Bacterial resistance to beta-lactam antibiotics: crystal structure of beta-lactamase from Staphylococcus aureus PC1 at 2.5 A resolution

Science ◽  
1987 ◽  
Vol 236 (4802) ◽  
pp. 694-701 ◽  
Author(s):  
O Herzberg ◽  
J Moult
Keyword(s):  
Crystal Structure ◽  
Staphylococcus Aureus ◽  
Bacterial Resistance ◽  
Beta Lactamase ◽  
Beta Lactam ◽  
Beta Lactam Antibiotics

scholarly journals beta-Lactamases in laboratory and clinical resistance.

1995 ◽  
Vol 8 (4) ◽  
pp. 557-584 ◽  
Author(s):  
D M Livermore
Keyword(s):  
Bacterial Resistance ◽  
Beta Lactamase ◽  
Beta Lactam ◽  
Beta Lactams ◽  
Producer Strain ◽  
Phenotypic Properties ◽  
Beta Lactamases ◽  
Beta Lactam Antibiotics ◽  
Clinical Resistance ◽  
Gram Negative Organisms

beta-Lactamases are the commonest single cause of bacterial resistance to beta-lactam antibiotics. Numerous chromosomal and plasmid-mediated types are known and may be classified by their sequences or phenotypic properties. The ability of a beta-lactamase to cause resistance varies with its activity, quantity, and cellular location and, for gram-negative organisms, the permeability of the producer strain. beta-Lactamases sometimes cause obvious resistance to substrate drugs in routine tests; often, however, these enzymes reduce susceptibility without causing resistance at current, pharmacologically chosen breakpoints. This review considers the ability of the prevalent beta-lactamases to cause resistance to widely used beta-lactams, whether resistance is accurately reflected in routine tests, and the extent to which the antibiogram for an organism can be used to predict the type of beta-lactamase that it produces.

scholarly journals The molecular phenomena of the blaZ genes forming betalactamase enzymes structure in Staphylococcus aureus resistant to beta-lactam antibiotics (ampicillin)

2010 ◽  
Vol 43 (3) ◽  
pp. 146
Author(s):  
Mieke Satari
Keyword(s):  
Infectious Disease ◽  
Staphylococcus Aureus ◽  
Point Of View ◽  
Base Substitution ◽  
Beta Lactamase ◽  
Beta Lactam ◽  
Purine Base ◽  
Pyrimidine Base ◽  
Nucleotide Base ◽  
Beta Lactam Antibiotics

