Two new assays for the detection of TEM-1 beta-lactamase-mediated bacterial penicillin resistance were developed that involve the use of specific nucleic acid hybridization. Both techniques are based on a solution-phase hybridization of oligonucleotide probes to the target DNA sequence, solid-phase capture of the probe-target complex, and an amplified chemiluminescent labeling method. One configuration of hybridization probes detected the presence of TEM-1 in Neisseria gonorrhoeae (45 strains), Haemophilus spp., Escherichia coli, Shigella sonnei and Salmonella typhi. A second configuration (TEM-1NH) detected TEM-1 beta-lactamase-mediated penicillin resistance only in N. gonorrhoeae (97 strains) and Haemophilus (6 strains) isolates in which TEM-1 is inserted in a pFA7-type plasmid. Both methods were 100 times more sensitive than a commercially available colorimetric beta-lactamase activity test and approximately 5 times more sensitive than radioisotopic dot blot screening for the gene. The assays are particularly well suited to the analysis of large numbers of samples, can be performed in a total of 4 h, and are sensitive to 10(4) to 10(5) CFU.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC266794 | PMC |
http://dx.doi.org/10.1128/jcm.26.10.1934-1938.1988 | DOI Listing |
Front Microbiol
April 2019
Department of Clinical Microbiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
TEM-1, mediated by plasmid and transposon, is the most commonly encountered β-lactamase in Gram-negative bacteria. Four different promoters upstream of -related genes have been identified: the weak promoter, and the strong promoters , , and In this study, we investigated the genetic basis of a clinical strain of (RJ904), which was found to be resistant to BLBLIs (β-lactam/β-lactamase inhibitors), including amoxicillin-clavulanate, ticarcillin-clavulanate (TCC), and piperacillin-tazobactam (TZP) but sensitive to third-generation cephalosporins. The conjugation test and S1-nuclease pulsed-field gel electrophoresis (S1-PFGE) demonstrated that transfer of this resistance was mediated by a ca.
View Article and Find Full Text PDFFront Mol Biosci
February 2018
Department of Pharmacology and Chemical Biology, Baylor College of Medicine, Houston, TX, United States.
The most common mechanism of resistance to β-lactam antibiotics in Gram-negative bacteria is the production of β-lactamases that hydrolyze the drugs. Class A β-lactamases are serine active-site hydrolases that include the common TEM, CTX-M, and KPC enzymes. The TEM enzymes readily hydrolyze penicillins and older cephalosporins.
View Article and Find Full Text PDFMedicine (Baltimore)
December 2017
Department of Microbiology and Immunology, School of Basic Medical Science, Xi'an Jiaotong University Health Science Center Key Laboratory of Environment and Genes Related to Diseases (Xi'an Jiaotong University), Ministry of Education Department of Laboratory Medicine Department of Hepatobiliary Surgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China.
Acinetobacter baumannii is one of the major threats in clinical infections due to its antibiotic resistance ability. It shows increasing resistance to carbapenems, mainly due to β-lactamase mediated mechanisms. The aim of this study was to investigate carbapenem resistance (CR) profiles and analyze β-lactamases genes composition of clinical A.
View Article and Find Full Text PDFAntimicrob Agents Chemother
December 2017
Entasis Therapeutics, Waltham, Massachusetts, USA
Sulbactam is one of four β-lactamase inhibitors in current clinical use to counteract drug resistance caused by degradation of β-lactam antibiotics by these bacterial enzymes. As a β-lactam itself, sulbactam is susceptible to degradation by β-lactamases. I investigated the Michaelis-Menten kinetics of sulbactam hydrolysis by 14 β-lactamases, representing clinically widespread groups within all four Ambler classes, i.
View Article and Find Full Text PDFJ Enzyme Inhib Med Chem
February 2017
a Department of Bioengineering , Marmara University, İstanbul , Turkey.
Declining efficiency of antibiotic-inhibitor combinatorial therapies in treating beta-lactamase mediated resistance necessitates novel inhibitor development. Allosteric inhibition offers an alternative to conventional drugs that target the conserved active site. Here, we show that the evolutionarily conserved PWP triad located at the N-terminus of the H10 helix directly interacts with the allosteric site in TEM-1 beta-lactamase and regulates its activity.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!