Development of β-lactam resistance, production of alginate and modulation of virulence factor expression that alters host immune responses are the hallmarks of chronic Pseudomonas aeruginosa infection in cystic fibrosis patients. In this study, we propose that a co-regulatory network exists between these mechanisms. We compared the promoter activities of ampR, algT/U, lasR, lasI, rhlR, rhlI and...

Active-site serine D,D-transpeptidases belonging to the penicillin-binding protein family (PBPs) have been considered for a long time as essential for peptidoglycan cross-linking in all bacteria. However, bypass of the PBPs by an L,D-transpeptidase (Ldt(fm)) conveys high-level resistance to β-lactams of the penam class in Enterococcus faecium with a minimal inhibitory concentration (MIC) of amp...

PURPOSE The appropriateness of combination therapy for infections caused by gram-negative organisms is examined. SUMMARY Mortality from Pseudomonas aeruginosa infection is particularly high; therefore, empirical regimens are often selected to ensure coverage for this organism. The initial use of combination antimicrobial therapy for gram-negative infections is usually justified by one of thre...

background: extended spectrum β-lactamases (esbls) and ampc β-lactamases enzyme are major sources of resistance to β-lactam antibiotics especially in enterobacteriaceae such as escherichia coli and klebsiella pneumoniae. increasing frequency of the co-existence of esbls with ampc-β-lactamases in bacteria is a serious threat for treating bacterial infections. conclusions: outbreak of isolates co...

Acquired resistance is through the production of AmpC Beta Lactamases (AmpC), Extended Spectrum Beta Lactamases (ESBL) and Metallo Beta-Lactamases Enzymes (MBL). Resistance to β-lactam antibiotics is associated with production of ESBL which can hydrolyze oxyimino β-lactams such as cefotaxime, ceftriaxone, ceftazidime and monobactams, however, without any effect on cephamycins, carbapenems and r...

Methicillin-resistant Staphylococcus aureus (MRSA) is a major multidrug resistant pathogen responsible for several difficult-to-treat infections in humans. Clinical Hetero-resistant (HeR) MRSA strains, mostly associated with persistent infections, are composed of mixed cell populations that contain organisms with low levels of resistance (hetero-resistant HeR) and those that display high levels...

BACKGROUND A high proportion of staphylococci isolated from pigs affected with exudative epidermitis were found to be resistant to β-lactam antimicrobials. The primary objective of this research was to investigate and characterize β-lactam resistance in Staphylococcus hyicus, Staphylococcus aureus and other staphylococci isolated from these pigs. RESULTS The antimicrobial resistance patterns ...

β-Lactam antibiotics are among the most widely used antibiotics against microbial pathogens. However, enzymatic hydrolysis of these antibiotics by bacterial β-lactamases is increasingly compromising their efficiency. Although new generation β-lactam antibiotics have been developed to combat antibiotic resistance, β-lactamases have also evolved along with the new variants of the substrate. A str...

BACKGROUND & OBJECTIVES Multidrug-resistance of methicillin-resistant Staphylococcus aureus (MRSA) is a serious therapeutical problem. Chalcones belong to a group of naturally occurring flavonoids, usually found in various plant species, and have potent antibacterial, antiviral and antifungal activities. The goal of this study was to evaluate the antibacterial effect of three newly-synthesized ...

Extended-spectrum β-lactamase (ESβL) enzymes are produced by certain bacteria as a mechanism of resistance to β-lactam and extended-spectrumβ-lactam antibiotics. Previous investigations have confirmed that M. oleifera contains several bioactive compounds. This study aimed at evaluating the in vitro antibacterial effects ethanolic methanolic leaf extracts on extended-spectrum producing bacteria....