Identification of Functional Regulatory Residues of theβ-Lactam Inducible Penicillin Binding Protein in Methicillin-ResistantStaphylococcus aureus

Mbah, Andreas N.; Isokpehi, Raphael D.

doi:10.1155/2013/614670

Cited by 5 publications

(2 citation statements)

References 86 publications

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“…Methicillin resistance in MRSA is due to the presence of mec-A gene, which encodes a low affinity penicillin binding protein (PBP)-2a or PBP2’ ( 7 ). Other genes—such as femA, femB can also contribute to methicillin resistance in MRSA ( 8 ).…”

Section: Introductionmentioning

confidence: 99%

Comparison of PCR and phenotypic methods for the detection of methicillin resistant Staphylococcus aureus

Madhavan¹,

Sachu²,

Balakrishnan³

et al. 2021

IJM

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Background and Objectives: Resistance to methicillin in methicillin resistant strains of Staphylococcus aureus (MRSA) is due to the presence of mec-A gene ,which encodes a low affinity penicillin binding protein (PBP)-2a or PBP2. Accurate and rapid identification of MRSA in clinical specimens is essential for timely decision on effective treatment. The aim of the study was to compare three different methods for detection of MRSA namely cefoxitin disc diffusion, CHROM agar MRSA and VITEK-2 susceptibility with PCR which is the gold standard reference method and to find the antibiotic susceptibility pattern of these isolates by VITEK-2. Materials and Methods: A Total of 100 non-duplicate S. aureus isolates were collected from different clinical samples among both outpatient and inpatients. Detection of MRSA among these isolates was done by cefoxitin disc diffusion, VITEK-2, CHROM agar MRSA and PCR. Results: The sensitivity and specificity of cefoxitin disc diffusion and Vitek was found to be 97.2% and 100%, while that of CHROM agar was found to be 100% and 78.6%. The overall prevalence of MRSA in our study by PCR was 72%. Conclusion: Based on the findings in our study, isolates which show cefoxitin zone diameter < 22 mm can be reported as MRSA. However, those isolates which have a zone diameter between 22-24 mm, should ideally be confirmed by PCR.

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Section: Introductionmentioning

confidence: 99%

Comparison of PCR and phenotypic methods for the detection of methicillin resistant Staphylococcus aureus

Madhavan¹,

Sachu²,

Balakrishnan³

et al. 2021

IJM

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“…However, in the case of beta-lactam antibiotics, a ligand-receptor interaction with the participation of a specific penicillin-binding protein (PBP), which recognizes an essential structural element of these medicinal substances, the beta-lactam ring, presents a unique opportunity for the development of bioassay methods. PBP in the bacterial membrane plays a key role in the antibacterial action of beta-lactams, forming a complex with them with subsequent chemical modification of the serine residue in the active center and the resulting loss of PBP transpeptidase function in the biosynthesis of peptidoglycans of the bacterial cell wall, which leads to the death of the microorganism [16][17][18]. The advantage of using the receptor in bioassay, in contrast to most antibodies, is the ability to recognize and bind a whole group of beta-lactams, while interaction occurs only with the active forms of these antibiotics, which have a whole beta-lactam ring.…”

Section: Introductionmentioning

confidence: 99%

Direct Conjugation of Penicillins and Cephalosporins with Proteins for Receptor Assays of Beta-Lactam Antibiotics

2022

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Abstract— Fifteen protein conjugates of penicillins and cephalosporins containing amino- and/or carboxylic groups in the initial structures have been synthesized in the reactions with human serum albumin or ovalbumin using 1-ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride (EDC) or a combination of EDC and N-hydroxysulfosuccinimide at various ratios of the base reagents. A comparative study of conjugates composition and properties has been carried out by UV spectroscopy, mass spectrometry and a ligand-receptor assay. It was shown that the antibiotic residue content of the macromolecules obtained varied from 1 to 22, the beta-lactam cycle remained intact assuring specific interactions of the conjugates with a penicillin-binding protein. In two developed models of receptor bioanalytic systems, an ampicillin conjugate onto a solid phase binds to penicillin-binding protein complexed with a monoclonal antibody, which was detected by an immunoenzyme label in microplate wells or gold nanoparticles on test strips. Conjugated ampicillin binding to the receptor was competitively inhibited by beta-lactam antibiotics added to the liquid phase, and analytical sensitivities relative to penicillin G were 0.05 and 1 ng/mL for microplate and receptor chromatographic systems, respectively.

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Impact of Mutation on the Structural Stability and the Conformational Landscape of Inhibitor-Resistant TEM β-Lactamase: A High-Performance Molecular Dynamics Simulation Study

Mukherjee¹,

Mukherjee²,

Mishra

2021

J. Phys. Chem. B

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Gain-of-function mutations and structural adjustment toward β-lactamase inhibitors in the TEM-type β-lactamases among the uropathogenic E. coli (UPEC) culminate in treatment complications and demands detailed investigation. In this study, uncharacterized amino acid substitutions, M69L/I84V/W165G/V184A/V262I/N276S, in inhibitor-resistant TEM (IRT) β-lactamase isolated from clinical UPEC were subjected to extensive molecular dynamics (EMD) simulations for 100 ns to estimate parameters such as root-mean-square deviation (RMSD), root-mean-square fluctuation (RMSF), the radius of gyration (R g), contour plot (R g/RMSD), secondary structure element (SSE), etc. Residue interaction networks, principal component analysis (PCA), and correlation heatmaps were generated to predict the relation between functionally important atomic motions to uncover the structural stability of the mutants. To avoid the false positive conclusion of the simulation study, we performed three identically parameterize replicas of 100 ns each. Alterations in hydrophobic interactions resulted in conformation changes exhibited as comparable residue interaction networks. Besides, PCA and porcupine plot analysis based on the ensemble of structure from molecular dynamics trajectories revealed the collective atomic motions of the IRT variants that impart structural flexibility to their active site loop. This study conducted on IRT mutants that delineate intricate protein motions contributes to their stability and folding, which is an absolute necessity for designing candidate molecules owing to the clinical threat of emerging resistance against potent β-lactam antibiotics.

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Identification of Functional Regulatory Residues of theβ-Lactam Inducible Penicillin Binding Protein in Methicillin-ResistantStaphylococcus aureus

Cited by 5 publications

References 86 publications

Comparison of PCR and phenotypic methods for the detection of methicillin resistant Staphylococcus aureus

Comparison of PCR and phenotypic methods for the detection of methicillin resistant Staphylococcus aureus

Direct Conjugation of Penicillins and Cephalosporins with Proteins for Receptor Assays of Beta-Lactam Antibiotics

Impact of Mutation on the Structural Stability and the Conformational Landscape of Inhibitor-Resistant TEM β-Lactamase: A High-Performance Molecular Dynamics Simulation Study

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