Background: Nowadays, infectious disease still an important problem. One of the bacteria causing infectious diseases is Staphylococcus aureus (S. aureus). In the effort to deal with infections caused by S. aureus, beta-lactam antibiotics, such as ampicillin, are used. In fact, it is unfortunately known that many of S. aureus bacteria are resistant to this group of antibiotics. Because of nucleotide base changes in the structure of the genes blaZ which encode beta-lactamase enzymes in S. aureus. Purpose: The objective of this study was to analyze the nucleotide base changes in the structure of the genes blaZ forming beta-lactamase enzymes in S. aureus resistant to ampicillin based on molecular point of view. Methods: Molecular examinations was conducted by isolating the genes, forming beta-lactamase enzyme, which length was 845bp, from 7 isolates of S. aureus resistant to ampicillin by using PCR technique. The results of blaZ amplification were then subjected to homology by using Tn 552 of S. aureus obtained from bank of genes. Results: Based on the result of the homology, it was found that there was a change in purine base TG, which was a pyrimidine base at the -37 position of the initial codon of blaZ. This change, however, did not affect the strength of the promoter since the number of A and T is still more than the number of G and C. In the structure of the blaZ gene there was even no mutation or deletion or nucleotide base substitution found, so it would not affect the effectiveness of beta-lactamase enzyme. Conclusion: It can be concluded that the resistance of S. aureus towards ampicillin was not caused by nucleotide base deletion/substation. It is suspected that there were other causes leading to the resistance, including the overproduction of beta-lactamase enzyme of the blaZ gene, causing the degradation of beta-lactam antibiotics.Latar belakang: Penyakit infeksi sampai saat ini masih merupakan masalah. Salah satu bakteri penyebab infeksi yaitu Staphylococcus aureus (S. aureus). Upaya menangani infeksi yang disebabkan S. aureus dapat menggunakan antibiotik golongan betalaktam, salah satunya ampisilin. Pada kenyataannya banyak S. aureus resisten terhadap antibiotik ini. Salah satu penyebab timbulnya resistensi ampisilin terhadap S. aureus yaitu adanya dugaan perubahan basa nukleotida dari gen struktur (blaZ) yang mengkode enzim betalaktamase. Tujuan: Untuk menganalisis perubahan basa nukleotida gen struktur pembentuk enzim betalaktamase pada S. aureus yang resisten ampisilin ditinjau secara molekuler. Metode: Pemeriksaan enzim betalaktamase secara molekuler dilakukan dengan mengisolasi gen pembentuk ensim betalaktamase (blaZ) yang memiliki panjang 845 pb terhadap 7 isolat S. aureus hasil isolasi yang berasal dari abses yang resisten terhadap ampisilin dengan mengunakan PCR . Hasil amplifikasi blaZ kemudian dilakukan homologi dengan Tn 552 S. aureus yang diperoleh dari bank gen. Hasil: Hasil homologi ditemukan adanya perubahan basa purin T  G yang merupakan basa pirimidin pada posisi –37 dari kodon awal blaZ. Perubahan ini tidak mempengaruhi kekuatan promoter karena jumlah A dan T masih lebih banyak dari G dan C. Pada gen struktur blaZ ini tidak terdapat adanya mutasi ataupun delesi maupun subsitusi basa nukleotida hingga tidak akan mempengaruhi efektifitas kerja enzim betalaktamase. Kesimpulan: Terjadinya resisten S. aureus terhadap ampisilin bukan disebabkan adanya mutasi maupun delesi/ subsitusi basa nukleotida dari blaZ namun diduga adanya sebab lain yaitu produksi berlebih enzim betalaktamase hingga semua antibiotik betalaktam akan didegradasi oleh enzim betalaktamase.

Molecular Characterization of Methicillin Resistant and Extended Spectrum β-Lactamase Staphylococcus aureus Isolated from Burn Patients

2020 ◽  
pp. 145-151
Author(s):  
Shawnm Ahmed Aziz
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistance ◽  
Vancomycin Resistance ◽  
World Health ◽  
Molecular Technique ◽  
Burn Patients ◽  
Beta Lactamase ◽  
Beta Lactam ◽  
Extended Spectrum Beta Lactamase ◽  
Extended Spectrum

Antibiotic resistance has become a major world health challenge and has limited the ability of physician's treatment. Staphylococcus aureus the most notorious pathogens causes morbidity and mortality especially in burn patients. However, Staphylococcus aureus rapidly acquired resistance to multiple antibiotics. Vancomycin, a glycopeptide antibiotic remains a drug of choice for treatment of severe Methicillin Resistance S. aureus infections. This study aimed to detect the emergence of beta-lactam and glycopeptide resistance genes. 50 clinical specimens of S. aureus collected from burn patients in burn and plastic surgery units in Sulaimani-Iraq city. All specimens were confirmed to be positive for S. aureus. All the isolates were assessed for their susceptibility to different antibiotics depending on NCCL standards, followed by Extended Spectrum Beta Lactamase detection by double disk diffusion synergy test. The production of β- lactamases was evaluated in the isolated strains by several routine methods and polymerase chain reaction. Among the isolates 94% were Methicillin resistance and 34.28% were Extended Spectrum Beta Lactamase producer. PCR based molecular technique was done for the bla genes related to β- lactamase enzymes by the specific primers, as well as genes which related to reduced sensitivity to Vancomycin were detected. The results indicated that all isolated showed the PBP1, PBP2, PBP3, PBP4, trfA and trfB, graSR, vraS except the vraR gene and the prolonged therapy of Methicillin resistance infection with teicoplanin have been associated with progress of resistance and the rise of tecoplanin resistance may be a prologue to evolving Vancomycin resistance. In conclusion, beta-lactam over taking can rise Vancomycin- Intermediate S. aureus strains leading to appearance of Vancomycin resistance although the treatment of Vancomycin resistant infections is challenging.

