, we performed comparative kinetic analyses of both parental and hybrid CTX-M enzymes, including CTX-M-15, -132, -123, -64, -14 and -55, that are known to confer vari...