scholarly journals Multiply resistant viridans streptococci: susceptibility to beta-lactam antibiotics and comparison of penicillin-binding protein patterns.

1983 ◽  
Vol 24 (5) ◽  
pp. 702-705 ◽  
Author(s):  
B F Farber ◽  
G M Eliopoulos ◽  
J I Ward ◽  
K L Ruoff ◽  
V Syriopoulou ◽  
...  
Keyword(s):  
Binding Protein ◽  
Penicillin Binding Protein ◽  
Beta Lactam ◽  
Viridans Streptococci ◽  
Protein Patterns ◽  
Beta Lactam Antibiotics

scholarly journals Insight into the Diversity of Penicillin-Binding Protein 2x Alleles and Mutations in Viridans Streptococci

2017 ◽  
Vol 61 (5) ◽  
Author(s):  
Mark van der Linden ◽  
Julia Otten ◽  
Carina Bergmann ◽  
Cristina Latorre ◽  
Josefina Liñares ◽  
...  
Keyword(s):  
Binding Protein ◽  
Penicillin Binding Protein ◽  
Beta Lactam ◽  
Viridans Streptococci ◽  
Content Type ◽  
The Family ◽  
Biological Tests ◽  
Resistant Strains ◽  
National Reference Center ◽  
Partner Proteins

ABSTRACT The identification of commensal streptococci species is an everlasting problem due to their ability to genetically transform. A new challenge in this respect is the recent description of Streptococcus pseudopneumoniae as a new species, which was distinguished from closely related pathogenic S. pneumoniae and commensal S. mitis by a variety of physiological and molecular biological tests. Forty-one atypical S. pneumoniae isolates have been collected at the German National Reference Center for Streptococci (GNRCS). Multilocus sequence typing (MLST) confirmed 35 isolates as the species S. pseudopneumoniae. A comparison with the pbp2x sequences from 120 commensal streptococci isolated from different continents revealed that pbp2x is distinct among penicillin-susceptible S. pseudopneumoniae isolates. Four penicillin-binding protein x (PBPx) alleles of penicillin-sensitive S. mitis account for most of the diverse sequence blocks in resistant S. pseudopneumoniae, S. pneumoniae, and S. mitis, and S. infantis and S. oralis sequences were found in S. pneumoniae from Japan. PBP2x genes of the family of mosaic genes related to pbp2x in the S. pneumoniae clone Spain23F-1 were observed in S. oralis and S. infantis as well, confirming its global distribution. Thirty-eight sites were altered within the PBP2x transpeptidase domains of penicillin-resistant strains, excluding another 37 sites present in the reference genes of sensitive strains. Specific mutational patterns were detected depending on the parental sequence blocks, in agreement with distinct mutational pathways during the development of beta-lactam resistance. The majority of the mutations clustered around the active site, whereas others are likely to affect stability or interactions with the C-terminal domain or partner proteins.

scholarly journals Penicillin-binding protein 2x of Streptococcus pneumoniae: enzymic activities and interactions with β-lactams

1993 ◽  
Vol 292 (3) ◽  
pp. 735-741 ◽  
Author(s):  
M Jamin ◽  
C Damblon ◽  
S Millier ◽  
R Hakenbeck ◽  
J M Frère
Keyword(s):  
Streptococcus Pneumoniae ◽  
Extracellular Enzymes ◽  
Binding Protein ◽  
Soluble Form ◽  
Penicillin Binding Protein ◽  
Beta Lactam ◽  
Easy Method ◽  
Beta Lactam Antibiotics ◽  
Catalytic Behaviour ◽  
First Time

The high-molecular-mass penicillin-binding protein (PBP) 2x, one of the primary targets of beta-lactam antibiotics in Streptococcus pneumoniae, has been produced as a soluble form and purified in large amounts. It has been shown to catalyse hydrolysis and transfer reactions with different ester and thiolester substrates and its catalytic behaviour was often similar to that of the soluble DD-peptidase from Streptomyces R61. This provided an easy method to monitor the activity of the PBP. For the first time, a reliable kinetic study of the interaction between a lethal target and beta-lactam antibiotics has been performed. Characteristic kinetic parameters were obtained with different beta-lactam compounds. These results not only validated the mechanism established with non-essential extracellular enzymes, but will also constitute the basis for comparative studies of the low-affinity variants from penicillin-resistant strains.

scholarly journals Susceptibility to beta-lactam antibiotics of Pseudomonas aeruginosa overproducing penicillin-binding protein 3.

1997 ◽  
Vol 41 (5) ◽  
pp. 1158-1161 ◽  
Author(s):  
X Liao ◽  
R E Hancock
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Binding Protein ◽  
Broad Host Range ◽  
Penicillin Binding Protein ◽  
Beta Lactam ◽  
Beta Lactams ◽  
E Coli ◽  
Beta Lactam Antibiotics ◽  
Range Vector ◽  
Cell Inhibition

By using a broad-host-range vector, pUCP27, the Pseudomonas aeruginosa and Escherichia coli pbpB genes, which encode penicillin-binding protein 3 (PBP3), were separately overexpressed in a P. aeruginosa strain, PAO4089, that is deficient in producing chromosomal beta-lactamase. Susceptibility studies indicated that overproduction of the P. aeruginosa PBP3 in PAO4089 resulted in twofold-increased resistance to aztreonam, fourfold-increased resistance to cefepime and cefsulodin, and eightfold-increased resistance to ceftazidime, whereas overproduction of the P. aeruginosa PBP3 in PAO4089 did not affect susceptibility to PBP1-targeted cephaloridine or PBP2-targeted imipenem. Similar results were obtained with PAO4089 overproducing E. coli PBP3, with the exception that there was no influence on the MICs or minimal bactericidal concentrations of cefsulodin and cefepime, which have very low affinities for E. coli PBP3. These data are consistent with the conclusion that PBP3 has to achieve a certain level of saturation, with beta-lactams targeted to this protein, to result in cell inhibition or death.

scholarly journals Evolution and resistance expression of MRSA. Evaluation of beta-lactam antibiotics against a set of isogenic strains with different types of phenotypic expression.

1995 ◽  
Vol 42 (4) ◽  
pp. 517-524 ◽  
Author(s):  
K Asada ◽  
Y Inaba ◽  
E Tateda-Suzuki ◽  
K Kuwahara-Arai ◽  
T Ito ◽  
...  
Keyword(s):  
Meca Gene ◽  
Phenotypic Expression ◽  
Aminoglycoside Antibiotic ◽  
Penicillin G ◽  
Binding Affinities ◽  
Penicillin Binding Protein ◽  
Beta Lactam ◽  
Beta Lactam Antibiotics ◽  
Mrsa Infection ◽  
Resistance Expression

Methicillin-resistant Staphylococcus aureus (MRSA) has two mechanisms of resistance to beta-lactam antibiotics; one is mediated by mecA gene expression, and the other by penicillinase production. It has been generally accepted in the clinical field that beta-lactam antibiotics are not the drugs of choice for MRSA infection. In this report, however, ampicillin and penicillin G were shown to have relatively good activity against MRSA if combined with a beta-lactamase inhibitor, sulbactam. These beta-lactam antibiotics were found to have relatively high binding affinities to PBP2', the mecA-encoded MRSA-specific penicillin-binding protein. The possible therapeutic application of sulbactam/ampicillin against MRSA infection in combination with arbekacin, an aminoglycoside antibiotic newly developed and introduced into clinical use in Japan, is discussed.

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