scholarly journals Growing Menace of Antibacterial Resistance in Clinical Isolates ofPseudomonas aeruginosain Nepal: An Insight of Beta-Lactamase Production

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Shamshul Ansari ◽  
Rabindra Dhital ◽  
Sony Shrestha ◽  
Sangita Thapa ◽  
Ram Puri ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibiotic Resistance ◽  
Opportunistic Pathogen ◽  
Resistance Rate ◽  
Diffusion Method ◽  
Beta Lactamase ◽  
Beta Lactam ◽  
Beta Lactam Antibiotics ◽  
Microbiological Methods ◽  
Immunosuppressed Patients

Introduction. Pseudomonas aeruginosais the most frequently isolated organism as it acts as the opportunistic pathogen and can cause infections in immunosuppressed patients. The production of different types of beta-lactamases renders this organism resistant to many commonly used antimicrobials. Therefore, the aim of this study was to document the antibiotic resistance rate inPseudomonas aeruginosaisolated from different clinical specimens.Methods. Pseudomonas aeruginosarecovered was identified by standard microbiological methods. Antibiotic susceptibility testing was performed by modified Kirby-Bauer disc diffusion method following Clinical and Laboratory Standard Institute (CLSI) guidelines and all the suspected isolates were tested for the production of ESBLs, MBLs, and AmpC.Results.Out of total (178) isolates, 83.1% were recovered from the inpatient department (IPD). Majority of the isolates mediated resistance towards the beta-lactam antibiotics, while nearly half of the isolates were resistant to ciprofloxacin. Most of the aminoglycosides used showed resistance rate up to 75% but amikacin proved to be better option. No resistance to polymyxin was observed. ESBLs, MBLs, and AmpC mediated resistance was seen in 33.1%, 30.9%, and 15.7% isolates, respectively.Conclusions. Antibiotic resistance rate and beta-lactamase mediated resistance were high. Thus, regular surveillance of drug resistance is of utmost importance.

scholarly journals A metallo-beta-lactamase with both beta-lactamase and ribonuclease activity is linked with traduction in giant viruses

2019 ◽  
Author(s):  
Philippe Colson ◽  
Lucile Pinault ◽  
Said Azza ◽  
Nicholas Armstrong ◽  
Eric Chabriere ◽  
...  
Keyword(s):  
Acanthamoeba Castellanii ◽  
Deep Ocean ◽  
Penicillin G ◽  
Beta Lactamase ◽  
Beta Lactam ◽  
Strong Activity ◽  
Beta Lactam Antibiotics ◽  
Double Stranded Dna ◽  
Giant Viruses ◽  
Hydrolysis Of

ABSTRACTEnzymatic proteins with a metallo-beta-lactamase (MBL) fold have been essentially studied in bacteria for their activity on beta-lactam antibiotics. However, the MBL fold is ancient and highly conserved, and these proteins are capable of cleaving a broad range of substrates. It has recently been shown that MBLs are present in a wide array of cellular organisms, including eukaryotes and archaea. We show here that Tupanvirus deep ocean, a giant virus, also encodes a protein with a MBL fold. Phylogeny showed its clustering with transfer ribonucleases (RNases) and the presence of orthologs in other giant viruses, mainly those harboring the largest sets of translation components. In addition, it suggests an ancient origin for these genes and a transfer between giant viruses and Acanthamoeba spp., a host of many giant viruses. Biologically, after its expression in Escherichia coli, the tupanvirus protein was found to hydrolyse nitrocefin, a chromogenic beta-lactam. We also observed an hydrolysis of penicillin G (10 μg/mL) and detected the metabolite of penicillin G hydrolysis, benzylpenilloic acid. This was inhibited by sulbactam, a beta-lactamase inhibitor. In addition, we tested the degradation of single-stranded DNA, double-stranded DNA, and RNAs, and observed a strong activity on RNAs from seven bacteria with G+C varying from 42% to 67%, and from Acanthamoeba castellanii, the tupanvirus host. This was not inhibited by sulbactam or ceftriaxone. RNase activity was estimated to be 0.45±0.15 mU/mg using a fluorescence-based assay. Our results still broaden the range of hosts of MBL fold proteins and demonstrate that such protein can have dual beta-lactamase/nuclease activities. We suggest that they should be annotated according to this finding to avoid further confusion.

