The Quail Neuroretina clone 71 gene (QNR-71) is expressed during the differentiation of retinal pigmented epithelia and the epidermis. It encodes a type I transmembrane glycoprotein that shares significant sequence homologies with several melanosomal proteins. We have studied its intracellular traffic in both pigmented and non-pigmented cells. We report that a di-leucine-based sorting signal (E...

OBJECTIVES To analyse the prevalence of resistance to β-lactams and plasmid-mediated quinolone resistance in Enterobacteriaceae in the paediatric hospital of Uruguay. METHODS A total of 368 enterobacterial isolates collected between 1 May and 30 November 2009 were studied for the presence of extended-spectrum β-lactamases (ESBLs), qnr alleles and aac(6')Ib by phenotypic and molecular methods....

BACKGROUND Salmonella and Shigella cause significant morbidity and mortality among children worldwide. Increased antimicrobial resistance results in greater burden of disease. MATERIALS AND METHODS From 2005 to 2011, Salmonella and Shigella isolates collected from ill children at a major hospital in Yucatan, Mexico, were subjected to serotyping and antimicrobial susceptibility testing by disk...

Sir, Quinolone resistance in Enterobacteriaceae usually results from mutations in genes coding for chromosomally encoded type II topoisomerases, efflux pumps or porin-related proteins. Recently, transferable, plasmid-borne, quinolone resistance genes—qnrA, qnrB, qnrS, cr variant of aac(60)-Ib, qepA and oxqB—have been observed in clinical isolates, more frequently among strains producing plasmid...

The qnr genes are plasmid-borne fluoroquinolone-resistance determinants widespread in Enterobacteriaceae. Three families of qnr determinants (qnrA, B and S) have been described, but little is known about their expression and regulation. Two new determinants, qnrC and qnrD, have been found recently. Here, we describe the characterization of the qnrB2 promoter and the identification of a LexA-bin...

The Qnr proteins belong to the pentapeptide repeat protein family. Despite each pentapeptide repeat unit being an important structural determinant, accurately determining pentapeptide repeat units in the Qnr proteins through sequence-based alignments has been challenging. In the present study, the pentapeptide repeat units of the nine representative Qnr proteins have been precisely determined v...

We found two NADH-dependent reductases (QNR and bacC) in Microbacterium luteolum JCM 9174 (M. luteolum JCM 9174) that can reduce 3-quinuclidinone to optically pure (R)-(-)-3-quinuclidinol. Alcohol dehydrogenase from Leifsonia sp. (LSADH) was combined with these reductases to regenerate NAD+ to NADH in situ in the presence of 2-propanol as a hydrogen donor. The reductase and LSADH genes were eff...

BACKGROUND Plasmid-mediated quinolone resistance is an increasing clinical concern, globally. The major objective of the present study was to identify the qnr-encoding genes among the quinolone non-susceptible K. pneumoniae isolates obtained from two provinces in Iran. METHODS A total of 200 K. pneumoniae isolates were obtained from hospitals of Qazvin and Tehran, Iran. The identification of ...

BACKGROUND Escherichia coli is an important bacterial species based on incidence and associated infection severity. Some E. coli strains produce extended-spectrum beta lactamase (ESBL) and are called ESBL-producing E. coli. These strains are resistant to most classes of cephalosporin and a number of other classes of antibiotics. Plasmids carrying qnr genes have been found to transmit quinolone ...

INTRODUCTION Plasmid-mediated quinolone resistance, which complicates treatment, has been increasingly identified in Escherichia coli isolates worldwide. The purpose of this study was to identify the plasmid-mediated qnrA and qnrB genes among the quinolone-resistant Escherichia coli isolated from urinary tract infections in Iran. METHODOLOGY A total of 140 Escherichia coli isolates were colle...