Antibiotics, Resistome and Resistance Mechanisms: A Bacterial Perspective

Abstract

History of mankind is regarded as struggle against infectious diseases. Rather than observing the withering away of bacterial diseases, antibiotic resistance has emerged as a serious global health concern. Medium of antibiotic resistance in bacteria varies greatly and comprises of target protection, target substitution, antibiotic detoxification and block of intracellular antibiotic accumulation. Further aggravation to prevailing situation arose on observing bacteria gradually becoming resistant to different classes of antibiotics through acquisition of resistance genes from same and different genera of bacteria. Attributing bacteria with feature of better adaptability, dispersal of antibiotic resistance genes to minimize effects of antibiotics by various means including horizontal gene transfer (conjugation, transformation, and transduction), Mobile genetic elements (plasmids, transposons, insertion sequences, integrons, and integrative-conjugative elements) and bacterial toxin-antitoxin system led to speedy bloom of antibiotic resistance amongst bacteria. Proficiency of bacteria to obtain resistance genes generated an unpleasant situation; a grave, but a lot unacknowledged, feature of resistance gene transfer.

Pathogenomic Analysis of a Novel Extensively Drug-Resistant Citrobacter freundii Isolate Carrying a blaNDM-1 Carbapenemase in South Africa

“…This supports a possible exchange of genetic traits via horizontal transfer between Enterobacterales. Class 1 integrons, reported to be associated with multiple classes of antibiotic resistome, including β-lactams, quinolones, and aminoglycosides worldwide, were found [29]. However, the full mobile gene cassettes and integron genetic structure could not be determined as they were truncated into different contigs during the assembly process.…”

Antimicrobials

“…Probably more problematic than this is the acquisition of resistance genes, either from other bacteria or the environment (Sultan et al 2018). This most commonly occurs in one of three ways (Gillings and Stokes 2012): 1.…”

Constructing and deconstructing the bacterial cell wall

“…The antibiotic‐producing microbe ensures its immunity by the simultaneous creation of a means to subvert the mechanism of its antibiotic. Over decades of time these existential immunity solutions have escaped by horizontal gene transfer, and the stress responses activated by antibiotics have effected mutations in the target that subvert the antibiotic mechanism . The result is antibiotic‐resistant bacteria.…”

“…Over decades of time these existential immunity solutions have escaped by horizontal gene transfer, [22][23][24][25] and the stress responses activated by antibiotics have effected mutations in the target that subvert the antibiotic mechanism. [26][27][28][29] The result is antibiotic-resistant bacteria. And indeed, less than a century after the widespread medical use of antibiotics, extensively resistant-and thus powerfully pathogenic bacteriahave arrived.…”