scholarly journals In Vivo Activity of QPX7728, an Ultrabroad-Spectrum Beta-Lactamase Inhibitor, in Combination with Beta-Lactams against Carbapenem-Resistant Klebsiella pneumoniae

2020 ◽  
Vol 64 (11) ◽  
Author(s):  
Mojgan Sabet ◽  
Ziad Tarazi ◽  
David C. Griffith
Keyword(s):  
Klebsiella Pneumoniae ◽  
Beta Lactamase ◽  
Beta Lactam ◽  
Beta Lactams ◽  
Bacterial Killing ◽  
Clinical Issue ◽  
Content Type ◽  
Beta Lactam Antibiotics ◽  
Carbapenem Resistant ◽  
Lactamase Inhibitor

ABSTRACT Resistance to beta-lactams has created a major clinical issue. QPX7728 is a novel ultrabroad-spectrum cyclic boronic acid beta-lactamase inhibitor with activity against both serine and metallo-beta-lactamases developed to address this resistance for use in combination with beta-lactam antibiotics. The objective of these studies was to evaluate the activity of QPX7728 in combination with multiple beta-lactams against carbapenem-resistant Klebsiella pneumoniae isolates in a neutropenic mouse thigh infection model. Neutropenic mice were infected with strains with potentiated beta-lactam MICs of ≤2 mg/liter in the presence of 8 mg/liter QPX7728. Two strains of carbapenem-resistant K. pneumoniae were tested with aztreonam, biapenem, cefepime, ceftazidime, ceftolozane, and meropenem alone or in combination with 12.5, 25, or 50 mg/kg of body weight of QPX7728 every 2 hours for 24 hours. Treatment with all beta-lactams alone either was bacteriostatic or allowed for bacterial growth. The combination of QPX7728 plus each of these beta-lactams produced bacterial killing at all QPX7728 doses tested. Overall, these data suggest that QPX7728 administered in combination with different partner beta-lactam antibiotics may have utility in the treatment of bacterial infections due to carbapenem-resistant K. pneumoniae.

scholarly journals A TEM-derived extended-spectrum beta-lactamase in Pseudomonas aeruginosa.

1996 ◽  
Vol 40 (11) ◽  
pp. 2488-2493 ◽  
Author(s):  
P Mugnier ◽  
P Dubrous ◽  
I Casin ◽  
G Arlet ◽  
E Collatz
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Clinical Strain ◽  
Beta Lactamase ◽  
Beta Lactam ◽  
Aminoglycoside Resistance ◽  
Double Mutation ◽  
Extended Spectrum Beta Lactamase ◽  
Beta Lactam Antibiotics ◽  
Extended Spectrum ◽  
High Level

A clinical strain of Pseudomonas aeruginosa, PAe1100, was found to be resistant to all antipseudomonal beta-lactam antibiotics and to aminoglycosides, including gentamicin, amikacin, and isepamicin. PAe1100 produced two beta-lactamases, TEM-2 (pI 5.6) and a novel, TEM-derived extended-spectrum beta-lactamase called TEM-42 (pI 5.8), susceptible to inhibition by clavulanate, sulbactam, and tazobactam. Both enzymes, as well as the aminoglycoside resistance which resulted from AAC(3)-IIa and AAC(6')-I production, were encoded by an 18-kb nonconjugative plasmid, pLRM1, that could be transferred to Escherichia coli by transformation. The gene coding for TEM-42 had four mutations that led to as many amino acid substitutions with respect to TEM-2: Val for Ala at position 42 (Ala42), Ser for Gly238, Lys for Glu240, and Met for Thr265 (Ambler numbering). The double mutation Ser for Gly238 and Lys for Glu240, which has so far only been described in SHV-type but not TEM-type enzymes, conferred concomitant high-level resistance to cefotaxime and ceftazidime. The novel, TEM-derived extended-spectrum beta-lactamase appears to be the first of its class to be described in P. aeruginosa.

Sign in / Sign up

Export Citation Format

Share Document