We read with interest the article by Chopra et al. (1) suggesting that empirical therapy with cefepime for bloodstream infections due to extended-spectrum-lactamase (ESBL)-producing Enterobacteriaceae is associated with excess mortality. The effectiveness of cefepime would be compromised by ESBL production, resulting in higher MICs (2, 3). Several beta-lactamase inhibitors (including clavulanat...

AmpC β-lactamases are enzymes that resistant to β-lactams, such as penicillin and cephalosporin, but not cefoxitin cefotetan. This study was conducted characterize in Enterobacteriaceae. included 200 cephalosporin-resistant Gram-negative isolates recovered from different samples between January 2015 December 2016. The were subjected phenotypic tests, those tested positive further analyzed by PC...

CTX-M-19 is a recently identified ceftazidime-hydrolyzing extended-spectrum beta-lactamase, which differs from the majority of CTX-M-type beta-lactamases that preferentially hydrolyze cefotaxime but not ceftazidime. To elucidate the mechanism of ceftazidime hydrolysis by CTX-M-19, the beta-lactam MICs of a CTX-M-19 producer, and the kinetic parameters of the enzyme were confirmed. We reconfirme...

The most common mechanism of resistance to β-lactam antibiotics in Gram-negative bacteria is the production of β-lactamases that hydrolyze the drugs. Class A β-lactamases are serine active-site hydrolases that include the common TEM, CTX-M, and KPC enzymes. The TEM enzymes readily hydrolyze penicillins and older cephalosporins. Oxyimino-cephalosporins, such as cefotaxime and ceftazidime, howeve...

A M182T substitution was discovered as a second-site suppressor of a missense mutation in TEM-1 b-lactamase. The combination of the M182T substitution with other substitutions in the enzyme indicates the M182T substitution is a global suppressor of missense mutations in b-lactamase. The M182T substitution also is found in natural variants of TEM-1 b-lactamase with altered substrate specificity ...

Background: β-lactams and carbapenems are the major antibiotics used to treat gram-negative bacteria non-fermenting bacilli. However, increasing production of β-lactamase carbapenemase limits therapeutic options. Our study aims determine resistant phenotypes these while describing their epidemiological aspect. Material Methods: This was a cross-sectional by consecutive enrollment from January 2...

Fungi are absorptive feeders and thus must colonize and ramify through their substrate to survive. In so doing they are in competition, particularly in the soil, with myriad microbes. These microbes use xenobiotic compounds as offensive weapons to compete for nutrition, and fungi must be sufficiently resistant to these xenobiotics. One prominent mechanism of xenobiotic resistance is through pro...