Loading...
  • antibiotic
  • There are also increasing reports of new modifications of the intrinsic ampicillin-resistance mechanism leading to resistance against cephalosporins and carbapenems, the last line of well-tolerated drugs, and ampicillin-resistant H. influenzae was included in the recently released priority list of antibiotic-resistant bacteria by the WHO. (microbiologyresearch.org)
  • It is concluded that genetic differences between the three clones investigated do influence their patterns of evolution, and may account for differences in their antibiotic resistance profiles. (qmul.ac.uk)
  • Direct transmission of antibiotic-resistant gonococci between individuals has been proposed as a driver for the increased transmission of resistance, but direct evidence of such transmission is limited. (bmj.com)
  • Conclusions These data support the transmission of antibiotic-resistant strains between sexual partners as a key driver of resistance rates in gonorrhoea among MSM. (bmj.com)
  • mechanism
  • Tipper DJ, Strominger JL (1965) Mechanism of action of penicillins: a proposal based on their structural similarity to acyl-D-alanyl-D-alanine. (springer.com)
  • Yocum RR, RasmussenJR SJL (1980) The mechanism of action of penicillin: penicillin acylates the active site of Bacillus stearothermophilus D-alanine carboxypeptidase. (springer.com)
  • One mechanism that has received particular attention is the requirement of RecA for minimally efficient processing segments (MEPS), which are short regions of sequence identity located at either end of the donor DNA strand and hypothesized to be required for recombination to occur ( 15 ). (sciencemag.org)
  • gene
  • Insertional inactivation of the gene ( mtrD ) encoding the membrane transporter component of the Mtr efflux pump in these transformant strains and in strain FA6140 decreased the MIC of penicillin by 16-fold. (asm.org)
  • PBP 2, encoded by the penA gene, has an approximately 10-fold higher affinity for penicillin than PBP 1 ( 7 ). (asm.org)
  • In previous reports, insertion of the Asp-345A codon into the penA gene has been proved to make a major contribution to the reduction of the affinity of gonococcal PBP 2 to penicillin ( 5 ). (asm.org)
  • As evidence, a mosaic pattern of fragments with high sequence divergence was detected in the chromosomal folP gene, the sulfonamide resistance determinant. (beds.ac.uk)
  • The impact of overexpression of the naturally occurring bla OXA-51-like gene remains to be determined, although recent data suggest its involvement in acquired resistance ( 12 ). (asm.org)
  • N. gonorrhoeae isolates with reduced susceptibility to extended-spectrum cephalosporins have been linked to altered penicillin-binding protein 2, encoded by the penA gene. (biomedcentral.com)
  • strains
  • In 2000 we isolated gonococcal strains with reduced susceptibilities to penicillin and cephems including cefixime, which is recommended as therapy for gonococcal urethritis, during an investigation into the cause of clinical failure in patients with gonococcal urethritis treated with oral cephems. (asm.org)
  • clinical
  • The prevalence of clinical PBP3-mediated resistance to ampicillin was 9%, compared to 2.5% three years earlier. (biomedcentral.com)
  • Perhaps the most fascinating part of the research is the description of how rapidly this clone has responded to massive in vivo interventions in the clinical environment, such as the introduction of penicillin and other antibiotics and more recently the introduction of conjugate anti-pneumococcal vaccines," says Tomasz. (bio-medicine.org)
  • divergence
  • Our findings suggest that the rate of recombination and its relation to genetic divergence have a strong influence on outcomes. (sciencemag.org)
  • Database analysis of multilocus sequence data from all three clones showed that recombination leads to sequence divergence more frequently than de novo mutation, but was significantly less common in England 14-9. (qmul.ac.uk)
  • amino acid
  • As penB represents amino acid substitutions within the third loop of the outer membrane PorIB protein that modulate entry of penicillin and tetracycline, the results presented herein suggest that PorIB and the MtrC-MtrD-MtrE efflux pump act synergistically to confer resistance to these antibiotics. (asm.org)
  • The T451A substitution was the key amino acid in PBP2b that contributed to penicillin resistance. (vanopijnenlab.com)
  • The amino acid substitutions in PBP1a, 2b, and 2x were the crucial factors for β-lactam resistance. (vanopijnenlab.com)
  • gonorrhoeae
  • We therefore aimed to systematically investigate the transmission of N. gonorrhoeae between men in sexual partnerships using WGS to compare isolates and their resistance to antibiotics at a genome level. (bmj.com)
  • fluoroquinolones
  • However, during the past few decades an increasing number of resistant Campylobacter isolates have developed resistance to fluoroquinolones and other antimicrobials such as macrolides, aminoglycosides, and beta-lactams. (hindawi.com)
  • strain
  • Curiously, penicillin and tetracycline resistance due to penB seems to be dependent on the presence of an mtrR mutation in the host strain ( 24 ). (asm.org)
  • In the early 1980s, an outbreak of gonorrhea occurred in the Durham, N.C., region that was caused by a strain (FA6140) for which the MICs of penicillin and tetracycline were both 4.0 μg/ml ( 9 ). (asm.org)
  • We show that in laboratory-derived mutants of Mycobacterium tuberculosis, rifampin resistance is universally associated with a competitive fitness cost and that this cost is determined by the specific resistance mutation and strain genetic background. (stanford.edu)
  • Three mosaic penA alleles were detected including two previously described alleles (XXXIV, XXXVIII) and one novel allele (LA-A). Of the 29 isolates with an alert value extended-spectrum cephalosporin MIC, all possessed the mosaic XXXIV penA allele and 18 were sequence type 1407, an internationally successful strain associated with multi-drug resistance. (biomedcentral.com)
  • affinity
  • This mutation reduces the binding affinity of PBP2 for penicillin, which results in decreased (fourfold) susceptibility of gonococci to penicillin ( 7 , 25 ). (asm.org)
  • novel
  • This study identified a novel class D β-lactamase involved in carbapenem resistance in A. baumannii . (asm.org)
  • alleles
  • At least some folP alleles conferring resistance have been horizontally acquired from other species, presumably from commensal Neisseriae . (beds.ac.uk)
  • protein
  • Marrec-Fairley M, Piette A, Gallet X et al (2000) Differential functionalities of amphiphilic peptide segments of the cell-septation penicillin-binding protein 3 of Escherichia coli . (springer.com)
  • events
  • The lengths of the unselected events were exponentially distributed with a mean of 2.3 kb, implying that recombinations are stochastically resolved with a fixed per base probability of 4.4×10(-4) bp(-1). (biomedsearch.com)
  • The recombinational events usually involve genetic exchange with streptococci of the mitis group and some pneumococci are thought to exhibit hyper-recombination. (frontiersin.org)