Antibiotic resistance in Enterobacteriaceae: mechanisms and clinical implications

Abstract

Resistance of the Enterobacteriaceae to antibiotics, especially of the β lactam type, is increasingly dominated by the mobilization of continuously expressed single genes that encode efficient drug modifying enzymes. Strong and ubiquitous selection pressure has seemingly been accompanied by a shift from "natural" resistance, such as inducible chromosomal enzymes, membrane impermeability, and drug efflux, to the modern paradigm of mobile gene pools that largely determine the epidemiology of modern antibiotic resistance. In this way, antibiotic resistance is more available than ever before to organisms such as Escherichia coli and Klebsiella pneumoniae that are important causes of major sepsis. Modulation of the phenotype by host bacteria makes gene transmission less obvious and may in part explain why tracking and control of carbapenem resistance has been particularly problematic in the Enterobacteriaceae. This review discusses the underlying principles and clinical implications of the mobility and fixation of resistance genes and the exploitable opportunities and potential threats arising from apparent limitations on diversity in these mobile gene pools. It also provides some illustrative paradoxes and clinical corollaries, as well as a summary of future options.

Klebsiella pneumoniae: Going on the Offense with a Strong Defense

“…The dissemination of and mechanisms of resistance by ESBLs and carbapenemases in K. pneumoniae and other bacteria are not the focus of this review, so we refer readers to the other excellent reviews (11,25). Here, however, we briefly summarize some of the major mechanisms of drug resistance found in K. pneumoniae.…”

“…It requires the carriage of these carbapenem resistance genes but often also requires the carriage of other ␤-lactamases and/or mutations in outer membrane proteins (OMPs) that render the bacteria more resistant to ␤-lactams, particularly in combination with the expression of a carbapenemase (10,31). ESBLs, which are also found worldwide, can also be caused by a number of ␤-lactamases, the most common of which are TEM, SHV, CTX-M, and OXA (11,25).…”

Molecular Identification and Growth Inhibition of Some Human Pathogenic Bacteria Isolated From King Fahad General Hospital, Jeddah

“…This became more serious in case of Gram-negative bacteria such as A. baumannii, E. coli and P. aeruginosa and Gram-positive S. aureus which were associated with pus and wound infections, due to extensive prescription and inadequate dose of antibiotics (Rice, 2006, Misic et al, 2014. Rapid spread of multidrug resistant bacteria poses a serious threat to public health due to the limited treatment options and the decrease in the discovery of new classes of antibiotics (Iredell et al, 2016).…”

Lactobacilli and Clove Essential Oil Against Menace of E.COLI: A Possible Solution for Antibiotic Resistance

“…Antibiotic resistance is more available now to organisms like E.coli. [26] The problems further worsen due to wrong management of the infection and/or over treatment. [13] Another revealing study showed 96% (4% gram positives) of total isolated microbes from UTI cases to be gram negative bacteria, among which E.coli was most prevalent.…”