β-Lactamases inactivate β-lactam antibiotics by hydrolysis of their endocyclic β-lactam bond and are a major cause of antibiotic resistance in pathogenic bacteria. The zinc dependent metallo-β-lactamase enzymes are of particular concern since they are located on highly transmissible plasmids and have a broad spectrum of activity against almost all β-lactam antibiotics. We present here essential...

Microorganism-caused diseases are one of the greatest predicaments faced by world. The disease conditions worsened due to development microbial resistance against numerous antimicrobial agents like quinolones, vancomycin, macrolides, tetracyclines, β-lactam antibiotics, etc. There will always be a vital need discover new chemotherapeutic avert emergence and ideally shorten duration therapy...

The widespread use of antibiotics has resulted in a growing problem of antimicrobial resistance in the community and hospital settings. Antimicrobial classes for which resistance has become a major problem include the β-lactams, the glycopeptides, and the fluoroquinolones. In gram-positive bacteria, β-lactam resistance most commonly results from expression of intrinsic low-affinity penicillin-b...

Due to the emerging resistance against classical β-lactam-based antibiotics, a growing number of bacterial infections has become harder to treat. This alarming tendency necessitates continued research on novel antibacterial agents. Many classes of β-lactam antibiotics are characterized by the presence of the 3-aminoazetidin-2-one core, which resembles the natural substrate of the target penicil...

In most gram-negative bacteria, acquired multiresistance is conferred by large plasmids compiling numerous antimicrobial resistance genes. Here, we show an evolutionary alternative strategy used by Pasteurella multocida to become resistant to multiple clinically relevant antibiotics. Thirteen beta-lactam-resistant clinical isolates, concomitantly resistant to tetracyclines and/or streptomycin a...

Methicillin resistance in Staphylococcus aureus has been associated with alterations in the penicillin-binding proteins (PBPs). An intriguing property of all methicillin-resistant staphylococci is the dependence of resistance on the pH value of the growth medium. Growth of such bacteria at pH 5.2 completely suppressed the expression of methicillin resistance. We have examined the PBP patterns o...

Resistance to β-lactam antibiotics mediated by metallo-β-lactamases (MBLs) is a growing problem. We describe the use of protein-observe 19 F-NMR (PrOF NMR) to study the dynamics of the São Paulo MBL (SPM-1) from β-lactam-resistant Pseudomonas aeruginosa. Cysteinyl variants on the α3 and L3 regions, which flank the di-ZnII active site, were selectively 19 F-labeled using 3-bromo-1,1,1-trifluoroa...

The contribution of penicillin-binding protein 5 (PBP5) and the PBP5 synthesis repressor (Psr) to the beta-lactam resistance, growth, and cell autolysis of wild-type strain ATCC 9790 and resistant strain R40 of Enterococcus hirae was investigated by disruption or substitution of the corresponding pbp5 and psr genes by Campbell-type recombination. The resulting modifications were confirmed by hy...

The most common causes of death in neonatal period is infection (32%) followed by birth asphyxia (29%) and prematurity (24%).Neonatal infections currently cause 1.6 million deaths in developing countries (Choudhury et al., 2007). Multidrug resistant Gram negative bacilli belonging to the family Enterobacteriaceae have been increasingly responsible for infections among the neonates admitted to t...

The emergence of clinically relevant ?-lactam-resistant bacteria poses a serious threat to human health and presents major challenge for medical treatment. How opportunistic pathogenic acquire antibiotic resistance the prevalence antibiotic-resistant in environment are still unclear. In this study, we further confirmed that selective pressure heavy metals contributes increase ampicillin-resista...