A5028041493- Antibiotic Resistance in Bacteria
- Antibiotics Pharmacokinetics and Efficacy
- Bacterial biofilms and quorum sensing
- Pharmaceutical and Antibiotic Environmental Impacts
- Bacterial Genetics and Biotechnology
- Antibiotic Use and Resistance
- Pneumonia and Respiratory Infections
- Bacteriophages and microbial interactions
- Vibrio bacteria research studies
- Cancer therapeutics and mechanisms
- Enterobacteriaceae and Cronobacter Research
- Antimicrobial Resistance in Staphylococcus
- Plant Pathogenic Bacteria Studies
- Bacterial Identification and Susceptibility Testing
- RNA and protein synthesis mechanisms
- Pneumocystis jirovecii pneumonia detection and treatment
- Infections and bacterial resistance
- Escherichia coli research studies
- Microbial Natural Products and Biosynthesis
- Amino Acid Enzymes and Metabolism
- Biochemical effects in animals
- Salmonella and Campylobacter epidemiology
- Genomics and Phylogenetic Studies
- Mycobacterium research and diagnosis
- Essential Oils and Antimicrobial Activity
Lahey Medical Center
2013-2022
Lahey Hospital and Medical Center
2007-2017
Harvard University
1969-2017
Massachusetts General Hospital
1989-2011
Albert Einstein College of Medicine
2008
Edith Nourse Rogers Memorial Veterans Hospital
1997-2004
Deaconess Hospital
1990-1991
Miriam Hospital
1986-1990
Institut Pasteur
1989
Boston University
1972-1988
Among 313 Enterobacteriaceae from the United States with a ciprofloxacin MIC of >/=0.25 microg/ml and reduced susceptibility to ceftazidime, aac(6')-Ib was present in 50.5% isolates, these, 28% carried cr variant responsible for low-level resistance. aac(6')-Ib-cr geographically widespread, stable over time, most common Escherichia coli, equally prevalent ciprofloxacin-susceptible -resistant strains, not associated qnr genes.
Quinolones are potent antibacterial agents that specifically target bacterial DNA gyrase and topoisomerase IV. Widespread use of these has contributed to the rise quinolone resistance. Previous studies have shown resistance arises by mutations in chromosomal genes. Recently, a multiresistance plasmid was discovered encodes transferable quinolones. We cloned plasmid-quinolone gene, termed qnr, found it an integron-like environment upstream from qacE Δ 1 sulI . The gene product Qnr 218-aa...
We screened 313 ceftazidime-resistant Enterobacteriaceae isolates obtained in the United States from 1999 to 2004 for all three known qnr genes. A gene was present 20% of Klebsiella pneumoniae isolates, 31% Enterobacter sp. and 4% Escherichia coli isolates. qnrA qnrB occurred with equivalent frequencies and, except enterobacters, were stable over time. qnrS absent.
Although quinolone resistance usually results from chromosomal mutations, recent studies indicate that can also be plasmid mediated. The gene responsible, qnr, is distinct the known genes and in previous seemed to restricted Klebsiella pneumoniae Escherichia coli isolates University of Alabama Birmingham, where this was discovered. In Shanghai, frequency ciprofloxacin E. has exceeded 50% since 1993. Seventy-eight unique ciprofloxacin-resistant clinical Shanghai hospitals were screened for...
A novel plasmid-mediated quinolone resistance gene, qnrB, has been discovered in a plasmid encoding the CTX-M-15 beta-lactamase from Klebsiella pneumoniae strain isolated South India. It less than 40% amino acid identity with original qnr (now qnrA) gene or recently described qnrS but, like them, codes for protein belonging to pentapeptide repeat family. Strains qnrB demonstrated low-level all quinolones tested. The cloned an expression vector attaching polyhistidine tag, which facilitated...
During a 4-month period in late 1988, we isolated ceftazidime-resistant strains of Klebsiella pneumoniae and other members the family Enterobacteriaceae from 29 patients at chronic-care facility Massachusetts. Ceftazidime resistance resulted two distinct extended-spectrum beta-lactamases TEM type which efficiently hydrolyzed cephalosporin: YOU-1 with pI 5.57 YOU-2 5.2. Genes encoding these enzymes were present on different but closely related high-molecular-weight, multiple antibiotic...
Recently, several plasmid-mediated quinolone resistance (PMQR) genes conferring low levels of have been discovered. To evaluate the temporal change in prevalence PMQR over a decade tertiary hospital Republic Korea, we selected every fifth isolate Escherichia coli and Klebsiella pneumoniae third Enterobacter cloacae between 1998 2001 2005 2006 from collection blood isolates. Six [qnrA, qnrB, qnrC, qnrS, aac(6')-Ib-cr, qepA] were screened by multiplex PCR then confirmed direct sequencing,...
Klebsiella pneumoniae isolates from 11 patients at the Miriam Hospital were identified as resistant to cefoxitin and ceftibuten well aztreonam, cefotaxime, ceftazidime. Resistance could be transferred by conjugation or transformation with plasmid DNA into Escherichia coli was due production of a beta-lactamase an isoelectric point 8.4 named MIR-1. In E. coli, MIR-1 conferred resistance ceftazidime, ceftibuten, ceftriaxone, such alpha-methoxy beta-lactams cefmetazole, cefotetan, cefoxitin,...