Introduction: Extended spectrum β-lactamases are the group of β-lactamase enzymes which confer resistance to oxyimino-cephalosporins and monobactams.
 Study Design: Cross-sectional prospective study.
 Place Duration Study: This study was conducted over a period 2 years (September 2018 April 2020) at microbiology laboratory Nepal Mediciti Hospital.
 Methodology: Clinical samples w...

background and objectives: the pathogenic strains of escherichia coli cause severe septicemia, urinary tract infection and wound sepsis. resistance of this organism to the expanded-spectrum cephalosporins occurs via the production of extended-spectrum β-lactamases (esbls) such as tem and shv. these enzymes hydrolyze oxyimino cephalosporins (cefotaxime, ceftazidime) and monobactams (aztreonam). ...

Background The extended spectrum ß-lactamases (ESBL) are enzymes that produce resistance to ß-lactam antibiotics, including penicillins, wide spectrum cephalosporins and aztreonam, by cleavage of ß-lactam ring (BUSH & JACOBY, 2010). Since ESBL-producing bacteria are frequently associated with nosocomial infections, treatment options are becoming increasingly limited (RAWAT & NAIR, 2010). In thi...

Macrolide antibiotics such as erythromycin are clinically important polyketide natural products. We have engineered a recombinant strain of Escherichia coli that produces small but measurable quantities of the bioactive macrolide 6-deoxyerythromycin D. Bioassay-guided evolution of this strain led to the identification of an antibiotic-overproducing mutation in the mycarose biosynthesis and tran...

Ro 13-9904 has high in vitro activity, as does cefotaxime, against 57 Haemophilus influenzae and 60 Neisseria gonorrhoeae strains, including 5 and 11 beta-lactamase-producing strains in each group, respectively.

The stability of DA-1131 to renal dipeptidase (RDPase) (EC 3.4.13.19) was compared with that of imipenem and meropenem by V(max)/K(m) ratios as an index of the enzyme's preference for substrates. Our results showed a decreasing order of imipenem (6.24), meropenem (2.41), and DA-1131 (1.39). The biochemical evaluation of DA-1131 as the least preferred substrate of RDPase suggests its potential u...

Bleomycins (BLMs) are antitumor antibiotics that in the presence of iron and oxygen mediate DNA damage by 4'-hydrogen atom abstraction of pyrimidines 3' to guanines. The resulting 4'-deoxyribose radicals can be trapped by O2 and ultimately result in the formation of base-propenal and gapped DNA with 3'-phosphoglycolate (3'-PG) and 5'-phosphate (5'-P) ends. The role of this lesion in triggering ...

Susceptibilities to beta-lactam antibiotics of five VIM-1-producing Klebsiella pneumoniae isolates were determined by broth microdilution, Etest, disk diffusion, and the automated systems Vitek 2, Phoenix, and MicroScan. Significant discrepancies were observed in the determination of susceptibility to imipenem and meropenem. Interpretation problems by the automated systems were also noted.

Maduropeptin, a complex of new macromolecular antitumor antibiotics, is a metabolite of Actinomadura madurae H710-49. The active components maduropeptins A1, A2 and B are acidic chromopeptides with MW of around 22,500 and composed of 14 types of amino acids and an unstable chromophore. The antibiotics are active in vitro against Gram-positive bacteria and highly cytotoxic to tumor cells. They p...