Genetic basis of molecular mechanisms in β-lactam resistant gram-negative bacteria

Abstract

Antibiotic-resistant bacteria are considered one of the major global threats to human and animal health. The most harmful of the resistant bacteria are β-lactamases producing Gram-negative species (β-lactamases). β-lactamases constitute a paradigm shift in the evolution of antibiotic resistance. Therefore, it is imperative to present a comprehensive review of the mechanisms responsible for the development of antimicrobial resistance. Resistance due to β-lactamases develops through to a variety of mechanisms, and the number of resistant genes is involved that can be transferred between bacteria, mostly via plasmids. Over time, these new molecular based resistance mechanisms have been progressively disclosed. The present review article provides information on the recent findings regarding the molecular mechanisms of resistance to β-lactams in Gram-negative bacteria, including CTX-M-type ESBLs with methylase activity, plasmids harbouring phages with β-lactam resistance genes, the co-presence of β-lactam resistant genes of unique combinations and the presence of β-lactam and non-β-lactam antibiotic-resistant

Extended-Spectrum Beta-Lactamases Producing Enterobacteriaceae in the USA Dairy Cattle Farms and Implications for Public Health

“…through horizontal gene transfer [ 50 ]. After mobilization of this gene from the chromosome into a plasmid, mutations lead to further diversification and provide the opportunity for expansion of hydrolytic activity to other extended-spectrum cephalosporins such as ceftazidime [ 51 ]. In animals, the CTX-M enzyme was first identified in 1988 from E. coli isolated from dogs’ feces in Japan [ 52 ].…”

Molecular Epidemiology of Extended-Spectrum Beta-Lactamase and AmpC Producing Enterobacteriaceae among Sepsis Patients in Ethiopia: A Prospective Multicenter Study

“…Generally, all beta-lactamase variants are classified into four classes, A (serine penicillinases), B (metallo-beta-lactamases), C (cephalosporinases) and D (oxacillinases), which give resistance to penicillins, most β-lactams, cephalosporins and cloxacillin, respectively [ 11 ]. Some key families of ESBL-encoding genes, such as bla CTX-M , bla TEM and bla SHV are grouped in class A [ 8 , 12 , 13 ].…”

“…Other ESBL genes include bla OXA , bla VEB , bla VER and bla GES [ 7 , 8 , 13 ]. The co-presence of ESBL genes in the same species is a significant threat of transfer to other species [ 11 ].…”

Molecular detection of some virulence genes of Proteus mirabilis in rheumatoid Ar-thritis patient’s urine and other clinical samples

“…Figure 3: Antibiotic Susceptibility test for Proteus mirabilis to 14 Antibiotics Salama et al, (2021) and the Iraqi study of Hussain, (2016) revealed that P.mirabilis recovered from different clinical specimens are characterized by multidrug resistant. According to Hussain et al,(2021), bacterial isolates can develop chromosomally β-lactamase enzyme, which hydrolyzes chemical compounds containing a β -lactam ring, causing resistance to β -lactam antibiotics. In the same way, horizontal gene transfer (HGT) is vital in -lactam resistance.…”