conclusions: high percentage of hemolysins, biofilm and beta lactamase production by isolated staphylococci, suggests an important role of these virulence factors in the pathogenesis of isolated staphylococci from dermatitis lesions. the s. aureus isolates from wound infections, show a high sensitivity pattern to all examined antibiotics. only ciprofloxacin was found to be active against all is...

background :   imipenem-resistant gram negative bacteria, resulting from metallo-beta-lactamase (mbls)-producing strains have been reported to be among the important causes of nosocomial infections and of serious therapeutic problem worldwide. because of their broad range, potent carbapenemase activity and resistance to inhibitors, these enzymes can confer resistance to almost all beta-lactams....

BACKGROUND Pseudomonas aeruginosa is one of the most common causes of nosocomial infections. Resistance of P. aeruginosa to β-lactam antibiotics may be the result of acquired resistance through mutation and over production of various antibiotic inactivating enzymes. This research aimed to determine the prevalence of extended-spectrum β-lactamases (ESBL) and metallo β-lactamase (MBL) production ...

A total of 314 strains of Haemophilus, isolated from clinical samples, were studied for the production of beta-galactosidase and beta-xylosidase. None of the H. influenzae strains studied (9 beta-lactamase positive strains and 129 beta-lactamase negative strains) possessed these enzymes. Both enzymes were almost constantly observed among strains of H. paraphrophilus (10 strains studied) and of ...

Mechanism-based inactivators of b-lactamases are used to overcome the resistance of clinical pathogens to b-lactam antibiotics. This strategy can itself be overcome by mutations of the b-lactamase that compromise the effectiveness of their inactivation. We used PCR mutagenesis of the TEM-1 b-lactamase gene and sequenced the genes of 20 mutants that grew in the presence of ampicillin-clavulanate...

Ceftaroline is a new cephalosporin with broad-spectrum activity against Gram-positive and -negative organisms. The prodrug of ceftaroline, ceftaroline fosamil, combined with the β-lactamase inhibitor avibactam (formerly NXL104), was tested against Enterobacteriaceae strains producing Ambler class A, B, C, and D enzymes, including strains producing multiple enzymes, as well as Pseudomonas aerugi...

Among Escherichia coli organisms isolated at St. Thomas's Hospital during the years 1990 to 1994, the frequency of resistance to amoxicillin-clavulanic acid (tested by disk diffusion in a ratio of 2:1) remained constant at about 5% of patient isolates (10 to 15% of the 41 to 45% that were amoxicillin resistant). Mechanisms of increased resistance were determined for 72 consecutively collected s...

One of the mechanisms Klebsiella pneumoniae and Escherichia coli resistance to ?-lactam antibiotics is production ?-lactamase enzymes. Among these are AmpC ?-lactamases, which confer a class antibiotics. However, little known about ?-lactamases K. E. clinical isolates in Qazvin, Iran. This study was designed assess ??lactamases-producing strains also identify prevalence ??lactamases genes. Anti...