Β-lactam antibiotics

This study investigated adsorption of beta-lactam antibiotic Amoxicillin (AMX) on a new material of cerium oxide-coated nanosilica (CeO2-coated SiO2). The CeO2-coated SiO2 based on rice husk, was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM).

6p vikwong 29-09-2024 2 0   Download

Amoxicillin (AMX) is a highly antibiotic resistance so that many studies focus on the removal of AMX in water environment. The present study investigated adsorptive removal of beta-lactam antibiotic AMX using a cationic surfactant, cetyltrimethylamonium bromide (CTAB) modified nanosilica (CMNS).

5p vikwong 29-09-2024 2 0   Download

Group B streptococcus (GBS) is known as a commensal flora in human gastrointestinal and genitourinary tracts. This study aimed to determine the antibiotic resistance of GBS strains isolated and to determine the serotype distribution of isolated GBS strains.

5p vifaye 20-09-2024 4 0   Download

Among the other 12 inpatient MRSA isolates which had the pvl gene, nine were sensitive to most of the non- beta lactam antibiotics, whereas remaining three were resistant to most of the antibiotics except vancomycin and linezolid. The presence of pvl gene can no longer be used to discriminate between CA-MRSA and HA-MRSA.

5p kequaidan7 01-09-2020 13 2   Download

Penicillin acylase of Escherichia coli catalyses the hydrolysis and synthesis of b-lactam antibiotics. To study the role of hydrophobic residues in these reactions, we have mutated three active-site phenylalanines. Mutation of aF146, bF24 and bF57 to Tyr, Trp, Ala or Leu yielded mutants that were still capable of hydrolysing the chromogenic substrate 2-nitro-5-[(phenylacetyl)amino]-benzoic acid. Mutations on positions aF146 and bF24 influenced both the hydrolytic and acyl transfer activity.

8p research12 01-06-2013 31 3   Download

Penicillin acylase catalyses the hydrolysis and synthesis of semisyntheticb-lactam antibiotics via formation of a cova-lent acyl-enzyme intermediate. The kinetic and mechanistic aspects of these reactions were studied. Stopped-flow experiments with the penicillin and ampicillin analogues 2-nitro-5-phenylacetoxy-benzoic acid (NIPAOB) and D-2-nitro-5-[(phenylglycyl)amino]-benzoic acid (NIPGB) showed that the rate-limiting step in the conversion of penicillin G and ampicillin is the formation of the acyl-enzyme....

9p tumor12 20-04-2013 51 2   Download

The penicillin-binding proteins (PBPs) are ubiquitous bac-terial enzymes involved in cell wall biosynthesis,and are the targets of theb-lactam antibiotics. The low molecular mass Neisseria gonorrhoeaePBP 4 (NG PBP 4) is the fourthPBP revealed in the gonococcal genome. NG PBP 4 was cloned, overexpressed,purified,and characterized for b-lactam binding,DD-carboxypeptidase activity,acyl-donor substrate specificity,transpeptidase activity, inhibitionby a number of active site directed reagents,and pHprofile....

10p dell39 03-04-2013 37 3   Download

The metallo-b-lactamase (MBL) GOB-1 was expressed via a T7 expression system in Escherichia coliBL21(DE3). The MBL was purified to homoge-neity and shown to exhibit a broad substrate profile, hydrolyzing all the tested b-lactam compounds efficiently.

12p cosis54 05-01-2013 43 4   Download

Huntington’s disease (HD) is an inherited neurodegenerative disorder characterized by cortico-striatal dysfunction and loss of glutamate uptake. At 7 weeks of age, R6/2 mice, which model an aggressive form of juvenile HD, show a glutamate-uptake deficit in striatum that can be reversed by treatment with ceftriaxone, a b-lactam antibiotic that increases GLT1 expression. Only at advanced ages ( 11 weeks), however, do R6/2 mice show an actual loss of striatal GLT1. Here, we tested whether ceftriaxone can reverse the decline in GLT1 expression that occurs in older R6/2s.

5p toshiba23 18-11-2011 51 3   Download

Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học quốc tế cung cấp cho các bạn kiến thức về ngành y đề tài: Beta-lactam antibiotics in continuous infusion in critically ill patients...

2p coxanh_7 31-10-2011 66 2   Download

Inpatient Therapy Pneumococcal pneumonia is readily treatable with β-lactam antibiotics. The conventional dosages shown in Table 128-5 are acceptable against intermediately resistant strains and against many or most fully resistant isolates. Recommended agents include ceftriaxone and cefotaxime. Ampicillin is also widely used, usually in the form of ampicillin/sulbactam. The likely efficacy of newer quinolones such as moxifloxacin, macrolides such as azithromycin, and clindamycin is discussed above.

5p colgate_colgate 21-12-2010 78 3   Download

Pneumococcal Infections: Treatment Antibiotic Susceptibility β-Lactam antibiotics, the cornerstone of therapy for serious pneumococcal infection, bind covalently to the active site and thereby block the action of enzymes (endo-, trans-, and carboxypeptidases) needed for cell-wall synthesis. Because these enzymes were identified by their reaction with radiolabeled penicillin, they are called penicillin-binding proteins. Until the late 1970s, virtually all clinical isolates of S. pneumoniae were susceptible to penicillin (i.e., were inhibited in vitro by concentrations of ...

5p colgate_colgate 21-12-2010 63 2   Download

Introduction: β-Lactum antibiotics constitute an important class of antibacterial agents being used extensively for both humans and food-producing animals to treat or prevent infections. The drugs occasionally cause human deaths due to anaphylactic shock during medical treatments, especially when they are parenterally administered without their prior intracutaneous tests. These cases are usually handled as medical accidents (malpractice), and subjected to autopsies and analysis of the drugs used. These antibiotics are composed of cephems ( Table 10.1) and penicillins ( Table 10.

8p bigbaby87 01-09-2010 103 6   Download