Enterobacter spp.: pathogens poised to flourish at the turn of the century

Abstract

Knowledge of the genus Enterobacter and its role in human disease has expanded exponentially in recent years. The incidence of infection in the hospital and the community has increased. New clinical syndromes have been recognized. Enterobacter spp. have also been implicated as causes of other syndromes that traditionally have been associated almost exclusively with more easily treatable pathogens, such as group A streptococci and staphylococci. Rapid emergence of multiple-drug resistance has been documented in individual patients during therapy and in populations and environments with strong selective pressure from antimicrobial agents, especially the cephalosporins. Therapeutic options for patients infected with multiply resistant strains have become severely limited. Carbapenems or, alternatively, fluoroquinolones are the most predictively active options, although resistance to both classes has been observed on rare occasions. Enterobacter spp. appear well adapted for survival and even proliferation as the turn of the century approaches.

Substrate specificity of HMRZ-86 for β-lactamases, including extended-spectrum β-lactamases (ESBLs)

“…At least the differential between the activities of these AmpCs was not greater than that for ESBL and traditional penicillinase although the depressed microorganisms that produce AmpC resist thirdgeneration β-lactam antibiotics such as CAZ and CTX and monobactam antibiotics such as aztreonam (AZT). 16,17 Type CMY-2-producing microorganisms have often been detected in Europe, but the activity of the enzyme seemed to be weak, and this fi nding means that the resistance of AmpC did not depend on the expanded activity of the enzyme but on the amount. Thus, in the antibiotic resistance caused by AmpC, the most important point is whether the microorganism is the derepressed type, and the detection of a microorganism resistant to third-generation β-lactam antibiotics required induction promoter gene by β-lactam antibiotics.…”

Impact of Previous Use of Antibiotics on Development of Resistance to Extended-Spectrum Cephalosporins in Patients with Enterobacter Bacteremia

“…Resistance to ESCs, broad-spectrum penicillins, and aztreonam emerges in these species of Enterobacter following mutation in a chromosomal gene -ampD -that normally prevents high-level expression of the enzyme [4]. Emergence of resistance results from the selective pressure exerted by the drug used previously, which provides a survival advantage for the mutant over the wild type [5]. Therefore, previous use of ESCs was an independent risk factor for development of resistance to ESCs.…”

“…These organisms are capable of producing chromosomal β-lactamases. Transiently increased β-lactamase production occurs when Enterobacter species are exposed to β-lactam antibiotics, and constitutive high-level production occurs by mutation [3,4,5]. These characteristics are important factors to consider in the management of antibiotic-resistant Enterobacter infection.…”

Enterobacter Strains Might Promote Colon Cancer

“…As a gram negative organism they possess endotoxin. Antibiotic resistance can be observed among Enterobacter strains against b-lactam antibiotics and cephalosporins [4,12,30].…”